Vanadium Titanium Research Articles

Configuration Effect of Plasmonic Vanadium–Titanium Solid Solutions for Photo-oxidation of Benzyl Alcohol

Configuration Effect of Plasmonic Vanadium–Titanium Solid Solutions for Photo-oxidation of Benzyl Alcohol

Enrichment and reconfiguration of titanium-bearing phase in vortex smelting reduction process of vanadium–titanium magnetite

Enrichment and reconfiguration of titanium-bearing phase in vortex smelting reduction process of vanadium–titanium magnetite

Influence of composition and temperature on distribution behavior of V, Ti and Si in HIsmelt

The effect of temperature and composition on the distribution behavior of V, Ti and Si in HIsmelt smelting vanadium–titanium magnetite was investigated, and the feasibility of HIsmelt smelting vanadium–titanium magnetite with natural basicity was evaluated. The thermodynamic calculations showed that higher FeO content and basicity, and lower C content and temperature are favorable for improving vanadium and titanium distribution ratio. However, reducing basicity and FeO content benefits the recovery of vanadium and titanium resources in hot metal and slag. It is proposed that in the HIsmelt smelting vanadium and titanium magnetite, the basicity is kept between 1.1 and 1.2, and the temperature is in the range of 1400–1450 °C. The experimental results indicate that there are difficulties in HIsmelt smelting vanadium–titanium magnetite with natural basicity.

Reduction of chengde vanadium titanium magnetite concentrate by microwave enhanced Ar–H2 atmosphere

In this study, a new method of microwave-enhanced hydrogen reduction was developed to carry out isothermal reduction experiments. The effects and mechanisms of different hydrogen volume fractions on the direct reduction behavior of a vanadium titanium magnetite concentrate (VTM) were investigated. The experimental results and theoretical analysis proved that combining the advantages of microwaves and hydrogen to reduce the VTM is feasible. The thermodynamics of the non-microwave field indicated that the hydrogen reduction of iron titanium oxides was more difficult than that of iron oxides and required a higher reaction temperature. Under microwave heating conditions, with an increase in hydrogen volume fraction, the metallization rate and reduction degree increased, the microscopic morphology developed into a porous sponge-like structure, the size of the internal pores increased, and the migration of metallic iron to the edges of the particles became obvious. When the hydrogen volume fractions exceeded 60%, the products did not contain TiO2, and the final products consisted of metallic iron containing a small amount of dissolved Ti. The reduction reaction was controlled by gas phase diffusion, and the average apparent activation energy was calculated to be 84.05 kJ/mol using a new kinetic model. Moreover, increased hydrogen volume fraction weakened the gas phase diffusion and was converted into internal diffusion.

Softening-melting Properties of High-chromium Vanadium–titanium Magnetite Pellets with Different Basicity

Softening-melting Properties of High-chromium Vanadium–titanium Magnetite Pellets with Different Basicity

Prediction of the Vanadium Content of Molten Iron in a Blast Furnace and the Optimization of Vanadium Extraction

The vanadium content of molten iron is an important economic indicator for a vanadium–titanium magnetite smelting blast furnace, and it is of great importance in blast furnace production to be able to accurately predict it and optimize the operation of vanadium extraction. Based on the historical data of a commercial blast furnace, the clean data were obtained by processing the missing data and outlier data for data mining analysis and model development. A combined wavelet-TCN model was used to predict the vanadium content of molten iron. The average Hurst index after wavelet transform was calculated to reduce the complexity of the wavelet transform layer selection and the model computation time. The results show that compared to single models, such as LSTM, LSTM with attention, and TCN, the combined model based on wavelet-TCN (a = 5) had an improvement of about 11~17% in R2, and the prediction accuracy was high and stable, which met the practical requirements of blast furnace production. The factors affecting the vanadium content of molten iron were analyzed, and the measures to increase the vanadium content were summarized. A blast furnace should avoid increasing the titanium dioxide load, increase the vanadium load appropriately, and keep the relevant operating parameters within the appropriate range in order to achieve the optimization of vanadium extraction from molten iron.

