IMPROVEMENT OF THE PRODUCT COMPOSITION FROM NITRIC ACID PROCESSING OF KYZYLKUM CARBONATE PHOSPHORITES

Section: Articles Published Date: 2024-11-16 Pages: 47-58 Views: 0 Downloads: 0

Authors

  • Ayjamal Allamuratova Associate Professor, Karakalpak State University, Named After Berdakh, Uzbekistan
  • Aktam Erkaev Professor, Tashkent Institute Of Chemical Technology, Uzbekistan
  • Akhmed Reymov Professor, Karakalpak State University. Named After Berdakh, Uzbekistan
  • Kazakhbaev Saparbay Basic Doctoral Student, Karakalpak State University. Named After Berdakh, Uzbekistan
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Abstract

The process of producing NP-fertilizers by nitric-sulfuric acid decomposition of phosphate rock (17.20% P2O5) under thickening slurry conditions has been studied. It was shown that the higher the recycle ratio, the lower the moisture content of the final product. Increasing the HNO3 dosage above 30% and H2SO4 above 70% is undesirable, as the product's moisture content exceeds 6.03% and it has increased acidity. To avoid issues during ammoniation, an optimal rate of nitric and sulfuric acid was proposed—73.5-91%, which produced products containing 9.34-10.61% -P2O5total; 3.04-4.54% N; P2O5 digestive:P2O5 total = 73.4-82.3%; pH = 3.3-3.6, and granule strength of 2.1-2.3 MPa. The process of producing NPK-fertilizers was also studied by adding nitrogen components such as K2SO4, KCl, and K2CO3 to the products of complete nitric acid decomposition of washed and dried concentrate (24.10% P2O5) and fine fractions (18.55% P2O5). The process includes decarbonization and decomposition of the phosphate raw material (simultaneously in one apparatus), neutralization to a pH not lower than 3.5, evaporation of the slurry to a density of at least 1750 kg/m3, the addition of potassium salts at N:P2O5:K2O ratios of 1:1:1, 1.5:1:1, and 1:1.5:1, product granulation, drying in the presence of recycle, and cooling.

Keywords

Phosphorites of Central Kyzylkum and Karakalpakstan, inorganic salts, activation