摘要
针对高钙镁钛精矿难以满足沸腾氯化制备四氯化钛工艺问题,从热力学和动力学角度对高钙镁钛原料碳热还原—沸腾氯化制备TiCl_(4)工艺进行了深入研究。结果表明:钛精矿高温碳热还原历程为:FeTiO_(3)→TiO_(2)+Fe→Ti_(n)O_(2) n-1(n=4~9)+Fe→Ti_(3)O_(5)+Fe→Ti_(2)O_(3)+Fe→TiC_(x)O_(1-x)+Fe,碳氧钛生成的温度必须高于1400℃,此时钛精矿中的Ca、Mg、Al、Si、Mn等杂质元素在1800℃以内都不会被还原为对应的碳化物;高钙镁钛铁矿精矿碳热还原制备碳氧钛过程中,失重率随温度升高呈现4阶段上升,其中阶段1和3分别为受扩散控制生成金属Fe和碳氧钛的快速失重段,而阶段2和4分别为金属Fe和碳氧钛形核长大的缓慢失重阶段,4个阶段的表观活化能分别为49.84、-2.24、12.82、-2.53 kJ mol。沸腾氯化过程还原产物中的Fe、MgO和CaO均会优先被氯气氯化,但当存在TiO_(2)时,SiO_(2)和Al_(2)O_(3)则不易被氯化,碳氧钛较适宜沸腾氯化的温度为300~650℃,沸腾氯化前5分钟为还原产物中碳氧钛的快速氯化阶段,主要受表面化学反应的控制,而后5~20分钟为Ti_(2)O_(3)的缓慢氯化阶段,主要受颗粒内部扩散控制的影响。
Aiming at the problems that high Ca and Mg impurities ilmenite concentrate is difficult to meet the boiling chlorination process for preparing TiCl_(4),the preparation of TiCl_(4) from high Ca and Mg titanium raw material by carbothermic reduction-boiling chlorination was systematic studied from the perspective of thermodynamics and kinetics.The results show that the high-temperature carbon thermal reduction process of ilmenite concentrate involved the stepwise reduction process:FeTiO_(3)→TiO_(2)+Fe→Tin O_(2) n-1(n=4-9)+Fe→Ti_(3)O_(5)+Fe→Ti_(2) O_(3)+Fe→TiC _(x)O_(1-x)+Fe.The temperature of carbon oxide titanium generation must be higher than 1400℃.However,the impurity elements such as Ca,Mg,Al,Si,Mn in titanium concentrate will not be reduced to corresponding carbides within 1800℃.In the process of carbothermic reduction of high Ca and Mg impurities ilmenite concentrate to prepare titanium oxycarbide,the weight loss rate increases in four stages with the increase of temperature.Among them,Stage 1 and Stage 3 are the rapid weight loss stages of metal Fe and carboxy-titanium controlled by diffusion,while Stage 2 and Stage 4 are the slow weight loss stages of metal Fe and carboxy-titanium nucleation and growth,respectively.The apparent activation energies of the four stages are 49.84,-2.24,12.82,and-2.53 kJ mol,respectively.During the boiling chlorination process,Fe,MgO,and CaO in the reduction products are preferentially chlorinated by chlorine gas,but when TiO_(2) is present,SiO_(2) and Al_(2)O_(3) are not easily chlorinated.The most suitable temperature for boiling chlorination is 300—650℃.The first 5 min of boiling chlorination is the rapid chlorination stage of titanium oxycarbide in the reduction products,which is mainly controlled by the surface chemical reaction,and the next 5 to 20 min is the slow chlorination stage of Ti_(2)O_(3),which is mainly affected by the internal diffusion control of the particles.
作者
朱福兴
马占山
陈爱祥
李良
黄志鹏
彭卫星
ZHU Fuxing;MA Zhanshan;CHEN Aixiang;LI Liang;HUANG Zhipeng;PENG Weixing(State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,Pangang Group Research Institute Co.,Ltd.,Panzhihua 617000,Sichuan,China;Panzhihua Titanium Material Co.,Ltd.,Pangang Group,Panzhihua 617000,Sichuan,China)
出处
《有色金属（冶炼部分）》
CAS
北大核心
2024年第6期42-52,共11页
Nonferrous Metals（Extractive Metallurgy)
基金
四川省科技计划项目(2019YJ0687)。
关键词
高钙镁钛精矿
沸腾氯化
四氯化钛
碳氧钛
high Ca and Mg impurities titanium concentrate
boiling chlorination
TiCl_(4)
titanium oxycarbide
