A system for breaking down coal by which compressed air, generated locally
by a portable compressor at 10,000 psi (69.0 MPa), is used in a releasing
cylinder, which is placed in a hole drilled in the coal. Thus, slow
breaking results, with no flame, in producing a larger percentage of lump
coal than is made by using explosives. Its principal advantage is that it
may be used with safety in gaseous and dusty mines.
See also: compressed-air blasting
Dictionary of Mining, Mineral, and Related Terms