Apparatus for suspension smelting of finely-grained oxide and/or sulfide ores and concentrates

In an improved suspension smelting furnace for the suspension smelting of finely-grained oxide or sulfide ores and concentrates, and of the type having

• (1) as a base a horizontal lower furnace comprising a main smelt reaction zone and a settling zone;
• (2) at least one vertical suspension reaction zone communicating at its lower end with the horizontal lower furnace;
• (3) at least one vertical rising-flow zone communicating at its lower end with the horizontal lower furnace;
• (4) means attached to the upper end of the suspension reaction zone for the production of a suspension of finely-grained oxide and/or sulfide ores or concentrates with air, oxygen or both, and for feeding this suspension downwards in the reaction zone;
• wherein said main smelt reaction zone in the lower furnace is under the suspension reaction zone and in which main smelt reaction zone the bulk of the suspension is adapted to be dissolved vertically in the smelt accumulated in the lower furnace main smelt reaction zone;
• (5) and means attached to the upper end of the rising-flow zone for withdrawing the residual suspension, the improvement comprising;
• said horizontal lower furnace which includes 3 zones (a), (b) and (c) wherein
• (a) is the main smelt reaction zone disposed under said suspension reaction zone;
• (b) is a secondary smelt reaction zone in the lower furnace which is disposed under said rising-flow zone, wherein the residual suspension is allowed to at least partially dissolve in the smelt before essentially all undissolved residual suspension is fed into the rising-flow zone;
• (c) is the smelt settling zone in the horizontal lower furnace communicating at least through the smelt with the main and secondary smelt reaction zones for the separation of slag from matte and metal, and comprising means for withdrawing slag, metal, and matte from the horizontal lower furnace, in which the main smelt reaction zone is placed in close proximity to the rising-flow zone in order to minimize the area of the secondary smelt reaction zone so that the retention time of the residual suspension in the horizontal lower furnace is minimized;
• and
• (d) two vertical shafts, each of which is connected at its lower end with the horizontal lower furnace, (i) one of said two vertical shafts encompassing the reaction zone of (2) and (ii) the other of said two vertical shafts encompassing the rising-flow zone of (3), wherein (ii) is disposed concentrically about (i) in an arrangement wherein a cross-section of the arrangement is ring-shaped.