(西安建筑科技大學(xué) 冶金工程學(xué)院，西安 710055)
摘 要: 以氯化膽堿為氫鍵受體，苯基次膦酸為氫鍵供體，制備膦酸基低共熔溶劑(DES)，研究其浸出鈷酸鋰的性能。考察了浸出溫度、液固比、浸出時(shí)間等因素對(duì)浸出率的影響，利用縮核模型擬合了浸出動(dòng)力學(xué)數(shù)據(jù)，采用紫外-可見(jiàn)吸收光譜和紅外吸收光譜分析了浸出機(jī)理。結(jié)果表明：增加浸出時(shí)間、液固比，升高浸出溫度(70~90 ℃)，可提高鋰和鈷的浸出率。浸出過(guò)程受化學(xué)反應(yīng)控制，浸出鋰和鈷的表觀(guān)活化能分別為26.5 kJ/mol和26.6 kJ/mol。鈷酸鋰的浸出液中，鈷的配位構(gòu)型為四面體，P=O參與了鈷的配位。
關(guān)鍵字: 低共熔溶劑；苯基次膦酸；鈷酸鋰；浸出動(dòng)力學(xué)
（School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China）
Abstract:A deep eutectic solvent (DES) composed of choline chloride (hydrogen bond donor) and phenylphosphinic acid (hydrogen bond donor) was prepared, and the leaching performance of lithium cobalt oxide using the DES as lixiviants was studied. The effects of leaching temperature, liquid-to-solid ratio and leaching time on leaching efficiencies were investigated. The leaching kinetics data were fitted by the shrinking core model, and the leaching mechanism was analyzed by UV-Vis absorption spectrum and FTIR spectrum. The results show that the leaching efficiencies of lithium and cobalt increase with the increase of leaching time, liquid-solid ratio and leaching temperature(70-90 ℃). The leaching process is controlled by chemical reaction and the apparent activation energy values for lithium and cobalt are 26.5 kJ/mol and 26.6 kJ/mol, respectively. In the leaching solution of lithium cobalt oxide, the coordination configuration of cobalt is tetrahedral and oxygen atom in P=O coordinate to cobalt.
Key words: deep eutectic solvents; phenylphosphinic acid; lithium cobalt oxide; leaching kinetics
