Goodbye Cyanide, Hello Mystery Process

Desert Mineral changes plan at Blacks Creek mine


After a long and contentious public comment process, Desert Mineral Mining received a permit last spring to build a cyanide-leaching gold mill 20 miles east of Boise. Now the company has decided to abandon the cyanidation process, opting for an obscure mining technique that will allow them to process a far greater amount of ore than they were previously allowed--and with a fraction of the governmental oversight.

Desert Mineral CEO Dan Terzo told BW his company has long had plans to use sodium bromide rather than cyanide but only recently decided to change course. He said sodium bromide has been used "pretty much worldwide," but that it hadn't been done efficiently enough to be profitable until Desert Mineral's sister company has "perfected" a process which will allow the company to mill the gold, as well as clean up old mining waste, without any toxic remainders. "You can just spread it over the ground," Terzo said of the waste from sodium bromide mining. "It's purer than what's going in."

Originally, the company applied to the Idaho Department of Environmental Quality for a permit to process over 120,000 tons of ore through a cyanide leaching process. By the time the company received the permit, the DEQ had reduced the permitted amount to 22,000 tons. However, since sodium bromide mining is not recognized or regulated by the DEQ, those restrictions will be moot if Desert Mineral moves forward with its plan. Terzo said the company could now "possibly" process around the amount of ore they had originally intended.

"One of the advantages of us going to bromide is we won't have those type of restrictions," Terzo said.

But is the process as harmless as Terzo says? Bruce Schuld, mining project coordinator at the DEQ, said his agency doesn't know, and has no recourse to find out. "They haven't given us anything on it, and without a regulatory hammer, we can't require them to," he said.

The public will also be kept in the dark, at least until the Idaho Department of Lands releases the mine's new site restoration plan for public comment. Eric Wilson at IDL said he had still not received several documents from Desert Mineral, and he could not put a timeline on when the document would be made available.

In any event, since the company is not planning to use their permit, Schuld said, the approximately $38,000 that the DEQ spent developing it will likely end up a waste. He said he will use the company as an example when he speaks to the Idaho legislature this month to ask for approval of a new rule system that demands greater financial liability on companies applying for cyanidation permits.

"These were frivolous requests," Schuld said of Desert Mineral and another aborted cyanide operation. "I'm going to make clear that we could have used these funds to apply to our work in other areas."