Extractable Waxes from American Lignites LABORATORY INVESTIGATION W. H. ODE AND W. A. SELVIG Bureau of Mines, Pittsburgh, Pa.
, b
PI
I
Because of the shortage of montan wax during and after World War I1 and the fact that American industry in the past had to rely largely on foreign sources, a laboratory investigation was started by the Bureau of Mines in 1945 to obtain information concerning yields and properties of solvent-extractable wax from domestic lignites. Results of the survey showed that of the lignitic coals examined, the highest yields of extract were obtained from certain Arkansas and California lignites. Some of these yields were similar to those obtained in commercial extraction of montan wax from German brown coal. The lignites examined from Montana, North Dakota, Texas, and Washington gave appreciably smaller quantities of solvent extract than the Arkansas and California lignites.
Although higher yields of extract were obtained with a solvent mixture of benzene and alcohol than with benzene alone, the properties of the benzene extracts more closely resembled commercial grades of imported montan wax than did the benzene-alcohol extracts. The most significant difference between the extracts obtained in this investigation and the Riebeck brand of montan wax from Germany was the greater resin content of the extracts from domestic lignites; they more closely resembled a commercial grade of montan wax from Czechoslovakia. The benzene-alcohol extracts had a higher content of asphaltic material than the benzene extracts. The resins and asphaltic material probably could be removed from the crude extracts by solvent refinement.
S
one investigation (11) that yields of solvent extract from the American lignites examined were low and probably would be unprofitable under conditions at that time, even if the wax content approached that of European brown coals. In connection with briquetting tests (19) of certain domestic lignites to determine the percentage of bitumen or natural binding material in the raw and briquetted fuel, solvent-extraction tests with carbon disulfide were made with the following results (dry basis): briquets from Ione lignite, Amador County, Calif., 7.0 to 8.4%; North Dakota lignite, 1.1 to 1.8%; and Texas lignite, 1.3 to 1.9%. Abraham (1) reported that Graefe (7) obtained 2.07% of montan wax from dried Texas lignite. Glenk (6) found that extraction of Mansfield, La., lignite with several solvents yielded 0.5% or less of wax. Extraction of Velva lignite from North Dakota with benzene under pressure yielded up to 4.3% of extract on a dry, ash-free basis, and Harris, Belcher, and Gauger (9) concluded from this study that the portion of the extract obtained up to a pressure of 17 atmospheres had a composition closely analogous to montan wax from German brown coal.
OLVENT extraction of certain lignitic coals yields a wax termed montan wax. A wax having somewhat similar properties is obtained also from certain peats. Montan wax is essentially a mixture of waxy constituents consisting of monohydric alcohol esters and high molecular weight acids, with some resinous and asphaltic material (6, 1S, 16, 18). The proportion of these components depends both on the source of the lignite and the solvent used in the extraction process. I n this paper the term wax or montan wax is used in a broad generic sense to designate the substance obtained by solvent extraction of lignites. These crude extracts in many instances contain large proportions of resinous and asphaltic material. The commercial grade of montan wax is a high-melting, hard, brittle wax which has many industrial uses. It is an important ingredient in certain polishes, electrical insulating compositions, leather dressings, inks, carbon papers, protective coatings, greases, and other compositions (2,8). Montan wax requirements for industry in the United States before World War I1 were met by imports, nearly all of which came from Germany. In 1939 more than 7 million pounds of montan wax valued a t $700,000 were brought into the United States. At the beginning of the war these imports were shut off, and American industry was forced to rely largely on substitutes. Since the war montan wax has not been available from Germany, but relatively small amounts have been imported from Czechoslovakia. During World War I1 the American Dyewood Company operated a plant at Malvern, Ark., for making dyes or stains and extracting wax from Arkansas lignite. This plant has been closed since 1945. The investigation reported herein was begun by the Bureau of Mines in 1945 to obtain information concerning solvent extraction yields of domestic lignites and comparison of properties of the extracts with commercial grades of montan wax. lNVESTIGAT1oNS OF AMERICAN LIGNITES
OF
Little published information is available concerning solvent $‘extractionof domestic low-rank coals. It was concluded from
SOURCE OF SAMPLES EXAMINED
