What is the role of ammonium bifluoride (ABF) in the extraction of tantalum (Ta) and niobium (Nb) from coltan-bearing ore?

Label:chem

Topic
Ammonium bifluoride (ABF, NH4F·HF) is a strong fluorination agent used in the extraction of transition and refractory metals like tantalum (Ta) and niobium (Nb). It is known for its reactivity similar to that of fluorine and hydrofluoric acid (HF), but it is safer to transport and handle. ABF is non-volatile at room temperature and environmentally safe. It is relatively inexpensive and can be recycled from gaseous compounds.
Answer
Ammonium bifluoride (ABF) is used as a fluorination agent to pre-treat coltan-bearing ore, converting the Ta and Nb oxides into water-soluble ammonium fluorides. This process enhances the subsequent sulfuric acid leaching efficiency, allowing for high recovery rates of Ta and Nb. The optimal conditions for this process include an ABF-ore mass ratio of 5/1, a fluorination temperature of 200°C, and a fluorination duration of 2.5 hours, resulting in about 94% recovery of Ta and 95% recovery of Nb.
Return to Home Chemical List
Knowledge you may be interested in
What are the new compounds isolated from the roots of Stemona tuberosa, and what are their structures? What is the effect of zeolite topology on the hydrocracking pathways of 9,10-dihydrophenanthrene (9,10-DHP)? What are the structure-activity relationships (SAR) of the 9,10-dihydrophenanthrene derivatives? How were the 9,10-dihydrophenanthrene derivatives synthesized and tested for their inhibitory activity? What are the 9,10-dihydrophenanthrene derivatives, and what is their role in treating COVID-19? What is the larvicidal effect of sodium hypochlorite on juvenile Aedes aegypti mosquitoes? How effective is copper sulfate pentahydrate as a larvicide against juvenile Aedes aegypti mosquitoes? What is the efficacy of silver nitrate as a larvicide against juvenile Aedes aegypti mosquitoes? How does the coordination crosslinking network formed by CSP affect the morphology of the NBR/clay/CSP nanocomposites? What is the significance of clay in the NBR/clay/copper sulfate pentahydrate (CSP) nanocomposites? How does the particle size of coltan ore affect the recovery of tantalum (Ta) and niobium (Nb) during the fluorination process? What is the role of sulfuric acid in the leaching process after fluorination of coltan ore? What is the role of sulfuric acid and ferric sulfate in the leaching process of silver and copper from photovoltaic waste? How does the concentration of sulfuric acid and ferric sulfate affect the leaching efficiency of silver and copper? What are the environmental advantages of using sulfuric acid and ferric sulfate over nitric acid in the leaching process? What is the role of pyronaridine tetraphosphate in treating infections caused by highly pathogenic coronaviruses such as SARS-CoV-2, SARS-CoV-1, and MERS-CoV? How does pyronaridine tetraphosphate compare to other antiviral treatments like molnupiravir and nirmatrelvir in terms of efficacy against SARS-CoV-2? What is the mechanism of action of pyronaridine tetraphosphate against SARS-CoV-2 and other coronaviruses? What is the role of the dimeric salen ligand derived from L-tartaric acid in the asymmetric addition of trimethylsilyl cyanide to aldehydes? How does the Ti-salen complex derived from the dimeric salen ligand perform in the asymmetric addition of trimethylsilyl cyanide to various aldehydes?