ZINC WHITE PRODUCTION PROCESS Russian patent published in 2003 - IPC

FIELD: varnish-and-paint industry. SUBSTANCE: rotary drum furnace is heated to 800-900 C, zinc-containing raw material (hard zinc) is loaded by 5-12-kg briquettes, and temperature is raised by burning natural gas to zinc boiling temperature. Once this temperature achieved, natural gas supply into two burners is cut off and rotation of drum is started. Heating of air coming into furnace is assured by the flame of remaining burners, total gas intake being thus reduced by 50-70%. Evaporating zinc is oxidized by air oxygen heated to 600-800 C when passed into furnace. Furnace is operated under educed pressure 15-20 Pa. 2-2.5 h later, zinc white is trapped by filters, which are then regenerated. After 2-4 h operation, natural gas supply is stopped and slag discharged. Whiteness of zinc white is 95-97 conventional units, yield factor 1.0-1.05. EFFECT: simplified process and reduced expenses on raw material. 8 cl, 2 tbl