Environmental Aspects of the Electrochemical Recovery of Tellurium by Electrochemical Deposition-Redox Replacement (EDRR)

The current study investigates the energy consumption and the corresponding global warming potential (GWP) of tellurium recovery from multimetal solution by the use of a tailored electrochemical recovery approach based on electrodeposition-redox replacement (EDRR). A three-electrode cell was used to recover Te from synthetically prepared pregnant leach solution similar to the PLS of leached Doré slag (30% aqua regia, [Cu] = 3.9 g/L, [Bi] = 4.6 g/L, [Fe] = 1.4 g/L, and [Te] = 100–500 ppm). The enrichment of Te on the electrode (with 100 EDRR cycles) had a calculated global warming potential of 3.7 CO₂ -eqv from a solution with 500 ppm Te based on a Finnish energy mix. In comparison, a decrease of Te concentration to 100 ppm increased the corresponding environmental impact to 16.9 CO₂ -eqv. Overall, GWP was shown to be highly dependent on the geographical area, i.e. the dominating energy production methods.