hemistry, Fertilizer Chemistry, and Industrial and Engineering Chemistry t the 114th Meeting of the American Chemical Society, Washington, D. C.
Evolution in Fertilizer Phosphate Industry VINCENT SAUCHELLI THE DAVISON CHEMICAL CORPORATION,BALTIMORE 3, MD
T h e author traces the evolutionary process in agriculture from the middle of the 19th century to the present time. The causes of this evolutionary procesa am discussed. The depletion of soil fertility by growing crops was a major impetus in the evolution and development
of the fertilizer industry. Coincidental with this were the evolution and development of the phosphate business. Methods of producing superphosphate are discussed as am the technological changes in the exploitation of the rock phosphate deposits.
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mechanical, and political. There are other causes, of coume. Evolution is merely the resultant of this constantly interaoting complex of forces. One of the decisive forces which has brought about evolutionary changes in agriculture is the recognition through soil science that soil fertility is constantly being depleted by growing crops. This is of major significance in the evolution and development of the fertilizer business. And that involves the phosphate business.
HE fertilizer phosphate business is involved in a group of very complex phenomena fitly described by thephrase, agncultural evolution. This evolutionary process is something that cannot be stopped. To adjust oneself to this contiiuous change is to be wise and successful; to oppose it is to'invite failure. Agriculture deals with living matter. It is a biological industry dealing with dynamic forces-plant+ animals, microorganisms, and weather. Life is synonymous with change. Hence, trenh in agriculture drive inevitably towards change. Lgriculture ibelf is impelled by an ever-changing complex of biological, economic, and social forces. By looking back over the past century from the time when Liebig first published his famous book and when Lawes in England first produced superphosphate, one can follow the evolutionary process in agriculture by certain outstanding developments. The process operates at an accelersting rate, l i e a falling bodyslow at the beginning of the 19th century, it starts to gain speed about 1850 and by 1900 it is traveling a t B fast pace. As WBS to be expected, the influence of the industrial revolution and allied factors speeded up the general tempo of civilization of this period and the speed of agriculture inevitably was accelerated by these developments. Speed seems to generate desire for more speed. What is the basic cause of this evolutionary process? A t least one of the causes is modern science-chemical, biological,
HISTORICAL classic studies inI n 1840 Justus van Liebig published volving the influence of chemistry on agriculture and physiology. That was the first reasonable interpretation of the interrelations of soil minerals, animal manures, light, sir, and moisture. He showed the feasibility of supplying calcium and phosphates to growing plants by means of ground bones. He ww also the first to point out that sulfuric acid added to the ground bones gave a form of phosphate more quickly available to plants than raw bone. The vision and business acumen of John Bennett Lawes led to the commercial development of available phosphates by treating an inorganic phosphate compound with sulfuric acid. By 1862, just 20 years after Lawes received his patent, the United Kingdom 1314
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INDUSTRIAL AND ENGINEERING CHEMISTRY
was producing 150,000 tons of superphosphate. Commercial development continued a t an accelerated speed. By 1942 the world produced about 16,000,000 metric tons of superphosphate having an average of 17% phosphorus pentoxide. Our country alone, in the fiscal year which ended June 30, 1947, produced close tg 10,000,000 tons of superphosphate, 18% equivalent. Since 1850 superphosphate has formed the basis of the world’s commercial fertilizer industry. It continues t o be the premier source of phosphoric acid for agricultural use in nearly all countries. Prior to 1850 the principal commercial fertilizer was bone dust-the chief form of calcium phosphate known up t o that time. According to the Census Bureau (1) the manufacture of chemical fertilizers in the United States was begun in 1850 by William Davison and P. S. Chappell in Baltimore. For B number of years Baltimore remained the leading chemical fertilizer center of the country. The first domestic superphosphates were made in Baltimore, which remains to this day one of the country’s leading producers of superphosphates. From 1850 on the fertilizer industry grew steadily, and, parallel with it, the phosphate industry. In 1910, the United States consumed about 5,500,000 tons of commercial fertilizer. In that same’ year 2,600,000 tons of rock phosphate and 2,900,000 tons of superphosphate were marketed. By the end of 1947, the total domestic production of commercial fertilizer was almost 17,000,000 tons, rock phosphate about 10,000,000 tons, and superphosphates 18%basis about 10,000,000 tons. The annual retail sales value of commercial fertilizer in this country is about $600,000,000-a huge figure by any standard. ROCK PHOSPHATE DEPOSITS The remarkable growth of the domestic phosphate industry is based on the discovery and development of extensive deposits of rock phosphate in this country. The first development of deposits occurred in South Carolina in 1867. Charleston quickly became an important