Good morning /sci/, who feels like flexing their inorganic chemistry muscles a little?

I am a non-chemist trying to make uranyl nitrate ($UO_{2}(NO_{3})_{2}$) by dissolving uraninite ($UO_{2}$) in nitric acid. The dissolution was successful, now I need to isolate my desired compound. In case you're wondering, I want it because it's fluorescent.

Here's what I have done so far:

- Dissolved the ore in 65% nitric acid
- Removed insoluble minerals
- Precipitated alkaline earths using sulfate (This concentrated a lot of the radioactivity in the precipitate)
- Precipitated the uranium using ammonia (forming insoluble ammonium diuranate)
- Filtered and washed the precipitate
- Redissolved the uranium using nitric acid
- Let the solution dry in air for months, losing interest in it for a while

The solution crystallized partially, which is where I got pic related. Both the solution and the crystals are emitting a considerable amount of beta-radiation, indicating the presence of $^{210}Pb$.

I have access to mineral acids, hardware store grade solvents and very little glassware. Does anyone want to suggest a next step? Thank you very much!