Vanadium Resources Research Articles

Glycothermal Synthesis of VO₂(B) Nanoparticles for Gas Sensing Application.

This study represents a facile but efficient glycothermal method for synthesis of vanadium dioxide, VO₂(B) nanoparticles with various geometries from spheres to rods, flakes or their agglomeration structures, by controlling reaction conditions (e.g., vanadium resources, reducing agents and surfactants). The as-prepared VO₂(B) nanoparticles were characterized in microstructure and composition, and also examined in terms of gas sensing performance. It was found that the VO₂(B) nanoparticles exhibit a good sensitivity towards alcohols (ethanol, isopropanol, and butanol) and acetone at the optimised operating temperature of 300 °C. The gas sensing performance was further compared with other vanadium oxides investigated previously, such as V₂O5, Na1.08V₃O8. The plausible gas sensing mechanism of the as-prepared nanoparticles was discussed in detail. This study would expand the family of vanadium oxides that can be made as potential sensors for applications in detecting environmental safety and human health.

Mineral Processing and Metallurgical Treatment of Lead Vanadate Ores

Vanadium has been strongly moving into focus in the last decade. Due to its chemical properties, vanadium is vital for applications in the upcoming renewable energy revolution as well as usage in special alloys. The uprising demand forces the industry to consider the exploration of less attractive sources besides vanadiferous titanomagnetite deposits, such as lead vanadate deposits. Mineral processing and metallurgical treatment of lead vanadate deposits stopped in the 1980s, although the deposits contain a noteworthy amount of the desired resource vanadium. There has been a wide variety of research activities in the first half of the last century, including density sorting and flotation to recover concentrates as well as pyro- and hydrometallurgical treatment to produce vanadium oxide. There have been ecological issues and technical restrictions in the past that made these deposits uninteresting. Meanwhile, regarding the development of mineral processing and metallurgy, there are methods and strategies to reconsider lead vanadates as a highly-potential vanadium resource. This review does not merely provide an overview of lead vanadate sources and the challenges in previous mechanical and metallurgical processing activities, but shows opportunities to ensure vanadium production out of primary sources in the future.

Separation and recovery of iron impurities from a complex oxalic acid solution containing vanadium by K3Fe(C2O4)3·3H2O crystallization

Vanadium and iron have been effectively separated from the acid leachate of vanadium-bearing shale by solvent extraction or ion exchange; however, in these methods, the iron was not recovered, and the comprehensive utilization rates of the resources were low. In this paper, the recovery of iron impurities from a complex oxalic acid solution containing vanadium via the crystallization of K3Fe(C2O4)3·3H2O was investigated. Using the optimum conditions, 90.7% of the Fe was recovered, and only 1.4% of the V and 5.0% of the Al were lost. The concentration of Fe decreased from 5366 mg/L before crystallization to 500 mg/L after crystallization. The crystallized product was then further purified by recrystallization to obtain K3Fe(C2O4)3·3H2O in 99.0% purity, which was characterized using FT-IR, XRD, and SEM. Based on the speciation of vanadium and iron in the oxalic acid system, the mechanism by which the iron impurities were recovered was determined. The mechanism consisted of five main steps: complexation, oxidization, coordination, nucleation, and crystal growth. The recovery of iron impurities from a complex oxalic acid solution containing vanadium via the crystallization of K3Fe(C2O4)3·3H2O is a novel and efficient method, and this process provides a new direction for the comprehensive utilization of vanadium resources.

Separation Processes for Self-Sufficient Recovery of Vanadium Resources in Korea

Vanadium (V) is a transition metal with a silver-gray color. It is commonly used in high-strength alloys because of its ability to improve impact and abrasion resistance, even when only a small amount is added. In recent years, there has been active research into vanadium reduction-oxidation flow batteries (VRFB), which are suitable for use in the development of storage devices for renewable energy applications. Separation and recovery of vanadium from low-grade stone coal ore is currently being investigated in China. Various pre-treatment processes have been studied, such as magnetic separation and gravity separation, that can be used to treat large quantities of ore, as well as flotation processing based on the surface characteristics of the minerals. There is an urgent need for the development of separation technologies to facilitate the self-sufficient extraction of vanadium resources present in Korea.

