The existing methods of obtaining potassium sulfate are multi-stage, the complexity of the technological scheme, high energy costs, the formation of byproducts of little-used products, and the high cost of the resulting products. In addition to chemical and physicochemical (x-ray phase and scanning electron microscopic methods) analysis to determine the phase composition of intermediate products and finished products and the interaction of the double salt solution with potassium chloride Optimal, economical, waste-free production of potassium sulfate, development of continuous technology is an urgent problem for the republic. The monograph is intended for use by independent researchers, basic doctoral students, research interns, master's and bachelor's students, as well as professionals working in this field in training courses.