Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the mineral phase ...

Columbite-(Fe) is a post-magmatic accessory mineral occurring within syenogranites and greisens from the Desemborque Pluton. The petrographic (SEM) and geochemical (EPMA and LA-ICPMS) examination of this mineral shows two distinct textural types within both the rocks, named columbite-1 and columbite-2. The columbite-1 type …

Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the mineral phase. …

The criteria for a mineral to belong to the columbite supergroup are: the general stoichiometry MO 2; the crystal structure based on the hexagonal close packing (hcp) of anions (or close to it); the six-fold coordination number of M-type cations (augmented to eight-fold in the case of slight distortion of hcp); and the presence of zig …

The remaining residue is rich in alkali complex (e.g., sodium tantalates and niobates) formed during the roasting process which was reclaimed as a purified mixture of oxides of Nb2O5 and Ta2O5, by ...

Columbite has the same composition and crystal symmetry (orthorombic) as tantalite. In fact, the two are often grouped together as a semi-singular mineral series called columbite-tantalite or coltan in many mineral guides. However, tantalite has a much greater specific gravity than columbite, more than 8.0 compared to columbite's 5.2.

Since 2006, our working group has been investigating columbite-tantalite (coltan) mineralisation, especially in Africa, also within the wider framework of establishing certified trade chains.

Contact angles on columbite were investigated, at three concentration levels of quaternary amine chloride 2.5, 12.5, and 250 mg per liter. No contact was obtained on columbite with 250 mg per liter collector concentration at pH levels of 2, 4, or 6. Double layering of the collector on the mineral surface may be the reason for this effect.

The gravity separation takes advantage of the high density of the Ta-bearing phases, with specific density in the range 6 to 8. − Selective reverse flotation to concentrate the finest material − Low and high intensity magnetic separation to remove companion magnetic phases. − Thickening circuit to recycle the process water.

PROCESSING OF COLUMBITE-TANTALITE ORES AND CONCENTRATES FOR NIOBIUM AND NIOBIUM COMPOUNDS IN ELECTRONIC APPLICATIONS. Dr. …

Columbite-to-pyrochlore conversion is proposed to enhance the difference of physicochemical properties between niobium minerals and gangue minerals with the aim of improving the niobium minerals processing of Bayan Obo deposit. Columbite mixed NaF and CaF2 can be converted into pyrochlore by solid-state reaction. The effect of …

The conditions of tantalite (Congo deposit) and the decomposition of columbite (Zashikhinsk deposit) using an HF and H2SO4 mixture when heated to 80°C have been found. The extraction of Ta and Nb into solutions achieved levels of more than 99% and ∼94% for tantalite and columbite, accordingly. It has been found that operation …

A 0.8PMN–0.2PT solid-solution ceramic was synthesized by columbite processing technique. The effects of sintering temperature on the density, structure and microstructure and in turn on the dielectric properties were investigated. The ceramics sintered at and above 1050 $$^{circ }hbox {C}$$ ∘ C resulted in single-phase perovskite formation. ...

of. (6) Niobium metal is made when Nb2O5 and carbon black are mixed, pressed into pellets and reduced in a two-step process to niobium metal in a vacuum furnace (direct reduction). During the first stage the oxide is present in a stoichiometric excess up to 15% over the stoichiometric proportions.

During the Columbite- (Fe) leaching process, FeNb 2 O 6 reacted with the concentrated sulfuric acid solution. In the presence of H +, the bond Fe-O, Nb-O in the ferrocolumbite surface could break, and the -SO 4 bond would replace O in the bond Fe-O, Nb-O and form the bond of Fe-SO 4, Nb-SO 4.

indonesian mining journal vol. 21, no. 1, april 2018 : 9 - 19 processing of a nigerian columbite- rich ilmenite ore for improved industrial application by sulphuric acid solution pengolahan bijih kolumbit-kaya ilmenit dari nigeria untuk aplikasi industri menggunakan larutan asam sulfat 1 1 2 alafara a. baba, sunday o. jacob, daud t. olaoluwa, …

Columbite is the mineral concentrating Nb, Ta and Y-group elements. It forms both large (2–5 mm) and small (smaller 0.5 mm) black grains, in places it occurs …

Columbite is the main important mineral form of niobium. The columbite ore dressing usually involves pre-concentrate and concentrate clean-up. In order to recover columbite, a flowsheet which combines magnetic with gravity processing has been found suitable [3].

