METHOD OF PURIFYING POTASSIUM NITRATE Russian patent published in 2013 - IPC C01D9/16 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of purifying potassium nitrate to obtain a highly pure product which can be used in modern science and engineering fields (fibre optics, optical glass manufacturing, monocrystallites etc). Aqueous potassium nitrate solution is purified by treating, while stirring, a starting aluminium nitrate product taken in an amount of 1.5-2.5% of the mass of potassium nitrate, and diluted aqueous potassium hydroxide solution to pH 7.5-8.2, followed by filtering the precipitate, evaporating the purified potassium nitrate solution to density of not more than 1.3-5 g/cm³, cooling to 20-25°C, separating the precipitated crystallites, preferably by centrifuging at 500-2000 rpm and drying at 100-110°C.

EFFECT: obtaining potassium nitrate with higher purity.

4 cl, 3 ex