Canadian Mining Journal


ENVIRONMENT: Arsenic vitrification may solve Giant mine problem

NORTHWEST TERRITORIES – Dundee Sustainable Technologies (DST) of Montreal says its vitrification proposal is considered the best stabilization and solution for the arsenic dust stored in the former Giant gold mine. The process was examined by the State of Knowledge Review board for Arcadis Canada. It was released on Sept. 11, 2017, on behalf of the Giant Mine Oversight Board (GMOB).

This glass-like product, containing 20% arsenic, can be used to immobilize arsenic dust from the Giant gold mine.. (Credit: Dundee Sustainable Technologies)

The Giant mine operated from 1944 until 2004 producing more than 7 million oz. of gold. The gold in the ore is closely associated with arsenic, and while the mine was in production, 237,000 tonnes of arsenic trioxide dust were collected and stored in 14 underground stopes. The problem now is how to permanently render the material non-hazardous.

DST says its arsenic vitrification (turning it into glass) technology was judged the best of several dozen examined by Arcadis for its ability for long term stability, moderate costs, and potential for gold recovery. The technology has been demonstrated at the laboratory and pilot scale level. The resulting glass contained up to 20.4% arsenic and does not allow the arsenic to leach as measured by the US Environmental Protection Agency’s methodology.

DST is also known for its patented gold recovery technology without the use of cyanide. Please visit