Highly efficient oxidative-alkaline-leaching process of vanadium-chromium reducing residue and parameters...

Area of Science:

• Metallurgical Engineering
• Environmental Science
• Materials Science

Background:

• Vanadium-chromium reducing residue is a significant solid waste from steel production.
• This residue represents a secondary resource for recovering valuable vanadium and chromium metals.

Purpose of the Study:

• To develop and optimize a highly efficient oxidative-alkaline leaching technology for vanadium recovery.
• To investigate the impact of various experimental parameters on vanadium leaching efficiency.

Main Methods:

• Application of oxidative-alkaline leaching using sodium persulfate (Na2S2O8).
• Systematic investigation of factors: NaOH/Residue ratio, liquid-to-solid ratio, temperature, Na2S2O8/Residue ratio, and reaction time.
• Analysis of leaching kinetics and application of response surface methodology (RSM).

Main Results:

• Achieved 96.3% vanadium leaching efficiency under optimized conditions.
• Identified optimal parameters: NaOH/Residue=0.30, L/S=5 mL/g, 60 min, Na2S2O8/Residue=0.50, 90°C.
• Determined that liquid film diffusion controls the leaching kinetics, with an activation energy (Ea) of 15.57 kJ/mol for vanadium.
• RSM analysis revealed the order of influence for leaching efficiency: NaOH/Residue > Na2S2O8/Residue > temperature > time > liquid-to-solid ratio.

Conclusions:

• The developed oxidative-alkaline leaching technology is highly effective for vanadium recovery from steel industry residue.
• The study provides insights into the key factors and kinetics governing the leaching process.
• This method offers a sustainable approach for resource recovery from industrial solid waste.