A scoping study for Ark Mines’ Sandy Mitchell rare earths (REE) project has labelled the asset as a “low-cost, scalable world-class REE development”.
Sandy Mitchell is located in far north Queensland. It has an exploration target of 1.3–1.5 billion tonnes at 1286 to 1903 parts per million (ppm) monazite equivalent and a measured mineral resource estimate (MRE) of 71.8 million tonnes (Mt) at 1733ppm monazite equivalent, using a lower cut-off grade of 700ppm monazite equivalent.
The scoping study was completed to determine the viability of Sandy Mitchell’s surface-free dig strip mining and synchronous gravity beneficiation to produce a monazite concentrate, which contains REE.
The study found that Sandy Mitchell has a three-to-four-year life of mine, based on the project’s MRE overall tonnage, and an average throughput of 20–22Mt per annum, comprising monazite, xenotime, zircon, rutile and garnet.
Other findings from the study include:
- $120–150 million in total capital expenditure
- $120–130 million in average revenue per annum
- Post-tax capital payback of approximately 3–4 years from first rare earth mineral concentrate production
- easily accessible deposits, resulting in an extremely low strip ratio
- low environmental impact as sands are near-surface and no overburden removal, underground development, drilling and blasting is involved.
“The scoping study has indicated that this project scenario is economically robust,” Ark Mines said.
“However, the study is based on base case metallurgical recoveries which have highlighted areas for significant process improvement. Further test work and optimisation will likely increase the recoveries and grade of the concentrates.”
The Ark Mines board has unanimously recommended advancing Sandy Mitchell to the next phase of development, starting with a pre-feasibility study that is due for completion in 2025.
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