An Environment-Friendly Process Featuring Calcified Roasting and Precipitation Purification to Prepare Vanadium Pentoxide from the Converter Vanadium Slag

Converter vanadium slag is a byproduct of the iron making process when the vanadium titanomagnetite is used as iron raw material. A cleaner process including calcified roasting, dilute acid leaching, precipitation purification, vanadium precipitation with ammonium salt, followed by thermal decomposition was proposed to extract vanadium resource from this slag. And then vanadium pentoxide with purity over 98% was prepared, which can be used as additives for high strength low alloy steel production. A total vanadium recovery beyond 80% was achieved in this whole process. Since no sodium and potassium salt was introduced, wastewater generated was closed-circulating after removing the enriched impurities of P, Si, Ti and Cr with adding powder CaO. The content of V2O5 in residues after vanadium extraction was lower than 1.2 wt.%, while other valuable metals like Fe, Mn, Cr and Ti were concentrated. With no alkaline metal salts added in this process, the metal resources of Fe, Mn, Cr and Ti in the residues were more feasible to be recovered with pyrometallurgy processes.

Vanadium Redox Flow Batteries Fabricated By 3D Printing and Employing Recycled Vanadium Collected from Ammonia Slag

Vanadium redox flow battery (VRFB) is an energy storage system with separately designable power stacks and reservoir. It is one of the most established systems to convert electrical energy to chemical energy, or vice versa, due to its high reversibility, large storage capacity, and the high stability because of the fact that the redox species remain in solution at all times. Currently, the electrolyte for the VRFB is prepared by the electrolytic reduction of vanadium pentoxide (V2O5) in sulfuric acid to produce a vanadium sulfate solution. However, the cost of the whole system exceeds $200/kWh, while the current cost of vanadium is around $ 23-25 Kg-1, which represents around 30% of the overall capital cost of the battery. In order to reduce the cost of the electrolyte, we provide an environmentally–friendly wet process to extract vanadium from industry ammonia slags near the atmospheric conditions (< 100°C). The ammonia slag was treated in a 1.3 M HNO3 solution in a sealed plastic bottle at 95°C for 48 h. After suction–filtrating the insoluble solid, KClO3 was added to the solution to fully oxidize the vanadium species to V5+. Then the solution pH was raised to 6, at which Ca stays dissolved but the others precipitate, by adding a proper amount of a 15 M NaOH solution to obtain Precipitate A. After filtration and washing, Precipitate A was dried in an oven at 50°C overnight, then dissolved in a 1.8 M H2SO4. After that, the solution pH was adjusted to 14 to achieve Precipitate B, which contains the impurities of Mg, Al, Si, Ti, Ni and Fe. Precipitate B was then filtered out and a clear solution remained, in which V still stays. Finally, the solution pH was adjusted to 3 with sulfuric acid and a Precipitate C was formed in the solution after keeping it at 95°C for 12 h. Precipitate C shows a high content of V with a small amount of Na and S observed from EDS, and XRD of this sample indicated presence of NaV6O15 and Na1.2V3O8 as the main components. All of these treatments are done at low temperature (< 100°C) and successfully condensed V from the ammonia slag. Precipitate C and commercial V2O5 (Aldrich) were dissolved to 2 M sulfuric acid to achieve clear yellow solutions of V5+. The vanadium concentration was adjusted to approximately 0.04 M by measuring UV-vis absorption spectra and concentrated to 0.4 M by distillation. A conventional H-cell separated by a Nafion® membrane was used, while two carbon plates served as positive and negative electrodes for the static battery tests. Charging (formation of V5+ and V2+ states) and discharging (V4+ and V3+ states) cycles were nicely achieved with no notable differences between the samples prepared from Precipitate C and reference V2O5 to prove the usefulness of the vanadium resource collected from the ammonia slag for the VFRB application. In this study, we also demonstrated flow battery system, which is designed by CAD and fabricated by a 3D printer. This technique is so powerful that allows us to quickly test different designed parts in order to study optimum cell design using it as the method of device fabrication. Furthermore, our interests are not limited in printing different parts of the cell body, to develop conductive printable materials for micro structured electrode is also very important to maximize the mass transport for the redox media. We have tried to form composites of conductive materials and plastics for that use, and among those carbon fiber-PDMS (Polydimethylsiloxane) composite shows its potential to be the electrode material for RFB. Different flow channels are designed and 3D structured using this composite, which are also tested in the RFB system.

