METHOD OF PROCESSING PRODUCTS OF SULFITE LYE BIOCHEMICAL OXIDATION Russian patent published in 1998 - IPC

FIELD: lignin chemistry. SUBSTANCE: invention relates to processing sulfite lyes and other products containing lignosulfonates and other lignin derivatives and may be used for preparing materials containing anionic biodegradable surfactants. Such materials can be used, for example, either as components of drilling fluids or as components of compositions used for granulation of organomineral fertilizers. Product of biochemical oxidation of sulfite lyes is heated to 40-120 C, alkali agent is added to pH 6-9, and ozonation of mixture obtained is conducted with ozone concentration in ozone-air mixture from 1.0 to 10.0 mg/cu.dm. Then, additional alkali agent in amount 30-40% based on weight of organic substances is added, mixture is heated to 170-190 C, and air under pressure 2.5-3.0 MPa is bubbled with specific uptake 50-65 h^-1 for 0.5-2.0 h whilst maintaining pH 6.0-9.0. Mixture is finally cooled and repeatedly ozonized to summary dose of ozone 1-2% based on weight of organic substances. EFFECT: improved surfactant characteristics of product and increased degree of biochemical decomposition of processing products. 1 tbl