Lithium and manganese extraction from manganese-rich slag originated from pyrometallurgy of spent lithium-ion battery

废旧锂离子电池火法冶炼富锰渣中锰和锂的提取

Mn and Li were selectively extracted from the manganese-rich slag by sulfation roasting−water leaching.The extraction mechanisms of Mn and Li were investigated by means of XRD,TG−DSC,and SEM−EDS.73.71%Mn and 73.28%Li were leached under optimal experimental conditions:acid concentration of 82 wt.%,acid-to-slag mass ratio of 1.5:1,roasting temperature of 800°C,and roasting time of 2 h.During the roasting process,the manganese-rich slag first reacted with concentrated sulfuric acid,producing MnSO_(4),MnSO_(4)·H_(2)O,Li_(2)Mg(SO_(4))_(2),Al_(2)(SO_(4))_(3),and H_(4)SiO_(4).With the roasting temperature increasing,H_(4)SiO_(4) and Al_(2)(SO_(4))_(3) decomposed successively,resulting in generation of mullite and spinel.The mullite formation aided in decreasing the leaching efficiencies of Al and Si,while increasing the Li leaching efficiency.The formation of spinel,however,decreased the leaching efficiencies of Mn and Li.

开展富锰渣硫酸化焙烧−水浸选择性提取锰和锂的试验,采用XRD、TG−DSC和SEM−EDS详细分析锰和锂的提取机理。结果表明,在酸浓度为82%(质量分数)、酸矿质量比1.5:1、焙烧温度800℃和焙烧时间2 h时,Mn和Li的浸出率分别达到73.71%和73.28%。焙烧过程中,富锰渣首先与浓硫酸反应形成MnSO_(4)、MnSO_(4)·H_(2)O、Li_(2)Mg(SO_(4))_(2)、Al_(2)(SO_(4))_(3)和H_(4)SiO_(4)。随着焙烧温度的升高,H_(4)SiO_(4)和Al_(2)(SO_(4))_(3)依次分解,并形成莫来石和尖晶石相。莫来石的形成有利于降低Al和Si的浸出率而增加Li的浸出率;而尖晶石的形成则会降低Mn和Li的浸出率。