Mining Mirror May 2017 - Page 10

Exploration and projects Steenkampskraal confirms high-grade thorium The local community in the Western Cape has high hopes for a new mining project. S teenkampskraal Holdings has once again confirmed the presence of extremely high grades of thorium and rare earth elements at its project close to Vredendal on the west coast of South Africa. According to Trevor Blench, chairperson at Steenkampskraal, the thorium (Th) and rare earth elements (REEs) are the highest grades in the world. “At an average of 2.14% Th and 14.4% REE, with REEs in some areas as high as 45% TREO + Y2O3 [total rare earth oxide + yttrium oxide], this is an impressive deposit,” says Blench. Blench says the Steenkampskraal project has many favourable attributes, including its mining- friendly jurisdiction, well-established local infrastructure with established access to the underground mine, high-grade REE orebody, continued exploration potential, and low capital requirements. The project was successfully exploited for thorium in an underground operation by Anglo American between 1952 and 1963. The Steenkampskraal mine holds the full spectrum of rare earths, [8] MINING MIRROR MAY 2017 including high-value neodymium used in the manufacture of magnets, computers, and hard drives. Typically, a 3MW wind turbine uses about 500kg of neodymium and 100kg of praseodymium in the magnets for its motors. Lanthanum is used in NimH hybrid batteries with cerium and there is potential demand for over 100 million kilograms of rare earth metals for hybrid and fully electric vehicles over the next few years. A typical hybrid car uses 10kg of rare earth metals. Hybrid electric motors use dysprosium and terbium, and their component sensors use yttrium. Total rare earth oxide deposits found around the world have an average in situ grade of between 1% and 3%. When deposits are mined, the grade is even less because the in situ mineralised material is mixed with material (waste rock) that has little or no value (the mining cut). Hard rock deposits, such as the monazite deposit at Steenkampskraal, generally have higher grades compared to beach sand deposits.  Rare earths in India are generally contained in sand deposits, while in China they are found mainly in dolomite marble, which is also associated with iron ore. When rare earths are contained in sand deposits, the extraction process is more difficult and costly when compared to rare earths deposits that are associated with mo