What is the name of the block of coal that supports the roof in a coal mine?

The correct term for the block of coal that supports the roof in a coal mine is "pillar." In mining operations, pillars are essential structural components that serve to hold up the overlying rock and prevent collapses. These pillars are often left in place as remnants from the coal extraction process, designed to provide stability to the mine while allowing for access to the coal seams.

Using pillars effectively balances the need to extract coal with maintaining a safe mining environment. Striking the right balance in pillar design and placement is crucial in ensuring the safety of mine workers and the integrity of the mining operation.

In this context, the other terms relate to different aspects of mining. The roof refers to the upper surface of the mine, while a rib is typically used to describe the side of the mine or the walls created during mining. "Gob" refers to the area of mined-out space which may collapse, and is not related to the structural support needed for mine safety. Understanding these distinctions is essential for anyone studying coal mining practices.