WATER POLLUTION CONTROL RESEARCH SERIES • 12040 FES 07/71
SLUDGE MATERIAL RECOVERY SYSTEM FOR
MANUFACTURERS OF PIGMENTED PAPERS
U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a central source of
information on the research, development, and demonstration
activities in the water research program of the Environmental
Protection Agency, through in-house research and grants and
contracts with Federal, state, and local agencies, research
institutions, and industrial organizations.
Inquiries pertaining to Water Pollution Control Research Reports
should be directed to the Chief, Publications Branch (Water),
Research Information Division, R&M, Environmental Protection
Agency, Washington, D. C. 20460
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SLUDGE MATERIAL RECOVERY SYSTEM FOR
MANUFACTURERS OF PIGMENTED PAPERS
by
S. D. Warren
A Division of Scott Paper Company
Environmental Improvement Department
89 Cumberland Street
Westbrook, Maine 04092
for the
Office of Research and Monitoring
ENVIRONMENTAL PROTECTION AGENCY
Program Number 12040 FES
July 1971
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EPA Review Notice
This report has been reviewed by the Environmental Protection
Agency, and approved for publication. Approval does not
signify that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, nor does mention
of trade names or commercial products constitute endorsement or
recommendation for use.
ii
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ABSTRACT
Disposal of the sludge that results from primary treatment
of waste waters generated during the manufacture of coated
and/or filled papers has caused many problems.
A process has been developed and tested in a full scale mill
trial wherein the pigment present in the waste sludge was
reclaimed through incineration of the volatile components
of the sludge. In essence, the process consisted of opera-
tions in which the sludge resulting from the primary treat-
ment process was diluted to less than 0.75% solids, centri-
cleaned, dewatered to 30% solids, shredded, dried, and burned
in a rotary kiln. The ash that resulted - the pigment - was
then pulverized and used as filler pigment in the papermaking
process.
During the trial it was found that a pigment of acceptable
abrasiveness and a GE brightness of 84-85% could be produced
provided that sludge centricleaning was practiced and the
temperature in the kiln was kept below 1600 F.
A full scale system capable of processing 40 tons per day
(dry basis) primary treatment sludge would produce reusable
filler grade pigment at a net cost of $50 per ton. When
compared to the delivered cost of virgin filler clay ($38
per ton) it can readily be seen that full scale pigment
recovery utilizing this system is not economically justi-
fiable at this time.
This report was submitted in fulfillment of Project Number
12040FES, under the partial sponsorship of the Water Quality
Office, Environmental Protection Agency.
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CONTENTS
Section Page
I. Conclusions 1
II. Recommendations 3
III. Introduction 5
IV. Experimental Plan and Equipment 13
Modifications to Existing Equipment 13
Dirt and Grit Removal 17
Incineration 17
Pulverization 18
Paper Machine Trial 19
Printing Trials 19
V. Results and Discussion 21
VI. Full Scale Recovery System 27
VII. Acknowledgements 31
VIII. Glossary 33
IX. Appendices 35
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FIGURES
Page
1. Existing Collection System 15
2. Modified Collection System 16
3. Full Scale Pigment Recovery System 28
VI
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SECTION I
CONCLUSIONS
1. Gritty materials, such as sand, can effectively be
separated from primary treatment sludge through the use of
Bauer type centricleaners provided the sludge is first
diluted to less than 0.75% solids.
2. Sludge at less than 0.75% solids can effectively
be dewatered to 30% solids through the use of a rotary
drum vacuum filter.
3. By carefully controlling both temperature and re-
tention time, a mixed pigment of 84-85% GE brightness and
acceptably low abrasiveness can be obtained through the
thermal incineration of centricleaned dewatered primary
sludge in a rotary kiln.
4. If the temperature in the rotary kiln is allowed
to exceed 1600 F. an excessively abrasive pigment will
be obtained which is not suitable for use in the paper-
making process.
5. Grinding and classifying in a Bauer Pulverizer-
Classifier produces a pigment of acceptable particle size
for use in the papermaking process.
6. Reuse of the reclaimed pigment as a wet end filler
at the paper machines is technically quite feasible.
7. Reuse of the reclaimed pigment as a coating pigment
is not feasible because of the problems associated with
dispersion of the material.
8. Because of the high capital cost involved in the
recovery of this pigment, it is not economically feasible
to use this recovery process at this plant at this time.
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SECTION II
RECOMMENDATIONS
Future work in the area of filler pigment recovery
through the use of incineration techniques should be
discontinued unless more than 40 tons per day of sludge
can be processed.
More effort should be expended to develop an economical
method of either removing the calcium oxide present in
the reclaimed pigment or converting it to calcium carbonate.
If this can be accomplished, the pigment may then possibly
be of more value as a replacement for the more expensive
coating pigments.
Efforts devoted to developing methods of recycling the
sludge without removal of the volatile components, should
be explored moie extensively. The possibility exists
that centriclea^ing sludge may render it suitable for use
in some grades of paper.
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SECTION III
INTRODUCTION
Because of the lack of a better method, numerous in-
dustrial plants are disposing of their dewatered waste
treatment sludges through various landfill operations.
This, unfortunately, is not considered a satisfactory
long term disposal procedure because of the lack of
available land area, the potential air pollution problems
associated with the decomposition of the organic materials
present in the sludges and the potential water pollution
problems which may result from the leaching out of the
sludge piles by surface waters. Consequently, with the
tremendous increase in construction of new treatment
plants throughout the paper industry, it is imperative
that a more suitable sludge disposal method be developed.
This project was geared to accomplish that goal for that
part of the industry which, as a result of its production,
produces waste sludges which have high inorganic pigment
content and relatively low fibrous content. (In general,
a high pigment content sludge is one with more than 25 to
30% pigment.) It can generally be said that most paper
mills producing significant amounts of coated paper or
board will have waste sludges of "high pigment content."
With the assistance of the American Paper Institute it
has been determined that, based on 1968 production figures,
14.5% or 3.2 million tons of the printing papers produced
were coated. In the board industry 4.3% (1.0 million tons)
of the total production was coated. In addition to these
there are also some mills which manufacture high filler
content papers which in some cases would have high ash wastes.
No statistics were obtained on these because of the difficulty
of obtaining grade mix data with which to estimate the
pigment levels in the wastes.
In any event, it can be seen that, with more than nine
percent of the total paper industry producing coated paper
products, there is a widespread need for the development
of a sludge disposal process which will afford an economic
method of recovering the pigment present in that type of waste,
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Background Information
In the early sixties the S. D. Warren Company realized
that it would some day have a problem disposing of the
sludge produced in its primary waste treatment plant.
At that time a thorough literature review was completed
which revealed that dewatered sludge could be disposed
as follows: barging it out to sea since the company is
near the coast, stockpiling it on land, reusing it to make
products such as wallboard, bricks, ceramic building
materials and many other similar products. However, the
general concensus of the literature was that the best
solution to this problem revolved around the removal of
the organic materials present in the dewatered sludge with
the recovery of the ash in a form that is reusable in the
same papermaking process.
Three general methods are potentially available to accomplish
this biodegradation, chemical oxidation or reduction
and pyrolysis. The biodegradation process is not yet well
enough researched to be of practical interest. Oxidation-
reduction processes are basically complex and tend to be
prohibitively expensive. Pyrolysis appeared to be the
method which would afford the simplest and least expensive
alternative to ridding the sludge of the troublesome
organic impurities.
In view of the above, the following course of research was
pursued.
Developmental Research
Developmental research work in the field of sludge in-
cineration began by S. D. Warren in early 1962. At that
time the company did not have a primary treatment system
in actual operation and it was necessary to manually filter
selected waste streams in the mill to obtain the necessary
sludge samples for the incineration studies. The repulping
wash water, which had a flow of 0.76 mgd at a total suspended
solids loading of 66,300 Ibs./day, was filtered with Sweco
screens.
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Samples of the recovered sludge were ashed in a labora-
tory muffle furnace at temperatures ranging from 1290 F.
to 1620 F. The results of these pyrolysis studies were
relatively inconclusive as was indicated by the variability
in brightness of the pigments which were obtained.
Because of the lack of personnel and equipment needed
to obtain large samples of sludge from our wastewaters,
the project was allowed to become dormant until the latter
part of 1965. At that time the company had a 40 foot
diameter Graver clarifier in operation. In general, only
the broke plant waste waters were being included in that
system. Analysis of the clarifier underflow revealed that
the sludge had the following solids composition: 81.7%
clay, 8.0% CaCO.,, 5.0% Ti02' 5.5% organic matter, 0.9%
water soluble salts, and 0.1% Fe 0 .
It was decided to initiate pilot scale field incineration
trials to determine whether or not pigment of acceptable
brightness and abrasiveness could be produced.
First Rotary Kiln Trial
Traylor Engineering, Division of the Fuller Company/General
American Transportation Corporation of Pennsylvania was
equipped with a 12" diameter by 15' long laboratory rotary
kiln which had variable temperature control, variable kiln
slope and speed control. The kiln was also equipped with a
pre-dryer section which had scraper knives to control feed
stock size to the kiln.
Four 55-gallon barrels of 30% solids sludge were shipped
to Traylor Engineering for incineration in their laboratory
kiln in September 1965. The sludge was hand fed into the
pre-dryer section at 431b./hour and thus dried to 70-75%
solids. The kiln temperature was varied from 1500°F. to
1800 F. during the trial. If the temperature was held too
far below 1500 F. the product was greyish in appearance -
presumably because of incomplete combustion of the organic
materials. On the other hand, if the temperature was too
high (1600-1800°F.), although the brightness was excellent,
the product was exceedingly hard and abrasive. The optimum
operating condition was found to be 1500-1550°F. with a 90
minute retention time in the kiln.
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A 500 pound sample of the above calcined material was
sent to the Bauer Brothers Company of Springfield, Ohio
for pulverizing and classifying in their Hurricane
Pulverizer-Classifier. This unit was an air attrition
mill with an integral classifier so that the unit pul-
verizes, classifies, and extracts unwanted impurities.
The results of the pulverizing trials revealed that
pigment with an average particle diameter of 0.54 microns
could be obtained relatively easily and economically.
With an inlet pigment GE brightness of 84.0%, a final
classified pigment GE brightness of 87.0-88.0% was pro-
duced. This, of course, was the result of removing the
coarse low brightness sandy materials present in the
calcined product.
Samples of the calcined, pulverized and classified product
were then evaluated at the S. D. Warren Company Research
Laboratory. Both abrasion tests and hand sheet filler
use tests were run on the recovered product. The pigment
abrasion was tested using the copper disc method and
found to be within acceptable limits although it was
slightly higher than filler clay abrasion values and
about the same as Freeport Kaolin's N-90 calcined clay.
The handsheet tests indicated that the retention of
the recovered pigment in the sheet was the same as regular
pigments. The opacifying properties of the pigment were
equal to N-90 clay and superior to regular filler clay.
Sheet brightnesses were slightly lower than N-90 clay
filled sheets and better than filler clay filled sheets.
Early in 1966 a 180 foot diameter primary clarifier with
15 foot sidewall was constructed. Paper mill wastes were
collected and treated with this equipment. Normal feed
flow is 10 MGD and the .5 MGD of sludge is removed at
2.5-3.0% solids. An existing Impco pulp washer was re-
built for use as a vacuum filter to dewater the clarifier
underflow sludge. Thus, sludge from the primary treatment
system became readily available for succeeding trials.
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Copeland Process Trials
Early in 1968 a sludge incineration trial was run at the
Battelle Memorial Institute facilities in West Jefferson,
Ohio. During this trial the Copeland Process fluo-solids
kiln was utilized. Presumably the combination of vigorous
agitation and mixing of the solids in the fluidized bed
and the enormously large surface area of the bed particles
would contribute to very efficient combustion within the
unit.
The predominant advantage of the fluo-solids incinerator
over the rotary kiln unit is that the calcined pigment
can be recovered as a non-agglomerated fly ash which should
be reusable without further processing.
Seventeen 55-gallon drums of 30% solids dewatered clarifier
underflow were shipped to Battelle for incineration. A
number of mechanical and operational problems were encountered
with feeding the sludge into the incinerator. However, most
of these problems were corrected and the sludge was calcined
at 1300-1750°F. and samples of both the fly-ash and bed
products were obtained after quasi-steady state was achieved.
For the most part the samples obtained at the lower tempera-
tures were quite greyish colored and somewhat abrasive. The
samples obtained at the higher temperatures were more deeply
beige colored and appreciably more abrasive.
The fly ash product obtained during this trial was generally
less than 110 mesh particle size and of relatively high
brightness (78.6% GE). However, the abrasiveness of this
product was 60% higher than the bed product obtained at
the same conditions. Presumably this was the result of
carry over of sand from the bed into the fly ash product.
