METHOD OF PRODUCING DISUBSTITUTED POTASSIUM PHOSPHATE Russian patent published in 2016 - IPC C01B25/30 C01D13/00 

FIELD: technological processes.

SUBSTANCE: invention relates to production of alkali metals phosphates, particularly trihydrate disubstituted potassium phosphate. Proposed method comprises two-step neutralization of phosphoric acid by potassium hydroxide at a temperature of 60-70 °C, herewith, at the first stage neutralization is carried out with initial weight ratio of potassium hydroxide to phosphoric acid that is 0.73-0.76, obtained solution is held for 10-30 minutes, after that, at the second stage potassium hydroxide is added to phosphoric acid up to the weight ratio of potassium hydroxide, that is 0.85-1.0, filtration to separate impurities, supply of filtered solution in the reactor for producing crystalline mass, note here that supplied into the reactor solution is subjected to fast cooling up to a temperature of 35-40 °C by adding water with a temperature of not more than 20 °C, and separation of commercial product from the mother solution by centrifuging.

EFFECT: technical result consists in improvement of quality of commercial product due to content reduction of arsenic impurities and insoluble residue in it.

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