METHOD OF PRODUCING GRANULAR NITROGEN SULPHATE FERTILISER Russian patent published in 2011 - IPC C05C1/00 C05D5/00 C05D9/02 

FIELD: chemistry.

SUBSTANCE: ammonium nitrate solution with concentration 90-99.5% is mixed with crushed ammonium sulphate at temperature 120-210°C. Before granulation, one of the following substances is added to the obtained suspension as an additive: boron-containing ore, ammonium sulphate, boric acid, borax, caustic magnesite, iron (III) oxide or a nitrogen-acid extract from caustic magnesite, iron (III) oxide or boron-containing ore in amount of 0.5-2.0 wt % ammonium nitrate. Granulation is carried out by rolling or by crystallising melt droplets in a tower.

EFFECT: method increases statistical strength of granules, ensures high resistance of granules to heating and cooling cycles and prevents segregation of components on the surface of granules.

3 cl, 1 tbl, 40 ex