PILLAR RECOVERY USING MOBILE ROOF SUPPORTS

摘要

RoxCoaL, Ine. is a Pennsylvania based underground coal mining company with four operating mines in Somerset County. Total annual output is approximately 1.5 m tosis, all being mined by continuous miners operating in the room and pillar technique. Since 1991 the company has been using mobile roof supports (MRS) for retreat mining (pillaring) in a bid to improve productivity and safety, reduce costs and increase percentage extraction during this phase of the operation. MRS are basically self contained longwall shields on cat-tracks, operated by radio remote control and used sequentially to replace timber whilst retreat mining. RoxCoal's NRS are manufactured by JH Flctcher & Co. of Huntingdon, West Virginia. This is the first application of MRS in Pennsylvania and it is believed that their application in conjunction with continuous face haulage is the first in the world. The units have been successfully deployed in a number of mining panels with extracted seam heights ranging from 44 inches to 7 1/2 feet. Safety has been demonstrably improved and productivity rates have approached those of the best longwall installations. RoxCoal believes these units provide a possible low capital cost alternative to longwalls in today's competitive environment. The paper will demonstrate the philosophy behind this modus operandi, describe the mining operations, give a technical description of the equipment and will detail productivity and cost advantages gained from the application of this emerging technology.