Synergetic strengthening mechanism of ultrasound combined with calcium fluoride towards vanadium extraction from low-grade vanadium-bearing shale

The effect and mechanism of ultrasound and CaF2 on vanadium leaching from vanadium-bearing shale were investigated systematically. In consideration of the enhancement for vanadium recovery, the combination of ultrasound and CaF2 (66.28%) exerts more evident effects than ultrasound (26.97%) and CaF2 (60.35%) alone, demonstrating the synergetic effect of ultrasound and CaF2. Kinetic analysis manifests that the product layer diffusion controls...