(1. 武漢理工大學(xué) 資源與環(huán)境工程學(xué)院，武漢 430070；
2. 武漢理工大學(xué) 礦物資源加工與環(huán)境湖北省重點(diǎn)實(shí)驗(yàn)室，武漢 430070)
摘 要: 銅渣是銅火法冶煉過程中產(chǎn)生的主要固體廢棄物，碳熱還原可實(shí)現(xiàn)其主要物相鐵橄欖石的分解，有利于后續(xù)鐵的富集。本文利用XRD、SEM和EDS對銅渣碳熱還原過程中的反應(yīng)行為進(jìn)行研究，借助堿浸實(shí)驗(yàn)考察了焙燒產(chǎn)物中二氧化硅(SiO2)固溶體的溶解性，并通過XPS及TEM分析結(jié)果探討SiO2固溶體的形成機(jī)理。結(jié)果表明：銅渣中的主要物相為鐵橄欖石和磁鐵礦，鋅主要賦存于鐵橄欖石相。鐵橄欖石經(jīng)碳熱還原分解為金屬鐵和石英固溶體，溫度升高促使石英固溶體轉(zhuǎn)變?yōu)榉绞⒐倘荏w，此時(shí)鋅被揮發(fā)至煙氣中。焙燒產(chǎn)物中SiO2因鐵的摻雜而表現(xiàn)出石英和方石英的晶體結(jié)構(gòu)，但在微觀上仍以非晶態(tài)形式存在，致使其易溶于110 ℃氫氧化鈉溶液。
關(guān)鍵字: 銅渣；碳熱還原；金屬鐵；石英固溶體；方石英固溶體
（1. School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, China;
2. Hubei Key Laboratory of Mineral Resources Processing and Environment, Wuhan University of Technology, Wuhan 430070, China）
Abstract:Copper slag is the main solid waste generated during the pyrometallurgical process of copper. Fayalite as the main phase in copper slag can be decomposed into metallic iron and silica through carbothermic reduction, thereby benefiting the enrichment of iron. In this paper, the reaction behavior of copper slag during carbothermic reduction was studied through the analysis methods of XRD, SEM and EDS, meanwhile the alkali leaching experiment was introduced to test the solubility of silica in the reductively roasted copper slag, and ultimately the formation mechanism of silica solid solution was discussed combined with the analysis results of XPS and TEM. The results show that fayalite and magnetite are the predominant phases in copper slag, and zinc mainly exists in fayalite. During carbothermic reduction process, fayalite firstly decomposes into metallic iron and quartz solid solution, then quartz solid solution converts into cristobalite solid solution with increasing temperature. Meanwhile, the zinc in fayalite is removed by vaporization. Due to the doping of iron, the silica from the decomposition of fayalite by carbothermic reduction has the similar crystal structures with quartz and cristobalite, but is still in amorphous state on the micro, resulting in the violent reaction between the silica solid solution and NaOH solution at 110 ℃.
Key words: copper slag; carbothermic reduction; metallic iron; quartz solid solution; cristobalite solid solution
