(1. 江西銅業(yè)集團(tuán)公司 江西銅業(yè)技術(shù)研究院有限公司，南昌 330096；
2. 江西銅業(yè)集團(tuán)公司 貴溪冶煉廠，貴溪 335424)
摘 要: 以亞硫酸鈉為還原劑，研究采用控制電位還原法回收氯化浸出液中的貴金屬。結(jié)果表明：當(dāng)控制金還原電位為530~550 mV時，氯化浸出液中98%以上的Au將被還原沉淀至粗金粉中，同時Pt、Pd和Te基本不被還原沉淀，所得粗金粉中Au含量在98%以上，Se、Te、Cu和Pb等雜質(zhì)的含量均低于0.10%(質(zhì)量分?jǐn)?shù))，而且該金還原電位對不同Au濃度或酸度的氯化浸出液都具有良好的適應(yīng)性；然后當(dāng)控制鉑鈀還原電位為390~420 mV時，金還原后液中的Au、Pt和Pd將被還原沉淀至1 mg/L以下，而Te基本不被還原，所得鉑鈀精礦中貴金屬含量高、雜質(zhì)含量少，且所確定的鉑鈀還原電位對不同鉑鈀濃度或酸度的金還原后液以及反應(yīng)溫度均具備較好的適應(yīng)性。可見，通過控制電位還原，可將氯化浸出液中貴金屬選擇性沉淀并與其他元素初步分離。
關(guān)鍵字: 氯化浸出液；貴金屬；電位；還原；亞硫酸鈉
（1. Jiangxi Copper Technology Research Institute Co., Ltd., Jiangxi Copper Corporation, Nanchang 330096, China;
2. Guixi Smelt, Jiangxi Copper Corporation, Guixi 335424, China）
Abstract:Using sodium sulfite as the reducing agent, the recovery of noble metals in chlorination-leaching solution by potential-controlled reduction was investigated. The results show that, when the reduction potential of Au is controlled at 530-550 mV, 98% Au in the chlorination-leaching solution is reduced and precipitated as raw-gold powder while Pt, Pd and Te are almost not reduced. The content of Au in the obtained raw-gold powder is above 98% and those of Se, Te, Cu and Pb are all lower than 0.10% (mass fraction). Also, the potential value of gold reduction has good adaptability to many different kinds of the chlorination-leaching solutions that have various concentrations of Au or H+. Then, when the reduction potential of Pt/Pd is controlled in 390-420 mV, the concentration of Au, Pt and Pd in the precipitated-gold solution can be reduced to below 1 mg/L while most of Te still remains. The content of noble metals in the collected Pt-Pd concentrate is remarkably high and that of impurities is comparatively low. In addition, the determined potential value of Pt/Pd reduction exhibits greatly adaptable to those precipitated-gold solutions with different Pt/Pd concentrations or acidity as well as reaction temperature. Accordingly, the noble metals in chlorination-leaching solutions will selectively precipitate and preliminarily separate from other elements by potential-controlled reduction method.
Key words: chlorination-leaching solution; noble metal; potential; reduction; sodium sulfite
