The rare earths industry in Africa is growing. Companies are buying up assets and determining their contained value, but giving less attention to the downstream process flow sheets necessary to prove their viability, writes Laura Cornish.It is common knowledge that China, the world’s largest rare earths producer and supplier, is no longer exporting the majority of its product, but is instead keeping it for its own use. This has resulted in the rebirth of the rare earths industry outside of China, which was last active in the 1970s. Rare earths are a group of 17 elementsthat are being increasingly used in the shift to cleaner energy sources, such as magnets in wind turbines, hybrid vehicle batteries and catalysts to reduce automobile exhaust emissions. The rest of the world is taking a stance against the Chinese monopoly, and is sourcing and securing its own supply, resulting in a more price competitive market. Indian Rare Earths, Australia’s Lynas Corporation and US-based Molycorp alone provide plenty of rare earth material and Africa wants its piece of the rare earths pie. “While producing a rare earth concentrate is the easy part, the secondary refining process separating the rare earths into their individual components is the challenge. And for those who have succeeded in conceiving a working formula, they are highly unlikely to share it,” explains Mintek’s chief scientist, Olga Yahorava. This is a challenge for African-focused rare earth mining companies, which have emerged in South Africa’s Western Cape as well as in Namibia, Tanzania and Malawi. Because every rare earth deposit has its own unique gangue mineralogy, each deposit also requires its own flowsheet to understand its processing options. As a result, we have been developing processing sheets for numerous clients targeting production of a high-grade rare earth oxide concentrate,” says Marthie Kotze, senior hydro metallurgist at Mintek. In the past two years, Mintek has had major rare earth project enquiries, based on relatively low-grade ores that are difficult to upgrade physically. But due to the current high value of rare earths, more options have become available to treat low-grade materials, Kotze continues. While this alone indicates the significant role Mintek is playing in the development and progression of the African rare earths sector, the government-funded organisation may hold the pivotal key to unlocking the real potential that the African continent has to offer to meet its own needs – and global demand.
“The Department of Energy has allocated a portion of its medium-term expenditure framework funding to Mintek, enabling us to develop rare earth refining technologies over the next two years. The long-term view and intention, based on our findings, is to develop a centralised rare earth refinery to service the African continent’s rare earths miners. Considering the lack of rare earth consultants, particularly with regards to refining, we believe our role is an essential one,” Kotze announces.For those companies looking to take their rare earths fully downstream, a central refinery will ensure their viability. “It is not viable to build a refinery with less than 20 000/30 000 tpa with a lifespan of between 15 and 20 years. A lot of companies won’t be able to mine or process those quantities meaning a central refinery is the perfect solution.” The target, Yahorava continues, is to demonstrate Mintek’s ability to produce specific pure rare earths by April 2014, including lanthanum, cerium, praseodymium, neodymium, middle rare earths or samarium, europium and gadolinium(the latter three are collectively referred to as SEG or heavy rare earths). These specific metals have been targeted upfront as they make up 80% of South Africa’s rare earth deposits. “There is no technology that can develop the design criteria for all the rare earths to produce concentrates and refine them afterwards. It is like we are starting from scratch,” Kotze notes. Mintek has already purchased 90% of the equipment it requires to establish a pilot plant for the rare earths refining test work. It will be fully automated and demonstrate the metallurgical behaviour of individual rare earths and separation capabilities. “Our study will also examine how to remove thorium and uranium before the refining stage and will be more cost effective than the typical flow sheets that Chinese companies use, as far as we understand. It is essential to note that while China’s rare earths industry may be more mature, it has not evolved or been improved for the past 30 years, making it ineffective and unfriendly towards the environment,” Yahorava outlines. Mintek is also working with numerous international rare earth clients, particularly in South America, which is also lacking expertise in this particular field.