Recovery Of Niobium Research Articles

STUDIES THE CRUCIAL ROLE OF SELECTION OF EXTRACTANT TO EXTRACT NIOBIUM FROM SULFURYL FLUORIDE SOLUTION AND OPTIMIZATION OF EXTRACTION CONDITIONS

The increasing demand for rare refractory metals such as niobium in high-tech industries requires the development of efficient and sustainable methods to extract them from secondary sources, including industrial by-products. This study studied niobium extraction from a fluoride-sulfuric acid solution obtained by leaching a niobium-containing intermediate product. A comprehensive assessment of various organic extractants, including methyl isobutyl ketone, tributyl phosphate, trioctylamine, and Cyanex 923, was performed, focusing on the recoverability of niobium from this solution. Experimental results show that Cyanex 923 is significantly superior to other extractants in efficacy. The extraction of niobium at different concentrations of this extractant in toluene and the ratios of organic and aqueous phases were studied. It is established that an increase in the contact time of the phases does not contribute to additional niobium recovery. Studies show that applying concentrated Cyanex 923 in toluene ensures complete recovery of niobium into the organic phase. The three-stage counter-current extraction shows a slightly higher niobium recovery efficiency than the single-stage process.

Recovery of niobium and titanium from low-grade niobium ores and the evaluation of Fe5Si3 alloy by-product as oxygen evolution reaction electrocatalysts

A low-grade ore containing 4 % niobium and 7 % titanium has been extracted from Bayan Obo tailing, but its potential has not been fully utilized. This study aims to recover the niobium and titanium elements from this low-grade ores in the form of their carbides. The process involves reducing niobium and titanium to (Nb,Ti)C through a carbothermal process. During this process, iron and silicon are also reduced to Fe-Si intermetallic compounds, allowing (Nb,Ti)C to diffuse into them. Subsequently, selective electrochemical oxidation is used to separate (Nb,Ti)C from the Fe-Si intermetallic compounds in an aqueous ferrous sulfate solution. The Fe-Si intermetallic compounds are first oxidized to the Fe3Si phase, and then to the Fe5Si3 phase in the solution with pH 0.35. The (Nb,Ti)C/matrix interfaces are identified as the preferred site of electrochemical pitting corrosion. By exploiting the electrochemical oxidation reaction of iron in the matrix, (Nb,Ti)C powders are separated along these interfaces. The by-products of this process are FeSi alloys, which are evaluated for their electrocatalytic properties in oxygen evolution reactions. It is found that the Fe5Si3 alloy by-product exhibits good electrocatalytic activity and kinetics in the oxygen evolution reaction, demonstrating its potential for practical applications.

Processing of mineralized microgranite dike for the recovery of niobium, tantalum, and rare earth elements using 1, 2-propyleneglycol extractant

ABSTRACT A number of strategic and economic rare-metal and Rare Earth Elements (REEs)-bearing minerals were recorded in mineralized microgranite dike (MMGD) from Ras Abdah area located in the Northern Eastern Desert of Egypt. Firstly, by sulphuric acid digestion at 300 °C, 3 h, 1/3 ore/Acid ratio, the RE, Nb, and Ta present in the MMGD can be efficiently extracted into the leach solution while Zr, Fe, and Th remained in the unattacked residue. The experimental digestion proved the dissolution of 98.9, 99.2, and 96 % for Nb, Ta, and REEs, respectively. In this study, a novel method was used to selectively recover Nb and Ta content from REEs in the digested concentrate sulphate solution. Solvent extraction using 1, 2-propyleneglycol was applied for the first time to achieve this secondary recovery process. From infrared and 1H-NMR data, the extraction was achieved, and the extractant bonded to Nb and Ta through glycol and alcoholic oxygen atoms. Niobium and Tantalum ions were stripped with water for Ta and 1M HF for Nb, achieving 98.6 and 98.8 % stripping efficiency, respectively. By employing an oxalic acid precipitation technique, a precipitate of extremely pure REEs was extracted from the raffinate solutions.

