Extraction Of Vanadium Research Articles

Solid-state reaction of a CaO-V2O5 mixture: A fundamental study for the vanadium extraction process

Solid-state reaction of a CaO-V2O5 mixture: A fundamental study for the vanadium extraction process

Assessment of population balance approach and maximum entropy on drop size behavior of vanadium extraction from sulfate solution in continuous pilot plant column

The present study develops comprehensive drop size distribution by coupling numerical modeling with experimental data to optimize the heavy metal extraction in a modified rotating disc contactor column. Droplet behavior was illustrated based on the maximum entropy principle, population balance model, normal and log-normal functions. For case studies, the vanadium extraction from sulfate solution by mixtures of D2EHPA and TBP extractants and metal stripping from the loaded organic phase by ammonium solution was employed as the reactive agents to generate chemical reactions. The modeling results indicated that the agitation speed and mass transfer direction have more profound influences on the drop size distribution, whereas only partially associated with the phase flow rates. Mathematical optimizations based on the Lagrange multipliers method are conducted to formulate the new correlations in terms of the maximum entropy principle (MEP). The population balance model (PBM) was utilized to characterize the distribution internal coordinate with main parameters in the breakage and coalescence of drops. From output results for drop size distribution, the population balance approach validated significantly with the experimental data for reactive systems in an MRDC column.

A clean metallurgical process for vanadium precipitation from chromium-containing vanadate solution

The conventional process of sodium carbonate roasting-water leaching for vanadium extraction cannot be applied to high chromium bearing vanadium slag, and the production process will produce a large amount of V-Cr-bearing reducing slag and wastewater containing sulfate and ammonium salt. To avoid these questions, this work proposes a novel process for the extraction of vanadium and chromium from vanadium slag. In the current research, the vanadium precipitation part of the novel process was studied in detail. The experiment results show that weak basic ammonium bicarbonate precipitation method can realize the selective precipitation of vanadium from chromium-containing vanadate solution. The presence of Cr(VI) in the solution has a great influence on precipitation, crystallization as well as product purity of NH4VO3. Chromium can increase the solubility of NH4VO3 and reduce the supersaturation degree of NH4VO3. Furthermore, it can change the crystal morphology of NH4VO3 and affect the precipitation of NH4VO3. The precipitation of NH4VO3 increased with the increase of N/V molar ratio, but decreased with the increase of chromium concentration in the solution. The content of chromium in V2O5 increased with the increase of N/V molar ratio as well as the chromium concentration in solution. For vanadate solutions containing 2.0, 5.0, 10, 20 and 25 g/L Cr, under the most suitable vanadium precipitation conditions, the precipitation of vanadium is 83.5%, 80.1%,73.8%, 61.2% and 60.3%, respectively.

Effective Extraction of Vanadium from Bauxite-Type Vanadium Ore Using Roasting and Leaching

A new bauxite-type vanadium ore with a grade of 0.96% V2O5 was found in Hanzhong, China, having quartz, illite, and calcite as the main mineral constituents and vanadium that mainly occurs in the aluminosilicate lattice of illite by replacing Al3+ with V3+ in isomorphism form. In this study, a novel process of low-temperature sulfating roasting–water leaching is presented to extract vanadium from the bauxite-type vanadium ore. Addition of sulfuric acid enhanced the conversion of vanadium to NaVO3 in the sulfating roasting process, and addition of ammonium molybdate improved the leaching efficiency in water leaching. The results showed that a leaching efficiency of 90.33% was obtained under optimal test conditions. The calculation results of standard Gibbs free energy (ΔrGθ) further verified that the formation of NaVO3 is feasible.

