Proceeds from the financing will fund the company's ongoing pilot production initiative with ALS Global, at its piloting facilities in Perth, Australia, and provide additional working capital.
The pilot programme is focused on optimisation of the company's refractory ore technology ahead of this year's commercial metal production implementation at the company's Australia project and is scheduled for completion in March 2023.
Refractory ores are complex and particularly difficult to process for the recovery of metals, which are entrained as sub-microscopic particles inside the lattice of pyrite and arsenopyrite, primarily. Other processes used to recover metals in refractory ores utilize high heat (roasting), high pressure, long acid residency times, ultrafine grinding, or expensive, specialized equipment.
EnviroGold Global says its NVRO Process operates at atmospheric pressure, relatively low heat using an exothermic reaction, and does not necessarily require fine grinds to optimize gold and silver recovery. It uses a two-stage acid leach with short, one-hour acid residency times in which the acid is a catalyst, and therefore little of the acid is consumed in the reaction. An acid recycling circuit serves to help further minimize costs.
The process also neutralizes the acid-forming potential of the pyrites in refractory ore. This eliminates legacy environmental liabilities from existing tailings as well as new ore streams, offering owners with potentially acid-forming projects and waste stores an ESG and cost-savings opportunity.
"Following the completion of our proprietary leach, almost 99% of the original pyrite is oxidized and can then be neutralized to ferric oxyhydroxide—mineralogically goethite—which is inert and non-acid generating", said the company in October 2022.
EnviroGold Global will first apply the NVRO Process to refractory material at the Company's Hellyer Tailings Project, where independent analysis from the Company's flowsheet development partner, Core Resources, has demonstrated gold recovery rates >80% and silver recovery rates >90% for total project after-tax free cash flows of US$ 350M
The announcement comes after the company said earlier this year that results of Phase 1 of the Hellyer Tailings Reprocessing Project, at the Hellyer Gold Mine, Tasmania, Australia, are expected in early 2023 and will be a key milestone to deploying a full-scale pilot program as a precursor to plant engineering and construction there.