Recovery of Niobium, Titanium and Yttrium from Poly-mineralized Concentrate of Gabal El- Aurf Pegmatitic Rocks, Central Eastern Desert, Egypt

Recovery of Niobium, Titanium and Yttrium from Poly-mineralized Concentrate of Gabal El- Aurf Pegmatitic Rocks, Central Eastern Desert, Egypt

Preliminary Investigation on the Thermodynamic Evaluation and Phase Evolution of Soda Ash-Assisted Roast Treatment of Alluvial Columbite for Recovery of Niobium and Tantalum

AbstractAlkaline roasting of a low-grade alluvial silica-based columbite bearing mineral from the Rayfield–Jos deposits (located in South Jos, Plateau state, Federal Republic of Nigeria) was conducted with specific emphasis on the evaluation of thermodynamic reactions as well as the mineral phase evolution during the extraction of Nb and Ta. An isothermal roasting procedure was investigated in order to understand the effects of different soda ash to sample mass ratios as well as the roasting temperatures on the measure or rate of the recoveries of Nb and Ta complexes. Thus, the feasibility rate of a successful alluvial columbite mineral roasting was determined to be influenced by certain optimal process conditions or optimum values of the study parameters, such as alkali to sample mass ratio and, more essentially, the roasting temperature. Therefore, the thermodynamic feasibility of the alkali-carbothermic roasting procedure was also investigated and the resulting chemical reactions were evaluated using the HSC chemistry 9.0 software. Premised on this, the results obtained as well as the thermodynamic data realized from the study demonstrated the feasibility of successful dissolutions of Nb and Ta into a pregnant leached-liquor stream (PLS), without the use of the conventional harmful, hazardous, toxic, and environmentally unfriendly hydrofluoric (HF) acid.

Fluoride-Free Processing of Columbite Concentrate for Selective Recovery of Niobium and Tantalum Oxides

Fluoride-Free Processing of Columbite Concentrate for Selective Recovery of Niobium and Tantalum Oxides

Exploration and physicochemical characterisation of Rayfield-Jos alluvial columbite deposit for effective mineral beneficiation and value metal recovery of niobium and tantalum

Exploration and physicochemical characterisation of Rayfield-Jos alluvial columbite deposit for effective mineral beneficiation and value metal recovery of niobium and tantalum

Work index evaluation of Rayfield-Jos columbite mineral for effective processing and recovery of niobium and tantalum

Physicalcharacterization on primary or secondary minerals is imperative. One of such physical analyses is the grindability characteristics and/or work index determination. This, as well asenergy required to comminute certain critical minerals is key and has been de-emphasized in recent time. In this regard, this study is focused on investigating the work index of alluvial columbite tailings to determine the actual energy consumed during milling to the liberation size prior to beneficiation and metal extraction. Alluvial columbite tailing test samples was sourced froman abandoned mine-field, inRayfield, Jos South,Plateau state, Nigeria.Reference mineral sample with a known grindability/work index was also utilized in this study. Reference sample was Gyel-Bukuru columbite mineral ore, sourced from Gyel town,Eastern Jos, Plateau state, Nigeria. Both test and reference samples wereground, with their weights known. 80% passing particle size were obtained for both test and reference samples. The obtained grindability values were used in determining work index of test sample. Mean work index value of ̴ 2.3041 kWh/ton was determined. Thus, this indicates that a minimum average energy amount of ̴ 2.3041 kWh was required to grind/comminute one ton ofthe alluvial ferro-columbite mineral tailing test sample. This is significant in the sustainability in processing, mining, and metallurgical engineering and especially in the columbite mineral liberation and design/development of effective mineral processing/beneficiation routes for overall efficiency of recovery, separation and extraction of value metals such as Nb and Ta. This will therefore act as a deciphering factor to be considered when choosing/selecting suitable comminution equipment and design system. The grindability data can also be utilized by the mining sector and mineral processing industries for efficient beneficiation, separation, and Nb/Ta recoveries as well as the knowledge of energy quantity consumed during mechanical activation of the mineral for effective processing or concentration.

