Electrodialysis Metathesis for the Production of Potassium Phosphate.

Potassium phosphate (KPO) is a common inorganic compound with broad applications in agriculture and industry. Although the traditional thermal method of preparing KPO by reacting phosphoric acid with potassium hydroxide can obtain high-quality products, it consumes a lot of energy and has high costs. This study explores the process of preparing KPO by Electrodialysis metathesis (EDM). This process uses sodium phosphate (NaPO) and potassium chloride (KCl) as raw materials and can prepare KPO continuously. Under the optimized conditions (operating voltage of 8 V, 0.35 mol/L NaPO and 1.05 mol/L KCl in raw flow with the rate of 30 mL/min), the product purity of KPO reaches more than 97%, the energy consumption is 1191 kW·h/t, and the cost is about 8314 CNY/ton. Compared with traditional methods, EDM has the advantages of low cost, simple operation, and high utilization rate. This study shows that EDM technology has significant potential in preparing KPO.