METHOD FOR PREPARING NITROGEN-PHOSPHORUS FERTILIZER Russian patent published in 2005 - IPC

FIELD: agriculture, fertilizers.

SUBSTANCE: invention relates to manufacturing nitrogen-phosphorus mineral fertilizers. Method involves ammoniation reaction of wet-process phosphoric acid with the concentration 52-57 wt.-% as measured for phosphorus pentoxide and with the content of magnesium phosphates in the amount 0.6-1.9 wt.-% as measure for MgO up to preparing diammonium phosphate solution with pH value 6.6-8.0. The solution is cleared by settling up to the mass part of magnesium phosphates 0.06-0.4 wt.-% as measured for MgO and neutralized with nitric acid up to pH value 3.8-4.6 and prepared solution of monoammonium phosphate and ammonium nitrate is mixed with ammonium nitrate melt. The prepared nitrate-phosphate solution is boiled down, additional neutralization with ammonium is carried out, granulated by prilling method and treated with an anti-caking agent. Invention provides enhancing output and diminishing losses of ammonium nitrogen.

EFFECT: improved preparing method.

2 cl, 3 ex