METHOD OF OBTAINING ONE-WAY PHOSPHORIC FERTILISER OUT OF LEAN RAW PHOSPHATE MATERIAL Russian patent published in 2009 - IPC C05B11/08 

FIELD: chemistry.

SUBSTANCE: invention concerns methods of obtaining one-way phosphoric fertilisers out of lean raw phosphate material. Method involves decomposition of part of raw phosphate material by sulfuric acid, neutralisation of obtained pulp by second part of raw phosphate material, and further processing of obtained pulp at high temperature. At the decomposition stage sulfuric acid of 25-35% concentration is fed in amount of 12.3-15.0 weight parts per unit of P₂O₅ of raw phosphate material. Raw material part involved at the decomposition stage comprises 48-70% of its total weight. Phosphoric acid can be fed at pulp neutralisation stage together with the rest of raw phosphate material in amount providing for ratio of P₂O₅ acid: P₂O₅ raw phosphate material=1:(0.5-1.6). Pulp obtained after neutralisation stage is processed either in granulation dryer or in rotating furnace.

EFFECT: obtaining fertilisers with required balance of nutrient elements (calcium and sulfur beside phosphor).

3 cl, 4 ex