富稀土高炉渣含铝压块在纯铁中直接合金化行为研究  

Study on Direct Alloying to Pure Iron by Rare Earth-rich Aluminum-containing Blast Furnace Slag Briquetting

作　　者：瞿伟 任慧平 刘玉宝[3] 董方[1] 金自力 王彦儒 QU Wei;REN Hui-ping;LIU Yu-bao;DONG Fang;JIN Zi-li;WANG Yan-ru(Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources,Baotou 014010,China;School of Materials Science and Engineering^Shanghai University,Shanghai 200072,China;Baotou Research Institute of Rare Earths,Baotou 014030,China)

机构地区：[1]内蒙古自治区白云鄂博矿多金属资源综合利用省部共建国家重点实验室培育基地,内蒙古包头014010 [2]上海大学材料科学与工程学院,上海200072 [3]包头稀土研究院,内蒙古包头014030

出　　处：《稀土》2020年第3期53-59,共7页Chinese Rare Earths

基　　金：国家自然科学基金项目(51261018);内蒙古科技大学创新基金项目(2017QDL-S02)。

摘　　要：研究了富稀土元素高炉渣含铝压块中稀土直接合金化行为。在氩气保护的高温管式炉中将含铝高炉渣压块在1550℃保温1 h,采用X射线衍射仪和场发射电子显微镜中的能谱扫描及电子背散射衍射(EBSD)技术分析铝热还原的微观过程。利用30 kg级中频感应炉冶炼10 kg纯铁,待铁水熔化后加入100 g高炉渣和40 g铝粉压成的自还原块进行稀土元素直接合金化,分别在不同时间取样,利用电感耦合等离子体质谱仪检测铁水样中的镧和铈的含量。结果表明,铝热还原富稀土高炉渣中稀土元素的微观过程有三个阶段:首先是铝热还原硅元素的过程,SiO2→Al9Si→Si;然后是硅热还原钙元素的过程,CaO→CaSi2;最后是CaSi2还原稀土元素的过程,CaSi2→(Ca0.8RE0.2)Si2。铁水中镧和铈的含量随时间变化都是先增加,后略有下降并趋于平缓,最终冷却至室温的铁块中镧和铈的含量为1.5×10^-6和2.78×10^-6,还原率分别为11.73%和8.76%。Direct alloying to pure iron by rare earth-rich aluminum-containing blast furnace slag briquetting has been studued.The rare earth-rich aluminum-containing blast furnace slag briquetting was heat treated at 1550℃in a tube furnace for 1 hour,and then the micro process of the aluminothermic reduction was analyzed by X-ray diffraction,energy disperse spectroscopy(EDS)scanning and electron back scattering diffraction(EBSD)of field emission scanning electron microscopy(FE-SEM).100 g blast furnace slag and 40 g aluminite powder were mixed and briquetted to briquettings which were added into 10 kg molten pure iron in 30 kg grade medium-frequency induction furnace for rare earth direct alloying.The specimens were extracted at different time and the lanthanum and cerium contents in the iron specimens were detected by inductively coupled plasma source mass spectrometer(ICP-MS).The results indicate that,there were three steps during the micro process of the aluminothermic reduction:firstly,silicon oxide was reduced by the aluminum,SiO2→Al9Si→Si.Then,calcium oxide was reduced by the silicon,CaO→CaSi2.At last,rare earth oxides were reduced by the CaSi2,CaSi2→(Ca0.8RE0.2)Si2.The lanthanum and cerium contents in the molten iron climbed up,then declined slightly and tended to be gentle.The lanthanum and cerium contents in the iron which was cooled to room temperature were 1.5×10^-6 and 2.78×10^-6.In addition,the reduction ratios of lanthanum and cerium were 11.73%and 8.76%,respectively.

关 键 词：稀土元素 高炉渣 铝热还原 微观过程 直接合金化 

分 类 号：TF633[冶金工程—钢铁冶金]