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.pdfVIP

34 1 真 空 科 学 与 技 术 学 报 第 卷 第 期 60 CHINESE JOUＲNAL OF VACUUM SCIENCE AND TECHNOLOGY 2014 1 年 月 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 傅大学 王耀武 彭建平 狄跃忠 冯乃祥* ( 110819) 东北大学材料与冶金学院 沈阳 Improvements of Mg-Extraction from Magnesite and Dolomite by Aluminathermic Ｒeduction in Vacuum * Fu Daxue ，Wang Yaowu ，Peng Jianping ，Di Yuezhong ，Feng Naixiang (School of Materials and Metallurgy ，Northeastern University ，Shenyang 110819，China) Abstract The influence of the calcination conditions of dolomite and magnesite ，such as the powder size ，calci- nation temperature ，and pellet compression pressure ，on the pellet density and on the Mg reduction rate in Mg-extrac- tion by aluminathermic reduction in vacuum ，was studied． The microstructures 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 ，roasted at 750℃ and 1100℃ ， respectively ;and the highest Mg yield (0． 6626 g /cm3 )was obtained ，per unit volume ，at 750℃ and 1200℃ ，r