LiCoO_2在酸性混合物中酸性焙烧元素的赋存状态和元素分布分配的研究

了解钴酸锂(LiCoO_2)在酸性环境中的物理化学性质和存在形式,有助于从理论上指导该物质的合成工艺设计以及从报废LiCoO_2中提取有价金属的工艺设计。将LiCoO_2与NaHSO_4·H_2O和KHSO_4分别按摩尔比1∶2.5∶0.5、1∶2.0∶1、1∶1.5∶1.5、1∶1∶2.0、1∶0.5∶2.5的比例混合后进行酸性焙烧,采用TG-DSC、XRD、SEM、EDS研究了焙烧过程中元素的热量变化、质量变化、形貌变化。研究结果表明:LiCoO_2与NaHSO_4·H_2O和KHSO_4的混合物在焙烧过程中根据钾、钠酸式盐的含量不同,反应产物的存在形式发生着不同形式的变化。XRD的分析结果表明,焙烧产物中Na元素是以KNaSO_4的形式存在,K元素是以KNaSO_4、KLiSO_4、K_2Co_2(SO_4)3这三种存在形式,Li元素的存在方式是以KLiSO_4,Co元素的存在形式是K2Co(SO_4)3,从SEM的电镜中可以看到图片中可以看出焙烧产物致密,形状不规则,Co元素在焙烧产物中分布均匀。

Research on Existent State and Distribution of Elements During Roasting LiCoO2 in the Acid Mixture

Knowing physical and chemical properties and existent state of cobalt acid lithium(LiCoO2) in acidic environment is helpful to the theoretical design of synthetic process of the material and to the design of extracting process of valuable metals form discarded LiCoO2.In this article, LiCoO2 was mixed with NaHSO4·H2O and KHSO4 respectively according to the mole ratio of 1:2.5:05,1:2.0:1.0,1:1.5:1.5,1:1.0:2.0,1:0.5:2.5, and then the mixtures were roasted in acidic environment.TG, DSC, XRD, SEM and EDS were used to study calorie change, quality change and morphological change of the element in the process of roasting. The results showed that the existence forms of the reaction product of the mixture of LiCoO2 with NaHSO4·H2O and KHSO4 after roasting were different because potassium, sodium acid salts' content was different. XRD analysis showed that the existence form of Na element in roasted product was KNaSO4, the existence forms of K element were KNaSO4,KLiSO4and K2Co(SO4)3,the existence form of Li element was KLiSO4,the existence form of Co element was K2Co(SO4)3. SEM electron microscope showed that roasted product was density and irregular shape, Co element evenly distributed in the calcined product.