Аннотация
Wide application of extraction phosphoric acid (EPA) is mainly associated with obtaining mineral fertilizers from it. Currently, the main raw material for obtaining EPA is phosphorites of the Kistas deposit. The aim of the work is to purify the plant extraction phosphoric acid (EPA) and obtain liquid N-P-containing fertilizers from it. Results and discussion. The influence of zeolite consumption, time and temperature on the process of acid purification from suspensions was studied. Analysis of the obtained results showed that transparent EPA was obtained regardless of the zeolite rate, duration and temperature of the process. Optimum conditions for the sorption process of EPA purification with natural Shankanai zeolite were determined: S:L = 15:100, ToC – (25-30)oC, τ – 30 min., ensuring complete absorption of suspensions and an increase in P2O5 in EPA by 2.2-2.4%. The process is preferably carried out with a zeolite consumption of 15 g per 100 g of the purified solution. The effect of time on the purification of EFA was studied at constant process factors: temperature - 22 °C and T:L = 1:15 with a process duration of 5 to 90 min. It was shown that in the range from 15 to 45 min, the P2O5 content in EFA increases by (1.59-2.37)% of the initial value. Optimum conditions for concentrating the acid were established: temperature - 40 °C, time - 60 minutes, with the production of EFA with P2O5 (42.90%). Conclusion. For the first time, liquid NP fertilizer was obtained from purified and evaporated phosphorite from Koksu field under conditions of ammonia ammoniation with the ratio N:P=(0.19-0.23):1 and the sum of nutrient components (N+P2O5) equal to (44.15-44.25)%. Optimum conditions for obtaining liquid NP fertilizers were identified: T=25 oC, pH 3.34-3.64.