(1. 北京科技大學(xué) 土木與資源工程學(xué)院, 北京 100083；
2. 金屬礦山高效開采與安全教育部重點(diǎn)實(shí)驗(yàn)室, 北京 100083)
摘 要: 采用“磁化焙燒-硫脲浸金-磁選-堿浸除雜”的金鐵梯級提取法從焙燒氰化尾渣中浸出金，并制取鐵精粉，通過物相轉(zhuǎn)化、焙燒過程熱力學(xué)計(jì)算和顆粒群結(jié)構(gòu)分析，揭示鐵精粉中雜質(zhì)形成機(jī)理。結(jié)果表明：氰化尾渣添加8%焦粉于700 ℃下磁化焙燒60 min，焙燒樣以硫脲法浸金，金浸出率達(dá)65.87%；浸金渣經(jīng)磨礦磁選得到TFe品位為55.01%的初級鐵精粉，再于90 ℃的10%NaOH溶液中堿浸8 h，可得TFe品位為62.22%、回收率為69.80%的合格鐵精粉。物相轉(zhuǎn)化和熱力學(xué)計(jì)算表明，磁化焙燒過程中含鐵礦物與Si、Ca、Al及重金屬等雜質(zhì)反應(yīng)，生成鐵橄欖石、鈣鋁榴石和鐵鈣輝石等新物相，與磁鐵礦緊密共生，混入鐵精粉中；微細(xì)粒磁鐵礦存在嚴(yán)重磁團(tuán)聚，石英等雜質(zhì)會機(jī)械夾雜在磁團(tuán)聚中，降低鐵精粉質(zhì)量。
關(guān)鍵字: 焙燒氰化尾渣；梯級提取；磁化焙燒；鐵精粉；堿浸；物相轉(zhuǎn)化；熱力學(xué)計(jì)算
（1. School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, Ministry of Education, Beijing 100083, China）
Abstract:A cascading process, namely, magnetization roasting-thiourea leaching-magnetic separation-alkaline leaching, was developed to extract gold and prepare iron concentrates (ICs) from roasting cyanide tailing (RCT). The formation mechanisms of impurities in ICs were revealed by phase transformation, thermodynamics calculation and structure analysis. The results show that, after magnetization roasting of RCT by adding 8% coke powders at 700 ℃ for 60 min, Au extraction rate of 65.87% is achieved by thiourea leaching. Rough ICs with TFe grade of 55.01% are obtained by grinding and magnetic separation of leaching residue. By further leached in 10% NaOH solution, qualified ICs with TFe grade of 62.22% and recovery of 69.80% are prepared. The phase transformation and thermodynamics calculation reveal that fayalite, grossular and hedenbergite, tightly combing with magnetite, are generated by reacting iron oxides with Si, Al, Ca and heavy metals. Structural analysis exhibits that the impurity minerals are mechanically mixed into formed magnetic agglomerates, resulting in low quality of ICs.
Key words: roasting cyanide tailing; cascading recovery; magnetization roasting; iron concentrates; alkaline leaching; phase transformation; thermodynamics calculations
