Phosphate fertilizers consumption

Between 1970 and 1978, U.S. sulfur demand grew from 9.2 to about 12 million long tons per year, equivalent to an average annual rate of increase of about 3.4 percent. Over the forecast period, we anticipate an average annual increase of about this same rate. Our estimate assumes that the U.S. will continue to maintain world leadership as an exporter of upgraded phosphates, and that growth in domestic phosphate fertilizer consumption will average about 3 percent per year. 

Worldwide, triple superphosphate, over the period 1955 to 1980, maintained about a 15% share of the phosphate fertilizer market (Fig. 8). World consumption for the year ended June 30, 1991 (9) was equivalent to 3.6 x 10 t of P20, which was about 10% of world fertilizer P2O5 consumption. In the United States, consumption for the year ended June 30, 1990 (Fig. 7) was equivalent to about 240 x 10 t of P20, which represented only 6% of U.S. fertilizer P2O5 consumption. 

Monoammonium Phosphate. Monoammonium phosphate [7722-76-1] (MAP), NH4H2PO4, has become second only to diammonium phosphate as a phosphate fertilizer material of trade. During the year ended June 30, 1990, monoammonium phosphate used ia the United States furnished 985 thousand t of P2O5 as compared to 1.5 million t furnished by diammonium phosphate and 240 thousand t by triple superphosphate (Fig. 7). Monoammonium phosphate furnished 25% of total P2O5 consumption. 

Agriculture is the largest industry for sulfur consumption. Historically, the production of phosphate fertilizers has driven the sulfur market. Phosphate fertilizers account for approximately 60% of the sulfur consumed globally. Thus, although sulfur is an important plant nutrient in itself, its greatest use in the fertilizer industry is as sulfuric acid, which is needed to break down the chemical and physical stmcture of phosphate rock to make the phosphate content more available to plant life. Other mineral acids, as well as high temperatures, also have the abiUty to achieve this result. Because of market price and availabiUty, sulfuric acid is the most economic method. About 90% of sulfur used in the fertilizer industry is for the production of phosphate fertilizers. Based on this technology, the phosphate fertilizer industry is expected to continue to depend on sulfur and sulfuric acid as a raw material. 

The need for acid concentrators exists because many uses of sulfuric acid do not lead to its consumption. Instead, the acid is diluted and partially degraded and contaminated. In the past, large amounts of acid were disposed of either by usiag it ia the phosphate fertilizer iadustry to dissolve phosphate rock or by neutralization and subsequent discharge to waterways. 

Historically, consumption of sulfuric acid has been a good measure of a country s degree of iadustrialization and also a good iadicator of general busiaess conditions. This is far less vaUd ia the 1990s, because of the heavy sulfuric acid usage by the phosphate fertilizer iadustry. Of total U.S. sulfuric acid consumption ia 1994 of 42.5 x 10 metric tons, over 70% went iato phosphate fertilizers as compared to 45% ia 1970 and 64% ia 1980 (144). Uses other than fertilizer have grown only slowly or declined. This trend is expected to continue. Production and consumption trends ia the United States are shown ia Tables 9 and 10. 

The global demand for food stimulated increased fertilizer usage and consequently increased phosphate rock consumption through 1990. Over the last decade, rock production has been somewhat flat. Although production capacity has declined in the United States, new mine capacity has been added elsewhere. From Table 23.3 it is evident that significant increased phosphate rock production capability has been added in Morocco, China, Tunisia, Jordan, and the countries comprising Other. 

Because of the low P content (usually < 0.2 %) of forage plants, P supplementation is commonly practiced in most ranches throughout the Amazon basin, particularly in Brazilian Amazonia. Assuming a stocking rate of 0.8 animal units per hectare per year, the annual input of P to the system through animal consumption of mineral supplementation would be around 2.0 kg, which is close to the amount expected to be exported annually by animal products (2.5 kg). The amount thus needed to balance the cycle would be only 0.5 kg. In the absence of phosphate fertilizer inputs, this P must come from the soil pool reserves, through forage consumption. 

Detergent consumption included in phosphate fertilizer category. 