producer of superphosphate, and by 1870 had seven manufacturing companies. Deposits were next discovered in Florida and in 1888 that state shipped its first 3000 tons. Other discoveries followed in Tennessee, Montana, Idzho, and Wyoming. This country has the world’s biggest reserves of phosphate rock, estimated a t over 14 billion tons. This total is greater than the reserves of all the rest of the world and almost twice as big as the next largest reserves which lie in Russia. PROCESS DEVELOPMENTS The “wet” method of produring superphosphate described by Lawes has dominated the field because of its simplicity and economical operation. The criticism that the industry has made little technological progress in over a century of existence is unjust. The industry has kept pace with requirements. In recent years “dry” or furnace methods of preparing phosphates for industrial and agricultural uses have received increasing consideration from engineers and processors. Since superphosphates are produced and used in many countries, engineers in each country have evolved a technology conforming to local economics. The greatest changes have occurre 1 in the last quarter century. Prior t o World War I the fertilizer industry commonly used unprocessed materials of low analysis, superphosphate and ammonium sulfate were the principal processed product&in use. Subsequently new processes and products of higher plant nutrient content entered the trade, old processes were improved, and the modern trend to utilize engineering principles in the fertilizer works took on an accelerated pace. In this progress private organizations and governmental agencies combined forces for the common good of the farmer. Significantly, the rate of progress was stimulated by knowleddr derived from fundamental chemical studies. The chemical composition of natural phosphates revealed that fluorine is a con-
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stituent of rock phosphate and research into the influence of this element on the properties and chemical behavior of rock phosphate established the bases for new processing techniques, particularly in thermal processes. Another development of far-reaching influence on industry practices was concerned with reactions of free ammonia and superphosphate. Within 10 years of the first commercial use of this information, anhydrous ammonia and ammonia solutions comprised more than 30% of the total domestic nitrogen used in fertilizer manufacture. This use is bound to increase because of its many practical advantages, not the least of which is lower nitrogen cost t o the farmer. PRESENT TRENDS The trend a t present is t o produce fertilizers and fertilizer materials of higher plant nutrient content. Considerable research is also being carried out on different carriers of phosphorus. Illustrative of this trend are the developments in concentrated superphosphates of 45 to 50% available phosphorus pentoxide by the wet and furnace processes; calcium metaphosphate with 61% phosphorus pentoxide; fused tricalcium phosphate of 26 to 30% phosphorus pentoxide; phosphoric acid from elemental phosphorus or furnace gases; elemental phosphorus by the electric furnace; dicalcium phosphate for animal feed; diammonium phosphate, with 54% phosphorus pentoxide and 21% nitrogen; monoammonium phosphate with 11% nitrogen and 48% phosphorus pentoxide; studies in the production of phosphatic materials by means of nitric in place of sulfuric acid; and the use of continuous operation as opposed t o batch operations in the fertilizer works. ROCK PHOSPHATE INDUSTRY The rock phosphate industry has made enormous gains in the efficiency with which it exploits the deposits. Labor-saving technological changes have marked this progress. New methods and new types of equipment plus an increase in the capacity and efficiency of the equipment are chiefly responsible for the increase in output per man. The production of phosphate rock started as a pick and shovel and wheelbarrow operation aided by mule-drawn scrapers and wagons in 1880. The operation changed steadily to the use of steam shovels, 7.ailroad haulage, and hydraulic monitors which throw streams of Rater of 100 t o 150 pounds of pressure to break up the overburden and matrix, then to the use of draglines in the Florida and Tennessee fields equipped with booms up t o more than 170 feet in length and with buckets of 4 to 16 cubic yards capacity. One of these huge draglines in Florida will remove about 10 tons of overburden every 40 or 50 seconds of actual operating time and up t o about 1500 tons per hour. This is about 6 times the amount accomplished with steam shovels and draglines about 25 years ago. And usually only 3 men are required per shift to operate one of these electric giants as compared with 30 to 40 men needed to carry out the same operation in the earlier steam shovel and locomotive period. A significant recent development is the increase in production and marketing of phosphate rock in the intermountain region. In 1920, the combined total production of rock from Idaho, Montana, Utah, and Wyoming amounted to 60,000 long tons; in 1940, to 180,000 long tons; and in 1947 to 1,200,000 long tons, valued at the mines a t $6,000,000. In the same period Florida increased its production from 3,700,000 long tons in 1920 to 6,500,000 long tons in 1947. Chiefly because of Army shipments to Japan, more rock was exported in 1947 from the western states than from Florida. LITERATURE CITED (1) Munroe, C. E., and Chatard, T.M., U . S . Census, 10,Part 4,562 (1900). RECEIVED August 26, 1948.
