Is anyone up to date on
extractive metallurgy of Nb and Ta from mixed ores - my reading suggests it is more difficulty than simple production of ferro-niobium for the steel industry. However it is by no means impossible, and because of the exceptional value of the metals it will certainly be economical for ores of good grade.
1. There is a lot of talk on this source -
https://www.sciencedirect.com/science/article/abs/pii/S0892687522005271
2. And here, a bit more practical
https://www.britannica.com/technology/niobium-processing
3.
What I would really like to know is whether we actually need to separate out the Ta as a separate product. Sure it is more valuable (capacitor use) but the main thrust of mining these ores is for the niobium for steel benefaction and for the next gen lithium ion battery. So would an alloy of Nb and Ta and Ti work as well (or better) than Nb and Ti alone as the cathode of the Li ion bttery.
[The grains of the Nb -Titanium alloy have a crystal structure which allows the much smaller Li atom spaces to hide away and pathways for the Li ion to 'getaway' and conduct the electricity - Ta is an atom which has size and electrical and chemical properties almost exactly the same as Nb, This is the reason they are so hard to separate, but I reckon they could act together in a battery, maybe even better than Nb alone !!!]
4. The huge benefit of the Nb battery is that the growth of Li dendrites as the Li is redeposited on the surface of the cathode is prevented, and so eliminates the risk of short circuit and fire. Also because of the Nb-Ti alloy's relative strength, swelling and shrinkage (which physically destroys the battery over its life) is reduced. Similar ideas apply to the anode, but graphite anodes are pretty good at absorbing the Li ions (the graphite is spheriodised to allow space to swell, and coated with a bituminous material to give the anode some sponginess) so those same problems are lesser, but not completely eliminated. The literature says Nb can improve matters on the anode too, but is less specific, suggesting mainly that the anode particles be coated with a layer of Nb metal, to provide strength because of Nb's great strength and ductility.
5. This is the future, and Nb and possibly its twin atom Ta, could be the ones to be the main players in low weigh, long life, fast charging, safe batteries to power it.
Please comment, and share your research.
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