某高砷高硫金精矿焙砂浸金特性的研究

某高砷高硫金精矿焙砂含Au 84.27 g/t, 含As 0.55%、S 1.03%, 生产现场金的氰化浸出率不足80%, 迫切需要查明该焙砂的浸金特性。结合化学成分和物相分析, 发现含铁物相包裹是浸金渣中残留金难以浸出的根本原因。浸金渣残留金(19.54 g/t)中包裹金占96.66%, 主要包裹物相有氧化铁、毒砂和黄铁矿等含铁物相, 92.68%的包裹金存在于这些含铁物相中。浸金试验中焙砂及浸金渣所达到的浸出率分别只有84.47%、16.70%, 进一步验证了含铁物相中的包裹金极难浸出, 焙砂的浸金率很难继续提高。

Study on Characteristics of Leaching Gold from A Calcine of High-Arsenic and High-Sulfur Gold Concentrate

A calcine of high-arsenic and high-sulphur gold concentrate assayed 84.27 g/t Au, 0.55% As, 1.03% S was in-situ treated with cyanide leaching process, resulting in a gold leaching rate just less than 80%, indicating an urgent need for exploring characteristics of gold leaching from such calcine. Based on the chemical compositions and phases analysis, it is found that the primary cause for the difficult leaching of gold from such leach residue is that the gold being trapped inside some ferrous phase. Tests show that the inclusion gold accounts for 96.66% in the leach residue assaying 19.54 g/t Au, predominately enclosed within ferrous phase(around 92.68%), such as iron oxide, arsenopyrite and pyrite. In the tests, the gold-leaching rates from calcine and gold-leach residue were just 84.47% and 16.7%, respectively, further verifying the difficulty in the leaching of the inclusion gold in ferrous phase, thus the gold-leaching rate from calcine is hardly improved.