Name and Location
Browns Range rare earths project, Australia.

Client
Northern Minerals.

Project Description
A new business plan to support the pathway to production at the project has separated its development into three stages.

Stage 1 involves the construction of a pilot plant operation. The three-year operation will comprise a beneficiation and hydrometallurgical process to produce 49 000 kg/y of dysprosium, in 590 000 kg of total rare-earth oxides (TREO) contained in a mixed rare-earth carbonate (REC).

The mining operation will consist of an openpit mining campaign over five months from relatively shallow pits at the Wolverine, Gambit West, Gambit Central and Gambit East deposits. A total of 172 080 t of mineralised material at 1.19% TREO, containing 2.05-million kilograms TREO, will be mined and stockpiled, ready to be fed to the pilot plant. A 1.19% TREO grade is achieved as a result of higher-grade ore near the surface of the deposits to be mined and will have minimal impact on the ore grade when the project is developed at full scale.

Stage 1 involves the pilot plant’s processing 60 000 t/y of ore at 1.19% TREO through the beneficiation plant, and 3 200 t/y of xenotime concentrate at 20% TREO through the hydrometallurgical process. The processes will be modularised and containerised for the pilot plant where possible to facilitate a compressed site-construction period and allow for the pilot plant to be transported to other projects for testwork if required.

Stage 2 involves developing the project to bankable feasibility study (BFS) level, with the inclusion of the results aimed at reducing mining costs, boosting production, producing a premium product and increasing the ore reserve.

The results of testwork undertaken during the operation of the pilot plant will contribute to the completion of the BFS during the second stage During Stage 3, Northern Minerals intends to build the full-scale project, based on the definitive feasibility study (DFS) completed in March 2015 and the successful outcomes of the previous stages.

In line with the DFS, the full-scale operation will use a combination of openpit and underground mining methods to extract 585 000 t/y at 0.66% TREO, which will be treated with a beneficiation and hydrometallurgical plant.

The beneficiation plant will have the capacity to treat up to 585 000 t of ore to produce an estimated 16 700 t/y of mineral concentrate at a grade of 20% TREO.

The hydrometallurgical process will further treat the 16 700 t/y of mineral concentrate to produce 279 000 kg/y of dysprosium, contained within 3.1-million kilograms of TREO, prior to yttrium rejection.

The inclusion of the Stage 2 study component is expected to deliver a higher output at lower cost to that of the DFS and, with the inclusion of the additional process components to reject the majority of the yttrium, the project will produce a premium, high-purity mixed REC product.

Net Present Value/Internal Rate of Return
Not stated.

Value
Not stated.

Duration
Construction of Stage 1 is estimated to take nine months once funding is in place.

Latest Developments
The plan to progress Stage 1 to development is well under way.

Discussions are advancing with several potential offtake partners and strategic investors with regard to product offtake and funding.

Northern Minerals has also engaged with government regulators to use existing approvals for Stage 1. It is also working through cost development and project scheduling with the assistance of an engineering firm and mining contractor.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Northern Minerals, tel +61 8 9481 2344, fax +61 8 9481 5929 or email info@northernminerals.com.au.