The worldwide consumption of phosphate fertilizers in 1997/98 was >30x10 tons phosphate, with about 20x10 tons being used in developing countries. In comparison, 80x10 tons of nitrogen fertilizers were used worldwide. Asia has the highest production and also consumption of phos-... 

Ground phosphate rock is not classified as a fertilizer in most countries and is not included in fertilizer consumption statistics reported by most countries. However, FAO reports consumption of ground rock phosphate separately in 1976 reported consumption was... 

U.S. consumption of sulfur is about 12 million t/yr. For a relative comparison, a 1,000 MW IGCC power plant would produce about 70,000 t/yr sulfur (assuming a 3 weight percent (wt%) sulfur feed coal, 65% annual capacity factor, and 99% sulfur recovery). About 80% of this sulfur is converted to sulfuric acid in the production of phosphate fertilizer. Fertilizer demands for sulfur are expected to increase with time as world food demand increases. U.S. phosphate fertilizer production centers in Florida, which has large supplies of phosphate rock. 

Phosphorus, in addition to nitrogen and potassium, is an essential ingredient of modern high analysis fertilizers. An ever-increasing global demand for food has resulted in increased fertilizer use and increased phosphate rock consumption. The data presented in Table 10.2 show a marked increase in world phosphate production, equivalent to an annual growth rate of 3.5 percent from 1970 to 1989. 

States during the 1980s are given in Table 14.5 for major acid-producing states. The South accounts for about 75 percent of new sulfuric acid production, most of which is captive consumption for phosphate fertilizer production. With its massive phosphate rock deposits, Florida leads the nation in sulfuric acid production, to feed its phosphoric acid plants. Sulfur mines and recovered sulfur from oil and gas operations in Texas and Louisiana provide brimstone feed to sulfuric acid plants. Many of these plants are sited near major waterways to provide cheap transportation for raw materials and fertilizer products. Southwestern sulfuric acid plants usually are associated with smelters that ship the acid by rail to fertilizer plants. 

Eig. 7. Routes for making finished fertilizer from mineral phosphate. Consumption data are for year ending June 30, 1990 (5). includes quantities appHed... 

Ammonia synthesis is the second largest chemical process, after the production of sulfuric acid (see also Chapter 1). It accounts for about 1 % of the total human-related energy consumption. Roughly 80 % of the ammonia produced is used for fertilizers (either as liquid ammonia or as more easily handled salts such as ammonium nitrate, ammonium phosphate, etc.) and, as such, ammonia synthesis is indispensable for our society. Other applications of ammonia are nitrogen-containing... 

The world s phosphorus consumption is in the order of 40 m.t.p.a. (as P 0 ). About 90% of this involves the fertilizer industry (1). The primary natural source of phosphorus is rock phosphate the major chemical produced from it is phosphoric acid. 

Among the deleterious materials (Fc203, AI2O3, CaO, MgO) in phosphate rock, dolomite is the most troublesome. Dolomite causes higher consumption of sulfuric acids, reduces filtration capacity, and lowers the P2O5 recovery in fertilizer manufacturing. Therefore the MgO content is a very important index in evaluating the quality of the phosphate concentrate, hi Florida, the MgO in the final phosphate concentrate is usually required to be less than 1%. 

Essentially all fertilizer phosphorus now is derived from mined ores. (The occurrence, mineral characteristics, mining, and benefici-ation of major phosphate ores were described in some detail in Chapter 23.) Worldwide, about 85 percent of the mined phosphate eventually finds its way into fertilizer.3 As mentioned earlier, the most conservative estimates indicate a sufficiency for hundreds of years at expected consumption levels. Supply problems of the immediate future will relate chiefly to exhaustion of the better ores, with the result that ores of lower grades and higher impurity contents will have to be processed. 

More than 90% of world sulfur consumption is used in the production of sulfuric acid, much of which goes to the fertilizer industry. Smaller amounts of sulfur are used in the manufacture of gunpowder, matches, phosphate, insecticides, fungicides, medicines, wood, and paper products, and in vulcanizing rubber. Despite slight uncertainties in sulfur demand in the 1990s, its use is still predicted to grow. 

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