發(fā)電浸出的機制
(1. 中南大學 化學化工學院，長沙410083；
2. 中南大學 資源加工及生物工程學院，長沙410083；
3. 湖南工業(yè)大學 冶金學院，株洲412000)
摘 要: 采用雙電池體系研究發(fā)電浸出過程和生物發(fā)電浸出過程中放電量、Fe2+和Mn2+浸出率與時間的關(guān)系。結(jié)果表明：生物發(fā)電浸出的Cu2+和Fe2+浸出率比單純發(fā)電浸出提高近2倍，發(fā)電量和Mn2+浸出率提高近3倍。對發(fā)電浸出產(chǎn)物進行XRD和SEM分析表明，經(jīng)歷發(fā)電浸出過程，晶體的形貌與反應前相似，發(fā)電浸出產(chǎn)物單質(zhì)硫和雜質(zhì)PbS大量存在；經(jīng)歷生物發(fā)電浸出過程，雜質(zhì)PbS被氧化成PbSO4，沉積在殘渣表面。對氧化硫硫桿菌作用下CuFeS2-MnO2發(fā)電浸出機制研究表明，黃銅礦的發(fā)電浸出和生物發(fā)電浸出都存在表層的黃銅礦離解產(chǎn)生Cu2+、Fe2+和單質(zhì)硫的過程，而生物發(fā)電浸出中還進行了單質(zhì)硫部分被A.t菌氧化的后續(xù)過程，且生物氧化過程為控制步驟。MnO2的浸出在本研究的系統(tǒng)中是被動的，如果黃銅礦的浸出還能進行，MnO2的浸出就能持續(xù)。
關(guān)鍵字: 黃銅礦；二氧化錳；生物氧化；發(fā)電浸出
（1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China;
3. Metallurgic College, Hunan Industrial University, Zhuzhou 412000, China）
Abstract:A dual cell system was used to study the relationship between time and electric quantity, dissolved Cu2+, Fe2+ and Mn2+ ratio in the process of electro-generative simultaneous leaching (EGSL) and bio-electro-generative simultaneous leaching (BEGSL). The results show that the dissolved Cu2+ and Fe2+ ratios in BEGSL are increased by almost 2 times, and the dissolved Mn2+ ratio and the electric quantity output in BEGSL are nearly 3 times more than those in EGSL. The oxidation debris for chalcopyrite characterized by XRD and TEM indicate that the crystal pattern is similar to that of the raw ore in EGSL. The impurity PbS is oxidized to insoluble PbSO4 in BEGSL. The reaction mechanism of CuFeS2-MnO2 in the presence of Acidithiobacillus thiooxidans (A. thiooxidans) could be supposed as a successive reaction of two independent sub-processes. The stage both in EGSL and in BEGSL is the dissolution of chalcopyrite on the surface to Cu2+, Fe2+ and sulfur; and the accumulated sulfur is oxidized by A. thiooxidans in the following procedure in BEGSL. The latter is controlling step in BEGL. The leaching of MnO2 in this system is dependent on the leaching of chalcopyrite. If the reaction of chalcopyrite can be performed, the reaction of MnO2 will continue.
Key words: chalcopyrite; MnO2; bio-oxidation; electro-generative leaching