(The trial was started with a sand bed with the thought
that as the trial progressed the sandy material would be
displaced by agglomerated calcined pigment. Unfortunately,
this phase of the trial was never completed because of the
long times required to replace the bed.)
Samples of the pigment obtained from the bed product were
used in handsheet studies at the S. D. Warren Company
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laboratories. After grinding and screening it was found
that a significant amount of grit and silica was collected
on 80, 120, 200, and 325 mesh screens. This may have been
due to the original sand bed present in the system. Evi-
dently the calcined pigment agglomerated around the sand
particles. The sand was then separated from the clay during
pulverizing.
Handsheets prepared with this filler material were generally
of lower optical qualities than either conventional filler
clay filled sheets or those filled with the pigment which
was recovered during the earlier rotary kiln trial.
In view of the high abrasiveness of the pigment obtained
during the above trial it was then decided to examine the
effects of abrasive materials present in the treatment
system before incineration on the final abrasiveness of
the recovered product. Samples of sludge were obtained both
with and without inclusion of the debarking operation
waste (high sand content). These samples were then incin-
erated in a laboratory muffle furnace at 1000 F. After
calcining and grinding the pigment abrasiveness of each
was determined. It was found that the calcined pigment
with the debarker waste included was 70% more abrasive than
that without the debarker waste.
After having determined that the calcined pigment abra-
siveness might well be partly due to the sandy materials
present in the waste, a repeat incineration trial using
the Copeland Process system was initiated. In this case,
however, the sludge was obtained during a period during
which no debarker waste was being added to the treatment
system.
As an integral part of this trial, differential thermal
analyses (DTA) were run on dried sludge and normal clay
filler. The results of these analyses indicate that al-
terations in the physical properties of clay (e.g., abra-
siveness) may occur at 1110°F. and 1960°F. It was then
decided to calcine the sludge between 1280°F. and 1580°F.
and vary the fly ash recycle rate and thereby effectively
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control the retention time in the incineration zone of
the unit.
Unfortunately, the results of this trial were virtually
the same as those obtained during the first fluo-solids
incineration trial reported above. The brightness was
relatively low despite the increased recycling and the
pigment abrasiveness was again quite high, presumably
because of sand carry over into the fly ash product.
Second Rotary Kiln Trial
In order to determine whether or not the results obtained
in the Traylor Engineering rotary kiln trial of 1965 were
applicable to the incineration trials on the sludge obtained
from the installed primary treatment system, a repeat trial
was run in early 1969. In this case, sludge from the entire
primary treatment system was used instead of from just the
broke plant. The incineration conditions were the same
as those of the previous trial. The temperature was again
kept below 1600 F. with a retention time in the unit of
65 minutes. The product which was obtained was in pellet
form and of very high brightness.
Samples of the pellets were again sent to Bauer Brothers
for pulverizing and classifying in their pilot unit.
After pulverizing, a 100 pound sample was sent to the
S. D. Warren Company for further evaluations.
Pigment brightness measurements on the recovered pigment
indicated that a very good product had been obtained.
(GE brightness = 86.5%). Handsheet furnish studies re-
vealed that the pigment had superior optical properties
to filler clay and retention properties which were as
good as normal filler clay. Unfortunately, the abrasive
properties were again considerably higher than desired.
In order to resolve the abrasiveness problem, samples
of isolated broke plant waste and clarifier sludge were
dewatered and calcined at 1500 F. in a muffle furnace for
2 1/2 hours. The abrasiveness of each recovered sample
was then measured as before. The clarifier sample was
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again found to be about twice as abrasive as the broke
plant sample. The most probable reason for this increase
is that the clarifier sample has other sandy type wastes
included in the sludge. These gritty materials of course
contribute very significantly to the abrasive problem.
In order to complete the research program it was proposed
that more extensive incineration trials be run on the de-
watered sludge produced in the primary treatment system.
Two important additional considerations would be made.
(1) Primary clarifier sludge would be degritted prior to
incineration in an effort to decrease the abrasiveness
problem and (2) the quantity of recovered pigment produced
should be great enough for use in a full scale papermaking
trial.
Thus it was proposed that a mill scale pilot run be
organized to solve remaining technical problems and
determine the technical and economic feasibility of the
process.
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SECTION IV
EXPERIMENTAL PLAN AND EQUIPMENT
Based upon the knowledge and experience gained through
research in the preceeding years, an experimental plan
was developed which would lead to the production of
usable pigment from primary clarifier sludge. The
necessity of degritting sludge prior to incineration had
been satisfactorily shown in the laboratory, although
never tried on the pilot scale. Only limited amounts of
recovered pigment, enough for handsheet analysis, had been
obtained. It was desired to produce a quantity of pigment
great enough to allow its use in a full scale paper machine
trial.
Accomplishing the objective of producing usable pigment,
in quantity, from primary clarifier sludge required that
modifications be made to existing S. D. Warren equipment,
and pilot scale equipment be contracted from outside for
certain special work.
Basically the experimental plan consisted of the following
steps. (1) Obtain sludge free from the dirt and grit that
caused part of the previous abrasiveness problems. (2)
Incinerate the degritted sludge to remove unwanted organics.
(3) Pulverize the incinerated sludge to produce a uniform,
fine particle size. (4) Run a full scale paper machine trial
using the recovered pigment in place of virgin filler. (5)
Print the paper produced as a final test of the papers
quality. Naturally evaluations were to be undertaken after
each step to determine the product quality before continuing
the work.
Each of these phases was indeed completed. Detailed in-
formation explaining the equipment and methodology involved
in executing each step is presented forthwith.
Modifications to Existing Equipment
Before discussing the modifications incorporated for this
project a brief explanation of the existing sludge collec-
tion and dewatering system is in order.
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Waste waters are collected throughout the paper mill
and pumped to a 180 foot diameter primary clarifier.
At 10 MGD flow the detention time is about 7 hours
and the overflow rate 400 gal/day/sq.ft. Influent
pH varies from 6.0 to 10.0 and effluent pH from 6.5
to 7.5. Temperature varies with seasons of the year
from influent values of 60° to 80°F. and effluents
from 35° to 90°F. Influent BOD ranges from 200 to
300 mg/1 and is reduced to 100 to 150 mg/1 in the
effluent for a 35 to 50% reduction. Suspended solids
are reduced 75% from an average influent of 3000 mg/1
to 750 mg/1. Complete removal (100%) of fiber and
settleable solids is achieved.
Underflow sludge at 2.5-3.0% solids is pumped to a
9000 gallon surge chest located in the mill. Sludge
is then pumped from the surge chest with a centrifugal
pump, to an 8' diameter x 10' face rotary drum vacuum
filter. A flocculation agent, Calgon WT 2660 (a cationic
polymer) is injected just prior to the vacuum filter to
aid coagulation and the dewatered sludge comes off at
25-30% solids. Sludge is conveyed to trucks for disposal
as land fill. Figure one is a schematic of the existing
system.
The first objective to be met for the mill scale trial
was the production of dewatered sludge free from abra-
sive materials such as sand and gravel. Two alterna-
tives were available to accomplish this end. (1) A
grit removal system could be installed on mill wastes
ahead of the clarifier to remove abrasive materials
or (2) a portion of the under flow sludge at 2.5-3.0% could
be diluted to 0.5-1.0% and centricleaned. After con-
siderable analysis it was decided that a sludge dilution
and centricleaner system would prove most feasible to
provide the amount of degritted sludge required for this
pilot project. Economics and ease of operation were the
determining factors.
Modifications necessary to incorporate the degritting
equipment were minimal. The existing system was changed
as follows: 1. The 2.5-3.0% solids sludge from the
primary clarifier was diluted with fresh water to obtain
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Q
MOYNO PUMP
SURGE CHEST
PRIMARY CLARIFIER
CENTRIFUGAL
PUMP
MILL COLLECTION
STATIONS
VACUUM FILTER
POLYMER
INJECTION
TO LAND FILL
FIGURE 1
EXISTING COLLECTION SYSTEM
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PRIMARY CLARIFIER
MILL COLLECTION
STATIONS
MOYNO PUMP
TRASH PUMP
SURGE CHEST
VACUUM FILTER
V
CENTRICLEANER
POLYMER
INJ ECTION
TO COLLECTION
CENTRIFUGAL
PUMP
FIGURE 2
MODIFIED COLLECTION SYSTEM
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0.5-1.0% solids sludge in the surge chest, the surge
chest being used as a dilution tank. Consistencies in
this range are necessary to enable the centricleaner
to operate at maximum efficiency. It was necessary to
run a fresh water line to the surge chest. 2. A
6" x 6" Gorman-Rupp sludge pump was procured and installed
for series operation with the existing centrifugal pump
located between the surge chest and vacuum filter. The
additional pump was required to overcome the 40 psig
pressure drop imposed by the Centricleaner. 3. A Bauer
Brothers Model 606-110P Centricleaner was installed after
the new pump and prior to the vacuum filter to remove the
abrasive sand and gravel. Figure two is a schematic
showing the location of the pieces of equipment that were
incorporated. The interrelationship and operation of
these pieces of equipment is described in the next section.
Dirt and Grit Removal
Primary clarifier sludge was diluted with fresh water from
2.5-3.0% solids to 0.4-0.7% solids in the surge chest.
Because of our particular situation and the economics in-
volved a batchwise operation was required.
Diluted sludge was pumped, using two centrifugal pumps
in series, to the Bauer Centricleaner. Accepts were
diverted to waste until a flow of 100 gpm at 37-40 psig
was attained. Centricleaner discharge was submerged.
Accepts were then valved to the vacuum filter headbox.
Flocculating polymer was injected between the centri-
cleaner and vacuum filter to aid in dewatering.
Vacuum filtration was accomplished with a vacuum of 9-10
inches of mercury at a drum speed of about 5.2 revolutions
per hour. The degritted sludge was dewatered to 25-30%
solids.
The sludge blanket, or cake, was discharged via a screw
conveyor into polyethylene lined 55 gallon drums. A
small amount of formaldelhyde was added to each drum to
prevent bacterial decomposition and the liners tied off.
Drums were fitted with covers for shipment.
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Data was collected throughout the grit removal and
collection period. Log sheets were maintained to
monitor routine operating conditions such as sludge
flow rate, pressure drop across centricleaner, reject
flow rate, drum vacuum and surge chest level.
Samples were obtained of feed and centricleaner accepts
and rejects for analysis. No operational problems were
encountered during this work. , '
Incineration
Incineration of degritted sludge was contracted to the
Fuller Company, a Division of General American Trans-
portation Corporation (GATX) in Catasauqua, Pennsylvania.
As previously noted, the Fuller Company had some experience
with S. D. Warren sludge.
The equipment used in this program was a 3' x 30' rotary
kiln lined with 70% alumina brick, 4 1/2" thick. It
has a variable speed range between 0.8 and 4.2 RPM and a
slope control between horizontal and 3/4" per foot.
The exhaust end gases of the kiln pass through a brick
fall put chamber and then to a bag collector or to
atmosphere when using natural draft. Temperatures in the
kiln hot zone were measured optically and by direct ther-
mocouple probes within the load. View ports were located
in the firing hood. The kiln was fired with #2 fuel oil.
Sludge was shredded in a pug mill prior to incineration.
The pug mill used in this program was an 8' long unit
with variable spe<=>d drive. It consisted of a single
shaft chopping blade arrangement with additional blades
added to the last 3' of the unit to insure satisfactory
shredding. The pug mill was hand fed from the drums
for this test.
The Fuller Company kept complete records and reported
results to the S. D. Warren Company. No functional or
mechanical ...operational problems were encountered with
this equipment.
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Pulverization
Pulverization of degritted, incinerated sludge was con-
tracted to the Bauer Brothers Company a subsidiary of
Combustion Engineering, Inc., located in Springfield, Ohio.
A Hurricane Pulverizer-Classifier was used to grind the
sludge fine enough so that 99.9% of the particles would
pass through a 325 mesh screen. It was set with 24
fingers (rotary arms which flail the incoming pigment
agglomerates and thereby reduce their size) in the
classifier. A reject rate of 3-5% was set. Two angle
iron deflectors were used on the classifier shelf.
!
Bauer Brothers Company kept complete records and re-
ported results to the S. D. Warren Company. No functional
or mechanical operational problems were encountered with
the Pulverizer-Classifier.
Paper Machine Trial
Degritted, incinerated, pulverized primary clarifier
sludge was utilized as the filler pigment in a full scale
paper machine trial. S. D. Warren's Number Eight Paper
Machine was utilized. It is a typical Fourdrinier with a
size press and MF (machine finish) stack. This machine
is capable of producing paper 57 inches wide at a rate
of 340 feet per minute. It normally produces thirteen
tons per day.
The paper, Publisher's English Finish Offset, was made
in three basis weights, 45 pound, 50 pound, and 70 pound
(per 3300 ft2). No mechanical problems were encountered
with the paper machine while producing paper utilizing
the recovered' pigment as 'filler. '
Printing Trials
Paper produced utilizing recovered pigment as filler was
print tested on commercial presses.
