从云母型含钒石煤中酸浸钒、铝的动力学

Kinetics on Leaching of Vanadium and Aluminum From Vanadium-containing Mica Type Stone Coal

采用“核收缩”模型研究了湖北某地含钒石煤硫酸浸出过程中钒、铝的浸出动力学。结果表明，钒的浸出动力学过程与钒的转价有密切关系：在25～45℃条件下，浸出初期，钒的浸出以五价钒及颗粒表面四价钒为主，受化学反应控制，表观反应活化能为36kJ／mol；浸出后期，反应界面向颗粒内部推移，钒的浸出转化为内扩散控制，以四价钒为主，表观反应活化能升高为64kJ／mol。在55～95℃条件下，三价钒亦被活化，钒的浸出过程受内扩散控制，表观反应活化能最高，为91kJ／mol。铝由于赋存状态单一，始终受晶格束缚，其浸出动力学过程受内扩散控制，表观反应活化能较高，为68kJ／mol。钒、铝浸出均为二级反应，对硫酸浓度依赖性较大。

The kinetics on leaching of vanadium and aluminum using sulfuric acid from the vanadium‐bearing stone coal was investigated by shrinking core model .The results indicate that the leaching kinetics of vanadium interrelate with the valence of vanadium .At 25 -45 ℃ ,the leaching process of vanadium is controlled by chemical reaction with the apparent activation energy of 36 kJ/mol ,and the vanadium leached mainly consist of V （Ⅴ ） and V （Ⅳ ） on the particle surface at the initial leaching stage .At the late leaching stage ,the reaction boundary moves into the inside of particles ,and the leaching process of vanadium which is mainly V （Ⅳ ） is controlled by internal diffusion with the apparent activation energy of 63 kJ/mol .At 55-95 ℃ ,V（Ⅲ） is activated and the leaching process of vanadium is controlled by the internal diffusion with the apparent activation energy of 91 kJ/mol .The leaching process of aluminum is controlled by the internal diffusion because it only occurs in lattice bound ,with the apparent reaction activation energy of 68 kJ/mol .The leaching rate of vanadium and aluminum rely on greatly the sulfuric acid concentration and their leaching processes both are second‐order reaction .