An analysis of appropriateness of room-and-pillar method for extracting medium-thick inclined coal seams in Quang Ninh Coal Basin taking into account existing mining and geological conditions was carried out. Corresponding foreign experience of applying room-and-pillar method was considered in relation to the mines of Vietnam. Process flow sheet of first mining and extraction of mediu... https://fitnessgravesyardes.shop/product-category/crankshaft-bearings/