Livermore and Knight Company, commercial printers located
in Providence, Rhode Island, printed 1000 sheets of 50
pound (per 3300 ft2) Demonstration Grant paper. The paper
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had been cut to sheet dimensions of 52" x 76" (the
largest sheet size normally printed). Two presses
were utilized. One side was printed on a 77" Miehle
offset press in two-color (black and green) at 4000
impressions per hour. Twenty four hours later the other
side was printed on a 77" Harris four-color press at a
rate of 2300 impressions per hours.
The Print Testing Department of the S. D. Warren Company
printed 30,000 sheets with black ink on both sides. A
26" Harris offset press was utilized.
No mechanical problems were encountered using Demonstra-
tion Grant paper on any of the three commercial printing
presses.
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SECTION V
RESULTS AND DISCUSSION
Evaluations were conducted during and at the completion
of each of the experimental phases previously discussed.
During the sludge dilution, degritting and dewatering
phase samples were obtained for analysis so that sludge
quality could be determined. S. D. Warren Research Lab-
oratory personnel performed the testing. No sand or
grit was found in any of the centricleaner accepts samples
under visual microscopic observation at 20 power or by
photomicroscopy at 45 power. Results of quantitative '
analysis of Batch Number Eight and additional details may
be found by referring to Appendix A "Clarifier Sludge
Trial Solids Analysis." This batch was representative
of the trial. Laboratory report "Abrasion Tests of
Calcined Sludge" included as Appendix "B" compares results
obtained from calcined sludge with the Hi Opaque clay
normally used in the papermaking process. The abrasiveness
of sludge dried and calcined (incinerated) in the laboratory
at 1500°F. was obtained after the sludge recovery trial and
before calcining by the Fuller Company. The value, .0178,
was satisfactory.
Since these evaluations showed the degritted sludge to be
acceptable, 30,000 pounds were shipped to the Fuller Company
for incineration. Incineration was done in the Fuller
Company's pilot 3' x 30' rotary kiln. The incineration
was to be accomplished at 1500 F.-1600 F. However, the
Fuller Company, in an effort to improve brightness charac-
teristics, and without consulting S. D. Warren personnel,
increased the calcination temperature to 1900°F.-2100°F.
The resulting product was very abrasive in nature. Upon
learning that the Fuller Company had calcined at 1900°F.,
S. D. Warren personnel calcined at 1900°F. under controlled
laboratory conditions. This was done so that a determina-
tion of the effects of temperature on the abrasive quality
could again be obtained. The results are in Appendix B and
21
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show that calcining at higher temperature^causes abra-
sion to be 2.71 times as great as at 1500 F. The test
of the Fuller calcined clay showed it to be 3.56 times
as abrasive.
An additional problem was also encountered. Although
the original proposal was to recover three tons of
pigment, only one ton of product was obtained. This was
due to the fact that the LOI (loss on ignition) was higher
than expected and because dust losses were considerably
higher than anticipated in the range of 30 percent.
Procedures followed during the incineration trial, details
of operation, results and conclusions are presented in
Appendix C. This work was done by the Research Department
of the Fuller Company. Although it was realized that the
calcined product was too abrasive, hope was sustained that
pulverizing would improve this characteristic.
Degritted, incinerated sludge was pulverized with a Bauer
Brothers Hurricane Pulverizer-Classifier. This operation
was successful from an operational standpoint, however
the abrasiveness was improved only slightly, and not to
a satisfactory level.
Appendix D, "Hurricane Milling of Calcined Sludge," defines
the operating conditions and conclusions of the pulveriza-
tion trial. Brightness of the product was satisfactory at
81-82. Evaluations of the experimental work completed to
this point showed that the quality of the product obtained
was not satisfactory for use in a paper machine trial because
of high abrasiveness. This was a very regrettable circum-
stance, because the process otherwise looked very promising.
The cause of the high abrasiveness was traced directly to
incineration at too high a temperature. Discussions were
held with the Fuller Company and it was determined that,
with minimal modifications the incineration could indeed
be done at 1500°F.
Because of our desire to continue this project to comple-
tion, and armed with information that pinpointed the cause
22
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of the problem encountered, and a solution to that problem,
it was decided to repeat the work done to date.
Therefore more sludge was degritted, dewatered and
barreled for shipment and 65,500 pounds were shipped for
incineration so that a greater quantity of product could
be obtained.
The incineration trial was modified in the following
manner: Two passes through the 3' x 30' rotary kiln
were utilized. The first pass was at low temperature
(1200°F.) and high feed rate to pre-dry the sludge. The
second pass was at 1500°F. and a low feed rate to accomplish
the incineration.
The incineration portion of this trial was witnessed by
a representative of the S. D. Warren Company who performed
abrasion tests at the site during the trial. The on site
abrasion testing enabled Fuller Company personnel to adjust
kiln operating conditions so that a product of acceptable
abrasiveness, while maintaining brightness, could be obtained,
Actual results of the abrasion tests can be found in Appendix
E. Details of the rotary kiln operating conditions during
the second drying and incineration entitled "Paper Mill
Sludge Calcination" is included as Appendix F.
Calcination was again followed by pulverizing in the
Bauer Brothers Hurricane Pulverizer-Classifier. A report
of this work is included here as Appendix G. It should
be noted that a Fisher particle size averaging 0.83 microns
was obtained. This indicates a product of low abrasiveness.
Evaluation of the second calcination product at S. D. Warren
showed an abrasiveness of .0185 and brightness of 83-84, both
of which are acceptable.
Degritted, calcined, pulverized sludge was evaluated by the
Research Laboratory to determine whether it should be used
as a filler pigment or in a coating application. Appendix
H "Evaluation of Calcined Sludge as a Filler Pigment" con-
cludes that the pigment appears to have desirable properties
23
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as a filler pigment. Dirt was found to be at a minimum
and abrasiveness and brightness were acceptable. Chemical
assay showed the following composition; 14.3% as CaO, 9.2%
as TiO and 76.5% clay. Analysis was done in accordance
with TAPPI suggested method T673, Quantitative Determina-
tion of Mineral Filler and Mineral Coating of Paper, Vol. 49,
No. 11, November 1966.
Difficulty was experienced utilizing the calcined sludge
for use in blade coating applications. Results utilizing
sludge for this purpose were only moderately encouraging.
In addition the sludge was tried as a coating pigment for
conversion coated grades of paper. It was concluded that
coatings containing sludge pigment show lower brightness
and gloss values than normal coating pigments. High pH
levels in coating slurrys also presented problems. The
recommendation was that other uses for calcined sludge
be explored.
It was decided that the pigment recovered from the in-
cineration of degritted primary clarifier sludge would be
used as a filler pigment in a full scale paper machine
trial.
No serious "runnability" problems were encountered during
the trial although high alkalinity caused poor retention.
S. D. Warren print test results for all basis weights were
rated as "FAIR", on a scale extending from POOR, FAIR-,
FAIR, FAIR+, GOOD. Thus it was felt that the paper was
shippable as first quality. The paper produced. Publisher's
English Offset Finish, met at least minimum specifications
in all tests required for that paper. "Demonstration Grant -
Paper Machine Trial" a report documenting general trial
procedures, paper testing criteria, results and conclusions
is included here as Appendix I. Specific test results of
the paper's physical and printing characteristics in com-
parison to a blank,, of normally produced paper, are summarized.
The paper produced using recovered pigment as filler was
print tested by Livermore and Knight, commercial printers
24
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located in Providence, Rhode Island. The four-color
offset print trial of 50 pound paper (3300 ft2) was a
success with no problems encountered. S. D. Warren print
testing department printed the 70 pound paper in a full
scale test. The sheets delivered a good flat load with
ink drying and binding to the surface very well. The
paper performed well during the test and also in a later
bindery operation. Appendix J summarizes the results of
the "Print Trial - Demonstration Grant."
Thus it has been shown that S. D. Warren primary clarifier
underflow sludge can be successfully degritted, incinerated,
and pulverized. The resulting pigment can be introduced
back into the papermaking process and incoroorated as a
filler material. The paper produced will meet at least
minimum specifications for certain grades of paper and
perform well under commercial printing conditions.
25
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SECTION VI
FULL SCALE RECOVERY SYSTEM
If a full scale pigment recovery system were built
at this plant it would be sized to process 40 tons
per day (dry basis) of primary treatment sludge which
would be dewatered to 30% solids.
Based on the results of this study such a system would
consist basically of a sludge degritting system, a sludge
shredder, a rotary kiln, a pigment pulverizer-classifier
and a pigment storage and distribution system. (See
Figure 3 for a schematic of such a system.)
The basic equipment breakdown would be as follows:
1 - 10,000 gallon sludge dilution tank
1 - Sludge solids controller
18 - Centricleaners sized to handle 2.5 MGD @ 0.5% solids
2 - Vacuum filters
1 - Sludge shredder
1 - Rotary kiln 6' 6" x 160' long
1 - 50,000 gallon oil storage tank and distribution system
1 - Pulverizer-Classifier sized to handle one ton per
hour feed
1 - 80 ton per day bulk storage system
1 - Slurry tank
All necessary conveyors, instrumentation, buildings, etc.
The system described has been estimated to cost approxi-
mately $1,500,000 with an annual operating cost in the
neighborhood of $175,000 per year. (See cost estimate
included in Appendix K for details.)
On a production basis of 24 hours per day, 360 days per
year and at a rate of 7,500 tons per year of recoverable
pigment the estimated cost of the recovered pigment would
be $71 per ton. However, part of this cost would be de-
frayed because of the savings associated with elimination
27
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00
FULL SCALE PIGMENT RECOVERY SYSTEM
POLYMER
INJECTION
SLUDGE
2.5% SOLIDS
CENTRICLEANERS
CONSISTENCY
REGULATOR
DILUTION
TANK
REJECTS TO
SECONDARY TREATMENT
PULVERIZER
CLASSIFIER
2.2 MGD
FILTRATE TO
SECONDARY
TREATMENT
DILUTION
WATER
i
j
BULK
STORAGE
I
SLURRY
TANK
FIGURE 3
-------
of the present method of sludge disposal. This would
amount to approximately $21 per ton saving or effectively
a $50 per ton cost for the recovered pigment.
Since the delivered cost of virgin filler pigment is $38
per ton, it is readily apparent that recovery of the same
quality pigment at $50 per ton is not economical.
However, the concept of full scale pigment recovery should
not be discarded because of the potential value of this
pigment as a replacement for some of the more expensive
coating pigments. Admittedly, the results of the labora-
tory evaluations on the pigment reclaimed during this trial
were not very encouraging. Nevertheless, it should be
pointed out that it may be possible to either re-precipitate
the troublesome calcium oxide present in the pigment or to
remove the calcium oxide by washing with clean water. In
either case the product that would result may well be of
use as a coating pigment of higher value and a full scale
pigment recovery system of this type would then become more
economical.
29
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SECTION VII
ACKNOWLEDGEMENTS
The Project Director, Dr. Richard P. Labrecque, wishes
to acknowledge the assistance received from the following
S. D. Warren Company personnel:
Mr. L. B. Abbiati and Mr. W. Van Voorhis for their per-
mission to undertake this program as well as their manage-
ment guidance during the course of the study.
Dr. N. J. Lardieri, Dr. J. H. Vreeland, Dr. D. H. Juers,
and Mr. R. G. Knox for their technical guidance and
accounting services during the program.
Mr. C. N. Loveland and Mr. B. A. Bittner and their staffs
for construction of the necessary facilities.
The technical assistance received from the several Research
Laboratory, Technical Department, Paper Machine, Print
Testing, and Environmental Improvement Department personnel.
In particular the assistance of M. L. Jewell, R. A. Parmenter,
N. A. Russell, E. Flaherty, and T. E. Weymouth is gratefully
acknowledged.
The secretarial assistance contributed by Mrs. J. Sanford
is gratefully acknowledged.
The help of the personnel of the Traylor Engineering
Company, the Bauer Brothers Company and the Livermore and
Knight printing plant is acknowledged.
The support of the project by the Federal Wpter Quality
Office of the Environmental Protection Agency and the
particular help provided by Mr. William Lacy,
Mr. George Webster, and Dr. Hend Gorchev, the Grant Pro-
ject Officer is acknowledged with sincere thanks.
31
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SECTION VIII
GLOSSARY
Abrasive - degree to which a substance would cause
wearing by friction.
Accepts - product reclaimed, as opposed to rejects.
Broke - repulped waste process paper.
Calcine - to heat to a high temperature but without
fusing in order to effect useful changes.
Centricleaner - device which utilizes centrifugal force
to separate undesirable particles such as sand.
Coating Pigment - a pigment suitable for addition
principally to the surface of paper.
Deqrit - remove unwanted abrasive components.
Dewater - to remove excess water leaving solids.
