二段铝热制取钛粉/钛铝合金粉的基础研究

For its great strategic value and status in the national economy, titanium will become the third metal after iron and aluminum. At present，most of titanium metal in the world is produced by Kroll process, but Kroll process is a kind of heavy energy consumption, high cost and heavy pollution metallurgical industry which restrict the development of titanium industry seriously. A new method using sodium fluotitanate as materials and using aluminum as reductant has been invented. This method can significantly improve the utilization ratio of reductant and reduce energy consumption. So the process using aluminum as reductant is a very promising titanium production technology. In the project, the influence mechanism of reduction and distillation conditions on the reduction ratio of titanium and microstructure of titanium and Ti-Al alloy would be studied. The reaction mechanism of reduction process and formation mechanism of low-valent titanium would be investigated according to reduction thermodynamic and kinetics analysis. The reduction behavior and equilibrium mass distribution of oxide and fluoride in reduction and distillation process would be studied. The basis theory system of extracting titanium by vacuum thermal reduction using aluminum as reductant would initially establish through this project which provides theoretical basis and technical support for improving the reduction process of titanium production.

由于钛的重大战略价值和在国民经济中的地位，钛将成为继铁、铝之后崛起的“第三金属”。 Kroll法是目前工业上唯一生产金属钛的方法，但其工艺流程长、成本高、还原效率低，已严重制约了钛工业的发展。本课题组在铝热还原氟钛酸盐制取金属钛的基础上研发了一种两段铝热还原氟钛酸钠制取金属钛和钛铝合金的方法。本项目通过系统研究还原工艺技术条件对还原过程钛还原率和产物钛/钛铝合金微观结构的影响，借助于还原反应热力学和动力学分析，结合还原过程中的低价钛生成机理研究，阐明铝热还原氟钛酸钠制取钛/钛铝合金的还原机理，同时通过对杂质氧在还原过程中的还原反应行为及走向分析，结合钛/钛铝合金与氟化物蒸馏分离过程和产物钛/钛铝合金中杂质F分布研究，建立低成本铝热还原氟钛酸钠制取高质量钛/钛铝合金的基础理论体系，为该工艺的进一步改进与应用提供技术及理论指导。

Kroll法是目前世界上唯一大规模生产金属钛的方法，但该方法存在工艺过程复杂，能耗大，成本高，环境污染严重等问题，已严重制约了钛工业的发展。本项目对一种两段铝热还原氟钛酸钠制取金属钛和钛合金的工艺进行了研究。项目通过系统研究还原工艺技术条件对还原过程钛回收率和产物钛/钛铝合金微观结构的影响，结合还原过程中的低价钛生成机理研究，阐明了铝热还原氟钛酸钠制取钛/钛铝合金的还原机理，明晰了一段铝热还原过程中钛的损失机理，优化了还原工艺，建立了钛/钛铝合金的调控机制，实现了一段铝热还原副产物的回收再利用。通过对还原物料与产物中氧和氮的存在形式进行分析，明晰了还原产物中主要杂质氧氮的来源，并探讨了降低氧氮含量的措施，制备了氧含量低于0.4%，氮含量低于0.02%的钛/钛合金产品，初步建立了低成本铝热还原氟钛酸钠制取钛/钛合金的基础理论体系，为该工艺的工业化提供了理论指导。