低氧化铝浓度下铝电解质的结构变化模拟研究  

Simulation study investigating the structural changes of aluminum electrolytes under low alumina concentration

作　　者：杜善周 黄涌波 刘瑞平[2] 张红亮 Du Shanzhou;Huang Yongbo;Liu Ruiping;Zhang Hongliang(Shenhua Zhungeer Energy Co.,Ltd.,Ordos 010300,China;Haerwusu Branch of China Shenhua Energy Co.,Ltd.,Ordos 010300,China;School of Metallurgy and Environment,Central South University,Changsha 410083,China)

机构地区：[1]神华准格尔能源有限责任公司,内蒙古鄂尔多斯市010300 [2]中国神华能源股份有限公司哈尔乌素分公司,内蒙古鄂尔多斯市010300 [3]中南大学冶金与环境学院,湖南长沙410083

出　　处：《轻金属》2023年第9期17-23,共7页Light Metals

基　　金：国家重点研发计划项目(2022YFB3304902);国家自科基金联合基金(U2202253);云南省重大科技专项计划项目(202202AB080017);国家自科基金重点基金(62133016,51974373);国家能源投资集团有限公司科研项目(GNJT-21-160);中南大学2023年度前沿交叉项目(2023QYJC007)。

摘　　要：电解铝生产过程的电解效率和有害气体排放量与氧化铝浓度密切相关。低氧化铝浓度下,阳极效应的发生会导致全氟化碳等环境有害气体的排放。因此,研究低氧化铝浓度下电解质中络合离子的种类和数量,对生产实践中的氧化铝浓度控制和参数调节进行分子层面的理论性指导是必要的。本文采用第一性原理分子动力学计算方法结合树状结构递归搜索算法,针对铝电解过程中低氧化铝浓度电解质中O、F元素在溶解态形态不明的问题,利用第一性原理分子动力学方法计算了熔盐体系微观离子结构。计算结果表明,F离子大部分以端氟F_(t)(Al-F)形式存在,而O离子全部以桥氧O_(b)(Al-O-Al)形式存在。络合离子以[AlF_(5)]^(2-)和大型铝氧氟配离子为主。The electrolysis efficiency and harmful gas emissions in the production of aluminum are closely linked to the concentration of alumina.At low alumina concentrations,the occurent of anode effects could lead to the emission of environmentally-hazardous gases such as perfluorocarbons(PFCs).Therefore,a molecular-level theoretical approach to investigating the types and quantities of complex ions in the electrolyte at low alumina concentrations is necessary to guide alumina concentration control and production parameter adjustment.In this study,we employed a first-principles molecular dynamics simulation in conjunction with a tree-based recursive search algorithm to address the issue of unclear forms of O and F elements in the molten salt during aluminum electrolysis with low alumina concentration.We calculated the microscopic ion structure of the molten salt system with first-principles molecular dynamics and found that F ions mainly exist as end-fluorine F t(Al-F),while O ions exist entirely in the form of bridging oxygen O b(Al-O-Al).Complex ions are dominated by[AlF 5]2-and large aluminum-oxygen-fluoride complexes.

关 键 词：电解铝 电解质 第一性原理分子动力学计算 熔盐结构 

分 类 号：TF821[冶金工程—有色金属冶金]