With the first stope backfilled and its paste plant commissioned, Nevada Copper’s Pumpkin Hollow underground mine is in perfect step and has achieved the first ore feed to the complex’s mill.
The producer said October 3 that processing operations have now recommenced at an initial feed rate to the mills of 3,000 tons per day (t/d), which now permits its process team to optimize reagent addition and establish and reinforce operating procedures to ensure consistent operations. The mill, which is being recommissioned on lower-grade ore stockpiles, will soon transition to a combination of mined stope ore and stockpiled ore.
Throughput will now increase steadily by mid-month towards a steady-state goal of 4,500-5,000 t/d, which it said it should reach by the end of 2023. Once that steady-state operation rate is met, it is examining the potential via optimization opportunities in 2024 to increase mill throughput potential beyond 5,000 t/d.
Additionally, Nevada Copper said, with its third dike crossing completed last month, it has now cleared the way for its progress into planned 2024 stope development.
“Continued development beyond the dike is to ultimately provide a full ventilation circuit for the Lower East North stoping areas, but it also provides additional headings for the development contractor to open targeted 2024 stopes,” officials said, noting that rock conditions beyond the dike will continue to be as predicted by its geotechnical model.
Pumpkin Hollow’s initial stope in its 2023 mining sequence was mined in July and August, with 9,000 tons of ore extracted in the Sugarcube area of the East South (ES) Zone. Backfilling activities began in September and a full stope was backfilled, completing successful testing of both the surface paste plant and the underground paste delivery system.
“This Sugarcube stope is part of the ES Zone planned stopes and ground conditions encountered during mining were conducive to a successful paste backfill,” the company said. Currently, the next step forward will be drill and blast on the next planned stope, which is in the Alphabet area of the ES Zone. It is in progress and expected to meet 20,000 tons of ore by the end of the month.
The mine is also seeing the balance of its capital projects moving ahead, including works on the underground crusher and ore handling system. The Geho dewatering system is mechanically complete, it added, and with electrical and piping installations also in process, it is expected to be completed and commissioned by the end of October.
Finally, one reverse circulation drill should be on site the week of October 3; it has a primary goal of a 5,000-foot drill program to follow-up on recent results and historic sampling. The Copper Ridge and Dimples target areas are outside of the current mineral resources and have the potential to establish additional mineral resources within the Pumpkin Hollow property, it said.
President and CEO Randy Buffington called the restart of processing operations a “critical milestone” and said Nevada Copper is proud of its progress.
“The restart of the mill has been orchestrated through careful planning and establishing the infrastructure needed to ensure sustained process plant operations, including the building of significant surface stockpiles and progression on critical capital projects. We are now well positioned to move towards steady state operations of 5,000 tons per day. My sincerest thanks to the entire Nevada Copper team and our business partners for their tireless efforts in achieving this important milestone for the future of Pumpkin Hollow,” he said.
Nevada Copper will produce copper, gold and silver via open pit and underground workings at Pumpkin Hollow.
Source: Nevada Copper