Development of a one-step magnet swarf bioleaching process

bar graph shows Bioleaching of metals from milled magnetic swarf by the bacterium Gluconbacter oxydans. Data shown are cumulative metal concentrations in bioleachate from the solid permanent magnet swarf. 1-step indicates biolixiviant production is conducted simultaneously with bioleaching whereas 2-step is biolixiviant production followed by bioleaching.
Bioleaching of metals from milled magnetic swarf by the bacterium Gluconbacter oxydans. Data shown are cumulative metal concentrations in bioleachate from the solid permanent magnet swarf. 1-step indicates biolixiviant production is conducted simultaneously with bioleaching whereas 2-step is biolixiviant production followed by bioleaching.

CMI researchers from Idaho National Laboratory conducted the research for this highlight.

Innovation 
Developed improved metal recycling process by combining biolixiviant production with bioleaching.

Achievement 
Simultaneous production of biolixiviant from municipal solid waste (MSW) non-recyclable paper (NP) with bioleaching of magnet swarf improved metal recovery by 30% (Fig. 1).

Significance and Impact

  • Simultaneous biolixiviant production and bioleaching can decrease capital and operation costs. 
  • Metal recovery increases and new parameter conditions will be evaluated by technoeconomic and life cycle analyses models to determine the economic and environmental impacts of the new process.

Hub Target Addressed 
Sustainable REE recycling from industrial wastes.