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potash used in this country was of a lower grade than the 25 per cent crude potash salt mined in New Mexico, and if present conditions continue, a demand may develop for all the available run-of-mine salt. In addition to the large potash plant at Searles Lake, Calif., the two large mines producing from a deposit of sylvite in New Mexico, and a small production from Utah and Maryland, a third mine now under development in New Mexico is scheduled to enter the market this fall, and the resulting increase in production capacity may permit a larger export trade in 1941 to countries cnt off from the European supply. The domestic stock of potassium sulfate and double sulfate is low at present, hut an ample supply by 1941 is anticipated. Within tho last yoar two producers of potassium chloride began the maniifacture of potassium sulfate from potassium chloride, and when the new mine in New Mcxieo reaches t.he production stage, it will provide an additional source of sulfate and also a source of double sulfate of potar sium-magnesia. The seaboard price of potassium chloride, 53.5 cents a
FLOTATION
unit, is the same as before the outbreak of the war, but the price a t Carlsbad is ahout $7 E ton less than a year ago. The prewar price of run-of-mine salt was increased from 58.5 to 60 cents a unit at seaboard to help equalize an increase in freight rates. There is no duty on agricultural potash hut thereisaduty on potash compounds used in industry, and when countervailing duties on imports from Germany were increased in April, 1939, Amcrican chemicd companies reviewed the possibilities of increasing the output of potash compounds in this country. As a result, and particularly since the beginning of hostilitios in Europe, facilities for the production of the chlorate, nitrate, hydroxide, cyanide, and other potassium compounds have been enlarged or, in some instances, new plants have boen constructed. The extent of the manufacture of potash compounds in this country is indicated by the consumption last year of approximately 50,000 tons of potassium chloride for other than agricultural purposes. Pas~zsamoby permission of the Direotor. United States Ceolo~ioalSurvey.
BRUNN D E W Y , American Cyanamid Company. New York, N. Y.
ODAY by far the largest part of the nonferrous metals which are used by industry, and especially those indue tries engaged in producing materials vital to national defense, are smelted and refined from concentrates produced by the chemical froth-flotation process. The most important of these nonferrous metals arc, fronr the tonnage standpoint, copper, lead, zinc, and molybdenum. During the first World War, concentrates of these metals which were delivered to the smelters and refineries by the mining companies were produced by gravity concentration
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VOL. 32, NO. 9
or the then new and as yet not widely used oil bulk-flotation process. The oil hulk-flotation process, while a great improvement over gravity concentration methods for many ores, was soon superseded by the improved chemical frothflotation process. The main difference between the oil bulk method and the chemical froth method is the substitution, for the crude insoluble oils which acted as collectors in the former process, of frothers of the pine oil and cresylic acid types, water-soluble promoters of the xanthate and dithiophosphate types, the use of depressors, such as oya-
SEPTEMBER, 1940
INDUSTRIAL AND ENGINEERING CHEMISTRY
nide, for unwanted minerals, and conditioners, such as alkalies. It is now possible to produce concentrates by the chemical froth-flotation process from ores which i t was not economical to treat by gravity methods or by oil bulk-flotation methods. Therefore, the chemical froth-flotation process is recognized as probably the most important factor which has enabled the metal industry to keep its production in line with the large increase in consumption of base metals in the last twentyfive years. The reagents use I in the chemical froth-flotation process are very efficient, and only small quantities are required to effect economic recovery of the minerals. Promoters are often effective when used in amounts as small as 0.05 pound per ton. I n many cases frothers are as efficient, although in general, more frother is needed than promoter.
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The frothers and promoters mentioned above are not the only ones used in the froth-flotation process. Complex and certain types of ores often require special chemicals. It is also possible in many cases to substitute one reagent for another with nearly the same results, The mining industry is not dependent upon manufacturers abroad for flotation chemicals, since chemical companies engaged on this side of the water in the production and distribution of chemical flotation reagents have the facilities to supply any demand for these products brought about by increased production of concentrates from the froth-flotation process. Mining companies employing the froth-flotation process need have no worry that they will be unable to get prompt delivery of the flotation reagents they need for any expansion program they have in mind.
