Graphic Study of the Dihydrate–Hemihydrate Process for the Synthesis of Phosphoric Acid According to the Diagram of the CаO–P2O5–SO3–H2O System

Abstract

A graphic analysis of the processing of phosphorites from Koksu (Karatau deposit) into extraction phosphoric acid (EPA) by the dihydrate–hemihydrate method was performed according to the equilibrium solubility diagram of the CaO–P₂O₅–SO₃–H₂O system. It was shown theoretically that EPA with 30.0% P₂O₅ can be obtained for practical purposes from common phosphate raw material of Koksu (24.5% P₂O₅). The main concentration and mass parameters that underlie the experiments on process development were evaluated.