The investigation of domestic sources of wax of the montan type described in this report was confined to examination of lignitic coals, with some tests on subbituminous coal. No work was done on peats. The lignitic coals examined were obtained for the most part from areas in which the deposits have been developed commercially. Samples were examined from Arkansas, California, Montana, North Dakota, Texas, and Washington. Lignite deposits, perhaps some of considerable extent, are known in Alabama, Louisiana, Tennessee, Mississippi, and South Dakota; but, with the exception of those in South Dakota, they have not been exploited, and little is known about them. No sampling was done in these states for the present study. Table I shows typical analyses and the usual range of analyses of the coals examined. Probably the most significant difference in analysis of the lignites is the generally higher volatile matter and hydrogen contents on a moisture- and ash-free coal basis of the Arkansas and California lignites. The volatile matter con131
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Vol. 42, No. 1
TABLE I. ANALYSES OF COALSEXAMINED
State
Proximate Analysis of Typical Sample, as Received, % Volatile Fixed Sulfur Moisture matter carbon Ash
Usual Range of Analyses, % Volatile Matter, Calorific Ash, Moisture\ ~ of ~ l ~ ~ -MoisturMoistureand Sample, Receivedas N ~ of. As Received Air Dried Free -4sh-Free B.t.u./Lb: samples Low High Low High Low High Low High
Hydrogen, Moistureand Ash-Free Low High
LIGNITIC COALS
Arkansas California Montana North Dakota Texas Washington King County Lewis County
38.1 37.3 39.0 38.2 33.5
32.1 32.9 25.1 26.7 30.9
22.6 21.4 30.2 29.3 29.7
7.2 8.4 5.7 5.8 5.9
0.3 1.0 0.5 0.3 0.6
7060 6280 6810 6750 7610
14 4 2 10 Q
51.4 27.7
25.3 27.3
15.5 24.2
7.8 20.8
1.2 0.7
4420 6160
1 3
35
42
32 34 32
39 43 36
9 7 10 13 15
51
15 11 14 20 22
20 22 10 14
9
13 9 7 9
11
16
55 61 45 46 49
16
5.7 5.7
61
70 47 51 52
4.9
62
4.9 4.8
6.6 7.4 5.5
5.5
27
29
16
17
14
29
51
54
5,3
5.6
26
29
9
12
7
11
45
51
4.3
5.2
46
5.0
6.4
47
5.2
6.6
S U B B I T U M I N O U S C COALS
Wyoming
28.8
30.1
36.3
4.8
0.3
8470
4
SUBBITUMINOUS B C O I L S
Colorado Montana Oregon Wyoming
25.8 19.0 15.1 22.6
28.4 27.9 34.4 31.8
42.2 45.4 41.6 36.3
3.6 7.7 8.9 9.3
0.3 1.0 0.7 0.7
9280 9610 9820 8770
tent of the Arkansas and California lignites is about 10 to 15% higher than that for the lignites examined from the other localities; the only exception is the brown coal sample from King County, Wash. The hydrogen contents of the Arkansas and California lignites are also about 0.5 to 1% higher. The volatile matter and hydrogen contents of the subbituminous coals on a moisture- and ash-free basis are about the same as those of the Montana, Xorth Dakota, Texas, and Washington lignites. SOLVENT EXTRACTION YIELDS
Investigative work on European brown coals and lignites showed that the yields as well as the properties of the waxes are affected considerably by the type of solvent used in the extraction process. The choice of a solvent, therefore, will depend somewhat on the desired properties of the wax. The solvents reported to have been used in the German montan wax industry include a mixture of 80% benzene and 20% ethyl alcohol ( I d ) , and a mixture of 85% benzene and 15% unrefined wood alcohol (containing methyl and isopropyl alcohol) (17). An examinatZionof records of the I. G. Farbenindustrie A. G. by Cawley ( 3 ) showed that an extraction process using benzene alone was the simplest process to operate. However, the solvent power of the aromatic hydrocarbons was not considered to be sufficient to remove all of the wax, as the colloidal properties of the coal are lost during drying. The colloidal properties are reported to be regained on adding an oxygen-containing solvent, and both tho extraction rate and yield of wax are increased. The solvents sed in determining the extraction yields of domestic lignites reported in this paper have been confined largely to benzene and a solvent mixture of 80 parts by volume of benzene and 20 of 95y0ethyl alcohol. The extraction tests were made in duplicate in the usual type of Soxhlet apparatus on air-dried samples crushed to pass a No. 20 sieve. Extraction of samples crushed to pass No. 60 and No. 200 sieves was slow because of difficulty of percolation of the solvent through the finely divided lignite. However, preliminary tests showed that the extraction yields of the lignitic coals were not significantly increased by fine grinding. The yields of extract from the coals examined were determined for extraction periods up to 12.5 hours. The results showed that nearly all of the wax was extracted in the first few hours, as illustrated in Figure 1 for a Dallas County, Ark., lignite. At the end of the extraction period, the wax solution was transferred to a short-necked, round-bottomed flask and the solvent removed by distillation. The last traces of solvent were removed from the extract under reduced pressure, first
3
21
2 1
15
1
19 23
26
9
15
10
13 14
15
5
12
11
PO 12
13
40
15
45
38 47
...
