Newcrest Mining Cadia East Gold/Copper Mine - EPC

Client: Newcrest Mining

Location: New South Wales, Australia

Map showing the location of Newcrest Mining Cadia East Gold/Copper Mine - EPC

Executive Summary

Cadia East was Australia's first panel-cave mine and is its largest underground mine. Fluor was the procurement and construction manager for the surface process plant and underground material handling, as well as engineering, procurement and construction management for surface and underground infrastructure. We also had commissioning responsibility for all new facilities and services. Fluor acted as the owner's representative for all project engineering, procurement and construction deliverables.

Client's Challenge

The Cadia East project is located near Orange, New South Wales, Australia. Orange is a rural community with a large number of wineries, orchards and sheep and cattle farms. Developing a large gold mine expansion project in the middle of a quiet rural community without impacting the quality of life added to the project's challenges.

The Cadia East deposit is a porphyry zone (rock of feldspar crystals embedded in a compact dark red or purple groundmass) with gold-copper mineralization. Adjacent to the edge of the existing Cadia Hill open pit, the deposit extends up to 2.5 kilometers east. The system is up to 600 meters wide and 1.9 kilometers deep. The adjacent open pit was in its 11th year of production and bulk mining was completed in 2012.

The Cadia East orebody is one of the world's largest gold deposits, with a mineral resource of 2,347Mt containing 33.2 Moz of gold and 6.59 Mt of copper, along with a current ore reserve of 18.7 Moz of gold and 3.16Mt of copper. It was expected to underpin production from the Cadia Valley for at least the next 30 years.

Newcrest Mining Limited (NML) determined that panel caving was the best means to develop the orebody and to deliver the expected economic benefits.

Source: Newcrest website.

Fluor's Solution

We managed the feasibility study, while Newcrest completed development of a seven-kilometer underground decline to access the orebody, six kilometers of other development, additional diamond drilling of more than 45 kilometers and data collection and studies covering geotechnical and metallurgical areas. In order to determine the optimal mining and processing methods, we worked closely with engineering designers and NML.

We were awarded the implementation immediately after the feasibility. Our role included managing specialist engineers for the design of the underground materials handling systems and the processing plant. Detailed design, procurement, construction management and no-load commissioning were also provided for the surface and underground infrastructure, including:

Earthworks for roads, parking areas and water pipeline routes.
Site buildings including mine change houses, offices and the site entry complex.
Pump stations and water pipelines to the water storage facility.
Upgrades of existing operating facilities, including water storage.
Upgrades to the 132 kV switchyard in the plant area.
New 132 kV duplicate feeder in the urban area of Orange City, which would service the HV power line to the Cadia site.
Underground mine dewatering.
Underground high voltage (HV) power and communications backbone.
Underground mine raw water supply.
New concentrate pipeline to an offsite filter plant some 30 kilometers from the mine site.

For the process plant upgrade and underground mine, our scope included management of specialist engineers, procurement, construction management and precommissioning of the facilities, which included:

Underground crushers and materials handling equipment transporting crushed material to the surface coarse ore stockpile.
Upgrade of the existing low grade concentrator including new ball mill circuit, screening building and upgraded crushing circuit, new high pressure grinding rolls and flotation circuit.

Installation of the underground facilities involved extensive daily coordination with mining operations for access of personnel and material as well as coordination with daily blasting schedules.

Similarly, the expansion of the low-grade concentrator required construction and commissioning activities to be performed in and around existing operating plant with minimal lay down areas and extensive interfaces with plant operations. These interfaces demanded a high level of coordination and execution planning to enable the construction and commissioning activities to progress without impact to operations. Pre-assembly of equipment to a maximum extent possible was also essential to minimize congestion and impacts to the operating plant.

Our on site construction organization consisted of over 100 Fluor contracted personnel, 150 contractor indirects staff, and 800-plus workers, with the majority on a fly in/fly out assignment basis.

Conclusion

The $AU1.9 billion development of the Cadia East deposit was an endorsement of the Newcrest strategy of controlling large mineral districts in order to secure long-life mining operations and to efficiently use existing infrastructure and capital.

Our scope of work was completed and commissioned in 2012.

Looking ahead, Cadia East has the potential to be further expanded.