Leadville Mill owners drop cyanide from plans to process mine waste in search for gold

Nick Michael knows even the word “cyanide” fuels a sense of foreboding. It’s the poison deployed by villains in all kinds of movies. It’s also a hard-to-handle toxin used across the world for extracting precious metals from ore. 

“I’ve been in the mining industry my whole life and there’s no avoiding the cyanide question,” Michael said. “It stirs a lot of emotions.”

Michael didn’t want to use cyanide in his controversial plan to extract tiny bits of silver and gold from thousands of tons of mine waste piled around Leadville. 

“It wasn’t our first choice. But it’s so hard to avoid,” he said. 

Then he and his partners at the 43-acre CJK Milling project on the edge of Leadville found Extrakt Process Solutions, which offers an untested possibility that could allow Michael to extract gold from mine dumps around the city without using the decades-old sodium cyanide leaching technique that leaves dangerous waste in lined tailings ponds. 

“This stuff is pretty environmentally friendly, from what we understand,” Michael said of Extrakt’s patented chemical process. “It breaks down. It doesn’t leave remnants. No one has a crystal ball and it’s a very new technology, but it’s really exciting. Our preliminary leach testing results are incredible. We are practically ending our process with drinking water quality on some of these early tests.”

The proposal to fire up the dormant Leadville Mill in the California Gulch tributary of the Arkansas River has galvanized a vocal group of Lake County citizens who are urging the state to deny approval for the reclamation project. 

Michael has a pending application with the Colorado Department of Reclamation, Mining and Safety that would allow him to truck as much as 140,000 tons of ore a year from mine waste dumps piled at dozens of locations around Leadville to the mill he and his partners bought in 2008. The mill has a 2014 permit from the state to process a smaller amount of ore using a different method. The investors behind CJK Milling are asking the state to amend the mill’s reclamation permit to increase the amount of ore it can process using cyanide leaching. The CJK Milling plan does not include mining ore, but gathering it for processing.

Locals in the headwaters of the Arkansas River are wary of a return to mining in a growing community that has spent decades working to mitigate the damage from the hundreds of silver, lead and zinc hardrock mines that dot California Gulch. They are not keen to see dozers disturbing slag piles that have been remediated and trucks hauling that mine waste across town. 

First ever commercial use of new chemical process 

In the 1980s the Environmental Protection Agency designated the mine dumps around Leadville as a Superfund site, launching a more than 50-year cleanup project. The EPA’s sixth five-year review of the California Gulch Superfund site found that decades of work to clean runoff flowing from miles of mine tunnels across the 18-square-mile site has prevented hundreds of tons of cadmium, lead, copper, manganese, iron and zinc from flowing into the Arkansas River every year. The work also cleaned soil and reduced the community’s exposure to metals left over from more than 140 years of mining. More than 90% of the cleanup of the thousands of mines around Leadville has been completed.

“All those EPA protections are working. We are protective of our historic heritage in Leadville and mining is our heritage,” said Ruth Goltzer with the Concerned Citizens for Lake County group that is scrutinizing the CJK Milling proposal. Goltzer noted that the plan to remove slag piles on the east side of town is inside a National Historic Landmark District. “We have so many questions.”

Goltzer said her group is not opposed to industrial operations around Leadville. They want to learn more about the Extrakt process and what it means for the CJK Million permit application. Will they withdraw that application and file a new one? Will they revise their existing application for a fourth time?

The Colorado Division of Mining, Reclamation and Safety has not reviewed any information about the Extrakt technology or its chemical process and declined to speculate. A division spokesman said state staffers reviewing the permit application filed by CJK Milling will have to evaluate the new plan before deciding if Michael and his team will need to submit a new application or simply revise the already submitted paperwork. 

Michael said his operation could be the first to put Extrakt to a commercial use. The Kentucky-based company’s website details how the technology has worked to clean oil spills and filter clean water out of contaminated tailings ponds. Extrakt and global engineering giant Bechtel have partnered on the new solid-liquid separation technology called TNS. Emails to Extrakt were not answered. 

Michael said CJK Milling will need to revamp its plans for the closed Leadville Mill property. That includes updating the design of the plant and its equipment as well as changing the footprint of the operation. He is waiting for a third-party lab’s results from tests using the Extrakt chemical process on samples of slag collected around Leadville. 

“Look, we know this thing will be vetted six different ways to Sunday and we are ready to lead on what we think is a ground-breaking new technology,” Michael said.

The plan isn’t making sense for Steven Emerman, an expert in protecting watersheds from mine tailings who authored a 113-page report in July for the Concerned Citizens of Lake County group outlining 29 areas where the Leadville Mill project proposal falls short. Replacing cyanide only addresses three of his concerns, which largely focused on impacts to water quality and supplies in the headwaters of the Arkansas. 

“So the Extrakt process removes all the metals from the crushed rock? Gold, silver, copper, iron, cadmium, lead, mercury, everything?” Emerman said in an email. “So then we end up with a mass of every metal that was contained within the old mine waste? How are gold and silver extracted from the mass of all metals? And once the gold and silver are extracted, what will be done with the metals that are left behind? Many of those metals will be toxic to both humans and aquatic life.”

Michael knows he’s got a long row to hoe to prove the new technology. He’s hoping Colorado lawmakers will help. 

The year-round Water Resources and Agriculture Review Committee in September drafted legislation — Bill C,  or the Legacy Mining and Modernization Act — that would amend the Colorado Mined Land Reclamation Act to expedite a new type of state permit for reclamation projects at the more than 23,000 abandoned mines around Colorado. 

The legislation notes that current law can challenge cleanup work “due to stringent regulations that are geared to address mining operations, not reclamation only.” The new state permit “should be created to remove undue regulatory burdens and facilitate the removal of waste piles while providing regulatory oversight and ensuring lands are returned to beneficial use,” reads the draft legislation the committee forwarded for consideration in next year’s session. 

“It is difficult to get a reclamation permit. We are un-scarring the land,” Michael said. “We are doing the opposite of what the regulations are written for and this new legislation and a new permitting process that is coming out could really help remove all this mining waste.”