The COOl+ Process

 

The goal of the COOL+ Process is the selective recovery of lithium as well the production of geopolymers from the aluminosilicate solid residue and thus a holistic valorisation (zero-waste concept) of lithium containing ores. 

In a first step the lithium ores are thermally treated at 950-1200 °C. Afterwards, the material is suspended in water and leached with supercritical CO2. The liquid phase, containing lithium carbonate (Li2CO3), is separated by filtration and concentrated by electrodialysis. Through evaporation lithium carbonate (Li2CO3) is precipitated as highly pure product.

Since the lithium concentration in the raw material is low (< 5 wt.%) the main part of the ore remains as solid after leaching. In the framework of a zero-waste concept this residue is used for production of geopolymers.