(中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 為了高效回收含鐵酸鋅物料中的有價金屬，本研究通過硫化焙燒將鐵酸鋅選擇性地轉(zhuǎn)化為硫化鋅和鐵氧化物或單質(zhì)鐵，再通過常規(guī)選礦和濕法冶金的方法實現(xiàn)鐵鋅分離與回收。利用HSC和Factsage軟件研究鐵酸鋅硫化反應(yīng)熱力學(xué)，通過硫化焙燒試驗研究了不同工藝條件對鐵酸鋅硫化行為和物相轉(zhuǎn)變機制的影響。結(jié)果表明：在高溫條件下，黃鐵礦分解產(chǎn)生的氣體硫和鐵酸鋅發(fā)生硫化反應(yīng)，溫度、黃鐵礦和碳用量均為鐵酸鋅硫化的主要影響因素，適當(dāng)提高溫度及增加黃鐵礦和碳用量可以提高鋅的硫化率，添加適量鈉鹽有助于鐵酸鋅硫化。在最佳工藝條件下，鐵酸鋅硫化率可達(dá)84%。經(jīng)XRD和SEM分析，硫化焙燒主要產(chǎn)物為硫化鋅和鐵氧化物，人造硫化礦的晶粒較小，添加鈉鹽能夠促進(jìn)人造硫化鋅晶粒的長大。
關(guān)鍵字: 鐵酸鋅；選擇性硫化；還原焙燒；物相轉(zhuǎn)變；資源回收
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:In order to recover valuable metals from zinc ferrites, a sulfidation roasting was developed to selectively convert zinc ferrite into zinc sulfides and iron oxides or metallic iron, after which the separation and recovery of zinc and iron can be achieved by mineral processing and hydrometallurgical process. The thermodynamics of the sulfidation reactions of zinc ferrite was studied by HSC and Factsage calculations, and the effects of different process conditions on the sulfidation behaviors and phase transformations of zinc ferrite were investigated by sulfidation roasting experiments. The results show that the gas sulfur produced by pyrite decomposition reacts with zinc ferrite at high temperatures. The temperature, pyrite dosage and carbon dosage are the main influencing factors for the sulfidation behaviors of zinc ferrite. Appropriately increasing the temperature, the pyrite dosage and carbon dosage, the zinc sulfidation rate can be improved. Adding an appropriate amount of sodium salt is helpful to zinc ferrite sulfidation. Under the optimum conditions, the sulfidation rate of zinc ferrite can reach 84%. The XRD and SEM analysis results indicate that the roasting product is mainly composed of zinc sulfides and iron oxides, which are mainly in the form of fine grains. The addition of sodium salt can promote the grain growth of synthetic zinc sulfides.
Key words: zinc ferrite; selective sulfidation; reduction roasting; phase transformation; resource recovery
