某难处理金矿热压氧化渣预处理试验研究

高铜难处理金矿经酸性热压氧化后，铜基本被浸出进入溶液中，消除了铜对氰化过程的影响，而银在热压处理过程中易与生成的黄钾铁矾相结合，生成难处理的银铁矾AgFe₃（SO₄）₂（OH）₆]，在随后的常规氰化试验中，金回收率达99%以上，但银回收率不足10%。针对银回收率低的问题，系统考察了矿浆浓度、NaCN浓度、石灰用量、预处理温度和时间、氰化时间及炭密度等因素对金、银浸出率的影响，进而确定了最佳浸出条件。试验结果表明：在85~90 ℃、矿浆浓度为40%、石灰用量为40 kg/t的条件下，对氧化渣进行碱性预处理，随后在NaCN用量为0.10%的条件下浸出8 h，银回收率得到大幅提高（达到85%），金浸出率也保持在99%以上。

Recovery of Gold and Silver from Pressure Oxidative Slag of Refractory Gold Ore

After acidic pressure oxidation of refractory gold ore containing copper,copper were basically leached into the solution and eliminated the influence on cyanide process,while silver in the pressure oxidation process could combine with jarosite to generate AgFe3(SO4)2(OH)6].The gold and silver recovery rate reached respectively over 99% and less than 10% in conventional cyanide process.This paper investigated the effect of pulp density, dosage of sodium cyanide and lime,pretreatment temperature and time,cyanide time and carbon density to leaching rate for gold and silver,finally the optimum leaching condition was determined.The silver recovery was improved substantially after silver pretreatment on the condition of 85~90 ℃,pulp concentration of 40% and lime dosage of 40 kg/t which achieved about 85%,meanwhile,the gold leaching rate also remain above 99%.