Filler Pigment - a pigment added throughout the internal
paper structure.
Flocculating Polymer - chemicals which will cause particles
to agglomerate.
GE Brightness - (General Electric brightness) measure of
reflective properties.
Incinerate - burn to ashes,"i.e. removal of organics.
Loss on Ignition - (LOI) weight of a substance lost during
incineration.
Pulverize - to reduce to very small particles.
33
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Rotary Kiln - heated enclosure, revolving on its axis,
used for processing a substance by burning.
Runnability - capability of the paper machine to
continuously run paper of acceptable quality.
Solids Content - matter remaining after removal of the
liquid phase of a solution.
34
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SECTION IX
APPENDICES
Page No.
A. Clarifier Sludge Trial Solids Analysis . . 37
B. Abrasion Tests of Calcined Sludge 43
C. Paper Mill Sludge Calcination 45
D. Hurricane Milling of Calcined Sludge ... 57
E. Results of Abrasion Tests Done at the
Fuller Company 61
F. Paper Mill Sludge Calcination 63
G. Hurricane Milling of Calcined Sludge ... 73
H. Evaluation of Calcined Sludge as a Filler . 77
I. Demonstration Grant - Paper Machine Trial . 81
J. Print Trial - Demonstration Grant 87
K. Full Scale System 89
35
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APPENDIX A
CLARIFIER SLUDGE TRIAL SOLIDS ANALYSIS
A request was submitted to analyze clarifier sludge solids
and coordinate other research activity as abrasion testing
and photo documentation. "Feed" samples directly from the
clarifier and "accepts" versus "rejects" samples from trials
using a Bauer Centricleaner were submitted to determine
differences in solids. Differences were determined by
screening, filtration, microscopic examination and chemical
examination. Identification of particles with particular
emphasis on grit or sand particles was carried out.
Summa ry
No hard grit and/or sand was detected in any of the sub-
mitted samples.
The Bauer Centricleaner appeared to separate on the basis
of particle size rejecting the larger particles of a given
trial as opposed to separating on the basis of mass.
Retained, screened material was primarily fiber and coating
chips. Black and brown specks, etc. were a minimal fraction.
More black and brown specks or grains were noted in the
"rejects" samples than in the "feed" or "accepts" samples.
Upon examination, the black and brown specks or grains
proved to be oil, grease, tar, coal, bark, melamine-like
resin, leafs, tobacco, and other particles that would
powder or break easily as compared to sand,
Coating chips were present in three forms: hard platelets
of varied sizes, in a semi-gelled state and in a complete
gelled state. Treating these materials with HCl caused
disintegration and CC>2 evolution.
One sludge trial was measured quantitatively for sieve
sizing, total and suspended solids, ash, Ti02 and CaCC>3.
Photomicrographs were taken of the screened samples to
document the visual data.
37
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A composite sampling of all the trials showed a similar
distribution of fiber, coating chips, black and brown
particles and gelled coating as the above trials.
Discussion
The first trial of September 23, 1970 consisted of samples
from the Bauer Centricleaner using various discharges to
determine best operation method for this device. 80, 120,
200, and 325 mesh screens were used in a stack to separate
100 mis. of starting sample. In turn, these separates were
examined using 15X microscopy:
Submerged discharge with 4 psi backpressure
Feed sample - Mainly fiber mass with few coating
chips. 325 screen was plugged with
small fiber ends, vessels and coating
gel. Very few black or borwn specks
noted.
Accepts sample - A large presence of fiber with few
coating chips on 325 screen. Very
few other specks noted.
Rejects sample - An abundance of fiber with coating
chips. Also presence of black and
brown specks of leaves and tar-like
substance.
Submerged discharge
Feed sample - A fiber mass with coating chips sus-
pended within. Some large black
particle-like grease. 325 screen
plugged with fiber ends, vessels
and coating gel.
Accepts sample - A fair amount of fiber with some brown
leaf-like material. 325 screen had
slight fiber and coating presence'.
Rejects sample - Large quantity of fiber with coating
chips being suspended within. Also
black and brown specks seen through-
out suspension.
38
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Free fall discharge
Feed sample
Accepts sample
Rejects sample
- Some fiber mass with few coating
chips and splinters. 325 screen
had little fiber and coating gel.
A fiber mass with a few brown leaf-
like specks. 325 screen had fiber
ends and vessels in small quantity.
Abundant fiber and coating chip
presence with some very large black
grains like coal or rust.
None of the above samples showed presence of sand or grit.
This trial shows the influent as a constantly changing media
from the "feed sample" information listed above.
The next trial of September 25, 1970 was B-8 (batch 8}
samples taken at 4:00 a.m. These samples were treated
as the previous trial but using 200 mis. of sample. A
quantitative measure of the solids retained on screens,
dried vs. suspended solids and ash with TiO and CaCO
were performed:
B-8 Feed sample - Small quantity of fiber with coat-
ing chips. Few specks but some
large brown resin chunks and black
chunks of grease or oil. 325
screen had short fiber and coating
gel with few specks or coating chips.
B-8 Accepts sample - Fair quantity of fiber with few
specks. 325 screen had short fiber
ends or vessels with few specks.
B-8 Rejects sample -
Large quantity of coating chips sus-
pended in fiber mass. Also large
brown resin chunks and bark presence.
325 screen had small coating chips
in fiber ends with appearance of some
black and brown specks scattered
throughout.
39
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When picked apart, the black specks noted in this trial
appeared as coagulated grease or oil or possibly tar.
Pieces of coal were apparently present also. Photo-
micrographs were made from the screenings.
B-8 Quantitative Compilation
0.1798
0.0053
0.0127
0.1004
0.2982
Feed
Suspended Solids
gms./lOO mis. 0.5304
Retained Screened Solids
gms./lOO mis.
80 mesh
120 mesh
200 mesh
+325 mesh
Total retained solids
Total Dried Solids
gms./lOO mis. , 0
Screened Solids as % of
Total Dried Solids 50
Screened Solubles as % of
Total Dried Solids 49
Ash as % from
Total Dried Solids 50
TiO as % from
Total Dried Solids 5
CaCO as % from
Total Dried Solids 9
Accepts
0.4689
0.1706
0.0026
0.0029
0.0319
0.2080
Rejects
1.2807
1.1881
0.0103
0.0505
0.1884
1.4373
.5950
.10%
.89%
.09%
.49%
.81%
0.5455
38.11%
61.89%
54.12%
5.95%
_
1.9680
73 . 03%
26.97%
50.81%
2 . 64%
11.55%
The above screened samples were retained on filter paper for
photomicroscopy at X45. Since the samples were relatively
large for the 80 and 325 mesh screen sample, a reflected
light source was used here. The 120 and 200 mesh screen
samples were small enough to allow use of transmitted light.
Samples of mill sand, a filter paper blank and a calibration
measure were photographed also.
40
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Upon completion of the sludge trial batch samples were
made into a composite of feed, accepts and rejects. The
composite samples were made from the settled solids thus
eiliminating extra water. Therefore, only a microscopic
examination was performed using 100 mis. of this sample
solution for screening through 80, 200, and 325 mesh sieves
Composite Feed Sample
Composite Accepts Sample
- Primarily fiber with coating
chips suspended throughout.
Some black and few brown specks
being present. 325 screen had
small coating chips with fiber
ends or vessels and few specks
being present.
- Mainly fiber with some coating
chips and few specks noted.
325 screen had coating chips
and gel in some fiber and few
specks.
- Primarily fiber with coating
chips with some black and
brown specks. 325 screen had
coating chips with black and
brown specks.
In this sample series, there were small brown lumps that
would powder like cocoa lumps when pressed. Photomicro-
graphs were made of the above screened separates.
Composite Rejects Sample
41
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APPENDIX B
ABRASION TESTS OF CALCINED SLUDGE
Abrasion tests were run on samples of sludge collected
from the barrels which were shipped to Traylor Company
for calcining.
Abrasiveness was determined by the copper disc method
which is essentially the New Jersey Zinc Company procedure
as derived in Tappi 43 No. 7 230A-232A (July, 1960).
Results
Pigment Loss In Weight of Copper
Disc.
Sludge dried and calcined in Lab
at 1500°F. .0178 grams
Sludge calcined at Traylor 1900 F. .0634 grams
Sludge calcined at Lab at 1900°F. .0482 grams
Hi Opaque clay .0118 grams
Calcining temperature is again found to be critical in
controlling the abrasiveness of the sludge.
43
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APPENDIX C
PAPER MILL SLUDGE CALCINATION
Object
The test described in this report was made for the follow-
ing purposes:
To determine the proper burning conditions and produce a
pigment having maximum brightness and minimum abrasive-
ness .
To produce enough material for the S. D. Warren Company
to evaluate the quality of the product.
To obtain design data.
Introduction
A test program was run on four consecutive days: October 5,
6, 7, and 8, 1970.
Some previous work was performed by the Fuller Research
Department for S. D. Warren Company in April of 1969
and August of 1965 on similar waste sludges to determine
the feasibility of producing a suitable clay pigment.
This program is a scale up similar to the I1 x 12' labora-
tory kiln test made in April of 1969.
Operating Conditions
A pug mill was used in this test program to prepare the
wet feed prior to its entering the kiln. The wet "as
received" feed material fed to the pug mill was in the
form of rolls ranging in size from 6" to 12" long with a
diameter of approximately 3". Some of the rolls were up
to 18" long. The product from the pug mill ranged in
size from 1/4" to 1". The particular high speed shredding
machine that had been considered initially to prepare the
kiln feed was found to be inadequate and tended to pack
and pulp the material.
45
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The kiln slope was kept at 3/8" per foot throughout
the test, and the speeds and retention times used are
listed below:
Kiln R.P.M. Retention Time (Based on the
U.S. Bureau of
1.00 73 Min. Mines standard
1.70 49.5 Min. formula)
1.75 44.5 Min.
1.81 43.2 Min.
The maximum feed rate attained in the test program was
503 lb~s/hr. The indicated fuel consumption is 3.26
million BTU per ton of feed.
Material Tested
On October 1, 1970, 55 gallon drums (32,200 Ibs. gross)
of sludge was received. The drums varied in moisture
from 67.0% to 74.0%.
The feed material was in the form of wet rolls of clay
impregnated paper. The rolls ranged in size from 6" to
1' long and were approximately 3" in diameter; a few of
the rolls were up to 18" long and some were flattened
out by compaction in the drum.
Product Evaluation
No standard equipment was available to detect brightness
or abrasiveness. The products were visually observed
for whiteness and hardness and was judged by rubbing the
material between one's fingers. Bulk densities were taken
on a sample from each drum.
The physical appearance of the product was white to a
yellow tint in color and was relatively soft to the
touch insofar as it would crumble easily when handled.
The individual pieces ranged in size from 3/4 inch to
fines.
The quantity of material sent to S. D. Warren Company
for evaluation was found to be unsatisfactory.
46
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Material Balance
Material In Pounds
Wet feed to kiln 29,240
Product 3,500
Material Out
Kiln product 2,121
Kiln discharge after shut down 164
Kiln drop out material
(222# at 12% H20 and 50% L.O.I.) 97.8
Material recovered from dust collector
and duct work 931
Stack losses when not using dust collector 185
3,498.8
3500 pounds
-3498.8 pounds
1.2 pounds unaccountable
Details of Operation
- The "as received" material was hand fed to the pug mill.
The feed material, which was matted rolls of wet clay
impregnated paper approximately 6" to 1' long by 3" in
diameter, was chopped and shredded down to pieces ranging
in size from 1" to 1/4" pieces. The pug mill discharged
directly into a 5" I.D. feed pipe at the back end of the
kiln. A feed sample was taken from each drum for moisture
and L.O.I, analysis. The kiln discharge was checked
^periodically for whiteness and texture. Each product drum
was sampled for bulk densities and visual inspection.
10-5-70
The test was started using the natural draft system
through the exhaust stack. The run was started with an
47
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approximate feed rate of 460 Ib/hr1 and a kiln speed of
.9 to 1.0 RPM. The hot zone temperature was gradually
increased to 2000°F. and held at this range. After
adjusting temperature and-positioning the burner flame
over the kiln load, a product which contained 3/4"
modules down to fines was produced. The product was
soft and white in color with no dark, cores in the center.
The feed discharge from the pug mill ranged in size from
1" pieces to 1/4" pieces and was fairly steady in rate
of discharge. The 5" dia. feed pipe plugged occasionally;
however, this was eliminated by having an air purge line
with a light flow of air going into the feed pipe. The
material ignited and flamed in the first 12' of the kiln
from the feed end.
10-6-70
At 0800 hrs the kiln speed was increased in order to
reduce the heavy dropout from the back of the kiln. The
kiln speed was gradually increased to 1.70 RPM and the
dropout was all but eliminated. The product was not
affected by the speed change and remained soft and white.