..l
...
with a water-aspirator pump, and finally to constant weight a% 100" C. with a mechanical vacuum pump. Care was required in removing the last traces of solvent as the extracts frothed considerably until all of the solvent was removed. Table I1 summarizes the yields of solvent extract that were obtained in examining 43 samples of lignite and 11 samples of subbituminous coal from mines, outcrops, and drill holes. The yields are reported on the air-dried coal basis and also calculated to the moisture- and ash-free coal basis. For a few coals, benzene extraction tests were made of samples dried at 105' C., but t h e extraction yields were less than those obtained on air-dried samples when compared on the same basis. Although no attempt was made in this investigation to determine the reason for the difference in yields, a possible explanation may be that the colloidal nature of the coal was changed during the severe drying so that the permeability of the solvent into the dried particles was reduced. Higher yields of extract were obtained for all of the samples examined using a solvent mixture of benzene and alcohol than with benzene alone as solvent. The properties of the extracts, however, were different, as will be shown later. The table shows that of all the lignitic coals examined, t h e 12
10 w
z z 0
$ 8 D
P
a Li_
0
$ 6
i?
sm> i
5 4 Y C n. x'
3 2
0
2
4
6 R TIME OF FYTRACT'SN HOURS
10
12
Figure 1. Cumulative Removal of Wax from Lignite
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 1950
133
YIELDSOF SAMPLESEXAMINED TABLE 11. EXTRACTION
State
Source
County
Number of Mines, Outcro s or Drill €foies Sampled
Range of Extraction Yields % Moisiure- and Ash-Free Basis‘ Air-Dried Coal Basis Benzene Benzene-alcohol Benzene Benzene-alcohol extraction extraction extraction extraction
P
Number of Samples Examined
LIGNITIC COALS
Arkansas
...
.... ..
2.9 4.4- 5 . 4 3.6
El Paso Jackson wnia M&elshell
1.3
Fremont
...
4.7 4.1 2.5 2.0 2.2- 2 . 9 4.6
1 1 2 4 1 2 4 1 1 1 1
Wyoming
Carbon Converse Weston
1 1 1
Colorado
California Montana
North Dakota
Texas c
6.4 13.3-17.4 20.4-22.7 13.5-15.1 17.1 17.3-19.9 11.8-27.9 3.7 2.6 2.9 3.5 3.0 3.0- 3 . 3 3.0 3.5- 3 . 7 3.8- 4 . 5 5.0- 6.6 5.7- 6 . 4 5.7 4.4- 4 . 8
Clay Dallas Hot Spring Ouachita Poinsett Saline Amador Powder River Sheridan Burke Burleigh Divide Mercer Mountrail Ward William Harrison Milam King Lewis
Washington
I
1 4 2 4 1 2 4 1 1 1 1 1 2 1 2 2 5 4 1 3
2.5 6.3- 8 . 9 9.5-11.1 6.3- 7.3 7.6 5.7- 9 . 4 6.6-14.2
... ... ... 1.2 1.3 ... ...
1.3 1.6 1.5- 2.4 1.7- 2 . 1 2.0
...
