| 摘要 |
FIELD: mineral fertilizers. SUBSTANCE: fertilizer contains, wt %: ammonium nitrate 75 +/- 7, ammonium dihydrophosphate 3 +/- 1, calcium hydrophosphate 8 +/- 3, calcium sulfate 14 +/- 4, nitrogen 24-29m and phosphorus pentoxide 4-8. Fertilizer is prepared by decomposing apatite concentrate with nitric and sulfuric acid followed by neutralizing pulp with ammonia, granulation and drying of product using drying agent with initial and end temperatures 180 C and 70-80 C, respectively. Neutralization is carried out by adding ammonium nitrate solution with concentration at least 70% and in amount 420 to 690 kg per 1 t desired product. Decomposition of apatite concentrate proceeds in two steps. EFFECT: enabled production of mixed nitrogen- phosphorus fertilizer with reduced risk of fire, increased statistical strength of granules (5 kg/granule), and by 30% reduced conglomeration on storage. 4 cl |
