GB208716A - Improvements in or relating to the production of aluminium - Google Patents

Abstract

208,716. Aluminum Co. of America, (Assignees of Hoopes, W., Frary, F. C., and Edwards, J. D.). Dec. 21, 1922, [Convention date]. Alloys; dry processes of recovering copper; treating ores to remove undesired constituents.- A process of producing metallic aluminium comprises treating aluminium material other than chemically substantiallv to remove substances such as iron and titanium and thereafter melting other aluminous material in the presence of added material to produce aluminium alloy, and refining the alloy in a molten state to recover aluminium in metallic form therefrom. In step 1 of the process, the calcined material containing alumina with, as impurities, oxides of iron, titanium and silicon, is smelted, preferably with fluxes, in an electric furnace to obtain ferro-silicon and aluminous slag containing a little silica and iron and titanium oxides. In step 2, this slag is smelted in the presence of copper, with a reducing agent, for example, coke, to form an aluminium-coppersilicon alloy having a little iron and titanium. Silicon may be added if necessary. In step 2<a> the dross is removed leaving a clean alloy, low in iron and titanium, and in step 3 the aluminium is extracted electrolytically. In step 4, the copper is recovered for re-use in step 2, with preliminary slagging of impurities if necessary. To recover the copper for re-use, the molten residual anode alloy of the cell is poured from a vessel 51 through a furnace 52 into the path of an air-blast from a pipe 53. The solidified fragments are caught in a hopper 54 whence they are withdrawn through a shoot 55 having a sliding gate 56. Any iron and titanium remaining in the residue or alloy can be removed by slagging by the admission of air through the trunnions 57, pipe 58 and holes 59, so leaving pure copper.