GB792846A - Continuous method for reducing oxidic zinc ores indirectly by means of carbon and apparatus for carrying out the method - Google Patents

Abstract

792,846. Extracting zinc. WARLAND, E. July 18, 1955 [July 26, 1954], No. 20678/55. Class 82(1) [Also in Group XII] In a continuous process and an apparatus for reducing acidic zinc ores indirectly by means of carbon and in which the reduction of the zinc oxide is effected with an intermediate reducing agent in a bath of molten slag resulting from previous reduction of such ore, the pulverized ore with fluxes if desired is admitted through tuyeres 10 into the slag bath in the reducing compartment 2 which is in communication via passages 4, 5, with the regenerating compartment 3 to which powdered coal or coke is admitted by tuyeres 11 for the regeneration of the intermediate reducing agent (ferro-silicon iron, silicon, magnesium-iron) initially added to the slag. Zinc vapour is led from shaft outlet 8 to a condenser; slag is periodically tapped at 12, 13; heavy molten metals from the ore, e.g. copper, lead, may be run off as desired at 16, 17; combustion air preheated or enriched with oxygen, or oxygen itself, together with steam if desired are introduced by the tuyeres 10, 11. The ferro-silicon &c. reacts with the zinc ore in chamber 2 to liberate zinc vapour, the oxidized silicon and iron rising through passages 4 into the slag bath 3 where these oxides are regenerated by the coal or into (molten) ferro-silicon which sinks by gravity to pass back through passages 5 into the chamber 2, the cycle being continuous. The gaseous products, mainly CO and nitrogen, leaving at 9 may be burned and used to preheat the combustion gases.