Nontoxic Formula Extracts Precious Metals from E-Waste

By Paul Ploumis (ScrapMonster Author)

August 12, 2016 10:26:26 PM

SEATTLE (Scrap Monster): Mineral processing company Mineworx says it has developed a nontoxic leach formula that extracts precious metals from ores and e-waste that is safer for the environment than existing cyanide-based formulas.

Mineworx’s parent company, Canadian mining firm Iberian Minerals, has created a new subsidiary, HMX Solutions, to pursue commercial opportunities for the HM X-leach formula.

Mineworx’s formula is made of food-grade, organic ingredients and is recyclable, Resource Recycling reports. In a test performed on e-waste scrap, HM X-leach accumulated 2,600 parts per million of gold in the solution in less than an hour of soaking. Mineworx CEO Duane Nelson told Resource Recycling the formula matches cyanide’s recovery rate of 97 percent in about four hours.

Cyanide is the dominant leaching agent used in gold processing. But it creates toxic wastewater and is a relatively slow in recovering the precious metal and has been banned in some US states, European countries and South American countries.

While other chemicals have been tested to leach gold, Mineworx says none have been more cost-effective and productive than cyanide until now.

The HM X-leach solution recovers gold and other precious metals through several extraction methods including electrowinning, carbon absorption and precipitation.

“We are very excited with the results of the HM X-leach formula,” said Nelson in a statement. “It has been proven by independent analysis to be non-toxic and faster than typical cyanide solutions on a number of different ores, concentrates and tailings. The HM X-leach is safer to use, offers faster dissolution rates and offers much broader operational parameters.”

Nelson says the nontoxic formula will help to reduce the risks and environmental impact of mineral processing, which “may open up opportunities in areas where the use of cyanide is banned.”

Mineworx, which filed a US patent for its HM X-leach formula last month, isn’t the only one developing nontoxic alternatives to recovering gold from ores and e-waste. As Waste Dive reports, earlier this year researchers at the University of Saskatchewan in Canada found another alternative that uses acetic acid and an oxidant.