Efficient Vanadium Extraction from Shale with High Silicon Content Using a Short Flow Process by Roasting-Water Leaching: Laboratory and Industrial Scale Research

Efficient Vanadium Extraction from Shale with High Silicon Content Using a Short Flow Process by Roasting-Water Leaching: Laboratory and Industrial Scale Research

Extraction of the Rare Element Vanadium from Vanadium-Containing Materials by Chlorination Method: A Critical Review

Vanadium as a rare element has a wide range of applications in iron and steel production, vanadium flow batteries, catalysts, etc. In 2018, the world’s total vanadium output calculated in the form of metal vanadium was 91,844 t. The raw materials for the production of vanadium products mainly include vanadium-titanium magnetite, vanadium slag, stone coal, petroleum coke, fly ash, and spent catalysts, etc. Chlorinated metallurgy has a wide range of applications in the treatment of ore, slag, solid wastes, etc. Chlorinating agent plays an important role in chlorination metallurgy, which is divided into solid (NaCl, KCl, CaCl2, AlCl3, FeCl2, FeCl3, MgCl2, NH4Cl, NaClO, and NaClO3) and gas (Cl2, HCl, and CCl4). The chlorination of vanadium oxides (V2O3 and V2O5) by different chlorinating agents was investigated from the thermodynamics. Meanwhile, this paper summarizes the research progress of chlorination in the treatment of vanadium-containing materials. This paper has important reference significance for further adopting the chlorination method to treat vanadium-containing raw materials.

Synergetic strengthening mechanism of ultrasound combined with calcium fluoride towards vanadium extraction from low-grade vanadium-bearing shale

The effect and mechanism of ultrasound and CaF2 on vanadium leaching from vanadium-bearing shale were investigated systematically. In consideration of the enhancement for vanadium recovery, the combination of ultrasound and CaF2 (66.28%) exerts more evident effects than ultrasound (26.97%) and CaF2 (60.35%) alone, demonstrating the synergetic effect of ultrasound and CaF2. Kinetic analysis manifests that the product layer diffusion controls vanadium leaching in ultrasound system without CaF2, however product layer diffusion and interfacial reaction is the rate-controlling step for vanadium leaching in other three leaching systems. The combination of ultrasound and CaF2 notably decreases the activation energy (Ea) from 62.03 to 27.61 kJ/mol, nevertheless individual CaF2 only reduces the Ea to 50.70 kJ/mol. X-ray diffraction and fourier transform infrared spectrometer analyses show that the decomposition degree of the vanadium-bearing mica structure is the most significant in ultrasound and CaF2 system, proving the highest release degree of vanadium. Specific surface area and pore distribution combined with scanning electron microscope analyses reveal that the action of ultrasound and CaF2 would provide higher specific surface area, more abundant pores structure and cracks for the particles, which further prompts the rapid diffusion of H+, F− and HF, and achieves the conspicuous improvement of vanadium leaching recovery.

Citric acid mediated leaching kinetics study and comprehensive investigation on extraction of vanadium (V) from the spent catalyst

The extraction and leaching kinetics of V from the spent catalyst (3.06 %V, 10.01% Fe and 0.52 % Mg) was investigated using organic citric acid. The characterization of the spent catalyst sample by XRD, EDAX and SEM was examined to ascertain the existence of V, Mg and Fe in the form of respective oxides. Different organic acids were tested to ensure the leaching performance towards extraction of V, Fe and Mg and based upon the efficacy, the metal extrication trend followed the order as; Citric acid > Tartaric acid > Acetic acid > Formic acid > Oxalic acid. The critical parameters such as citric acid concentration, agitation speed, temperature, S/L and particle size, affecting on either of the metal leaching was systematically examined at varying time extent to establish the leaching mechanism as well as for attaining suitable optimum condition for effective dissolution of vanadium. The leaching kinetics of V, Mg and Fe was governed by diffusion controlled mode while following to shrinking core model mechanism as evident from the correlation coefficient (R2 = 0.99) and the resultant activation energy (11.21 kJ/mole for V, 10.86 kJ/mole for Mg and 11.84 kJ/mole, for Fe). The dissolution behaviour of either of metals examined at various particle size ranges as well as citric acid concentrations follows the linearity trend with above proposed leaching kinetics model. More than 99% of Vanadium, 80% Fe and 75 % Mg leaching was resulted at the optimum condition: S/l: 4%, Citric acid: 1.0 M, temp: 373 K, Particle size: 46-75micron. The residue obtained after leaching at the above optimum condition was further analyzed by XRD and EDAX, indicating no peak due to Vanadium and confirms on almost all extraction of V from the spent catalyst phase.

