The Water Leaching Behavior of Vanadium from a Salt-roasted VTM Concentrate and the Preparation of High-concentration Vanadium Solution

This study investigated the water leaching behavior of vanadium in Na2CO3-roasted vanadium-bearing titaniferous magnetite (VTM) concentrate. The magnetic concentrate and Na2CO3, mixed in a mass ratio of 4:1, were roasted at 1050 °C, kept for 3 h, and ground to a size of D50 = 48.79 μm using a rod mill. The effects of leaching temperature and pulp density on water leaching were then investigated. The results show that the vanadium leaching efficiency decreased to 90.4%, 88.2%, and 83.8% as the temperature increased to 25, 55, and 85 °C, respectively, whereas it remained almost constant 90.4%, 87.0%, and 87.0% as the pulp density increased to 10, 50, and 100 w/v%, respectively. Based on the preliminary leaching results, multi-stage leaching was conducted with the experimental conditions of 25 °C, 100 w/v%, 300 rpm, and 1 h. The vanadium concentration in the final leaching solution was determined as 16.20 g/L after four stages of leaching. Thus, a high-concentration sodium vanadate solution was prepared by multi-stage leaching.