Lindian Resources has backed up positive recovery results from testwork on ore from its giant Kangankunde rare earths project in Malawi with concentrate grades ranging between 55 per cent and 68 per cent total rare earth oxides (TREO).
The company says its latest metallurgical test results confirm achievable recoveries of 70 per cent TREO, in line with results delivered in April last year.
Previous metallurgical testwork was based on selective and bulk surface samples. However, during the final stages of a core drilling campaign last year, metallurgical drillhole samples were collected from areas where initial mining is planned.
Lindian drilled seven metallurgical drillholes within its recently-released mineral resource to prepare eight testing composites. Multi-gravity separator (MGS) testing was conducted by Coremet in South Africa, with concentrate grade from the circuit averaging about 30 per cent TREO – representing a significant upgrade from feed grades.
The company says the success of the MGS testwork resulted in a reduction of screens and the elimination of spirals and shaking tables from the plant design.
Pilot-scale magnetic separation testwork was conducted by Nagrom laboratories in Perth where the product from the MGS circuit was upgraded to concentrate grades ranging from 55 per cent up to 65 per cent TREO in pilot-scale testing.
Management says it is now in the final stages of a metallurgical variability testing program, with results set to guide mine planning schedules so that grade, recovery and rock-type variations can be used in association with mine and process plant production predictions.
Once completed, the final testwork results will be used to complete mine design studies and production forecasts in the company’s upcoming feasibility report.
Lindian Resources executive chairman Asimwe Kabunga said: “The results are key for defining OPEX for our pending Feasibility Study for Stage 1 mine development and will be instrumental in benchmarking Kangankunde’s concentrate grade and recoveries against existing producers. We expect the results will showcase Kangankunde’s very robust project economics.”
The company recently revealed its maiden mineral resource estimate for Kangankunde, outlining 261 million tonnes at an impressive grade of 2.19 per cent TREO. It has highlighted a lower-end exploration target of 400 million tonnes at 2 per cent TREO, with an upper-range figure at a whopping 800 million tonnes grading 2.7 per cent TREO for its central carbonatite prospect.
The current mineral resource shows 5.7 million tonnes of contained TREO in the inferred category. An estimated 1.2 million tonnes comprises the critical neodymium-praseodymium element, coupling for an average content amounting to about 21 per cent of the overall resource estimate.
Lindian chief executive officer Alistair Stephens said the company plans to report final assay results from resource definition drilling this month, in addition to a completed mine design and scheduling.
In February, management revealed high-grade rare earths running up to 7.15 per cent TREO at Kangankunde following a geological mapping and sampling campaign.
The company says its most recent work shows that outcropping carbonatite prospects both north and south of the project are highly mineralised with rare earths. It says 17 of 21 samples taken from two discrete outcrops in its Malawi project area returned grades ranging from 2.07 per cent TREO to the high 7.15 per cent.
With plans on the cards to announce a first-stage development construction contract for Kangankunde ahead of its planned feasibility study, Lindian is making impressive progress at its Malawi-based operation.
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By Michael Philipps
