Basic Research On New Method Of High Efficiency Thermal Reducing Preparation Of Mg And Mg Alloys

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.