To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis（the energy spectroscopy, XRD and SEM）, the distribution size of particle of fly ash and cement paste intensity of var...To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis（the energy spectroscopy, XRD and SEM）, the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang＇s fly ash should be ground for 20 min.展开更多
The effect of mineral particle size, pulp potential and category of oxidant on pyrite leaching was studied. The results show that a smaller mineral particle size leads to a higher leaching rate of pyrite, and the opti...The effect of mineral particle size, pulp potential and category of oxidant on pyrite leaching was studied. The results show that a smaller mineral particle size leads to a higher leaching rate of pyrite, and the optimum result with pyrite leaching rate of 2.92% is obtained when mineral particle size is less than 0.037 mm. The pulp potential reflects the leaching process. The increase of pulp potential can improve pyrite leaching. The leaching rate and velocity of pyrite can be enhanced rapidly by adding strong oxidant. The kind and the method of adding oxidant have important effect on the pyrite leaching. Appropriate concentration of Fe3+ can enhance pyrite leaching but the precipitation generated by high concentration of ferric ion covers the surface of pyrites and prevents the leaching process. The leaching rate increases with the constant addition of H2O2.展开更多
基金Funded by the National Natural Science Foundation of China(No.51574055)
文摘To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis（the energy spectroscopy, XRD and SEM）, the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang＇s fly ash should be ground for 20 min.
基金Project(2004CB619204) supported by the National Key Fundamental Research and Development Program of ChinaProjects(50321402, 50574101) supported by the National Natural Science Foundation of China
文摘The effect of mineral particle size, pulp potential and category of oxidant on pyrite leaching was studied. The results show that a smaller mineral particle size leads to a higher leaching rate of pyrite, and the optimum result with pyrite leaching rate of 2.92% is obtained when mineral particle size is less than 0.037 mm. The pulp potential reflects the leaching process. The increase of pulp potential can improve pyrite leaching. The leaching rate and velocity of pyrite can be enhanced rapidly by adding strong oxidant. The kind and the method of adding oxidant have important effect on the pyrite leaching. Appropriate concentration of Fe3+ can enhance pyrite leaching but the precipitation generated by high concentration of ferric ion covers the surface of pyrites and prevents the leaching process. The leaching rate increases with the constant addition of H2O2.