The Bushveld Complex -Host to the World’s Largest Platinum, Chromium and Vanadium Resources

The geological setting of the Bushveld Complex, the world's largest layered igneous body containing most of the planet's chromium, Platinum Group Elements (PGEs) and vanadium resources, is outlined. The complex is situated in a central position on the ancient Kaapvaal Craton of South Africa, with the mineralisation contained in three large arcuate mafic to ultramafic Limbs, comprised of rocks of the Rustenburg Layered Suite (RLS). The Limbs are overlain by co-magmatic felsic rocks while the floor consists mainly of sediments of the Transvaal Supergroup. The RLS is divided into the Marginal, Lower, Critical, Main and Upper Zones with the chromium and PGE enriched layers occurring in the Critical Zone and the vanadium mineralisation occurring within titaniferous magnetitite layers of the Upper Zone. The chromitite layers are classed into Lower, Middle and Upper Groups and show a general decrease in chromium content upwards from >46% Cr 2 O 3 at the base to 1.5:1 at the base to 5 ppm in the uppermost and economically important PGE bearing chromitite layer (the UG2). The economically important Merensky Reef occurs above the UG2 near the top of the Critical Zone. It typically comprises top and bottom chromitite stringers, separated by up to 14 metres of pyroxenite and/ or pegmatoidal pyroxenite, with the best mineralisation generally being associated with the top chromitite stringer and where the two chromitite stringers are in close proximity to each other. These stringers can eventually merge towards pothole structures in places, with the top stringer transgressing downward to form a range of pothole Reef features. The nature and origin of the Merensky Reef in the Eastern and Western Limbs of the Bushveld Complex is discussed. A synthesis and interpretation of a large amount of platinum mine data from the Western Limb, highlights the great variability in the nature of the Merensky Reef in this segment. Evidence suggests that the top chromitite layer represents a magmatic unconformity resulting from thermo-chemical erosion, reconstitution and mineralisation of the immediate footwall layers that it transgressed. The Platreef, a thick, generally feldspathic pyroxenitic and harzburgitic assemblage, occurs on the eastern flank of the Northern Limb and is broadly equated with the Merensky Reef. About 21 magnetitite layers ranging from massive titaniferous magnetitite, to disseminated and weakly disseminated magnetitite occur within, or are associated with, magnetite gabbro, gabbro and diorite of the Upper Zone. The vanadium content in magnetite is highest in the lowermost magnetitite layers (over 2.2% V 2 O 5 in places) dropping to 1.6% V 2 O 5 in the overlying Main Magnetitite Layer. An important layer (Layer 21 or the Q Layer), towards the top of the Upper Zone, is enriched in titanium (±13% TiO 2 ), at the same time having vanadium values of generally less than 0.2% V 2 O 5 . This layer, which is often over 40 metres thick, contains a huge resource of iron and titanium, as well as vanadium. The mineral apatite appears abruptly at two levels towards the top of the complex, the uppermost occurrence being in a diorite immediately above layer 21 where P 2 O 5 values average 4% over several tens of meters. The use of geophysical and geochemical techniques in exploration and mining in the Bushveld Complex is briefly reviewed and their applicability and effectiveness is illustrated. Given the continuity of layers, including some which extend for well over a hundred kilometres, the resource still present in this unique Complex is vast.

