某锑金矿综合回收锑、金的试验研究

采用酸法浸锑-浸锑渣焙烧脱硫-氰化浸金工艺从某锑金精矿中分离提取锑、金。酸法浸锑最佳工艺条件为: 温度为95 ℃、H⁺]=4 mol/L、液固比为4∶1、FeCl₃过量系数为1.1、浸出时间为0.5 h, 在此条件下, 锑浸出率为99.05%, 进入浸锑液的金仅为0.99%, 实现了锑、金良好的选择性浸出。对浸锑渣直接氰化浸金, 浸金率仅为71.93%。为了提高浸金率, 在分析酸性浸锑渣的矿物组成的基础上, 对浸锑渣进行氧化焙烧, 结果表明: 碚砂中硫品位仅为0.18%, 硫脱除率达到了99.81%, 渣中的单质硫及硫化物显著减少, 主要以赤铁矿和脉石矿物为主。最终金浸出率达到95.92%, 比浸锑渣直接氰化浸金提高了约24个百分点。

Comprehensive Recovery of Au and Sb from an Antimony-gold Concentrate

Comprehensive recovery of Sb and Au from an antimony-gold concentrate is studied by adopting a process of Sb leaching with acid solution-oxidizing roasting of the antimony residue-cyanide leaching of gold. Under the following optimum conditions, that is, leaching at 95 ℃ for 0.5 h with HCl concentration at 4.0 mol/L, liquid-solid rate at 4∶1, excess coefficient of FeCl₃ being 1.1, a favorable selective leaching effect can be realized for Sb and Au, with the leaching rate of Sb up to 99.05% and only 0.99% Au recovered into antimony leachate. However, the following direct cyanide leaching only resulted in the Au leaching rate of 71.93%. For the purpose of increasing the leaching rate of Au, the antimony leaching residue was subjected to oxidizing roasting process based on the analysis of its mineral compositions, leading to only 0.18% S in the calcined product, with removal rate of sulfur up to 99.81%. It is found that hematite and gangue minerals are the dominant minerals in the residue, with the content of sulfur and sulfide remarkably decreased. The ultimate leaching rate of Au reached 95.92%, 24 percentage points higher than that by direct cyanide leaching process.