Copper Mine Expansion Moves to Full Execution
Engineering and equipment firms serving mining construction now have a committed brownfield scope to plan procurement and staffing around.
Updated on Nov. 5, 2026 in Construction
Fluor Corporation has received full notice to proceed under its engineering, procurement and construction management contract for the Fourth Grinding Line Expansion at Sierra Gorda, a copper-molybdenum mine in Chile's Antofagasta Region. The brownfield project will add a fourth process line for operators in the global mining construction sector.
Why it matters
The expansion lifts concentrator capacity from approximately 130,000 to 165,000 tonnes per day, a move that reflects joint venture partners' decision to add processing throughput at an existing site rather than build new capacity from scratch. For contractors and suppliers in mining construction, a full notice to proceed converts a previously approved project into committed scope and schedule.
The project lifts concentrator throughput from roughly 130,000 to 165,000 tonnes per day, about a 27% increase, and is expected to add approximately 30% to copper equivalent output. Post-completion annual payable production is projected at about 195,000 tonnes of copper, 6,000 tonnes of molybdenum, 58,000 ounces of gold and 1.7 million ounces of silver.
The players
Fluor Corporation
A large US-based engineering and construction firm whose EPCM role places it in charge of project design coordination, procurement and construction management on the expansion.
Sierra Gorda SCM
The operating company behind the Sierra Gorda copper-molybdenum mine, which owns the concentrator being expanded.
KGHM Polska Miedź S.A.
A Polish copper producer and joint venture partner in Sierra Gorda that approved execution of the fourth grinding line project.
South32
A diversified mining and metals company headquartered in Perth, Australia, and a joint venture partner in Sierra Gorda that approved the expansion.
The details
The project is a brownfield expansion that adds a fourth process line to the existing concentrator, including a new primary crusher, a high-pressure grinding roll crusher, fine ore grinding, flotation and support facilities. Fluor is serving as engineering, procurement and construction management contractor, meaning it coordinates design, sourcing and construction oversight rather than only building components. Because the work is built onto an operating site, sequencing with existing plant operations is a central execution consideration.
Timeline
Earlier in 2026: Sierra Gorda joint venture partners approved execution of the fourth grinding line project.
November 5, 2026: Fluor received full notice to proceed under its EPCM contract.
2027: Construction activities are expected to start.
Market Landscape
Brownfield expansions of existing concentrators are a common route for copper producers in Chile to add output without the lead times of greenfield development. This Sierra Gorda project follows that pattern, adding a fourth grinding line to a mine that already operates at scale.
Engineering, procurement and construction firms should note that brownfield concentrator expansions in Chile are moving to full execution with a single EPCM contractor coordinating scope. Equipment suppliers and specialist subcontractors for crushing, grinding and flotation should watch for procurement packages as the 2027 construction start approaches.
The takeaway
Operators in mining construction should treat a full notice to proceed as the point where scope, schedule and procurement become committed, and should track when subcontract and equipment packages are issued ahead of the 2027 start. Watching how the project's cost and schedule evolve through the expansion will show how brownfield EPCM work performs at this scale.
What happens next
Construction activities are expected to start in 2027, when the project moves from contract award into physical work at the site.
Further reading
For more on how projects like this are built and staffed, see the Construction section.
