ISSN: 1003-6326
CN: 43-1239/TG

Vol. 29    No. 10    October 2019

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Effect of temperature-induced phase transitions on bioleaching of chalcopyrite
Ke-xin CHANG, Yan-sheng ZHANG, Jia-ming ZHANG, Teng-fei LI, Jun WANG, Wen-qing QIN
(School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China)
Abstract: The phase transformation of chalcopyrite and the effect of its phase status on bacterial leaching were studied. Under the protection of high-purity argon, different temperatures (203, 382 and 552 °C) were applied to natural chalcopyrite to complete the phase change. In addition, the chalcopyrite was bioleached before and after the phase change. The results show that the chalcopyrite heated at 203 and 382 °C remained in the α phase, whereas the chalcopyrite changed from α to β phase at 552 °C. The leaching rates of chalcopyrite after the phase transitions at 203, 382 and 552 °C were 32.9%, 40.5% and 60.95%, respectively. Further, the crystal lattice parameters of chalcopyrite increased and lattice energy decreased, which were the fundamental reasons for the significant increase in leaching rate. Electrochemical experiments demonstrated that with increasing annealing temperature, the polarization resistance decreased and corrosion current density increased. The higher the oxidation rate was, the higher the leaching rate was.
Key words: lattice parameter; chalcopyrite; phase transition; bioleaching; electrochemistry
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
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