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采用热重分析法研究了H2-CO还原钛精粉的特征。热重、相组成和形貌分析表明:在纯H2基础上,配加CO还原钛精粉的热重曲线具有相似性,即质量分数首先随时间的延长而下降,达到平衡后维持一定时间,随后逐渐增加;在质量分数降低的过程中,失重率随H2含量的增加而增加;相反,在质量分数增加的过程中,增重率首先随CO含量的减小而增加,至80%CO时达到最大值,而后逐渐减小。要保证还原产物中铁元素主要以金属相、非渗碳体相形式存在的合理温度是1150℃;开始阶段由于氢气原子半径小、扩散能力强,H2含量高时,产物表面孔隙较多,利于气体传输,还原能力强,随后由于渗碳体参与还原反应,产生大量气体,产物破碎程度增强,增加了其比表面积。
The characteristics of H2-CO reduced titanium powder were studied by thermogravimetric analysis. The results of thermogravimetry, phase composition and morphology show that the thermogravimetric curves of pure titanium dioxide with CO reduction of titanium powder have similarities, that is, the mass fraction first decreases with time, reaches the equilibrium state and maintains for a certain period of time, Then gradually increased. In the course of decreasing the mass fraction, the weight loss rate increased with the increase of H2 content. On the contrary, the weight gain rate increased with the decrease of CO content in the process of mass fraction increasing. At 80% CO Reach the maximum, then decrease gradually. To ensure that the reduction of iron is mainly metal phase, non-cementite phase exists in the form of a reasonable temperature is 1150 ℃; the beginning of the hydrogen atom due to a small radius, strong diffusion ability, H2 content is high, the product surface porosity is more conducive to the gas Transmission and reduction ability, and then due to cementite involved in the reduction reaction, resulting in a large number of gases, the degree of product crushing increased, increasing its specific surface area.