Aldoro’s Kameelburg route produces rare earth and strontium carbonate samples

Kameelburg produces saleable intermediate samples

Aldoro Resources Limited (ASX:ARN) has cleared a significant technical hurdle at its Kameelburg rare earths, strontium and niobium project in Namibia, with independent laboratory work producing both mixed rare earth carbonate (MREC) and strontium carbonate from hard-rock mineralisation.

Testing by CM Solutions Metlab in Johannesburg validated Aldoro’s direct “rock-to-MREC” hydrometallurgical route under ambient temperature and pressure, using a leach residence time of about two hours. The proposed process avoids conventional flotation beneficiation and high-temperature acid baking or roasting, although those potential capital and operating advantages have not yet been demonstrated at pilot or commercial scale.

MREC grade improves the project’s downstream options

The MREC sample assayed 39.6% total rare earth elements, equivalent to 47.5% TREO on an as-dried basis. Aldoro says rare earth oxides represented 85.3% of measured metal oxides, while the product contained 1.1% aluminium, 1.1% iron, 1.8% calcium and combined uranium and thorium of 3.7 grams per tonne.

A moisture-adjusted calculation lifted the indicated grade to about 55% to 57% TREO, or roughly 76% to 78% rare earth carbonate, based on an assumed removable water fraction of 14% to 16%. That is a modelled adjustment rather than a separate product result. The company is targeting MREC purity above 90% through further washing, filtration and residue re-leaching.

Lower acid route delivers strong strontium recovery

The selective 10% hydrochloric acid process reduced HCl dosage to about 400 kilograms per tonne for the master composite and 339 kilograms per tonne for non-magnetic feed, representing reductions of 37% and 47% against the baseline test. Strontium extraction remained between 92.7% and 94.4%, while single-pass neodymium-praseodymium extraction was about 54% to 55%.

Earlier baseline work achieved up to 99% strontium recovery and around 74% rare earth recovery in a single pass. Adding caustic conversion and re-leaching increased cumulative rare earth recovery to more than 89% in the reported test, with the company targeting about 90% overall recovery through optimisation. The same programme also produced a strontium carbonate sample grading 79.2% SrCO3, with more than 99.9% of dissolved strontium precipitated.

Soft ore and niobium by-product add to the flowsheet case

Comminution tests across six drillhole composites classified the ore as soft to medium and non-abrasive. The average Bond Ball Mill Work Index was 12.07 kilowatt-hours per tonne, while the Bond Abrasion Index was just 0.0045, results Aldoro says could support lower grinding energy and equipment-wear costs.

Magnetic separation retained about 97% to 98% of the key rare earths and strontium in the non-magnetic leach feed. It also generated a small niobium-enriched magnetite stream grading 47.4% to 50.6% iron and 1,770 to 1,790 grams per tonne niobium. That stream remains a potential by-product requiring further beneficiation and commercial evaluation, rather than an established revenue source.

Scoping Study must convert laboratory results into economics

The technical announcement follows the WILLETECH funding MOU, under which the proposed RMB2 billion, or about A$430 million, development commitment remains subject to definitive agreements and approvals. Aldoro says the partnership framework is intended to support optimisation, pilot or demonstration-scale work, customer qualification and engineering studies.

Wood Mackenzie pricing inputs cited by Aldoro include an estimated US$18,000 per tonne REO basket value, a long-term MREC price of about US$7,000 per tonne at 60% payability, and about US$7,700 per tonne at the targeted 90% MREC purity. The company also uses an approximately US$2,000 per tonne reference for its roughly 80% SrCO3 product. These are market-study assumptions, not realised sales prices.

Kameelburg’s large resource base, recently reported at 804.5 million tonnes, gives the testwork a substantial geological backdrop, but the next proof point is more practical: whether the flowsheet can maintain its recovery, purity and reagent profile in larger continuous campaigns. The Scoping Study, pilot-scale validation, definitive WILLETECH agreements and customer qualification will determine how much of today’s laboratory promise survives contact with a mine plan.