文摘
The direct oxidation of stibnite (Sb2S3) using a gas mixture of nitrogen-oxygen was investigated in a pilot plant. Steady-state pilot operation of 5 and 10?t/d was normally observed during the pilot test of 100 days, and a cleaning experiment of high-antimony molten slag from oxygen-enriched bottom-blown was tested by direct reduction in a laboratory-scale electric furnace. Autogenous smelting was achieved without adding any other fuel, which guaranteed the feasibility and advantage of oxygen-enriched bottom-blown stibnite. Through analysis and calculation, the sulfur dioxide concentration in offgas was more than 8?pct, which meets the requirement for the preparation of sulfuric acid. In the reduction experiment, the effects of added CaO, the ratio of coal (ω?=?actual weight of coal/theoretical weight of coal), and the slag type on the reduction procedure were considered. The residual slag obtained after reduction averaged less than 1?g/ton Au and less than 1?wt pct Sb. The metal phase contained iron less than 3?wt pct, and the recoveries of Au in the metal phase were more than 98?pct. This process shows significant environmental and economic benefits compared with previous processes.