Transfer and layover in Urumqi

I am a Georgian citizen traveling from Beijing to Astana, Kazakhstan (I have a single entry Chinese visa and the 24-72 h visa-free transit does not apply to me). I have a layover in Urumqi for 22 hours. So my question is will I have to go through the final passport control (immigration checkpoint) in BJ or in Urumqi on the way to Kazakhstan.
Thank you