菱镁石和白云石的煅烧条件对球团密度及还原过程的影响  

Improvements of Mg-Extraction from Magnesite and Dolomite by Aluminathermic Reduction in Vacuum

作　　者：傅大学[1] 王耀武[1] 彭建平[1] 狄跃忠[1] 冯乃祥[1] 

机构地区：[1]东北大学材料与冶金学院,沈阳110819

出　　处：《真空科学与技术学报》2014年第1期60-67,共8页Chinese Journal of Vacuum Science and Technology

基　　金：辽宁省镁质材料行业高新技术研发项目(MYF2011-34);中央高校基本科研业务费资助项目(N100302009);辽宁省工业攻关项目(2011221002)

摘　　要：研究了白云石和菱镁石的煅烧条件对获得的熟料压制成球团的密度的影响,并以菱镁石和白云石的混合物为原料,铝粉为还原剂考察了煅烧条件对还原过程的影响。实验结果表明:随着菱镁石和白云石煅烧温度的提高,球团的密度增加。在煅烧过程中,假晶的形成和破坏是导致球团密度变化的主要原因。在750和1100℃煅烧的菱镁石和白云石,单位质量原料产镁最多,为0.3143;在750和1200℃煅烧的菱镁石和白云石,单位体积原料可以产出更多的镁,达到0.6626 g/cm3。综合考虑成本因素,认为菱镁石和白云石的最佳煅烧温度分别为750和1100℃。The influence of the calcination conditions of dolomite and magnesite, such as the powder size,calcination temperature,and pellet compression pressure,on the pellet density and on the Mg reduction rate in Mg-extraction by alu- minathermic reduction in vacuum, was studied. The micmstructures of the pellets were characterized with scanning electron microscopy. The results show that the calcination temperature strongly affects the pellet density and Mg reduction rate, possibly because of the formation and destruction of the pseudomorphs during the decomposition of magnesite and dolomite. For example, the pellet density increased with an increase of the calcination temperatures. The maximum Mg yield （0.3143） was obtained, per unit mass of magnesite and dolomite, masted at 750℃ and 1100℃, respectively; and the highest Mg yield （0.6626 g/cm3）was obtained, per unit volume, at 750℃ and 1200℃, respectively. When production cost is considered, the compromised calcination conditions include the roast-temperature of 750℃ for magnesite and 1100℃ for dolomite.

关 键 词：菱镁石 白云石 煅烧条件 假晶 

分 类 号：TB822[一般工业技术—摄影技术]