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<br />• Haul the Overburden Material to the Backfill Area <br />• Clean the Coal <br />• Prepa re a Drilling Bench on the Interburden <br />• Drill the Blastholes <br />• Load the Blastholes With Explosives <br />• Blast the Overburden <br />This same sequence is used for each bench as each coal seam is <br />removed. <br />The number of blastholes which are detonated per 8 milisecond delay <br />period is determined utilizing the weights and distances table <br />within the Rules and Regulations and shown on Table 2.05=6, Blasting <br />Parameters. Typically each drill hole contains approximately 65 <br />lbs of AN FO blasting agent. Normally a pattern of 10' x 10' is <br />• utilized and where possible each row is delayed from the next row. <br />Normally 25 milisecond delays are utilized between each row. <br />However, where the weights and distances tables does not allow <br />detonating this much powder or explosives within an 8 milisecond <br />period, Table 2.05-6, Blasting Perameters, Overburden is utilized <br />in lieu of the typical blasting pattern. Figure 2.05-2, Typical <br />Blasthole Loading Diagram, shows the amount of stemming material <br />and the planned sequence of placing the explosives, primers and <br />down line into the blasthole. Normally, the powder factor of <br />approximately .6 lbs. per cu. yd. is utilized to fragment the <br />overburden and Interburden. <br />GEC Minerals, Inc. utilizes a system of warning and all clear <br />signals within the permit area to ensure that all personnel are at <br />a safe distance away from the blast area. The warning signal is a <br />series of three short blasts on a horn approximately 5 minutes <br />prior to detonating the blast. In addition, the personnel at the <br />• Dorchester Colomine Coal Mine adjacent to GEC Minerals, Inc. are <br />2.05-17 <br />