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Mining Weekly has just visited the laboratories that Rainbow Rare Earths has established very innovatively on the northwestern fringe of Greater Johannesburg as part of its journey towards completing a definitive feasibility study that should see a wide range of South African rare earths enter the market next year to help to satisfy soaring global demand.
Remarkably, all the rare earths are being sourced from material on a waste dump in Phalaborwa, Limpopo, which is giving South Africa a significantly low-cost high-value lead-in to the commercial production of rare earths needed by the booming permanent magnet market.
Rainbow Rare Earths senior metallurgist Roux Wildenboer, who took the Mining Weekly team around the laboratories, ended the tour by displaying a handful of what he described as "good, final, high-quality product. We're almost at the finish line. It's home stretch for us now. So, exciting times ahead." (Also watch attached Creamer Media video.)
That is the extent of advanced development that the London-listed Rainbow has reached, in an effort that positions South Africa superbly to take full advantage of becoming a highly competitive supplier of one of these green economy commodities.
Historically, there was a massive quantity of phosphogypsum generated as waste from phosacid production of the State-owned Foskor in Phalaborwa.
Now, 35-million tons of it will enable 17 years of production of separated rare earth oxides for direct sale into end-use manufacture.
Meanwhile, Rainbow is leasing laboratory premises from the State-owned Mintek, in Randburg, where Mining Weekly witnessed advanced process development, reagent consumption optimisation, a flow sheet that is close to final form, and most noteworthy of all, a pilot plant.
As final design parameters are precisely identified, the pilot plant is opening the way for scale-up and categorical proof that the process of taking the feed material downstream for on-site refinement works well.
The idea is to have a steady stream of high-value rare earths being produced at low enough volume for even a DHL overnight express service to deliver it to those in urgent need.
Rainbow is working towards publishing a definitive feasibility study (DFS) in 2026 and then going into full-scale construction as fast as it can.
It is important to point out that the Phalaborwa rare earths project has none of the traditional costs associated with blasting, crushing, milling, and flotation that production from typical hard rock phosphate rare earth ore requires elsewhere in the world.
Rainbow has the major advantage of being able to use already cracked rare earth host feed material on surface that gives it a headstart over everyone else and the large quantity and highly concentrated material is readily leachable. Being above ground, the resource also lends itself to drone over flights, density measurement, and being able to arrive at an accurate calculation have how much rare earth is available.
LABORATORY TOUR
In one section of the pilot plant, Mining Weekly was shown how gypsum from site was making contact with a sulphuric acid solution, ahead of being leached in one of several heated, agitated tank reactors, all of which are South African manufactured. In that process, the rare earths are extractable and kept in a leach solution in another section of the pilot plant.
The locally manufactured continuous ion exchange (CIX) unit shown to us had 30 columns each containing small resin beads that help to extract the rare earths from the leach solution.
In passing the leach solution through the CIX, the resin adsorbs the rare earths, but not the other impurities. During the CIX process, the rare earth concentration is increased tenfold, so if two grams a liter in the solution ...

South Africa’s low-cost high-value rare earths heading for 2026 global market entry

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