By analyst By Cecilia Jamasmie Mining giant Rio Tinto (ASX, LON:RIO) has agreed to sell its Kestrel coal mine in Australia to private equity manager EMR Capital and Indonesian coal company Adaro Energy, in a deal worth $2.25 billion. The transaction makes of Rio Tinto the first major miner to exit the coal industry, and comes only a week after it announced the $1.7 billion-sale of its Hail Creek Mine, also in Australia, to Glencore, as well as an undeveloped project in Queensland to Whitehaven Coal for $200 million.