The Colombian government has toughened its stance over US coal miner Drummond, by halting loading of coal at its port until the company can comply with new environmental rules…[It was] decided to suspend loading until a new system was put in place, said Luz Helena Sarmiento, environment minister…“In case Drummond breaks the law again, we will be forced to act as police, and that will aggravate its situation,” she added…The new rules, which took effect on January 1, stipulate that coal exporters load ships using conveyor belts instead of by barge and crane, thus preventing spillage into the Caribbean…Colombia’s coal sector experienced a turbulent 2013, with long strikes at both Cerrejón and Drummond, as well as supply disruptions including bombing of rail lines by leftwing rebels...