Document ZBgdKLeDQy12jzKrdzOndLRnJ
"N FOSSCO. INC. ' "DEVELOPMENT WORK FOR STEEL MILL PRODUCTS DIVISION Commercial Developmenc Department
Maceriel Development (cone.)
Asbestos Free Profex
Research on Low-Asbestos and Zero-Asbestos Profax was renewed during this month.
The 1Z
low-asbestos recipe XS-1385B from April 1971 is still the best
such recipe to date. XS-L385B uses a crysotile asbestos-clay suspension
system. The recipe, and some properties are:
13 ID 447 177A 117 X1790 546 X2772 319
75.5Z 0.7Z 4.3Z 1.0Z 4.0Z
10.5Z 3.0Z 1.0Z
suspension agents: high temp, fibers: form time: transverse strength: density: 60 min. heat loss (4/71) green strength
117,319 X2772.319 5.5 sec. @ 30 PSI 188.5-213.0 PSI
0.754-0.755 7400 BTU/FT2
low
The present problem with this recipe is that X-2772 has been superceded in our plant by X-3198 which is llc/lb. cheaper. New recipes with X-3198 have a lower percentage of the fiber because the final product seeas less dense with X-3198. XS-1385D has the following:
2.5Z of X-3198 (76.OZ 131D) density 0.747
trans. strength - 231.7 PSI 60 min heat loss ("4/72) * 9760 2TU
FT?
Except for the insulacing values the amount of X-3198 in X5-1385D seems gooc. It is not yet clear whether other raw materials changed between 4/71 and 4/72 have changed the insulacing properties or if it is due to the X-3198. Work is continuing.
In reference to Zero-Asbestos Profax, it has been found that a paper-clavsurfactane system may be substituted for the suspension system used in the XS-138S recipes. Several ercal pads have been tested using the following suspension system:
1.0Z 1.0Z 0.1Z
Hansne milled 117 X1281
267
continued
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(graph #5) gave near equivalent results on the Amitec using the same corrected background loss for both.
Field tests of XS 1385E #376 hot tops at U.S. Steel, Lorain were reported to us as being successful. A larger scale test will be our next step with emphasis placed on eliminating the poor corner filling experienced on the last production run. Slurry dilution may solve the problem but Arquad will not because it wasalready tried in the plant with no success. High forming and D.W. timer were experienced because of the incompabi1ity with the bentonite and the corner filling did not improve at the same solids level.
Asbestos Replacement in Profax and Proflex
Suspension has been the greatest problem of asbestos replacement. Some of the replacement methods and materials have been:
SOLIDS
GELLING AGENTS
FIBERS
Vermicul1te: adds to suspension especially in high fiber recipes, slags between 1000C and 1300C
RM 117: Works wel1 at 1% -2% except with Arquad; cheap, thixotropic. RH 252: Works well at 0 to 0.5%; non-thixotropic; very expensive. RM 445; Not as effective as 117, expensive.
X2782 sheared:
extensive shearing
results in very
bulky flowable
fiber.
1/4" carbon fibers:
still being tested, 1
expensive.
1
Calf 11: Good
1
suspension 0 to 6:', 1
very high form times;
Milled Fiberolass:
still being tested, !
42e/1b.
Another approach to the suspension problem has been to maximize the light weight filers and minimize the heavy fillers. X2286 is a light-weight filer now in use, but its 1300C sintering temperature means it has a limited use. X2295 has been tested as a replacement; has excellent high temperature properties but is so fine that it powders. Other fillers are being ordered from Cagle Pitcher.
High shearing has been discussed and a recipe utilizing sheared fiberglass was made in our lab with an osterizer and at Fit. using a 40 gallon pulper. Results were different and dependent on (1) pulping action, (2) pulping time, (3) blade sharpness, etc. It is agreed upon that this would be a very difficult method of obtaining the desired slurry.
In place of the extensive shearing of X2782 (1/2 or 1/4") we are now samoling some milled fiberglass where the hammermill screens are 1/32", 1/16", 1/8" and 1/4". In truckload or carload quantities this fiberglass is 2c/lb.
less than X3198; the price may make it impractical.
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We have kept in touch with Foseco Canada, their 8% to 9.5% X2782 recipes
have been tried here and at FIL with the results being poor suspension and much segregation.
The following tables show some of the recipes under consideration at the moment. In the Proflex table recipe 47 is Vince Mellows (FIL) solution for a Seal-On material. Our tests so far have not been so successful with this recipe but we are continuing to work with it. The boards made in England with this recipe do look promising.
% Asbestos % Solids
% H20 After 15
min settling Transverse Strength
Density Aporox. cost/100 lb'
PROFAX RECIPES
PROFAX 31
4.0% 12.5% 22.7%
200+
0.77
$2.60
XS-1385E
0.9% 12.5%
18.0%
252.0 0.83 S3.83
LAB RECIPE VM 21
0.0%
12.5% 14.0%
216
0.53 $11.58
% Asbestos % Solids % HjO after 15
min sett 1 ing
Compressibi1ity at
19 psi Transverse Strength Density
465 IB
10.83: 7.4%
NA
10-16%
24-40 0.47-0.50
'fil data
XS--14398
6.0%
7.4% 14.0%
11-16%
24-40 0.45-0.47
SM-6
0.0%
n.i%
Hk
26.1%
14.6 0.44
i 1 !
;
i j 1
f
47
0.0% 1 !%
22%-
21.2%
10.9
0.56
m 1
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\
4
The cose of XS1471 is about the same as EP4651B/Proflex. The suspension properties are not altogether encouraging but all ocher properties appear to be in the correct range.
Slurry Suspension (Uater layer after 15 min.) - 28Z
Transverse Strength
- 31 psi
Density
- 0.49 g/cc
Compressibility (@ 19 psi)
- 14X
High Temp. Shrinkage (1300*C for 1 hour)- 33Z
Tests on the "SAM" machine will be conducted as soon as it is available in the plant.
Los Asbestos Profa^
Poor comer filling on the Mark III remained a problem for EP5254/Profax (formerly XS1385E) even though the fibers were pulped initially and a very dilute solids concentration of 10.7Z was used. Two pellets (56 sets) of #376 hoc cops were shipped to the customer where they were tested. The results of the tests, were favorable but no metallurgical information was obtained. Improvements in flow characteristics and suspension of Che slurry will be attempted. If results look favorable, boards will be made on the "SAM" machine or Mark III whichever is available first.
Asbestos-Free Profa?- Development
The most promising recipe to dace is XS1472 but because of its hitrh css: (S3.10/ evt) the recipe is being modified. Suspension and flowability tests are now in progress on experimental recipes since these are two important properties required for proper forming on a multi-cavity cool on a Mark III machine. Hopefully hy the end of August the non-asbestos Profax^- recipe will be perfected in the lab oratory and tried in the plant.
Replacement of Silica Flour in Pretax*5-' 31
Work is in progress on the replacement of silica flour in Profax^-' 31 because of the new laws under OSHA which the federal government has issued. Thus far, 12 samples were tested in Profax1- 31 which included Kyanice, Kaolin Clays, Sail Clay and Mullites. Prices ranged from 1.0c to 17c/lb. plus freight. The best samples to dace which give the best forming and physical properties for the cost are American Colloid, M5177, 115176 and a 100 mesh Mullice as shown in Tabic "1. All are higher priced chan RM 1310. Further testing will be conducted on only the best samples for the price as time permits.
R. R. Ozurilla
oon/r1
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