Co-extraction of vanadium and chromium from vanadium-chromium-bearing reducing slag via oxygen microbubbles intensified copper oxide catalytic oxidation method in alkaline solutions

Vanadium-chromium-bearing reducing slag (VCRS) is a hazardous waste that contains heavy metals like va-nadium (V) and chromium (Cr). If not handled properly, it could cause an ecosystem disaster. Here we introduce a new process using copper oxide (CuO) catalytic oxidation intensified by oxygen microbubbles to recover V and Cr from VCRS. Electron paramagnetic resonance (EPR) was used to examine the generation of superoxide rad-icals (HO2 & sdot;/O2 & sdot;-) and their effect on the oxidation of V and Cr. The amount of HO2 & sdot;/O2 & sdot;- was directly related to the CuO catalyst and oxygen microbubbles, and the V and Cr oxidative leaching process was dependent on the amount of HO2 & sdot;/O2 & sdot;-. We achieved an effective recovery of V and Cr at 110 degrees C under atmospheric pressure, and the V and Cr leaching efficiencies were 98.1 % and 98.5 %, respectively, using 50 wt% NaOH solution. This approach is a promising alternative method for the clean treatment of VCRS.

Automated summary

In this study, a new process using copper oxide catalytic oxidation intensified by oxygen microbubbles was introduced for the recovery of V and Cr from VCRS. The generation of HO2⋅/O2⋅- and its effect on the oxidation of V and Cr were examined using EPR. The amount of HO2⋅/O2⋅- was directly related to the CuO catalyst and oxygen microbubbles, and the V and Cr oxidative leaching process was dependent on the amount of HO2⋅/O2⋅-. An effective recovery of V and Cr, with leaching efficiencies of 98.1% and 98.5%, respectively, was achieved at 110 degrees C under atmospheric pressure using 50 wt% NaOH solution. This approach offers a promising alternative method for the clean treatment of VCRS.