The entire haul truck fleet at the Chichester Hub iron ore operations was converted to Autohaul by October 2020. Image courtesy of Fortescue Metals Group Ltd.
The Chichester Hub comprises the Cloudbreak and the Christmas Creek iron ore mines in the Pilbara region of Western Australia. Image courtesy of Fortescue Metals Group Ltd.
The iron ore production capacity of the Chichester Hub is 100 million tonnes per annum (Mtpa). Image courtesy of Fortescue Metals Group Ltd.

The Chichester Hub iron ore operations, located in the Pilbara region of Western Australia, comprise two large-scale, open-pit mines, namely Cloudbreak and Christmas Creek.

Fully owned and operated by Fortescue Metals Group (FMG), the integrated iron ore mining and processing hub has an annual production capacity of approximately 100 million tonnes (Mt).

The Chichester Hub has been the demonstration site of FMG for the application of modern leading technologies to achieve greater efficiency and minimise the carbon footprint.

The Christmas Creek ore processing infrastructure was upgraded with the installation of a wet high intensity magnetic separator (WHIMS) plant to maximise production in 2020, while the Cloudbreak mine utilises the innovative relocatable conveyors that have been extended to cover 10km, from the initial length of 5km.

The entire haul trucks fleet of the mining hub was also converted to an autonomous haulage system (AHS) in 2020, while a renewable hydrogen mobility project, as well as a solar-gas hybrid project to displace diesel consumption in the existing Christmas Creek and Cloudbreak power stations, are currently underway.

Geology and mineralisation

The Cloudbreak and Christmas Creek iron ore deposits are located within the Chichester Ranges, in northern Western Australia. The Christmas Creek mine lies approximately 40km east of the Cloudbreak deposit.

The iron mineralisation at these deposits is primarily hosted by the Nammuldi Member, the lowest member of the late Marra Mamba Iron Formation (MMIF) of the Archaean Age.

Estimated to be up to 60m-thick, the Nammuldi Member comprises extensive, thick, and podded iron-rich bands, separated by siliceous and carbonate-rich chert and shale units.  It is overlain by black shales and volcanic rocks of the Jeerinah Formation.

The iron mineralisation is characterised by hematite, goethite, and ocherous goethite, with the majority of the iron mineralisation occurring as martite-goethite.

Iron ore reserves at Chichester Hub

The Chichester Hub was estimated to hold approximately 1.4 billion tonnes of proved and probable ore reserves grading 57.1% Fe as of June 2020. The Christmas Creek accounted for 843Mt, while the ore reserves at Cloudbreak were estimated to be 560Mt.

The total measured, indicated, and inferred resources at the mining hub were estimated to be 2.78 billion tonnes grading 56.2% Fe.

Mining and ore processing

The open-pit mining method involving conventional load and haul operations is employed at the Cloudbreak and the Christmas Creek mines.

The mining fleets at the Chichester Hub comprise Cat 793F, 789D, and Komatsu 930E haul trucks, apart from a number of excavators, wheel loaders, and light vehicles.

The extracted ore is processed at one of the three ore processing facilities (OPFs) in the hub for the production of both lump and fine products.

The construction of a wet high-intensity magnetic separation (WHIMS) plant to enhance the recovery of fine-grain ore feed at the Christmas Creek OPF was completed by the end of 2020.

The final products from the Chichester Hub are transported via the 620km-long heavy haul railway network connecting the five-berth Herb Elliott Port and the Judith Street Harbour towage facility in the Port Hedland.

Fleet automation at Chichester Hub

Fortescue completed the conversion of the entire fleet of 108 haul trucks at the Chichester Hub to autonomous haulage (AHS) in October 2020.

The other mining equipment including, excavators, wheel loaders, and light vehicles are also integrated with the autonomous fleet using CAT Minestar Command for Hauling Technology which is operated from the Fortescue Hive, FMG’s integrated operations centre in Perth, Western Australia.

The company also announced the successful operational deployment of autonomous light vehicles (ALV) at the Chichester Hub in February 2021. Four Ford Rangers were retrofitted with an on-board vehicle automation system with the assistance of Ford Australia, in order to improve the efficiency of the Christmas Creek mobile maintenance team.

Renewable hydrogen mobility project

In August 2020, FMG announced an £18m (A$32) renewable hydrogen mobility project involving the deployment of ten full-sized hydrogen coaches, to be custom built by HYZON Motors.

It will be supported by the installation of a hydrogen refuelling station, which will use the renewable electricity from the Chichester solar-gas hybrid project for the generation of renewable hydrogen onsite.

Fortescue entered into a partnership with ATCO Australia (ATCO) to build and operate an integrated hydrogen production and refuelling facility in April 2020.

Chichester solar-gas hybrid project

The Chichester solar-gas hybrid project, also known as the Alinta Fortescue solar-gas hybrid project, involves a 60MW photovoltaic (PV) solar generation facility integrated with a 35MW battery storage facility at Alinta’s Newman gas-fired power station in the Pilbara region, and a 60km transmission line connecting the Chichester operations with the Newman gas-fired power station.

The project is being developed by Alinta Energy with an estimated investment of approximately £80m ($100m). Alinta Energy will also own and operate the facility.

The pre-commissioning activities for the project were started by the end of 2020. Scheduled for commissioning in 2021, the solar-gas hybrid project is expected to avoid approximately 100 million litres of annual diesel consumption by the existing Christmas Creek and Cloudbreak power stations.

Contractors involved

SIMPEC, a subsidiary of WestStar, was awarded a £1.5m ($2.1m) contract for replacing two C160 jaw crushers at the Cloudbreak mine in March 2021.

Central Systems, a wholly-owned subsidiary of Resource Development Group (RDG) was awarded a contract for the design and construction of an overpass at the Cloudbreak mine site in June 2020.

RCR Mining Technologies (RCRMT), a wholly-owned subsidiary of NRW Holdings was contracted to design and construct a new relocatable crushing plant at the Cloudbreak mine in October 2019.

NRW Holdings was also contracted for the earthworks for the railroad and the ore processing facilities for the Cloudbreak and the Christmas Creek previously.

Primero Group was awarded the engineering, procurement, and construction (EPC) contract for the wet high-intensity magnetic separation (WHIMS) project at the Christmas Creek iron ore mine in February 2020.

Melchor Contracting was subcontracted for the concrete package, while WestStar Industrial won a contract for process piping fabrication works for the WHIMS project in August 2020.

Thiess was contracted to install the autonomous haulage technology at the Chichester Hub mining operations in November 2018.

Downer, an Australian integrated services company, was awarded contracts worth approximately £90m (A$165m) by Alinta Energy to build the 60MW Chichester solar farm, as well as support power infrastructure in the Pilbara region as part of the Chichester solar-gas hybrid project in October 2019.