This milestone follows a five-month programme to refurbish the third ball mill at the Nolans processing plant; recommissioning of the mill began in August of last year.
Prior to this, the plant had capacity to treat up to 3Mtpa of gold-bearing ore through a three-stage crushing circuit. The upgraded grinding circuit now utilises the additional 4,000kW ball mill to increase the overall primary and regrind milling capacity to 5Mtpa.
The first stage of the project targets production of about 80,000oz at an all-in sustaining cost of A$1,600/oz in 2020.
According to Resolute, doing this at a "reasonable cost" will ensure Ravenswood generates positive operating cashflows during the subsequent development phases of the expansion project.
With the increased processing capacity, Resolute can process greater volumes of the low-grade mineralised stockpiles that are available at Ravenswood. Available stockpiled material currently includes an inferred mineral resource of 32.6 million tonnes at 0.4 grams of gold per tonne for 390,000oz.
The miner said beneficiation of the stockpiles, via a combination of contract crushing and screening and owner-operated facilities, would result in an uplift in head grades from 0.4g/t Au to around 0.6g/t Au.
The recommissioning of the mill at Nolans is the first step in the eventual upgrading of the plant to support the overall expansion project, which is expected to take 24 months. Once completed, the expansion project could deliver around 200,000oz of gold annually for 15 years from 2022, Resolute said.
Managing director and CEO John Welborn said: "Increasing the plant capacity at Ravenswood to 5Mtpa and using this capacity to beneficiate and process available low-grade stockpiles, delivers an immediately cashflow-positive, profitable mining operation at Ravenswood.
"More importantly, it is a step towards the much larger production base that we believe is possible at Ravenswood. During 2020, the strategic review will now evaluate the future capital demands of the full REP, contemplate the timing of an investment decision on Stage 2, and how best to maximise value for Resolute shareholders from this potential."