ABSTRACT

Gold-bearing dust generated during the roasting process of refractory gold concentrates is valuable as secondary gold resources. In this study, the characterization of gold-bearing dust from carbon-bearing gold concentrates was determined by direct cyanidation and mineralogy research. Moreover, identification of refractoriness in the dust was determined by selective removal of minerals. Results showed that the dust belonged to refractory ores. Gold was observed to be presented as native and electrum which main associated with iron oxides. After preleaching with a 6 mol/L NaOH solution, arsenic, and carbon removal rates were 99.66% and 60.63%, respectively, and gold extraction was 58.90%, only 4.60% higher than that of direct cyanidation. After preleaching with a 15 wt.% H₂SO₄ solution, iron, arsenic, and carbon removal rates were 33.65%, 80.38%, and 12.60%, respectively, and gold extraction achieved 80.40%. After roasting, carbon and arsenic removal rates were 95.00% and 54.65%, respectively, and gold extraction achieved 84.52% under the optimum condition. Removal of carbonaceous matter and iron oxides could efficiently improve gold extraction, and the adverse effects of carbonaceous matter and iron oxides were the main reasons for refractoriness. Based on these results, a proper process for gold extraction from the dust was developed, and gold extraction achieved 95.50%.

摘要

难熔金精矿在焙烧过程中产生的含金粉尘作为次生金资源是有价值的。在这项研究中，通过直接氰化和矿物学研究确定了含碳金精矿中含金粉尘的特征。此外，通过选择性去除矿物质来确定粉尘中的耐火度。结果表明，粉尘属于难选矿石。观察到金以天然和金银形式呈现，主要与氧化铁有关。经6 mol/L NaOH溶液预浸后，砷、碳去除率分别为99.66%和60.63%，金提取率为58.90%，仅比直接氰化法提高4.60%。用 15 wt.% H ₂ SO _4预浸后溶液、铁、砷和碳的去除率分别为33.65%、80.38%和12.60%，金提取率达到80.40%。焙烧后碳、砷的去除率分别为95.00%和54.65%，最佳条件下金的提取率达到84.52%。去除含碳物质和氧化铁可以有效提高金的提取率，而含碳物质和氧化铁的不利影响是耐火度的主要原因。在此基础上，制定了合适的粉尘提金工艺，提金率达到95.50%。