Titanium Impurity Control in V-Bearing Pig Iron Prepared via the Sodium Smelting of Vanadium–Titanium Magnetite

The sodium smelting of vanadium–titanium magnetite (VTM) can realize a multi-component comprehensive utilization of VTM. To broaden the application of the vanadium-bearing pig iron produced through this process, it is imperative to maintain the titanium content in molten iron at a very low level. In this study, the effects of temperature, the added amounts of sodium carbonate and anthracite, and the smelting time on the titanium content of molten iron were investigated using thermodynamic calculations and experiments. The results indicate that the introduction of sodium carbonate makes the reduction reaction of VTM a relatively low-temperature smelting system. In the smelting process, the Ti content in molten iron increases with the increase in temperature and decreases with the addition of sodium carbonate, while the amount of anthracite added has little effect on it. The appropriate technological parameters were determined as temperature: 1150–1250 °C, smelting time: ≥2 h, anthracite consumption: 25–35%, and sodium carbonate consumption: ≥60%. In addition, it was determined that the Ti impurities in the V-bearing pig iron were mainly (Ti,V)(C,N), CaTiO3, and Na2TiO3. All results obtained from this work contribute to the comprehensive utilization of VTM, and also provide theoretical support for the sodium smelting of VTM.

Impact of Deposition Power and Gas Flow Ratio on the Tribological Properties of Titanium Vanadium Nitride Thin Films.

Magnetron sputtering was used for producing titanium vanadium nitride (TiVN) coatings on brass substrates. In this research, we investigate how changing the sputtering power and nitrogen:argon (N2:Ar) gas ratio affects the structural and tribological properties of TiVN coatings. A scanning electron microscope (SEM) was used to examine TiVN coating surface morphology. Both variants showed a gradual increase in the intensity of the TiVN coatings' (111) and (222) peaks. The TiVN coatings' tribological properties were examined using a pin-on-disc tribometer with varying loads, speeds, and sliding distances. The wear rates of TiVN-coated brass pins were in the range of 2.5 × 10-4 to 9.14 × 10-4 mm3/Nm depending on load, sliding distance, and gas ratio variation, when compared to the wear rates of TiVN-coated brass pins deposited at various powers, which ranged from 1.76 × 10-3 to 5.87 × 10-3 mm3/Nm.

Hydrogen adsorption by a porous bimetallic solid solution carbide MAX phases synthesized in an open atmosphere

Multilayer and porosity are significant traits for energy storage materials, especially for hydrogen storage and utilization. However, the material must first undergo subsequent sequential investigation for accurate quantification to be a candidate for hydrogen storage. The mixed metallic MAX phase and their derivatives MXene have the potential to be used for hydrogen storage. In this paper, we describe the formation of low temperature (1100 °C), porous, and high purity (84.92 %) bimetallic solid solution Titanium Vanadium Aluminum Carbide (TiVAlxC) MAX phases in an open atmosphere, where the variation of x, e.g., Al mole content, is critical for obtaining high purity metallic solid solution MAX phases. The BET comparative analysis shows the textural features of the TiVAlxC with change in Al and end phases, i.e., Ti2AlC (Titanium Aluminum Carbide) and (Vanadium Aluminum Carbide) V2AlC. The outcomes are evident that impurity, crystallinity, and crystallite size impact the textural properties of the synthesized MAX phases. Corelative findings on accurate quantification of hydrogen uptake based upon textural properties. The gravimetric hydrogen storage capacity of Ti2AlC, TiVAl1.3C, and V2AlC phases are 0.33, 0.62, and 1.29%wt, respectively. The gravimetric analysis provided valuable insights into the isothermal hydrogen adsorption of TiVAlxC and its end phases, demonstrating these materials' ability to be used for future hydrogen storage.

