REVERBERATORY SMELTING OF COPPER CONCENTRATES

1,130,255. Reverberatory furnaces. CONZINC RIOTINTO OF AUSTRALIA Ltd. 15 Nov., 1966 [22 Nov., 1965], No. 51145/66. Heading F4B. [Also in Division C7] A reverberatory furnace comprises converting- smelting and slag separation zones B, A, C respectively-metal and slag tapholes 26 at opposite ends with conveyers 31 for introducing the metal concentrate into the smelting zone A so as to form a restricted zone 35 in said zone A, and oxygen lances 36 and 41 projecting through the side walls or roof of the furnace, the tips of said lances being located beneath the surface of the slag layer to cause turbulence. The furnace hearth 19, 18, 20 generally slopes from the slag taphole end to the metal taphole end, so that smelted metal concentrate slowly flows downwards from the hoops 34 in zone A to zone B and finally to the sump 21, while the slag, due to the turbulence of the lances, is forced from zone B through the restricted space into zone C, where it is mixed with suitable reductants 48 which assist in the removal of the metal to the bottom of the slag pool 25. Burners 37 play on the banks of concentrate 34, side burners 50 induce circulation of slag, end burners 52 play on the slag pool 25 and end burners 55 play over a copper reservoir 22. In a modification, Figs. 3 and 4 (not shown), lances are disposed in the side walls and with two charging conveyers on one side the heaps of charge material form a narrow sinuous passage for the slag. Another modification, Fig. 5 (not shown), has two gas offtakes above the ends of the charging conveyers. In another modification, Fig. 6 (not shown), the conveyers feed on to rotary drums and in a final modification, Fig. 7 (not shown), the conveyers drop the charge through roof openings. The furnace may also be L- or U- shaped.