Air quality impact assessment of multiple open pit . - ScienceDirectSep 21, 2011 . The coal mining region in northern Colombia is one of the largest open pit mining regions of the world. In 2009, there were 8 mining companies.open pit multiple,open pit multiple,Short Term Scheduling in Open-Pit Mines with Multiple Objectivesan open-pit mine, in which several objectives, of varying priority, characterise . logical regions containing multiple types of material (eg. high grade, low grade,.
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