GB161156A - Manufacture of zinc oxide - Google Patents

Abstract

161,156. New Jersey Zinc Co., (Assignees of Singmaster, J. A.). March 31, 1920, [Convention date]. Dry processes of refining lead.-In the production of z i n c oxide by volatilizing zinc in a retort and burning the vapour, a substantial body of molten zinc is maintained in the retort by adding zinc thereto from time to time to replace that which has been volatilized, the zinc so added being preferably molten and at a temperature near the boiling-point. The zinc may be drawn directly from a spelter furnace, but it is preferred to feed the retorts from a separate melting furnace in which a large quantity of zinc is maintained molten so that any inequalities in composition of the zinc supplied to this furnace are equalized before reaching the retorts. A reverberatory furnace 1 contains the body of molten zinc, the metal being withdrawn as required from a dip-well 2 which has a depression at the bottom as shown in which any excess of lead beyond one per cent separates and is drawn off. An overhead track 3 supported by brackets 4, 6 carries a ladle 16 which is filled from the dip-well and conveys metal to the retorts 9 which are set in chambers 7, 8. Each retort has an inlet pipe 13 for reducing gas, having a door 14 for the insertion of a funnel 15 which receives metal from the ladle 16. The pipe 13 is luted in position by clay or the like 12 when the operation is started which is broken away when it is necessary to clean out the retort. The level of metal in the retort is maintained by intermittent feeding at a considerable depth, say half full. The outlet 11 of the retort is open, and both the reducing gas and the zinc vapour burn as they issue, the zinc oxide being collected in the usual manner.