METHOD FOR PRODUCING NITROGEN-POTASSIUM SULFATE FERTILISER AND HYDROCHLORIC ACID Russian patent published in 2017 - IPC C05D1/02 C01D5/02 

FIELD: agriculture.

SUBSTANCE: method for producing a nitrogen-potassium sulfate fertiliser and hydrochloric acid comprises converting fine potassium chloride and/or cyclone dust of potassium chloride of concentrated sulfuric acid at an elevated temperature to obtain a solution containing potassium hydrogen sulfate, hydrochloric acid, excess of sulfuric acid; separation of hydrochloric acid vapours from solution, condensation of vapors to produce hydrochloric acid, neutralisation of potassium hydrogen sulfate with ammonia, crystallization and separation of precipitate crystals from solution. The fine potassium chloride and/or the cyclonic dust of potassium chloride are dissolved in water before the conversion step, the resulting solution is converted with concentrated sulfuric acid at a ratio H₂O/KCl=1.5-2.5, keeping the concentration of sulfuric acid 35-46% in the reaction medium, separating the hydrochloric acid vapours from the solution under the boiling point of the solution and condensing, the resulting solution is cooled with crystallization of potassium hydrogen sulfate, which is separated from solution and neutralized with ammonia water by washing the precipitate in the filtration step, and the resulting filtrate is returned to the conversion step.

EFFECT: invention allows to increase the rate of conversion, to exclude the formation of a by-product - ammonium sulfate.

2 cl, 4 dwg, 4 tbl, 2 ex