FTI Consulting, the deed administrators of mine owner Wiluna Mining Corporation, appointed Mining One for the study.
The main constraint on the study was keeping the required restart amount viable for a recapitalisation of the balance sheet, given its owner was subject to a Deed of Company Arrangement.
Wiluna slipped into voluntary administration in July 2022.
Creditors approved a deed of company arrangement to allow the company to keep going.
The parameters of the PFS included a production target of 750,000 tonnes per annum of gold ore for production of 67,500 ounces per annum over the 9.5 life-of-mine.
The PFS projected all-in sustaining cost of $2015/oz and estimated $73 million in capital expenditure would be needed.
With a net present value of $198.6 million, payback will be 5.5 years at internal rate of return of 53%.
Over the life-of-mine, free cash flow will be $365 million.
FTI Consulting senior managing director Mike Ryan said the PFS showed there was a potential pathway to bring the Wiluna operations back to a viable footing for a modest amount of capital expenditure.
"As has been demonstrated through multiple resource and reserve statements, Wiluna has a large amount of gold mineral and ore at healthy grades," he said.
"The potential of the 5.24 million ounces of gold contained within Wiluna resources cannot be overlooked."
Ryan said operations around the world with similar refractory ore had produced tens of millions of ounces of gold for more than 30 years by using BIOX processing.
"Unfortunately, the previous operations at the Wiluna gold mine struggled with various operational and financial issues and were unable to properly pursue this potential," he said.
"Having said this, a very significant investment - in excess of $100 million - has been made in Wiluna's recent past in rehabilitating and developing the underground accesses so our next step is to seek parties who are interested in Wiluna's potential."