METHOD OF WATER-RESISTANT AMMONIUM SALTPETER PREPARATION Russian patent published in 2009 - IPC C01C1/18 

FIELD: chemistry.

SUBSTANCE: invention refers to chemical industry and can be used in the manufacture of the slow-release mineral fertilisers and water-resistant explosives on the base of ammonium saltpetre. The method of water-resistant ammonium saltpeter preparation consists in treatment of ammonium saltpeter with water repellent. The gel-like mixtures of mineral acids or its salts with liquid glass with mass ratio acid or salt to liquid glass equal 1:5-40 are used as water repellent. The treatment is carried out at mechanical stirring of the ammonium saltpeter and water repellent with its mass ratio equal 1 : 0.05 - 0.1 during the time enough for full granula coating but not less than 10 min with following dehumidification preferably not less than during 20 min at the temperature providing the stability of the gel, preferably not lower than 20°C.

EFFECT: method provides the significant increasing of the ammonium saltpetre water resistance as well as the decreasing of its solubility and caking ability.

3 cl, 1 tbl, 3 ex