Pumpkin Hollow Underground Mine Continues Towards Restart

Pumpkin Hollow Underground Mine Continues Towards Restart

YERINGTON, NV – Randy Buffington, President and CEO of Nevada Copper, said “Since restarting mining and milling operations, Pumpkin Hollow underground mine, we’ve made progress in a number of areas, including completion of life of mine projects such as the Geho dewatering system and phase two of the underground crushing and ore handling system, development of significant stope inventory underground and realignment of the site operations team, under the leadership of Chuck Pollard as Assistant General Manager. However, several unforeseen setbacks impacted our progress on meeting operational targets. We took critical steps and refocused resources to mitigate and address these issues. The hoisting and ore handling system has returned to full capacity and mill operations continue to incrementally improve with over two months of mill feed stockpiled on surface. While I am disappointed that these challenges have negatively impacted our ability to meet hoisting and processing targets, we continue to ramp-up toward steady state operations.”

Several key milestones have been achieved across many aspects of the mine, including completion of critical LOM projects and restart of all significant operations, however, key fourth quarter operational targets were not met. The following challenges impacted our progress in the fourth quarter: 1) Underground dewatering – A build-up of water underground from increased development activities prior to completing the Geho dewatering pump project, caused several delays in progress including hoisting, capital projects construction, development and operations. The Geho pumps were successfully commissioned in November 2023, doubling pumping capacity, and all efforts were focused on removing the water from critical areas of the mine, which has now been cleared. Smaller pockets remaining are not expected to impact progress on stope mining or other development activities going forward. Full hoisting capabilities resumed in December 2023 and, with commissioning of the Geho system and additional surface infrastructure in place, we should now have sufficient pumping capacity to manage any temporary surges that are encountered. Additionally, we are implementing water reduction strategies including grouting programs to help reduce water inflows to mining areas. 2) Ore handling – Completion of the ore handling portion of the underground crusher and ore handling system and a third ore pass in late 2023 has provided additional ore handling capabilities. Material handling is being routed through three existing ore passes and the recently completed ore handling facility noted above. Automation improvements to the hoisting system were made in December to increase reliability and consistency in operations with the expectation that further increases in hoisting rates would be achieved. Hoisting rates in January have improved dramatically, having achieved a daily record of 4,475 tons. Stope mining is planned to resume in February 2024 and ore handling and hoisting capabilities are expected to meet underground material deliveries and process plant operations. 3) Process plant – The mill restarted in October 2023 and operated intermittently throughout the fourth quarter of 2023. The milling and flotation circuits operated well, achieving expected recoveries during periods of stable operations, however, unanticipated bottlenecks were encountered in the thickener and tails filter presses that caused repeated mill shutdowns. With the assistance of a technical consultant, upgrades to the filter presses, thickener equipment and operating protocols were made through December and into January. The second phase of the paste plant that delivers thickened tails directly to the paste plant has been fully constructed. Commissioning of the second phase is planned for February as stope mining resumes. Approximately 40-45% of the thickened tails will bypass the filter presses and go directly to paste plant in full operation, reducing the operational demand on the filter presses.

In addition to the completion and commissioning of the Geho dewatering system and the second phase of the ore handling system, other LOM infrastructure improvements include the drilling of a new fuel delivery hole, drilling of a second paste hole that will provide life-of-mine paste delivery for EN Zone stopes and improvements to the water infiltration system on surface to handle excess surge capacity. A scope of work is being issued to potential contractors for the final phase of the ore handling system, which includes installation and commissioning of the crushing system.

The Company completed its 2023 drill program with a total of 11 holes (3,305 feet) drilled on the Copper Ridge target and 9 holes (1,653 feet) on the Dimples target. Preliminary assays continue to be received and analyzed by the Company and indicate that mineralization and alteration found at surface has been intersected in the drill holes.