Nothing goes on in China without the government having their hands in it.  Probably they support the project just can't say so publicly otherwise they would shut it down completely already.  As was reported, power companies using excess energy toward mining and are probably some of the biggest miners in the world.  And of course China is dominating the world in terms of mining output. 
President Xi made the promise to double GDP/capita from 2010-2020 and they are on track and as long as this project remains in line with the goals of the party.  I'm speculating but I don't think the government will want to lose such a promising opportunity in the Mainland to someplace like Sinagpore, Hong Kong or Taiwan.