Yong Hou, Shuo Zhang, Jie Dang, Zhixiong You, Xuewei Lv
{"title":"Electrical Conductivity and Structure of CaO–MgO–SiO2–Al2O3–BaO Slag with Different BaO/Al2O3 Molar Ratios","authors":"Yong Hou, Shuo Zhang, Jie Dang, Zhixiong You, Xuewei Lv","doi":"10.1007/s11663-024-03172-5","DOIUrl":null,"url":null,"abstract":"<p>This study investigated the impact of BaO/Al<sub>2</sub>O<sub>3</sub> molar ratio on the electrical conductivity and Al coordination state of CaO–MgO–SiO<sub>2</sub>–Al<sub>2</sub>O<sub>3</sub>–BaO slag using four-electrode technique and <sup>27</sup>Al MAS-NMR spectroscopy, respectively. With an increasing BaO/Al<sub>2</sub>O<sub>3</sub> molar ratio from 0.14 to 0.36, BaO preferentially participated in charge compensation of Al<sup>3+</sup>, which facilitated the transition from AlO<sub>5</sub> and AlO<sub>6</sub> structures to AlO<sub>4</sub> structure and increased the stability of AlO<sub>4</sub> tetrahedra, thus enhancing the slag’s polymerization and reducing its electrical conductivity. However, once the compensation achieved equilibrium, remaining BaO was involved in depolymerizing the tetrahedral structure and promoting the formation of AlO<sub>5</sub> and AlO<sub>6</sub> structures. Consequently, the decreased degree of polymerization and increased concentration of free ions together led to an increase in electrical conductivity. However, the increased migration resistance due to the large radius of Ba<sup>2+</sup> ion is responsible for the electrical conductivity minimum near the molar ratio of 0.43.</p>","PeriodicalId":18613,"journal":{"name":"Metallurgical and Materials Transactions B","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Metallurgical and Materials Transactions B","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/s11663-024-03172-5","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
This study investigated the impact of BaO/Al2O3 molar ratio on the electrical conductivity and Al coordination state of CaO–MgO–SiO2–Al2O3–BaO slag using four-electrode technique and 27Al MAS-NMR spectroscopy, respectively. With an increasing BaO/Al2O3 molar ratio from 0.14 to 0.36, BaO preferentially participated in charge compensation of Al3+, which facilitated the transition from AlO5 and AlO6 structures to AlO4 structure and increased the stability of AlO4 tetrahedra, thus enhancing the slag’s polymerization and reducing its electrical conductivity. However, once the compensation achieved equilibrium, remaining BaO was involved in depolymerizing the tetrahedral structure and promoting the formation of AlO5 and AlO6 structures. Consequently, the decreased degree of polymerization and increased concentration of free ions together led to an increase in electrical conductivity. However, the increased migration resistance due to the large radius of Ba2+ ion is responsible for the electrical conductivity minimum near the molar ratio of 0.43.