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1991 Production and Geologic Oonditions <br />• Cyprus Orchard Valley Opal Corporation (OOVCC) prvduoed approximately 875,000 <br />tons of coal fr®n the Orchard Valley West Mime in 1991 under Federal Goal Lease <br />No. C-37210. Production was sustained thnxx~out the twelve months oohrising <br />calendar year 1991. <br />Mining at the Orchard Valley West Mine during 1991 entailed both panel advance <br />development and pillar retreat extraction. Panel A development was underway in <br />January, 1991. Advance development in this panel was ca~leted by mid-April. <br />Pillar retreat mining of Panel A continued thrtxx~out the remainder of the year <br />and was completed in December. The first four crtuscuts of Panel B were <br />developed on advance by January 1, 1992. Advance development of the II West <br />SU1Bnains to the west of the South III SZ~tanains was initiated in June, 1991 and <br />had progressed throtx~ crosscut 11 by the end of the year. <br />Panel A: <br />Mined IPrgth: Approximately 2900 feet of panel advance development followed by <br />approximately 3500 feet of pillar extraction upon retreat frwn the <br />section. <br />Overburden Thickness: Varying fran 800 to 1000 feet. <br />Mining Height: 9-11 feet on advance; 15-18 feet on retreat. <br />• Roof: Comprised of mudstones tendi.rg to air slack. Top opal of 2-3 feet in <br />thickness was left on the roof to prevent problems associated with this <br />strata type. <br />Ribs: Rib sloughage was minimal with ribs standing very well. <br />Floor: The lacer "D" seam was used as floor which provided oon~etent conditions. <br />Anomalous Conditions: Small seeps from both roof and floor sources were <br />encountered on development and resulted in muddy areas <br />and temporary pools of starrling water. <br />Panel B: <br />Mined ar~rfh; 530 feet of panel advance development. <br />Overburden Thickness: Approximately 750 feet. <br />Mining Height: 9-11 feet. <br />Roof: Comprised of mudstones tending to air slack. Top coal of 2-3 feet in <br />thickness was left on the roof to prevent problems associated with this <br />strata type. <br />Ribs: Rib sloughage was minimal with ribs standing very well. <br />Floor: The lacer "D" seam was used as floor which provided competent conditions. <br />1 <br />