某难处理金精矿热压预氧化-氰化浸金实验

对某难处理金精矿进行了热压预氧化-氰化浸金实验,探讨热压预氧化温度、时间、氧化分压和矿浆浓度对金浸出率和氰化钠耗量的影响。结果表明,在粒度-44μm占90.74%、温度220℃、矿浆浓度25%、氧分压0.8 MPa和转速750 r/min条件下预氧化2.5 h,砷主要以稳定的结晶状砷酸铁或者臭葱石形式被固定在氧化渣中;预氧化渣在矿浆浓度33%、pH=10~11、初始氰化钠浓度0.3%和活性炭浓度25 g/L条件下氰化浸出24 h,与金精矿直接氰化相比,浸出率由11.21%提高至95.75%,氰化钠耗量从46.99 kg/t降低至1.36 kg/t。

Study on Extracting Gold from a Refractory Gold Concentrate by Hot Pressing Preoxidation and Cyanidation Leaching

A process involvinghot pressing preoxidation and cyanidation leaching has been studied to extract gold from a refractory gold concentrate. The effects of temperature, time, partial pressure of oxidation and concentration of pulp on gold leaching rate and consumption of sodium cyanide were investigated. The results showed that arsenic would mainly be fixed in the oxidized slag in the form of stable crystalline arsenate iron or scorodit, after the refractory gold concentrate with a particle size of -44 μm accounting for 90.74％ and at a pulp concentration of 25％ was preoxidized at 220℃ for 2 hours. Then the preoxidized salg was leached for 24 hours at a pH value of 10～11 by using 0.3％ sodium cyanide under the condition of 33％ pulp concentration and 25 g/L activated carbon concentration. The leaching rate of gold was increased to 95.75％ from 11.21％ obtained by direct cyanidation of gold concentrate without the preoxidation and the consumption of cyanide was reduced to 1.36 kg/t ore from 46.99 kg/t ore .