Effect Of Mechanical Activation On Mineral Properties Of Stone Coaland Its Vanadium Leaching Process

Stone coal containing vanadium is a kind of important strategic resources andextraction vanadium from stone coal is an important way to improve thecomprehensive utilization of vanadium resources. In the process of vanadiumextraction from stone coal, leaching is a key step, from which largely determines thetotal recovery rate of the whole process. Therefore, strengthen leaching process hasimportant significance for hydrometallurgy.Mechanical activation is one of the important pretreatment to strengthen themineral leaching embarks. This paper took cone ball mill of XMQ-Φ240×90,porcelain mill of XMCQ-Φ280×290and rod mill of XMB-67200×240to implementmechanically activation on roasted stone coal. Througn systematic study effect of theactivation time, activation medium and activation facility on the leaching behavior ofstone coal in sulfuric acid solution system as well as investigating the changes of sizedistribution, surface morphology, crystal structure, thermal behavior and otherphysicochemical properties before and after mechanical activation of sample withdetection methods of specific surface area (BET), scanning electron microscopy(SEM), X ray diffraction (XRD), infrared spectroscopy (FTIR), thermo gravimetricanalysis and differential scanning calorimetry (TG-DSC), preliminary exploring themechanism of enhancing vanadium leaching process by mechanical activation.The results indicated that, mechanical activation had a stage effect on leaching.Prolonging activation time, changing the activation medium and activation device,leaching rate of vanadium showed a trend which first increased then decreased.Respectively using XMQ-Φ240×90conical mill and XMCQ-Φ280×290asapparatus, both taking air as activation medium could obtain a better effect. Whensulfuric acid concentration was3mol/L, liquid to solid ratio was1.5ml/g, the stirringrate was400r/min, the dosage of CaF2was5%of the mass of the sample, temperaturewas98℃, leaching for6h,the highest extraction rate were distinguishly80.06%and80.21%; Compared with non activated67.38%, after mechanical activation, theleaching rate of vanadium had greatly been improved.Analysis on physical and chemical properties of samples before and after showedthat, after mechanical activation, particle size refined and specific surface areaincreased. Meanwhile, the surface energy increased and the crystal lattice was destroyed as well. These changes made the samples with high activity, so as toimprove leaching rate and reduce apparent activation energy and reaction order.