Mining Intelligence and News
Australia

Mackay Project

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Categories

Overview

Mine TypeSurface
StagePermitting
Commodities
  • Sulfate of potash (SOP)
  • Potassium
Mining Method
  • Brine mining
Mine Life... Lock
SnapshotThe Project remains on track to become the world’s largest and lowest cost seaborne supplier of SOP fertiliser at a time that the world urgently needs new supply.

The Environmental Review Document for the Mackay Potash Project was released by the Western Australian Environmental Protection Authority for public comment in May 2022 and we are now currently preparing responses to those comments. The Environmental Impact Assessment remains on the critical path to the Project’s development and based on statutory guidelines the indicative timeline for approval is early 2023.

Owners

SourceSource
CompanyInterestOwnership
Agrimin Ltd. 100 % Indirect
The DFS for the project is based on nine granted Exploration Licences in Western Australia, currently held by Agrimin under its 100% owned subsidiary, Agrimin Potash Pty Ltd.

Contractors

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Deposit type

  • Brine
  • Sedimentary

Summary:

Lake Mackay’s hydrogeological setting and favourable brine chemistry provide important attributes that support the development of a globally significant SOP operation. Lake Mackay hosts the largest SOP deposit in Australia and covers an area of approximately 3,500km2.

Lake Mackay is a brine-hosted potash deposit in a closed basin, salt lake setting. The Mineral Resource is based on the dimensions of the lakebed sediments, the variations in porosity (void space) and the potassium grade within the groundwater.

The drainable porosity (or specific yield) Mineral Resource contains 123Mt of SOP to a maximum depth of 211m. This drainable porosity Mineral Resource represents the static free-draining portion of the total porosity Mineral Resource prior to extraction.

There is a high level of confidence in the geological model for the project. The geology is simple, with brine-hosted in flat lying, relatively uniform, lakebed sediments.

Geology has been used to separate the deposit into different layers for the resource estimate. The upper sandy layer is more porous, beneath which there is a less porous unit overlying the lower clays that are again less porous, prior to reaching the coarser LZ3 sediments.

Within the upper zone (UZ) the lakebed sediments are further separated into top and bottom sub- horizons labelled as UZT and UZB.

The lower zone (LZ) sediments are separated into three sub-horizons labelled as LZ1, LZ2 and LZ3.

These sub-horizon divisions were introduced on account of subtle changes in lithostratigraphy with increasing depth from surface.

Lake sediments are saturated in brine below 0.5m depth from surface which represents the average brine level during the dry season across the lakebed.

A basement surface has been identified from drilling and geophysics, limiting the vertical extent of the lake sediments above. Lakebed sediments extend to a drilling depth of 150m where a basal paleochannel unit has been identified.

The paleochannel is incised into the basement to a maximum depth of 211m. Beyond the extents of the paleochannel the basement surface rises gently towards the east to a depth of between 11m and 25m below surface in the shallowest parts.

Islands are situated on the lakebed surface. These low relief islands (elevation from 362m to 370m) are interpreted to be aeolian in origin and are not included as part of the Mineral Resource estimate.

Sedimentary processes affect the continuity of geology, whereas the concentration of potassium and other elements in the brine is related to water inflows, evaporation and brine evolution in the salt lake.

The top of the resource is defined by the surface of the lakebed and extends below islands at the same elevation between 361m and 362m (AMSL). The base of the resource is defined by the basements surface that varies in depth from 211m maximum to between 11m and 25m below lakebed surface. The resource remains open laterally outside of the Company’s tenements off the lake (where it is covered by sand dunes) and at depth.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityUnitsAvg. AnnualLOM
Sulfate of potash (SOP) kt 45021,600
All production numbers are expressed as crystals.

Operational metrics

Metrics
Annual mining rate  ....  Subscribe
Annual processing capacity  ....  Subscribe
* According to 2020 study.

Production Costs

CommodityUnitsAverage
Site cash costs (produced) Sulfate of potash (SOP) USD  ....  Subscribe
Cash costs Sulfate of potash (SOP) USD  ....  Subscribe
All-in sustaining costs (AISC) Sulfate of potash (SOP) USD  ....  Subscribe
Assumed price Sulfate of potash (SOP) USD  ....  Subscribe
* According to 2020 study / presentation.

Project Costs

MetricsUnitsLOM Total
Pre-Production capital costs $M USD  ......  Subscribe
Operating margin, %  ......  Subscribe
EBITDA (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 8% $M USD  ......  Subscribe
After-tax NPV @ 8% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Dec 21, 2023
....................... Subscription required ....................... Subscription required Subscription required Dec 21, 2023
....................... Subscription required ....................... Subscription required Subscription required Dec 21, 2023

Total WorkforceYear
...... Subscription required 2020

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