(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(shí)，氯化浸出液中98%以上的Au將被還原沉淀至粗金粉中，同時(shí)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(duì)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(shí)，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(duì)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(jiàn)，通過(guò)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
