EMH, which claims Cinovec is the fourth largest non-brine deposit in the world and a globally significant tin resource in its own right, has been working to optimise the roasting process and has been able to repeatedly push recoveries in the leach circuit to 94% in recent testing.
Improvements in the leaching and roasting processes have led to estimates of a 7% increase in lithium recovery over that used in the preliminary feasibility study, but that these will lead to a 10% improvement in cash margins for the life of the project.
The PFS had already indicated that Cinovec could be a low-cost producer, in the bottom half of the global cost curve.
The use of low-cost waste gypsum from local power plants as a roasting reagent is also expected to deliver a major cost benefit to the project by removing high input costs for hydrated lime and sodium sulphate as the gypsum should be available at a highly competitive price, and it will offer a significant positive environmental outcome for the region, according to EMH.
Any sodium sulphate produced through the lithium carbonate precipitation can also be recycled, meaning there is no issue with the sale or disposal of the material, which had been identified as challenging.
The company will now move into locked-cycle testing to finalise confirmation of the flowsheet all the way through to the production of battery grade lithium carbonate, and to test the larger scale roasting technology using some 3t of lithium concentrate that is being separated from 15t of ore.
The confirmation work will be completed within several months, and will end with production of lithium hydroxide.
Cinovec has a total indicated mineral resource of 348Mt at 0.45% lithium oxide and 0.04% tin, and an inferred resource of 309Mt at 0.39% Li2O and 0.04% tin, containing a combined 7Mt of lithium carbonate equivalent and 263,000t of tin with probable reserves supporting about 20 years of production.
A preliminary mining permit was issued last year and work to complete the definitive feasibility study is ongoing.
EMH shares closed up 6.4% yesterday to A41.5c, but have almost halved over the past year. The company was capitalised at $58.7 million and it had about $2.5 million cash at the end of the March quarter.