Key Laboratory of Ministry of Education for High-Efficient Mining and Safety of Metal, University of Science and Technology Beijing, Beijing 100083, China; School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Key Laboratory of Ministry of Education for High-Efficient Mining and Safety of Metal, University of Science and Technology Beijing, Beijing 100083, China; School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China.
J Hazard Mater. 2021 Jun 5;411:125114. doi: 10.1016/j.jhazmat.2021.125114. Epub 2021 Jan 14.
Tailings used as backfilling material in the presence of mixed bacteria are discussed, and the relationship between mixed bacteria and compressive strength, size variation, water-holding capacity is analyzed in this study. The results illustrate a strong improving response of mixed bacteria with enhanced compressive strength, small size variation and low water-holding capacity of cemented tailings backfill (CTB) specimens. The binder dosage and mixed bacteria proportion have great influence on CTB specimens, which indicate that with the increase of mixed bacteria proportion and binder dosage, compressive strength increased obviously. The maximum compressive strength (4.01 MPa) is obtained in the presence of 100.00% mixed bacteria in contrast to only 2.79 MPa in its absence. Samples added high mixed bacteria proportion yield low water-holding capacity and small size variation. 16S rDNA analysis illustrates that bacteria community is influenced significantly during experiment. Further, possible reaction mechanism is proposed suggesting the possible role of mixed bacteria as promoter to form precipitation (KFe(SO)(OH), (NH)Fe(SO)(OH) and (KHO)Fe(SO)(OH)), which reduces tiny cracks in CTB specimens. The technique of using mixed bacteria to reduce binder consumption in this study shows economic benefits to some extent.
本文讨论了混合菌存在时用作回填材料的尾矿，并分析了混合菌与抗压强度、尺寸变化、持水能力之间的关系。结果表明，混合菌对胶结尾矿回填（CTB）试件的抗压强度、尺寸变化小、持水能力低有很强的改善作用。粘结剂用量和混合菌比例对 CTB 试件有很大的影响，表明随着混合菌比例和粘结剂用量的增加，抗压强度明显提高。在 100.00%混合菌的存在下，获得了最大的抗压强度（4.01 MPa），而在不存在混合菌的情况下，仅获得 2.79 MPa。添加高比例混合菌的样品具有低持水能力和小的尺寸变化。16S rDNA 分析表明，在实验过程中细菌群落受到了显著影响。此外，提出了可能的反应机制，表明混合菌可能作为促进剂形成沉淀（KFe(SO)(OH)、(NH)Fe(SO)(OH) 和 (KHO)Fe(SO)(OH)），从而减少 CTB 试件中的微小裂缝。本研究中使用混合菌来减少粘结剂消耗的技术在一定程度上显示了经济效益。
