Byproduct Uranium Recovered With New Ion Exchange Techniques

In the United States, nearly 200,000 tons of copper are produced annually through the leaching of waste rock and oxidized copper ore using dilute sulfuric acid-ferric sulfate solutions. As part of a study by the U.S. Bureau of Mines, various mining operations in Arizona, Utah, and Nevada revealed that leach solutions often contain uranium in concentrations ranging from 2 to 15 ppm. This raises the potential for uranium recovery during ongoing copper production. Laboratory experiments indicated that uranium could be concentrated effectively through novel ion exchange and solvent extraction techniques. A pilot study was conducted in partnership with Kennecott Copper Corporation, demonstrating that a countercurrent ion exchange system developed from initial laboratory research could efficiently recover uranium from copper waste leach solutions. Results showed that small-scale continuous tests led to the recovery of uranium from solutions with a concentration of 2.42 grams per liter, ultimately producing high-purity U3O8 that met specifications for the nuclear industry. Evaluations of chemical consumption during the extraction process also indicated favourable economics, suggesting the feasibility of large-scale applications for uranium recovery alongside copper production. This development represents a significant advancement in the sustainable extraction of uranium from mining waste.