【作者】 魏国兵；

【导师】 谢卫东；

【作者基本信息】 重庆大学 ， 材料学， 2010， 硕士

【摘要】 真空热还原制备技术具有生产工艺较简单、产品纯度高等优点,在有色金属冶金领域占有非常重要的位置。是冶炼和提纯镁、钙、锶、钡、锂、钠、钾等金属的常用方法。本论文针对现有的还原制备镁及镁合金技术总存在的还原时间长、温度高、资源能源利用率低、还原罐损耗大等问题,通过还原过程热力学及动力学分析及实验研究,探寻了影响还原反应速度和还原率的主要因素及其改良途径,提出了几种镁及镁合金高效热还原制备新方法。论文主要工作及结果包括:1.对真空热还原制备镁及镁合金的动力学分析表明,改善还原反应过程中的热量传输及质量传输过程是实现还原反应的快速、充分进行的关键,是发展热还原制镁及镁合金新方法的途径之一。2.在系统压强为100Pa、温度为1200℃时能实现Mg、Sr合金的同步还原与冷凝,证实了热还原法直接制备镁合金的理论可行性及实践可操作性。3.提出了微粉热还原镁及镁合金新方法。该方法通过细化反应物料至微纳米级,使反应物料产生明显的表面效应、微尺度效应,并提高催化剂性能,从而显著提高热量传输和质量传输效率,实现还原反应的快速充分进行。在解决物料微粉化磨制的技术性与经济性等问题后,可望实现对常规热还原制镁及镁合金技术的改良。4.提出了球磨/搅拌热还原制备镁及镁合金新方法。该方法通过在还原反应过程中球磨或(和)搅拌反应体系,从而大幅削弱渣相对反应物间的隔离作用,增加反应物料之间的接触几率,进而大幅提高热量传输、质量传输效率,实现还原反应的快速充分进行。在解决反应罐的密封等装备问题后,该方法可望发展成为一种能源、资源利用率高,综合技术经济效益好的热还原制镁及镁合金新方法。5.提出了固—液热还原制备镁及镁合金新方法。该方法通过采用液态还原剂,实现热还原反应环境由固—固态转变为固—液态,大幅度改善热量传输、质量传输条件。在解决还原罐内固液均匀混合实现方式等问题后,该方法可望发展成为一种能源、资源利用率高,综合技术经济效益好的热还原制镁及镁合金新方法。更多还原

【Abstract】 With such advantages as simple production engineering, high purity production, vacuum-thermal reduction technology takes a important position in non-ferrous metallurgy field. It is a common method used in smelting and refining such metals as magnesium, calcium, strontium, barium, lithium, sodium, potassium.This paper aimed at such problems as long reduction time, high temperature, low utilization rate of resources and energy, high loss of reduction tank at the reduction preparation of magnesium and magnesium alloy technology, through the reduction process thermodynamics and kinetics analysis also experimental study, exploring the main parameters effect on reaction speed , reduction rate and it’s improvement measures, proposed several new method of reduction preparation of magnesium and magnesium alloy.The main work and findings in this dissertation include:1. The dynamic analysis of the vacuum thermal reduction preparation of magnesium and magnesium alloys indicates that the process improvement of heat transfer and quality transfer during the reduction is the key to achieve rapid and fully reduction. It is also a method to develop new ways of thermal reduction preparation of magnesium and magnesium alloys.2. With the system pressure of 100Pa and temperature of 1200℃, Mg alloy and Sr alloy can be reduced and condensate simultaneously. Theoretical possibility and practice operability of thermal reduction preparation magnesium alloy are proved.3. A new method of macro-powder thermal reduction preparation of magnesium and magnesium alloys is proposed. In this method, reaction materials that were refined to micro-nano show significant surface effect and microscope effect, the catalyst performance was improved, lead to significantly development of the efficiency of heat transfer and mass transfer, achieve the rapid and fully reduction reaction. After solving the technical and economic problems of micronized milling of materials, this method is expected to improve the conventional thermal reduction preparation of magnesium and magnesium alloy technology.4. A new method of milling/stirring thermal reduction preparation of magnesium and magnesium alloys is proposed. In this method, the reaction system was milled or (and) the stirred during the reduction process, thus significantly weaken the separation between the reactants caused by residue and increase the probability of contact between reactants, and substantially increased the efficiency of heat transmission and quality transmission, achieved rapid and fully reduction. After solving such equip problem as the sealing of reaction tank, this method is expected to develop into a energy and resource- economic, Comprehensive technical economic efficiency new method for thermal reduction preparation of magnesium and magnesium alloys.5. A new method of solid - liquid thermal reduction preparation of magnesium and magnesium alloy is proposed. With the use of liquid reducing agent, the thermal reduction reaction environment change from solid - solid into solid - liquid, lead to significant improvement of heat and quality transfer. After the realization of mixing solid and liquid material uniformly in the reduction tank, this method is expected to develop into an energy and resource-efficient, comprehensive technical economic efficiency new method for thermal reduction preparation of magnesium and magnesium alloys.更多还原