A process for the enrichment of the iron and the iron is not difficult to metals from sulfur iron and iron oxide support strength material

摘要

PICT:0800647/III/1 Ores or concentrates containing iron sulphide are mixed with material containing iron oxide and fed through pipes 3 to a closed furnace 1 of refractory material and melted electrically by carbon electrodes 2 which project downwards through the roof of the furnace, to form a slag including silica, gangue (if any), alkaline earth (if any) and a minor portion of the iron, and a matte, which contains the major portion of the iron partly as FeS and partly as FeO, most of the copper and cobalt content (if any) and part of the zinc content. The furnace has an upper outlet 4 for the slag 8 and a lower outlet 5 for the matte 7 and, if desired, a separate outlet 6 for drawing off material from the bottom of the furnace. Reactions between the iron sulphides, iron oxides and the carbon of the electrodes 2 also produce a gaseous mixture containing zinc vapour, sulphur vapour, carbon dioxide, carbon monoxide, carbonyl sulphide and carbon disulphide. This gaseous mixture at about 500 DEG C. passes through outlet 11 and conduit 13 provided with feeding screw 14 for transporting dust which may be deposited on the wall, to electric filter 12 where zinc is removed from the gases which then pass out of the top of the filter 12 at about 400 DEG C. via pipe 15 to condenser 16 in which they are cooled down to about 130 DEG C. so that the sulphur is condensed out and removed at S. The gases pass through circulation fan 9 back to the furnace 1 through pipe 10 fitted with valve 20 which is throttled to maintain a pressure above atmospheric in the system. The resulting matte may be crushed, leached, for example with sulphuric acid, and the ferrous sulphate solution obtained electrolysed to recover the iron by the method described in Specification 650,202.