Innovative tailgate support for heavy ground: 11 left longwall panel, Cyprus Shoshone Mine
- Fosroc Inc., Grand Junction, CO (United States)
- Cyprus Shoshone Coal Co., Hanna, WY (United States)
Cyprus Shoshone Mines uses the longwall method to extract a deep, thick, pitching coal seam in the Hanna Basin of South Central Wyoming. The immediate, and main roof rock consists of weak, thinly-bedded, silty mudstones with weak, interbedded fine-to medium-grained sandstone. Tailgate ground control has been a critical factor impacting productivity at the mine. A gateroad condition mapping program for the 11 left longwall gateroads indicated potentially severe ground control problems for the tailgate. It was predicted that the existing, secondary support pattern of wood cribs would not provide adequate support capacity. Longwall coordinators and engineers made the decision to use a low density, pumpable cement known to the industry as Tekseal{trademark}, to provide the system required. A 200 psi ultimate strength mix was decided on to provide the required load capacity. The existing cribs were formed with 1-in. by 6-in. boards and brattice cloth to provide the containment. To overcome the access limitations, three boreholes were drilled from the surface to the tailgate on 2,000-ft centers. A mobile pumping station was established on the surface and the Tekseal{trademark} was pumped 900-ft. down the boreholes through a 1.5-in. steep pipe, then as much as 1,800-ft. along the tailgate entry through 1.25-in. miner spray hose. The materials required for the Tekseal{trademark} supports could all be carried into the construction locations by hand. As a direct result of incorporating relatively new methods of pumping high yield, low density, cementitious grout, the Shoshone Mine reduced downtime due to tailgate ground control problems by approximately 70% in comparison with previous longwall panels. The longwall set three monthly production records while mining the 11 left longwall under the deepest cover, steepest pitch, and most extreme ground control conditions ever encountered at the mine.
- OSTI ID:
- 124665
- Report Number(s):
- CONF-950811-; ISBN 0-930284-56-9; TRN: IM9548%%255
- Resource Relation:
- Conference: 14. conference on ground control in mining, Morgantown, WV (United States), 1-3 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of 14. International conference on ground control in mining: Proceedings; Peng, S.S. [ed.] [Univ. of West Virginia, Morgantown, WV (United States). Dept. of Mining Engineering]; PB: 330 p.
- Country of Publication:
- United States
- Language:
- English
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