LA Times: Its gray and black walls stretching to infinity, Latin America’s largest coal mine resembles a miniature Grand Canyon. The big difference is that the timeless hand of nature has not carved out El Cerrejon mine. Booming global demand has. A fleet of electric shovels runs 24 hours a day scooping up 50 tons of coal at a swipe. The rock is loaded onto 100-car trains that roll nine times a day to a private Caribbean port, where it is placed on cargo ships that deliver it to power …