coal barrier

coal barrier

[′kōl ‚bar·ē·ər]
(mining engineering)
A protective pillar composed of coal.
References in periodicals archive ?
It recommended that they jointly pursue the issue of outcrop coal barrier width and overburden thickness and its competencies and develop minimum standards.
This minimal thickness of solid coal barrier combined with the continually increasing hydrostatic pressure as a result of the rising slurry level resulted in piping erosion of the barrier and eventually breakthrough of slurry into the mine workings," the Triad Engineering report said,