At 1600 hrs the kiln speed was increased to 1.81 RPM and
the feed rate was also increased. These conditions were
held until midnight, at which time it was noticed that
the product color had a yellow tint.
10-7-70
The hot zone temperature was adjusted slightly with no
apparent effect on the yellow tint of the product. It
was also noticed that the free flame zone was slowly
moving forward toward the hot zone. At 0800 hrs the
feed rate was cut back slightly and the kiln speed was
reduced to 1.75 RPM. The product color was slowly im-
proving, however, the free flame zone continued to move
forward. With the pressure drop across the exhaust system
gradually increasing, it was decided to exhaust through
the baghouse dust collector. By 1230 hrs the system was
switched over. The kiln speed was reduced to 1.70 RPM,
the free flame zone was moving back and the product was
losing the yellow tint. This was continued until mid-
night. The product was white and soft throughout
this period.
48
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10-8-70
The dust collector was not functioning properly, and at
midnight the system was again switched over to natural
draft. The dropout material from the previous days
running was returned as feed. The product from this
material had a yellow tint to it also. At 0530 hrs the
feed was exhausted and the test terminated.
Heat Balance
Theoretical
Heat required to evaporated water:
(70%) (503Lb/hr.) (1122 BTU/Lb.)
394,944 BTU/hr. = 1.535 M. BTU/
ton Feed
Heat required to raise solids to temperature:
(151Lb solids/hr.) (0.25) (1950.70)
71,440 BTU/hr. = 0.283 M. BTU/
ton Feed
Required heat assuming no heat recovery
from the internal carbon = 1.818 M. BTU/
ton Feed
Efficiency of the kiln is 40% =
Input required = ±7^ = 4.52 M. BTU/
u ton Feed
Heat from the internal carbon:
(151Lb dry solids)(15%C) = 22.7 LbC/hr. _ i 26 M
(22.7LbC/hr.)(14000 BTU/Lb.) =320,000 BTU/hr. BTU/ton
Feed
4.52 M. BTU/ton Feed - 1.26 M. BTU/ton Feed =
Required Heat = 3.26 M. BTU/ton Feed
49
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Experimental
Peed = 503 Lb/hr.
Average fuel per hour = 11.8 gal. = 1.54 M. BTU/hr.
Fuel consumption per ton of feed =
(1.54) (2|22) = 5.98 M. HTU/ton Feed
Scale up factor for commercial kilns = 1.95
5.98 M. BTUAr. = mu/tan Feed
1.95 Factor
Equipment
Equipment in this test program consisted of the following:
Kiln
The 3' x 30' Kiln is lined with 70% alumina brick 4 1/2
inches thick. It has a variable speed range between 0.8
and 4.2 RPM and a slope control between horizontal and
3/4" per ft. The exhaust end of the kiln passes through
a brick fallout chamber, and then can either go to a bag
collector or to atmosphere through a natural draft system.
Temperatures in the kiln hot zone are measured optically
and temperatures at the feed end of the kiln are measured
with a thermocouple. Viewports are located in the firing
hood. The kiln is oil fired (#2 fuel oil). The kiln
was fed with a pug mill.
Pug Mill
The pug mill is an 8' long unit with variable speed
drive. It consists of a single shaft chopping blade
arrangement. Additional blades were added to the last
3' of the unit for this test to insure satisfactory
shredding of the material.
50
-------
TABLE I
PROPERTIES OF DOMESTIC #2 FUEL OIL
API Gravity No. 33.3
Heating Value: 139,000 Btu's/gallon gross
130,400 Btu's/gallon net
Flash Point 154°F.
Distillation: 10% at 425°F.
50% at 505°F.
90% at 580°F.
End Point 630°F.
Ash 0.001%
CHEMICAL ANALYSES
Carbon 87%
Hydrogen 12.5%
Sulfur 0.5%
Oxygen ° • ^
Nitrogen 0.1%
51
-------
TABLE II
FEED CHARACTERISTICS
Feed
Drum
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Net
Wt.
415
364
459
439
433
435
436
430
432
447
430
430
460
477
477
433
396
442
416
450
469
461
462
451
415
415
456
441
434
440
460
450
Cum.
Wt.
415
779
1238
1677
2110
2545
2981
3411
3843
4290
4720
5150
5610
6087
6554
6987
7383
7825
8241
8691
9160
9521
9983
10434
10849
11264
11710
12151
12585
13025
13485
13935
H2
£.
O/
/c,
mmuJMKb
71
74
68
69
68
69
68
70
68
69
68
69
68
69
72
70
68
69
71
70
71
69
72
69
69
72
71
69
69
71
70
69
0
.0
.20
.98
.43
.34
.13
.69
.95
.54
.75
.72
.59
.66
.40
.90
.07
.90
.08
.12
.17
.26
.87
.01
.37
.03
.24
.16
.38
.78
.89
.23
.73
Dry
Wt.
120
93
142
134
137
134
136
124
135
135
134
130
144
145
129
129
123
136
120
135
134
138
125
138
128
115
131
135
131
123
136
136
LOI
.4
.9
.4
.2
.1
.3
.5
.9
.9
.2
.5
.8
.2
.9
.3
.6
.2
.7
.1
.1
.8
.9
.1
.1
.5
.2
.5
.0
.2
.7
.9
.2
o/
/o
62
62
59
58
57
56
52
61
57
64
56
61
61
65
63
65
62
57
63
61
58
58
62
56
62
68
63
57
58
63
60
64
Potential
Product Cum.
Wt.
.01
.03
.37
.93
.16
.55
.50
.24
.10
.16
.73
.56
.98
.37
.05
.01
.54
.57
.52
.59
.74
.97
.64
.72
.37
.47
.25
.93
.16
.21
.96
.64
45
35
57
55
58
58
64
48
58
48
58
50
54
50
47
45
46
58
43
51
55
57
46
59
48
36
48
56
54
45
53
48
.7
.6
.9
.1
.7
.4
.8
.4
.3
.5
.2
.2
.8
.5
.8
.3
.1
.0
.8
.9
.6
.0
.7
.8
.4
.3
.3
.8
.9
.5
.4
.2
Wt.
81.3
139.2
194.3
253.0
311.4
376.2
424.6
482.9
531.4
589.6
639.8
694.6
745.1
792.9
838.2
884.3
942.3
986.1
1038.0
1093.6
1150.6
1197.3
1257.1
1305.5
1341.8
1390.1
1446.9
1501.8
1547.3
1600.7
1648.9
52
-------
FEED CHARACTERISTICS
(continued)
Feed
Drum
No.
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
Net
Wt.
406
435
434
439
409
380
473
433
347
455
481
434
391
382
426
343
366
393
334
374
426
443
411
436
376
438
373
391
401
426
463
391
Cum.
Wt.
14341
14775
15209
15648
16057
16437
16910
17343
17690
18145
18626
19060
19451
19833
20259
20602
20968
21361
21694
22068
22484
22927
23338
23774
24150
24588
24961
25352
25753
26179
26642
27033
H2°
o/
/o
69.96
69.75
69.96
68.91
71.38
70.02
67.95
68.90
69.15
71.47
72.03
71.05
70.29
67.68
69.02
68.96
68.12
70.25
72.05
67.42
67.85
68.30
68.16
71.54
69.55
69.68
73.14
69.12
70.75
71.94
69.65
69.55
Dry
Wt.
121.9
131.6
130.4
136.5
117.1
113.9
151.6
134.6
107.0
129.8
134.5
125.6
116.2
123.5
131.9
106.5
116.7
116.9
93.4
121.8
136.9
140.4
130.9
124-1
114.5
132.8
100.2
120.7
117.3
119.5
140.5
119.1
LOI
%
65.24
58.03
63.59
61.08
62.37
62.97
62.86
62.29
57.29
67.23
64.26
58.13
64.87
58.77
61.70
59.79
57.61
58-66
60.07
56.05
56.11
56.50
58.62
61.42
55.25
61.87
60.56
57.63
60.34
55.96
57.67
59.35
Potential
Product
Wt.
42.4
55.2
47.5
53.1
44.1
42.2
56.3
50.8
45.7
42.5
48.1
52.6
40.8
50.9
50.5
42.8
49.5
48.3
37.3
53.5
60.1
62.6
54.2
47.9
51.2
50.6
39.5
51.1
46.5
52.6
59.5
48.4
Cum.
Wt.
1691.3
1746.5
1794.0
1847.1
1891.2
1933.4
1989.7
2040.5
2086.2
2128.7
2176.8
2229.4
2270.2
2321.1
2371.6
2414.4
2463.9
2512.2
2549.4
2602.9
2663.0
2725.6
2779.8
2827.7
2878.9
2929.5
2969.0
3020.1
3066.6
3119.2
3178.7
3227.1
53
-------
FEED CHARACTERISTICS
(continued)
Feed
Drum
No.
65
66
67
68
69
70
Net
Wt.
384
399
481
431
411
401
Cum.
Wt.
27417
27816
28297
28728
29139
29540
HO
0^
70.38
68.61
67.47
68.85
71.81
70.86
Dry
Wt.
113.7
125.2
156.4
134.3
115.9
116.9
LOI
o/
/o
55.15
54.45
64.25
62.89
58.01
58.79
Potential
Product
Wt.
51.0
57.0
55.9
49.8
48.7
48.2
Cum.
Wt.
3278.1
3335.1
3391.0
3440.8
3489.5
3537.7
54
-------
TABLE III
PRODUCT BULK DENSITY
Product
Drum No. Date
2 10-5-70
3
4 10-6-71
5
6
7
8
9
10 ..;••-
11 ' 10-7-70
12
13
14
15
16
17
18
19
20 (1st Pt) 10-8-70
20 (2nd Pt)
21
Time
1704-2047 Hr.
2047-0105 "
0105-0454 "
0454-0835 "
0835-1135 "
1135-1515 "
1515-1815 "
1815-2040 "
2040-2315 •''
2315-0150 "
0150-0410 "
0410-0635 "
0635-0905 "
0905-1150 "
1150-1435 "
1435-1740 "
1740-2015 "
2015-2320 "
2320-0200 "
2320-0200 "
0200-0400 "
Bulk
15.7
15.1
15.6
16.0
15.7
16.5
17.2
17.7
15.9
18.3
18.3
17.1
16.9
18.4
16.8
16.8
17.8
13.6
17.3
26.8
21.3
Density
Ib./CF.
II
II
tl
it
ti
M
fl
"
II
II
M
II
II
II
11
It
M
It
II
II
55
-------
APPENDIX D
HURRICANE MILLING OF CALCINED SLUDGE
Material
01 - Calcined sludge - 15 to 24 pounds per cubic foot
and a brightness of 76.4.
Objective
To demonstrate the ability of the Hurricane Pulverizer-
Classifier to grind sludge to 99.9% minus a 325 mesh
screen, and to upgrade by impurity extraction.
Summary &
Conclusions
This calcined sludge was harder to grind than the previous
materials tested.
While no trouble was encountered in grinding to 99.9%,
minus 325 mesh the overall fineness of the material was
not the same. On previous test work an average Fisher
Sub Sieve of .55 to .9.2 Microns was obtained. The lowest
obtainable on this test was 1.5 Microns.
The material was highly contaminated with iron slag, scale
and bolts.
The material had to be run through a magnetic grate to
remove the metal.
If the material had been in better condition a better
overall grinding job would have been done on the pulverizer.
Procedure
The Bauer Model No. 724 Hurricane was uf=ed for grinding and
extracting impurities. The machine set-up is shown on Table
No. I and the Laboratory data is shown on Table No. II.
Water wash screen analyses were taken at 10 pounds of
pressure.
The processed material was sent to S. D. Warren for their
evaluation.
57
-------
TABLE I
October 20, 1970
Run
No.
W-l
W-2
W-3
W-4
W-5
W-6
Run
No.
W-l
W-2
W-3
W-4
W-5
W-6
No. No. No. No.
1234
ROTOR ROTOR ROTOR ROTOR
21" 21" Blank 21"
II 11 M II
II M II II
II II II M
II II II II
H H M II
FRONT BACK SKIM-
DAMPER DAMPER MER
OPENING OPENING OPENING
INCHES INCHES INCHES
1 1 4x2
1 1
1/2 1/2
M H M
" " "
M M II
No.
5
ROTOR
21"
M
1)
II
II
II
FEED
SCREW
PITCH
AND
RATIO
5x4
12:60
II
II
II
II
' II
INNER
DISC.
DIAM.
( INCHES
AND
NO.
5/21
II
II
II
II
II
UPPER
FAN
DIAM.
INCHES
28
II
II
II
II
II
No.
FINGERS
) IN
CLASS-
IFIER
24
It
II
II
11
30
BAFFLE
I.D.
INCHES
18
II
II
II
It
II
NOTES: Two Angle Iron Deflector Added to Classifier Shelf.
