Ghambi, S, Sanchez-Segado, S, Chipakwe, V et al. (1 more author) (2021) An investigation on hydrofluoric (HF) acid-free extraction for niobium oxide (Nb2O5) and tantalum oxide (Ta2O5) from columbite/tantalite concentrates using alkali reductive roasting. Minerals Engineering, 173. 107183. ISSN 0892-6875
Abstract
Tantalum, niobium, and their oxides are important precursor materials, essential for high-temperature alloys and electronic devices. The primary hydrometallurgical extraction technique to extract tantalum and niobium from minerals involves hydrofluoric acid (HF) digestion of the concentrates, followed by solvent extraction as an oxide separation and purification step. 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% Ta2O5 and 16% Nb2O5). In this process, the concentrates are reduced using carbon and alkali in the temperature range of 800–950 °C, which helps in reducing and magnetically separating the iron oxides present in the concentrates as metallic iron. 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 using oxalic acid leaching, followed by sodium bisulphate roasting.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Tantalum; Niobium; Carbothermic reduction; Roasting; Tantalite minerals |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Funding Information: | Funder Grant number NERC (Natural Environment Research Council) NE/M01147X/1 EU - European Union 331385 NERC (Natural Environment Research Council) NE/L002280/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 07 Sep 2021 10:59 |
Last Modified: | 25 Jun 2023 22:45 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.mineng.2021.107183 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:177840 |