July, 1919
T H E JOlTRNAL OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
The gas next passes through a drying tower containing soda lime and calcium chloride, thence through a 3way stopcock and on out of t h e apparatus through a water seal. By means of t h e 3-way stopcock samples of t h e residual gas could be taken a t pleasure for t h e analysis of methyl ohloride. Table I1 shows results of chlorinating larger amounts of gas, using t h e three most promising catalyzers. A great many charcoals, cokes, etc., were tried but t h e yields, from a carbon tetrachloride standpoint, were not as good and are not given in this report. Increasing t h e gas rate produced products of a boiling point below 70' C. The boiling point and specific gravity of these fractions indicate a mixture of chloroform and carbon tetrachloride. The products boiling above 8 j " C. indicate a mixture of carbon tetrachloride, carbon hexachloride, and other chlorine products. These percentage yields may be in error t o some extent, due t o t h e above assumptions, but are of value in t h a t they are useful for comparing the selative efficiency of the different catalyzers.
643
Results show t h a t natural gas can be completely chlorinated on a laboratory scale a t one operation. The temperature range extends from about zzj" C. t o j o o ' C. when using war-gas charcoal. Moisture helps t h e reaction. A t a rate of I 1. of natural gas per hr. t h e methane goes completely t o carbon tetrachloride and t h e ethane t o carbon hexachloride when using a maximum amount of chlorine. When larger rates of gas were used chloroform was found along with the carbon tetrachloride. T h a t carbon tetrachloride and chloroform can be produced successfully is proven, provided the right catalyzer is used, t h e conditions of the reaction are carefully watched, and efficient means for removing the products are used. Ethane is chlorinated much more easily than methane and a t a lower temperature. Catalyzers for complete chlorination must be such that they have a high absorption value for chlorine. ACKXOWLEDGMENTS
I n compiling this report the authors wish t o acknowledge the helpful suggestions made by G. B. Taylor, chief chemist of the Pittsburgh Station, Major A. C. Fieldner, of t h e Chemical Warfare Service, Lt. S. H. Kate and Sgt. Linchfield for supplying two of the catalyzers, hf. H. Meighan and W. L. Parker for carrying on t h e tests, and F. E. Donath, glass blower, for making t h e scrubbers and other parts of the apparatus.
4n I
FIG. 3 - L O W - P R E S S U R S
SCRUBBER
Table I11 shows t h e different chlorides of methane and ethane with their boiling points and their specific gravity, as given in Watts' chemical dictionary and Landolt-Bornstein tables. These are given here for comparison of the products obtained by chlorination of natural gas. POSSIBILITIES
Processes and methods must be found t o use t h e large supply of chlorine which will be available a t the conclcsion of peace. Natural gas is a very cheap commodity in out-of-the-way places, and chlorine can be made by using part of the natural gas for power. I n this way the expense for raw material will depend only on the value of the natural gas. Chloroform besides being used in surgery is a good solvent. Carbon tetrachloride is a good solvent, non-explosive and non-inflammable. It can be used for t h e extraction of certain fats, resins, waxes, dry cleaning, and for fire-extinguishing compounds. Carbon hexachloride has no uses at present b u t can be reduced t o ethane tetrachloride which is a good solvent used extensively in the manufacture of motion picture films, aeroplane dope, varnish manufacture, paint remover, etc., CONCLUSIONS
Apparatus is shown and described for the chlorination of natural gas. Results of tests are given pertaining t o the complete chlorination of the gas.
BUREAUOF M I N E S DEPARTMENT O F INTERIOR WASHINGTON,
D.
c.
THE TANNIN CONTENT OF REDWOOD By CHARLBSC. SCALIONE AND DAVIDR. MERRILL Received December 16, 1918
The rapid depletion of t h e more accessible supplies of tanbark oak ( P a s a n i a dertsiflora), which is t h e only natural source of tannin largely utilized on the Pacific Coast, suggested the desirability of a study of the wood of t h e coast redwood (Sequoia semperv i r e n s ) , which is known t o contain tannin and of which a large supply is available in the form of refuse from t h e lumber industry. With this idea in view, samples of bark, heartwood, and sapwood were obtained from Mendocino County. The bark was shredded and ground in a mill to pass a 20 mesh screen. Samples of the heartwood and sapwood were prepared by sawing, and grinding the sawdust to pass 2 0 mesh. The moisture contents were determined by drying samples t o constant weight. The undried samples were extracted by soaking them for several hours in warm water, pouring off this extract, and extracting the residue with more water in an extractor of the Soxhlet type. The extraction was stopped when the extract gave a negative test with the salt gelatin reagent for tannin. The mixed solutions were diluted t o volume, and clarified by adding washed kaolin and sucking them into a flask through an alundum extraction thimble. After this treatment the samples passed the require-
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
644
ments for optical clearness as given in the A. L. C. A. specifications. The following results were obtained using the A. L. C. A. hide powder method. The results are calculated t o a dry basis in each case. Bark Per cent
........ 2 . 7 6 . . . . . . . . . 1.89
Soluble solids.. Non-tannins Tannin..
