Hu Lin, Zheng Huaimiao, Wu Lingling, Zhang Zhijun, Yu Qing, Tian Yakun, He Guicheng
School of Resource & Environment and Safety Engineering, University of South China, Hengyang 421001, China.
Hunan Province Engineering Technology Research Center for Disaster Prediction and Control on Mining Geotechnical Engineering, Hengyang 421001, China.
Materials (Basel). 2023 Jul 29;16(15):5337. doi: 10.3390/ma16155337.
In order to improve the effect of microbial-induced calcium carbonate precipitation (MICP) in tailings reinforcement, sodium citrate, an organic matrix with good water solubility, was selected as the crystal form adjustment template for inducing calcium carbonate crystallization, and the reinforcements of tailings by MICP were conducted in several experiments. The effects of sodium citrate on the yield, crystal form, crystal appearance, and distribution of calcium carbonate were analyzed by MICP solution test; thus, the related results were obtained. These showed that the addition of a proper amount of organic matrix sodium citrate could result in an increment in the yield of calcium carbonate. The growth rate of calcium carbonate reached 22.6% under the optimum amount of sodium citrate, and the crystals of calcium carbonate were diverse and closely arranged. Based on this, the MICP reinforcement test of tailings was carried out under the action of the optimum amount of sodium citrate. The microscopic analysis using CT and other means showed that the calcium carbonate is distributed more uniformly in tailings, and the porosity of samples is significantly reduced by layered scanning analysis. The results of triaxial shear tests showed that adding organic matrix sodium citrate effectively increased the cohesion, internal friction angle, and peak stress of the reinforced tailings. It aims to provide a novel idea, a creative approach, and a method to enhance the reinforcement effect of tailings and green solidification technology in the mining environment.
为提高微生物诱导碳酸钙沉淀（MICP）在尾矿加固中的效果，选择水溶性良好的有机基质柠檬酸钠作为诱导碳酸钙结晶的晶型调整模板，并通过多次实验对尾矿进行MICP加固。通过MICP溶液试验分析柠檬酸钠对碳酸钙产量、晶型、晶体形貌及分布的影响，从而得出相关结果。结果表明，添加适量的有机基质柠檬酸钠可使碳酸钙产量增加。在柠檬酸钠最佳用量下，碳酸钙生长速率达22.6%，且碳酸钙晶体多样且排列紧密。在此基础上，在柠檬酸钠最佳用量作用下进行尾矿的MICP加固试验。采用CT等手段进行微观分析表明，碳酸钙在尾矿中分布更均匀，通过分层扫描分析可知样品孔隙率显著降低。三轴剪切试验结果表明，添加有机基质柠檬酸钠有效提高了加固尾矿的黏聚力、内摩擦角和峰值应力。旨在为提高尾矿加固效果及采矿环境中的绿色固化技术提供新思路、创新方法及手段。
