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Underground Mine Tests of Ream.

PB267340

Publication Date	1976
Personal Author	Lundquist, R.
Page Count	46
Abstract	Ream is a unique method of rock breaking using high energy projectile impact. This report describes the most recent in a series of tests demonstrating mining applications for the ream method. In an underground limestone mine at Greer, W. Va., ream was used to drive a short tunnel and drill a large diameter borehole. Along with breakage data from these tests, the goal of the program was to examine environmental problems which might result from the use of cannons underground. A total of 103 shots was used to advance a 14-1/2-feet high by 10-feet-wide face a distance of 5-1/2 feet. It is estimated that the 9.3-pound-concrete projectiles launched at 5,000 feet per second will break an average of 0.78 tons of limestone or 67 percent of the 1.125 tons of granodiorite broken in previous tests. The 9-inch-diameter borehole was drilled horizontally by repeated axial impact for 7 feet, 2-1/2 inches by 21 shots giving an average of 4.12 inches per shot. Scaling this result to compressible impact energy yields an estimated 5.8 inches per shot for a 12.8-inch diameter hole compared with 8 inches per shot for a 16-inch-diameter hole in granodiorite.
Keywords	Tunneling(Excavation) Rocks Breaking Guns(Ordnance) Hypervelocity projectiles Hypervelocity impact Drilling Boreholes Feasibility Mufflers West Virginia Rapid excavation and mining REAM guns Greer(West Virginia)
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 79G - Guns
Corporate Authors	Physics International Co., San Leandro, Calif.; BUREAU OF Mines, Washington, D.C.
Document Type	Technical Report
Title Note	Final rept. Jan-Apr 76.
NTIS Issue Number	197718
Contract Number	H0252011

Underground Mine Tests of Ream.

Underground Mine Tests of Ream.
PB267340

Publication Date	1976
Personal Author	Lundquist, R.
Page Count	46
Abstract	Ream is a unique method of rock breaking using high energy projectile impact. This report describes the most recent in a series of tests demonstrating mining applications for the ream method. In an underground limestone mine at Greer, W. Va., ream was used to drive a short tunnel and drill a large diameter borehole. Along with breakage data from these tests, the goal of the program was to examine environmental problems which might result from the use of cannons underground. A total of 103 shots was used to advance a 14-1/2-feet high by 10-feet-wide face a distance of 5-1/2 feet. It is estimated that the 9.3-pound-concrete projectiles launched at 5,000 feet per second will break an average of 0.78 tons of limestone or 67 percent of the 1.125 tons of granodiorite broken in previous tests. The 9-inch-diameter borehole was drilled horizontally by repeated axial impact for 7 feet, 2-1/2 inches by 21 shots giving an average of 4.12 inches per shot. Scaling this result to compressible impact energy yields an estimated 5.8 inches per shot for a 12.8-inch diameter hole compared with 8 inches per shot for a 16-inch-diameter hole in granodiorite.
Keywords	Tunneling(Excavation) Rocks Breaking Guns(Ordnance) Hypervelocity projectiles Hypervelocity impact Drilling Boreholes Feasibility Mufflers West Virginia Rapid excavation and mining REAM guns Greer(West Virginia)
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 79G - Guns
Corporate Authors	Physics International Co., San Leandro, Calif.; BUREAU OF Mines, Washington, D.C.
Document Type	Technical Report
Title Note	Final rept. Jan-Apr 76.
NTIS Issue Number	197718
Contract Number	H0252011