肯尼亚天然金红石矿沸腾氯化热力学和动力学(英文)

Fluidized-bed chlorination thermodynamics and kinetics of Kenya natural rutile ore

以焦炭作还原剂,利用天然金红石和氯气制备四氯化钛。在1173到1273 K的温度范围内,对肯尼亚天然金红石颗粒在间歇式流化床中的氯化反应热力学和动力学进行研究。体系的热力学分析显示:生成CO的反应在高温下占主导地位;若生成CO反应的比率η越大,且随着体系反应受温度的影响加剧,高温下反应的吉布斯自由能越负;同时,η增大,产物中TiCl4分压对反应的吉布斯自由能的影响趋于减小。应用气-固多相反应理论和流化床两相模型建立反应的数学模型,计算了气泡相和乳相中模型的各种参数,床层高度范围内氯气的平均浓度为0.3 mol/m3。结果表明:天然金红石氯化反应主要在乳相中进行,反应速率主要由界面反应控制。

Natural rutile and gaseous chlorine with carbon as reductant were used to prepare titanium tetrachloride. Thermodynamics and kinetics of chlorination of Kenya natural rutile particles in a batch-type fluidized bed were studied at 1173-1273 K. Thermodynamic analysis of this system revealed that the equation of producing CO was dominant at high temperatures. Based on the gas-solid multi-phase reaction theory and a two-phase model for the fluidized bed, the mathematical description for the chlorination reaction of rutile was proposed. The reaction parameters and the average concentration of gaseous chlorine in the emulsion phase were estimated. The average concentration of emulsion phase in the range of fluidized bed was calculated as 0.3 mol/m^3. The results showed that the chlorination of natural rutile proceeded principally in the emulsion phase, and the reaction rate was mainly controlled by the surface reaction.