Leaching behavior and kinetics of vanadium extraction from vanadium-bearing steel slag

Abstract

The vanadium-bearing steel slag as solid waste is also one of valuable vanadium-containing resource. Recovering vanadium from the refractory steel slag is a great challenge in the world. A leaching process study using high concentration sodium hydroxide solution was proposed in this laboratory work. The effects of sodium hydroxide concentration, particle size, leaching temperature and the ratio of alkali to slag on the rate of vanadium leaching were determined and the leaching kinetics was presented. It indicates that the leaching rate is highly sensitive to the sodium hydroxide concentration and leaching temperature and increases with increasing temperature and sodium hydroxide concentration. By studying the reaction mechanisms, it was found that the dicalcium silicate, tricalcium silicate and calcium ferrited which co-exist with calcium vanadate in the vanadium-bearing steel slag were gradually exposed and reacted with NaOH media to form Na3VO4. The leaching kinetics was analyzed which indicated that the leaching rate is controlled by the chemical reaction with the apparent activation energy of 51.34 kJ/mol. On the basis of this process, the vanadium can be effectively extracted with a leaching rate of more than 80%. The leaching medium can be recycled. It is an effective and cleaner process for leaching vanadium.

Microstructure and Mineral Phase Evolution of Vanadium Slag by Modulating the CaO/V2O5 Ratio

“…Vanadium has excellent physicochemical properties and is widely used in steel, aviation, new energy storage devices, and medical fields [1]. Vanadium-titanium magnetite (VTM) is the main occurrence mineral of vanadium resources, contributing more than 88% of vanadium production [2][3][4]. In order to extract as much vanadium as possible, VTM is usually fed into the blast furnace and co-reduced with other metals into molten iron [1,5].…”

Features of the Microstructure and Chemical Compositions of Vanadium-Containing Slags Including Determination of Vanadium Oxidation Degrees

“…Currently, ferrovanadium production technology includes four process stages: the fabrication of vanadium iron, the processing of the iron to a steel semi-product and a converter slag, the fabrication of technical vanadium pentoxide, and the electrical furnace or ladle melting of ferrovanadium [2,3,4,5,6,7,8,9]. There are also other options for vanadium extraction [10,11,12,13,14].…”