DOI: 10.1007/s42461-024-00969-5 Corpus ID: 268672576; Fluoride-Free Processing of Columbite Concentrate for Selective Recovery of Niobium and Tantalum Oxides @article{Tanvar2024FluorideFreePO, title={Fluoride-Free Processing of Columbite Concentrate for Selective Recovery of Niobium and Tantalum Oxides}, …

This paper focuses on processing technologies for the exploitation and purification of Nb and Ta from primary and secondary ore sources that have been used …

Published Date：24 November 2023. JXSC has designed a complete Flowchart and provides a complete set of processing plant machines & all accessories for Brazil's customer alluvial gold & columbite processing plant in Brazil. The client has their engineering team set up this plant, so there is no requirement for our engineering site …

@article{Nzeh2023WorkIE, title={Work index evaluation of Rayfield-Jos columbite mineral for effective processing and recovery of niobium and tantalum}, author={Nnaemeka Stanislaus Nzeh and A. P. I. Popoola and Daniel Okanigbe and S. O. Adeosun and Abraham Adewale Adeleke}, journal={Materials Today: Proceedings}, year={2023}, …

Solvent extraction, on the other hand, releases organic solvents which are lost irreversibly via natural evaporation during the process. This research demonstrates a novel chemical process for the extraction and refining of columbite and tantalite concentrates (29% Ta 2 O 5 and 16% Nb 2 O 5). In this process, the concentrates are reduced using ...

The binary niobate ceramics, with the formula M 2+ Nb 2 O 6 where M 2+ =Ca, Mg, or a transition metal (TM), have the orthorhombic columbite structure. The best-known members of this group are zinc niobate (ZnNb 2 O 6) and magnesium niobate (MgNb 2 O 6), but Ca, Co, Ni, Mn, Cu, Cd, and Fe 2+ cations can also be included in the …

New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. The REE geochemistry was studied by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five major types of chondrite-normalized REE distribution patterns are …

The extraction of these two metals from columbite-tantalite ore is based on generic extractive metallurgy. However, the upstream purification of ore and downstream extraction of Ta and Nb remain a ...

In the case of a binary mixture of a paramagnetic and a ferromagnetic material the trend of magnetisation as a function of applied magnetic field strength will be a combination of both materials (as shown in Fig. 2) (Waters et al., 2007).If the slope (or susceptibility) of the linearly sloped portion of the binary mixture trend is extracted and …

Towards sustainable processing of columbite group minerals: elucidating the relation between dielectric properties and physico-chemical transformations in the …

Dissolution practices contain acid and alkali leaching. Leaching of columbite-tantalite ore to convert Ta and Nb oxides into intermediate compounds is a twofold …

The result of HPEMP processing (t treat = 100 s) resulted in such additional defects as erosion pits on the columbite and tantalite surfaces (Fig. 1c). Fig. 1 SEM micrographs of a – c columbite, d, e tantalite, and f zircon surfaces a, d before and b, c, e, f after exposure to a high-power nanosecond electromagnetic pulses ( t treat = 50 ...

In contrast as regards to the under-size and over-size particles, the products realized after the milling process of the test columbite tailings sample had just about 1.22% cumulative mineral particles retained on the 425 µm sieve with about 98.78% cumulative particles passing through the sieve. About 2.03% of the mineral sample …

Phonon spectra of a, b anatase, c, d rutile and e, f columbite for a, c, e pristine and b, d, ... Third, the fraction of the columbite phase significantly increases with the application of shear strain through the HPT process, and the maximum columbite fraction (~ 70 wt%) is achieved for the sample processed by HPT for 15 turns. ...

Columbite group minerals can be described by the general chemical formula AB 2 O 6, with the A sites occupied by elements such as Mn 2+ and Fe 2+, and the B sites filled by elements like Ta 5+ and Nb 5+ . The industrial process for metal extraction from columbite group minerals highly depends on fluoride chemistry.

Columbite-tantalite-bearing granitoids of the Eastern Desert province of Egypt can be categorized into: (i) metaluminous alkali granites; (ii) peraluminous Li-albite granites; and (iii) metasomatized biotite and/or muscovite granite (i.e. apogranites). Columbite of the alkali granite is of FeNb 2 O 6 composition and associated with annite. The ...

Columbite is a mineral composed of iron, manganese, niobium, and tantalum. The final product derived from columbite depends on the specific processing methods applied and the intended use. One of ...

2.. Materials and methodsAt the Jos Plateau, Nigeria (Fig. 1), portable survey meters (a 2.5-cm × 2.5-cm NaI(Tl) detector and an Atomtex dosimeter) were used for in-situ radiation measurements in the field.Three sites at the tin mine were surveyed to identify study locations. A tailing dump ground showed highest values and thus was chosen to …