多级深度还原法直接制备钛粉  

Direct Preparation of Titanium Powder by Multistage Deep Reduction

作　　者：范世钢 豆志河[1] 张廷安[1] 张博文[1] 牛丽萍[1] Fan Shigang;Dou Zhihe;Zhang Ting'an;Zhang Bowen;Niu Liping(Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学多金属共生矿生态化冶金教育部重点实验室,辽宁沈阳110819

出　　处：《稀有金属材料与工程》2020年第3期1020-1023,共4页Rare Metal Materials and Engineering

基　　金：重点基础研发计划(2017YFB0305401-2);中央直属高校基本科研业务费(N172506009,N170908001)。

摘　　要：针对传统钙、镁等金属热还原TiO2制备金属钛粉过程存在的效率低、脱氧不彻底的技术瓶颈,基于TiO2分步还原的热力学平衡特点,结合镁钙电负性差异,提出了多级深度还原法直接制备钛单质的工艺:即TiO2先镁热自蔓延一次还原得到一次还原产物,然后将一次还原产物进行钙热深度还原制备还原钛粉。采用对比研究法,考察了TiO2镁热还原和钙热还原的热力学及动力学差异;考察了镁热一次还原过程中TiO2机制与还原程度,以及一次还原产物不同深度还原模式下脱氧机制。结果表明:一次还原产物先酸浸预除杂,然后进行钙热深度还原更利于彻底脱氧,最终制备出氧含量仅为0.21%(质量分数),纯度>99.0%可以商用的钛粉。There is a technical bottleneck in the preparation of metallic titanium powder by conventional thermal reduction of TiO2 with calcium, magnesium, or other metals, such as low efficiency and incomplete deoxidation. Based on the thermodynamic equilibrium characteristics of the step-by-step reduction of TiO2, a comparative study method was used, and the thermodynamic and kinetic differences between magnesia and calcium heat reduction of TiO2 were investigated in this paper. Considering the difference in the electronegativity between magnesium and calcium, a new idea was put forward that the primary reduction product is prepared by a primary reduction process of TiO2 in the form of magnesiothermic self-propagation high-temperature synthesis(SHS), and then the reduced titanium powder is obtained by the primary reduction product for a deep calcium-thermal reduction reaction. The reduction degree and mechanism of TiO2 during the primary magnesium thermal reaction and deoxidation mechanism of primary reduction products in different deep reduction modes were also investigated. The results show that it is more conducive to undergo complete deoxygenation such that the primary reduction product is first acid-impregnated followed by deep calciothermic reduction. High purity reduced titanium powder with a final oxygen content of only 0.21% and purity greater than 99.0% is obtained.

关 键 词：多级深度还原 钛粉 二氧化钛还原 

分 类 号：TG146.23[一般工业技术—材料科学与工程]