.............. 0 . 8 6
Sapwood Per cent 4.77 3.62 1.15
Heartwood Per cent 25.7 13.5 12.2
I t is evident from these figures t h a t the only part of the redwood which has any possible value as a source of tannin is the heartwood. The principal source of raw material here would be the sawdust. The proportion of soluble non-tannins is high, which is in part due t o the method of extraction used. The extract gave a qualitative test for pyrogallol derivatives. The liquors were quite dark from the coloring matter which occurs in the redwood. A sample tanning was run on some strips of hide. The grain developed quickly and struck through in about four days. The outside of the hide was colored a dark purplish brown, but the color did not penetrate through the hide. For heavy sole leather this material might be satisfactory. Another possible source of tannin from redwood is in the liquor which collects on steam-kilning the wood. While a quantitative analysis of these liquors was not made, they appeared t o contain about 7 t o I O per cent tannin when the salt gelatin test was made. I n the same connection it should be noted t h a t Scalione and Blakemorel found t h a t the leaves of Ceanothus velutinus were quite rich in tannin. This shrub covers a large acreage in certain regions of California and could be collected in large quantities a t but small cost. The experimental work outlined above was performed in the chemical laboratory of the University of California in the fall of 1 9 1 7 . AMERICAN UNIVERSITY EXPERIMENT STATION WASHINGTON, D. C.
TREATMENT OF LOW-GRADE NICKEL ORES2 By C. W. DAVIS Received November 4, 1918
INTRODUCTION
This investigation was undertaken a t the Golden, Col., Station of the Bureau of Mines in a n attempt t o find some practical method for the commercial separation of nickel from low-grade ores. The use of nickel in nickel steel for the manufacture of gun forgings, structural work, automobile parts, etc., makes i t indispensable in normal times and doubly so under conditions brought about by a state of war. Although the United States is the largest refiner of nickel, the crude copper-nickel matter comes principally from the Sudbury district of Canada and from New Caledonia. A comparatively small quantity of nickel is recovered in the refining of blister copper from domestic ores, and no direct production of nickel from nickel ores in t h e United States is known t o have been made since 1
THISJOURNAL8
2
Published by permission of the Director of the Bureau of Mines.
(1916), 411.
Vol.
11,
No. 7
1909, a t which time the American Lead Company operated a smelter a t Fredericktown, Mo., for a short peri0d.I Altogether the situation for the production of nickel from ores found in the United States is not. encouraging.2 Two nickel ores were used in this work, one from North Carolina, the other from Chichagof Island, Alaska. THE N O R T H C A R O L I N A ORE-The North Carolina ore occurs as an extensive deposit near Webster, Jackson County. This ore, as received, was in t w o forms, the lump and the fine. The lump material was a weathered, massive conglomerate, containing inclusions of mica, magnetite, and ferric oxide with incrustations of serpentine and genthite. When pulverized, a brown powder resulted which resembled ferric oxide. The fine portion, which constituted more than three-quarters of the total ore, was similar t o the ground lump material but of a somewhat lighter color. An analysis of a representative sample of the nickel ore is as follows: Per cent 56.5 22.0 4.1 .............. 1.2
Si02 and insoluble matter. .......................... FelOs .............................................
..............
MgO . . . . . . . . . . . . . . . . . . . . . . . . . .
......................
0.0
99.9
The ore thus contains 0 . 9 7 per cent metallic nickel! and must be considered very low grade, since it has been shown3 t h a t an ore from New Caledonia containing less than 4.4 per cent nickel, as silicate, is of n o commercial value a t present, the cost of treatment equalling the value of the nickel contained. T h e same thing is true of the sulfide ore from Sudbury carrying 2.03 per cent nickel. I n fact i t is considered unprofitable t o treat a Sudbury ore for nickel alone if i t runs less than 3 per cent nickel. The genthite portion of the North Carolina ore when roughly separated gave a content of 9 . 5 per cent nickel oxide. W. L. M o r r i ~ o n ,who ~ did considerable work on ore from Webster, which averaged 1 . 7 5 per cent nickel oxide, states: “The present plant for commercial operations is out of the question. The wet process now existing is also out of the question. The only process available for this ore a t present is the electric furnace process in a first-class, efficient plant.” T H E A L A S K A oRE-The massive sulfide ore occurring a t Chichagof Island, Alaska, consists mainly of pyrite, chalcopyrite, and pentlandite. An average analysis is as follows: Per cent c u. . . . . . . . . . . . . 1.7 N i . ............. 3.7
Ca
Per cent 1.7
.............
I n portions the nickel runs as high as 5 . 7 per cent, and the copper up t o 4 per cent. Report of the Royal Ontario Nickel Commission, 1917. Eng. and Min.J . , Jan. 20, 1917. 3 Report of the Royal Ontario Nickel Commission, LOC.cit. 4 Trans. A m . Eleclrochem. SOC., 20, 315. I 2
