摘要
The behavior and mechanism of Li leaching from lithium aluminum silicate glass-ceramics which can be used as a secondary source of Li using aqueous NaOH solution was investigated.The Li leaching efficiency is increased with increasing concentration of NaOH, specific surface area, and reaction temperature.When leached under optimum conditions, 2 mol/L NaOH, 53 μm particle undersize, 1:10 solid/liquid ratio, 250 r/min stirring speed, 100℃ reaction temperature, 12 hr, the Li leaching efficiency was approximately 70%.However, when the leaching experiment was performed for 48 hr, the concentration of Li+ ions contained in the leach liquor decreased from 1160 to 236 mg/L.To investigate the origin of this phenomenon, the obtained leach residue was analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy.These analyses show that zeolite was formed around the lithium aluminum silicate glass-ceramics, which affected the leaching of by adsorbing Li+ ions.In addition, using the shrinking-core model and the Arrhenius equation, the leaching reaction with NaOH was found to depends on the chemical reaction of the two reactants, with a higher than 41.84 kJ/mol of the activation energy.
基金
supported by the Technology Innovation Program(No.20003877,Development of eco-friendly electrochemical recycling system for production of high purity(>99.5)lithium and lithium compounds)funded By the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
