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• Rule 2: Pemiils <br />5. Remove blasted overburden with front-end loaders; <br />6. Clean top of uncovered coal seam; <br />Drill blasting pattern; <br />8. Load drill holes with explosives; <br />9. Blast coal seam; and <br />10. Remove blasted coal with front-end loaders. <br />Ammonium nitrate (ANFO) will be used as the explosive material. Each blast will consist ofa maximum <br />of 72 holes drilled to a depth of 30 to 60 feet. When all 72 holes aze drilled to 60 feet, the total amount <br />of ANFO used will be 54,720 pounds for each blast. When a1172 holes are drilled to 30 feet, the total <br />amount ofANFO used will be 27,360 pounds for each blast. On the assumption that blasting will occur <br />once per day for the 255 working days, and halfthe holes will be drilled to 60 feet and halfto 30 feet, the <br />annual usage of ANFO will be 10,465,000 pounds. <br />For each blasting sequence, a maximum of 72 holes will be drilled with a 7 7/8 inch drill bit on a 16 fee[ <br />X 18 feet pattem. Boreholes will be drilled to depths needed to compliment mining plans while also <br />complying with all state and federal blasting regulations. Generally, holes will be drilled to a depth of30 <br />to 60 feet. <br />Boreholes will be primed with 11 pound and 21 pound cast primers. ANFO will then be placed in the hole <br />to a height within 10 to 20 feet ofthe surface depending on the depth of the hole. Drill cuttings wi II be <br />placed as stemming from the top ofthe ANFO column to the surface. Stemming will generally cover the <br />top 1/3 ofthe depth of the hole. The ANFO has an approximate density of 0.90 with a weight of l9 <br />pounds per foot of loaded borehole. Therefore, the maximum ANFO used for in each hole using 60-foot <br />boreholes will be 760 pounds (19 pounds/foot x 40 feet hole. The total aznount of ANFO for each blast <br />will be 54,720 pounds (760 pounds/hole x 72 holes). When 30-foot boreholes aze used, 380 pounds of <br />ANFO (19 pounds/foot x 20 feet/hole will be used in each hole). The total amount of ANFO for each <br />blast will be 27,360 pounds (760 pounds hole x 72 holes). <br />A Nonelnon-electric initiation system will be used with delays on the surface and in-hole. Shots will be <br />fired using noiseless truckline and 209 shotgun shell primers. <br />Atypical blasting sequence of 72 holes in a 16 feet X 18 feet spacing pattem is shown on Figure 2.05.3- <br />17. The sequence will start on a comer and proceed along the length ofthe pattern. The delay along the <br />length wil I be 9 milliseconds and the inhole delay will be 600 milliseconds. As shown on Figure 2.05.3-17, <br />• the second detonation on the top row will trigger the detonation in the fast hole of the second row, the third <br />P~_~~ <br />~a~~,~oPm~-Pic+~su~r-oo~ «~ 2.05-36a (Revised 7/25/01) <br />