Laserfiche WebLink
Sections may be added or deleted from any part of the mine to meet production requirements so long as the <br />operational activities are within the permit boundary and the performance standards are met. The system outlined in <br />this permit represents the best engineered estimates of operation, but in no way restricts the number of sections used, <br />location of sections or production tonnage to be produced in the Permit Area. <br />Room and Pillar Minin <br />Due to uncertainties concerning marketing, economics, and availability of the longwall system, MCM reserves the <br />right to reemploy room and pillar mining at any given time and any given location of the No. 5 and No. 6 Mines. The <br />following is a general discussion of the mining methods and equipment utilized in standard room and pillar mining. <br />The room and pillar mining method employed by MCM develops mains and sub -mains on advance, and large areas or <br />panels are developed for pillaring. A list of the major equipment utilized in room and pillar mining is presented in <br />Table 54, Room and Pillar Equipment List. <br />Mining operations for each coal seam have been engineered to optimize extraction by developing entries with the <br />height and width based upon the immediate strength characteristics of the roof, floor, and coal. The pillars are then <br />designed to accommodate the readjusted load of the overburden strata. Certain areas are designed for full extraction <br />of the pillars where the roof is allowed to cave behind the pillared areas. MCM has maximized resource recovery by <br />adopting a maximum recovery rate compatible to the anticipated stress loads in accordance with prudent mining <br />practices. <br />A continuous miner and shuttle car system is used to cut and haul the coal to the belt conveyor systems. In <br />conjunction with the standard room and pillar mining system, MCM uses a pillar extraction system to optimize <br />resource recovery. During the many years of its operation, MCM has employed the use of several room and pillar <br />mining plans, including the use of three -entry, four -entry, and five -entry systems. To give a better understanding of <br />how these entry systems work, MCM has included within this permit document several figures illustrating the layout <br />and function of room and pillar mining: <br />• Figure 48, Typical Three -Entry System <br />• Figure 49, Typical Four -Entry System <br />• Figure 50, Typical Five -Entry System <br />• Figure 51, Typical Room and Pillar Mining Section <br />• Figure 52, Typical Partial Pillaring Plan <br />Contingent on mining conditions, the room and pillar method may follow the general patterns illustrated by these <br />figures. MCM will use the previously mentioned major equipment in its extraction of coal, whether it is a three -entry, <br />four -entry, or five -entry room and pillar section. This equipment is coordinated at the face to develop the number of <br />entries necessary for the specific development or mining according to several parameters determined as mining <br />occurs. These parameters include coal seam height, consistency, fault location, type of panels being driven, water <br />conditions, and overlying surface structures. <br />Room widths are generally 20 feet, but may vary depending on roof and floor conditions. Pillar size, length of rooms, <br />coal for roof support, room widths, and angles of cross cuts may vary according to the approved MSHA Roof Control <br />Plan. The anticipated sizes are determined and set forth in this section. <br />Three -entry systems are generally used to develop inside panels. Generally, mains are developed by five -entry <br />sections and remain for the duration of the mine. Occasionally, four -entry systems are used when severe roof, floor, <br />or coal conditions are encountered requiring the operator to drop one of the five entries. However, this does not <br />preclude the use of four entries for panel development. <br />MSHA Roof and Ventilation Plans <br />In accordance with MS14A regulations, roof and ventilation plans must be submitted for approval prior to mining. <br />TR14-36 2.05-6 Revised 03/10/14 <br />