Potash Fertilizers

Resources for Potash Fertilizers. Potassium is the seventh most abundant element in the earth s cmst. The raw materials from which postash fertilizer is derived are principally bedded marine evaporite deposits, but other sources include surface and subsurface brines. Both underground and solution mining are used to recover evaporite deposits, and fractional crystallization (qv) is used for the brines. The potassium salts of marine evaporite deposits occur in beds in intervals of haUte [14762-51-7] NaCl, which also contains bedded anhydrite [7778-18-9], CaSO, and clay or shale. The K O content of such deposits varies widely (see Potassium compounds). 

Economic Aspects and Uses. Total world production of potassium products is 29,000,000 tons per year (65). Potassium chloride is removed from brine at Moab, and Wendover, Utah, and at Seades Lake, California. Potassium sulfate is made from Great Salt Lake brine by Great Salt Lake Minerals Corp., which is the largest producer of solar potassium sulfate in the wodd. Combined, these U.S. faciUties stiU produce a relatively small percentage of potash fertilizers in the wodd. Production from the Dead Sea, for example, is 10 times greater than production of potassium from brines in the United States. More than 95% of all the potassium produced is used in fertilizer blends. The remainder is converted to other potassium chemicals for industdal use (see Potassium compounds). 

The major use of potassium sulfates is in agriculture as a fertilizer (97%). The other 3% is used in industry. Potassium sulfate accounts for about 5% of the potash industry. It is twice as expensive as potassium chloride and is only used as potash fertilizer where it performs better than potassium chloride. 

The primary raw materials for nitrogen fertilizers are natural gas, naphtha, fuel oil, and coal. The manufacturing of phosphate fertilizers most often requires phosphate rock. Naturally occurring potassium salts form the basis of the production of most potash fertilizers. 

Potassium losses from soils comprise crop removal, leaching, and erosion. The large potassium output by harvesting in agriculture must be balanced by potash fertilization in the form of potassium chloride or potassium sulfate. Compared with the amount of potassium absorbed by crops, the potassium content of soil solution is small. The potassium content in soil solution is dependent upon the water content of the soil, and can be raised by liming. Plants may remove potassium selectively from the soil solution indeed, during erosion the clay fraction with its high potassium content is selectively removed. 

Almost two-thirds of the world potash production output are exported. All the potash-producing countries except Brazil and China are exporters. Canada is by far the largest exporter (in total, 17 million tons of K2O were exported annually). The estimated world demand for potash fertilizers in the 1990-1991 business year was 26 million tons of K2O, with some 95% of the total potash production being used as fertilizers. The total output of products of the potash industry exceeds requirements by about 1.5 million tons of K2O. 

The concentrations of impurities in manufactured nitrogenous or potash fertilizers are generally low, ranging from 0.1 to 2.0 mg kg (McLaughlin etal.,... 

MOP Muriate of potash (fertilizer-grade potassium chloride) 60%-62%K20... 

Although fertilizer production has decreased drastically in recent years, these markets, especially Eurasia, are rich in raw materials such as natural gas, potash ores, and phosphate rock. Therefore, they will continue to play an important role in supplying nitrogen and potash fertilizers in the global markets. Because Eastern Europe is not as rich in energy resources and raw materials, increased energy costs may reduce its comparative advantage in world fertilizer markets. 

Qose proximity of production facilities to markets is desirable however, the world s ratio of imports to fertilizer use increased from 30 1% in 1979/80 to 38.8% in 1992/93. This indicates that location of basic (N, P, and K) production capacity is increasingly dictated by availability of low-cost raw materials. Some of the reasons for new, emergir centers of production of nitrogen, phosphate, and potash fertilizers are discussed below. 

Skvirski, L. I., A. A. Chistyakov, and Z. L. Kozel. 1991, Production of Non-Dusting and Non-Caking Potash Fertilizers," Presented at Kali 91, 2nd International Potash Technology Conference, Hamburg, Germany, May 26-29. 

This was immediately saleable to feeding-stuffs compounders at a price that started to make the material a product in its own right,not just an effluent disposal credit. In the meantime, the ethanol-spent-wash-ash continued to sell as a potash fertilizer. The next development was the discovery, after much biological testing and long-term feeding trials, that the combined, spray dried residues from both fermentations, if incorporated in the rations of grazing animals, had a... 

Figures 11.14 and 11.15 show DTB crystallizers in two plants for the crystallization of potash fertilizers.

Phosphate fertilizers are derived from rock phosphate and superphosphate which are mined in several areas of the world, e.g. Morocco. Potash fertilizers are again mined directly. Compound fertilizers having specified N P K ratio are also produced. Various ratios are formulated for particular applications. Table 5.1 confirms the very large scale on which fertilizers are produced. 

Fig. 6.16 (a-f) Breakdowns spectra of industrial potash fertilizers with different quantities of Na impurities... 

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