58
-------
TABLE II
October 20, 1970
RUN MACH. LBS. TIME LBS/ H.P. STACK
NO. MAT'L. NO. R.P.M. FED (MINS.) HR. USED MANO-
METER.
IN. OF
W-l
W-2
W-3
W-4
W-5
W-6
RUN
NO.
01
II
"
11
11
"
724
11
"
it
11
"
POUNDS
EXTRACTED
3080 95
103
95
" 100
740
881
SPECIFIC
GRAVITY
2.
3.
2.
2.
17.
31.
7
0
7
4
1
0
2100
2060
2100
2400
2600
1710
75 -1
-1
-1
-1
H _ i
66 -2
1/2
1/2
1/2
FISHER % -
PART 1C AL
SIZE
W-l
W-2
W-3
W-4
W-5
W-6
7
7
9
9
6
5
11
11
22
147
13
.7%
.3
.3%
.6
.1%
.8
.0%
.0
.0%
.6%
2.58
II
II
II
II
11
2
1
1
1
1
1
.1
.52
.85
.70
.57
.75
325
MESH
100.0
99.97
99.99
99.99
99.99
99.99
BRIGHTNESS
82.
81.
81.
83.
82.
5
5
0
3
3
120
59
-------
APPENDIX E
RESULTS OF ABRASION TESTS
DONE AT THE FULLER COMPANY
The fuller Company calcined degritted, S. D. Warren
Company sludge on January 6 through 10, 1971. Abra-
siveness tests were performed during the first three
days of the trial to define the kiln conditions under
which a product with acceptable abrasiveness (and
hopefully brightness) characteristics could be obtained.
Abrasiveness was determined by the copper disc method
which is essentially the New Jersey Zinc Company proce-
dure as derived in TAPPI 43 No. 7 230A-232A (July, 1960)
Samples of pigments normally used at the S. D. Warren
Company were taken and the abrasiveness determined
on site so that a direct comparison, under identical
conditions, could be made with the calcined sludge.
Following is a summary of the results of the abrasion
tests. Samples preceeded by a capital S_ are Fuller
incinerated sludge samples. Note that abrasiveness
improved as the trial progressed. High Opaque, Filler
Clay and Albacar are the S. D. Warren samples. The
abrasiveness values on a sample of sludge calcined
and determined in the S. D. Warren laboratory at 1500 F.
averaged .0182.
61
-------
Summary of Abrasion Values
Date
1/6
1/7
1/8
Time
1530
1620
1700
1780
0815
0930
1015
1100
1125
1145
1400
1430
1500
1600
1715
0900
1000
1115
1400
Sample
High Opaque
Filler Clay
S 1400
High Opaque
Albaear
S 0800
S 0700
High Opaque
S 1000
Filler Clay
S 1100
High Opaque
S 1400
S 1400
S 1600
S 0800
Filler Clay
S 1000
S 1200
Abrasion
.0104
.0030
.0365
.0099
.0036
.0435
.0292
.0037
.0328
.0041
.0357
.0090
.0229
.0273
.0213
.0180
.0037
.0208
.0207
Remarks
SDW Lab
SOW Lab
.0118
.0025
Wrinkle in Felt
Torn Felt
Rerun
NOTE: S is for sample, number denotes hour of day obtained.
62
-------
APPENDIX F
PAPER MILL SLUDGE CALCINATION
Object
The_ tests described in this report were made for the
following purposes:
To determine the proper burning condition and produce
a pigment having maximum brightness and minimum abra-
siveness.
To produce enough material for the S. D. Warren Company
to evaluate the quality of the product.
To a limited extent to obtain design data.
Introduction
In the continuing investigation by the S. D. Warren
Company, a fourth series of tests was conducted in the
Fuller Company's Research 3' x 30' rotary kiln on the
calcination of paper plant waste sludge. The previous
work performed by .the Fuller Research Department was
accomplished in August of 1965, April of 1969 and in
November of 1970, on similar waste sludges to determine
the feasibility of producing a useable product from
these waste materials. The last of these tests, in
November of 1970, was conducted in our 3' x 30' rotary
kiln. All tests prior to that time were conducted in
a small I1 x 12' laboratory kiln.
In the latest test it was determined that the excessive
temperature required in the single pass system in order
to obtain the required brightness, produced an abrasive
product which did not meet the requirements for its end
use. In order to produce a quantity of material at the
suitable abrasiveness level, the present test was arranged
for. Since the test prior to the test in November in-
dicated good abrasiveness levels at operating temperatures
in the order of 1500 to 1550°F., it was determined that
this would have to be the limiting temperature for any new
attempts.
63
-------
Based on the last 3' x 30' test where it was determined
that in a single pass system at 1550 F. the required
brightness could not be obtained, it was decided that
in order for this new program to be successful, it would
be necessary to utilize a two-pass system to obtain the
required retention time at the lower temperature. The
first pass was made at a short retention time limiting
the upper temperature to 1200°F. This was done to re-
move the bulk of the water present in the initial feed
material. The second pass would take the product from
the first pass, with its 10 to 20% moisture, and calcine
it at the retention time required at 1500-1550 F. to
obtain the necessary abrasive qualities and whitness.
Recommendations & Conclusions
Based on the information obtained from the test pro-
gram, the following conclusions and recommendations
are made:
As in the last test program using this 3' x 30' kiln,
it was found that a pug mill could be used to prepare
the wet feed prior to entering the kiln. The product
from the pug mill ranged in size from 1/4" to 1" in size.
The kiln slope was kept at 3/8" per foot throughout
the test. The speeds were varied between the drying
phase and the calcining phase with the drying phase
operating at the highest speed and the calcining phase
at the slowest speed.
The drying phase took the 72% moisture sludge down
to under 20% moisture at a temperature of 1200 F. with
a feed rate of approximately 950 Ibs/hr. The indicated
loss of material during this drying stage was approxi-
mately 0.38%.
The physical appearance of the product from the drying
phase was a grayish to black charred surface material
which seemed to be dry, at least on the surface portions.
The recovered material from the drying step contained
an average of 16.6% moisture.
64
-------
The second pass through the kiln gave us an overall
product which met the specifications for abrasiveness
and seemed to have a good brightness appearance to the
naked eye.
The rate fed to the unit during the calcination test
was in the order of 200 Ibs/hr. This material was
determined to have a moisture content on the average
of 16.6% and a loss on ignition on an average of 60.6%.
The calcining tests, due to the re-introduction of a
dry feed to kiln gave a higher loss of material than
indicated in the previous programs. Approximately 40%
of the material was blown out of the test unit, a majority
of which is believed to come immediately from the feed
pipe. Of the material that was lost, about 18.7% was
found in the fallout chamber immediately off the back
end of the kiln and 17.7% was blown through to the ex-
haust stack.
The overall losses during the test as operated, came
to 42.55%. This includes the 40.10% in the calcining
stage and the 2.45% in the drying phase. This figure
is an approximate one due to the errors involved in the
handling and weighing of the material three or four
times during the test.
It is recommended that a system be designed that
would do the required job in a single pass system.
This would require a kiln with a larger length to dia-
meter ratio than found in the 3' x 30' kiln used in this
test program. It is felt that a system utilizing a
single kiln would produce the same quality product as
found by passing the material twice, at a much lower
dust loading.
It is recommended that the dust catches from the system,
which should be less than 30% based on our previous
work, be returned to the pug mill system with the new
wet feed reducing the total moisture content of the
feed and yet allowing the wet material to carry the fine
fraction back into the system.
65
-------
The dust that was caught during the course of the
test program was found to be a partially burnt material,
gray to black in color still containing about 50% of its
initial loss of ignition, but being almost entirely dry.
Material Tested
On December 17, 1970, 140 (55 gallon) drums, having a
gross weight of 66,260 pounds was received. Composite
samples of material taken during the course of the test
program indicated that the moisture levels varied between
70 to 74% moisture. The feed materials were in the
form of wet rolls of clay and laminated paper or fiber.
The rolls ranged in size from 6" to 1' long and were
approximately 3" in diameter. A few other rolls were
up to 18" long and some were flattened out by impaction
in the drums.
Product Evaluation
All evaluation during the course of the test was con-
ducted by the S. D. Warren Company. Evaluations were
primarily a test to determine the abrasiveness of the
end product. As far as the brightness was concerned,
this was visually observed by all parties involved and
the best possible brightness obtained.
Material Balance
Input Pounds
New weight (as received) 62,500
Average moisture 72.7%
New weight (dry basis) 17,062
Average LOI at 1550°F. - 60.6%
Net weight (calcine basis) 6,722
Feed handling losses (450 Ib. gross)
dry basis 5J^
6,671
66
-------
Output Drying Pounds
Drying (Pass No. 1) recovered 19,773.00
Average moisture 16.6%
Recovery dry basis discharge 16,489.68
Shut Down Recovery
After shut down 183 Ib.
Fall out 325 Ib.
Dry basis 423.00
Kiln discharge 16,489.68
Fall out 325.00
Kiln discharge
after shut down 183.00
Total recovered
(Dry Basis) 16,997.68
Unaccounted loss - 17,062.00 - 16,997.68 = 64.32 = 0.38%
Output Calcining Pounds
(second pass)
Total feed to unit 19,773.00
Dry Basis 6,507.03
Recovered Kiln discharge 3,887.00
Shut down material 242.00
Fall out 1,331.00 = 18.7%
Dust collector losses 6507.03 - 5350.00 = 1157.03 = 17.7%
Total loss from production 6507.03 - 3887.00 = 2620.03
= 40.1%
Total Processing Losses
Feed dry basis 6,671.00
Dryer recovery 6,507.03
Dryer loss 163.97 = 2.45%
Calciner Recovery 3.887.00
Calciner loss 2,620.03 =40.10%
Total loss 42.55%
67
-------
Details of Operation
During the week of December 30, 1970, an attempt was
made to dry the wet paper sludge material in a parallel
flow rotary dryer. This proved to be somewhat successful,
however, the size of the unit, an 18" x 12' dryer limited
its capacity to under 400 pounds per hour for drying
purposes. It was then decided that a similar try would
be made by passing the wet material through the 3' x 30'
lined rotary kiln at 1200°F. and short retention time.
This was accomplished in two days, December 30 and 31,
1970. A rate of 950 Ibs/hr. was obtained in the unit
giving an end product at 1200 F. of 15 to 20% moisture
from its initial 74% moisture content. Starting on
January 4, 1971, the remaining 110 drums of wet material
left after the first initial drying attempt were fed
through the dryer on a 24 hour basis. The entire work
took until the morning of January 6, 1971. The total
recovery for the drying step came to almost 20,000
pounds.
The kiln was immediately adjusted to give a long reten-
tion time and temperatures of 1550 F. and the partially
dry product re-introduced to the system starting at
approximately 1000 hours on January 6, 1971. In order
to guarantee that the materials do not exceed the re-
quired 1500 to 1550 , two thermocouple probes were in-
stalled directly into the kiln load at the hottest
possible point. These were then used for controlling
temperature for the entire program. Adjustments were
started in the feed rate to the kiln at 1200 hours on
January 6. The first initial product from the unit had
a gray cast to it. At 1830 hours on January 6, it was
decided that the color problem was due primarily to a
lack of oxygen towards the back end of the kiln and also
the low back end temperatures. At that point, the primary
air fan to the burner system was put on to increase total
air flow through the system. By 2100 hours, the first
product, which indicatedgood color, was produced.
High abrasive levels were obtained, so on the morning of
January 7, a decision was made to reduce the burning zone
68
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temperature to 1500 F. This required a reduction in
the feed rate in order to maintain color. On January 7,
by 1100 hours, indications were that the abrasive level'
requirements were being met, and that the color seemed
to be stable indicating a good brightness. The kiln was
being run at its lowest possible speed which was in this
case 0.48 RPM giving a total retention time of approxi-
mately 3 hours within the kiln. The kiln produced
approximately 35 pounds an hour for the remainder of the
program. All attempts to increase this capacity gave an
indication of an off-white color returning. This was
being done by a visual inspection.
Since the figures for abrasiveness seemed to stablilize
at an acceptable level, it was decided to maintain these
conditions for the entire run. The conditions were held
stable through January 10, 1971 at which time the run was
terminated at 1930 hours. Upon completion of the run,
the fall-out chamber was opened and checked for the first
time. It was determined that if this was done during the
course of the run, it would upset the burning conditions.
At this time, approximately 1100 or 1200 pounds of material
was removed from the fall-out chamber. This material is
believed to have been blown back immediately from the feed
pipe due to the re-introduction of the material into the
feed end gas stream in the dry state. This had a tendency
to increase the overall loss out of the system which did
not report out as product. Total product recovery proved
to be around 60% of the initial starting material. All
products obtained during the course of the run, including
hourly samples, were sent to the Bauer Brothers Company.
