The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan...The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan were studied in terms of their ability to become cementitious materials. Compound thermal activation was used to improve the cementitious properties of the tailings, while analyzing methods, such as X-ray diffraction （XRD）, infrared spectroscopy （IR）, nuclear magnetic resonance （NMR）, and X-ray photoelectron spectrometer （XPS）, were employed to study the changes in phase and structure under different activation conditions. The results reveal clear relationships between the binding energies of Si2p and O 1 s, polymerization degree, and cementitious activity of iron ore tailings.展开更多
The oil crisis has prompted renewed interest in direct burning of oil shale as an alternative energy source. A major problem in this process is the large portion of ash produced. The cementing properties of this ash w...The oil crisis has prompted renewed interest in direct burning of oil shale as an alternative energy source. A major problem in this process is the large portion of ash produced. The cementing properties of this ash were investi-gated to determine its applicability as a building material. By means of XRD,IR,NMR and ICP,we have studied the effects of burning temperature on the reactivity of ash. Maximum reactivity was obtained with ash samples produced at 700℃ to 900℃. In this range,the strength of oil-shale-based material,with properties similar to cement,which is composed of oil shale and several other kinds of solid wastes,can achieve the standard of 42.5^# cement. Our study has provided an experimental foundation and theoretical base for a massive utilization of oil shale.展开更多
A new method for estimating the degree of [SiO4]4-polymerization of coal gangue is presented. The method uses the relative bridging oxygen number (RBO) based on nuclear magnetic resonance (NMR) techniques. X-ray diffr...A new method for estimating the degree of [SiO4]4-polymerization of coal gangue is presented. The method uses the relative bridging oxygen number (RBO) based on nuclear magnetic resonance (NMR) techniques. X-ray diffraction (XRD) and 29Si NMR techniques have been used to study phase transitions and silicate polymerization of coal gangue calcined at different temperatures or co-calcined. It has been found that phase transition of clay minerals causes silicate polymerization to change with temperature. In this study, cementing activity and RBO were determined to be inversely related. Generally, activated coal gangue with lower RBO had better cementitious activity.展开更多
基金supported by the National Natural Science Foundation of China (No.50674062)the Key Project of the Ministry of Railway of China (No.2008G031-N)the Postdoctoral Science Foundation (No.20070420354)
文摘The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan were studied in terms of their ability to become cementitious materials. Compound thermal activation was used to improve the cementitious properties of the tailings, while analyzing methods, such as X-ray diffraction （XRD）, infrared spectroscopy （IR）, nuclear magnetic resonance （NMR）, and X-ray photoelectron spectrometer （XPS）, were employed to study the changes in phase and structure under different activation conditions. The results reveal clear relationships between the binding energies of Si2p and O 1 s, polymerization degree, and cementitious activity of iron ore tailings.
基金Projects 50674062 supported by the National Natural Science Foundation of China2006BAC21B03 by the National Key Technologies R&D Program
文摘The oil crisis has prompted renewed interest in direct burning of oil shale as an alternative energy source. A major problem in this process is the large portion of ash produced. The cementing properties of this ash were investi-gated to determine its applicability as a building material. By means of XRD,IR,NMR and ICP,we have studied the effects of burning temperature on the reactivity of ash. Maximum reactivity was obtained with ash samples produced at 700℃ to 900℃. In this range,the strength of oil-shale-based material,with properties similar to cement,which is composed of oil shale and several other kinds of solid wastes,can achieve the standard of 42.5^# cement. Our study has provided an experimental foundation and theoretical base for a massive utilization of oil shale.
基金Project supported by the National Natural Science Foundation of China (No. 50674062)the Key Projects in the National Science & Technology Pillar Program (No. 2006BAC21B03)the Beijing Science and Technology Plan Projects of China (No. D07040300690000)
文摘A new method for estimating the degree of [SiO4]4-polymerization of coal gangue is presented. The method uses the relative bridging oxygen number (RBO) based on nuclear magnetic resonance (NMR) techniques. X-ray diffraction (XRD) and 29Si NMR techniques have been used to study phase transitions and silicate polymerization of coal gangue calcined at different temperatures or co-calcined. It has been found that phase transition of clay minerals causes silicate polymerization to change with temperature. In this study, cementing activity and RBO were determined to be inversely related. Generally, activated coal gangue with lower RBO had better cementitious activity.
