Formation mechanism of bonded slag pellets in vertical-pot Pidgeon process of magnesium production  

竖罐皮江法炼镁黏结渣球的形成机理

作　　者：Ji-lei XU Jin-hui LIU Yu-ming ZHAO Zhi-ping MAO Wei-neng TANG Xiao-feng LI Pei-xu YANG Wei-dong ZHANG Shao-jun ZHANG 许记雷;刘金辉;赵玉明;毛志平;唐伟能;李晓峰;杨沛胥;张伟东;张少军(郑州大学材料科学与工程学院,郑州450001;河南工程学院材料工程学院,郑州451191;中国宝武钢铁集团公司宝钢金属股份有限公司,上海200940)

机构地区：[1]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China [2]College of Materials Engineering,Henan University of Engineering,Zhengzhou 451191,China [3]Baosteel Metal Co.,Ltd.,China Baowu Steel Group Corporation,Shanghai 200940,China

出　　处：《Transactions of Nonferrous Metals Society of China》2025年第2期625-639,共15页中国有色金属学报(英文版)

基　　金：China Postdoctoral Science Foundation (No. 2020M682337)。

摘　　要：In the Pidgeon process involving a vertical pot,bonded slag pellets occasionally emerge at the bottom of the reduction pot,impeding smooth slag discharge.To reveal the formation mechanism of the bonded slag pellets,thermodynamic calculations,X-ray diffraction(XRD),X-ray fluorescence spectrometry(XRF),electron probe microanalyzer(EPMA),X-ray photoelectron spectroscopy(XPS),and differential scanning calorimetry(DSC)were employed.The bonded slag pellets mainly comprise MgO,CaSi_(2),CaO,and Ca2SiO_(4).CaSi_(2) in the bonded slag pellets is attributed to the reduction reaction between Si and CaO,yielding liquid CaSi_(2).Simultaneously,the reaction between CaSi_(2) and MgO,which will typically produce Mg vapor,is inhibited,resulting in the accumulation of CaSi_(2).Owing to the solid-liquid transition of CaSi_(2),this process culminates in the bonding of slag pellets.This study can guide the Pidgeon process optimization,enabling mitigation of the“dead pot”issue,thereby enhancing efficiency and reducing costs.竖罐皮江法还原罐底部偶尔会出现黏结渣球的现象,导致无法顺利排渣。利用热力学计算、X射线衍射(XRD)、X射线荧光光谱(XRF)、电子探针显微分析仪(EPMA)、X射线光电子能谱(XPS)和差示扫描量热法(DSC)研究了黏结渣球的形成机理。黏结渣球的主要成分是MgO、Cai_(2)、CaO和CaO_(2)SiO_(4)。黏结渣球中存在Cai_(2)是由于Si还原CaO生成了液态Cai_(2)。同时,Cai_(2)和MgO之间产生Mg蒸气的反应被抑制,导致Cai_(2)在料球中积累。由于Cai_(2)的固液转变,这一过程最终导致渣球之间黏结。这项研究可以指导皮江法工艺优化,缓解“死罐”问题,从而提高效率并降低成本。

关 键 词：vertical-pot Pidgeon process slag discharge bonded slag pellets CaSi_(2) solid−liquid transition 

分 类 号：TF822[冶金工程—有色金属冶金]