Equipment
Equipment in this test program consisted of the following:
3' x 30' kiln, which is lined with 70% alumina brick
4 1/2 inches thick. It has a variable speed range between
0.48 and 4 RPM, and a slope control between horizontal
and 3/4" per foot. The exhaust end gases of the kiln pass
through a brick fall-out chamber and then to a bag collector
or to atmosphere when using natural draft. Temperatures
in the kiln hot zone were measured optically and by direct
69
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thermocouple probes within the load. View ports are
located in the firing hood. The kiln is fired with
the #2 fuel oil.
Pug Mill
The pug mill used in this program was an 8' long unit
with variable speed drive. It consists of a single
shaft chopping blade arrangement. Additional blades
were added to the last 3" of the unit for this test to
insure satisfactory shredding of the feed material.
The pug mill was hand fed from the drums.
70
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PROPERTIES OF DOMESTIC #2 FUEL OIL
API Gravity No. 33.3
Heating Value: 139,000 Btu's/gallon gross
130,400 Btu's/gallon net
Flash Point 154°F.
Distillation: 10% at 425°F.
50% at 505°F.
90% at 580°F.
End Point 630°F.
Ash 0.001%
CHEMICAL ANALYSES
Carbon 87%
Hydrogen 12.5%
Sulfur 0.5%
Oxygen 0.1%
Nitrogen 0-1%
71
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APPENDIX G
HURRICANE MILLING OF CALCINED SLUDGE
Material
01 - Light calcined sludge as received; 17.6 Ibs per
cubic foot and a brightness of 84.8.
02 - Grey calcined sludge as received; 18.0 Ibs per
cubic foot and a brightness of 50.9.
Objective
To demonstrate the ability of the Hurricane Pulverizer-
Classifier to grind sludge to 99.9% minus a 325 mesh
screen, and to upgrade by impurity extraction.
Summary & Conclusions
This material ground to average .80 micron compared to
1.7 micron in the last test.
The material was increased in brightness by 2 points in
Run W2.
The two types of materials were kept separate and marked
when shipped.
The Pulverizer can be highly recommended for grinding
this calcined sludge.
Procedure
The Bauer Model No. 724 Hurricane was used for grinding
and extracting impurities. The machine set-up is shown
on Table No. I and the laboratory data is shown on
Table No. II.
Wet wash screen analyses were taken at 10 pounds of
pressure.
The processed material was sent to S. D. Warren for further
evaluation.
73
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TABLE I
January 25, 1971
Run
No.
W-l
W-2
W-3
Run
No.
No.
1
ROTOR
21"
II
II
FRONT
DAMPER
OPENING
INCHES
No.
2
ROTOR
21"
II
II
BACK
DAMPER
No . No .
3 4
ROTOR ROTOR
Blank 21"
II II
11 II
SKIM-
MER
OPENING OPENING
INCHES
INCHES
No.
5
ROTOR
21"
M
II
FEED
SCREW
PITCH
AND
RATIO
INNER
DISC.
DIAM.
(INCHES)
AND
No.
5/21
11
II
UPPER
FAN
DIAM.
INCHES
No.
FINGERS
IN
CLASS-
IFIER
24
II
M
BAFFLE
I.D.
INCHES
W-l
W-2
W-3
1/2"
5/8"
5/8 "
1/2"
5/8"
5/8"
4x2
II
II
5x4
12:18
II
II
28
II
II
18
II
H
NOTE: TWO ANGLE IRON DEFLECTOR USED ON CLASSIFIER SHELF.
74
-------
TABLE II
January 25, 1971
MAT'L MACH. R.P.M. LBS. TIME LBS. H.P. OUTLET STACK
NO. FED (MINS) PER USED AIR MAN-
HR. TEMP. OMETER.
°F. IN. OF
01 -
01
02
MAT'L
01
01
02
^24 3080
M n
n n
POUNDS
EX-
TRACTED
3.7%
4.5
3.6%
105
3 . 7%
24
120 4.5
2945 90.0
651 21.0
SPECIFIC
GRAVITY
2.58
tl
11
1600 66
1960 75
1860 75
FISHER
PARTICAL
SIZE
0.81
0.80
0.88
150
160
160
BRIGHTNESS
84.6
86.8
70.6
-2
-2
-2
%
-325
MESH
99.996
99.996
99.950
NOTE: Equipment operated to extract rejects,
75
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APPENDIX H
EVALUATION OF CALCINED SLUDGE AS A FILLER PIGMENT
Introduction
The Government Grant project concerns a possible
solution to mill sludge disposal which entails calcining
at a controlled temperature to burn out organic matter
without causing abrasiveness and grinding to produce a
pigment for mill reuse. This report covers a handsheet
evaluation as filler pigment of a sample from a con-
siderable quantity of such material calcined by Traylor
and ground by Bauer. An evaluation of the same pigment,
designated W-2 (2/12/71), for coating applications is
underway. These combined studies should indicate the
best possible mill reuse application for this pigment,
which will then be tried in a mill run.
Summary
A pigment sample was dispersed at 15% in water under low
shear conditions. It did not disperse very well and left
a number of soft aggregates which would not pass a 120
mesh screen. There was no appreciable grit detected and
dispersion should be much improved with higher shear con-
ditions.
Abrasiveness against copper was determined by the New Jersey
Zinc Method as described in TAPPI, Vol 43, No. 7, July,
1960, Pgs. 230A-232A. Weight loss averaged 18.5 mgs. which
is in the same range as Hi Opaque clay. This latter
material, although testing several times more abrasive
than filler clay, has been in use at Cumberland Mills
for several years with no apparent ill effects.
The W-2 dry pigment brightness determination is 83.4 and
chemical assay is 14.3% as CaO, 9.2% Ti02 and 76.5% clay.
For evaluation of physical and optical properties of W-2
as a loading pigment, four sets of 50 Ib. handsheets,
of 20 sheets per set, were made on the Noble Wood recir-
culating mold.
77
-------
The furnish used was 60% Penobscot Bleached Hardwood
Kraft, 40% Pictou Bleached Softwood Kraft, cobeaten in
the Cycle beater to a Canadian Standard Freeness of
370. Preslurried W-2 pigment at levels of 12 and 28%
based on fiber was added to the thick stock while similar
levels of Columbia Filler Clay were used for controls.
Fifteen Ibs per ton of cooked Sta-Lok 333 cationic
starch was added at the sheet mold as a retention aid
and pH of the system was maintained in the 7.5 - 9.0
range.
The last five sheets of each set were tested for physical
and optical properties and these results appear in
Table I and Graphs I & II.
Conclusion
The W-2 pigment appears to have desirable properties as
a filler pigment, particularly for its opacifying power.
Slurrying may prove to be a minor problem - with the
available mill equipment - and brightness, although
somewhat superior to filler clay, is not very good. W-2
tends to increase bulk in the sheet and retains well.
It would seem to be well-suited for grades where TiO«
is currently used for opacity but brightness is not of
top importance.
78
-------
TABLE I
W-2 Pigment Filler Clay
12% 28% 12% 28%
Basis Weight
25 x 38, 500
Bulk
Mils/Sheet
Bulk Factor
cc/gm.
B + L Opacity
(C89 @ 50 Ib)
Kube Ika -Munk
S x 102
K x 104
Alinco
Brightness
Mullen Burst
Dial
% Mullen
% Ash In
Sheet
% Filler In
Sheet*
% Pond to Wire
Boi-on t- i nn
50.4
6.3
2.15
90.8
8.1
12.6
79.4
24.0
47.0
8.5
10.2
94.8
49.5
6.5
2.25
95.2
11.0
18.6
79.3
13.0
26.1
20.2
24.3
70.8
50.0
6.2
2.13
87.9
7.1
9.5
79.1
25.0
49.9
9.6
11.2
70.4
49.1
6.0
2.10
90.4
8.4
11.4
78.3
15.0
30.7
18.6
21.6
71.9
*Ash Factors: W-2 =0.83
Columbia Filler Clay =0-86
79
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APPENDIX I
DEMONSTRATION GRANT - PAPER MACHINE TRIAL
Purpose
The purpose of this report is to describe the procedures
and results of the paper machine trial using calcined
sludge as a filler pigment.
Procedures of the Trial
Pigment Slurry
The pigment was slurried in the Cowles dissolver with
water at 20% solids. Lab work indicated that the
sludge filler was difficult to disperse. As a result
a fifteen minute treatment in the Cowles was used to
slurry the sludge. All batches in the Cowles showed
soft lumps on a 120 mesh sieve. The high pH of the
sludge caused the white water pH to jump from 8 to 10.6
in an hour. As a result froth became more noticeable.
Alum addition was used to correct this problem.
Furnish Preparation
The pigment slurry was added to the pulp mixture in the
beaters in proportions shown below.
Furnishes: English Finish
Basis Weight 45-lb 45-lb 70-lb 50-lb 50-lb
Blank T T T T*
99621 99828 99830 99829 99829
Hardwood(%) 30 30 30 30 30
Broke (%) 70 70 70 70 70
Clay (%) 19.6 — 6.4 6.4 —
Titanium Dioxide 2.5
Sludge Filler (%)-- 19.6 14 16.8 22.4
Starch (gpm) 1.0 1.0 1.0 1.0 1.0
Size (gpm) 0.4 0.4 0.4 0.4 0.4
Alum (gpm) ~ 0.25 0.25 0-25 0.25
*Low Brightness
Sludge
Size Press: 5.2 to 6.2% of PG 280 solids.
81
-------
Paper Machine Running
The trial was started at 9 a.m. Previous to that time
the paper machine had been making 45 pound (per 3300
ft. ) Publishers English Finish Offset, which was used
as a blank for trial comparison. The trial was started
on the same grade. After two rolls of the 45 pound
were made, the basis weight was changed to 70 pound.
Three rolls of the 70 pound were made and the basis weight
was changed to 50 pound. Total running time of the
entire run was 15 1/2 hours - from 9 a.m. on 3/31/71 to
12:30 a.m. on 4/1/71. A summary of the weight of paper
produced follows:
Grade
Pub.E.F.
Order No,
99828
99830
99829
Basis Weight,
per 3300 ft."
45 Ib.
70 Ib.
50 Ib.
Number
of Rolls
2
3
5
Total Wgt,
Made
3600 Ibs.
4400 Ibs.
5980 Ibs.
Testing
During the paper machine run the Quality Control Depart-
ment tested the paper as it normally does to assist the
Paper Machine Department in making the paper to the de-
sired specifications. The Research Department also tested
the paper and took samples of the wet end of the paper
machine to determine pigment retention.
Paper Machine Department Test Results
Filler retention: 45-lb. Blank
45-lb. Trial
45-lb. Trial
70-lb. Trial
Print Ratings:
Wax - Ash Tests
45-lb. Trial
70-lb. Trial
50-lb. Trial
45-lb. Blank
45-lb. Blank
45-lb. Trial
70-lb. Trial
59.8% without alum
22.5% without alum
55.0% with alum
70.6% with alum
Fair
Fair
Fair
Fair Plus
Wax Ash
14 16
18 12
13 17
82
-------
Wax
50-lb. Trial - 13
45-lb. Blank - 13
Research Department Test Results
Basis Tear G.E.
Sample Reel Wgt. Mullen W/A Bright
45-lb.
Blank 2 44.55 23 37/31 75.76
45-lb.
Trial 1 43.45
45-lb.
Trial 2 39.52
70-Ib.
Trial 1 68.05
70-lb.
Trial 2 70.13
70-lb.
Trial 3 65.10
50-lb.
Trial 1 47.40
50-lb.
Trial 2 47.44
50-lb.
Trial 3 48.08
* Corrected to 45-lb. basis weight
** Corrected to 50-lb. basis weight
SX102 KX104 Fold W/A MI Size
27 31/33 76.24
20 28/33 76.56
31 61/70 77.24
35 70/72 77.38
32 61/68 76.62
24 34/31 74.78
25 40/49 73.86
245 38/45 73.14
Ash
16
16
Opacity
92.44/92.6*
90.74/91.3*
92.52/94.3*
97.98
98.02
97.74
94.28/95.3**
94.76/95.7**
94.62/95.0**
Gurley Bulk
Density Factor
45-lb.
Blank
45-lb.
Trial
45-lb.
Trial
70-lb.
Trial
70-lb.
Trial
70-lb.
Trial
9.
8.
10.
10.
8.
9.
10
31
31
09
78
56
23.
23.
26.
25.
19.
25.
8
2
0
2
1
3
36/26
117/28
99/31
42/14
53/25
46/34
33
28
10.
26.
20.
59.
9
5
8
1
10
61
73
29
41
51
.2
.9
.5
.3
.8
.6
1
1
1
1
1
1
.08
.10
.32
.26
.32
.21
83
-------
2.95 69/29
50-lb.
Trial 9.50
50-lb.
Trial 9.38 32.9 105/31
50-lb.
