Robe Mesa Iron Ore Project, Australia

The Robe Mesa Iron Ore Project in Western Australia is being developed by multi-commodity exploration and development company CRZ Resources.

The project forms a part of the larger Yarraloola Iron Ore Project.

The iron ore project’s pre-feasibility study was completed in December 2020, followed by the release of the Definitive Feasibility Study (DFS) in October 2023.

CZR aims to take the final investment decision on Robe Mesa in the second quarter of 2024, and start iron ore exports in first half of 2025.

The iron ore project’s mine life is estimated to be eight years, with an Earnings Before Interest, Taxes, Depreciation, and Amortization (EBITDA) of A$824m ($538m).

Initially, Robe Mesa will produce at the rate of 3.5 million tonnes per annum (Mtpa) for the first four years and then ramp up production to 5Mtpa.

Robe Mesa Iron Ore Project Location

The Robe Mesa Iron Ore Project is located in the West Pilbara, Western Australia. The site is within the Shire of Ashburton, around 175km by road from the town of Onslow.

The project forms a part of the Robe Valley channel iron deposits (CID) and is situated immediately north of Rio Tinto’s Mesa F iron ore project.

The project mine site and processing area have been covered by mining lease application M08/533.

Background Details

In 2012, CZR bought Zanthus Resources and established a joint venture with Mark Creasy`s ZanF. This included the Yarraloola project and Robe Mesa (Yarraloola JV).

CZR owned 85% interest in the Yarraloola JV via Zanthus, while the remaining 15% was with ZanF.

CZR began extensive exploration at Robe Mesa between 2014-15 and started working on Robe Mesa DFS in 2021.

In December 2022, CZR formed the Port of Ashburton Consortium (PAC), a joint venture between CSL Australia (CSL), Strike Resources (SRK) and CZR.

The JV to assess and secure approvals for a 5 million tonnes per annum (Mtpa) iron ore export facility from the Port of Ashburton (POA Export Facility). CZR owns 50% of PAC JV, while SRK and CSL hold 25% interest each.

Western Australia’s Department of Mines, Industry Regulation and Safety (DMIRS) granted Mining Licences M08/533 (Robe Mesa Deposit) and M08/519 (P529 Deposit) to CZR in January 2023.

In January 2024, CZR entered into a binding share sale agreement to sell its 85% interest in Robe Mesa to Miracle Iron Resources for A$102m ($67m).

Geology and Mineralisation

The Robe Mesa orebody is classified as a Channel Iron Deposit (CID), similar to several operating iron-ore mines and deposits in the West Pilbara region.

As the deposits were formed through erosion and transport and reconsolidation processes, they are categorised as ‘secondary’.

Robe Mesa is part of the tertiary-aged channel Robe River paleochannel. The property’s iron-ore is in the centre of the Robe palaeo-channel which contains a well-characterised and well-known pisolitic ore-type.

The ore contains low phosphorous and can be upgraded by driving off, or calcining, the volatile components.

Robe Mesa Project Reserves

The iron ore project is estimated to contain ore reserves of 33.4 million tonnes (Mt) at 55.0% iron (Fe) (61.6% Fe calcined).

According to the DFS, the reserve estimate includes 26.4Mt of high-grade product (Robe Mesa Fines) and 7.0 Mt of a low-grade product (Robe Mesa LG Fines).

Total Mineral Resource Estimate is 45.2Mt at 56% Fe (62.7% Fe calcined).

Mining Method

The Robe Mesa Project will be mined using open-pit mining methods and deploying conventional trucks and excavators.

The orebody comprises two horizontal layers (upper and lower), which will be mined selectively on 4m benches.

A very low life of mine strip ratio of 0.6:1 (waste: ore) will reduce complexities and mining costs.

Robe Mesa will utilise 120-tonne excavators and haulage with 90-tonne trucks for loading.

Ore will be hauled to a central run of mine (ROM) pad and fed into the ROM bin using front-end loaders.

There will be no external waste dumps with waste backfilled into the open pit, reducing the environmental impact.

Mining activity will cease in the eighth year, while processing will continue for additional nine months.

Robe Mesa Ore Processing

The iron ore project is scheduled to process high-grade at a rate of 3.5Mtpa for the first four years, while low-grade will be stockpiled. Processing throughput will be increased to 5Mtpa after the fourth year, with the inclusion of the low-grade ore.

The ROM pad is planned to be constructed off the mesa, feeding a crush and screen processing plant.

The ROM ore will be deposited onto various ROM fingers, which will have distinct grade characteristics.

Ore will pass from active ROM finders with a front-end loader and tip to the ROM feed bin to meet target blending criteria.

An apron feeder will handle the feed from the ROM bin to remove material already suitable for the secondary crusher. Grizzly oversize will be fed to the jaw crusher.

The jaw crusher product, grizzly undersize, and apron feeder dribble will combine and pass through a scalper screen and the oversize will be transferred to the secondary crusher.

The undersize material will be sent directly to the product conveyor, while the oversize will be transferred to the tertiary crushers and then circulated to the classification screen.

The tertiary crusher product continues to circulate through the circuit until it achieves necessary size to pass through the classification screen to the product conveyor. The product conveyor, equipped with a weightometer, can measure the tonnages of final product and processing contractor invoicing.

Final product is stacked into one of three stockpiles- Live Stockpile; Preliminary Stockpile; and Released Stockpile.

The 5mtpa export facility at the Port of Ashburton (POA) will be used to ship the product to customers.

Robe Mesa Infrastructure

A 38km private haul road will link Robe Mesa mining operations with the North West Coastal Highway, mine operations centre and accommodation.

Power required for project operations will be generated using diesel power generators with a total site capacity of 5MW.

Water will be pumped from the Eastern bore field pipeline into a raw water pond and will be distributed to storage tanks at the mine operations centre and processing plant locations.

Contractors Involved

CZR engaged several industry specialists for the Robe Mesa DFS including AQ2; Bamford Consulting Ecologists; Bureau Veritas; ERM; George Boucher Consulting; Graeme Campbell and Associates; McNally; and Shawmac among others.

Snowden Optiro was contracted by CZR to complete an ore reserve estimate for the Robe Mesa Project.

Shawmac carried out mine operations centre infrastructure and drainage design.

ERM (electrical engineering consultants) prepared the MOC electrical design and distribution report for the project.