Efficient Recovery of Niobium and Tantalum from Ferrocolumbium Tantalum by a Continuous Leaching Process Using HF − H2SO4 − HNO3 Synergistic System

Efficient Recovery of Niobium and Tantalum from Ferrocolumbium Tantalum by a Continuous Leaching Process Using HF − H2SO4 − HNO3 Synergistic System

Separation and extraction of niobium from H2SO4 solution containing titanium and iron impurities

A fluoride-free solvent extraction method for niobium separation in leached sulfuric mother liquor of ilmenorutile was proposed in this paper. The extraction system comprising trioctyl tertiary amine (N235) and 4-methyl-2-pentanone (MIBK) demonstrated good extraction efficiency and selectivity of niobium over titanium and iron impurities in sulfuric acid–oxalate solutions. Details of extraction, scrubbing, and stripping processes were investigated herein, and its practical effectiveness in both batch and multi-stage simulated counter-current modes was verified. Over 73.8% niobium was extracted under optimum conditions, and only 2.8% titanium and 1.7% iron were co-extracted. The recovery of niobium reached 99.1% in the four-stage simulated counter-current extraction tests. In the three-stage simulated counter-current stripping tests, the stripping efficiency of niobium reached 99.7% with 2.0 mol/L HNO3. Qualified niobium oxide products were prepared. The enthalpy change, entropy change, and the standard Gibbs free energy change (ΔHo, ΔSo, and ΔGo, respectively) corroborated the exothermicity, orderliness, and spontaneity of the reaction. The possible composition of the extraction complex was [NbO(C2O4)2(H2O)2]−, as supported by a Fourier transform infrared spectroscopy and ultraviolet–visible spectrophotometry. The extraction mechanism was inferred to be the outer-sphere complexation through physical binding which was the association of R3NH+ in N235 with the [NbO(C2O4)2(H2O)2]−. A preliminary mass balance indicated that 203.92 g Nb2O5 was generated from 1000 g raw material ilmenorutile.

Simultaneous Recovery of Niobium and Sulfur from Carbonate Niobite Ore with Flotation

Exploring new ways to acquire niobium resources is essential to resolve niobium supply risks, due to the fact that, at present, 99% of niobium is controlled by only two countries. In the present work, a flotation technique was applied to separate niobium from low-grade niobite ore. To maximize the utilization of the original ore resources, pre-flotation was conducted to recover sulfur and eliminate the adverse effects of sulfide on niobite flotation. The obtained sulfur grade and recovery were 33.74% and 92.04%, respectively, and its concentration ratio was 40x. As for the niobite flotation, a closed-circuit experiment with one rougher flotation, three cleaner flotations, and two scavenger flotations was carried out to achieve the maximum niobite recovery. To further improve the niobite recovery, a leaching process with diluted HCl was employed; the final obtained Nb2O5 grade and recovery were 30.19% and 65.04%, respectively, and the concentration ratio reached 242x. Moreover, the economic evaluation implies that the flotation process can attract great positive interest.

Factors and challenges in the recovery of niobium and tantalum from mineral deposits, recommendations for future development – A review

The separation and extraction of Nb/Ta metallic elements from mineral deposits have become challenging, involving complex and complicated separation process routes from the rest of the gangues/impurity elements composed in the ore mineral or deposit and from the value metals/elements themselves. Due to the presence of numerous impurities such as: refractory or metal oxides, rare earth (REE) and radioactive elements, and hence the complexity of the metal extraction process; Nb2O5/Ta2O5 are extracted hydrometallurgically from mineral deposits using hydrofluoric acid (HF) or a combination of HF and H2SO4 mineral acid dissolutions prior to extraction and recovery. Howbeit, HF’s high volatile, corrosive and toxic nature, as well as high chemical/reagent consumption, eco unfriendliness and waste generation of fluorides; contribute to Nb/Ta extraction difficulty, complexity and high equipment maintenance and/or operational cost. Also, the dangerous and non-biodegradable nature of HF to the ecosystem, health damage on inhalation of HF vapours, use of high cost corrosion resistant equipment and large complex number of operations are major constraints. As a result of these challenges, and thus the low Nb/Ta yield recovery and purity, as well as their numerous industrial applications in engineering/technology, the demand of Nb/Ta has consistently become somewhat higher than the supply. On this premise, there is need to develop fluoride-free mineral decomposition media under mild conditions as substitute/alternative extraction procedure for Nb/Ta recovery. Serious attention should also be given to mineral characterization techniques and to optimization procedures for optimum process parameters/conditions in mineral concentration and Nb/Ta extraction. This review study is therefore based on the factors/challenges relating to the beneficiation, Nb/Ta extraction and recovery from mineral deposits and recommendations for future trend/advancement.

