劉沛靜
(陜西國防工業職業技術學院 化學工程學院, 陜西 西安 710300)
LiCoO2在酸性混合物中酸性焙燒元素的賦存狀態和元素分布分配的研究
劉沛靜
(陜西國防工業職業技術學院 化學工程學院, 陜西 西安 710300)
了解鈷酸鋰(LiCoO2)在酸性環境中的物理化學性質和存在形式,有助于從理論上指導該物質的合成工藝設計以及從報廢LiCoO2中提取有價金屬的工藝設計。將LiCoO2與NaHSO4·H2O和KHSO4分別按摩爾比1∶2.5∶0.5、1∶2.0∶1、1∶1.5∶1.5、1∶1∶2.0、1∶0.5∶2.5的比例混合后進行酸性焙燒,采用 TG-DSC、XRD、SEM、EDS研究了焙燒過程中元素的熱量變化、質量變化、形貌變化。研究結果表明:LiCoO2與NaHSO4·H2O和KHSO4的混合物在焙燒過程中根據鉀、鈉酸式鹽的含量不同,反應產物的存在形式發生著不同形式的變化。XRD的分析結果表明,焙燒產物中Na元素是以KNaSO4的形式存在,K元素是以KNaSO4、KLiSO4、K2Co2(SO4)3這三種存在形式,Li元素的存在方式是以KLiSO4,Co元素的存在形式是K2Co(SO4)3, 從SEM的電鏡中可以看到圖片中可以看出焙燒產物致密,形狀不規則,Co元素在焙燒產物中分布均勻。
LiCoO2;酸性焙燒;賦存形式;元素分布
Abstract: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, LiCoO2was mixed with NaHSO4·H2O and KHSO4respectively 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 LiCoO2with NaHSO4·H2O and KHSO4after 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.
Key words:LiCoO2;acid roasting; Occurrence form; Element distribution
在中國國土資源里面,已經基本上沒有單一的鈷資源的存在,鈷資源基本上都是半生在其他的資源里面,而且含量很少,人類如果需要使用鈷資源,只能從貴重金屬的冶煉過程中和廢物的利用中進行提取,在元素周期表中可以看出,鈷元素是一種稀有金屬元素,由于具有比較高的熔點和良好的穩定性,所以常常在物理化學和生物研究方面有廣泛的用途,在軍事行業(如防彈衣、穿甲彈等)和航空行業(發動機)中也有著不可代替的作用,所以鈷被稱為是一種重要的戰略資源。……