Separation and recovery of V, Ti, Fe and Ca from acidic wastewater and vanadium-bearing steel slag based on a collaborative utilization process

Two typical wastes (acidic wastewater and vanadium-bearing steel slag) produced in the metallurgical process of vanadium-titanium magnetite not only pose a huge threat to the environment, but also waste a lot of resources such as V, Ti, and Fe. In order to effectively treat the two wastes and recover the resources such as V, Ti, Fe and Ca, a collaborative utilization process has been studied. When the O/A ratio of 1.5, the P204 concentration of 20% (v/v), the single-stage extraction rate of titanium was above 96%. After two-stage countercurrent extraction, the extraction rate of Ti can be reached 99.86%, while the co-extraction rate of Fe was less than 3%. The leaching rates of V, Fe, and Mg in the vanadium-bearing steel slag were respectively 98.68%, 99.67% and 99.63% under the condition of a ratio of the volume of the raffinate after titanium extraction to the mass of the vanadium-bearing steel slag at 8:1 (75 min at 60 °C). The analysis through XRD proves that the leaching conditions had an effect on the composition of the leaching slag, of which temperature had the greatest impact on it, and the composition of the leaching slag was anhydrite at 90 °C. After the leaching solution was pre-reduced with ammonium sulfite, the P507 extractant can separate V and Fe very well, and the V-loaded organic phase was treated by ammonium carbonate stripping and calcination process, the product of V2O5 with a purity of 99.03% can be obtained. Additionally, after the raffinate after vanadium extraction was oxidized with H2O2 solution and neutralized with ammonia solution, the solid product and solution obtained by filtration were respectively processed to obtain a roasted slag containing 72.14% Fe2O3 and a product of 99.09% purity of (NH4)2SO4.

A near-zero-waste approach using simple physical-chemical methods recovery high concentrations of ammonia nitrogen, heavy metal, and sodium salts from hazardous vanadium-extracted solution

An integrated simple physical-chemical method was proposed to realize the comprehensive utilization of valuable resources from vanadium-extracted solution. The hazardous vanadium-extracted solution contains high concentrations of Cr(VI), ammonia nitrogen, sodium salt, and silicic acid. Firstly, a series of operations include reduction-precipitation, calcination, and leaching were used to recover high concentration Cr(VI), and 99.96% of Cr(VI) was recovered as chromium oxide with the purity of 97.24%. Optimum conditions for the reduction pH, amount of sodium sulfite, precipitation pH, and precipitation time were 2.0, 1.2 times theoretical, 7.3, and 15 min, respectively. Secondly, clean ammonia nitrogen recovery through waste heat distillation was realized. And the total recovery efficiency of ammonia nitrogen was 95.6% at pH = 11.0, distillation 50 min with 0.5M sulfuric acid as the absorption liquid. Also, the distillation residue sodium sulfate was concentrated and purified by distillation. Finally, all the resources were separated efficiently and could be reused back into the upstream vanadium extraction process, achieving resource recycling. Moreover, material balance, energy analysis and the flow chart of the near-zero-waste approach for resource recycling from the hazardous vanadium-extracted solution were concluded.

