Name of the Project
Cadia expansion project.

Location
New South Wales, Australia.

Project Owner/s
Newcrest Mining.

Project Description
The Newcrest board has approved the first of two stages of the Cadia expansion project.

The first stage comprises the start of the next cave development (PC2-3) and an increase in the nameplate capacity of the process plant to 33-million tonnes a year.

The feasibility study for PC2-3 recommends several mine design changes from the 2018 prefeasibility study, including:

∙ the relocation of the crushing and materials infrastructure to the eastern side of the footprint, which has lower exposure to potential seismic activity, thereby enhancing the safety of personnel and reliability of the operation.

∙ an increase in the number of extraction drives (from nine to 14).

∙ a reduction in operational constraints, which is expected to increase production rates from 13-million tonnes a year to 15-million tonnes a year.

The plant expansion includes upgrades to concentrator circuits 1 and 2, the addition of a coarse-ore flotation circuit and ancillary upgrades to equipment.

Concentrator 1 is currently constrained by secondary crushing motor power and semiautogemous grinding (SAG) motor power. The plant expansion works in Stage 1 of the Cadia expansion project aim to increase Concentrator 1 throughput in stages, from 23-million tonnes a year up to 25-million tonnes a year through conveyor upgrades, and the installation of a new secondary crushing circuit, which together, are expected to increase throughput by one-million tonnes a year. The works also aim to replace a SAG mill motor to increase power from 20 MW to 22 MW, also with an expected increase in throughput of one-million tonnes a year.

The Cadia expansion feasibility study recommends increasing the grind size, which allows for a further one-million tonnes a year in expected throughput of Concentrator 1 to a total rate of 26-million tonnes a year. Together with the currently installed capacity of Concentrator 2 of seven-million tonnes a year, this provides Cadia with 33-million tonnes a year of milling capacity.

The second stage is focused on a further increase in processing capacity to 35-million tonnes a year and recovery-rate improvement projects targeted for completion in 2022, ahead of the completion of the cave development.

Average yearly gold production is estimated at 381 000 oz and average yearly copper production at 77 000 t over the project’s 45-year mine life.

Potential Job Creation
Stage 1 and 2 of the Cadia expansion project are expected to generate direct employment of about 860 people at peak.

Net Present Value/Internal Rate of Return
The net present value for both stages is estimated at $1.17-billion, with an internal rate of return of 21.5% and a payback of 7.6 years.

Capital Expenditure
Stage 1 is estimated at $685-million and Stage 2 at $180-million.

Planned Start/End Date
The PC2-3 mine is targeting first production in the 2023 financial year.

Latest Developments
Newcrest received approval from the New South Wales Department of Planning, Industry & Environment (DPIE) in December 2021 for a modification to increase the permitted processing capacity of Cadia from 32-million tonnes a year to 35-million tonnes a year.

The Newcrest board previously approved progression to execution of a two-stage expansion of Cadia, including an increase in plant capacity to 35-million tonnes a year. Execution of the works for both stages of the expansion is in progress, with completion expected in the September quarter of 2022.

The modification also provides approval for Newcrest to repair the slumped section of the Northern tailings storage facility (NTSF) at Cadia and revise the footprint of the NTSF and southern tailings storage facility to allow for a change from an upstream to a centreline lift design.

The modification is subject to conditions, including Newcrest commissioning an independent audit report to the satisfaction of the DPIE Secretary in relation to Newcrest’s approach to managing and minimising the off-site air quality impacts of the project.

The Newcrest board approved gating of the NTSF embankment remediation to feasibility study in July 2021. Detailed design work on a single design option is in progress, with execution expected to cost less than A$100-million.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Newcrest Mining, tel +61 3 9522 5333 or email corporateaffairs@newcrest.com.au.