Final Environmental Permits for Rodeo Gold ProjectBy Alejandro Ehrenberg | Fri, 11/20/2020 - 14:39
Golden Minerals reported it has received final environmental permits for its Rodeo gold-silver project in Durango. The company is on track to begin gold production in January 2021, which will mark the transition of Golden Minerals to gold producer from precious metals exploration company. “The receipt of the environmental permits for our Rodeo mine puts us on schedule to begin mining in January 2021. We expect to begin delivering gold-bearing material to our Velardeña mill early in January and begin processing immediately,” President and CEO Warren Rehn said in a press release.
The company reported that Rodeo is located approximately 115km from the Velardeña properties. Golden Minerals added that it intends to truck mined material from Rodeo to Velardeña using a commercial trucking contractor. The material will be mined through the company’s existing and newly vacated oxide plant. The plant is a typical agitated leach plant rated to handle up to 450 tons per day of throughput from Rodeo. It is equipped with a Merrill Crowe circuit and a modern doré refinery and the attached tailings facility was recently expanded and is expected to be sufficient for the tailings produced from Rodeo’s operations, the company said.
Golden Minerals has a track record of implementing innovative technology to keep its projects progressing. As described by the company, the Velardeña Properties contain two past-producing underground silver and gold mines and two processing mills. Mining was suspended in November 2015 when a combination of low metals prices, dilution and metallurgical challenges rendered operations unprofitable. Since then, Golden Minerals has leased one of Velardeña’s two mills to Hecla Mining. This lease has provided cash flow that has supported exploration activities.
Golden Mierals has evaluated and tested various mining methods and processing alternatives that could potentially enable sustainable profitable operations at Velardeña. “We recently completed metallurgical testing of pyrite-arsenopyrite flotation concentrates at Velardeña, whereby gold and silver recoveries of over 90 percent were obtained from bio-oxidizing and then cyanide leaching concentrate samples. This so-called ‘BIOX’ technology is owned by Finnish firm Metso Outotec and is in use today at seven mining operations around the world. We look forward to becoming the first company in the North American continent to install and use a BIOX circuit at its operations,” Rehn explained during an interview with MBN earlier this year.
In another interview with MBN, Jan Van Niekerk, Director of Gold Process Solutions at Metso Outotec, elaborated on Rehn’s explanation. “In some gold ores, like at Golden Minerals’ Velardeña deposit, the gold is locked in a sulphide mineral matrix. The gold particles are so small that no matter how finely you grind the ore, you cannot access them with cyanide. Recovery rates become so low that projects cease to be viable, even if there is a lot of gold in the ground. For Velardeña, gold recovery without BIOX was between 5 and 7 percent. With BIOX, this increases to over 90 percent,” he said