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West Elk Mine <br /> <br />2.05-5 Rev. 11/04- PR11; 03/06- PR10; 07/15- MR413; 07/18- PR15, 01/24-TR152, 04/24-TR154 <br />The mine panels were and have been laid-out to recover as much coal as possible with <br />consideration for personnel and equipment safety and surface protection. The percent of <br />recovery in the development (room and pillar) sections is approximately 40-60 percent, more or <br />less, depending upon pillar design. Longwall panel extraction methods increase that extraction <br />ratio to 80-90 percent for the mining height, which is planned at approximately 10.0 to 12.0 feet <br />for the B Seam and 8.0 to 14.0 feet for the E Seam. Using retreat mining in the mains, MCC <br />plans on recovering 30 to 60 percent of the remaining coal depending on the location of the <br />pillar. <br /> <br />In 2023 mining was completed in the Sunset South Panels located in the E Seam. While mining <br />this area many adverse mining conditions were encountered including faults and partings, and <br />poor roof conditions due to the presence of mudstone bands, coal rider seams and weak <br />laminations. Furthermore, on development it was found that the seam height reduced to a non- <br />minable height on the east sides of the panels, causing all four Sunset panels to be shortened <br />from earlier projections documented in Permit Revision 15 (PR-15). <br /> <br />During longwall mining of Panels SS3 and SS4 the mudstone bands, coal rider seams and weak <br />laminations created an un-washable product resulting in the need to cease mining earlier than <br />projected in both Panels. SS3 Panel had a projection of 2.3 million tons and produced 2.0 million <br />tons. SS4 Panel had a projection of 2.2 million tons and produced 0.4 million tons. <br /> <br />PR-15 permitted 10.1 million tons to be mined from the Sunset Trail area. However, due to the <br />adverse conditions encountered mentioned above, only 6.9 million tons were recovered. To <br />maximize the amount of coal from the permitted area, Technical Revision 152 was submitted to <br />recover approximately 20,000 tons in the Sunset South Mains, Technical Revision 154 and <br />Minor Revision 484 was submitted to recover another approximate 275,000 tons in the Sunset <br />Mains, bringing the final total recovered tons from the Sunset Trail area to 7.21 million tons, <br />2.89 million less then what was originally approved. <br /> <br />The actual coal recovery will depend on the method of coal extraction as well as the actual coal <br />seam thickness. Using room and pillar methods, MCC recovered about 50 percent of coal <br />reserves in the F Seam. Using the longwall mining method, MCC has recovered and plans to <br />recover about 80 percent of the thickness mined for the coal reserves of the B and E Seams <br />(Table 29), based upon the current plans projected operations (see Maps 51 and 52.) Anticipated <br />annual production is shown with expected employment needs in Table 32, (Section 2.05.3). <br /> <br /> <br />Table 29 <br />Recovery Rates for Room and Pillar and Longwall Mining Methods <br />Room and Pillar Method <br /> <br />Location Coal Recovery <br />Main Development 30 – 40 % <br />Mains Retreat Mining 30 – 60% <br />Submain Development 30 – 40 % <br />Panel Mining <br /> Partial Pillar Extraction 45 - 55 % <br /> Full Pillar Extraction 60 - 80 % <br />Total 50 %