OPTIMAL AMOUNTS AND CONCENTRATIONS OF CALCIUM NITRATE SOLUTION IN THE PRODUCTION OF PHOSPHATE FERTILIZERS

Abstract

 The effect of the quantity and concentration of calcium nitrate solutions on the qualitative parameters of fertilizer precipitates obtained on the basis of mineralized mass (MM) was studied. For laboratory experiments, we used MM with the following composition (wt.%): 14.60 - P₂O₅, 43.99 - CaO; 14.11 - CO₂, 1.58 - SO₃; 10.82 - n.d .; CaO: P₂O₅ = 3.01. The optimal ratios and concentrations of calcium nitrate were determined: the ratio of MM : solution Ca(NO₃)₂ = 1 : 2.0 and the concentration of calcium nitrate solution - 10 and 15%. With optimal parameters, a fertilizer precipitate of the following composition (wt.%) Is obtained: P₂O_5total. = 23.60-23.68; P₂O_5ac.c.a.. by citric acid = 12.67-12.72; P₂O_{5water solubility} = 2.10-2.11; СaO_total. = 43.36-43.39; СaO_ac.c.a. by citric acid = 24.19-24.24; СaO_{water solubility} = 4.24-4.35; N = 1.77-1.82. The degree of removal of Ca(NO₃)₂ from fertilizer precipitates is 97.07-97.42%. This produces the main filtrate containing 20.70-22.52% Ca(NO₃)₂.