CANNING INDUSTRY c. 0. BALL, American Can Company, New York, N. Y.
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N AN ADDRESS before the Institute of Food Technologists on June 19, 1940, Assistant Secretary of War Johnson indicated the importance of the canning industry in a defense preparedness program. A suggestion as to the role to be played was contained in a few statistics pertaining to the Army alone. The American Expeditionary Forces in France during the first World War consumed 200 million cans of evaporated milk, 150 million cans of corn, peas, and string beans, 190 million cans of tomatoes, 50 million cans of salmon, and 750 thousand cans of sardines-to mention a few items. Secretary Johnson omitted stating how many cans of numerous other important items were consumed-for example, corned beef, bacon, butter, coffee, and even candy. h’or did he say how much, was consumed by the mobilized forces at home. An army of 2 million men, which is said to be planned for muster by October, 1941, will consume a large quantity of canned food but not enough to disrupt the normal tenor of an industry that produces annually from 12 to 15 billion cans of food and is capable of producing much more. The capacity of canning plants is considerably greater than that demanded for annual production equal to that of 1939. Statistics show that the pack of staple vegetables and fruits last year was only about 75 per cent as large as that of 1937; and it is safe to say that even the 1937 pack did not tax available facilities to capacity. Nevertheless, in the course of the preparedness program, expansion of facilities might be necessary. An expansion program presents no difficult problems, except as it is accompanied by the possible exigencies of war. It is on the assumption that war conditions will exist that serious aspects develop and must be considered in the problems, chemical and otherwise. AGRICULTURAL PROBLEMS. Considering the industry from the standpoint of a flow plan, the first problems arise in the agricultural phase. The matters of agricultural machinery and seeds will be passed over with the comment that their supply is not dependent on the destinies of our foreign commerce. The same may be true with respect to insecticides and fungicides. To a considerable extent substitutions are possible in this field. Production in unlimited quantity of rotenone, the insecticide most commonly used on canning crops, is possible by the growing of the derris plant.
The fertilizer supply at present is not entirely of intranational origin, notwithstanding the message that came from the Sixteenth Annual Convention of the National Fertilizer Association, June 3 to 5, stating that the fertilizer industry’s capacity is sufficient to meet the demands of United States’ farms a t reasonable cost. This statement applies t o peacetime conditions. While the importation of chemical nitrogen, phosphates, and potash, as well as of natural organics has decreased materially during the past decade, imports are still considerable. The outlook with respect to fertilizing materials, however, is bright, A Congressional investigating committee last year estimated that our domestic phosphate reserves are sufficient to last for at least 3000 years a t the present rate of consumption. Supplying from domestic sources all demand for phosphorus does not appear to present a serious problem. Perhaps improvements at TVA already recommended by the Stettinius committee of the Advisory Commission on National Defense will take care of this matter. The Bureau of Mines recently announced that, as a result of operations undertaken in California and New Mexico, domestic potash productive capacity is now considered sufficient to meet domestic demands. Production could no doubt be increased readily to meet emergency demands. Increased use of blast furnace coke in steel production means increased production of ammonium sulfate; and together with the potential increase in the production of synthetic ammonia, this gives promise that emergency requirements of nitrogen can be met. However, the major demand for nitrogen will not be for fertilizer but for high explosives. I n case demand grows too rapidly to be met by domestic production, i t is expected that the first stages of war will not shut off the supply of nitrates from Chile, whence our reserve supply is now being enlarged as rapidly as possible under direction of the Advisory Commission on Sational Defense. Augmented production of organic fertilizers, of course, can help to supply the increasing demands. CANNIXG PLANTS.Expansion in food canning capacity is not a long-term proposition. Buildings suitable for canning operations can be quickly constructed, as can also the ordinary machinery for canning, which, in general, is not of complex design and construction.