Recovery of niobium from wastes generated in titanium production by cation exchange sorbents

This article presents the technology of niobium recovery by processing of chloride residues generated during the chlorination of titanium slags. For waste processing, a two-stage leaching technology is proposed. Water is used at the first stage of leaching and hydrochloric acid 4.0 M is used at the second stage. For the purpose of sorption of niobium from the solution composition obtained during leaching, cation-exchange sorbents Purolite-C104 and KU-2-8 H were used. By the usage of Purolite-C104 ion exchange resin the sorption efficiency of niobium from a solution with a concentration of 2 g/l was about 71.0 % (0.071 g/g) in 3.5 hours, while for KU-2-8 H ion exchange resin, sorption efficiency was about 89.0 % (0.089 g/g).

Recovery of niobium and titanium from ilmenorutile by NaOH roasting-H2SO4 leaching process

Niobium has a wide range of application in various industries such as materials, alloy, and electronic industry. To improve the use of ilmenorutile in China's Bayan Obo deposit, a novel process of extracting niobium, titanium, and iron from ilmenorutile by NaOH roasting-H2SO4 leaching process (NRHLP) was proposed. The influences of roasting and leaching temperature, roasting and leaching time, molar ratio of NaOH-to-ilmenorutile, leaching mass ratio of liquid-to-solid, and the H2SO4 concentration on the extraction of niobium were systematically investigated. The results demonstrate that this process is efficient. The optimized reaction parameters were as follows: roasting temperature, 550 °C; molar ratio of NaOH-to-ilmenorutile, 2.6; roasting time, 120 min; leaching mass ratio of liquid-to-solid, 4.0; leaching temperature, 90 °C; the H2SO4 concentration, 60 wt.%; leaching time, 2 h. Under these optimum circumstances, the maximum niobium and titanium recovery can reach 96.68%. In addition, a new phase containing niobium and titanium is confirmed and proved.

Recovery of niobium during comprehensive processing of pyrochlore-monazite-goethite ores

This paper looks at the pyrochlore-monazite-goethite ores of the Chuktukonsk deposit (0.98wt.% Nb2O5) and their processing with the help of acidbased (HNO3, H2SO4) and sulphatization techniques. Nitric-acid pressure leaching was found to be an efficient processing technique for this type of ore: ore size –0.074 mm; CHNO3 = 25%; CH2O2 = 5%; τ = 2 h; solid-to-liquid = 1:9; heat treatment mode: 1 h at 160 oC followed by 1 h at 230 oC. As a result, rare earth metals and manganese are leached to the solution while all of the contained niobium remains in the cake. Two different techniques were tested to recover niobium from the cake. One is based on the use of alkali (NaOH sintering), the other is an extractive leaching technique that combines acid leaching with liquid-liquid extraction of tributyl phosphate in one stage. It was established that niobium mi nerals can be efficiently decomposed when using a mixture of hydro fluoric and sulphuric acids with the concentrations of 4.08 and 8.46 mol/L, correspon dingly, as a leaching agent. At the weight ratio of 1:2:1 of the solid to aqueous to organic phase and after the slurry has been stirred intensively for 5 minutes, niobium fluorides, which form as a result of interaction between hydrofluoric acid and the cake components, can be recovered with a 50% solution of tributyl phosphate in octane. After that they transfer to an organic phase while impurities get accumulated in the solid residue. As niobium-containing cake has a high concentration of silicon, it is recommended to first remove silicon from the cake using a strong alkaline solution.

