High efficiency extractions of V, Cr, Ti, Fe and Mn from vanadium slag by microwave heating

Abstract

The vanadium slag (V-slag) is generated from smelting vanadium titanomagnetite ore, which contains valuable elements, such as V, Ti, Cr, Fe, and Mn. The traditional methods were mainly focused on the extractions of V and Cr by oxidation or reduction processes. In the present work, chlorination method was adopted to keep the valence state of each element in original state. In order to speed up the diffusion of elements and reduce volatility of molten salt, microwave heating was examined in the current paper. The results indicated that it only took 30 min to chlorinate V-slag at 800 °C, and the chlorination ratios of V, Cr, Mn, Fe, and Ti reached to 82.67%, 75.82%, 92.96%, 91.66%, and 63.14%, respectively. Compared with the results by conventional heating for 8 h, this extraction rate by microwave heating showed greater advantages. In addition, microwave heating effectively reduced volatilization of AlCl3 by shortening the reaction time. The volatilization ratio of AlCl3 in this microwave heating was 3.92% instead of 8.97% in conventional heating (1h). The mechanism of efficient chlorination can be summarized as the enhancement of ions diffusion process and enhanced chemical reaction due to local high temperature.

Keywords

• vanadium slag
• microwave heating
• molten salt
• high efficiency chlorination