Mobile Navigation

Chemical Engineering

View Comments

Increasing recovery of metals from refractory mine tailings

| By Gerald Ondrey

EnviroGold Global Ltd. (Toronto, Ont., Canada; www.envirogoldglobal.com) has filed a patent application for a proprietary electrochemical process designed to achieve advanced metal recoveries from refractory ores with reduced capital expenditures (capex) compared to industry standard solutions.

“The residual metals contained in tailings are commonly encapsulated in refractory ores, and it is estimated that the value of precious metals currently locked up in tailings storage facilities and old mine sites exceeds $1 trillion, increasing by $20 billion/yr,” says Mark Thorpe, EnviroGold Global’s CEO. “Further, as the proportion of refractory gold reserves continues to increase globally, we believe the ability to achieve advanced metal-recovery rates and attractive economics from the processing of refractory ores provides better environmental outcomes, expands the company’s addressable market and creates an enduring, competitive advantage.”

“Refractory ores resist conventional metal extraction due to an impervious mineral matrix surrounding super-fine metal particles,” explains chief technology officer Brock Hill. “The complex processes required to significantly improve extraction from these ores can drive substantial increases in a project’s capex and opex (operating expenditures), often rendering otherwise attractive resource recovery opportunities uneconomic. EnviroGold Global’s patent-pending process is designed with advanced electrochemical technology to induce changes in the metal-bearing matrix and achieve superior metal-recovery rates,” he says.

This process, in conjunction with other proprietary solutions developed for the removal of environmental contaminants, including cyanide, allows EnviroGold Global to provide a compelling value proposition for mine site owners while reclaiming and recharging natural resources, the company says. (For more on electrochemistry, see the Newsfront on pp.12–16.)