Reactive alumina is a well-established group of raw materials for refractory castables to improve their rheological behavior.In this article the influence of bimodal reactive alumina and standard(<325#)calcined alu...Reactive alumina is a well-established group of raw materials for refractory castables to improve their rheological behavior.In this article the influence of bimodal reactive alumina and standard(<325#)calcined alumina on workability,packing density and strength of alumina based castables is examined.It will be shown that there is a significant effect on water demand and apparent density of the castable,which is depending on the percentage of reactive alumina on the one hand and on the type of reactive alumina on the other hand.The effect of the alumina on setting time and cold crushing strength has shown to be insignificant in this set of experiments.展开更多
Regarding the morphology of alumina,effect of the heredity of raw materials on properties of aluminamagnesia refractory castables was investigated by adding platelet alumina as the specific template.In-situ spinel pla...Regarding the morphology of alumina,effect of the heredity of raw materials on properties of aluminamagnesia refractory castables was investigated by adding platelet alumina as the specific template.In-situ spinel platelet formed derived from platelet alumina.By comparing phase evolution,apparent porosity,bulk density,permanent linear expansion and strength,it was demonstrated that the utilization of the microstructures＇ heredity of platelet alumina was a new alternative for controlling properties of alumina-magnesia refractory castables.展开更多
An approach was developed to upgrade the bauxite ore by molecular hydrogen and hydrogen plasma. A gibbsite-type bauxite sample was obtained from National Aluminium Company（NALCO）, Odisha, India. The obtained sample ...An approach was developed to upgrade the bauxite ore by molecular hydrogen and hydrogen plasma. A gibbsite-type bauxite sample was obtained from National Aluminium Company（NALCO）, Odisha, India. The obtained sample was crushed and sieved（to 100 μm） prior to the chemical analysis and grain-size distribution study. The bauxite sample was calcined in the temperature range from 500 to 700°C for different time intervals to optimize the conditions for maximum moisture removal. This process was followed by the reduction of the calcined ore by molecular hydrogen and hydrogen plasma. Extraction of alumina from the reduced ore was carried out via acid leaching in chloride media for 2 h at 60°C. X-ray diffraction, scanning electron microscopy, thermogravimetry in conjunction with differential scanning calorimetry, and Fourier transform infrared spectroscopy were used to determine the physicochemical characteristics of the material before and after extraction. Alumina extracted from the reduced ore at the optimum calcination temperature of 700°C and the optimum calcination time of 4 h is found to be 90% pure.展开更多
文摘Reactive alumina is a well-established group of raw materials for refractory castables to improve their rheological behavior.In this article the influence of bimodal reactive alumina and standard(<325#)calcined alumina on workability,packing density and strength of alumina based castables is examined.It will be shown that there is a significant effect on water demand and apparent density of the castable,which is depending on the percentage of reactive alumina on the one hand and on the type of reactive alumina on the other hand.The effect of the alumina on setting time and cold crushing strength has shown to be insignificant in this set of experiments.
基金supported by the Natural Science Foundation of China under Grant No.51502214
文摘Regarding the morphology of alumina,effect of the heredity of raw materials on properties of aluminamagnesia refractory castables was investigated by adding platelet alumina as the specific template.In-situ spinel platelet formed derived from platelet alumina.By comparing phase evolution,apparent porosity,bulk density,permanent linear expansion and strength,it was demonstrated that the utilization of the microstructures＇ heredity of platelet alumina was a new alternative for controlling properties of alumina-magnesia refractory castables.
基金National Aluminium Company (NALCO) for financial support
文摘An approach was developed to upgrade the bauxite ore by molecular hydrogen and hydrogen plasma. A gibbsite-type bauxite sample was obtained from National Aluminium Company（NALCO）, Odisha, India. The obtained sample was crushed and sieved（to 100 μm） prior to the chemical analysis and grain-size distribution study. The bauxite sample was calcined in the temperature range from 500 to 700°C for different time intervals to optimize the conditions for maximum moisture removal. This process was followed by the reduction of the calcined ore by molecular hydrogen and hydrogen plasma. Extraction of alumina from the reduced ore was carried out via acid leaching in chloride media for 2 h at 60°C. X-ray diffraction, scanning electron microscopy, thermogravimetry in conjunction with differential scanning calorimetry, and Fourier transform infrared spectroscopy were used to determine the physicochemical characteristics of the material before and after extraction. Alumina extracted from the reduced ore at the optimum calcination temperature of 700°C and the optimum calcination time of 4 h is found to be 90% pure.
