I would not invest in most African countries, and especially in places like Guinea, and neither would Gina, I presume. RIO is well aware of the problem that could flow from hurling money at Simandou, which needs a 600K railway to be viable, so it is looking for investment partners to risk the funding - see http://www.ft.com/intl/cms/s/0/8592d3d2-8e55-11e3-98c6-00144feab7de.html#axzz38wxlg9wx
The Chinese will want that ore because of its quality, and as a bargaining chip to keep Australian ore cheap. The Chinese have a history of investing in corrupt environments in Africa, so the mine could one day start exporting, and flood the market with high-quality iron ore. If a few people are killed fighting over the spoils, that would not be a show stopper for the Chinese.