Conventional processing of concentrate from the Grandao deposit using calcination/acid roasting and water leaching extracted up to 94.6% lithium.
A planned third stage of treatment to produce battery-grade chemicals has been temporarily postponed due to coronavirus (COVID-19) related restrictions in the US.
Savannah, added, though that impurity levels are manageable from the first two stages and production of battery-grade lithium hydroxide should be readily achievable from the third stage of testing.
In a statement David Archer, Savannah's chief executive, said: “These latest results give a further clear indication that battery-grade lithium chemicals can be produced efficiently from Mina do Barroso concentrate. Test work will continue over the coming months to complete the programme and to help refine our understanding of the behaviour of the material.
“We expect the results to provide more evidence for our potential customers regarding the suitability of the project's lithium concentrate for refining into lithium hydroxide, the key lithium-ion-battery chemical."