Efficiency and mechanism of vanadium extraction from vanadium-bearing metallurgical waste slag by using self-heating acid curing and normal temperature water leaching

The self-heating acid-curing and normal temperature water leaching process was used to extract vanadium from vanadium-containing metallurgical waste, and the optimal process parameters and mechanism of vanadium extraction were analyzed. The research results showed that when the dosage of concentrated sulfuric acid was 70% of the raw material, the aging time was 3 h, the particle size of the raw material was -0.6 mm, the leaching liquid-solid ratio was 4:1, and the leaching time was 1.5 h, the leaching rate of vanadium in the raw material was as high as 99.1%, the grade of V2O5 in the leaching residue was only 0.09%. The results of vanadium leaching kinetics showed that the leaching process was conformed to the unreacted shrinking core model, and was controlled by solid film diffusion, the reaction activation energy was 16.9 kJ/mol. The advantage of this process was that the reaction was carried out at room temperature. The leaching solution was enriched and purified to prepare high-purity V2O5 products, and the washing solution was used to leach the slag after being cured by concentrated sulfuric acid, so as to realize the recycling of resources.