Base metals explorer Cyprium Metals (ASX: CYM) has released an updated mineral resource estimate for the Nifty copper deposit in Western Australia following the results of a drilling program and project restart study.
The new figures sit at 95.1 million tonnes grading 1% copper for a total contained copper inventory of 940,200 tonnes, reflecting a 28.4% (or 208,000t) increase on the previous estimate.
Total oxide resources have increased to 16.1Mt at 0.9% copper for approximately 144,300t, providing further near surface copper inventory for phase one of the project.
Cyprium confirmed the update used the same methodology, resource depletion, grade interpolation, density algorithms, quality protocols and classification codes as those reported in the maiden estimate released in November.
The new mineral resource estimate follows resource drilling at the Nifty West target which comprised 71 reverse circulation holes for a total 18,867m.
The program targeted lightly-drilled areas up-plunge of the former underground mine, in the keel area of the Nifty Syncline below the western end of the Nifty open pit.
It confirmed the continuation of significant copper mineralisation in the keel zone to the west at up to 100m thick, which is believed to be ideal for a large-scale open pit development.
Highlights were 20m at 0.70% copper from 210m, including 1m at 1.04% from 210m; 4m at 1.29% copper from 214m; 1m at 1.23% copper from 221m; and 1m at 1.42% copper from 225m.
Other results were 31m at 1.61% copper from 234m, including 14m at 2.72% from 235m; 13m at 0.55% copper from 268m, including 1m at 1.14% from 271m and 1m at 1.26% from 273m.
The Nifty deposit has been drilled and sampled using several techniques, with holes drilled from surface and underground and on variable spacings along and across the strike of the deposit.
Approximately 303,000m have been drilled in total within the immediate vicinity of the deposit.
Released in March, the Nifty project restart study focuses on a phase one development centred on heap leaching and solvent extraction electrowinning (SX-EW) to produce copper metal cathode on site.
Cyprium said the significant inventory and increase of heap leachable oxide mineralisation confirmed by the updated resource estimate presented additional upside opportunity on project economics.
Restart of the heap leach SX-EW facility will see a recommencement of open pit mining; refurbishment of existing heap leach agglomeration, stacking and materials equipment, and irrigation systems; refurbishment of leach pads and construction of additional leach pad capacity for retreatment of existing material; refurbishment of existing SX-EW facilities; and a re-instatement of supporting reagent systems.
The Nifty project already has substantial infrastructure in place including a 2.8 million tonnes per annum sulphide concentrator (placed on care and maintenance in late-2019); a 25,000t per annum copper cathode heap leach SX-EW facility (on care and maintenance since January 2009); a 21 megawatt gas turbine power station, gas pipeline and power distribution system; water supply and reticulation systems including multiple bore fields; heavy vehicle workshops and mining accommodation village; a sealed all weather airstrip; and a 4G communications network.