Based on the working principles of particle bed comminution, particles produced by high-pressure grinding rolls （HPGR） have surface properties different from particles produced by other grinding patterns, which exer...Based on the working principles of particle bed comminution, particles produced by high-pressure grinding rolls （HPGR） have surface properties different from particles produced by other grinding patterns, which exert great influence on mineral flotation. Flotation performances of calcite particles under different grinding patterns involving the use of HPGR, a jaw crusher, a dry ball mill, a wet ball mill, and a wet rod mill were studied using single mineral flotation tests. The surface properties of the particles under different grinding patterns were characterized to determine the flotation performance variation in terms of specific surface area, particle size distribution, AFM, XPS, and zeta potential. The results show that particles ground by HPGR exhibited improved flotation performance within the lower range of grinding fineness in both NaOL and dodecyl amine flotation systems compared to the particles prepared using other grinding patterns. Specific surface area, particle size distribution, surface roughness, Fe（III） contamination, binding energy, and zeta potential are greatly influenced by grinding patterns, which is the main cause of the flotation performance variation.展开更多
The relationship among the surface fissure ratio, moisture content, seepage coefficient and deformation modulus of field unsaturated expansive soil in Nanning, Guangxi Province, China, was obtained by a direct or indi...The relationship among the surface fissure ratio, moisture content, seepage coefficient and deformation modulus of field unsaturated expansive soil in Nanning, Guangxi Province, China, was obtained by a direct or indirect method. Digital images of expansive soil of the surface fissure with different moisture contents were analyzed with the binarization statistic method. In addition, the fissure fractal dimension was computed with a self-compiled program. Combined with in situ seepage and loading plate tests, the relationship among the surface fissure ratio, moisture content, seepage coefficient and deformation modulus was initially established. The surface fissure ratio and moisture content show a linear relation, ＂y=-0.019 1x＋1.028 5＂ for rufous expansive soil and ＂y=-0.07 1x＋2.610 5＂ for grey expansive soil. Soil initial seepage coefficient and surface fissure ratio show a power function relation, ＂y=1× 10^-9exp（15.472x）＂ for rufous expansive soil and ＂y=5× 10^-7exp（4.209 6x）＂ for grey expansive soil. Grey expansive soil deformation modulus and surface fissure ratio show a power fimction relation of ＂y=3.935 7exp（0.993 6x）＂. Based on the binarization and fractal dimension methods, the results show that the surface fissure statistics can depict the fissure distribution in the view of two dimensions. And the evolvement behaviors of permeability and the deformation modulus can indirectly describe the developing state of the fissure. The analysis reflects that the engineering behaviors of unsaturated expansive soil are objectively influenced by fissure.展开更多
基金Project(2013EG132088)supported by Special Program for Research Institutes of the Ministry of Science and Technology,ChinaProject(12010402c187)supported by Key Science and Technology Program of Anhui Province,ChinaProject(GJKJ-14-89)supported by Science and Technology Program of Nanchang Institute of Science and Technology,China
文摘Based on the working principles of particle bed comminution, particles produced by high-pressure grinding rolls （HPGR） have surface properties different from particles produced by other grinding patterns, which exert great influence on mineral flotation. Flotation performances of calcite particles under different grinding patterns involving the use of HPGR, a jaw crusher, a dry ball mill, a wet ball mill, and a wet rod mill were studied using single mineral flotation tests. The surface properties of the particles under different grinding patterns were characterized to determine the flotation performance variation in terms of specific surface area, particle size distribution, AFM, XPS, and zeta potential. The results show that particles ground by HPGR exhibited improved flotation performance within the lower range of grinding fineness in both NaOL and dodecyl amine flotation systems compared to the particles prepared using other grinding patterns. Specific surface area, particle size distribution, surface roughness, Fe（III） contamination, binding energy, and zeta potential are greatly influenced by grinding patterns, which is the main cause of the flotation performance variation.
基金Projects(41102229,51109208)supported by the National Natural Science Foundation of ChinaProject(2011CDB407)supported by Natural Science Foundation of Hubei Province,ChinaProject supported by Qing Lan Project of Jiangsu Province,China
文摘The relationship among the surface fissure ratio, moisture content, seepage coefficient and deformation modulus of field unsaturated expansive soil in Nanning, Guangxi Province, China, was obtained by a direct or indirect method. Digital images of expansive soil of the surface fissure with different moisture contents were analyzed with the binarization statistic method. In addition, the fissure fractal dimension was computed with a self-compiled program. Combined with in situ seepage and loading plate tests, the relationship among the surface fissure ratio, moisture content, seepage coefficient and deformation modulus was initially established. The surface fissure ratio and moisture content show a linear relation, ＂y=-0.019 1x＋1.028 5＂ for rufous expansive soil and ＂y=-0.07 1x＋2.610 5＂ for grey expansive soil. Soil initial seepage coefficient and surface fissure ratio show a power function relation, ＂y=1× 10^-9exp（15.472x）＂ for rufous expansive soil and ＂y=5× 10^-7exp（4.209 6x）＂ for grey expansive soil. Grey expansive soil deformation modulus and surface fissure ratio show a power fimction relation of ＂y=3.935 7exp（0.993 6x）＂. Based on the binarization and fractal dimension methods, the results show that the surface fissure statistics can depict the fissure distribution in the view of two dimensions. And the evolvement behaviors of permeability and the deformation modulus can indirectly describe the developing state of the fissure. The analysis reflects that the engineering behaviors of unsaturated expansive soil are objectively influenced by fissure.
