Process for separation of insoluble residue from hydrochlorophosphoric acid pulp
Abstract
Due to the shortage of phosphorus fertilizers, hydrochloric acid processing of phosphorites of the Central Kyzylkum (CK) by the method of separating the insoluble residue (i.r) is of great importance for the production of fertilizer precipitate. The use of the chemical energy of this acid to produce precipitate will improve the technical and economic indicators of the processes of obtaining chlorine-free fertilizers. Fertilizer precipitate can be produced from the phosphate waste of thermal enrichment of CK phosphorites and hydrochloric acid. Taking into account phosphate fertilizers' drawbacks can be solved and expanding the range of mineral fertilizers. In addition, the study of the elemental and salt composition of insoluble residues makes it possible to determine the area of its application. The paper describes the study of the separation process of insoluble residue and the establishment of their elemental and salt composition by modern physicochemical methods. For washing the insoluble residue, water was taken in the ratio of phosphate raw materials: H2O=1.0: 0.1; 1.0 : 0.2; 1.0 : 0.3; 1.0 : 0.4; 1.0 : 0.5; 1.0 : 0.6 at a water temperature of 80-90°C. According to the analysis results, an insoluble residue of the following composition was obtained: P2O5total. - 5.05-7.80%; CaOtotal - 11.86-16.25; SiO2 - 44.28-48.60%; Cl - 2.55-4.25%; Al2O3 - 6.32-7.16%; Fe2O3 - 5.26-6.01%; SO3 -7.15-8.61% from the mineralized mass (MM) and P2O5total. - 4.78-7.38%; CaOtotal -12.51-17.15; SiO2 - 43.57-46.52%; Cl - 2.71-4.48%; Al2O3 - 4.95-5.61%; Fe2O3 - 3.66-4.18%; SO3 -4.93-5.94% from phosphorite powder (PhP).