Cobre Ltd (ASX:CBE) has wrapped up the first phase of hydrogeological testing at the Ngami Copper Project (NCP) in Botswana's Kalahari Copper Belt and is now firmly on the path towards the development of an in-situ copper recovery (ISCR) process.
Low-cost, environmentally friendly method
This phase aimed to evaluate the feasibility of extracting copper-silver through a low-cost and environmentally friendly method, potentially transforming the prospects for the company and the wider region.
During the program, the company verified the presence of an enhanced permeability zone within a representative portion of the copper mineralised compartment. This zone is bounded by low permeability footwall and hanging wall competent 'seal' rocks.
A standout finding was from production well PW001 which was drilled down the main mineralised fracture zone and intersected a significant extension of copper mineralisation – 78 metres at 0.59% copper from 187 to 265 metres – confirming its depth continuity.
The company is now kicking off a second phase of long-term pumping and injection tests designed to evaluate aquifer characteristics over a greater distance for a longer period.
Geological studies have identified the mineralisation at NCP as sedimentary-hosted, structurally controlled copper-silver, favourable for acid leaching and amenable to ISCR.
The initial tests focused on a section of the copper mineralisation, estimated to hold between 103 and 166 million tonnes at grades of 0.38 to 0.46% copper.
Desktop work confirmed by fieldwork
Results have confirmed the presence of an enhanced permeability zone conducive to ISCR, surrounded by low permeability rocks which serve as natural barriers.
“Having our desktop work successfully validated with in-field tests marks a pivotal advancement in our journey to developing the ISCR project potential,” CEO Adam Wooldridge said.
“Given the scale of the target proving up a low-cost, environmentally friendly extraction method for copper-silver beneficiation will be a game changer for the company, local communities and greater Kalahari Copper Belt.”
The project's next phase involves long-term pumping and injection tests to assess aquifer characteristics over a broader area. This work has commenced, with results anticipated in the coming months.
Cobre thinks the production well's success in intersecting an extensive zone of copper mineralisation supports the viability of the ISCR model.
The ongoing hydrogeological program, overseen by WSP Australia Ltd, aims to provide a comprehensive understanding of the aquifer's properties, crucial for the advancement of the ISCR process.
Main image: Hydrogeological drilling, NCP Botswana.