Trial 9.19 34.8 57/38
14.0
6.6
18.1
87.3
55.3
64.1
1.12
1.19
1.11
One of the critical tests on a trial of this sort is the
Quality Control Print test. This involves printing 100
sheets (17" x 22") of the paper on a commercial sized
Miehle offset printing press which is housed in the
Print Testing Department. Samples of almost all printing
papers produced at the Westbrook mill are tested by this
technique on a 24-hour basis. After the paper is printed
the printer rates the printability of the paper as Good,
Fair+, Fair, Fair-, and Poor. If the rating is poor, the
paper is rejected for shipping as first quality; Fair-
is a borderline condition; and Fair, Fair+, and Good are
shippable in first quality.
Results
Generally, the results of this run were very good. The
paper met at least the minimum specification in all the
tests, and in some cases was better than spec. The major
problem of the run was the high pH of the pigment slurry,
which caused poor retention at the start. The addition
of alum reduced the pH to normal and the retention im-
proved.
The opacifying power of the calcined pigment was good
enough to produce the desired opacity at lower than
normal ash levels. Therefore, on the 70 pound and part
of the 50 pound clay was added to meet the ash spec.
Since clay is less expensive than fiber it is advantageous
for us to run the ash level as high as possible and still
meet the strength specifications of the product, even
though the opacity is over spec.
The low brightness calcined sludge produced the desired
shade properties without any dye being required. This
means that this pigment would be adequate for low
84
-------
brightness papers, but inadequate for high brightness
papers.
Conclusions
The Demonstration Grant calcined pigment can be used as
a filler for making some grades of printing papers. The
high pH of the slurried pigment will require more care
and control than our normal pigment additions. This is
not a major deterrent to the use of the calcined pigment,
however.
85
-------
APPENDIX J
PRINT TRIAL - DEMONSTRATION GRANT
Purpose
The purpose of this report is to present the results
of the commercial print test on the Demonstration Grant
Paper.
Discussion
In order to get a reasonable evaluation of the Publishers
English Finish made on #8 Paper Machine under the De-
monstration Grant Project, the Sales Department arranged
for 1000 sheets of the 50 pound paper to be printed at
Livermore and Knight Company in Providence, R. I.
The form being used was a biology book for D. C. Heath
Publishers. Bookman Offset (50 pound) was the paper
being used to make the book and the trial paper was
printed at the trial-end of the run. On May 11, one
side was printed on a 77" Miehle offset press, two-color
(black and green) , 4000 impressions per hour. The paper
ran very well on the press, produced an excellent print,
and the blankets and press were clean after printing.
The other side was printed on a 77" Harris four-color
press at a rate of 2300 impressions per hour. The paper
again ran very well.
In addition the Print-Testing Department at S. D. Warren
printed the Supplement to "Warren's Standard" on May 24
and 25, 1971, and the following is a summary of press
conditions.
Press: Harris 26" x 27" LUS
Sheet Size: 17 1/2" x 22 1/2" grain long
Number of Pages : 12
Finished Size: 8 1/2" x 11" booklet
Offset Blanket: Dayco Black #8312
Ink: General Printing Ink, Publication Black NC66-1580
Ink Tack: 12.8 o
Fountain Solution: Lith-KemKO Etch. 14 Baum Gum
Arabic, Isopropyl Alcohol
pH of Fountain Solution: 3.5
Printing Plates: Warren Fotogold 12 Pt.
87
-------
Folder: Baum 23" x 32"
Number of Sheets Printed: 30,000
Bindery: Northeast Bindery, 335 Forest Ave., Portland
Conclusions
This commercial printing trial of the Demonstration Grant
Paper was a success with no problems. " •
The paper performed satisfactorily at S. D. Warren on
both the printing press and bindery operations. Some
static electricity was noted, but not enough to give
production problems. The blanket showed a slight filler
buildup after 10,000 impressions in the non-image area.
Felt hairs and clay lumps were also noted. None of the
above created print interference.
The sheets delivered a good flat load with the ink drying
and binding to the surface very well. From the Print-
Testing Department's point of view the sheet showed
good runnability for single color work.
88
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APPENDIX K
FULL SCALE SYSTEM
Cost estimates from the Fuller Company and the Bauer
Brothers Company detail quite accurately the major com-
ponents needed for a 40 tpd full scale sludge pigment
recovery system. In addition to those costs the follow-
ing should be added:
Material Mill Labor Sub-Contract Total
Pumping Sta. for
Dilution Water
Mix Tank, Agita-
tor & Controls
Pumps & Piping
Centricleaners
Vacuum Filters
Sludge Conveyors
Pigment Storage
& Distribution
Building
10,000
3,000
7,000
20,000
15,000
17,000
42,000
78,000
25,000
3,000
5,000
1,000
10,000
2,500
3,000
15,000
7,000
12,000
2 , 500
21,000
37,000
50,000
100,000
30,000
140,000
100,000
$427,000
20,000
15,000
$59,500
40,000
100,000
$186,500
200,000
215,000
$673,000
Sub Total $673,000
Freight 5,000
Contingency @ 15% 102,000
Total $780,000
Bauer Bros, submitted a quotation covering the No. 724-
Pulverizer System that will handle 1-Ton per hour of feed.
This quotation covers all of the grinding, collecting
equipment, motors and starters. In addition to this
equipment, a hopper ahead of the pulverizer and piping
and wiring to and from the starter panel are required.
Construction prices vary from one area to another so
installation costs are not given.
Transportation charges are $5.00 per hundred.
89
-------
The total weight on the No. 724-Pulverizer System would
be approximately 9000 Ibs.
Operating requirements of the System
After the equipment is setup and operating, it would
only require a touring operator for periodic checking.
The machine can be torn down and rebuilt within four
(4) hours after the maintenance people become familiar
with the machine, and if a hoist is installed for re-
moving the heavy parts.
Parts cost on calcined clay has been running 30 to 50
cents per ton.
No fuel required on the Pulverizer.
Electrical requirements covered in the quote.
Following are the load weights on the various items
quoted:
No. 724-Pulverizer with motor - 4430 Ibs.
No. 25-Exhauster with motor - 570 Ibs.
Starter - 400 Ibs.
84FK-40 Flex-Kleen Collector - 3600 Ibs.
Quotation
One Model No. 724 Bauer Hurricane Pulverizer of welded
carbon steel construction. Equipped with whizzer
classifier and integral high pressure fan. With high
alloy replaceable rotor blades, classifier fingers with
carbide face. The mill housing to be lined with Ni-hard
liners and the classifier housing section to be lined
with M-alloy. Equipped with a screw feeder with a 1/2
H.P., D.C. variable speed motor, feed hopper, drive
chain and sprockets, circulating oil pump with 1/4 H.P.
TENV motor and four gallon reservoir. Including Dyna-V-
Belts and Sheaves.
Price $15,875.00
90
-------
One 75 H.P., Type K, 1800 RPM, 3 phase, 60 cycle, 460
volt, vertical Motor, dripproof design, with special
shaft and sliding base for belt drive.
Price $ 1,284.00
One Integrated Starter and Automatic Control System
consisting of a NEMA-12 enclosure containing a mainline
circuit breaker, a main motor starter, (cross-the-line) ,
a lube pump motor starter, feed drive solid state D.C.
converter, circuit protection device, wired complete
with sequence interlock and ready for mounting. Also
included is an operator's station (for remote mounting)
consisting of a percent of load indicating ammeter
(main motor) start-stop stations for lub pump, main
motor and feeder motor, feeder drive speed adjustment
control mounted in a NEMA-12 enclosure for 460 volts,
3 phase, 60 cycle service.
Price $ 2,520.00
One Special Feed Hopper with magnetic Grate Bars, in-
stalled in a Drawer type frame for easy cleaning and
inspection.
Price $ 650.00
One Model 84FK-40 Dust Collector, carbon steel con-
struction including 60 hopper cone, quick opening
side and top access doors, inside walkway, compressed
air header, solenoid valves, internal air piping, 11 oz.
dacron filter bags, mild steel bag cages, type 304 s/s
bag clamps, solid state and mechanical stepping switch
relay timer, prewired and magnehelic pressure gage,
air pressure gage.
Price (F.O.B., Chicago, Illinois) $ 3,640.00
One Model No. C-8" Rotary Airlock with 1/2 H.P.,
T.E.F.C. Gearhead motor, complete with chain drive
91
-------
guard and mounting plate. For lower end of Dust
Filter Cone.
Price $ 995.00
One Model No. 25 Exhauster with Belts and Sheaves, in-
cluding a 5 H.P. motor, 1800 RPM, 460 volts, 3 phase,
60 cycle open motor.
Price $ 667.00
Total Price $25,631.00
NOTES: The above prices are F.O.B., Springfield, Ohio,
except where otherwise noted, and are firm for 60 days.
These prices do not include any taxes which, if applicable,
are to be paid by the Purchaser.
Service Supervision will be supplied at the rate of
$100.00 per diem, plus Travel and Living Expenses,
however, on New Equipment Start-Up, the $100.00 per
diem charge will be waived for the first day. (1)
The price of motors and other electrical equipment
are subject to escalation based on the motor manufac-
turers' discounts at the time an order is received.
TERMS: Net 30 days from date of invoice.
DELIVERY: Estimated within 3 to 4 months.-
The Fuller Company submitted budgetary information
covering a rotary kiln and associated equipment as
follows.
Based on the information obtained during the various
tests run on S. D. Warren material in their Research
Department, it is estimated that the equipment for the
40 TPD application would require a feed at 70% moisture
92
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!!!U^^g^° ??? TPD and the "aterial or product exit-
discharge would be approximately
The equipment offered would consist of a rotary kiln,
and this kiln would be so equipped with a suitable
chain section so that in effect the kiln becomes a
combined dryer and kiln.
It is estimated that the fuel requirements per ton of
material fed to the kiln as feed would be approximately
3,260,000 BTU's and basing this figure on the material
discharged from the kiln the thermal requirements per
ton of material or product discharged from the kiln would
then become approximately 23,500,000 BTU's.
40 TPD
For this application, we would suggest the use of a
rotary kiln, 6' 6" diameter x 160'0" long. This kiln
would be on a slope of 3/8" per foot and have a reten-
tion time of approximately 240 minutes. The kiln would
be equipped with the necessary drive and auxiliary
drive, feed end housing and discharge end fire hood.
The kiln would be equipped internally with a suitable
chain section.
Also included in this package would be the supply of a
Peabody Mechanically Atomized Type Burner with a maximum
heat release of 24,000,000 BTU's/hour. This burner
would be of the water cooled type and would be equipped
with a suitable Duplex Pump and Heater Set which would
utilize steam for the preheating of Bunker C oil. The
pump and heater set would have a maximum capacity of
4 GPM. The burner pipe itself would be equipped with a
suitable primary air fan and damper for controlling the
volume of air to the burner. The burner package would
also include a suitable flame failure device for insurance
purposes. Also included in this package would be the
necessary ducting to connect the primary air fan to the
•burner pipe. It should be noted, however, that this
93
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No.
4. Title Sludge Material Recovery System for
Manufacturers of Pigmented Papers
7. Author(s)
Labrecque, R. P. and Weymouth, T. E,
9. Organization
S. D. Warren Company
A Division of Scott Paper Company
Westbrook, Maine 04092
12. Sponsoring Organization
15. Supplementary Notes
3. A ccession No.
w
5. Report Date
6.
S. Performing Organization
Report No.
10. Project No. EPA
12040 FES
11. Contract/Grant No.
13. Type of Report and
Period Covered
16. Abstract
A process was developed and tested in a full scale trial wherein the
pigment present in waste sludge was reclaimed. Sludge resulting from
the primary treatment of white waters was diluted to less than 0.75%
solids, centricleaned, dewatered to 30% solids, shredded, dried, and
burned in a rotary kiln. The ash that resulted - the pigment - was then
pulverized and used as filler pigment in the papermaking process.
A pigment of acceptable abrasiveness and a GE brightness of 84-85% could
be produced provided that the sludge was centricleaned and the temperature
in the kiln kept below 1600°F.
A system capable of processing 40 dry tons per day primary treatment
sludge would produce reusable filler pigment at a net cost of $50 per ton.
Compared to the delivered cost of virgin filler clay ($38 per ton) it can
be seen that full scale pigment recovery utilizing this system is not
economically justifiable at this time.
17a. Descriptors
* . *
Material Recovery Wastes, Pulp and Paper Wastes, Sludge , Incineration ,
Pigment Recovery .
17b. Identifiers
Centricleaning Sludge, Paper from Sludge, Pulverization, Burning,
Solid Wastes, Sludge Treatment.
17c.COWRRField & Group 05D, 05E
18. Availability
19. Security Class,
(Report)
20. Security Class.
(Page)
Abstractor
^^^^^^^^^^^^^^^
WRSIC 102 (REV, JUNE 1971)
21. No. of
Pages
22. Price
Institution
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U S. DEPARTMENT OF TH E INTERIOR
WASHINGTON. D. C. 20240
GP 0 913.26!
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