Zheng Xing-Fu, Xia Jin-Lan, Nie Zhen-Yuan, Cao Hong-Peng, Hu Rui-Jia, Liang Yu-Ting, Liu Hong-Chang
School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
Guangxi Academy of Sciences, Nanning, China.
Front Microbiol. 2025 Jan 21;16:1475572. doi: 10.3389/fmicb.2025.1475572. eCollection 2025.
Stibnite (SbS) is an important but difficult to biologically leach mineral, so it is important to find a potential scheme for improving the bioleaching rate of SbS. In this study, by combining experiments and first-principles density functional theory (DFT) calculations, the impact and related mechanisms of pyrite (FeS) on stibnite (SbS) bioleaching were studied for the first time. The bioleaching results revealed that FeS obviously improved the SbS bioleaching rate, and in the 0.5FeS:0.5CuFeS system, the bioleaching rate of SbS increased from 2.23 to 24.6%, which was the best mass mixing ratio. The XPS and XANES results revealed that during the bioleaching process, SbS was transformed to SbO and SbO. The electrochemical results revealed that after FeS was mixed, a FeS-SbS galvanic cell formed, which promoted the electron transfer efficiency and redox reaction of SbS. The DFT results show that between the SbS (0 1 0) and FeS (1 0 0) surfaces, S-Fe, S-S, S-Sb, and Sb-Fe bonds are formed, and the direction of electron transfer is from SbS to FeS; the work functions for SbS after addition of FeS decrease, implying that faster electron transfer occurs; Fe(III)-6HO derived from FeS adsorbs on the surface more easily than does glucose, which is the major component of the extracellular polymeric substances in bacteria, indicating that during the bioleaching process, Fe(III)-6HO plays an important role; after mixing, both Fe(III)-6HO and glucose adsorb on the SbS (0 1 0) surface more easily, with stronger bonds and larger adsorption energies, which are in good agreement with the experimental results.
辉锑矿（SbS）是一种重要但难以进行生物浸出的矿物，因此找到提高辉锑矿生物浸出率的潜在方案具有重要意义。在本研究中，通过结合实验和第一性原理密度泛函理论（DFT）计算，首次研究了黄铁矿（FeS）对辉锑矿（SbS）生物浸出的影响及相关机制。生物浸出结果表明，FeS显著提高了SbS的生物浸出率，在0.5FeS:0.5CuFeS体系中，SbS的生物浸出率从2.23%提高到24.6%，这是最佳的质量混合比。XPS和XANES结果表明，在生物浸出过程中，SbS转化为SbO和SbO。电化学结果表明，FeS混合后形成了FeS-SbS原电池，促进了SbS的电子转移效率和氧化还原反应。DFT结果表明，在SbS（0 1 0）和FeS（1 0 0）表面之间形成了S-Fe、S-S、S-Sb和Sb-Fe键，电子转移方向是从SbS到FeS；添加FeS后SbS的功函数降低，这意味着发生了更快的电子转移；FeS衍生的Fe(III)-6HO比细菌胞外聚合物的主要成分葡萄糖更容易吸附在表面，这表明在生物浸出过程中，Fe(III)-6HO起着重要作用；混合后，Fe(III)-6HO和葡萄糖都更容易吸附在SbS（0 1 0）表面，键更强，吸附能更大，这与实验结果吻合良好。
