A 261,000-ton stockpile of arsenic dust kept frozen in chambers up to 250 feet down at the edge of Yellowknife has given researchers a sample they turned into arsenic metal more than 99 percent pure, out of waste that would fill seven 10-story buildings

A 261,000-ton stockpile of arsenic dust kept frozen in chambers up to 250 feet down at the edge of Yellowknife has given researchers a sample they turned into arsenic metal more than 99 percent pure, out of waste that would fill seven 10-story buildings