Popis: |
Li+ adsorption onto aluminium hydroxide has been investigated at various temperatures. Experiments were made on two high-salinity geothermal-type fluids in which the lithium concentration reaches values greater than 30 and 50 mmol −1 respectively, in order to study the recovery of lithium from the fluids. Aluminium hydroxide was produced by adding AICl3·6H2O salt and KOH solution to the two reconstituted fluids. Experiments were performed at various pH values, temperatures (20, 50 and 80°C) and AI contents. The results indicate high Li+ adsorption rates for both fluids at 80°C, even under conditions where small amounts of Al salt were added to the fluids. Under certain conditions, the chemical composition of the geothermal fluids had an influence on the Li+ adsorption rate. The presence of certain ions in solution, such as borate, which prevent Li+ adsorption, is therefore discussed. Experiments on the desorption of lithium from aluminium hydroxide using dilute solutions of hydrofluoric and sulphuric acid gave good results for the hydrofluoric acid. |