Integra Resources, which is focused on the exploration and de-risking of the past producing DeLamar gold/silver project, in Idaho, in the US, has increased the scope of the prefeasibility study (PFS) at the project, aiming at a 32 000 t/d to 35 000 t/d heap leach facility and an 8 000 t/d to 10 000 t/d mill facility.
The augmented scope and increased throughput at DeLamar is, subject to ongoing studies, expected to result in a 50% or greater increase in gold and silver production profile over a longer timeframe relative to the 2019 preliminary economic assessment (PEA), which estimated production of 124 000 gold-equivalent ounces a year over a ten-year period.
The PEA was based on a 27 000 t/d heap leach facility and a 2 000 t/d mill facility.
Integra reports that the larger milling scenario will accommodate additional unoxidised material that was excluded from the 2019 PEA and allow the company to produce additional silver ounces.
In the PEA, silver accounted for about 18% of the overall economics of the project; however, with a larger mill proposed in the PFS, the company now anticipates a much greater percentage of project economics to be driven by higher silver recoveries and production.
“In undertaking a PFS at DeLamar, Integra looked to increase the project’s production profile relative to the already robust 2019 PEA. The company specifically set its sights on larger production profiles and greatly enhanced potential revenue streams from silver production, given the large untapped silver resource base that exists on the project, in addition to a large gold resource base.
"We view DeLamar as ‘many-projects-in-one’ due to the optionality in both mining and processing options at the project. The optionality and expansion capability of our project, a key factor in our decision to acquire DeLamar nearly four years ago, will become clear in the upcoming PFS study that we expect to deliver in the fourth quarter of this year," Integra president and CEO George Salamis comments.
Integra points out that the estimated capital expenditure (capex) for the project is likely to increase, but says the increase will be in line with the larger production profile to be presented in the PFS.
"The increase in capex will be primarily driven by a larger production scenario to increase the annual production profile, as well as increased costs of raw materials.
"Integra’s commitment to responsible mining will also be prevalent in the PFS, including solutions to decrease carbon emissions through alternative transportation options for mineralised material and the use of renewable power," the company notes.