Flue dusts yield to simple leaching strategy for indium and copper

CMI researchers at Colorado School of Mines conducted the activity for this highlight

Innovation 
Domestic copper smelting can supply significant quantities of indium. 

Achievement
A hydrometallurgical leaching method affords a separation of bulk copper content from the majority of the indium.

Significance and impact

  • The US is 100% reliant on imports of indium for displays & solar panels.
  • Traces of indium in copper ore are concentrated in smelter flue dust.
  • Partner Rio Tinto Kennecott Copper can potentially produce 9 tpa of indium at its Utah smelter in Utah, offsetting 110 tpa domestic imports.
  • Indium resists simple leaching, which releases bulk copper, resulting in a separation that can be followed by indium purification steps.

Hub target addressed 

Industry adoption of a technology for domestic supply of a metal other than rare earths or lithium. CMI grand challenge dealing with recovery of critical materials from dilute and unconventional sources.

Potential flow sheet for electrostatic precipitator  dust leaching. Estimated recoveries are shown to right of each element. 
Potential flow sheet for electrostatic precipitator  dust leaching. Estimated recoveries are shown to right of each element.