Main types of rare-metal mineralization in Karelia

Rare-metal mineralization in Karelia is represented by V, Be, U deposits and In, Re, Nb, Ta, Li, Ce, La, and Y occurrences, which are combined into 17 types of magmatic, pegmatite, albitite–greisen, hydrothermal–metasomatic, sedimentary, and epigenetic groups. The main vanadium resources are localized in the Onega ore district. These are deposits of the Padma group (556 kt) and the Pudozhgorsky complex (1.5 Mt). The REE occurrences are primarily characterized by Ce–La specialization. The perspective of HREE is related to the Eletozero–Tiksheozero alkaline and Salmi anorthosite–rapakivi granite complexes. Rare-metal pegmatites bear complex mineralization with insignificant low-grade resources. The Lobash and Jalonvaara porphyry Cu–Mo deposits are potential sources of rhenium: Re contents in molybdenite are 20–70 and 50–246 ppm and hypothetical resources are 12 and 7.5 t, respectively. The high-grade (∼100 ppm) and metallogenic potential of indium (∼2400 t) make the deposits of the Pitkaranta ore district leading in the category of Russian ore objects most prospective for indium. Despite the diverse rare-metal mineralization known in Karelia, the current state of this kind of mineral commodities at the world market leaves real metallogenic perspective only for V, U, Re, In, and Nb.

Fe-Ti-V-(P) resources in the Upper Zone of the Bushveld Complex, South Africa

The Bushveld Complex in South Africa is the largest layered intrusion on Earth. Its upper part is known for huge resources of iron, titanium, vanadium and phosphorus. Associated with the layered character of the rocks, these resources are enriched at certain levels of the intrusion, which makes it important to understand the formation processes of those layers. In this paper we give an introduction and overview of recent debates and challenges.

Vanadium-bearing magnetite in the Kohyama gabbro, Hagi, Yamaguchi prefecture, Japan. Especially for vanadium resource potential

Vanadium-bearing magnetite in the Kohyama gabbro, Hagi, Yamaguchi prefecture, Japan. Especially for vanadium resource potential

Vanadium resources and their metallogenesis

Vanadium resources and their metallogenesis

Simulation and Application of Swirl‐Type Oxygen Lance in Vanadium Extraction Converter

AbstractStirring effects and impacting characteristics of conventional and various swirl‐type oxygen lances (Swirl angles are 5°, 10°, and 13°, respectively) on the molten pool were studied. The mixing time, impacting depth and impacting diameter were measured by water model experiment. The flow field characteristics of gas–liquid two phase flow were simulated using Fluent software. It is found that 10° swirl‐type oxygen lance injection can get the shortest mixing time which is only 47.6 s. The area surrounded by isovelocity is larger in molten pool when injecting by the swirl‐type oxygen lance. When injecting by the 10° swirl‐type oxygen lance, the area is the largest and the flow velocity of liquid steel is the highest. On this basis, the 10° swirl‐type oxygen lance was experimented in 150 t vanadium extraction converter. The experiment shows that the swirl‐type oxygen lance can guarantee the normal smelting process. Compared with the conventional oxygen lance, the reduction ratio of vanadium content in semi‐steel is 17.8%, vanadium extraction rate is increased by 5.1%, V2O5 grade of vanadium slag is increased by 0.93% and iron loss is reduced. It provides a new technology to improve the recovery of vanadium resources in converter.

Effect of Vanadium-Nitrogen Concentration and Cooling Rate on Grain Refinement in V-N Steel

Effect of vanadium and nitrogen concentration in V-N steel and cooling rate after deformation on grain refinement has studied in this paper. The results show that with the increase of vanadium and nitrogen concentration, ferrite grain size is smaller compared with carbon steel; with the increase of cooling rate after deformation, ferrite grain size is finer and pearlite content of microstructure significantly is reduced too. Compared with the Nb-bearing steel, as long as selecting reasonable the process parameters and adding the appropriate vanadium, nitrogen to the steel, V-N steel can also get a good strength and toughness, and the cost is lower than Nb-bearing steel. This method of producing the steel with good Strength and toughness is very suitable to China who possesses the abundant vanadium resource, but is lack of niobium.

