Name of the Project
Mackay sulphate of potash (SoP) project.

Location
The projectis located 785 km south of the Port of Wyndham, in Western Australia.

Client
Agrimin Limited.

Project Description
A prefeasibility study (PFS) has demonstrated the potential for the Mackay SoP project to become a long-life and low-cost supplier of SoP.

The mine plan predicts an average annual brine extraction rate of 66.3-million cubic metres, with an average SoP grade of 8 kg/m3 over an initial 20-year period. 

This equates to the extraction of 531 000 t/y of SoP and is based entirely on the extraction of the indicated mineral resource (specific yield and total porosity) within the modelled depth of extraction of 3 m below ground.

The production of SoP will begin with the extraction of potassium-rich brine using an on-lake trench system. 

The PFS trench network and feed channel is planned to have a length of 546 km and an average depth of 4.5 m, resulting in 8.50-million cubic metres of excavated material. 

The depth of the trenches will vary to allow for sufficient volume and gradient so that the brine can flow naturally along the trench network southwards to the feed channel. Brine will be transferred along the channel to the solar evaporation ponds with the assistance of two pumping stations.

The mine is expected to have an initial operating life of 20 years. Potential exists to increase production rates and/or extend the operational life of the project.

Potential Job Creation
The project is expected to employ a workforce of about 200 people during operations.

Net Present Value/Internal Rate of Return
The project has a post-tax net present value, at an 8% discount rate, of $453.2-million, and an internal rate of return of 20%, with a post-tax payback of 4.2 years.

Value
Capital costs, including $53-million in contingency, have been estimated at $409-million.

Duration
The project’s construction and commissioning is expected to take 36 months. A production ramp-up of 70% of production is expected in the first 12 months of operations before reaching the full production target of
426 000 t/y.

Latest Developments
A definitive feasibility study (DFS) on the project is expected to be completed in mid-2019.

The DFS will incorporate the results of the Agrimin’s pilot evaporation ponds and the processing of a bulk sample of harvested salt to produce samples of high-quality SoP for further customer testing and validation. The pilot ponds have been constructed on Lake Mackay and are in the precommissioning phase. Product samples are expected to be available for customers in the fourth quarter of 2018.

The DFS will form the basis of the company’s finalising financing for the construction of the project and making a final investment decision.

In parallel to the DFS, offtake discussions are planned to continue to commit most of the project’s planned production under binding offtake agreements.

Key Contracts and Suppliers
Advisian (lead engineer and study manager for the PFS), Hydrominex Geoscience and H&S Consultants (mineral resource), Knight Piésold (hydrogeological studies and civil and geotechnical work), Global Potash Solutions (process design), Saskatchewan Research Council (evaporation and process testwork), Qube Bulk (product logistics) and 360 Environmental and Strategen Environmental (environmental work).

On Budget and on Time?
Too early to state.

Contact Details for Project Information
Agrimin Limited, tel +61 8 9389 5363 or email admin@agrimin.com.au.