Latin Resources has edged closer to commercial production at its Colina deposit in Brazil after proving up its ability to produce a 5.5 per cent lithium oxide concentrate, with a 93.1 per cent recovery rate.
The company says the results are a reliable indication of the potential for simple and cost-effective commercial lithium production by using the dense media separation (DMS) process.
Management says it was encouraged by the results of using the DMS method, which is described as a pre-concentration of minerals leading to the production of a high-weight, low-assay product that may otherwise have been rejected as waste.
The company used a DMS pilot plant to beneficiate spodumene from waste and says the outcome proved up a reliable indication of the method’s commercial potential. It says the grade of the produced concentrate and the “impressive” recovery rate proves the ability of Colina ore to be produced using a DMS-only flowsheet.
These latest metallurgical test results very clearly demonstrate the amenability of the Colina spodumene pegmatite to simple DMS processing, validating assumptions drawn from the initial benchtop scale HLS test work. DMS processing is commonly used in the spodumene lithium sector and has been shown to have significant cost saving implication for both capital and operating costs. The company is currently in the final stages of completing a PEA based on the Colina Lithium Deposit, which will include estimates of both Capital and operating costs for the project. A much larger DMS and other test work program will be undertaken in Q4 of this year utilising more than 2,000kg of spodumene pegmatite samples from Colina. Latin Resources vice president of operations (Americas) Tony Greenaway.
DMS uses centrifugal units, or cyclones, which utilise high speed and tangential pumping to create a vortex within the vessel. Any mineral with a higher density than the medium will be subject to greater centrifugal forces and will be pulled to the outer edge of the vortex, while any lower-density mineral will remain at the centre. The differing minerals are then removed through separate discharge lines as a “sink” or “float”.
The DMS pilot testwork, completed by SGS Lakefield laboratories (SGS), used 137kg of diamond core samples from 35 Colina deposit drillholes to create a single representative sample grading 1.31 per cent lithium oxide. The sample was then crushed and screened to produce the final feed-grade material at 1.38 per cent lithium oxide.
A subsample of the feed was processed for benchmarking using the heavy liquid separation (HLS) method that simulates the separation of minerals under ideal conditions and is the typical preliminary step to pilot-scale DMS testing. The HLS recovery rate was 95.4 per cent, just 2.3 per cent higher than DMS recovery.
Latin says it will use the pilot results to inform its upcoming preliminary economic assessment for Colina that is due for release this quarter. Results from further bulk sampling and more extensive tests on the deposit’s ore will feed the definitive feasibility study that the company expects to release in the first half of next year.
The Colina deposit, part of Latin’s 100 per cent-owned Salinas lithium project in south-eastern Brazil, has a mineral resource estimate of 45.2 million tonnes at 1.32 per cent lithium oxide, representing a lithium carbonate equivalent of 1.5 million tonnes.
The classification includes 0.43 million tonnes at 1.34 per cent lithium oxide in the measured category, 29.7 million tonnes at 1.37 per cent lithium oxide in the indicated category and 15 million tonnes at 1.22 per cent lithium oxide in the inferred category.
The Brazilian State of Minas Gerais, where Latin has tenements covering more than 38,000 hectares, is well serviced by infrastructure, roads, hydroelectric power, water and the port city of Vitoria in the neighbouring Espirito Santo. The province is renowned for its efficiency in issuing drilling permits and environmental approvals.
Latin has three diamond rigs operating at Colina and other regional targets and says the coarse spodumene mineralisation, which has been visually identified in diamond core in multiple holes, may extend a significant distance to the south-west of its existing mineral resource.
Latin’s share price jumped to a peak of 38 cents in intraday trading on the back of its latest news after closing yesterday at 36c.
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