Mechanism of vanadium selective separation from iron in shale under an environmentally friendly oxalate ligand system

Iron impurity ion is easy to precipitate or co-extracted together with vanadium in the process of vanadium extraction from shale, reducing vanadium product purity. In our previous research, the technological parameters of vanadium separation over iron from shale using oxalic acid were systematically investigated. In this paper, the reaction mechanism of vanadium selective separation from iron in leaching-precipitation process was detailed studied. In the C2O42-/F- multiple ligands leaching system, the thermochemistry and solution chemistry calculations indicate that vanadium in KAl3Si3O10(OH)2 reacted with H2C2O4/HC2O4-/C2O42-, and then generated VOC2O4 and VO(C2O4)22–. The Fe2O3 reacted with H2C2O4/HC2O4-/C2O42- and HF/F-, and then generated FeF3, Fe(C2O4)2- and Fe(C2O4)33–. Meanwhile, the FeF3 was dissolved as Fe(C2O4)2- and Fe(C2O4)33– in oxalic acid. As a result, the Fe impurity in the leachate mainly existed as Fe(C2O4)2- and Fe(C2O4)33–. In precipitation process, the Fe reductant combined with Fe(C2O4)2- and Fe(C2O4)33–, reducing Fe(III) to Fe(II). Finally, the FeC2O4·2H2O product with a high purity of 98.5% and a mean particle size of 5.41 μm can be obtained at 25℃. The revealed reaction mechanism can strengthen theoretical foundation of selective and clean vanadium extraction from shale.

Separation and recovery vanadium (V) and chromium (Ⅵ) using amide extractants based on the steric hindrance effect

As all existed in the form of anion, the separation of vanadium (V) and chromium (Ⅵ) in weak acid solution was a difficult issue. The study developed an efficient way to achieve the separation of V(V) and Cr(Ⅵ) based on the steric hindrance effect of amide extractants. The effects of different parameters on extraction were studied to explore the optimum conditions. The recoveries of vanadium and chromium were above 97.0% and 99.8%, respectively. The extraction of vanadium with amide was an exothermic reaction. The purity of V2O5 obtained was 99.97%. The V(V) complex of amide was confirmed to be R2H6V10O28. The extraction mechanism was studied with ESI-MS and FT-IR in depth. The extraction of V(V) with amide followed ion association with hydrogen bonding. A promising way was provided to separate vanadium (V) and chromium (Ⅵ) in leaching solution with amide under weak acid condition.

Application of response surface methodology for roasting optimization in composite roasting—Acid leaching vanadium extraction process

Composite roasting with CaO/MgO and leaching process is an environmentally friendly and simple technique in the treatment of vanadium slag which has been practiced using CaO and MgO as composite roasting additives. The recovery of vanadium is significantly influenced by the roasting parameters, viz., CaO/V2O5 mole ratio (x1), MgO/V2O5 mole ratio (x2), roasting temperature (x3), and holding time (x4). Therefore, the response surface method (RSM) and central composite design (CCD) were performed to model and optimize the roasting factors in this research. The results shown that the models for the dissolution of vanadium, phosphorus, and manganese show good concordance with the experimental data. Additionally, a multiple response simultaneous optimization using the desirability function was used to find the optimum roasting conditions for the leaching efficiency of vanadium, phosphorus, and manganese. The optimal results were obtained at x1 = 0.84, x2 = 0.40, x3 = 900 °C, and x4 = 1.89 h. Under these conditions, 90.87% vanadium, 13.64% phosphorus, and 48.61% manganese were leached, which were beneficial not only to the recovery of vanadium but also to the minimization of impurity element of phosphorus and the maximum recovery of manganese.

Thiol modified bimodal mesoporous silica nanoparticles for removal and determination toxic vanadium from air and human biological samples in petrochemical workers

