METHOD OF PRODUCING GRANULAR POTASSIUM CHLORIDE Russian patent published in 2014 - IPC C05D1/00 

FIELD: chemistry.

SUBSTANCE: invention relates to agriculture. The method of producing granular potassium chloride includes removing dust from fertiliser in a fluidised bed, conditioning potassium chloride, which contains alkali-earth metal chlorides, with mineral compounds which bind metal ions into nonhygroscopic products, and cooling, wherein conditioning is carried out at a step of filtering the potassium chloride suspension by washing the potassium chloride precipitate with aqueous solutions of the mineral substance, taken in an amount which provides a washing ratio of 0.5-1.5, wherein concentration of the alkali-earth metal in the liquid phase after washing the precipitate is determined using the empirical formula C_k=C_o·ℓ^-Ax, and determining equivalent consumption of the alkaline additive from the obtained concentration of the alkali-earth metal chloride in the liquid phase of the filtered precipitate and content of water therein using reaction equations: Mg²⁺+2OH^-[CO₃ ^2-]→Mg(OH)₂[MgCO₃], Ca²⁺+2OH^-[CO₃ ^2-]→Ca(OH)₂[CaCO₃]. The alkaline additive is dissolved in the washing liquid used to wash the precipitate during filtration thereof from the potassium chloride suspension. The obtained solid phase is dried and granulated.

EFFECT: invention enables to condition potassium chloride which contains alkali-earth metal chloride on the entire volume of the granulated material, and reduces consumption of the alkaline mineral substance.

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