Tharisa Minerals is 100% owned by Tharisa plc and is uniquely positioned as a significant co-producer of both PGMs and chrome concentrates. Tharisa Minerals’ core asset is the Tharisa Mine, situated on South Africa’s western limb of the Bushveld Complex and home to more than 70% of the world’s platinum and chrome resources.
Tharisa Minerals mines and processes five MG chromitite layers. The mined reef is processed through innovative engineering at two separate plants, extracting both PGMs and chrome concentrates. This combined co-product output reduces unit costs and positions Tharisa Minerals in the lower cost quartile of operating costs in South Africa for both PGMs and chrome concentrates.
Tharisa Minerals’ low unit costs, operating flexibility and multiple polymetallic products have ensured that it is well placed to manage commodity price and exchange rate volatility.
Its dual revenue streams provide a natural hedge against different commodity cycles with the products used in various applications.
The Tharisa Mine remains a world-class, long-life asset that underpins our business and will continue to provide a sustainable, low-cost platform for multiple generations to come.
Tharisa Minerals holds a Mining Right over 5 475 ha of land near the town of Rustenburg in the North West province of South Africa. The Mining Right was granted on 19 September 2008 for an initial period of 30 years, providing access to MG chromitite layers, which outcrop with a strike length of approximately 5 km.
The open pit is divided into the east, west and far west pits and extracts reef from five MG chromitite layers.
Tharisa Minerals’ two separate processing plants are designed to treat the MG chromitite layers of the Bushveld Complex. The smaller volume Genesis Plant was commissioned in August 2011, with the PGM circuit in December 2011. The larger-volume Voyager Plant was commissioned in December 2012. Both plants operate above designed nameplate capacity following various upgrades. The plants have a similar process flow that includes crushing and grinding, primary removal of chrome concentrate by spirals, followed by PGM flotation from the chrome tails and a second spiral recovery of chrome from PGM tails
Operating in parallel, the separate plants provide processing flexibility and production stability by allowing one plant to be shut down without hampering the production of the other. The modular design of the processing circuits will enable sections of the plant to be stopped without affecting the rest of the operation (i.e. a crushing circuit can be stopped independently of the milling, spiral and flotation circuits).
The PGMs in the MG ore mined by Tharisa Minerals occur in the silicates. They are not associated with chromite, thus enabling the process to extract chrome before PGMs without sacrificing PGM recovery.
This lowers the chrome content in the PGM circuit, resulting in much lower chrome content in the PGM concentrate compared to typical UG2 operations. Base metal content in the MGs is also significantly lower than in Merensky and UG2 ores, resulting in a low matte pull during smelting, reducing base metal refining requirements.
Using off-the-shelf technology, the Genesis and Voyager processing plants are uniquely engineered to produce both PGM and chrome concentrates. This innovative approach to production has made Tharisa a world-class PGM and chrome concentrate co-producer.
A third high-volume plant, the Vulcan Plant, was commissioned in FY2021. The plant, which processes live tailings produced by the Voyager and Genesis plants, ensures further beneficiation of the Company’s chrome production at the Tharisa Mine while reducing the unit output of carbon emissions.
The Vulcan Plant is the first large-scale plant to produce chrome concentrates from ultra-fines, consolidating Tharisa’s position as a key chrome producer. The concept of Vulcan was developed entirely in‑house by the research and development (’R&D’) team to extract the ultra-fine chrome from tailings.
Specialty chrome recovery circuits are integrated into the feed circuit of the Genesis Plant, known as the Challenger Plant. The Challenger Plant, owned by fellow subsidiary Arxo Metals, was commissioned in July 2013 and produces chemical and foundry grade chrome concentrates, significantly adding to the revenue diversification strategy of Tharisa.
PGM concentrate: PGM concentrate is produced from both processing facilities. The concentrate produced from the Voyager Plant is a higher grade than the concentrate from the Genesis Plant, due to the different chromitite reefs treated by the respective plants. The major component of the PGMs is platinum, followed by palladium and rhodium, as measured by volume.
Platinum
Palladium
Rhodium
| Average market price | FY2023 US$/oz |
FY2022 US$/oz |
Change % |
|---|---|---|---|
| Platinum | 981 | 968 | 1.3 |
| Palladium | 1 594 |
2 107 |
(24.3) |
| Rhodium | 8 992 | 14 962 | (39.9) |
| Average chrome price | FY2023 US$/oz |
FY2022 US$/oz |
Change % |
|---|---|---|---|
| 42% metallurgical grade | 263 | 209 | 25.8 |
The typical metallurgical grade produced by Tharisa is 40.0% to a 42.0% chrome (as Cr2O3) with the silica (SiO2) lower than 5.0%.
The typical chemical-grade produced by Tharisa is 44.0% to 46.0% Cr2O3 with the SiO2 lower than 1.0%. This is a higher-value chromite product than the metallurgical grade chrome concentrate.
The typical foundry grade produced by Tharisa is 45.0% to 46.0% Cr2O3 with the SiO2 lower than 1.0%. The American Foundryman Society Grain Fineness number (AFS number) is managed between 45 and 50. As with the chemical-grade chromite, this is a higher-value chrome concentrate than the metallurgical grade chrome concentrate.
