Ammonium phosphates economics

The purpose of this chapter is to describe the technology and economics of production of nitric acid and nitrates (except potassium nitrate, which is covered in Chapter 15) and the production of ammonium salts for fertilizer use (other than ammonium phosphates, which are covered in Chapter 12). The chapter also includes nitric acid and nitrate technologies developed in Russia and other countries of Eastern and Central Europe. The Commonwealth of Independent States (QS) was the largest producer of nitric acid, nitrates, and other fertilizers in that area [1,2,31, and all original technologies in the CIS were developed solely by the State Institute of Nitrogen Industry (GIAP). 

The popularity of ammonium phosphate fertilisers arises from their high nutrient content of both P and N, high solubility and good storage and handling characteristics. They are easy to produce and compete economically with the longer-established calcium salts. Commercial products are available as solutions, solids or suspensions. 

An additional mole of ammonium sulfate per mole of final lactam is generated duting the manufacture of hydroxylamine sulfate [10039-54-0] via the Raschig process, which converts ammonia, air, water, carbon dioxide, and sulfur dioxide to the hydroxylamine salt. Thus, a minimum of two moles of ammonium sulfate is produced per mole of lactam, but commercial processes can approach twice that amount. The DSM/Stamicarbon HPO process, which uses hydroxylamine phosphate [19098-16-9] ia a recycled phosphate buffer, can reduce the amount to less than two moles per mole of lactam. Ammonium sulfate is sold as a fertilizer. However, because H2SO4 is released and acidifies the soil as the salt decomposes, it is alow grade fertilizer, and contributes only marginally to the economics of the process (145,146) (see Caprolactam). 

Phosphate-polymer control, in industrial water treatment, 26 132-133 Phosphate recognition, 16 794 Phosphate refractory dental dies, compressive strength, 8 289t Phosphate rock, 11 119, 120 minerals in, 19 5, 14 recovery of fluoride from, 14 12-13 U.S. imports for consumption of, 19 15t U.S. production of, 19 17 Phosphates, 18 814-863 19 19. See also Phosphate Polyphosphates aluminum acid, 18 839 ammonium, 11 487 18 835-836 analysis of, 18 851-852 calcium, 18 836-839 condensed, 18 841-852 crystalline, 18 839 dispersants, 8 710t economic aspects of, 18 859-860... 

U.S. production of sulfuric acid in 2001 was 40.1 million tons, far exceeding that of any other chemical (Table 19.1). It is used mostly to manufacture soluble phosphate and ammonium sulfate fertilizers, but it is essential to many other industries (Figure 19.12). So widespread is the use of sulfuric acid in industrial countries that the amount produced is sometimes regarded as an indicator of economic activity. 

Sewage treatment has both ecological and economical importance. Ammonium and phosphate ions are the primary inorganic contaminants in municipal wastewater and these ionic compounds are responsible for the phenomenon of eutrophication. In common sewage treatment, ammonium is removed by biological denitrification and phosphates are precipitated with the help of aluminum and iron salts [56], However, the use of low-cost natural zeolites has been found promising for... 

The main use of nitric acid is in the preparation of inorganic and organic nitrates. It is also rapidly replacing sulphuric acid in the acid treatment of phosphate. Its uses are shown in Table 3.9. Because of its efficient production from increasingly inexpensive ammonia it has become one of the most economically valuable acids. In combination with ammonia it is readily converted to ammonium nitrate. 

Several systems have been patented for removal of the unreacted ammonia from the crude product gas. The early Andrussow processes used dilute sulfuric acid ( 6%) as absorbent and produced ammonium sulfate as a by-product. However, the high cost of processing this material has made it increasingly difficult to compete in the already oversupplied fertilizer market. Unless there are special circumstances, present economics and environmental considerations favor the use of a recycle system to recover the unconverted amonia. The typical ammonia recovery systems use monoammonium phosphate at 80°C as the absorbent to react with the unconverted ammonia in the crude product gas to form diammonium phosphate. The diammonium phosphate solution then undergoes a thermal reversal process to liberate ammonia for recycle. The regenerated monoammonium phosphate solution is reused in the absorption system. Polyhydroxyboric acid complex is an alternative absorbent for ammonia recovery that works on the same principles. 

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