There is a real shortage of expertise in mining. Also, there is a fine line between being a profitable thriving business and just barely getting by and then in losing money. With all of the investments and expertise required, I don't think the government could even scratch the surface of profitability as a nationalized company.
In fact the track record in regard to oil for nationalized companies is poor. That is one of the real reasons we are facing higher oil prices and shortages around the world.