摘要：
<jats:title>Abstract</jats:title>
<jats:p>In order to study the waste cathode ray tube glass fine aggregate (particle size < 0.15 mm) on barite concreteperformance, the waste cathode ray tube glass fine aggregate is blended into the barite concrete at 0%, 4%, 6%, 8%, and 10% of the mass of the barite sand quality to conduct experimental research on the related properties of barite concrete. The experimental results show that when the amount of waste cathode ray tube glass fine aggregate is 6%∼8%, the prepared barite concrete has the best working performance. The slump expansion reaches 560mm×560mm, and the 28d cube compressive strength is 37.76MPa. The V-box passage time is 17.56s, and barite concrete has the best shielding gamma ray capability.</jats:p>
摘要：
Microbial grouting reinforcement technology can improve the strength of tailings to a certain extent, but there is still much room for improvement. To balance the adverse effects of the technology to cure the tailings, this paper introduced the mineralization technology of soft template into the microbial induced calcium carbonate precipitation (MICP), and carried out the experiments on microbial grouting to strengthen the tailings under the control of organic matrix. The results of aqueous solution test showed that the organic matrix can significantly regulate the structural characteristics of calcium carbonate. When the added organic matrix is egg white protein with a volume fraction of 20%, the contribution to the conversion rate of calcium ions in the reaction solution was the largest, and the concentration of calcium ions in the solution at 20 h is reduced by about 83.72% compared with the control group. In the solidification test of tailings, as the egg white concentration increased, the curing unevenness of the tailings was further aggravated. When the egg white volume fraction is 5%, the strength improvement effect of the tailings was the best and the dilatancy characteristic was the most significant. At the same time, the calcium carbonate produced are mostly large-sized calcite, and the corresponding formation amount, cohesive force and internal friction angle are 16.01%, 131.98 kPa and 42.7 degrees, respectively. The study showed that mineralization technology of soft template can promote the MICP technology, which provides a new method for the reinforcement of tailings dam. (C) 2020 The Author(s). Published by Elsevier Ltd.
作者机构：
[伍玲玲; 张志军; 喻清; 潘宇翔; 胡林] School of Nuclear Resources Engineering, University of South China, Hengyang;Hunan;421001, China;Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang;[伍玲玲; 张志军; 喻清; 潘宇翔; 胡林] Hunan
通讯机构：
School of Nuclear Resources Engineering, University of South China, Hengyang, Hunan, China
通讯机构：
[Ding, De-xin] C;[Ding, DX; Zhang, ZJ] U;Cent South Univ, Sch Resources & Safety Engn, Changsha 420083, Hunan, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Mi, Hengyang 421001, Hunan, Peoples R China.;Univ South China, Nucl Resource Engn Coll, Hengyang 421001, Hunan, Peoples R China.
摘要：
<jats:p>The sand columns inoculated with the indigenous microorganism (<jats:italic>Aspergillus niger</jats:italic>) were used to investigate the effect of bioclogging during the radioactive effluent percolation. The hydraulic gradient, volumetric flow rate, and uranyl ions concentration were monitored over time. The sand columns were operated with continuous radioactive effluent of uranium tailings reservoir. After 68 days, the hydraulic conductivity of the sand columns decreased more than 72%, and the adsorption rate of uranyl ions by <jats:italic>Aspergillus niger</jats:italic> reached more than 90%. Environmental scanning electron microscope imaging confirmed the biofilm covering the surface of sand particles and connecting sand particles together, which resulted in a reduction of hydraulic conductivity. The results indicated that the propagation of <jats:italic>Aspergillus niger</jats:italic> can clog the seepage channel and effectively adsorb the uranyl ions of radioactive effluent in the porous media, which provides a suitable measure for controlling the migration of radioactive effluent of uranium tailings reservoir into the subsurface environment.</jats:p>
作者机构：
[章求才; 贺桂成; 张志军] School of Nuclear Resources Engineering, University of South China, Hengyang;Hunan;421001, China;[黄炳香] State Key Laboratory of Coal Resources and Safe Mining, China University of Mining & Technology, Xuzhou;Jiangsu
通讯机构：
[He, G.] S;School of Nuclear Resources Engineering, China
通讯机构：
[Zhang, Zhi-jun] U;Univ South China, Nucl Resource Engn Coll, Hengyang 421001, Hunan, Peoples R China.
摘要：
<jats:p><jats:italic>Sporosarcina Pasteurii</jats:italic> was chosen for the experiment to study the effect and mechanism of fine-grained uranium tailings reinforced by MICP. The biochemical characteristics of strains and microbial immobilization in uranium tailings were analyzed. The results showed that the CaCO<jats:sub>3</jats:sub> production rate is positively correlated with the physiological activity of <jats:italic>Sporosarcina Pasteurii</jats:italic> and the concentration of calcium sources, and the higher the solution concentration of CaCl<jats:sub>2</jats:sub>, the lower the discharge rate of bacterial liquid from the sand column, but high concentration of CaCl<jats:sub>2</jats:sub> solution will affect the uniform distribution and migration of bacteria in the uranium tailings. After 16 days, the direct shear was used to test the reinforcement effects of fine-grained uranium tailings by MICP. The cohesive force and the internal friction angle of fine-grained uranium tailings were increased by 140.1% and 46.7%. The production amount of CaCO<jats:sub>3</jats:sub> is 138.89 kg/m<jats:sup>3</jats:sup>. The results showed that the MICP-reinforced technology can effectively improve the shear strength of the uranium tailings, and the experiment provides a new method for the reinforcement of the fine-grained uranium tailings dam.</jats:p>
作者机构：
[章求才; 田亚坤; 刘永; 张志军; 贺桂成] School of Nuclear Resources Engineering, University of South China, Hengyang, 421001, China;[李亚俊] Hunan Nonferrous Metallurgy Labor Protection Research Institute, Changsha, 410000, China;[刘玄钊] Lu'an Group, Changzhi, 046000, China
通讯机构：
School of Nuclear Resources Engineering, University of South China, Hengyang, China
作者机构：
[贺桂成; 张志军; 丁德馨] School of Nuclear Resources Engineering, University of South China, Hengyang;Hunan;421001, China;[刘生龙; 黄炳香] School of Mines, China University of Mining & Technology, Xuzhou;Jiangsu
通讯机构：
[Ding, D.] S;School of Nuclear Resources Engineering, China
