METHOD FOR PREPARING HUMINIC ACID SALTS Russian patent published in 2003 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to preparing huminic acids salts and can be used in preparing fertilizers, as component of drilling fluid, as dye of wood, corrosion inhibitor and scale. Method involves high-temperature treatment of an aqueous suspension of vegetable raw in continuous regime for two steps in the presence of air as oxidative agent with specific consumption 20-65 nm³/m³h.. At the first step preoxidation is carried out in circulatory contour at 50-190 C under pressure 0.5-3 MPa up to value pH = 10.5- 12. At the second step the main oxidation is carried out at stirring by circulatory pump with simultaneous activation of raw mixture and alkaline agent at 170-210 C, under pressure 0.5-3 MPa up to value pH = 8.5-10, followed by mixing with sodium hydroxide as alkaline agent, oxidation and cooling. At the second step of thermal treatment or after cooling the ready product to 70-100 C dry salts containing trace elements of the composition: and boric acid are added additionally. Lignosulfonate as by-side product of preparing cellulose by sulfite method and lignin as by-side product of hydrolysis manufacture are used as vegetable raw. Method allows to provide preparing product in continuous regime. EFFECT: improved preparing method, increased yield. 1 tbl