STUDIES for the Golpu component of the Wafi-Golpu Joint Venture between Harmony Gold and Newcrest Mining have confirmed a robust investment case that supports proceeding with the project. Study results are supported by high grades and early cash flow while costs will be in the lowest quartile for copper.
“The Golpu porphyry is a world-class resource due to its size, high grades, long-life and low operating costs,” said Harmony CEO Peter Steenkamp. “The mine design allows optionality and flexibility to scale the operation up with a relatively low capital investment.”
The Stage 1 feasibility study justifies development of twin exploration access declines, with two proposed block caves designed to extract approximately 50% of the contained gold and copper of the Golpu reserve. The remaining reserve is to be extracted in Stage 2 by a deeper block cave. Stage 1’s common path mining and processing infrastructure will be utilised in support of Stage 2 development.
The project will only progress into execution upon the grant of a Special Mining Lease (SML) which will include all necessary permits, approvals and consents required from the PNG Government, landowners and other relevant stakeholders. If a pre-mining development agreement is signed prior to an SML, approval will be sought from the boards of both parties to bring forward the advanced exploration work and earthworks for establishment of the access declines.
Advanced exploration via underground access will afford an opportunity to obtain further data at depth and as a result, a revisit of the proposed Stage 1 base case capital profile, schedule and execution approach.
The Stage 2 pre-feasibility study was conducted in parallel. The first step looked at debottlenecking Stage 1’s 6 million tonnes/annum capacity. This increased capacity to 7 million tonnes by making minor and low cost modifications to the process plant grinding circuit and underground material handling system.
The second step is increasing the production rate. By optimising existing infrastructure and increasing the size of the underground loader fleet a higher mining production output can be achieved, without significant capital investment. A second process plant with annual capacity of 7 million tonnes will be constructed to bring total plant capacity to 14 million tonnes.
The third and final stage investigated was construction of a third block cave. Additional capital is required to extend the decline access and conveyor belt system, the ventilation system and establish the associated underground infrastructure.