The activity model of CaO-FeO-SiO_2-MoO_3 quarternary system was establishedaccording to the coexistence theory of slag structure and the reduction thermodynamics of molybdenumoxide was discussed by applying this mode...The activity model of CaO-FeO-SiO_2-MoO_3 quarternary system was establishedaccording to the coexistence theory of slag structure and the reduction thermodynamics of molybdenumoxide was discussed by applying this model. The activities of SiO_2 and MoO_3 decrease, while thatof CaO increases with increasing the basicity of slag. Among SiC, [C] and [Si] reactants, thereducing capability of SiC is the strongest, while that of [C] is the poorest at a high temperature(about 1873 K). It is advantageous to increase the yield of molybdenum by increasing the content of[Si] or [C]. Controlling of basicity of slag can prevent the oxidation loss of molybdenum.展开更多
为了探究不同湿度铁矿石在计量斗内的黏附情况,采用Hertz-Mindlin with JKR模型,利用EDEM对不同湿度铁矿石在计量斗中的运动行为进行仿真分析,探讨不同含水率对铁矿石在计量斗壁面上的黏附影响。结果表明:含水铁矿石的落料速度远小于无...为了探究不同湿度铁矿石在计量斗内的黏附情况,采用Hertz-Mindlin with JKR模型,利用EDEM对不同湿度铁矿石在计量斗中的运动行为进行仿真分析,探讨不同含水率对铁矿石在计量斗壁面上的黏附影响。结果表明:含水铁矿石的落料速度远小于无水矿石,且随着含水率的增加,铁矿石在同一时刻的速度明显下降;经过堆料过程,矿石间及矿石与壁面间的粘结更加紧密,且随含水率的增加,F_(JKR1)与F_(JKR2)的值越大,黏附在壁面上的矿石质量越大。所作研究可为计量斗清堵装置的设计提供一定的理论帮助。展开更多
Magnetizing roasting via a fluidized bed,which was recognized as an efficient method for beneficiation of low-grade iron ores,has attracted much attention in China recently due to the fluctuation of the international ...Magnetizing roasting via a fluidized bed,which was recognized as an efficient method for beneficiation of low-grade iron ores,has attracted much attention in China recently due to the fluctuation of the international iron ore market.In order to examine the effects of magnetic properties on the separability and to optimize the operating parameters,magnetic susceptibility and coercivity of a low-grade hematite after magnetizing reduction and reoxidation under different conditions were investigated.It was found that the magnetic susceptibility of roasted ore increased with reduction degree and particle diameter to different degrees.The magnetite was re-oxidized to maghemite when the temperature was below 400℃,and the magnetic susceptibility decreased slightly.The recovery efficiency decreased notably with the particle size for very fine grains although no significant change was found in magnetic susceptibility.The coercivity and remanence of roasted ores decreased with increasing roasting temperature.The scanning electron microscope(SEM) study showed that more cracks were produced by the reoxidation of reduced ores,which could possibly favor the intergranular fracturing and the liberation for further treatment.展开更多
文摘The activity model of CaO-FeO-SiO_2-MoO_3 quarternary system was establishedaccording to the coexistence theory of slag structure and the reduction thermodynamics of molybdenumoxide was discussed by applying this model. The activities of SiO_2 and MoO_3 decrease, while thatof CaO increases with increasing the basicity of slag. Among SiC, [C] and [Si] reactants, thereducing capability of SiC is the strongest, while that of [C] is the poorest at a high temperature(about 1873 K). It is advantageous to increase the yield of molybdenum by increasing the content of[Si] or [C]. Controlling of basicity of slag can prevent the oxidation loss of molybdenum.
文摘为了探究不同湿度铁矿石在计量斗内的黏附情况,采用Hertz-Mindlin with JKR模型,利用EDEM对不同湿度铁矿石在计量斗中的运动行为进行仿真分析,探讨不同含水率对铁矿石在计量斗壁面上的黏附影响。结果表明:含水铁矿石的落料速度远小于无水矿石,且随着含水率的增加,铁矿石在同一时刻的速度明显下降;经过堆料过程,矿石间及矿石与壁面间的粘结更加紧密,且随含水率的增加,F_(JKR1)与F_(JKR2)的值越大,黏附在壁面上的矿石质量越大。所作研究可为计量斗清堵装置的设计提供一定的理论帮助。
文摘Magnetizing roasting via a fluidized bed,which was recognized as an efficient method for beneficiation of low-grade iron ores,has attracted much attention in China recently due to the fluctuation of the international iron ore market.In order to examine the effects of magnetic properties on the separability and to optimize the operating parameters,magnetic susceptibility and coercivity of a low-grade hematite after magnetizing reduction and reoxidation under different conditions were investigated.It was found that the magnetic susceptibility of roasted ore increased with reduction degree and particle diameter to different degrees.The magnetite was re-oxidized to maghemite when the temperature was below 400℃,and the magnetic susceptibility decreased slightly.The recovery efficiency decreased notably with the particle size for very fine grains although no significant change was found in magnetic susceptibility.The coercivity and remanence of roasted ores decreased with increasing roasting temperature.The scanning electron microscope(SEM) study showed that more cracks were produced by the reoxidation of reduced ores,which could possibly favor the intergranular fracturing and the liberation for further treatment.