5.1 10.0-13.0 14.9-16.4 10.2-11.7 11.0 9.6-14.4 9.5-21.2 2.9 2.1 2.1 2.8 2.8 2.3- 2 . 4 2.3 2.7 2.6- 3 . 4 3.6- 4 . 8 4.4- 4 . 8 4.3 2.6- 3 . 3
3.2 8.4-11.4 13.0-15.3 8.5- 9 . 5 11.2 10.3-13.0 8.2-18.8
...
... .
.
I
1.5 1.7
...
1.7:. 1 . 8 2.1 2.1- 3.3 2.2- 2 . 8 2.7
’
BUBBITUMINOUB C COALS
1 2 1
... .. .. ..
2.3 3.6- 4 . 4 3.0
I
.
.
BUBBITUMINOUE B COALS
Montana Oregon Wyoming
r*
.L
coos
highest yields of solvent extract were obtained from certain Arkansas and California lignites. Some of the yields from the Arkansas and California lignites were within the range of 10 to 15%, which corresponds to yields reported for German brown coal used for commercial montan wax extraction. Fourteen samples of Arkansas lignite were examined from I 1 abandoned strip and drift mines and outcrop exposures in Clay, Dallas, Hot Spring, Ouachita, Poinsett, and Saline Counties. With the exception of the sample of Clay County lignite which contained only small quantities of extractable material, the yields of benzene extract ranged from 5.7 t o 11.1%, and those of the benzene-alcohol extracts from 9.6 to 16.4% on an air-dried coal basis. I n extraction tests of four samples of lignite from Amador County, Calif., yields of benzene extract rangedfrom6.6 to 14.2%, and the yields of benzene-alcohol extract, from 9.5 to 21.2%. These yields cover about the same range as most of the Arkansas lignites tested. Some of the Ione lignite mined in Amador County contains relatively high concentrations of extractable material as shown by analysis of two grab samples of wax-rich lignite not included in Table 11; these samples yielded 19.6 to 27.0% of benzene extract and 31.5 to 38.3% of benzenealcohol extract. The lignites examined from Montana, North Dakota, Texas, and Washington contained appreciably smaller quantities of solvent extract than the Arkansas and California lignites. Yields of benzene extract ranged from 1.2 t o 2.4%, and yields of benzenealcohol extract from 2.1 t o 4.8% on an air-dried coal basis. Subbituminous coals examined had about the same range of extraction yields. Extraction tests of bench samples from the Texas and one of the Arkansas lignite beds examined showed no significant concentration in any of the benches which would indicate that their selective mining would be advantageous. The differences in solvent extraction yields from the various lignites are accounted for by differences in petrographic composition, an investigation of which is described in another report (16). The wax-rich lignites are of the attrital type whereas the xyloid or woody type give lower yields of solvent extract.
.,. ... ... ...
PROPERTIES OF EXTRACTS EXAMINED
The following properties of the extracts were determined: melting point, acid value ( 4 ) ,saponification value (d), ester value, “resin” (IS),“asphaltic” material, and ash. The term resin is usually applied t o the fraction of wax that is relatively more soluble in certain cold solvents such as ethyl ether, ethyl acetate, ethyl alcohol, and mixtures of benzene and alcohol than are the other constituents. Ethyl alcohol and benzene-alcohol solvents are reported to be used in commercial deresinification of montan wax in Germany. The asphaltic material in montan wax is defined as that portion of the wax which is insoluble in hot aromatic-free petroleum ether (12). METHODS OF WAX EXAMINATION
MELTINGPOINT.The melting point method used in this investigation was confined to the closed capillary tube procedure. In this method a sample of crushed wax is placed in a capillary tube that is about 1mm. in diameter and closed a t one end. The depth of the wax in the tube is 1 to 2 cm. The samples are heated a t a rate of 1’ C. per minute in an apparatus designed by Hershberg (IO)in which accurate temperature control can be maintained. RESIN. One gram of powdered wax is placed in a Biichnertype funnel having a fritted glass disk of medium porosity. Ten ml. of ethyl ether are poured over the wax, and the solvent with dissolved resin is allowed to drain into a weighed flask. Extraction is continued with nine additional 10-ml. portions of ether. After completion of the extraction, the solvent is removed from the resin by distillation, the last traces being removed under reduced pressure first with a water aspirator pump and finally t o constant weight at 100’ C. with a mechanical vacuum pump. Completeness of extraction is determined by treatment of the residue in the funnel with five 10-ml. portions of ether; not more than 1 to 2% of additional ether-soluble extract is obtained. ASPHALTIC MATERIAL. One gram of powdered wax mixed with 10 grams of clean sand is extracted in a Soxhlet apparatus with aromatic-free petroleum ether (boiling point, 86” to 100’ C.) After extraction is completed, the solvent is removed from the extract by distillation, the last traces being removed under vacuum
