Overview
| Stage | Permitting |
| Mine Type | Surface |
| Commodities |
- Sulfate of potash (SOP)
- Potassium
|
| Mining Method |
|
| Mine Life | 40 years (as of Jan 1, 2020) |
The 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. |
Source:
p. 39
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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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 ........
Summary:
The mine plan has an average brine extraction volume of 86 gigalitres per annum (“GL/a”) with an average potassium grade of 2,820 milligrams per litre (“mg/L”). Throughout the life of mine, extraction and recharge processes are expected to gradually dilute the potassium grade from 3,280 to 2,560mg/L. This grade dilution will be offset by increasing the annual brine extraction rate from 74 to 94GL/a in order to maintain a constant feed rate of SOP into the evaporation ponds.
The mine plan is predicted to deliver a constant brine feed containing 540ktpa of SOP into the evaporation ponds for the 40 year life, totalling the extraction of 21.6Mt of SOP. The Ore Reserve is based on the 20.0Mt of SOP that is predicted to be extracted from the Measured and Indicated Mineral Resource categories under the mine plan. In addition, 1.6Mt of SOP will be extracted from the Inferred Mineral Resource category. Accordingly, the DFS mine plan and production target contains 93% Ore Reserve and 7% Inferred Mineral Resource
Between August 2017 and July 2019, Agrimin’s DFS fieldwork involved the excavation of 22 pilot trenches which were geographically spread across Lake Mackay.
The trench network has been optimised to be laterally extensive and shallow in order to minimise the volume of material excavated and allow the use of the most productive excavation equipment.
The trench network has been split into 17 brine mining units (“BMU”) which represent ........
Flow Sheet:
Summary:
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Projected Production:
| Commodity | Units | Avg. Annual | LOM |
|
Sulfate of potash (SOP)
|
kt
| 450 | 21,600 |
All production numbers are expressed as crystals.
Operational Metrics:
| Metrics | |
|
Annual mining rate
| 86 M cu.m * |
|
Annual processing capacity
| 3 Mt * |
* According to 2020 study.
Reserves at January 20, 2020:
Brine grades within lakebed lithologies outside of islands were applied a bottom cut of 1,500mg/L. Grades less that this 1,500mg/L were identified as anomalous, local and not representative of natural conditions.
No cut-off grades have been applied due to the homogeneity of the chemistry data and the proposed extraction method of brine from trenches.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
602 M cu.m
|
Sulfate of potash (SOP)
|
|
3.7 Mt
|
|
Proven
|
602 M cu.m
|
Potassium
|
2797 mg/L
|
|
|
Probable
|
2,592 M cu.m
|
Sulfate of potash (SOP)
|
|
16.3 Mt
|
|
Probable
|
2,592 M cu.m
|
Potassium
|
2819 mg/L
|
|
|
Proven & Probable
|
3,195 M cu.m
|
Sulfate of potash (SOP)
|
|
20 Mt
|
|
Proven & Probable
|
3,195 M cu.m
|
Potassium
|
2815 mg/L
|
|
|
Measured
|
4,621 M cu.m
|
Sulfate of potash (SOP)
|
|
3.9 Mt
|
|
Measured
|
4,621 M cu.m
|
Potassium
|
3473 mg/L
|
|
|
Indicated
|
43,784 M cu.m
|
Sulfate of potash (SOP)
|
|
19.5 Mt
|
|
Indicated
|
43,784 M cu.m
|
Potassium
|
3527 mg/L
|
|
|
Measured & Indicated
|
48,405 M cu.m
|
Sulfate of potash (SOP)
|
|
23.5 Mt
|
|
Measured & Indicated
|
48,405 M cu.m
|
Potassium
|
3509 mg/L
|
|
|
Inferred
|
304,641 M cu.m
|
Sulfate of potash (SOP)
|
|
99.9 Mt
|
|
Inferred
|
304,641 M cu.m
|
Potassium
|
3232 mg/L
|
|
|
Total Resource
|
353,046 M cu.m
|
Sulfate of potash (SOP)
|
|
123.4 Mt
|
|
Total Resource
|
353,046 M cu.m
|
Potassium
|
3285 mg/L
|
|
Source:
Corporate Filings & Presentations:
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