Fortescue Metals Group
Reserves (Cloud break and Christmas Creek)
Proven: 138Mt Probable: 490Mt
Up to 2024
Open pit strip mining
The Cloud Break iron ore mine is located in Pilbara, Western Australia. The mine is owned and operated by Fortescue Metals Group.
The mine, which began production in 2008, produces nearly 38Mtpa of iron ore. The total ore shipped from the site, however, amounts to 45Mtpa, including ore from Christmas Creek mine, which is also processed at Cloud Break.
Cloud Break is one of the three iron ore mines operated by Fortescue in the Pilbara region, with the other two being Christmas Creek mine and the Solomon project.
A $220m expansion to increase mine production to 50Mtpa is in the planning stage, with the final environmental scoping document approved by the EPA in March 2011.
Cloud Break mine iron ore reserves
The mine has total reserves of 628Mt at 60% Fe. The proven reserves are 138Mt and the probable 490Mt.
Cloud Break mine geology
The deposit lies within the Hamersley Basin, an area characterised by granitoid rocks of the Pilbara Craton, which is 2800 – 3500 million years old. The rocks are hosted under the Fortescue group.
The lowermost unit of the Hamersley group is formed by the Marra Mamba Formation (MMF).
The structural fault runs from northeast to southwest. The ore bodies are concealed beneath the deposits but are on surface at some sites.
Geologically the deposit is similar to Christmas Creek. The geological region has various other mines including Mount Nicholas, Mount Lewin and Mindy Mindy. There are more than 20 mines within the upper Fortescue River catchment.
Mining and ore processing
Cloud Break is mined through open pit strip mining. The pits are mined progressively, with the overburden of the opened pit used to backfill the older pits. Drill and blast methods are used to break open the overburden.
In order to ensure safe access to the ore, the groundwater levels are lowered beneath the pit floor by reinjecting extra water into several acquifers via multiple pipes and injection bores.
The ore is extracted using a combination of face shovels and excavators and surface miners. Larger and advanced 4200 surface miners were put into service at the mine in 2011. Excavators are used to access narrow bands of the orebody that cannot be accessed by surface miners.
The ore is transported via trucks and seven delivery conveyors to the ore processing facility (OPF). Here the ore is screened, crushed, blended and separated from sand and clay. The processed ore is loaded into carriages for transport to Herb Elliott Port at Port Hedland.
Ore transport at Cloud Break mine
Fortescue runs a 280-km rail line from the Cloud Break mine to the Herb Elliott Port. The line became operational in 2008.
The track withstands trains up to 2.8km long and weighing 30,000t. The 40t axle load railway is claimed to be the heaviest in the world.
The company has a rolling stock of 15 GE diesel locomotives and about 900 freight wagons. Four trains carry the ore from the mine to Herb Elliott Port in a five-hour journey.
Herb Elliott Port is spread over two million square metres. Both the rail and the port infrastructure are owned by The Pilbara Infrastructure, a wholly-owned subsidiary of Fortescue.
Expansion of the Cloud Break iron ore mine
Fortescue is planning to expand the footprint of the mine from 30 hectares to 45 hectares to increase its production to 50Mtpa over 14 years.
The ore processing facility will be upgraded to include an ore wash plant to wash saline ore in the later stages of mining.
Mining depth will be increased from 70m below ground level to 90m below ground level.
Christmas Creek iron ore mine is operated by the Fortescue Metals Group (FMG), Australia’s third-largest iron ore producer. The mine is part of FMG’s integrated mining operations, which include Cloudbreak, an established FMG mine.