METHOD FOR PRODUCTION OF FERRUM-CONTAINING PIGMENT Russian patent published in 1997 - IPC

FIELD: technology of production of inorganic pigments which may be used by production of inorganic ferrum-containing modified pigment. SUBSTANCE: method involves production of working solution of ferrum-containing raw materials followed by its dehydration, modification, drying and dispersing. Ferrum-containing concentrate being prepared at metallurgical plants during thermal processing of waste etching sulfate and(or) hydrochloride solutions is used as ferrum-containing raw materials. Then repulping with water is carried out till concentration of ferrum-containing concentrate is 300-350 cu. dm. Salts of bivalent ferrum are oxidized to three-valent condition is carried out, the process takes place with the help of Bertholet's salt in acid medium at pH 2.5-4. The neutralization with powder technical belite to pH 5.5-6.0 is carried out. After filtration paste is modified by melamine-formaldehyde resin, its quantity being 2-6 % of mass of pigment. EFFECT: increased dispersity of pigment, decreased expense of pigment; decreased amount of sewage by production. 1 tbl