Mining Mirror May 2017 - Page 11

Exploration and projects deposit is the size of the monazite grain carrying the rare earths. The grain is larger than normal, at about 250–300 microns in diameter. This means that the monazite requires less milling, further reducing costs. Most competitors need to mill their monazite down to 50 microns. This increases costs and requires large amounts of energy. Copper, for example, needs to be milled to 75 microns. In addition, at Steenkampskraal, 59% of the mass of the monazite is total rare earth oxides. As a result, when milling, less dust is created because of the high density, further reducing costs and lessening any negative environmental impact. The chemical treatment process is also less complex, resulting in reduced capital and operational expenditure.  In terms of the mine’s thorium deposits, the latest mineral resource estimate indicates the presence of 11 700 tons of thorium in the Steenkampskraal deposit. In October 2014, the Colorado School of Mines published a report entitled Thorium: does crustal abundance lead to economic availability. The report considers the possibility that thorium could be used as a nuclear fuel and that the demand for thorium could eventually rise to nearly 4 000 tons per year. The report includes studies of where this thorium would be sourced and states that the Steenkampskraal mine in South Africa will be the lowest-cost producer of thorium in the world, with an estimated production cost of USD3.56 per kilogram. The second cheapest producer has an estimated production cost of USD7.98 per kilogram, and the third cheapest with a production cost of USD8.01 per kilogram. The report indicates that the three lowest-cost producers could together produce about 3 718 tons of thorium per year, which is about the quantity that the report indicates could be required by the nuclear industry in the future. “Steenkampskraal expects to play an important role in the development and introduction of thorium as a nuclear fuel,” says Blench.  Blench adds that Steenkampskraal is designing a small, modular, low-cost, helium-cooled thorium pebble-bed modular reactor, known as the HTMR100. “It will use the thorium mined at Steenkampskraal and Steenkampskraal’s locally designed thorium/uranium pebble fuel. This is ideal for areas, such as parts of Africa, that are experiencing acute power shortages with underdeveloped or non-existing power infrastructure,” says Blench. Steenkampskraal is designing the factory to produce the pebble fuel for the HTMR100. The fuel presents no risk of meltdown, such as that experienced at Fukushima.  Blench says that Steenkampskraal’s vision is to be the building block and provider of the foundation of a rare earths supply chain, independent of China. This strategy covers four key areas: mining thorium and rare earths at Steenkampskraal; designing a safe thorium-based nuclear reactor; designing the thorium/uranium pebble fuel for this new HTMR100 reactor; and testing and supplying safe thorium/uranium and thorium/plutonium pellet fuel for existing light water reactors(LWRs), of which there are about 350 operational worldwide. b MAY 2017 MINING MIRROR [9]