The effects of aggressive peat nature (pH) on the strength of peat treated by cement and cement-sodium silicate grout were investigated by evaluating the changes in unconfined compressive strength,moisture content,and...The effects of aggressive peat nature (pH) on the strength of peat treated by cement and cement-sodium silicate grout were investigated by evaluating the changes in unconfined compressive strength,moisture content,and scanning electron microscopy (SEM) of samples with time in different pH media.The results indicate that peats treated by cement-silicate have higher strength than peats treated by cement,due to an increase in pH value of the media.Furthermore,cement and cement-silicate are highly effective in reducing the moisture content and void ratio of the treated peats.The microstructures of treated peats support the laboratory test results.展开更多
Mine grouting reinforcement and water plugging projects often require large amounts of grouting materials.To reduce the carbon emission of grouting material production,improve the utilization of solid waste from minin...Mine grouting reinforcement and water plugging projects often require large amounts of grouting materials.To reduce the carbon emission of grouting material production,improve the utilization of solid waste from mining enterprises,and meet the needs of mine reinforcement and seepage control,a double-liquid grouting material containing a high admixture of coal gangue powder/bottom ash geopolymer was studied.The setting time,fluidity,bleeding rate,and mechanical properties of grouting materials were studied through laboratory tests,and SEM analyzed the microstructure of the materials.The results show that the total mixture of calcined gangue does not exceed 60%.And the proportion of bottom ash replacing cement should be within 30%.At the same time,the volume mixture of sodium silicate is 20%.And the water-solid ratio does not exceed 0.6.The stability of the slurry prepared under this ratio is good.The microstructure of the stone body is dense,and its strength can meet the requirements of rock reinforcement and seepage control.Its economic and environmental benefits are more significant than the traditional cement-silicate double-liquid grouting material.展开更多
Proper room and pillar sizes are both critical factors for safe mining and high ore recovery rate in shrinkage stoping mining of underground metal mines. The rock masses of Tangdan copper mine of China are fractured, ...Proper room and pillar sizes are both critical factors for safe mining and high ore recovery rate in shrinkage stoping mining of underground metal mines. The rock masses of Tangdan copper mine of China are fractured, which needs much reinforcement and support prior to mining. Cement-sodium silicate grout technology was selected, then its related parameters such as grout pressure, diffusion radius and time were calculated and proposed. In order to test the effect of the pressured grout in the fractured No.4 ore block, field experiments were conducted. To optimize stoping configuration, three-dimensional numerical simulation with ANSYS and FLAC 3 D softwares was proposed. The results show that the drilling porosity and mechanical properties of the rock masses are increased obviously. After grout, ore recovery rate is increased by 10.2 % employing the newly designed stoping configuration compared with the previous. Last, analyzed from the surface movements, roof subsidence and the maximum principal stress of the pillars, the mining safety is probable of being ensured.展开更多
利用水玻璃作为浆液主剂,对复合浆液的胶凝时间、黏度、抗压强度、水质毒理、SEM、IR、29Si NMR分别进行了研究。试验结果表明:新型复合浆液能实现浆液的胶凝时间可调、黏度低、固砂体力学性能较高的特点;浆液的水质毒理性能表现较为良...利用水玻璃作为浆液主剂,对复合浆液的胶凝时间、黏度、抗压强度、水质毒理、SEM、IR、29Si NMR分别进行了研究。试验结果表明:新型复合浆液能实现浆液的胶凝时间可调、黏度低、固砂体力学性能较高的特点;浆液的水质毒理性能表现较为良好;SEM分析得知浆液胶结情况良好;IR及29 Si NMR分析证实,反应产生了硅酸盐的聚合产物。展开更多
基金the Ministry of Science,Technology Innovation,Malaysia (Project No.03-01-04-SF0889) for the financial support of this research
文摘The effects of aggressive peat nature (pH) on the strength of peat treated by cement and cement-sodium silicate grout were investigated by evaluating the changes in unconfined compressive strength,moisture content,and scanning electron microscopy (SEM) of samples with time in different pH media.The results indicate that peats treated by cement-silicate have higher strength than peats treated by cement,due to an increase in pH value of the media.Furthermore,cement and cement-silicate are highly effective in reducing the moisture content and void ratio of the treated peats.The microstructures of treated peats support the laboratory test results.
基金Funding Statement:The research described in this paper was financially supported by the National Natural Science Foundation of China(No.51974172)Innovation and Technology Program of Universities in Shandong Province,China(No.2020KJH001)+1 种基金National Natural Science Foundation of China(No.52274131)State Key Laboratory of Coal Mining and Clean Utilization(No.2021-CMCU-KF017).
文摘Mine grouting reinforcement and water plugging projects often require large amounts of grouting materials.To reduce the carbon emission of grouting material production,improve the utilization of solid waste from mining enterprises,and meet the needs of mine reinforcement and seepage control,a double-liquid grouting material containing a high admixture of coal gangue powder/bottom ash geopolymer was studied.The setting time,fluidity,bleeding rate,and mechanical properties of grouting materials were studied through laboratory tests,and SEM analyzed the microstructure of the materials.The results show that the total mixture of calcined gangue does not exceed 60%.And the proportion of bottom ash replacing cement should be within 30%.At the same time,the volume mixture of sodium silicate is 20%.And the water-solid ratio does not exceed 0.6.The stability of the slurry prepared under this ratio is good.The microstructure of the stone body is dense,and its strength can meet the requirements of rock reinforcement and seepage control.Its economic and environmental benefits are more significant than the traditional cement-silicate double-liquid grouting material.
基金Projects(51374034,51674012) supported by the National Natural Science Foundation of ChinaProject(2013BAB02B05) supported by the China National Science and Technology Support Program during the 12th Five-Year Plan Period
文摘Proper room and pillar sizes are both critical factors for safe mining and high ore recovery rate in shrinkage stoping mining of underground metal mines. The rock masses of Tangdan copper mine of China are fractured, which needs much reinforcement and support prior to mining. Cement-sodium silicate grout technology was selected, then its related parameters such as grout pressure, diffusion radius and time were calculated and proposed. In order to test the effect of the pressured grout in the fractured No.4 ore block, field experiments were conducted. To optimize stoping configuration, three-dimensional numerical simulation with ANSYS and FLAC 3 D softwares was proposed. The results show that the drilling porosity and mechanical properties of the rock masses are increased obviously. After grout, ore recovery rate is increased by 10.2 % employing the newly designed stoping configuration compared with the previous. Last, analyzed from the surface movements, roof subsidence and the maximum principal stress of the pillars, the mining safety is probable of being ensured.
文摘利用水玻璃作为浆液主剂,对复合浆液的胶凝时间、黏度、抗压强度、水质毒理、SEM、IR、29Si NMR分别进行了研究。试验结果表明:新型复合浆液能实现浆液的胶凝时间可调、黏度低、固砂体力学性能较高的特点;浆液的水质毒理性能表现较为良好;SEM分析得知浆液胶结情况良好;IR及29 Si NMR分析证实,反应产生了硅酸盐的聚合产物。
