Eagle Mountain Mining Limited (ASX: EM2), a copper-gold explorer, is thrilled to announce substantial advancements in its 100% owned Oracle Ridge Copper Mine Project in Arizona, USA. The company's recent developments in metallurgy and communication have paved the way for a groundbreaking simplified process to produce copper on-site through leaching, solvent extraction, and electrowinning.
As part of its strategic vision, Eagle Mountain is committed to establishing itself as a mid-tier copper producer in the United States. The Oracle Ridge Copper Project is at the forefront of this vision, showcasing a potential for a simplified process flow sheet. This innovative approach is expected to yield LME grade copper directly at the site, significantly reducing both capital and operating costs. Moreover, this method is anticipated to have a substantially lower environmental impact compared to traditional mining and processing techniques.
Key highlights from the recent testwork at the Oracle Ridge Project include:
- Mining: The updated Mineral Resource indicates the feasibility of larger stopes and multiple mining fronts, which are expected to enhance productivity and reduce unit operating costs. The site's elevated position is also ideal for employing a battery haulage fleet.
- Ore Sorting: Preliminary results suggest up to a 30% increase in copper head grade by removing lower grade ore or waste, potentially lowering capital and operating costs due to reduced grinding requirements.
- Crushing: Initial tests indicate that high pressure grinding rolls are well-suited to Oracle Ridge rock, offering advantages such as lower power requirements and a reduced operating footprint compared to traditional crushing methods.
- Flotation: Exceptional average rougher flotation recoveries of 93% Cu at a 100µm grind size have been achieved, with a mass rejection of 92%. Future work aims to further enhance these recoveries, reducing capital and operating costs, as well as the environmental footprint.
- Sulphide Leaching: Preliminary glycine leaching tests on run-of-mine mineralization have shown copper recoveries up to 91% at P80 100µm grind size. This promising result is leading to expanded testwork, including concentrate leaching and heap leaching of lower grades.
The Locked Cycle testwork, indicative of standard flotation circuits, has produced a copper concentrate grade of 25% Cu with an average of 90% copper recoveries.
Eagle Mountain Mining Limited is excited about these developments and remains dedicated to implementing innovative and environmentally responsible mining practices. The Oracle Ridge Copper Mine Project is not just a venture in mining but a step towards sustainable and cost-effective copper production.
Commenting on the results, Eagle Mountain Mining’s CEO, Tim Mason, said:
”I’m very excited that our team has identified a far simpler processing method for mineralisation at Oracle Ridge with a raft of cost and environmental benefits. Excellent copper recovery from rougher flotation alone paves the way for direct tank-leaching of the concentrate which in turn feeds to an SX/EW plant onsite that produces LME grade copper sheet. There is no need for filtering and shipping of concentrate to smelters and refiners.
Additional feedstock to the SX/EW could come from a low-grade heap leach process which is in the testing phase. If viable, this could negate the need for a tailings storage facility, eliminating those capital and operating costs for the project.
Glycine leaching is currently being tested on run of mine ore and low grade material. Results received to date are very encouraging and the next stage will be testing the rougher concentrate and the existing tailings.
Importantly, the recent inclusion of copper on the US critical materials list means that production of LME grade copper onsite at Oracle Ridge positions the Company to pursue various US Government funding opportunities.
I am very excited by these latest developments which support our goal to become a mid-tier copper producer in the USA.“
Eagle Mountain is a copper-gold explorer focused on the strategic exploration and development of the Oracle Ridge Copper Mine and the highly prospective greenfields Silver Mountain Project, both located in Arizona, USA.