WSJ
Just before the Covid-19 pandemic took hold, South African mining veteran George Bennett was offered the opportunity to bid for two waste piles of gypsum, left over from decades of phosphate mining in a small town near the Mozambique border.
Bennett built more than 20 mining projects over his career, but this one really caught his attention. Analysis of samples he took showed that those waste stacks held a treasure trove—high concentrations of the rare-earth minerals needed to make the permanent magnets used to power offshore wind turbines and electric vehicles.
Rare-earth minerals aren’t actually that rare, but it is unusual to find them in sufficiently high concentrations that would make mining them economical. Having a massive pile of them above ground is even rarer. And new sources are highly valuable because China currently controls most of the extraction and refining of rare earths—a dominance that it is looking to maintain through a ban on the export of rare-earth processing technologies, which it introduced in December.
could be a significant non-Chinese source of crucial energy-transition materials, according to Bennett, the company’s chief executive. The company, which was listed in London in 2017, expects to generate a net present value of more than $1 billion from those two South African waste piles, he said.
“There are a lot of rare earth projects…[but] Rainbow is unique in the economics and the environment and carbon footprint associated with the [South African] project. We feel it can be one of the biggest, lowest cost, producers of rare earth oxides in the world,” said Brian Menell, CEO of Techmet, a U.S. government-backed critical-minerals investment company that recently invested $50 million in Rainbow.
Mining is hugely expensive, highly political and can take years to get off the ground, particularly as governments change their policy on mining across election cycles.
Rainbow has been through those struggles. Its mining project in Burundi had been producing rare earths and it had been selling them to Chinese buyers since 2017. Those operations were suspended in 2021 when the local government halted all mining activity in the country to renegotiate the mining code and royalties, according to Bennett.
Fortunately for Rainbow, its Phalaborwa project in South Africa won’t actually involve any digging. The two waste piles of phosphogypsum are above ground and have already been “cracked”—a process where the mined material is crushed and further processed with heat and acid—increasing the rare-earth concentration and thereby reducing the processing that Rainbow needs to do.
