METHOD OF DRY ZINC WHITE PIGMENT PRODUCING Russian patent published in 2000 - IPC

FIELD: paint and varnish industry, inorganic pigments. SUBSTANCE: method of producing dry zinc white pigment involves thermal treatment of zinc-containing material and removal of impurities. Type-zinc as waste of hot zinc plating is used as zinc-containing material. Thermal treatment is carried out in muffles placed into furnace at 1000-1100 C and impurities are removed at regular intervals. Under optimal conditions method involves the use of type-zinc containing 90-95% of metallic zinc, 0.01-2.4% of iron, 0.01-0.1% of copper, 0.015-0.03% of lead compounds and 0.015-0.03% of cadmium compounds. Removal of impurities containing lead and iron is carried out from furnace muffle bottom. Amount of muffles into furnace is 20-28. Zinc content in dry zinc white pigment is 99.00-99.99%. EFFECT: decreased energy consumption, increased degree of zinc extraction into ready product. 5 cl, 1 tbl, 2 ex