Mechanism of lime decomposing Al_(2)O_(3)-containing fayalite melt  

石灰分解含Al_(2)O_(3)铁橄榄石熔体的机理

作　　者：Hui-chuan REN Xiao-bo MIN Yong KE Long-gong XIA Yun-yan WANG Cong PENG Yun LI Rong-he TAN Chuan-fu ZHANG 任慧川;闵小波;柯勇;夏隆巩;王云燕;彭聪;李云;谭荣和;张传福(中南大学冶金与环境学院,长沙410083;有色金属强化冶金新技术全国重点实验室,长沙410083;国家重金属污染防治工程技术研究中心,长沙410083;长沙有色冶金设计研究院有限公司,长沙410001)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals,Changsha 410083,China [3]Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution,Changsha 410083,China [4]CINF Engineering Corporation Limited,Changsha 410001,China

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第11期3707-3720,共14页中国有色金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No.52121004);the National Science Fund for Distinguished Young Scholars (No.51825403);the Science and Technology Innovation Program of Hunan Province,China (No.2021RC3013);National Key R&D Program of China (No.2022YFC3901602);the Major Science and Technology Project of Gansu Province,China (No.21ZD4GD033)。

摘　　要：A method to upgrade the iron grade in copper slag was proposed using lime to decompose Al_(2)O_(3)-containing fayalite melt(AFMT).Thermodynamic calculations indicated that adjusting the CaO/AFMT ratio can yield a residual melt with a FeO concentration of 75−88 wt.%and produce Ca_(2)SiO_(4).In-situ observations suggested that the reaction was impeded in some way.Quenching experiments revealed that the initial reaction products consisted of calcium ferrite compounds and FeO−CaO melt.At the FeO−CaO melt/AFMT interface,Ca_(2)SiO_(4) particles precipitated,forming a dense Ca_(2)SiO_(4) film that significantly impeded mass transfer.Although trace amounts of Al_(2)O_(3) in AFMT temporarily enhanced mass transfer,they were insufficient to overcome this retardation effect.The decomposition reaction was far from achieving equilibrium,demonstrating a self-retardation effect.Measures must be implemented to eliminate this self-retardation effect and enhance the efficiency of reaction kinetics.提出利用石灰分解含Al_(2)O_(3)铁橄榄石熔体(AFMT)提高铜渣中铁品位的方法。热力学计算表明,调整CaO/AFMT的比例,可生成FeO质量分数为75%~88%的残余熔体和Ca_(2)SiO_(4)。原位观察表明,该反应受到某种阻碍。淬火实验表明,反应的初始产物为钙铁酸盐化合物和FeO-CaO熔体。在FeO-CaO熔体/AFMT界面,Ca_(2)SiO_(4)颗粒沉淀,形成一层致密的Ca_(2)SiO_(4)膜,严重阻碍了传质。虽然AFMT中微量的Al_(2)O_(3)暂时促进了传质,但不足以克服这种阻滞效应。分解反应远未达到平衡,表现出一种自阻滞效应。应采取措施消除这种自阻滞效应,提高反应动力学效率。

关 键 词：LIME Al_(2)O_(3)-containing fayalite melt Ca_(2)SiO_(4)film self-retardation mass transfer 

分 类 号：X758[环境科学与工程—环境工程]