room-and-pillar

American  

[room-uhn-pil-er, room-] / ˈrum ənˈpɪl ər, ˈrʊm- /

adjective

Mining.

1. noting a means of extracting coal or other minerals from underground deposits by first cutting out rooms, then robbing the pillars between them; pillar-and-breast.

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Example Sentences

Mountain Laurel will then use the room-and-pillar mining method.

From Washington Times

“Arch expects Mountain Laurel’s per-ton costs to decline modestly and its product quality to improve following the transition. The transition will not result in the layoff of any of Mountain Laurel’s outstanding workforce, as they will be repositioned in the new room-and-pillar mine plan,” Arch said in its announcement.

From Washington Times

The statement says Arch will transition its Mountain Laurel operation in southern West Virginia from longwall to room-and-pillar mining next year.

From Washington Times

They remove the deposits with a room-and-pillar approach: using explosive blasts to loosen the salt, while leaving pillars of salt in place to support the overhead layers.

From Washington Times

The same Murray mine sparked a long legal fight over room-and-pillar mining beneath Dysart Woods, a 50-acre tract of old-growth forest owned by Ohio University about 3 miles south of Barkcamp State Park.

From Washington Times