Reduction Roasting of the Crude Titanomagnetite Concentrate from the Gremyakha–Vyrmes Deposit with the Formation of a Titanium–Vanadium Slag and a Granulated Metal

Reduction Roasting of the Crude Titanomagnetite Concentrate from the Gremyakha–Vyrmes Deposit with the Formation of a Titanium–Vanadium Slag and a Granulated Metal

Optimal Process Parameters for Direct Carbothermal Reduction of Vanadium–Titanium Magnetite in a Rotary Kiln

Direct reduction in rotary kiln plays a crucial role in the reduction and smelting of vanadium–titanium magnetite. The effect of the process parameters on the metallization rate and reaction mechanism during the reduction process in a rotary kiln is investigated. The results indicate that the optimal process parameters for direct reduction of vanadium–titanium magnetite in a rotary kiln are as follows: a reduction temperature of 1150 °C, reduction time of 4 h, carbon ratio 1.2, particle size of vanadium–titanium magnetite as 8–12 mm, and particle size of pulverized coal of <8 mm. During the direct reduction of vanadium–titanium magnetite, favorable conditions such as absence of smelting phenomenon on the surface of the reduction products, high metallization rate, and high quality of direct reduction iron are achieved. Through direct reduction, the transformation process of iron oxide in vanadium–titanium magnetite is Fe3O4 → iron oxide → Fe, and the transformation process of titanium–iron oxide is Fe9TiO15 → Fe2.75Ti0.25O4 → Fe2.5Ti0.5O4 → iron titanate → Fe. In addition, vanadium and ferrochrome oxides undergo reduction to form oxides or carbides.

A novel method for efficient recovery of ilmenite by high gradient magnetic separation coupling with magnetic fluid

Ilmenite is the main raw material for titanium extraction. The vanadium titanium magnetite deposit in Panzhihua has abundant ilmenite resources. A flowsheet combining high gradient magnetic separation (HGMS) and flotation was applied to recover the ilmenite, which had defects of high production cost due to high flotation regent consumption, low ilmenite utilization rate of 20% as ultrafine minerals were directly discharged into tailings, as well as bring a series of environmental problems. In this study, a novel method termed high gradient magnetic separation coupling with magnetic fluid (HGMSCMF) was developed to recovery ilmenite in Panzhihua. Paramagnetic MnCl2 solutions were introduced to eliminate competing capture between ilmenite and titanaugite particles and improve selectivity. Under equivalent TiO2 recovery, TiO2 grade of magnetic products increased significantly with MnCl2 concentration. Pulsating flow could further strengthen the improvement effect of selectivity by magnetic fluids. For the first time, qualified ilmenite concentrate (TiO2 grade > 46%) with TiO2 recovery equal to that in industrial production was obtained only through HGMSCMF (without using flotation) with one roughing and three cleaning processes under the optimal conditions of MnCl2 concentration 40%, applied induction 0.6 T and pulsating frequency 400 r/min. HGMSCMF presents great potential in solving tough problems being faced in processing weakly magnetic minerals. Follow-up studies will focus on recycling and reuse of magnetic fluids for realizing industrial application of HGMSCMF in recovering ilmenite or other refractory weakly magnetic minerals.

Analysing the HIsmelt process for smelting vanadium–titanium magnetite

ABSTRACT In response to the problem of rich vanadium–titanium magnetite (VTM) resources in China contrasting with low blast furnace utilization, a HIsmelt process for smelting VTM is proposed. The influence of the process parameters on smelting reduction is analysed under laboratory conditions by simulating smelting reduction. The results show that extending the reaction time reduces the FeO content in the slag by 15.34 wt-%, increasing the reaction temperature reduces the FeO content in the slag by 26.38 wt-%, and increasing the basicity reduces the FeO content in the slag by 11.26 wt-%. The control temperature for smelting VTM using the HIsmelt process is 1425°C, with a reduction time of 20–30 min, which is conducive to the transfer of vanadium to the molten iron and the enrichment of titanium in the slag. To ensure vanadium and titanium are efficiently utilized, a basicity control of 0.8 is appropriate.

