In situ characterization of natural pyrite bioleaching using electrochemical noise technique

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2016-02, Vol.23 (2), p.117-126
• Main Authors: Chen, Guo-bao, Yang, Hong-ying, Li, Hai-jun
• Format: Article
• Language: English
• Subjects: Bacterial leaching; Ceramics; Characterization and Evaluation of Materials; Chemical reactions; Chemistry and Materials Science; Composites; Corrosion and Coatings; Data analysis; Electrochemical analysis; Electrochemical noise; Electrochemistry; Frequency domains; Glass; Leaching; Materials Science; Metallic Materials; Metallurgy; Natural Materials; Noise; Oxidation; Power spectral density; Pyrite; Reaction mechanisms; Spectra; Sulfuric acid; Surfaces and Interfaces; Thin Films; Tribology; White noise; 三价铁离子; 原位表征; 声技术; 天然; 实验数据分析; 浸出液; 电化学噪声; 黄铁矿
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-016-1218-z

An in situ characterization technique called electrochemical noise（ECN） was used to investigate the bioleaching of natural pyrite.ECN experiments were conducted in four active systems（sulfuric acid,ferric-ion,9k culture medium,and bioleaching solutions）.The ECN data were analyzed in both the time and frequency domains.Spectral noise impedance spectra obtained from power spectral density（PSD）plots for different systems were compared.A reaction mechanism was also proposed on the basis of the experimental data analysis.The bioleaching system exhibits the lowest noise resistance of 0.101 MΩ The bioleaching of natural pyrite is considered to be a bio-battery reaction,which distinguishes it from chemical oxidation reactions in ferric-ion and culture-medium（9k） solutions.The corrosion of pyrite becomes more severe over time after the long-term testing of bioleaching.