is there a fast train from Zhengzhou to Jingdezhen and return?

There is no train between the two places, let alone the fast train, so it is suggested to transfer in Nanchang city.
From ZZ to Nanchang, seven trains exist and between Nanchang and Jingdezhen, there are one train. If you want to use the train, booking in advance is highly recommended.

i thank you for your information... Yes Jingdezhen is a very awkward city to get to... its either 24 hours from Beijing,,, or 18 hours from Zhengzhou...
Do you know if there is a bus service from Wuhan to Jingdezhen?

Yes, there is bus service from Wuhan to Jingdezhen. You can take a direct long-distance bus at Wuhan Jinjiadun Bus Station. Buses are scheduled at 07:20, 09:30, 14:30 and 16:30. It takes around 5h and costs CNY178 per peson.