Reducibility Optimization and Reaction Mechanism of High-Chromium Vanadium–Titanium Magnetite Flux Pellets

Reducibility Optimization and Reaction Mechanism of High-Chromium Vanadium–Titanium Magnetite Flux Pellets

Effect of oxygen enrichment on sintering behavior of high proportion vanadium–titanium magnesite concentrates

Effect of oxygen enrichment on sintering behavior of high proportion vanadium–titanium magnesite concentrates

Enhanced pollutant photodegradation over nanoporous titanium-vanadium oxides with improved interfacial interactions

This study addressed the separation problem of colloidal catalytic powder from its solution and pore blockage of traditional metallic oxides by fabricating nanoporous composites of titanium (Ti)-vanadium (V) oxide via magnetron sputtering, electrochemical anodization, and annealing processes. The effect of V-deposited loading on the composite semiconductors was investigated by varying V sputtering power (20–250 W) to correlate their physicochemical properties to the photodegradation performance of methylene blue. The obtained semiconductors revealed circular and elliptical pores (14–23 nm) and formed different metallic and metallic oxide crystalline phases. Within the nanoporous composite layer, V ions substituted Ti4+, leading to Ti3+ formation accompanied by decreased band gap values and higher visible-light absorption. Thus, the band gap of TiO2 was 3.15 eV, while that of Ti-V oxide with the maximum V content (at 250 W) was 2.47 eV. The interfacial separators between clusters in the mentioned composite created traps disrupting the charge carrier movements between crystallites, thereby decreasing the photoactivity. In contrast, the composite prepared with the minimum V content showed approximately 90% degradation efficiency under solar-simulated irradiation resulting from the homogeneous V dispersion and the lower recombination possibility, owing to its p-n heterojunction constituent. The nanoporous photocatalyst layers with their novel synthesis approach and outstanding performance can be applied in other environmental remediation applications.

Dynamics of vanadium and response of inherent bacterial communities in vanadium–titanium magnetite tailings to beneficiation agents, temperature, and illumination

Vanadium-titanium (V–Ti) magnetite tailings contain toxic metals that could potentially pollute the surrounding environment. However, the impact of beneficiation agents, an integral part of mining activities, on the dynamics of V and the microbial community composition in tailings remains unclear. To fill this knowledge gap, we compared the physicochemical properties and microbial community structure of V–Ti magnetite tailings under different environmental conditions, including illumination, temperature, and residual beneficiation agents (salicylhydroxamic acid, sodium isobutyl xanthate, and benzyl arsonic acid) during a 28-day reaction. The results revealed that beneficiation agents exacerbated the acidification of the tailings and the release of V, among which benzyl arsonic acid had the greatest impact. The concentration of soluble V in the leachate of tailings with benzyl arsonic acid was 6.4 times higher than that with deionized water. Moreover, illumination, high temperatures, and beneficiation agents contributed to the reduction of V in V-containing tailings. High-throughput sequencing revealed that Thiobacillus and Limnohabitans adapted to the tailings environment. Proteobacteria was the most diverse phylum, and the relative abundance was 85.0%–99.1%. Desulfovibrio, Thiobacillus, and Limnohabitans survived in the V–Ti magnetite tailings with residual beneficiation agents. These microorganisms could contribute to the development of bioremediation technologies. The main factors affecting the diversity and composition of bacteria in the tailings were Fe, Mn, V, SO42−, total nitrogen, and pH of the tailings. Illumination inhibited microbial community abundance, while the high temperature (39.5 °C) stimulated microbial community abundance. Overall, this study strengthens the understanding of the geochemical cycling of V in tailings influenced by residual beneficiation agents and the application of inherent microbial techniques in the remediation of tailing-affected environments.

Ce-doped perovskite-type catalyst derived from Ti-bearing blast furnace slag for photocatalytic removal of gaseous toluene under visible light

