METHOD OF PRESERVATION OF EXTRACTION DRIFT Russian patent published in 1997 - IPC

FIELD: mining industry; applicable in preservation of extraction drift at the boundary with worked-out space for repeated use in pillarless mining of coal seams. SUBSTANCE: method of preservation of extraction drift includes installation of rigid separately standing props. Prepared in front of face at a distance exceeding the size of zone of support pressure over coal seam are niches along the strike and rise of the seam in plan sizing 3 and 1.5 m, respectively. Concrete blocks or cast-in-situ props of cementing mixtures are arranged in niches. In the spaces between props in 5-6 m before the face, coal is extracted to form coal chute and additional exit from the face appears. In extraction of marginal part of seam, props become engaged with supported rocks directly after their exposure. In this moment, roof rocks undergo minimum deformation, and the working is in stable state. EFFECT: higher efficiency. 1 dwg