Name of the Project
Ngualla rare earths project.

Location
Tanzania.

Client 
Peak Resources, Appian Natural Resources Fund and the International Finance Corporation.

Project Description
The Ngualla project has been confirmed as having the potential to become one of the lowest-cost and highest-quality rare earths projects worldwide. The project has a mineral ore reserve of 18.5-million tonnes grading 4.8% rare-earth oxide (REO).

An optimisation study completed on the project in August envisages a mine life of 26 years, compared with 31 years in the bankable feasibility study (BFS) completed in April. This is based on the weathered Bastnaesite zone mineralisation, which comprises only 22% of the total Ngualla mineral resource estimate at a 1% REO lower-grade cutoff. Ore mill feed has increased from 624 000 t/y in the BFS to 711 000 t/y in the optimisation study, while processed mineral concentrate has been estimated at 32 700 t/y, compared with 28 300 t/y in the BFS. Final products from the project are planned to be: 
• 2 810 t/y of neodymium and praseodymium rare-earth oxide (2N min 75% Nd₂O₃), 
• 625 t/y of mixed samarium/europiumgadolinium and mixed heavy rare-earth carbonate, and
• 3 475 t/y of cerium carbonate and 7 995 t/y of lanthanum carbonate. 

A capacity analysis of the multistage processing facility at Ngualla in the optimisation study has identified the rare earths flotation stage as the primary bottleneck in the circuit as designed for the BFS. The capacity of this stage of the circuit is a function of the size and number of the flotation cells and the residence time that the ore must stay in each cell to achieve the desired recovery.

A reduced residence time thus means the amount of ore passing through the circuit can be increased without changing the size or number of cells. 

Removing the process bottleneck from the rare earths flotation cells shifts the capacity constraint to the ball mill. By maximising the throughput of the existing ball mill at an additional capital cost of $4-million and a slightly accelerated BFS mining schedule, the average mill feed and corresponding concentrate production can be increased by an estimated 16% a year. 

Analysis of the proposed refinery expansion in Tees Valley, in the UK, has identified that the capacity constraints of increasing the throughput to take the additional processed product from Ngualla are the three solid liquid separation processes. 

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project’s post-tax and royalties net present value, at an 8% discount rate, has decreased from $633-million in the BFS to $612-million in the process optimisation study. The internal rate of return has increased from 21% to 22%.

Payback has been estimated at five years.

Value
The capital cost of the project has increased from $356-million in the BFS to $365-million in the optimisation study for Ngualla and the Tees Valley refinery.

Duration
Not stated.

Latest Developments
Peak Resources will raise A$6.3-million through a share placement to fund its Ngualla project costs.

The company will issue 86-million shares in the first tranche of its share placement, priced at 4c a share, to raise an initial A$3.44-million. The first tranche placement will be made under Peak’s existing capacity.

The second tranche of 71.5-million shares, which will raise an additional A$2.86-million, will be subject to shareholder approval.

Funds from the placement will be used for Peak’s share of the Ngualla project costs, and the Teesside refinery, including permitting and licence applications, as well as the costs associated with marketing and negotiating offtake and project financing. It will also be used to retire some debt and cover general operating expenses.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Peak Resources, tel +61 8 9200 5360, fax +61 8 9226 383 or email info@peakresources.com.au.