INDUSTRIAL AND
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N G I N E E R I N G CHEMISTRY
Vol. 42, No. 1
a t 100" C. The difference between the weight of the sample and the extract represents the weight of the asphaltic material. RESULTS OF WAX EXAMIhATION
Table I11 shows, with exception of the ash content, the chemical and physical properties of waxes that were obtained in this investigation. Examination was made of the waxes obtained by both benzene and benzene-alcohol extraction of Arkansas and California lignites. For samples from the other sources only benzene-alcohol extracts were tested, as the yields of benzene extract from the same coals were very low. The table also s h o w the properties of four samples of commercial grades of montan wax which were eyamined for comparison with the extracts obtained from the domestic low-rank coals. Two of the samples produced from German brown coal were Riebeck brand montan waxes; one of the samples consisted of crude wax, and the other of deresinified wax. The Czechoslovakian sample was described by the supplier as refined "Genuine Montan Wax'' having a melting point of 178" F. (81 C.). The "American Xontan Wax C" was a semirefined product prepared by selective extraction of a crude primary extract; the wax was submitted in 1948 by the American Lignite Products Company, Ione, Calif., which had recently begun commercial production of wax from California lignite mined in Amador County. All of the extracts examined were hard and brittle and could be matched with the fingernail. In mass they were black with a brownish hue. Fracture surfaces were conchoidal. When powdered, the benzene extracts were light brown, and the benzenealcohol extracts were dark brown. Examination of Table I11 shows that, in general, the properties of the benzene extracts more closely resembled the commercial montan wax samples than did the benzene-alcohol extracts. The melting points of the benzene extracts from the Arkansas and California lignites ranged from '77" t o 85" C. These values were similar to those obtained for the Riebeck brand of montan wax and commercial semirefined montan wax from California lignite; they were, however, slightly higher than that determined for the Czechoslovakian wax. The melting points of the benzene-al; coho1 extracts from the Arkansas lignites were generally about 5 to 15' C. higher than those obtained by benzene extraction. Their melting characteristics were also different in that the benzene-alcohol extracts from the Arkansas lignites appeared to form a more viscous melt than the benzene extracts. The melting points of the benzene-alcohol extracts from the California lignites were only slightly higher than those of the benzene extracts from the same coals. The benzene-alcohol extracts obtained from coals from the other sources had melting points that ranged from 7 2 to 82 C., temperatures which are similar to those of the commercial montan wax samples. The only exception was the wax from the Darco KO. 3 lignite in Texas which melted a t 83" to 87 O C. This wax appeared to form a very viscous melt. Acid values of the benzene extracts from the Arkansas and California lignites ranged from 36 to 40 and 44 to 51, respectively. All of the benzene-alcohol extracts had significantly higher acid values than the benzene extracts. The acid values of the benzene extracts agreed more closely with those of the commercial wax samples than did the benzene-alcohol extracts. The saponification values of the benzene extracts from the Arkansas and California lignites were lower than those of the benzene-alcohol extracts from the same coals. The ash contents of all of the extracts examined were 0.6% or less; these low values were similar to those obtained for the commercial wax samples. The most significant difference between the extracts obtained in this survey