活性炭碳热还原钛铁矿的动力学研究

摘要

研究氩气气氛下,钛铁矿与不同质量分数的活性炭在1373～1773 K温度区间内的等温碳热还原反应.通过红外气体分析仪得到了碳热还原过程中的动力学曲线.研究结果表明,除1473 K外,在其他反应温度下改变活性碳的添加量几乎不影响反应速率.当反应温度高于Fe-C二元系共晶温度1427 K时,部分碳会溶解在铁中形成液相.此时,碳能通过液态铁传输扩散到反应界面.当反应温度高于1573 K时,碳热还原钛铁矿符合收缩核模型.还原产物中碳化钛的质量分数可以通过标准添加法测量.%The carbothermic reduction of Panzhihua ilmenite with various additions of activated carbon was investigated by isothermal experiments over the temperature range of 1373 to 1773 K in the argon atmosphere.According to the reaction kinetics recorded by the infrared gas analyzer,it was found that the amount of carbon addition had little influence on the reaction rates at various temperatures except 1473 K.When the reaction temperature was above the eutectic temperature of 1427 K of Fe-C binary system,part of carbon would dissolve into Fe to form a liquid phase,which made the liquid Fe as a diffusion channel of carbon to diffuse to the reaction interface.The carbothermic reduction above 1573 K obeyed the shrinking-core model.The mass fraction of TiC could be determined by the standard addition technique.