Lindian nails rare earths metallurgical testing in Malawi

Lindian Resources has delivered a major downstream step for its Kangankunde rare earths project in Malawi, with Australia’s national nuclear science agency (ANSTO) confirming its monazite ore feed cracks cleanly to a premium mixed rare earth carbonate (MREC) grading 54 per cent total rare earths oxide concentrate (TREO) and carrying an elite 20 per cent of the lucrative magnet rare earths neodymium and praseodymium (NDPR)

ANSTO — the Australian Nuclear Science and Technology Organisation — is widely regarded as one of the global leaders in rare earths metallurgy and radioactivity classification and its testing regime carries weight with separation plants, regulators and downstream processors worldwide.

Kangankunde’s concentrate itself comes in hot at 55.9 per cent TREO, with monazite making up 83 per cent of the mineral mix. In simple terms, that means the raw material is naturally rich in the minerals needed to make magnetic rare earths and contains minimal waste minerals that typically complicate cracking.

Another key feature is its radiation profile. ANSTO again classified the concentrate from Kangankunde as “non-radioactive for transport” — a rare outcome in the monazite world where thorium and uranium levels often trigger Class 7 handling rules. Avoiding those requirements significantly widens the field of potential customers and can materially reduce compliance overheads.

The testwork used a standard sulphuric-acid bake — a well-known industrial method that “opens up” monazite so the rare earths can dissolve. ANSTO extracted 91–94 per cent of all rare earths and 93–97 per cent NdPr, with more than 90 per cent of the metals dissolving in the first hour of leaching. That sort of rapid response typically supports shorter tank residence times and a more forgiving operating window in a full-scale plant.

From there, the leach solutions were cleaned up to remove calcium, phosphorus, iron and other gangue elements while retaining more than 90 per cent of the rare earths in solution. That left a purified liquor ready for precipitation into a saleable carbonate.

The final mixed rare earth carbonate came out at 54 per cent TREO, with 10.7 per cent Nd2O3+Pr6O11, reflecting Kangankunde’s strong magnet-rare-earths bias. Uranium and thorium in the product were below analytical detection limits, removing the need for an additional polishing step that many other monazite projects must rely on to meet downstream specifications. That simplicity can translate directly into lower operating costs and smoother acceptance into separation plants.

Across the entire circuit — bake, leach, impurity removal and carbonate precipitation — overall recoveries came in at 92 per cent TREO and up to 97 per cent NdPr, effectively capturing almost all the value present in the original concentrate.

The flowsheet itself uses familiar reagents, ambient-temperature leaching and standard unit operation, reducing development risk and removing the dependency on novel or unproven technologies. ANSTO is now working to optimise acid consumption, already sitting in the competitive range of 1.2–1.4 tonnes of sulphuric acid per tonne of concentrate and is running a parallel caustic-conversion program to maintain optionality for different downstream customers.

With a clean concentrate, a high-grade carbonate product and ultra-low radionuclides at both ends of the circuit, Lindian now has the type of independently verified metallurgical foundation that downstream processors tend to favour. The company will feed the data directly into ongoing engagement with separation plants and strategic groups that prefer feedstocks requiring minimal compliance overheads and offering strong NdPr exposure.

Put simply, these results show Kangankunde can deliver a premium, specification-ready MREC using a standard flowsheet, with high recovery, low complexity, low radionuclides and strong REE exposure, exactly what customers and partners are looking for.

Kangankunde’s ore reserve currently stands at 23.7 million tonnes (probable) grading at a very high 2.9% TREO for 676,000 tonnes of contained TREO, including 20% light magnet rare earths neodymium-praseodymium. The current mine life for the project is a whopping 45 years and a feasibility study completed in June 2024 demonstrated that the project has an NPV of US$794 million and one of the lowest capital (US$40m) cost structures of rare earths projects globally.

This low-cost structure is supported by a technically low risk and robust Stage 1 project, involving mining operations and a simple mineral processing plant. The project is located close to good supporting infrastructure which includes proximity to the main M1 highway, rail lines to ports and high voltage transmission lines.

The final investment decision in August for the project’s Stage 1, paralleled by completion of a A$91.5 million capital raise, allowed Lindian to fully fund the project to first production, scheduled for Q4 in 2026.

The strength of the placement provided flexibility for the Lindian board to advance Stage 2 expansion planning in parallel. Engineering and feasibility works are being progressed to evaluate production scenarios well above the Stage 1 base case, supported by the recently approved expansion of the Kangankunde mining licence.

In early August, Lindian executed a binding US$20m (~A$32m) secured construction term loan facility and offtake agreement with Australia’s Iluka Resources, establishing a long-term strategic partnership for the development of Kangankunde and the offtake of its product. The agreement covers the supply of 6,000 tonnes per annum of premium monazite concentrate for 15 years, with Iluka also granted a right of first refusal over up to a further 25,000 tonnes per annum from the proposed Phase 2 expansion, subject to providing 50% debt funding support for expansion capital.

Iluka is developing Australia’s first fully integrated rare earths refinery at Eneabba in Western Australia and has secured offtake rights over Kangankunde. The Eneabba refinery is being developed in partnership with the Australian Government. The deal with Iluka provides Kangankunde and Lindian with a multi-decade processing solution in a stable government-backed, globally strategic supply chain.

With the unique mineralogy of Lindian’s Kangankunde project’s monazite rich ore allowing relatively high levels of TREO recovery, the project is regarded as one of the world’s largest and highest-grade undeveloped rare earths deposits outside China. Its low-cost economics remain robust even at recent lower but currently resurgent spot prices for the magnetic rare earths neodymium and praseodymium and this week’s met testing has nailed what can often be a stopper for good looking but technical projects.

Is your ASX-listed company doing something interesting? Contact: matt.birney@wanews.com.au