Pressure Time Minutes
Temperature
0 70 133 180 240 100 160
590
420 460
591 591 590 594 590
51,
613
7 14 Y2Z 1093 111s 1323 1333 1340 134s 1358 1365 1398 142x
C. 592 589 591 591 591
590
(quite low a t times) ca. 590 590 593 590 610 609 630 608 60'1 590
Kilos. per sq. cm 121 121 119 5 118 117 115.5 114 112.7 112 166 1.57 145 131
1 18-1 15 156 166 165 165 164 163 162 160 158
Velocity Liters per hour 11 11 11 11 11 11 11 11
11 20 20 20 20 20 20 20 10 10 20 20 3
3 3
Ammonia P e r cent. 2.8 3 .Os 3.1 3.13
3.15 3 09 3.05 3 02 d .02 +2.85
*2.70 $2.50 * I .97 *2 .00 2.68 2.74 3.60 3.80 3.00 3 15 5 05 5 50 5 .50
cent. at j o j o C., and 2j.7 liters per hour: 9.1 per cent. a t 496" C., and 9 . j liters per hour; and 11-11.9 per cent. a t j03'-493O C., and 2 liters per hour. Osmium.-Finely divided osmium proved a very effective catalyst. (In both the iron and chromium groups of metals, the metals of highest atomic weight possesscd catalytic properties far superior to t h a t of the metals of lower atomic weight.) In a series of experiments with a layer of osmium 14mm. long and 4.5 mm. diameter, 4.75 per cent. of ammonia was obtained a t j92O C. and 156 atmospheres pressure and a velocity of 20 liters per hour. At the same pressure, j.91 per cent. was obtained a t j 7 z o C., and I O liters per hour; 7.9 per cent. a t I;+ atmospheres, 550° C., and 1 . j liters per hour; and over 9 per cent. a t j 2 1 O C., 174 atmospheres, and 1 . j liters per hour. In a prolonged experiment with a small quantity of osmium (a layer 4 mm. diam. and I cm. long), 34 grams of ammonia were obtained, and the contact substance was more active after j 8 hours than after 3 hours. An experiment with gas circulation was carried out with osmium as catalyst. After pumping (Jut air from the apparatus (see Fig. 4) the mixture of nitrogen and hydrogen was introduced up to a pressure of 185 atmospheres, and the circulating pump set working. A current was now sent through the heating wire (17-18 amperes a t j 6 volts). The temperatures registered by the three junctions of the thermo-element varied from 58oo-63j0 C. a t t h a t next to the heat regenerator, from 7joo-82j0 C. a t the intermediate junction and from 8 8 0 ° - ~ 0 0 0 0 C. a t the first junction. A t first the liquefier was not cooled, and the ammonia content of the gas-mixture rose to 5.4 per cent. The liquefier was then cooled with a mixture of alcohol and solid carbon dioxide and kept a t - 2 5 O to -39O C., mostly -30° C. The experiment was continued for 4 hours, the pressure ranging from 193 to 163 atmospheres. The ammonia content of the gas varied from 2.4 to 3.1 per cent., mostly 2.6-2.9 per cent. (Higher figures would have been obtained with a larger quantity of contact substance.) About joo cc. of liquefied ammonia (corresponding to 336 grams or 475 liters of gas atordinarytemperature and pressure) were obtained in the 4 hours. The heat- and coldregenerators acted very efficiently. The copper capillary through which the gases left the furnace could be held comfortably in the hand quite close to the furnace. The cold regenerator had a thick coating of ice on the side where the gases entered from the liquefier, while on the other side it was a t the ordinary temperature. At the end of the experiment the residual gas mixture contained 30 per cent. of nitrogen plus argon.
CHEAPER ALUMINA AND ALUMINUM FROM MINERAL SILICATES' B y ALFREDH . COWLES
If two briquettes be formed, one of kaolin (or clay) containing 19 parts of anhydrous pure clay and twenty-three and four tenths parts of salt; the other of 15 parts of charcoal to IOO parts of the first mixture; and these two briquettes, alike in size and form, be kept heated with water vapor in an oxidizing atmosphere a t a temperature equal to or just above the vaporizing temperature of salt, it will be found t h a t each briquette begins to be converted over its surface into a sodic-silico-aluminate which would have the formula of (Na,O),.(SiO,),.Al,O, if the clay and salt were pure. The vibrating gaseous molecules of watery vapor and oxygen bring about this change over all exposed surfaces of the two briquettes. However, this difference in conversion will be found: the briquette containing no charcoal will require nine times a s long f o r the conversion to penetrate to its center between walls, as the briquette containing charcoal. This result is not self-apparent, as the reaction requires an oxidizing atmosphere to oxidize the sodium produced before it volatilizes out of the briquette. That this result would occur was based upon hypothetical reasoning on my part, and its demonstration as a truth was brought about by experiments performed in the laboratory of The Electric Smelting & Aluminum Company a t Lockport, New York. By coincidence, Dr. Adolf Kayser was my assistant in performing the experiments. Dr. Kayser in the early '90's attempted to develop this reaction commercially, using briquettes containing no charcoal in largc: kilns of a down-draft nature. The work had proved a failure as had also the work of William Gossage in 1862, and t h a t of Gruneberg and Vorster about 1874-76, During these experiments, Dr. Kaj-ser was of the opinion that they could not succeed because, as he thought they would produce reducing conditions. The experiments, however, proved t h a t the conversion penetrated the briquettes nine times faster when charcoal was in them, than was the case ivhen the briquettes contained no charcoal. This result taught that it was necessary to expose large surfaces or porous masses to bring about a rapid conversion. This could be effected in more than one Tray, but the problem of cooling the gases and simplifying the elimination of dust led to the adoption of a tunnel furnace of the Grondal type, with modifications to render it suitable for the process. The fact that the reaction could be made to proceed rapidly, opened up an entirely new vista, one of assured success t o the process. It meant t h a t the volume of fuel gases and nitrogen necessary to pass through thc charged furnace would become so far reduced as to permit of efficient commercial condensation of the hydrochloric acid evolved. It meant the employment of cheap fuel, sawdust, or charcoal made from sawdust with possible by-products from the same, and far greater capacity of output with the same cost of plant. It meant t h a t the process could be applied to other aluminous materials such as potash feldspar mixed with chloride of potash or salt, securing the chemically equivalent reaction. Dr. Kayser had evolved a method of opening or rendering leachable alkali-silico-aluminate containing sufficient alkali, which means nearly one molecule more than that which occurs in feldspar. This he did by heating to a sintering temperature two molecular weights of lime to each molecular weight'of silica in said compound, after which the product may be leached and the alkali aluminate very effectively removed. Our company acquired this patent from him. The process is easily understood. I n the manner in which we are attempting to perfect it a t Sewaren, h-ew Jersey, in our present work, briquettes similar to those in Fig. I are formed I Paper presented a t the Joint Meeting of the American Electrochemical Society, American Chemical Society and Society < i f Chemical Industry, Chemists' Club New York, February 7 , 1913.
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