[priyoX]

I've been trying to make uranyl nitrate from depleted U-238, but no luck yet 
 
I've tried to dissolve scraps of the U metal in massive amounts of concentrated/fuming nitric acid, and even tried precipitating out the uranyl nitrate with ammonium hydroxide, but to no avail. Even freezing it wouldn't recrystallize it out.  Am I going wrong somewhere? I've looked all over the internet, there just doesn't seem to be enough literautre to give me clear cut details.

Can someone please point out what i've been missing or doing wrong? Is there any other method of synthesizing it from U metal?

Thanks! Much appreciate any help i can get!

Oh, just so you know, this isn't some class project. I'm a grad student trying since over 2 months to get this. Uranyl nitrate is available online, but I need to synthesize my own due to academic reasons in the lab.

Thanks again!   

[AWK]

https://carlwillis.wordpress.com/2008/02/20/uranium-chemistry/

[priyoX]

Thanks, AWK! That was a good source, but unfortunately, they dont have any info on nitrate. seems like its not an easy compound to make...

[AWK]

But this article contains information that this synthesis is not easy (though simple on the paper - synthesis of chloride and double exchange reaction with silver nitrate)