and the Riebeck brand of crude montan way was the greater resin content of the extracts from the domestic lignites as measured b y solubility in ethyl ether. I n this respect, they more closely resembled the Czechoslovakian montan wax, The resin content of the commercial semirefined montan wax from California lignite was similar to the Riebeck brand of crude wax. Solubility tests using the following cold solvents, ethyl alcohol, ethyl acetate, and a solvent mixture of benzene and ethyl alcohol confirmed the results obtained with ethyl ether. The values for the resin content should be considered as relative rather than actual values as the separation of the resin is not clean cut because of partial solubility of the waxy fraction. For example, in the commercial deresinification of Riebeck montan wax, the deresinified wax is reported to contain about 5 to 7% of resin, and the extracted resin about 60% wax and 40% resin (17'). The amount of asphaltlc material in the benzene extracts examined was quite similar to the commercial montan waxes. Considerably more of this material was found in the benzene-alcohoI extracts. It may be that many of the differences between the extracts obtained by benzene and benzene-alcohol extraction can be accounted for by the large differences in the amount of asphaltic O
U
O
O
January 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
’ 135
TABLE Iv. ULTIMATE ANALYSESO F WAX SAMPLES, DRYBASIS, 70 Source of Wax Ash Riebeck-brand montan wax. not, de. . ~ _ ~ ~ ~~~. -~ resinified 0.3 Czechoslovakian montan wax 0.4 Lignite from Hot Spring County, Ark. Benzene extract 0.1 Benzene-alcohol extract 0.2 Lignite from Ione, Amador County, Calif. Benzene extract 0.1 Benzene-alcohol extract 0.4 American montan wax C 0.3 ~
u
Q
Oxy en, by
Difference
~~
material in the extracts obtained with these different types of solvents. The compatibility with paraffin wax of the extracts obtained in this investigation was examined. The tests were made by adding 0.5 gram of wax to 1.0 gram of melted paraffin in a porcelain crucible. The crucible was gently heated and the waxes mixed by a swirling motion. None of the waxes obtained from the domestic low-rank coals were completely miscible with paraffin because of their content of resinous and asphaltic material. I n all cases considerable black sediment settled on the sides and bottom of the crucible. The Czechoslovakian montan wax showed the same degree of incompatibility. The Riebeck brand of montan wax and the commercial semirefined montan wax from California lignite, however, were completely miscible with paraffin, and no black sediment was observed. Tests were made also of the b a n zene extracts from which the resin had been removed by solution in ethyl ether. The results showed that the compatibility was considerably increased by removal of the resin. No improvement was noted in similar tests of deresinified benzene-alcohol extracts, probably because of their greater content of asphaltic material. Compatibility tests with carnauba wax were made also of the wax obtained from the Arkansas and California lignites. All of the benzene extracts were almost completely miscible with carnauba wax; the benzene-alcohol extracts were not as compatible. Ultimate analyses of two imported montan waxes, extracts from an Arkansas and California lignite, and a commercial semirefined montan wax from California lignite are shown in Table IV. The range of analyses was as follows: carbon, 77.3 to 80.2y0,; hydrogen, 10.6 to 12.6%; oxygen, 6.8 t o 10.4%; sulfur, 0.3 t o 0.8%; nitrogen, 0.0 to o.3yO;and ash, 0.1 to 0.4%. The benzene extracts contained slightly more carbon and hydrogen and less oxygen than the benzene-alcohol extracts. The oxygen contents of the benzene extracts more closely resembled those of the commercial wax samples than did the higher oxygen benzene-alcoho1 extracts. Studies of possible improvement of the solvent extracts by various known methods of purification and refinement were not made in this investigation. However, from results obtained in the determination of the resinous and asphaltic material in the extracts by selective solvent extraction, removal of these constituents, if required, probably would be feasible. SUMMARY
*)
Hydrogen Carbon Nitrogen Sulfur
