unless they mean to declare war against bitcoin and use the military with tanks on the streets they will not be able to close down mining operations. it was discussed before, in China mining farms are feeding a lot of people on different levels and at different posts. from normal people to government officials. you can't close down such operations, nobody will let you do it!
I don't think the Chinese government couldn't care less about the unemployment that getting rid of Bitcoin mining could generate.. given past precedents. China doesn't care about their citizens that much, and I don't think mining creates a lot of jobs, it may create some jobs, but it wouldn't be a disaster.
The question here is, what does China gain from mining Bitcoin and what does it lose? If they are smart, they should understand by now the importance of your country being the leader mining force in the future of finance.. so like I said, I wouldn't be surprised if they eventually ban Bitcoin in China WHILE still allowing mining.