ASX-listed copper developer Cobre has defined a fully funded, staged and modular expansion pathway for its 62%-owned Sierra Atacama project, in Chile, leveraging existing infrastructure and targeting an initial increase in copper cathode capacity to 18 000 t/y before increasing production to 25 000 t/y and further to 50 000 t/y in the long term.

Stage 1 of the project will comprise restoring the site's existing capacity to 18 000 t/y, with a detailed engineering review of the existing plant having established the scope to refurbish and upgrade the operating solvent extraction circuit and recommission the currently unused second electrowinning bay.

Cobre has launched a tendering process for the refurbishment and recommissioning works as part of the Stage 1 works, with awards to be confirmed by the end of the quarter.

Conceptual engineering is underway for refurbishment and recommissioning of the currently unused second solvent extraction line and development of an additional electrowinning bay, with regard to the 25 000 t/y expansion.

Cobre is also advancing engineering and environmental studies for submission as a Declaración de Impacto Ambiental to support the proposed expanded operation, which will include grid power connection, increased water supply, expanded leach and run-of-mine pads, increased crushing capacity and additional openpit mining areas.

The company will only evaluate a larger-scale development case targeting up to 50 000 t/y of copper cathode production once a 40 000 m drill programme, updated mineral resource modelling and expanded openpit mine design has been completed.

"Sierra Atacama provides Cobre with a compelling opportunity to accelerate copper production capacity in a capital efficient manner by leveraging the significant existing processing and mining infrastructure. This staged and modular approach allows us to pursue near-term production growth with relatively modest infrastructure capital requirements, while progressively engineering, permitting and de-risking the much larger Sierra Atacama development opportunity," says Cobre CEO Adam Wooldridge.