摘要
Given the considerable global interest in the preparation of Ti and TiC,a novel reduction method for TiO_(2) in a CH_(4)-H_(2) atmosphere was proposed,and the reduction thermodynamic behavior,phase equilibrium,and energy consumption of TiO_(2) during its reaction with a CH_(4)-H_(2) gas mixture were investigated.The results indicate that the reaction proceeds via a stepwise reduction pathway from TiO_(2) to Ti(C,O),with the Magnéli phase(TinO_(2n-1))and Ti_(3)O_(5) serving as intermediate phases.Notably,the reduction of TiO_(2) by H_(2) is more challenging than that by CH_(4),which may be attributed to the inhibitory effect of H_(2) on the surface carbon precipitation.For the complete carbonization of 1 mol TiO_(2),the total energy required at 1000,1100,and 1200℃is 1159,925,and 977 kJ/mol,respectively,which may be related to the shift of gas-phase equilibrium and the increase in side reactions at high temperatures.
针对钛及碳化钛制备这一全球关注的重要课题,开发了一种基于CH_(4)-H_(2)混合气体的新型TiO_(2)还原工艺,并对其中存在的热力学行为、相平衡和能耗进行了研究。结果表明,在CH_(4)-H_(2)混合气氛下,TiO_(2)的还原过程呈现出独特的逐步转化特征,其反应路径遵循从TiO_(2)到Ti(C,O)的演变规律,过程中可观察到Magnéli相(TinO_(2n-1))和Ti_(3)O_(5)等低价氧化物作为重要的中间相存在。与传统的纯CH_(4)还原体系相比,H_(2)的引入显著增加了反应难度,这一现象可能与H_(2)对表面碳沉积的抑制作用有关。在能量消耗方面,获得了具有重要指导意义的数据:在标准条件下,1000℃时完全碳化反应的能耗为1159 kJ/mol,当温度升至1100℃时能耗显著降低至925 kJ/mol,而继续升温至1200℃时却出现能耗回升至977 kJ/mol的反常现象,这可能与高温下气相平衡的移动和副反应增加有关。
出处
《稀有金属材料与工程》
北大核心
2026年第3期615-626,共12页
Rare Metal Materials and Engineering
