Production of potassium sulphate from naturally occurring sodium sulphate and potassium chloride

The production of potassium sulphate from sodium sulphate and potassium chloride is recognized as a two stage operation. In the first stage sodium sulphate and potassium chloride react to form glaserite‐a double salt of sodium and potassium sulphate. In the second stage glaserite reacts with potassium chloride to form potassium sulphate. The re‐use of mother liquor from stage two and the recovery of potassium chloride and sodium sulphate from stage one are important aspects of the problem. The efficiencies of the various operations in the process have been improved by fairly extensive use of phase data which are mainly available in the literature.