The Tharisa Mine is situated in the Bushveld Complex, which contains more than 70% of the world's known PGM resources and 75% of the world's known chrome resources. Mining at the Tharisa Mine involves the extraction of ore from the Middle Group chromitite reefs, which comprise four main layers of mineable ore of differing PGM and chrome content. Tharisa Mine's total chrome resources of approximately 900Mt of contained chrome make it the largest single chrome mineral resource deposit in the world.
The chromitite reefs outcrop at the surface of the land along a wide strike of approximately 5km, which has enabled commercial open pit mining. The chromitite reefs dip away at a shallow angle of approximately 12-15 degrees, which allows open pit mining for a life of mine of at least 17 years, potentially longer with an increase of the highwall to 200m, with the potential for long-term underground mining thereafter. Open pit mining has numerous benefits when compared to underground mining, including shorter time frames for mine infrastructure construction, higher production volumes leading to larger scale operations, lower capital expenditure requirements and production cost structure and significantly reduced operational hazards. Additionally, open pit mining allows for full extraction of the Tharisa Mine's mineral resource base as compared to underground mining, in which significant quantities of ore must remain in the ground so as to provide support for the underground infrastructure.
Generalised geological map of the Bushveld Complex, showing Tharisa Mine
