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

See Examples For:

room-and-pillar

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

From Washington Times ● Feb. 20, 2019

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 ● Feb. 14, 2019

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 ● Feb. 17, 2017

Theirs is a room-and-pillar mine, in which natural pillars are left during the coal removal to support the roof, some of which are later removed.

From New York Times ● Apr. 23, 2010