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Pat Quinn, Governor |
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Methods of Underground Coal MiningBRP: Blind Room and Pillar In this method, the rooms are 15-25 feet wide and 200-300 feet long. Pillar width is 25-60 feet for ordinary room pillars, 80-120 feet for blind room pillars, and 100-150 feet for barrier pillars. Panel extraction ranges from 50 to 65%.
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