Nope, separation between different Uranium isotopes is achieved by centrifugation (of a gaseous form). Pretty much every time where you have something that has identical chemical/physical properties outside of a differing molecular weight, centrifugation is the way to go if you want to do it quantitatively.

Well, you’re wrong, but okay.

Historically, the two uranium enrichment methods that have operated on a commercial scale are gaseous diffusion and the gas centrifuge. Gaseous diffusion was the first commercial enrichment process, but it is energy-intensive and has been replaced by centrifuge technology in commercial use.[5] The last large commercial gaseous diffusion plant, the Paducah Gaseous Diffusion Plant in the United States, ceased enrichment operations in 2013.[22]

In the mid-2020s, commercial uranium enrichment is performed by gas centrifuge plants

https://wikipedia.org/wiki/Enriched_uranium#Enrichment_methods

What if I just combine it with gas (petrol) instead?

Nuke speedrun any%