The survey of the solvent extraction yields of American lignites showed that, of all the lignitic coals examined, the highest yields were obtained from certain Arkansas and California lignites. Some of these yields were similar to those obtained in commercial extraction of montan wax from German brown coal. The lignites examined from Montana, North Dakota, Texas, and Washington contained appreciably smaller quantities of extractable material than the Arkansas and California lignites. The yields of extract from the subbituminous coals examined were low. Although higher extraction yields were obtained with a solvent mixture of benzene and alcohol than with benzene alone, the properties of the benzene extracts more closely resembled commercial grades of montan wax than did the benzene-alcohol extracts. The most significant difference between the extracts obtained from American lignites in this investigation and the Riebeck brand of wax from Germany was the greater resin content of the extracts from the domestic lignites. I n this respect they more closely resembled a commercial grade of montan wax imported from Czechoslovakia. The benzene-alcohol extracts had a higher content of asphaltic material than the benzene extracts. If required, the resins and asphaltic material probably
12.6 11.7
79.7 79.2
0.0 0.2
0.6 0.3
6.8 8.2
11.4 10.6
80.2 78.4
0.2 0.3
0.4
0.4
7.7 LO. 1
11.8 10.9 12.2
78.9 77.3 79.3
0.1 0.2 0.0
0.6 0.8 0.3
8.5 10.4
7.9
could be removed from the crude extracts by suitable solvent refinement. ACKNOWLEDGMENT
The authors gratefully acknowledge cooperation of the following men in supplying samples of lignite for the investigation: H. B. Foxhall, Arkansas Resources and Development Commission; J. N. Payne, University of Arkansas; V. C. Robbins, McAlester Fuel Company; A. B. Wallen, California Clay Corporation; and B. C. Parks, H. J. O’Donnell, Herbert Fowler, A. I,. Toenges, arid T. R. J o k y , Bureau of Mines. The authors also wish to thank H. M. Cooper, Bureau of Mines, under whose supervision the analyses of the coals and ultimate analyses of the wax samples were made. LITERATURE CITED
(1) Abraham, Herbert, “Asphalts and Allied Substances,” 4th ed., p. 136, New York, D. Van Nostrand Co., Inc., 1938. (2) Bennett, H., “Commercial Waxes,” pp. 396-563, Brooklyn, Chemical Publishing Co., Inc., 1944. (3) Cawley, C. M., British Intelligence Objectives Sub-Committee, Final Rept. 1831, Item 22. (4) Cawley, C. M., and King, J. G., Dept. Sci. I n d . Research (Brit.), Fuel Research Tech. Paper 52 (1946); J . SOC. Chem. I n d (London),64, 237-42 (1945). (5) Fischer, Emil J., “Waschse, Wachsahnliche Stoffe, und Technische Wachsgemenge,” Dresden und Leipsig, Theodor Steinkopff, 1934; reproduced by Edwards Brothers, Inc., Ann Arbor, Mich., 1943. (6) Glenk, Robert, Louisiana Dept. Conservation, Bull. 8 , 36-8 (1921). (7) Graefe, Edmund, “Braunkohlenteer-Industrie,” Halle (Saale), Wilhelm Knapp, 1908. (8) Gregory, Thomas C., “Uses and Applications of Chemicals and Related Materials,” Vol. 1. D. 397. New York. Reinhold Publishing Corp., 1939. (9) Harris, E. E., Belcher, C. F.. and Gauger, A. W.. IND.ENG. CHEM.,23,199-204 (1931). (10) Hershberg, Emanuel B., IND.ENG.CHEM.,ANAL.ED.,8 , 312-13 (1936). (11) Hood, 0. P., and Odell, W. W., U . S. B u r . Mines, Bull. 255 (1926). (12) Ivanovssky, L., Petroleum (London),6 , 170-4, 176 (1943). (13) Kiebler, M, W., “Chemistry of Coal Utilization,” Vol. 1, chap. 19, pp. 677-760, John Wiley & Sons, Inc., 1945. (14) Palmer, G., Shillitoe, G. S., and Maomaster, A., British Intelligence Objectives Sub-Committee, Final Rept. 13, ltem 22 (1945) ; U. S. Dept. Commerce, Office of Technical Services, PB 7921. (15) Reilly, Joseph, and Kelly, Denis F., Eire Dept. Ind. and Corn., I n d . Research Council Bull. 3, 5-78 (1943). (16) Selvig, W. A., Ode, W. H., Parks, B. C., and O’Donnell, H. J.. U.S. Bur. Mines, Tech. Paper, in preparation. (17) Steinle, J. Vernon, Office of Military Govt. for Germany (U. S.), F I A T Final Rept., 737 (1946); U. 5. Dept. Commerce, Office of Technical Services, PB 11173. (18) Warth, Albin H., “The Chemistry and Technology of Waxes,” pp. 203-8, New York, Reinhold Publishing Corp., 1947. (19) Wright, C. L., U . S. B u r . Mines, Bull. 58 (1913).
RECEIVED May 19, 1949. Presented a t the Gas and Fuel Chemistry Symposium before the Division of Gas and Fuel Chemistry, AMERICANCHEMICAL SOCIETY, Pittsburgh, Pa., May 9 and 10, 1949.
