Creative Chemistry: Descriptive of Recent Achievements in the Chemical Industries. Edwin E. Slosson
in irrigating the beet land. The beet molasses, after extracting all the sugar possible by means of lime, leaves a waste liquor from which the potash can be recovered by evaporation and charring and leaching the residue. The Germans get 5000 tons of potassium cyanide and as much ammonium sulfate annually from the waste liquor of their beet sugar factories and if it pays them to save this it ought to pay us where potash is dearer. Various other industries can put in a bit when Uncle Sam passes around the contribution basket marked "Potash for the Poor." Wool wastes and fish refuse make valuable fertilizers, although they will not go far toward solving the problem. If we saved all our potash by-products they would not supply more than fifteen per cent. of our needs.
Though no potash beds comparable to those of Stassfurt have yet been discovered in the United States, yet in Nebraska, Utah, California and other western states there are a number of alkali lakes, wet or dry, containing a considerable amount of potash mixed with soda salts. Of these deposits the largest is Searles Lake, California. Here there are some twelve square miles of salt crust some seventy feet deep and the brine as pumped out contains about four per cent. of potassium chloride. The quantity is sufficient to supply the country for over twenty years, but it is not an easy or cheap job to separate the potassium from the sodium salts which are five times more abundant. These being less soluble than the potassium salts crystallize out first when the brine is evaporated. The final crystallization is done in vacuum pans as in getting sugar from the cane juice. In this way the American Trona Corporation is producing some 4500 tons of potash salts a month besides a thousand tons of borax. The borax which is contained in the brine to the extent of 1–½ per cent. is removed from the fertilizer for a double reason. It is salable by itself and it is detrimental to plant life.
Another mineral source of potash is alunite, which is a sort of natural alum, or double sulfate of potassium and aluminum, with about ten per cent. of potash. It contains a lot of extra alumina, but after roasting in a kiln the potassium sulfate can be leached out. The alunite beds near Marysville, Utah, were worked for all they were worth during the war, but the process does not give potash cheap enough for our needs in ordinary times.
IN ORDER TO SECURE A NEW SUPPLY OF POTASH SALTS
The United States Government set up an experimental plant at Sutherland, California, for the utilization of kelp. The harvester cuts 40 tons of kelp at a load.
OVERHEAD SUCTION AT THE SAN DIEGO WHARF PUMPING KELP FROM THE BARGE TO THE DIGESTION TANKS
The tourist going through Wyoming on the Union Pacific will have to the north of him what is marked on the map as the "Leucite Hills." If he looks up the word in the Unabridged that he carries in his satchel he will find that leucite is a kind of lava and that it contains potash. But he will also observe that the potash is combined with alumina and silica, which are hard to get out and useless when you get them out. One of the lavas of the Leucite Hills, that named from its native state "Wyomingite," gives fifty-seven per cent. of its potash in a soluble form on roasting with alunite—but this costs too much. The same may be said of all the potash feldspars and mica. They are abundant enough, but until we find a way of utilizing the by-products, say the silica in cement and the aluminum as a metal, they cannot solve our problem.
Since it is so hard to get potash from the land it has been suggested that we harvest the sea. The experts of the United States Department of Agriculture have placed high hopes in the kelp or giant seaweed which floats in great masses in the Pacific Ocean not far off from the California coast. This is harvested with ocean reapers run by gasoline engines and brought in barges to the shore, where it may be dried and used locally as a fertilizer or burned and the potassium chloride leached out of the charcoal ashes. But it is hard to handle the bulky, slimy seaweed cheaply enough to get out of it the small amount of potash it contains. So efforts are now being made to get more out of the kelp than the potash. Instead of burning the seaweed it is fermented in vats producing acetic acid (vinegar). From the resulting liquid can be obtained lime acetate, potassium chloride, potassium iodide, acetone, ethyl acetate (used as a solvent for guncotton) and algin, a gelatin-like gum.
PRODUCTION OF POTASH IN THE UNITED STATES
| 1916 | 1917 | |||
| Source | Tons K2O | Per cent. of total production | Tons K2O | Per cent. of total production |
| Mineral sources: | ||||
| Natural brines | 3,994 | 41.1 | 20,652 | 63.4 |
| Altmite | 1,850 | 19.0 | 2,402 | 7.3 |
| Dust from cement mills | 1,621 | 5.0 | ||
| Dust from blast furnaces | 185 | 0.6 | ||
| Organic Sources: | ||||
| Kelp | 1,556 | 16.0 | 3,752 | 10.9 |
| Molasses residue from distillers | 1,845 | 19.0 | 2,846 | 8.8 |
| Wood ashes | 412 | 4.2 | 621 | 1.9 |
| Waste liquors from beet-sugar refineries |