METHOD OF ULTRAMARINE PRODUCING Russian patent published in 1997 - IPC

FIELD: paint and varnish industry. SUBSTANCE: mixture consisting of kaolin, 41-47% perlite of its total amount in charge and sodium hydroxide an aqueous solution at concentration 200-400 g/l at ratio solid : liquid = (2.7-3): 1 is subjected for thermic treatment at 450-550 C for 1-1.5 h. Then mixture is stirred with other amount of perlite and the following charge components: sulfur, soda, reducing agent - coal pitch and sodium formate and charge is calcined for two stages - at 600-650 C and 250-600 C, respectively. Pigment yield is 73-74%, staining capability - 235-245%, decrease of sulfur loss is 3-4%, decrease of energy consumption is 6-10%. EFFECT: improved method of producing. 4 cl, 3 tbl