Mineral and energy policies*

Recent years have seen significant growth in the mineral and energy resource industries globally. In Australia, the mining boom has impacted on the broader economy through appreciation of the Australian dollar resulting from strong resource exports. At the same time, the Australian Government is moving to introduce a mining tax and a price on carbon, both of which will have significant impacts on the resources sector. The environmental and social impacts of mining continue to be an important focus of public debate and academic research. With such momentous changes underway, a special issue of AJARE focusing on these themes is well-timed. Australia is well endowed with a range of mineral and energy resources. Australia has the largest economic demonstrated resources of brown coal, lead, rutile, zircon, nickel, silver, uranium and zinc, as well as significant resources of antimony, bauxite, black coal, copper, gold, industrial diamond, iron ore, ilmenite, lithium, manganese ore, niobium, tantalum, tungsten and vanadium. The resources sector is an important contributor to the Australian economy. In 2010–2011 in industry gross value-added terms, mineral resources accounted for around nine per cent of GDP ($117.7 billion). In 2010–2011, resources and energy sectors exports were valued at $177.4 billion and accounted for a record 83.9 per cent of commodity exports and 59.5 per cent of total goods and services exports. In employment terms, the resources sector is a small part of the Australian economy, accounting for less than two per cent of total employment in 2010–2011. Despite this small number, the relatively high wages paid by this sector present a challenge for other industries competing for labour.

Research on Preparation and Performance of Vandium Tailings-based Geopolymer

ABSTRACTVanadium-beard bone coal is one of important vanadium resources in China. to extract vanadium tailings from Stone coal is prduced after extracted vanadium from stone coal through the roasting, leaching and other processes. About 120-150 tons of tailings will be produced in extracting 1 ton of vanadium pentoxide. A lot of tailings that are willfully piled up have caused serious environmental pollution and wasting of resources; it is therefore necessary to realize its resource utilization. This study increases the activity of vanadium tailings by means of alkali fusion, and then uses different alkali activators to react with vanadium tailings so that geopolymer with high value added is produced. Sample of geopolymer is acquired from mixture containing vanadium tailings, alkali activators, water and a little sodium aluminate through compression-molding process under 20MPa pressure. After cured in room temperature for three days, the maximum compressive strength of the sample can reach 36.2MPa. XRD analysis indicates: quartz, the major crystal phase in vanadium tailings is decomposed and the activity of vanadium tailings is heightened. FTIR and SEM analyses show: structural change having important impact on the mechanical strength of geopolymer occurred during the process of vanadium tailings generating geopolymer.

Synthesis and electrochemical properties of single-crystalline LiV 3O 8 nanobelts for rechargeable lithium batteries

Single-crystalline LiV 3O 8 nanobelts have been synthesized by using V 2O 5 nanobelts as the vanadium resource via a facile solid-state reaction method. The LiV 3O 8 nanobelts with thickness of less than 20 nm, widths of 100–300 nm, and length up to several micrometers can grow along the [ 2 ¯ 01] direction. The small thickness of LiV 3O 8 nanobelts are expected to shorten the Li + ion diffusion distance for the improved electrochemical performance of electrode material. The influence of types of lithium salts on the morphologies and sizes of LiV 3O 8 nanostructures has been investigated. When used as the cathode material in rechargeable lithium batteries, LiV 3O 8 nanobelts exhibit stable lithium-ion intercalation/deintercalation reversibility and deliver initial specific discharge capacities of around 356.2 mAh/g at 0.02 A/g, 273.6 mAh/g at 0.05 A/g, and 234.0 mAh/g at 0.1 A/g, respectively. After 30 cycles, the specific discharge capacities are lowered to 298.6 mAh/g at 0.02 A/g, 234.5 mAh/g at 0.05 A/g, and 195.5 mAh/g at 0.1 A/g, respectively. The good electrochemical properties of LiV 3O 8 nanobelts make them a promising candidate as a cathode material for rechargeable lithium batteries.