Investigation of exposure to toxic vanadium (V) in petrochemical workers is very important for human health, and it must be removed and determined in workplace air and human biological samples. In this research, the enriched adsorbent based on the thiol modified bimodal mesoporous silica nanoparticle (HS-UVM7) was used for the extraction vanadium in human blood by the dispersive sonication ionic liquid micro solid phase extraction (DS-IL-μ-SPE) at pH of 4.5. In addition, the vanadium (V) was removed from the industrial workplace air based on HS-UVM7 adsorbent by the liquid-solid phase-gas removal (LSP-GR). In the static and dynamic system, the vanadium (V) was removed from artificial air with HS-UVM7 and compared with the polyvinyl chloride membrane (PCM, sorbent in 7300 NIOSH). The LSP-GR procedure based on HS-UVM7 had more recovery and adsorption capacity as compared to PCM. The adsorption capacity of HS-UVM7 and UVM7 adsorbents were obtained 144.1 mg g−1 and 23.3 mg g−1, respectively. In addition, the main parameters effected on extraction vanadium in blood samples and removal from air were studied and optimized by ET-AAS. The LOD, RSD%, linear range (LR) and enrichment factor (EF) was achieved 0.03 μg L−1, 3.1, 0.1–4.5 μg L−1 and 48.7, respectively for extraction of vanadium in 10 mL of blood samples by the DS-IL-MSPE procedure. The validation of the methodology was confirmed by standard addition to gas phase and using certified reference materials (CRM, NIST) or ICP-MS in human blood samples.

Experimental design modelling for the extraction of vanadium(IV) extraction V(IV)-SO<sub>4</sub> <sup>2-</sup> (H+, Na+)-Cyanex 301-kerosene system

The vanadium(IV) extraction from acidic sulphate medium by Cyanex 301 (bis-(2,4,4-trimethylpentyl) dithiophosphinic acid) dissolved in kerosene is explored from the modelling point of view. The time of equilibration is only 10 min and above pH(eq) = 2, high extraction (>90%) occurs.On keeping organic to aqueous phase ratio of 1, factors affecting the extent of extraction (log D and log CD) are pH(eq), [V(IV)],[SO4 2-], [Cyanex 301]and temperature (T). The high (+) and low (-) levels are considered for the factors. The 25 factorial design is used to find the regression equation for the V(IV) extraction by Cyanex 301. On symbolizing pH(eq), log [V(IV)], , log [SO4 2-], log [Cyanex 301], and 1/T (K-1); where concentration terms are in mol/L, as P , M, S,E, and (1/T), respectively,the regression equation obtained is: log CD = 1.95 - 0.23 M + 1.83 P + 2.07 E + 0.84 S - (888.9/T) - 0.26 PS.The current system shows only the interaction effect among pH(eq) and [SO4 2-]. The equation can well describe the system,and it can be used to optimize factors for satisfactory extraction.
 Bangladesh J. Sci. Ind. Res.56(2), 95-104, 2021

Enhancing the Vanadium Extraction Performance Using Synergistic Mixtures of D2EHPA and TBP in RDC Column with the Perforated Structure; Case Study: Evaluation Probability Density Functions

The reactive extraction behavior on the mean drop size and distribution for synergistic extraction of vanadium from sulfate medium with di-(2-ethylhexyl) phosphoric acid (D2EHPA) and its mixture with tributyl phosphate (TBP) in kerosene has been interpreted in the modified rotating disc contactor column. In batch experiments, the maximum extraction efficiency was obtained in the single extraction system with 0.29 molar D2EHPA at an equilibrium pH of 2, whereas the extraction percentage was significantly increased by adding 0.3 molar TBP into the same D2EHPA concentration due to the synergistic effect. The solvent extraction process has been optimized by applying the central composition design approach in the column experiments. The influence of operational variables such as agitation rate and both phase flow rates as well as the type of used systems have been investigated on drop behavior. A unified model was provided for modified rotating disc columns. It was found from Monte Carlo simulation for uncertainty analysis that the agitation speed and type of utilized systems, namely reactive or physical systems have more profound impacts on the mean drop size. The optimum conditions were obtained at the agitation rate of 400 rpm, and phase flow rates equal to 26 L/h.

