To address these shortcomings, the solution being developed by Penn State with Hertz’s support begins with taking spodumene concentrate, introducing sodium hydroxide, and then proceeding with conventional or microwave roasting which transforms the spodumene into a soluble phase. Next, water leaching is used to recover water-soluble lithium and remove unwanted chemicals. A final acid leach and purification results in a 90% recovery of lithium.
The organizations involved in the project said that, at present, their primary objectives are to optimize the process conditions to maximize the recovery of lithium in water leaching and eliminate the acid leaching process or reduce the chemical consumption, as well as conduct a kinetic study to obtain the required data for pilot scale testing.