Recovery of both brass and zinc from metallurgical residues by carbon flotation method

摘要

A method of recovering both brass and zinc from metallurgical residue containing those metals and including slag containing zinc oxide, comprising charging the residue into a furnace, in such furnace heating the residue up to about 1,250 DEG C., the brass which is molten at said temperature sinking to the bottom of the furnace, adding carbon reducing zinc oxide in the slag to zinc metal in vapor form, withdrawing and condensing the zinc vapor, tapping the molten slag from the furnace and tapping the molten brass from the furnace. Flux may be and normally is added to the residue to render the slag more fluid although under certain conditions addition of flux may be unnecessary. When flux is added it may comprise at least one of lime, silica, scrap glass, borax, rasorite and colemanite. The carbon reductant may comprise at least one of metallurgical coke, petroleum coke, bituminous coal, anthracite coal and graphite. The zinc vapor is withdrawn from the furnace through a first outlet passage, the slag after at least the greater portion of the zinc oxide therein has been reduced to zinc in vapor form is withdrawn from the furnace through a second outlet passage and the molten brass is withdrawn from the furnace through a third outlet passage. The furnace is preferably an electric arc furnace although a gas fired furnace or an induction furnace may be employed.