Study On Leaching Behavior Of The Extracted Vanadium Tailings

The extracted vanadium tailings with great production containing heavy metals, such as Cr and V, are the main by-products during vanadium extraction using vanadium tailings as raw materials. These tailings will cause environmental pollution, land occupation and resource waste without effective treatment methods. Therefore, How to reach comprehensive utilization of the extracted vanadium tailings resource has great significance for the rapid development of the vanadium and titanium industries.In this paper, taken extracted vanadium tailings as raw material, the effects of leaching agent types, leaching temperature, particle size of raw material and other process parameters on leaching behavior of the extracted vanadium tailings were studied by XRD and X-ray Fluoreseenee Spectrometry systematically. Under these experimental conditions, the conclusions were obtained as follows:(1) The leaching rates of V and Cr are similar by alkaline leaching process or oxalic acid leaching process. While, alkaline leaching process is more conducive to the enrichment of iron in tailings.(2) Under the alkaline leaching process conditions, the leaching rates of V、Cr and Si firstly increase and then decrease as the concentration of NaOH and ratio of liquid to solid increase. When the concentration of NaOH is40%and the ratio of liquid to solid is5:1, the leaching rates of V、Cr and Si reach the maximum values of58.16%,62.48%and21.24%, respectively.(3) Under the alkaline leaching process conditions, the leaching rates of V、Cr and Si in the extracted vanadium tailings increase gradually with the increasing of leaching temperature and time. When the leaching time reaches60min, the leaching rates of V、Cr and Si in the extracted vanadium tailings have a slight increase.(4) Under the alkaline leaching process conditions, the leaching rates of V and Cr firstly increase and then decrease as the particle size of raw material decreases. When the partical size of raw material reaches75～100μm, the leaching rates of V and Cr reach the maximum values of66.43%and71.04%, respectively. However, the leaching rates of V and Cr increase gradually with the increasing particle size of raw material under the oxalic acid leaching process conditions.(5) The leaching rates of V and Cr firstly increase and then decrease with the increasing of addition amount of H2C2O4(mass fraction ratio of oxalic acid and the extracted vanadium tailings) and leaching time. When the addition amount of H2C2O4reaches0.8and the leaching time reaches60min, then the leaching rates of V and Cr have a slight increase.