Mining in Manitoba |
Cut & Fill Mining |
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Stope Development The development of a Cut and Fill stope usually consists of the development of the following :
When preliminary exploration diamond drilling has outlined a potential cut and fill area, the development of the stope begins with driving a drift through the orebody along the footwall contact. This drift is commonly called the Sill Drift and is driven at the sill elevation of the stope, generally at base of rail.
The footwall extraction drift is developed behind the footwall ore drift at an adequate distance away from the stop.
The widening of the ore drift to the hanging wall contact is done by slashing where the orebody is less than 25' wide. In widening the stope to its full width, effort must be taken to establish a 1':7' shanty back to assist with ground control. Where the width exceeds 25', additional ground support is made by leaving a rib pillar.
The sill timbering consists of building stringers and log mat for the recovery of the crown pillar of the stope beneath, and the construction of the bases for service manways. This timbering is done after the first cut over the sill cut has been mined out.
The excavation of the boxholes in the extraction drift begins when a minimum of 2 feet of 10:1 cemented fill has been poured over the log mat. In this way, the rock excavated may be dumped in the stope as fill.
Two bored raises for ventilation are normally driven at the very beginning of the development of a cut and fill stope. The remaining raises are developed as the widening of the stope is completed. The bored raises are lined with culvert and serve as passageways for men, material, services and ventilation to or from the level above.
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