Abstract: Relationships between leaching time, leaching temperature, H₂SO₄ initial concentration and residual acid concentration of leaching solution were studied, leaching pulp potential changes in leaching process were investigated. Results indicate, residual acid concentration of leaching solution don't vary with leaching time or leaching temperature, and the H₂SO₄ consumption in acid leaching process account for about 66% of the initial H₂SO₄ amount; pulp potential decreases from 610 mV to 480 mV after leaching for 4 h, and have no more changes when vanadium leaching rate reaches balance.

Key words: Stone coal, Vanadium, Acidity, Electric potential