Abstract
The article presents the research results on obtaining the highly effective complex fertilizer sulfoammophos based on wet-pprocess phosphoric acid of various concentrations. This product is not produced in Kazakhstan; to launch it at the Mineral Fertilizers Plant, it is necessary to study the effect of acid concentration and soluble impurity content on obtained fertilizer composition. Standard chemical and instrumental methods of analysis were used to identify the obtained salts. It was found that when evaporating wet-pprocess phosphoric acid in precipitator presence the fluorine content decreases several times. The most intensive reduction in content of other impurities in the acid occurs with soda ash introduction due to their binding in the form of insoluble precipitates of sodium silica fluoride and isomorphic complex compounds of aluminum, iron and calcium. By ammonization of defluorinated wet-pprocess phosphoric acid solutions of concentrations of 25-31% P2O5, sulfoammophos samples were obtained that meet the standard requirements in terms of sulfur and nitrogen content, and even exceed the standard values in terms of phosphorus. The effect of wet-pprocess phosphoric acid concentration on the crystal size and moisture content of sulfoammophos was studied; the optimal acid concentration for obtaining a high-quality product was determined. Sulfoammophos obtained on the basis of evaporated wet-pprocess phosphoric acid of concentration of 25-26% P2O5 is ballast-free concentrated water-soluble complex NP(S) fertilizer.