Speaking at the Critical Minerals Africa Conference in Cape Town, Graham Soden – a director, CEO and mine manager of Steenkampskraal Monazite Mine – outlined the mine’s planned development strategy to December 2027 to bring the mine into production.
The strategy covers producing monazite concentrate with the construction of a monazite concentration plant, followed by the construction of a cracking plant to produce mixed rare earth (RE) carbonate and thorium. This will be followed by the construction of a separation plant to produce mixed RE oxides.
To date, Soden said about R1 billion has been invested in the mine’s infrastructure. “The first phase of three phases will involve the mobilisation of the mining and processing plant and equipment to the site, refurbishment of the decline and shaft area, and re-equipping the headgear and infrastructure.
“Material and loose ore from underground will be reclaimed, followed by the construction of the monazite concentration plant and commencement of underground mining. The first monazite concentrate is expected to be produced by December 2024,” he added.
The second phase will involve increased mining volumes and monazite concentrate production and all metallurgical test work, design and planning for the construction, and commissioning of a monazite cracking plant. This will produce mixed RE carbonate and thorium. In this phase, the design and planning of an RE separation plant will also be undertaken.
In phase three, the construction and commissioning of the separation plant will be completed to produce mixed RE oxides. The period January 2026 to December 2026 will see the cracking plant commissioning and initial production of mixed RE carbonate and thorium. The period January 2027 onward will see the steady state production of monazite concentrate to the cracking plant with the production of mixed RE carbonate and thorium, with plans to produce individual RE oxides.
To finance the project, from August 2023 to January 2024 the mine will raise US$2 million in capital. This will cover planning, design and metallurgical test work for phases 2 and 3. From January 2024 to July 2024, US$15 million to US$20 million will be raised for working capital, project mobilisation and ongoing metallurgical test work for phases 2 and 3.
The period August 2024 to December 2024 will see the commissioning of phase 1, the first production of monazite concentrate and ongoing phase 2 and 3 metallurgical test work.
Between January 2025 and December 2025, there will be a further capital raise of US$15m to US$20m for the steady state production of monazite concentrate, and cracking plant design and construction. The period January 2026 to December 2026 will see an increase in run of mine (RoM) production, the cracking plant commissioning and associated increase in monazite concentrate production to the cracking plant, and the initial production of mixed RE carbonate and thorium.
From January 2027 onward, an additional US$15m to US$20m capital will be raised. This will be for the steady state production of monazite concentrate, increased RoM production and monazite concentrate for the cracking plant and the production of mixed RE carbonate and thorium. Following this, individual RE oxides are planned to be produced.
Soden said the market for rare earth elements is projected to triple by 2035, according to an Adamas Intelligence report, with a compound annual growth rate (CAGR) increase of 8.3% in total market demand. RE prices are expected to have a CAGR increase of between 3.2% and 3.7%. The market value of RE is projected to be about US$46.2 billion by 2035 globally.
“The problem the industry is currently experiencing is that RE prices are dependent on Chinese national policies. China can control RE prices simply by adjusting the supply. China exercises lower levels of environmental and legislative control and, as a result, 40% to 50% of RE production is grey or illegal. Currently, 80% to 90% of rare earth elements come from China, which poses significant geopolitical and environmental risks.”
He said the Steenkampskraal mine deposit is rich in neodymium, praseodymium (NdPr), dysprosium, terbium and other RE minerals. The primary elements at the mine are neodymium – 56.59%, dysprosium – 14.19%, praseodymium – 12.43%, terbium – 9.62%, gadolinium – 2.12% and cerium – 1.95%.
Soden added that Anglo American developed the mine to an average depth below surface of 100m along a 400m strike, with three mining levels and access through a 140m decline and 28m vertical shaft. Much of the reef drives and stopes have been left unmined. “Ground conditions are geotechnically competent, enabling rapid recommissioning of mining operations.
“Large volumes of blasted ore have been left underground, ready to be reclaimed. The orebody varies in thickness and dip, and will be mined conventionally by employing a combination of mining methods. The planned optimised techno-economic development plan will be ongoing to further improve efficiencies. Due to existing face availability, minimum development will be required initially.”
He said a minimum of 5 000 tpa of monazite concentrate will be produced in the first phase. A proven conventional gravity separation and flotation processing plant will be used based on the successful Anglo American process in 1952.
Steenkapmskraal is fully licensed to commence mining and to produce monazite concentrate, mixed rare earth carbonate and thorium, and separated RE oxides (Phases 1, 2 and 3).
Base case revenue
Net present value (NPV) assumptions are based on the production of 5 000 tonnes of monazite concentrate per annum at an average price of US$6 000 per tonne. In the first phase, the value of monazite concentrate will generate a NPV greater than US$200 million. In Phase 2, the value of mixed rare earth carbonate excluding thorium will be US$5 200/tonne with an expected NPV greater than US$300 million. Phase 3 expected revenue for separated REs based on an average price of US$37 000/tonne per annum will generate a NPV greater than US$620 million.
Soden said the mine will be 100% dependent on renewable energy within two years of commissioning. “As an underground mine, it will have negligible surface impact, with all environmental approvals in place with ongoing rehabilitation of the historical footprint.
“Rare earths are a critical contributor to the low-carbon energy industry, while thorium is a clean energy fuel of the future and could be used in molten salt reactors. The mine’s ongoing social and labour plan projects are geared to leaving a lasting legacy, with a broad-based employee equity partnership of 26% through the company’s BBBEE structure, and management is committed to transparent and sustainable governance principles.”
