METHOD OF PRODUCING POTASSIUM CHLORIDE Russian patent published in 2011 - IPC C01D3/08 

FIELD: chemistry.

SUBSTANCE: invention can be used in processing sylvinite ore. The method of producing potassium chloride from sylvinite ore involves dissolution thereof, crystallisation of the end product from the solution in multiple-step vacuum crystallisers, hydraulic classification of the solid phase with return of fine fractions into the crystallisation loop and filtration of coarse fractions of the crystallisation products. Fine crystalline potassium chloride obtained at the drying and dust elimination step is dissolved to obtain a suspension which is returned to the vacuum crystallisers. The liquid phase obtained after hydraulic classification and filtration of the crystallisation product is further clarified to obtain a clear solution and a thick suspension. The clarified solution is taken for dissolution of sylvinites and the thick suspension is fed into the vacuum crystallisers with addition of water in order to compensate for its loss due to evaporation of the liquid phase during its vacuum cooling from temperature in the receiving tank of the vacuum crystallisers to temperature in the last housing.

EFFECT: invention simplifies the process by cutting the stream of the circulating dissolving solution.

3 cl, 2 tbl, 2 ex