LyondellBasell reports 1Q 2021 earnings: Technology

As all existed in the form of anion, the separation of vanadium (V) and chromium (Ⅵ) in weak acid solution was a difficult issue. The study developed an efficient way to achieve the separation of V(V) and Cr(Ⅵ) based on the steric hindrance effect of amide extractants. The effects of different parameters on extraction were studied to explore the optimum conditions. The recoveries of vanadium and chromium were above 97.0% and 99.8%, respectively. The extraction of vanadium with amide was an exothermic reaction. The purity of V2O5 obtained was 99.97%. The V(V) complex of amide was confirmed to be R2H6V10O28. The extraction mechanism was studied with ESI-MS and FT-IR in depth. The extraction of V(V) with amide followed ion association with hydrogen bonding. A promising way was provided to separate vanadium (V) and chromium (Ⅵ) in leaching solution with amide under weak acid condition.

Phase relationship in V2O3-rich region of the V2O3–CaO system between 1573–1773 K at PO2 = 10−10 and 10−11 atm

V2O3–CaO system is one of the fundamental systems in the fields of vanadium extraction and vanadium-containing alloys production. Due to the insufficient experimental study, the data of this system was limited. The present study was carried out between 1300 and 1500 °C (1573–1773 K) at the V2O3-rich region (>56 wt% V2O3), with the controlled partial pressure of oxygen (PO2) at 10-10 and 10–11 atm. High-temperature equilibration experiments, quenching technique and electron probe micro-analyser (EPMA) were adopted to determine the microstructures and compositions of phases at high temperature. The results of phase compositions obtained were used to plot a sub-solidus phase diagram, which showed a great discrepancy with existing publications, and 4 solid-phase regions with their phase boundaries were identified in the present study. The solubility of CaO in V2O3 was found to increase slightly with the temperature under both PO2. The study is expected to fulfil the gaps of thermodynamics information in the V2O3-containing systems.

Optimization of vanadium(V) extraction by 2-ethyl-1-hexanol and the study of extraction reaction mechanism

The aims of the present work are to investigate the mechanism and thermodynamics of pentavalent vanadium (V(V)) extraction by 2-ethyl-1-hexanol and to optimize the extraction process. The stoichiometry of V(V) extraction reaction and the extraction equilibrium constants at different temperatures were determined using the slope analysis method applied to the experimental data. It was shown that the extracted V(V) was in the form of HVO3(ROH) in the organic phase. The standard enthalpy and the standard entropy of extraction reaction were calculated as 39.56 kJ/mol and 54.38 J/(mol.K), respectively. A statistical experimental design method, including Plackett-Burman design (PBD) followed by a central composite design (CCD), was employed to obtain the regression models for the prediction of extraction percentages and to optimize the recovery of V(V) from a synthetic leach solution containing Fe(III), U(VI), Si(IV), and Al(III). The accuracy of the predictive models was proven by the analysis of variance (ANOVA). The optimum condition for selective separation of V(V) was: initial pH of 1.9, extractant concentration of 70 %v/v, and T=59.3 °C. Under the optimum condition, the extraction percentages for V(V), Fe(III), U(VI), Si(IV), and Al(III) were 91.3%, 1.7%, 6.3%, 10.6%, 2.7%, respectively. Developed models were validated by solvent extraction experiments at optimum conditions.

Optimization on Temperature Strategy of BOF Vanadium Extraction to Enhance Vanadium Yield with Minimum Carbon Loss

During the vanadium extraction process in basic oxygen furnace (BOF), unduly high temperature is unfavorable to achieve efficient vanadium yield with minimum carbon loss. A new temperature strategy was developed based on industrial experiments. The new strategy applies the selective oxidation temperature between carbon and vanadium (Tsl) and the equilibrium temperature of vanadium oxidation and reduction (Teq) for the earlier and middle-late smelting, respectively. Industrial experiments showed 56.9 wt% of V was removed together with carbon loss for 5.6 wt% only in the earlier smelting. Additionally, 30 wt% of vanadium was removed together with carbon loss by 13.4 wt% in middle-late smelting. Applicability analyses confirmed Teq as the high-limit temperature, vanadium removal remains low and carbon loss increased sharply when the molten bath temperature exceeded Teq. With the optimized temperature strategy, vanadium removal increased from 69.2 wt% to 92.3 wt% with a promotion by 23 wt%.