The co-reduction roasting and grinding-magnetic separation of seaside titanomagnetite and blast furnace dust was investigated with and without fluorite addition at a reduction roasting temperature of 1250°C for 6...The co-reduction roasting and grinding-magnetic separation of seaside titanomagnetite and blast furnace dust was investigated with and without fluorite addition at a reduction roasting temperature of 1250°C for 60 min, a grinding fineness of-43 μm accounting for 69.02 wt% of the total, and a low-intensity magnetic field strength of 151 kA/m. The mineral composition, microstructure, and state of the roasted products were analyzed, and the concentrations of CO and CO_2 were analyzed in the co-reduction roasting. Better results were achieved with a small fluorite dosage(≤4 wt%) in the process of co-reduction. In addition, F^- was found to reduce the melting point and viscosity of the slag phase because of the high content of aluminate and silicate minerals in the blast furnace dust. The low moisture content of the blast furnace dust and calcic minerals inhibited the hydrolysis of CaF_2 and the loss of F^-. Compared with the blast furnace dust from Chengdeng, the blast furnace dusts from Jiugang and Jinxin inhibited the diffusion of F-when used as reducing agents, leading to weaker effects of fluorite.展开更多
This article reviews the background,preparation,development and birth stage,and the main content and framework of the new urbanism theory,then understands new urbanism from a historical perspective and then discusses ...This article reviews the background,preparation,development and birth stage,and the main content and framework of the new urbanism theory,then understands new urbanism from a historical perspective and then discusses how the seaside project in Florida developed a smalltown community with a strong community atmosphere and a beautiful environment,guided by the theory of New Urbanism.This is followed by an in-depth analysis of the high construction and maintenance costs ofNew Urbanism in practice,the impact on the privacy of residents9 lives,the relative reduction of community ties,and other problems,and finally,it gives opinions on the sustainable development of the New Urbanism theory in the future.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 51474018)
文摘The co-reduction roasting and grinding-magnetic separation of seaside titanomagnetite and blast furnace dust was investigated with and without fluorite addition at a reduction roasting temperature of 1250°C for 60 min, a grinding fineness of-43 μm accounting for 69.02 wt% of the total, and a low-intensity magnetic field strength of 151 kA/m. The mineral composition, microstructure, and state of the roasted products were analyzed, and the concentrations of CO and CO_2 were analyzed in the co-reduction roasting. Better results were achieved with a small fluorite dosage(≤4 wt%) in the process of co-reduction. In addition, F^- was found to reduce the melting point and viscosity of the slag phase because of the high content of aluminate and silicate minerals in the blast furnace dust. The low moisture content of the blast furnace dust and calcic minerals inhibited the hydrolysis of CaF_2 and the loss of F^-. Compared with the blast furnace dust from Chengdeng, the blast furnace dusts from Jiugang and Jinxin inhibited the diffusion of F-when used as reducing agents, leading to weaker effects of fluorite.
文摘This article reviews the background,preparation,development and birth stage,and the main content and framework of the new urbanism theory,then understands new urbanism from a historical perspective and then discusses how the seaside project in Florida developed a smalltown community with a strong community atmosphere and a beautiful environment,guided by the theory of New Urbanism.This is followed by an in-depth analysis of the high construction and maintenance costs ofNew Urbanism in practice,the impact on the privacy of residents9 lives,the relative reduction of community ties,and other problems,and finally,it gives opinions on the sustainable development of the New Urbanism theory in the future.