Since the yield of titanium-bearing blast furnace slag (TF) during the smelting of vanadium titanium magnetite is large, it is urgent to find ways to recycle it and implement its value-added utilization. In this study, a perovskite-rich photocatalyst was prepared by acid-washing of TF, and then Ce was doped to modify it for photocatalytic removal of gaseous toluene under the irradiation of visible light. XRD, XRF and XPS analyses demonstrated that the perovskite phase was enriched after the acid-washing, and the content of CaTiO3 in the acid-washed slag (AS) also increased after Ce doping. The combined N2 adsorption-desorption, UVVis DRS, EIS, PL, and ESR analysis results indicated that the photocatalytic performance of the mentioned photocatalyst was related to the Ce dopant content. The AS doped with 20% Ce (20% Ce-AS) had a lower band gap and larger specific surface area than the others catalysts. Under visible light radiation, more active radicals were produced, and the removal efficiency of toluene reached 92.08% for 20% Ce-AS. In addition, the results of the in situ DRIFTS tests indicated that toluene was gradually degraded by the Ce-doped perovskite-type photocatalyst to alcohols and aldehydes and mineralized to H2O and CO2. This study is expected to provide a new approach for the technical development of the value-added utilization of TF coupled with the efficient removal of toluene.

Study on the Properties of Vanadium Pellets Extracted from Vanadium Titanium Magnetite Concentrate by Calcium Roasting and Acid Leaching

In this study, a clean pellet production method of calcium roasting and sulfuric acid leaching of vanadium from vanadium and titanium magnetite concentrates is proposed, which can effectively separate vanadium and iron, and the pellets after acid leaching and vanadium extraction can be used as raw material for iron making after secondary roasting. During the experiment, only 2% Ca(OH)2 was added as the calcifier to make pellets, and vanadium was extracted by acid leaching after calcination. Under the optimum conditions, the vanadium leaching rate was 74.51%, and the iron leaching rate was only 1.05%. After secondary roasting, the compressive strength of the pellets was 2358 N, and the qualification rate was 97%. Additionally, after acid leaching and vanadium extraction, the impurities in the pellet were partially removed, and the iron content of the pellet increased by 6.6%, which is more conducive to subsequent ironmaking. The roasting and acid leaching experiments show that based on the production of iron smelting pellets, the use of pellets can better extract vanadium from the titanium magnetite concentrate, while avoiding the problems of excessive additives to reduce the iron grade of pellets. Or the pursuit of high vanadium extraction rate pellets, which can be seriously damaged and difficult to use later. This process can perform a comprehensive utilization of vanadium titanium magnetite, and has certain guiding significance for industrial production.

Effects of deposition temperature on the wear behavior and material properties of plasma enhanced atomic layer deposition (PEALD) titanium vanadium nitride thin films

This work investigates the effects of deposition temperature on the wear behavior and material properties of recently developed plasma enhanced atomic layer deposited (PEALD) TiVN films. ∼50–100 nm thick TixV1-xN (x ~ 0.5, hereto referred to as TiVN) films were deposited using PEALD on Si substrates with thermal oxide at a range of deposition temperatures (150 °C, 200 °C, 250 °C, 300 °C, 350 °C). Wear testing was performed on each film using a linearly reciprocating tribometer in a controlled humidity environment. Wear rates of the TiVN films varied with deposition temperature, with the 250 °C sample achieving ultralow wear(5.4 × 10−7 mm3/Nm), while the 150 °C sample wore through the film completely in early sliding cycles. Along with their low wear properties, these PEALD TiVN films were found to have low electrical resistivity when deposited above 150 °C. Film density and crystallite size increased with increasing deposition temperature up to 250 °C, where these properties plateaued. High compressive residual stresses were measured, ranging from 2.7 to 7.7 GPa. XRD Bragg peak intensities showed that films with increasing deposition temperatures had higher degrees of crystallinity. XPS indicated that above 150 °C deposition temperatures, impurities in the film were reduced by ∼4x. Higher deposition temperatures allow for increased adatom mobility, which can lead to higher densities and crystallinity, which are typically associated with lower wear rates. At deposition temperatures below 200 °C, precursor reactivity is sluggish and there is insufficient energy for complete surface reactions to occur, leading to film contamination and less dense films. The subtle differences in wear rates above 200 °C deposition temperature indicated that there are competing material properties that can either contribute to or detract from the wear behavior of the film, and a combination of desirable mechanical, physical, structural, and chemical properties are required for ultra-low wear rates to be achieved. The low wear and friction properties and low electrical resistivity of these films combined with the low deposition temperature, conformality, and atomic layer thickness control of PEALD make them potential candidates for applications such as thermally sensitive microelectronics and MEMS/NEMS.