METHOD FOR PRODUCTION OF GRANULATED COMPLEX FERTILIZER Russian patent published in 1997 - IPC

FIELD: production of complex chemical fertilizers and melioration agents. SUBSTANCE: proposed fertilizers and melioration agents are prepared on the base of industrial wastes which contain calcium sulfates. Granules are prepared by mixing of phosphorous semihydrate of calcium sulfate with aqueous solution. Said solutions comprise 60 mass % of urea and salts of microelements (their quantity being 1-5 % of mass of desired product). Humic materials are applied on said granules being preliminary dried, quantity of said humic material is 0.3-1 mass %. Then thus treated granules are additionally dried. EFFECT: improved quality of desired product. 1 tbl