Lithium and rubidium extraction from zinnwaldite by alkali digestion process: Sintering mechanism and leaching kinetics
2013
Abstract
Lithium and rubidium were extracted from zinnwaldite sintering with CaCO3 powders and water leaching the obtained sinters - the alkali digestion process. The experimental results showed that sintering proceeded in three partly overlapping stages: (1) decomposition of zinnwaldite at temperature up to 800 °C, (2) formation of new phases in the temperature range between 750 and 835 °C, and (3) formation of amorphous glassy phase at temperature above 835 °C.
The optimal extraction efficiencies of 84% of lithium and 91% of rubidium were achieved at sintering temperature of 825 °C and leaching temperature of 95 °C.