Highlights

• Rainbow Rare Earths develops a breakthrough process to extract rare earth elements from phosphogypsum waste.
• The initial concentration of rare earth elements is over 55% and the purified concentration is 93%.
• New extraction method reduces processing volume.
• Promises lower-cost rare earth production from industrial waste streams.
• Potential to add resilience to Western rare earth supply chains.
• Creates an alternative production route outside traditional mining.

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Rainbow Rare Earths’ new Johannesburg testwork isn’t fluff. The latest flowsheet delivers a mixed rare-earth carbonate (MREC) averaging >55% TREO and a purified product >93% TREO—both above typical refinery specs. Continuous ion exchange (CIX) plus precipitation also cuts volumetric flow into final separation from ~340 m³/h to just 7–10 m³/h, with ~65% overall recovery validated via lock-cycle testing. Together, these point to a smaller, cheaper separation step if replicated at scale.

In A Nutshell

Rainbow Rare Earths says new lab work in Johannesburg shows its process can make a high-grade rare-earth mix straight from waste stacks. The first product is over 55% rare earths, and after a simple clean-up, it’s over 93%—better than what refineries usually ask for. Their chemistry (a kind of “smart filter” called continuous ion exchange plus a settling step) also shrinks the liquid stream that must go through the expensive final separation, from about 340,000 liters an hour to just 7,000–10,000. They’re recovering ~65% of the metals in these tests, too.

Why this matters (in practice):

• Smaller plant, lower costs: Less liquid to process means smaller equipment, less power, and fewer chemicals.
• Easier to sell: Cleaner, higher-grade feed is simpler and cheaper to finish into saleable rare-earth oxides.
• If it scales: If these results hold outside the lab, it points to a cheaper, faster route to rare-earth supply from waste rather than new mines.

Waste to Wallet—what the reporting gets right

Mining Weekly (opens in a new tab) correctly spotlights the phosphogypsum route (legacy fertilizer waste, not fresh ore), Rainbow’s in-house CIX purification, the Mintek collaboration, and trade-off studies feeding a Definitive Feasibility Study (DFS). The JORC resource sits at 35.0 Mt @ 0.44% TREO across two stacks at Phalaborwa—supporting the brownfield, long-life thesis.

The Loose Plank: “150,000 t produced”

One claim—“150,000 tonnes of rare earths will be produced”—conflates contained TREO in the stacks with planned output. Rainbow’s published PEA models ~1,848 t/year of separated NdPr/Dy/Tb oxides over ~14.2 years—about 26,000 t total, not 150,000 t of REO. Keep the 150 kt figure as resource content, not a production forecast.

Marketing vs. Margins

Management’s line that Phalaborwa could be a “very low-cost, highest-margin” project is forward-looking, not audited. That said, the higher-grade MREC and tiny separation feed are exactly the mechanics that can reduce capex/opex. The DFS, not lab headlines, must prove unit costs, price sensitivities, and capital discipline.

Why supply-chain folks should care

China’s export licensing on select medium/heavy REEs and magnets highlighted the fragility of Western supply lines. Rainbow says offtake interest has risen since those curbs. If the DFS numbers and financing land, a South African waste-to-REE route producing NdPr and SEG+ (incl. Dy, Tb) would add useful resilience outside China.

So What to Watch Next

• DFS outputs: recovery, reagent/power balance, and how primary leach design shifts the cost base.
• Separation spec: confirmed purity for NdPr oxide and SEG+ product; tolling vs. in-house options.
• Funding path: timing and structure to go from lab to plant against the PEA baseline.

Bottom line: The purity and flow-reduction gains are real and material. Just don’t confuse ~150 kt contained TREO with ~26 kt modeled life-of-mine output. Phalaborwa’s edge is process simplicity on waste feedstock—now it must convert that into bankable economics and tonnes.

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