Money transfer from China to foreign countries (Beijing)

Hello everybody.
I am desperately searching for information about money transfers from China to a foreign country, e.g. Brazil and would be very grateful if anybody could help me with an advice. As I know China is foreign exchange restricted but i don not know what happens, if our Expats in China have money left on their banc account after the assignment. Will they have possibilities to transfer this money back to Brazil? Are there restrictions regarding values etc.?

Thanks Nicola