Underground coal mining — using longwall and room-and-pillar methods — produces higher-BTU, lower-moisture metallurgical and thermal coals, particularly from Central Appalachian seams prized by steel mills. Operational costs are higher than surface methods, and mine safety regulations under MSHA add compliance layers that affect production continuity. Metallurgical coal from underground US mines competes globally with Australian and Canadian supply, making quality certification and consistent seam characteristics central to export contract negotiations.

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