一步法制备镁钙合金的冷凝实验研究

One-Step Extraction of Mg-Ca Alloy from Dolomite & Magnesite Ores by Vacuum Aluminothermic Reduction

对以一步法制备镁钙合金实验中,在真空条件下,不同结晶器和不同结晶高度对金属蒸气冷凝的影响进行实验研究,并对金属产物及实验过程中的温度、压强进行分析。结果表明,当选用柱状结晶器且升华源与冷凝结晶器之间的距离为16.4cm进行实验时,收集到的金属块较厚、形状规则且冷凝结晶状态较好,此时有利于金属的收集,金属钙的分布从靠近结晶器到远离结晶器逐渐增多。本实验得到的金属产物可用作冶金工业复合脱氧剂及作为母合金生产其他合金。

A novel technique was developed to directly extract Mg-Ca alloy from calcined dolomite and magnesite ores by aluminothermic reduction in vacuum with Al-scraps as reductant.Conical-drum and solid T-cylinder crystallizer/condenser were used.The influence of the condensation conditions,including the reduction temperature,pressure,shape and bottom-height of condenser above sublimation surface,on the depth profiles of Mg and Ca in condensate was investigated with X-ray diffraction scanning electron microscopy and energy dispersive spectroscopy.The results show that at optimized reduction temperature,the height and geometry of condenser had a major impact.For example,when it comes to crystallization of Mg/Ca at optimized height of 16.4 cm,T-cylinder condenser outperformed conical-drum condenser with a descending sequence:Mg>Ca>CaO>CaMg2.The bottom-up depth profile of Mg decreased and that of Ca increased.The Mg-Ca alloy can be de-oxidizer and/or raw material in metal industry.