High-angle-mining system. Task report: definition of system requirements. [Reserves suitable for auger mining]

Technical Report · Mon Dec 01 04:00:00 EST 1980

DOI:https://doi.org/10.2172/6557212· OSTI ID:6557212

Brown, E. G.

The commonly accepted limits for conventional highwall coal augering are seam thickness from 2 to 8 ft, a pitch less than 10/sup 0/, and a penetration depth of 150 to 200 ft. Recovery ratios for these conditions vary from 25 to 50%. One source found, for a limited sample base, an average recovery ratio of about 35%. The factors contributing to recovery losses were noted to be the following: Undersize augers for the seam being mined, hole depths less than maximum obtainable, and excessive spacing between holes. An attempt was made to determine the reserves available for auger mining by reviewing the literature. The augerable reserve base for horizontal seams (0 to 10/sup 0/) between seam limits of 2 to 8 ft for a penetration depth of 200 ft has been estimated at 5 billion tons. An equivalent value estimated for coal residing in steeply pitching seams (25 to 90/sup 0/) is 234 million tons for a penetration depth of 150 ft (or 312 million tons for 200 ft). While no similar value for moderately pitching seams (10 to 25/sup 0/) has been found, most of the information necessary to make such an estimate exists. Recovery ratio, hole size, and spacing, to a large extent, depend on geological factors affecting highwall face integrity and coal competency. The thicker the seam, the more difficult it becomes to achieve high recovery. Narrow and high-ceilinged excavations, coupled with small face openings, appear feasible in competent coal and may be the most promising approach to improve recovery. Another approach to improve recovery is to structurally fill the excavation with a water, crushed rock, and limestone mixture. The cost of this must be weighed against the additional amount of coal recoverable.

• Research Organization: FMC Corp., Santa Clara, CA (USA). Engineered Systems Div.
• Sponsoring Organization: USDOE
• DOE Contract Number: AC01-80ET14257
• OSTI ID: 6557212
• Report Number(s): DOE/ET/14257-T1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
AUGER MINING
COAL DEPOSITS
COAL RESERVES
COAL SEAMS
DATA
DIMENSIONS
GEOLOGIC DEPOSITS
GEOLOGIC STRATA
GEOLOGIC STRUCTURES
INCLINED STRATA
INFORMATION
LOSSES
MINERAL RESOURCES
MINING
NORTH AMERICA
NUMERICAL DATA
RESERVES
RESOURCES
THICKNESS
USA