The Anglo American unit which had enjoyed sky-high iron ore prices in the past now faces a decline in profits as the metal price drops.
Rio Tinto's Namibian miners are said to be dying of cancers after extracting uranium ore for the British and US military in the 1970s.
Around 200 NUM members have marched to the Mining Indaba in Cape Town to protest against the ill-treatment of Rio Tinto miners in other countries.
A Bill, which must first gain parliamentary approval before being signed into law, has proposed levies on mining companies.
Miner Rio Tinto has suspended coal exports from Mozambique's north-west Tete province after threats by the opposition party Renamo, says an official.
Rio Tinto will keep its diamond businesses after failing to find a buyer and deciding not to pursue an initial public offering of the unit.
The mooted merger between commodities trader Glencore and mining company Xstrata is likely to face few regulatory hurdles in South Africa.
Botswana, the world's largest diamond producer by value, is now doing with its diamond mining industry what SA failed to achieve for a century.
The taking of shares from foreign company by the Zimbabwean government could have a positive effect for Robert Mugabe where votes are concerned.
BHP Billiton tightening the screws on its local business associates.
The ANC is pondering a windfall tax as a less risky way to maximise benefits from minerals, writes Kevin Davie.
Zimbabwe is due to probe firms to establish their level of compliance with a law that forces them to sell at least 51% of shares to Zimbabwe locals.
Demand for iron ore, copper and aluminium will double in the next 15 to 20 years, driven by the Brics economies, says Rio Tinto's chief executive.
Rio Tinto and Anglo American have said they plan to sell their stakes in Palabora Mining, SA's only refined copper producer.
Zimbabwe's Parliament has declared that Mugabe-backed regulations seeking to nationalise foreign companies are "unconstitutional ... and absurd".
Resources group Rio Tinto has said that it extended its $4-billion offer for Riversdale by another two weeks.
Resources group Rio Tinto said on Friday that it would seek to delist Riversdale following the end of its takeover bid.
Zimbabwe is considering legislation to force miners to fund development in local communities, a state-owned newspaper said on Tuesday.
Rio Tinto has offered $3,9-billion to buy Australian-listed coal miner Riversdale in an agreed deal.