Analysis of dominant phases inhibiting dissociation of smelting slags and the alkali depolymerization mechanism  

作　　者：Juan-Li Yuan Jing-Biao Liu Zhen Wu Xiang-Ying Lv Jian-Wei Du Xue-Ming Liu Hong Deng Zhang Lin 

机构地区：[1]School of Environment and Energy,Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Resource Recycling,South China University of Technology,Guangzhou 510006,China [2]School of Advanced Manufacturing School of Ocean,Fuzhou University,Quanzhou362251,China [3]School of Chemistry and Chemical Engineering,Shandong University,Jinan250100,China [4]South China Institute of Environmental Science,Ministry of EcologyandEnvironment,Guangzhou510535,China [5]College of Metallurgy and Environment,Central South University,Changsha 410083,China

出　　处：《Rare Metals》2024年第11期6068-6080,共13页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.22006040 and 22376070);the National Key Research and Development Program of China(No.2019YFA0210404);the Research Project on Characteristic Innovation of University Teachers(No.2022XJZZ02)。

摘　　要：This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for the resource utilization of smelting slag.An intricate correlation between metallic elements and dominant phases was constructed.Typical silicate phase olivine(OL)was synthesized as a paradigm to examine alkali depolymerization,unveiling the optimal conditions for such depolymerization to be an alkali to olivine molar ratio of 1:5,a reaction temperature of 700℃,and a duration of 3 h.The underlying mechanism of alkali depolymerization within silicate phases was elucidated under these parameters.The reaction mechanism of alkali depolymerization within silicate phases can be encapsulated in three sequential steps:(1)NaOH dissociation and subsequent adsorption of OH^(-)to cationic(Mg or Fe)sites;(2)disruption of cation-oxygen bonds,leading to the formation of hydroxide compounds,which then underwent oxidation;(3)Na^(+)occupied the resultant cation vacancy sites,instigating further depolymerization of the intermediate Na_(2)(Mg,Fe)SiO_(4).The articulated mechanism is anticipated to furnish theoretical underpinnings for the efficacious recuperation of metals from smelting slags.

关 键 词：Smelting slag Key phase analysis Silicate phases Alkali depolymerization mechanism 

分 类 号：X756[环境科学与工程—环境工程] TF803[冶金工程—有色金属冶金]