Improved recovery of tellurium from spent CdTe photovoltaics

CMI researchers at Idaho National Laboratory conducted the research for this highlight

Innovation 
Novel bench-scale cation-exchange (CX) chromatographic purification followed by recovery via electrowinning (EW) isolates Te metal with efficiency and performance superior to standalone EW of electrochemically-generated (EC) leachate of spent CdTe PVs.

Achievement

  • EC leachate of CdTe PVs contains Te in <50% purity. Direct EW of EC leachate isolates Te with only ~70-80% purity but in ~8-10 h.
  • CX chromatography using Amberlite resin removes interfering metal impurities (Cd, Cu, Se, Al, etc.) from EC leachate, achieving >98% Te purity in ~15 min even at >20x larger scale (preparative). 
  • EW of the purified EC leachate isolates Te with >98% purity in <1 h.

Significance and Impact
Higher purity (>20%) of Te and faster operation (>8x) will reduce cost and increase sustainability of Te isolation from spent CdTe PVs.

Hub Target Addressed 
Process intensification to improve material & manufacturing efficiency.

Figure: Bench-scale development of Te recovery and isolation process from spent CdTe PVs via sequential EC leaching, CX chromatography, and EW.
Figure: Bench-scale development of Te recovery and isolation process from spent CdTe PVs via sequential EC leaching, CX chromatography, and EW.