METHOD FOR PRODUCING PHOSPHORIC ORGANO-MINERAL FERTILIZERS Russian patent published in 1998 - IPC

FIELD: agriculture; organic chemistry. SUBSTANCE: phosphate flour or simple superphosphate are mixed with humic substances taken in amount 2-9 wt. -%, followed by drying mixture at 85-105 C. As humic substances, method employs product resulting from oxidative-hydrolytic decomposition of lignosulphonates. The latter are oxidized with air oxygen in alkaline medium, at 150-200 C and under pressure not more 2.5 MPa. Liquid phase is concentrated until its moisture content is brought down to 8-10%, followed by mixing it with mineral component. Method permits to expand range of phosphoric organo-mineral fertilizers and to improve environmental conditions due to using, as humic component, lignosulphonates constituting difficult-to-dispose wastes resulting from operation of pulp--and-paper-making plants. EFFECT: broadened range of phosphoric fertilizers for agriculture; improved environmental conditions. 4 tbl