石煤提钒焙烧过程钒的价态变化及氧化动力学

Valence Variation and Oxidation Kinetics of Vanadium during Vanadium-bearing Stone Coal Roasting

含钒石煤是我国重要的钒矿资源,钒的焙烧氧化是石煤提钒的基础。以湖北某地钒矿为研究对象,首先采用电位滴定对氧化焙烧过程中钒的价态变化进行了研究。在此基础上,探索了钒氧化过程中控制反应速率的步骤,测定了动力学参数——表观活化能。研究表明,石煤中钒主要赋存在伊利石中,焙烧过程中钒的氧化过程是逐级氧化过程(V(Ⅲ)→V(Ⅳ)→V(Ⅴ)),钒的氧化反应属扩散动力学控制,其动力学表观活化能为E1=81.19 kJ/mol。

Vanadium-bearing stone coal is an important vanadium resource in China, and the roasting and oxidation of vanadium is the foundation for extracting vanadium from stone coal. Firstly, the valence variation of vanadium in oxidation roasting of the vanadium-bearing stone coal from Hubei province was studied by potentiometric titration. On this basis, the control reaction step of vanadium oxidation process was presented, and the related dynamic parameter-apparent activation energy was measured. The results show that occurrence of vanadium in stone coal is mainly in illite, the oxidation process of vanadium is stagewise process （Ⅴ（Ⅲ）→Ⅴ（Ⅳ）→Ⅴ（Ⅴ））, and its oxidation reaction is controlled by diffusion kinetics whose dynamic apparent activation energy is E1= 81.19 kJ/mol.