A number of mining companies are in the red after Australia’s prime minister said the government would require the nation's 500 largest polluters to pay a tax of A$23 per ton of carbon they produce. Australian mining company Rio Tinto (NYSE:RIO) said the tax - due to take effect in mid-2012 - will curtail investment and job creation. In early trading, Rio Tinto dropped 2.53% to $70.88, BHP Billiton (NYSE:BHP) is also down 2.50% to $93.41, and Anglo American (PINK:AAUKY) slid 3.26% to $24.30.