What are the main methods of mining? | American Geosciences .There are four main mining methods: underground, open surface (pit), placer, and in-situ . Coal Mining and Transportation (Webpage), U.S. Energy Information.who is main for coal mine,Glossary of Mining Terms - Kentucky Coal EducationAuxiliary operations - All activities supportive of but not contributing directly to mining. Auxiliary ventilation - Portion of main ventilating current directed to face of.
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