My group intend to take the K452 from Chengdu to Urumqi. We want to break up the journey as it is too long a ride! Which city or cities would you recommend for us to stay?

It is suggested to stay at Zhangye, Jiayuguan and Liuyuan Stations. For Liuyuan, you can head for the Dunhuang for a short visit.

Thanks Linda. Arrival time for Zhangye and Jiayuguan is not convenient. What about Baoji, Zhongwei and Liuyuan?

To be honest, there are only a few places to see, so it is not suggested to go.
Zhongwei is much better and the local Shapotou is recommended, because it is a great place for enjoy the desert scenery.
Liuyuan is close to Dunhuang, so it is also highly recommended.
If the time is not possible for covering both the Zhongwei and the Dunhuang, I suggest you to go to Dunhuang only and I am sure you will not feel regret.