Occurrence Modes of Niobium in Kaolin Clay From Guizhou, China

Niobium in kaolin clay from the Late Permian sequences was reported in the range of several hundreds of micrograms per gram and was considered as a potential resource for its high concentrations and large areal distribution. Ti-bearing minerals associated with kaolin clay were identified as the main host phase for niobium in some case studies. However, the correlation between the concentration of niobium and titanium is poor, and the types of Ti-bearing minerals and modes of occurrence of niobium are not clear. Typical kaolin clay samples from the Late Permian sequences from southwest China were characterized, and the final products derived from kaolin clay sample were investigated using XRF, ICP-MS, XRD, SEM, and TEM (EDS). The results reveal that there were three types of TiO2 mineral phases in the clay samples: (a) massive TiO2 minerals and (b) aggregates of nano TiO2 minerals did not contain niobium while (c) granular TiO2 minerals were the source of niobium from the EDS analysis. The granular TiO2 minerals included anatase and rutile, both of which were the sources of niobium in kaolin clay in the current study. The findings are of great theoretical implication for source and origin study of Ti-bearing minerals and guidance for separation and recovery of niobium from kaolin clay.

Recovery of niobium and tantalum by solvent extraction from Sn-Ta-Nb mining tailings.

The slag from the extraction processes of metals from their ores may contain valuable components that, if adequately recovered, can be reintroduced in the technological life cycle. This is the case for the material obtained in Penouta mines in the North of Spain. These mineral sites are a main source of tin obtained from cassiterite. The mineral is submitted to a pyrometallurgical process to separate tin, however cassiterite is not the only mineral present in the veins, and large amounts of other minerals are normally discarded, constituting the slag. In the present case, besides cassiterite, one of the most abundant minerals in the ore is columbo tantalite, the source of the strategic coltan. In this work the raw material (slag) has been treated by acid leaching, using HF/H2SO4 as the leaching agent. Then liquid–liquid extraction of Nb and Ta was performed, with Cyanex®923 extractant, so that both metals were obtained separately. Then they were precipitated from the corresponding aqeuous solution, and calcined in order to yield Nb2O5 of 98.5% purity and tantalum salt, after calcination and purification, of 97.3% purity. The process described in this work opens a possibility to produce high quality materials that are considered critical by the EU from alternative sources exempt of criticality factors.

Selective recovery of niobium and tantalum from low-grade concentrates using a simple and fluoride-free process

The current hydrometallurgical processes used for niobium and tantalum recovery are operated in strongly acidic and fluoride-containing solutions. To avoid the use of these highly toxic media, a fluoride-free process was developed to recover Nb and Ta from low-grade industrial concentrates. The process is based on the caustic conversion of the raw material with NaOH(aq) at atmospheric pressure and at relatively low temperature which then allows the selective dissolution of sodium hexaniobates. Finally, Nb is recovered as purified hydrous oxide by acidification of the hexaniobate solution. The influence of many industry-relevant parameters (temperature, initial NaOH concentration, residence time, impurity content in the initial concentrate, pH of precipitation) was studied in order to optimize the recovery and purification of the valuable metals. Finally, the process was validated in continuous operation at a pilot scale. High recovery yields for Nb and Ta (65%) were obtained as well as high separation factors toward Ti, Fe, P, S, Th and U. The results demonstrate that it is possible to recover and purify Nb and Ta from industrial concentrates without using fluoride solutions.

Recovery of Niobium from Baogang Tailings by Carbochlorination

Carbochlorination of niobium in the tailings of Baogang concentrator was experimentally studied, and the activated carbon was used as the reducing agent and chlorine gas as the chlorinating agent. The effects of the reaction time and the temperature on chlorination rate of niobium in tailings were investigated. The result showed that when the tailings were chlorinated at 800 for 2 h,96.15% of niobium was yield.

Extraction of niobium from hydrochloric solutions with tertiary amines in aprotic diluents

Extractive recovery of niobium from concentrated hydrochloric acid solutions with tertiary amines in alkylbenzene diluents in the absence of modifiers was studied.