The Cloudbreak, Christmas Creek and Kutayi deposits lie within the Chichester Ranges, in northern Western Australia. Iron mineralisation is hosted by the Nammuldi Member which is the lowest member of the late Archaean aged Marra Mamba Iron Formation (MMIF). The Nammuldi Member is characterised by extensive, thick and podded iron rich bands, separated by equally extensive units of siliceous and carbonate rich chert and shale. The Nammuldi Member in the Chichester Range is interpreted to be up to 60 metres in true thickness. Underlying the Nammuldi Member rocks are black shales and volcanic rocks belonging to the Jeerinah Formation. Extended periods of tectonic activity have variably folded and faulted these rocks, together with weak metamorphism. Subsequent erosion and hardcapping or lateritic processes have altered these rocks, and present outcrop of Nammuldi Member represents a ridge of lowlying hills (relief up to 30 metres) throughout the prospect areas. These ridges are recognised as the Chichester Ranges.

Drilling within the prospects has proved that the Nammuldi target horizon extends below cover away from the hills. In these regions (recognised mineralisation has been intersected more than 6 kilometres from the outcrop) the target iron formation can be overlain by Tertiary age colluvium and alluvium (younger than 65 Million years). This colluvium can contain both cemented and un- cemented detrital products of iron enriched material, BIF, chert and shale wit ........

The mining model is based on strip mining. Mining at Cloudbreak will continue to be carried out as open pit strip mining. The pits are developed progressively, where a starter pit is opened (with overburden from the starter pit placed in a small overburden stockpile). As the mining face progresses, the open pit is progressively backfilled and rehabilitated. The majority of the ore will be mined using surface miners. Surface miners can cutto an accuracy of 0.1 m and can extract ore without the need for drilling, blasting, or primary crushers to crush ore. Ore is loaded from the surface miner into trucks for transfer to the OPF. At Cloudbreak the Bigge development entered production in Q3 FY22. Bigge expands Cloudbreak further west and contributes low strip ratio material which supports the overall Fortescue product strategy.

Crushing/sizing Facilities The crushing and sizing facilities consist of a series of crushers designed to handle standard sized ore and large ROM oversize rocks generated in drill and blast operations, pit floor windrow cleanup and pit wall batter scraping at the mine. The crushing and sizing process will size material to less than 250 – 300 mm such that it can be transported by conveyor to the OPF. In 2021 the two C160 Metso jaw crushers in this building were installed second-hand during the construction of the Cloudbreak mine and were nearing their end of life. This project involved removing the old crushers and replacing them with two new C160 jaw crushers.

- subscription is required.