Study on the Grinding Kinetics and Magnetic Separation of Low-Grade Vanadiferous Titanomagnetite Concentrate

Abstract

In recent years, a low-grade vanadiferous titanomagnetite concentrate (LVTC) produced in the northwest area of Liaoning has attracted more and more attention. However, it is difficult to recover and utilize valuable minerals such as iron, titanium, and vanadium, due to their special physical and chemical properties and complex mineral composition. Grinding and magnetic separation are two important operational units for recovering valuable metal components from vanadiferous titanomagnetite. Therefore, the grinding kinetics of the LVTC in northwestern Liaoning were first studied by means of grinding kinetics equations in this paper. The results show that the grinding process of LVTC is consistent with the grinding kinetics equation, and the sieve residues of particles approached a constant value after grinding for 30 min, resulting from equilibrium between the fragmentation and agglomeration processes. In addition, equivalent particle size (EPS) and specific surface area (SSA) were linearly proportional to the double logarithm of grinding time, and the correlation coefficients for fitted data by the Rosin–Rammler–Bennet (RRB) model were slightly higher than those by the Swebrec model, and could reflect the dispersibility and uniformity of particle size distribution (PSD) quantitatively. Then, the grinding products were separated by magnetic separation, and the influence of grinding conditions on the grade and recovery ratio of Fe and TiO2 in the LVTC was analyzed. As a result, grinding time has a significant impact on the recovery ratio and grade of Fe and TiO2 during the magnetic separation process, and the LVTC grinding duration is not as prolonged as it might be, as the optimal grinding time is 20 min. Titanomagnetite, ilmenite, and titanite are still the predominant phases in all magnetic separation products at optimal grinding time, but the intensity or content of these three minerals varies between magnetic separation products, and 232 kA/m magnetic field intensity has a higher separation efficiency than 134 kA/m magnetic field intensity.