bus from Changji to Urumchi Airport

I am in Changji now and tommorow mid nigt I will fly back home.
I asked for a bus to the airport in the hotel but nowbody knows. ( and English is not spoken )
As my flght is very late and I have a lot of time to spend, I wouldn't like to use a taxi.
When I arrived at the airport a few days ago, I saw a minibus to Changji in front of Terminal 3 arrivel
Please kindly infrom me where I can catch a bus to Urumchi Airport.
Thanks.