| 摘要 |
<p>In a process for the recovery of metals such as tin, lead, antimony, bismuth, &c., or alloys of these metals with or without precious metals contained in the residues obtained during the reduction of materials containing these metals in the form of oxides by the process described in Specification 367,611, any cooling of the residues withdrawn from the furnace to a temperature below the solidification temperature of the reduced metals is prevented by conserving the heat in the residues or by supplying heat to them, in order to obtain the metals in a cohering molten form and the residues are shaken to facilitate the union of the metal particles. Tappings from several furnaces may be collected in one container adapted to be shaken and preferably having heating means, a perforated false bottom, and tapholes below the bottom. Agitation may also be carried out in a rotary tube or a shaking trough or hearth. The yield of metal from the residues is increased by making up the charge into a paste with solutions of the requisite fluxes such as sodium carbonate, waterglass, &c., or by sintering the oxides to be reduced with or without additions of the fluxes before adding the reducing agent. If the sintering is carried out without or with insufficient fluxing agent a quantity of the flux may be added later to the charge in the reducing furnace. The residues remaining after the separation of the metals may be further treated by a concentration or dressing process, for example sieve-jigging or ball-milling, and the recovered metal worked up into ingots by segregation and subsequent immersion in a metallic bath. By using wood charcoal as reducing agent, the concentration of the residue may be wholly or partly obviated. The residues in these circumstances contain no graphite constituents, and after the separation of the metals with or without separating a portion of the wood charcoal remaining unconsumed, may be further worked as by smelting in a blast or reverberatory furnace, if desired after briquetting.</p> |
