You can extract argon from air to do most of what helium is used for. It's completely inert and liquefies at 87K. Pure argon gas costs $5 a kilo. Liquid nitrogen and carbon dioxide will cover most of the rest of the applications and are much cheaper.
Neon from air is much more expensive at $300 a kilo. That's because Neon is at a low concentration similar to helium. Helium can be extracted for about the same price as neon, so we're not in danger of ever running out. Helium is a renewable resource that leaks out of the Earth's crust and regenerates from solar wind constantly, contrary to op.
It's only extremely cheap helium that will run out, and most of the supplies in the world are still underground in natural gas reserves. There are generations of cheap helium left.
No, it's not just that you "can" extract argon from the air, it's that we do, a lot. It's widely industrially available. If Argon were a suitable replacement for Helium it would be used instead due to its vastly lower cost, wider availability, and easier handling.
From this we can conclude that Argon is not a suitable replacement for the current uses of Helium. People pay a premium to use Helium today, and that speaks to the fact that Helium has unique properties that are highly advantageous.
He costs $3 per m^3 on the open market. Argon costs about $8 per m^3. N2 is cheaper.
There are some uses for He that are harder to replace. Argon will collect in low spaces more than He; N2 might be a compromise for welding. Nothing can be relied on to be quite as cold as liquid He. But there is a lot of substitution that can be done when He prices rise, several generations from now.
Dude. 87K =/ 4K. 87K>77K. That means its worse than nitrogen, which is dirt cheap and fairly useless for serious cooling. Even run-of-the-mill superconductor magnet cooling is a stretch for nitrogen, let alone exploration and exploitation of more exotic quantum effects.
Neon from air is much more expensive at $300 a kilo. That's because Neon is at a low concentration similar to helium. Helium can be extracted for about the same price as neon, so we're not in danger of ever running out. Helium is a renewable resource that leaks out of the Earth's crust and regenerates from solar wind constantly, contrary to op.
It's only extremely cheap helium that will run out, and most of the supplies in the world are still underground in natural gas reserves. There are generations of cheap helium left.