Oxidation process for producing potassium thiosulfate

An efficient process for preparing potassium thiosulfate (K2S2O3) is described. Potassium hydroxide (KOH) and elemental sulfur (S) are converted to potassium polysulfide, which is then oxidized. According to the method, the optimal formula of the required polysulfide can be obtained by using specially designed process conditions such as potassium hydroxide/sulfur molar ratio and temperature, and a specially designed condition set can be used; relatively higher concentrations of a high purity soluble potassium thiosulfate product with relatively low amounts of by-products are obtained, such as temperature, pressure, oxidant rate and duration during oxidation conditions. The manufacturing process may be a batch process or a continuous process using a continuous stirred tank reactor (CSTR). The CSTR process relies on several design parameters, including pressure and temperature optimization to avoid product instability. The resulting potassium thiosulfate is a beneficial fertilizer with high potassium content as