GB268301A - Improvements in or relating to the manufacture of zinc oxide - Google Patents

Abstract

268,301. New Jersey Zinc Co., (Assignees of Singmaster, J. A., Breyer, F. G., and Bunce, E. H.). March 27, 1926, [Convention date]. Zinc oxide.-Zinciferous and carbonaceous materials are heated to reduce the zinc compounds and volatilize the metallic zinc which is next oxidized, the resulting gases with zinc oxide in suspension being then conveyed to a zinc oxide collecting means and meanwhile maintained at not less than about 125‹ C. until the gases are separated. Fuel briquets such as coal are fed at 11 on to a perforated travelling grate 13 and fuelore briquets are fed into a chute 16 in a chamber 17 heated by gases in pipes 18, 19, 20 from a fuel ignition chamber 14, the level of the briquets being adjusted by members 12, 21. Air is passed up through the grid 13 and regulated so that substantially non-oxidizing conditions are maintained above the briquets. The zinc vapour and burnt gases pass up through outlets 23 into nozzles of gas compartments 24 where the zinc is oxidized and immediately cooled bv a regulated a.ir blast 26 to preferably 500‹ but not above 700‹ C., the oxide being drawn by a fan 30 through the hood 28 and pipes 29, 32, 33 into asbestos filter bags 35 and hoppers 36. Beyond the main chamber 22 is a chamber 39 where it is difficult to maintain a non-oxidizing layer above the charge, and whence the gaseous products are drawn through a pipe 41. The pipe 43 communicates with the air. The zinc oxide is thus substantially freed from sulphur compounds. Other forms of furnace may be used, and the ore need not be briquetted. Specifications 149,927 and 219,423 are referred to.