Infinity Lithium has reached a significant milestone after successfully recycling and reusing the potassium sulphate used to leach lithium from the micas sourced from its San José project in Spain.
In the roasting process, sulphates were added to the ore before roasting, allowing the lithium to be leached into fresh water without the need for sulphuric acid during the post-roast leaching process, the company said.
Removing the need for acid is a major boost to the project’s environmental credentials compared to other hard rock lithium processing operations, which is a major consideration given San José’s location in Europe, one of the world’s most environmentally conscious jurisdictions.
The types of sulphates required are deposit specific with the company using a mixture of potassium sulphate and sodium sulphate chemicals, both of which are readily available in Spain.
Management said it expects to ultimately achieve a 90% to 100% recycling rate for the potassium sulphate, which will minimise the amount of “fresh” sulphate required during the production cycle.
Importantly, the pre-feasibility study level leaching test work continues to underpin the assumptions made in the lithium hydroxide scoping study released in the fourth quarter of 2018.
Test work will now move to the production of lithium hydroxide using the recirculated potassium sulphate materials.
Infinity is now finalising capital and operating cost optimisation that will include the use of recirculated potassium sulphate, which will, in turn, enable the company to complete and release the pre-feasibility study.
San José holds a JORC-compliant mineral resource of 111.3 million tonnes grading 0.61% lithium oxide and 206 parts per million tin.
While this resource is contained within the comparatively lower grade lepidolite mica mineralisation, a commercial gas pipeline running straight past the project just 1km away, provides a ready source of energy for the intensive roasting process to extract the lithium.
The project is also ideally placed geographically to satisfy the increasing European demand for battery-grade lithium hydroxide to support local manufacture of lithium-ion batteries, or “LIB”, for the electric vehicle, or “EV”, sector and potential domestic energy storage considerations.
This proximity has been recognised by the European Battery Alliance, which considers the project to be a potential cornerstone in its goal of creating a competitive LIB manufacturing value chain in Europe.
Infinity also has a memorandum of understanding with Spanish industrial group Ercros SA for the supply of major reagents, including caustic soda, that would also be required in the production of lithium chemicals at the San José project.
By Matt Birney
