The South African consortium distanced itself from allegations that it is linked to the Gupta family, the previous owner of Optimum coal and other two assets.
The fall in iron ore purchases for 2018 came as a 70 percent plunge in profit margins since late October cut the incentive for steelmakers to ramp up output and restock raw materials.
According to the new EPA analysis, the costs of complying with the rule are projected at $7.4 billion to $9.6 billion annually, while monetized benefits are estimated to be $4 million to $6 million annually.
Study shows mining has sparked "unparalleled inorganic compound diversification" like rabbittite at Lucky Strike, Utah and a handful found on smelter walls