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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 C H E M I S T R Y
The use of this method of protection is further desirable because proper bituminous coverings offer resistance to stray electrical currents. Of course, no addition of waterproofing compounds or substances can be relied upon t o counteract completely the effect of bad workmanship, and the production of impermeable concrete can be hoped for only where there is determined insistence a t all times on good workmanship on all structures.
FULLER’S EARTH The United States Bureau of Mines has just issued a pamphlet (Bulletin No. 21) by Charles L. Parsons, on Fuller’s Earth. Dr. Parsons states that “The United States produces all of the fuller’s earth used for refining petroleum within its borders. On the other hand, most of the fuller’s earth used in bleaching edible oils has been imported from England. Recently a few of the refiners of cottonseed oil have begun to utilize domestic fuller’s earth, whereas others have been unable t o substitute it successfully for English earth in their practice. Many samples of American earth distinctly superior in bleaching powder to the English earth have come t o the attention of the Bureau of Mines. For these reasons an investigation of the mining, preparation, and use of fuller’s earth in this country, especially in its application to edible oils, was conducted in order to ascertain why our own raw material has been deemed inapplicable to our needs. “During the calendar year 1912,according to figures of the United States Geological Survey, there were imported into the United States 1,970 tons of unground fuller’s earth, valued at $11,619,and 17,139tons of ground fuller’s earth, valued a t $133,718,these values being based on the wholesale market price a t the port of origin. The addition of transportation charges, commissions, etc., make the price t o the American refiner $14.50t o $16 per ton. According to the latest figures compiled by the United States Geological Survey, the United States in 1912produced 32,715 tons of fuller’s earth, valued a t $305,522 or $9.34 per ton, at the mine. Most of this domestic production was from three plants in Florida and one in southwestern Georgia and was used almost wholly for decolorizing petroleum. A small amount from other localities was used in the refining of edible oils. No figures definitely differentiating fuller’s earth from other clays are kept in regard to our exports, but-it is certain that several thousand tons of domestic earth were exported to Germany, and it is also true that German refiners of edible oils have used and are using large quantities of American fuller’s earth and have a higher appreciation of its merits than our own refiners. “As a result of the investigations made, the Bureau of Mines believes that the United States has fuller’s earth far better suited for refining edible oils than any imported, and that to assure the almost universal use of this earth by American refiners there is required only a careful and intelligent technical control of the preparation of the output and its application to the bleaching of oils.”
NEW CHEMICAL PROCESS FOR FIBER A new process of manufacturing cellulose has been worked out by Dr. J. Konig: Balsam, fir, pine, spruce, beech and oak woods, as well as spun fibers, may be transformed into a very fine, easily bleachable cellulose, with a cattle feed substance residue, and the elimination a t the same time of the waste liquor troubles. The Journal of the Society of Chemical Industry (Oct. 15, 1913,p. 939) states that the disintegrated wood or other fibrous material is steamed with four to five times its weight of a 3 to 5 per cent solution of ammonia under a pressure of 2 to 3 atmospheres for five or six hours. The liquor is removed by pressing and the residue is washed with boiling water, the ammonia being recovered by distillation of the liquors, with the addition of lime, if necessary; resins and tannins are obtained
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from the residue from distillation. The digested material is next steamed in a similar manner with 4-5 times its weight of 0.4 to 0.6 per cent sulfuric acid for 6-8 hours under a pressure of I to z atmospheres. The liquors from this treatment contain sugars, the products of the hydrolysis of hemicelluloses and pentosans. These liquors are neutralized either with the lime employed for the recovery of the ammonia or else with powdered limestone and evaporated. The syrup obtained is separated from the calcium sulfate and mixed with dry fodder, chopped hay, brewers’ grains, bran, etc., and fed to cattle. An alternative process consists in steaming with sodium carbonate solution instead of ammonia in the first stage and with hydrochloric acid in the second stage, and mixing the waste liquors from each process so that they neutralize each other; the sodium chloride thus formed is not injurious to the use of the evaporated syrup as a fodder. The exhaustive alkaline and acid treatments do not remove the lignin from the wood, and the residue still contains over 25 per cent of lignin. This, however, is in a form which is readily oxidizable by hypochlorite bleach liquor and the fiber is treated in stages, preferably with dilute sodium hypochlorite, until a residue of bleached cellulose is obtained. It is estimated that 2 0 0 pounds of wood yield six pounds of resin (or two to four pounds of tannic acid), fifty pounds of fodder extract rich in sugars and sixty-two to eightytwo pounds of bleached cellulose.
SEWAGE DISPOSAL IN NEW YORK Number 6 of the Preliminary Reports of the Metropolitan Sewerage Commission of New Uork is the presentment of a study of the collection and disposal of the sewage of the lower Hudson, lower East River and Bay division. Number 7, in the same series, includes the critical reports of G. J. Fowler, of Manchester, England, and J. D. Watson, of Birmingham, England, on the projects of the Commission. These experts agree in advocating the construction of main drainage channels t o carry off the sewage of lower New York into the Atlantic Ocean,
EXHAUSTING LAMP BULBS AT HIGH TEMPERATURE According to Scientific American (Oct. 18,1913),a new method is used for making a vacuum in incandescent lamps or other glass vessels. Heretofore, to eliminate the last traces of moisture and expel air bubbles which adhere to the side of the glass, the lamps have been heated in a special furnace lined with asbestos to equalize the heat to a temperature of 250 or 350’ C. But all the air bubbles do not detach even a t this heat, and a greater heat cannot be used for fear of softening the glass, when the air pressure would collapse the bulbs. Quite lately the Berlin Allgemeine Company used a vacuum process which permits heating to a higher point and even softening the glass while the lamps are on the air pumps. This is done by placing the lamps in an electric furnace in which a vacuum is made, so that there is scarcely any external pressure on the lamps and they can be heated as high as 500’ C. Larger end tubes can be used on the lamps which is better for the vacuum process, but it is a hard matter to fuse off such large tubes for closing, when they have a vacuum inside, as collapsing may occur. An original method is used for this, and a spiral wire electric heater surrounds the tube so that it is softened and can be drawn out while still inside the furnace; the closing off of the lamp is thus effected without air pressure on the outside. Then the surface is allowed to cool down to 350’ C. before opening and putting on the atmospheric pressure. ____
CADMIUM STORAGE BATTERY PLATES Scientific American (Oct. 18, 1913)reports t h a t Forseke and Aschenback use a new process for making cadmium electrode plates for alkaline accumulators. They use cadmium obtained in finely divided form as a spongy precipitate from a solution
