RAW MATERIAL FOR SILICATE PHOSPHATE FERTILIZER AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a raw material for silicate phosphate fertilizer having excellent solubility of silicate and small alkali content, containing an adequate quantity of phosphate to become an effective component of fertilizer and manufactured at a low cost. SOLUTION: Slag recovered in a molten iron previous treatment process of blast furnace molten iron and having a specific basicity is utilized as the raw material of the silicate phosphate fertilizer as it is without applying a specific treatment and has excellent characteristics as fertilizer. The slag contains silicate which is an oxide of silicon in the molten iron and phosphate which is an oxide of phosphorus in the molten iron and has basicity (CaO/SiO2) of≥1.0 to <1.5 and contains 10 mass% soluble silica. The slag contains 2 mass% soluble phosphate and the mass ratio [(C-P2O5)/(S-SiO2)] of the soluble phosphate (C-P2O5) to the soluble silicate (S-SiO2) in the slag is regulated to 0.1-0.8. COPYRIGHT: (C)2005,JPO&NCIPI