Lithium adsorption on amorphous aluminum hydroxides and gibbsite

摘要

Lithiu m (Li) adsorption on both amorphous alumin um hydroxides and gibbsite was studied. For the amorphous Al(OH) 3 the adsorption was found to be pH dependent. Generally, 1.6 times more Li was adsorbed at initial pH value 8.0 compared with pH value 6.50. Gibbsite adsorbed 11.6 to 45.5 times less Li quantities compared with amorphous Al(OH) 3 . Lithium adsorption was not depended on equilibrium times. It remained stable for all equilibrium times us ed. Lithium quantities extracted with 1N CH 3 COONH 4 pH 7 , represent the physical adsorption, while the remaining Li that was adsorbed on Al(OH) 3 , represents the chemical adsorption. During the desorption process 19% of Li extracted with NH 4 + , represents t he physical adsorption, while the remaining 81% of Li, which was adsorbed represents the chemical adsorption. In gibbsite, 9.6% of Li represents the physical adsorption and 90.4% the chemical one. The experimental data conformed well to Freundlich isotherm equation.