Vanadium resource of the iron sand deposits in Japan

Vanadium resource of the iron sand deposits in Japan

Synthesis and electrochemical properties of single-crystalline LiV3O8 nanorods as cathode materials for rechargeable lithium batteries

One-dimensional (1D) nanorods of LiV 3 O 8 single crystals have been fabricated by using well-defined home-made VO 2 (B) nanorods as the vanadium resource, combined with a convenient solid-state reaction. The as-obtained LiV 3 O 8 nanorods were characterized by XRD, TEM and SEM, indicating this material was highly crystalline and a single phase. The electrochemical performance of LiV 3 O 8 nanorods as the positive electrode material for rechargeable lithium batteries was investigated, which demonstrated that as-prepared LiV 3 O 8 nanorods exhibited as high as 348 mAh g −1 discharge capacity in first cycle at 20 mA g −1 current density, and still remained at 303 mAh g −1 at 50 mA g −1 afterwards; moreover, until 50 cycles, they kept 315 mAh g −1 , recorded at 50 mA g −1 . All these results imply that single-crystalline 1D nanorods of LiV 3 O 8 are promising cathode material for rechargeable lithium batteries.

PRECISE AGE OF THE PLATINIFEROUS MERENSKY REEF, BUSHVELD COMPLEX, SOUTH AFRICA, BY THE U-Pb ZIRCON CHEMICAL ABRASION ID-TIMS TECHNIQUE

The Bushveld Complex, South Africa, is the world’s largest layered intrusion and host to the majority of the known resources of platinum group elements, chromium, and vanadium. Despite intensive study, determining the precise crystallization age of the Bushveld Complex has proven to be difficult. In this study, zircon and rutile were identified in thin section and separated from a sample of pegmatitic feldspathic orthopyroxenite from the PGE-rich Merensky reef, West mine (Townlands shaft), Rustenburg section. Low U (21–105 ppm) zircon occurs with interstitial biotite and is locally in direct contact with sulfide. Rutile occurs mainly as inclusions within or overgrowths on chromite, especially in the chromitite stringers that bound the reef, and also as acicular grains with biotite. A U-Pb crystallization age of 2054.4 ± 1.3 Ma was determined from single-crystal chemical abrasion ID-TIMS U-Pb dating of zircon, and multigrain fractions of rutile yielded a U-Pb cooling age of 2055.0 ± 3.9 Ma. Integration of the Merensky reef crystallization age with existing U-Pb age determinations for intrusions that pre- and postdate emplacement and crystallization of the layered rocks of the Bushveld Complex indicate that magmatism occurred at ca. 2054 Ma and is contemporaneous with related magmatic activity across the northern Kaapvaal craton of South Africa and Botswana.

The age and petrology of the Chimbadzi Hill Intrusion, NW Zimbabwe: first evidence for early Paleoproterozoic magmatism in Zimbabwe

The mafic-ultramafic Chimbadzi Hill intrusion in the NW of the Zimbabwe craton is a dyke with inward-dipping margins comprising magnetite peridotite, troctolite and magnetite melatroctolite. The magnetite peridotite is composed of about equal amounts of V- and Ti-bearing magnetite and olivine (∼Fo 60). The troctolite is composed of about 50% olivine (∼Fo 50-54), 40% plagioclase (An 53-58), 7% clinopyroxene and minor apatite and magnetite with ilmenite lamellae. Geochemical trends suggest that the Chimbadzi Hill Intrusion formed by fractional crystallisation from a single initial magma. However, the more primitive magnetite peridotite overlies the more evolved troctolite in the intrusion. This ‘apparent’ inverted stratigraphy may be due to emptying of a fractionated magma chamber from the top, or to floor subsidence during intrusion. U–Pb dating on baddeleyite reveals that the age of the Chimbadzi Hill Intrusion is 2262 ± 2 Ma. This age does not correspond to any known tectono-thermal event in the Zimbabwe Craton or adjacent metamorphic belts. It is ∼300 Ma younger than the late Archean Great Dyke, and ∼230 Ma older than other Paleoproterozoic events in and around the craton. Therefore, it may represent a so far undocumented very early Proterozoic igneous event in the Zimbabwe Craton. The intrusion represents a vanadium resource for Zimbabwe, with titanium potentially being mined as by-product.