METHOD OF PROCESSING SALT SOLUTION WASTES CONTAINING A MIXTURE OF SULPHATES AND NITRATES OF AMMONIUM AND SODIUM Russian patent published in 2020 - IPC C01D5/06 C05D1/00 C05D5/00 C05G3/00 C01D9/08 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical technology for processing wastes of salt solutions for producing mineral fertilizers and sodium chloride. Method of processing salt solution wastes containing a mixture of ammonium sulphates and nitrates, includes conversion of salt solutions with potassium chloride, evaporation of solutions and separation of salt products, wherein before conversion saline treated enriched carnallite KClMgCl₂⋅6H₂O and a solution of sodium hydrogen phosphate Na₂HPO₄, to obtain struvite MgNH₄PO₄⋅6H₂O, adjusted to pH values of 8.0–9.5 due sodium hydroxide, struvite is washed and processed into complex NPMg-fertilizer of prolonged action, and the solution obtained after separating the struvite is treated with crystalline potassium chloride, evaporated and a glaserite precipitate is recovered, the mother solution is evaporated after separation of glaserite and sodium chloride is extracted therefrom, remaining saline solution is subjected to vacuum crystallization and potassium nitrate is separated from it, which is mixed with glaserite and processed into a chlorine-free complex NKS-fertilizer.

EFFECT: invention enables to obtain complex NPMg-fertilizer (struvite), NKS-fertilizer and sodium chloride used as the main component of an anti-icing agent.

6 cl, 1 ex