"The Gunnison copper project is distinctive in the world of copper mining due to its in-situ recovery method."

Stephen Twyerould

CEO AND PRESIDENT, EXCELSIOR MINING

January 19, 2024

What are the most recent updates regarding the Johnson Camp Mine (JCM) project?

The JCM open pit saw its last mining activity in 2010, when the high-grade oxide was depleted and the high-grade sulfide was encountered. Back then, the technology for sulfide leaching was not advanced enough to continue operations. However, recently we partnered with Nuton, a Rio Tinto venture, to explore a combined approach of oxide and sulfide leaching at JCM using Nuton’s suite of bio-leach technologies.

Nuton's sulfide leaching technologies have significantly advanced, enabling us to access the previously unmined 1% sulfide copper at the bottom of the pit. Our plan involves extracting the high-grade sulfide alongside the surrounding oxide to revive the open pit. We are well-positioned for this endeavor as we already possess the necessary infrastructure, including a fully permitted solvent extraction-electrowinning (SX/EW) plant and ponds. If all the test work proves favorable for our commercial mine design, we aim to break ground at JCM sometime in H1 of 2024.  This would be a great outcome for our company and Nuton. 

Can you explain the conditions of the partnership with Nuton?

The initial phase of our program involves mining sufficient sulfide material from the pit's bottom to create a large-scale commercial demonstration of the Nuton technologies. Nuton funded this initial phase, including the drilling and other activities, totaling approximately US$3 million, with Excelsior remaining the operator. It is important to note that Nuton has neither purchased shares of Excelsior, nor is it providing a loan. Instead, they have made direct payments for the work being carried out. 

As we bring the mine into production and generate cash flow, that income will be used to repay Nuton's initial construction costs for the commercial demonstration. The intellectual property rights to the Nuton technologies remain with Nuton. At the end of the three to five-year trial, Nuton can exercise an option to establish a joint venture for the remaining 15 years of the mine's life.

What are the environmental benefits of the Nuton technologies?

By moving directly to leaching, we avoid the energy-intensive processes of grinding and concentrate production, along with the associated tailings disposal and water consumption required for concentrate creation. Furthermore, eliminating tailings means we avoid managing large piles of potentially environmentally hazardous material. Additionally, because we generate copper on-site through a SX/EW plant, there is no need for downstream processing like roasting or smelting, which consumes energy and can produce emissions.

What are the advantages of ISR that you plan to adopt in the Gunnison Copper Project?

The Gunnison Copper Project is distinctive in the world of copper mining due to its in-situ recovery method (ISR). This approach involves drilling a network of closely spaced injection and recovery wells to circulate a mining solution underground, dissolving the copper. The process eliminates traditional mining activities, resulting in no excavation, tailings and minimal waste. It significantly reduces water consumption and greenhouse gas emissions, making it an environmentally unparalleled approach in the mining industry.

While in-situ mining is well-established for uranium, lithium, and other commodities, it is relatively rare in copper mining. We successfully amended our EPA operating permit in 2023 to allow for well stimulation and are planning to conduct field trials in H1 2024. If the trials prove successful, we plan to optimize and integrate this approach into our commercial production plan, ultimately getting back into production and regaining the value of our Gunnison Copper Project.

What are the challenges associated with copper projects in the US?

The US has ample domestic reserves, especially in states like Arizona. Numerous large-scale copper projects within the country can meet a significant portion of the domestic copper demand. Therefore, the challenge for copper, from a critical minerals’ perspective in the US, is not so much about developing new projects or technologies to secure the supply chain. Instead, it is about government agencies supporting and facilitating the development of existing projects within the country.

In our case, the in-situ copper recovery method aligns well with the green objectives of the current administration and the Department of Energy, making our project unique. However, for standard copper projects, the focus should be on promoting and streamlining the development of the abundant copper resources available in the US. 

INTERVIEWS MORE INTERVIEWS

"We will continue supporting sustainable raw materials production and the development of new alternatives."
"In the past, we diversified into the fuel market with a company called Exxia. Today, we have the new specialties company, Ion."
"Asian Battery Minerals is Australia-based company with three critical minerals projects in Mongolia."
"We have seen a remarkable increase in revenue, surpassing 120% YoY."

RECENT PUBLICATIONS

Western USA Mining 2024

GBR's Western USA Mining 2024 report offers a comprehensive overview of the current state of the mining industry and what Washington and all stakeholders across the mining value chain are doing to achieve mineral independence.

MORE PREVIOUSLY PUBLISHED

MACIG

"We believe technology should enhance, not replace, the role of geologists in exploration."

SUBSCRIBE TO OUR NEWSLETTER