United Lithium Corp. announced completion of a series of roasting tests utilizing spodumene feedstock to develop and optimise a more sustainable lithium extraction flowsheet. Sixteen tests to optimize chemical roasting and several tests using microwave energy were completed in the current round of testwork.

These tests have provided excellent results and led to Li2O recoveries ranging from 70.57% to 97.30%. Data will be used to develop a final flow sheet along with previously released results and ongoing test work. The final flow sheet will be implemented in pilot plant testing later this year.

Roasting tests were completed at Process Research Ortech on spodumene concentrate to produce a final lithium oxide product. The goals in these tests were to examine the feasibility of using microwave energy in the roasting stage to lower energy demand. All tests were completed at atmospheric pressure, but with varying temperatures, energy levels, and acid concentrations.

The spodumene concentrate was produced by flotation utilizing conditions as reported in Phase 1 test results press released October 27, 2021. Five calcination tests were completed on this flotation concentrate followed by 16 roasting and 16 water leaching test to evaluate the impact of calcination temperature and conventional versus microwave roasting on the recovery of Li2O. Results are reported.

The tests to evaluate the effect of additives addition to the flotation concentrate at lower calcination and roasting temperatures are in progress.