碘化法提取废旧手机线路板微生物浸出残渣中的金

摘要

The iodine⁃iodide leaching system was adopted to extract gold from the residue after bioleaching PCB of waste mobile phone. Effects of various factors, such as the mass fraction of iodine, the mole ratio of iodide and iodine, hydrogen peroxide dosage, liquid⁃solid ratio, the pH value of solution and leaching time, on the gold extraction were investigated, with results taken for orthogonal test, leading to the following optimal gold leaching conditions. It is shown that with the initial iodine mass fraction of 1.0%, mole ratio of iodine and iodide at 1∶10, hydrogen peroxide dosage of 1.5% , solid/liquid ratio at 1∶20, pH=7, leaching process at 28 ℃ for 4 h can result in the gold leaching rate up to 95.12%. This environmentally friendly gold extraction technique consisting of bioleaching and gold extraction with iodide process, may provide technical reference and theoretical guidance for the recycling and utilization of those electronic wastes.%采用绿色化学试剂碘⁃碘化钾体系提取废旧手机线路板（ PCB）微生物浸出残渣中的金（ Au），全面考察了碘质量分数、碘与碘化钾摩尔比、双氧水用量、固液比、pH值、浸出时间等因素对碘化法提Au的影响，并通过正交试验确定了最优浸金条件。结果表明，碘化法浸Au的最佳条件为：碘质量分数1．0％、碘与碘化钾摩尔比1∶10、双氧水用量1．5％、固液比1∶20，在pH＝7、温度28℃条件下振荡反应4 h，Au浸出率达到95．12％。微生物预处理⁃碘化法提金工艺绿色环保，有望为电子废弃物资源化领域提供一定的技术参考和理论指导。