(1. 中南大學(xué) 生物冶金教育部重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
2. 中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 比較了3種典型嗜中溫鐵/硫代謝菌--Acidithiobacillus ferrooxidans、Leptospirillum ferriphilum及Acidithiobacillus thiooxidans單獨(dú)及混合浸出黃銅礦過程中細(xì)菌硫氧化、鐵氧化情況。同時利用XRD、硫的K邊X射線吸收近邊結(jié)構(gòu)光譜(XANES)等分析手段研究3種細(xì)菌單獨(dú)/混合浸出黃銅礦過程中礦物組成成分和礦物表面硫的形態(tài)變化。結(jié)果表明：在浸出初期電位低于400 mV (vs SCE)時，黃銅礦的浸出速率較快，此后電位迅速升高至540 mV，黃銅礦浸出速率明顯變慢。混合菌浸出時體系的硫/鐵氧化活性較單一菌高，根據(jù)XANES擬合分析發(fā)現(xiàn)，混合菌浸出時礦物表面元素硫及黃鉀鐵礬積累量明顯減少，浸出初期輝銅礦產(chǎn)量明顯高于單一細(xì)菌浸出的。
關(guān)鍵字: 硫氧化；X射線吸收近邊結(jié)構(gòu)光譜(XANES)；黃銅礦；硫形態(tài)
（1. Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China;
2. School of Mineral Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The sulfur/iron oxidation activities of three typical mesosphilic bioleaching bacteria, such as Acidithiobacillus ferrooxidans, Leptospirillum ferriphilum and Acidithiobacillus thiooxidans, were studied and their mixture in bioleaching of chalcopyrite were compared. Meanwhile, the relevant sulfur speciation on the surface of chalcopyrite leached by pure/mixed bacteria was investigated by X-ray diffractometry (XRD) and X ray absorption near-edge structure (XANES). The results show that the dissolution rate of chalcopyrite is higher when the redox potential is less than 400 mV (vs SCE), and above that potential, the dissolution rate of chalcopyrite apparently decreases, the mixed culture has a higher sulfur/ion oxidation activity than that of the pure cultures of bacteria. The fitted results of XANES spectra indicate that the mixed culture promotes the formation of chalcocite and obviously restrain the passivation layer (sulfur and jarosite).
Key words: sulfur-oxidation; X-ray absorption near-edge structure; chalcopyrite; sulfur speciation
