采用化学分析、SEM、XRD分析了天然金红石的矿物组成,并对其微观结构进行了表征,采用单因素实验考察了氯化过程参数对其沸腾氯化反应活性的影响.结果表明,天然金红石的表面结构致密,沸腾氯化适宜的工艺参数为反应温度950℃、天然金红石粒径96μm、煅后石油焦粒径150μm、配碳比30:100、入口氯气流量0.036m3/h、氯化时间40min、入口氯气压力0.14MPa、氯气浓度100%.其氯化率可达95%以上.天然金红石与高钛渣的对比实验表明,钙、镁是影响氯化反应进行和最终氯化率的关键元素.天然金红石沸腾氯化过程动力学研究表明,该过程满足无固体产物层的收缩未反应核模型,在900~1000℃范围内,反应的活化能为9.17kJ/mol,反应受扩散过程控制,因此,增强传质、扩大有效反应面积是提高反应活性的有效途径.
Taking natural rutile as the research object,its mineral composition and microstructure are analyzed by chemical analysis,SEM,XRD,etc.,and the influences of process parameters on boiling chlorination reaction activity of natural rutile is studied by single-factor experiments. The results show that the surface structure of natural rutile is dense;appropriate process parameters of boiling chlorination process are: temperature 950℃,particle size of natural rutile-96 μm,particle size of calcined petroleum coke-150 μm,petroleum coke 30%,chlorine flow rate 0.036 m3/h,reaction time 30 min,gas pressure 0.14 MPa,concentration of chlorine 100%. In such conditions,the chlorination rate of natural rutile can reach over 95%. Contrast experiments of natural rutile and high-titanium slag shows that calcium and magnesium are the key elements of chlorination reaction and final chlorination rate. The research on boiling chlorination kinetics of natural rutile indicates that the process meets the contracting unreduced nucleus model without solid products. When the temperature range is from 900℃ to 1000℃,the activation energy is 9.17 kJ/mol. The reaction is controlled by diffusion. So the effective way to improve the reaction efficiency is intensifying the mass transfer and enlarging the effective reaction surface.