Acid Leaching of Vanadium from a Vanadium Residue

Abstract

A process has been developed at the laboratory scale for leaching of vanadium from a vanadium residue using mixed hydrofluoric and sulfuric acid solutions, and NaClO as an oxidant. The extraction studies were carried out using various acid concentrations, liquid/solid ratios, addition of oxidant, reaction temperatures and leaching times. The optimum leaching conditions were then determined. Characterization of the leach residues was carried out by SEM and EDS analysis. Results indicate that the silicates can be effectively destroyed by HF, and the vanadium contained in the vanadium-iron spinel can be leached by the mixed acid solutions. The addition of NaClO enhanced the leaching process by the oxidation of V3+(s) to V4+ and V5+. The leaching efficiency was also improved by raising the leaching temperature, prolonging the reaction rime and using a higher liquid/solid ratio. A vanadium recovery of 81.8% was obtained by the direct acid leaching process

The Production and Utilization of Two Smelting Processes for V-Ti Magnetite

“…Extracting vanadium from the vanadium slag generally contain the hydrometallurgy process of roasting, leaching, solvent cleaning and vanadium precipitation [15][16][17] . The main process of extracting vanadium used in industry are: (1)acidleach-alkali dissolution process; (2)sodium salt roasting process; (3)calcified roasting process; (4)solvent extraction method; (5)ion-exchange process [18] .…”

Two Potential Ways of Vanadium Extraction from Thin Film Steelmaking Slags

“…Existing technologies to remove vanadium from the slags-direct acid leaching [3][4][5][6][7][8], sodium salt roasting [9][10][11], hot slag reduction [12], and bioleaching [13]-have their advantages and limitations, and the choice of technology depends on different factors including economic and environmental considerations. The sodium roasting-water leaching method is the most commonly used one to extract vanadium from V-bearing slags [14], but at the same time it presents several environmental challenges, including (1) decomposition of sodium salts creates harmful gases such as HCl, Cl 2 , SO 2 , SO 3, and CO 2 [15], which pollute the air and damage equipment used in the extraction process; (2) wastewater generated during extraction has high concentrations of sodium and ammonium sulfates, making it difficult to reuse [16]; (3) the resulting leaching residues have a high sodium content, making them unusable and unsuitable for recycling because sodium corrodes the lining of blast furnaces and converters; (4) water leaching residue contains 1-3% of V 2 O 5 which is currently turning into waste [17]. This results in the accumulation of leaching residues, which consume valuable land resources [18].…”

“…Bioleaching is based on the capability of certain microorganisms to transform solid compounds into extractable, water-soluble forms. However, it also has drawbacks including (1) bacterial leaching occurs very slowly (often taking several months) and cannot be quickly halted once initiated, unlike other methods; (2) the heat produced during the dissolving process can be fatal to the microorganisms involved; (3) large open spaces for treatment procedures are required; (4) high risk of contamination.…”

Vaporization of Vanadium Pentoxide from CaO-SiO2-VOx Slags During Alumina Dissolution

“…[6] Further, vanadium is an important element for Ti-6Al-4V alloy widely-used in additive manufacturing. [7] Several methods to recover vanadium have already been reported as for example, direct acid leaching, [8] sodium salt roasting, [9] hot slag reduction, [10] and bioleaching. [11] During vanadium extraction, the disadvantages such as large amount of waste after leaching, high salt consumption at roasting, and substantial energy consumption during hot slag reduction make those methods energy-inefficient, expensive, time consuming, and environmentally polluting.…”