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RULE 2 PERMITS <br />Overburden and Coal <br />The complete description of the removal, handling and storage of all overburden material within the <br />permit area is described under the Production, Methods and Equipment Section found at the beginning of <br />Section 2.05.3. The mining sequence for the planned operation is shown on the Mine Plan Map (Map 23). <br />Cross sections showing the mining operation during the "steady-state" operation are found on the Mining <br />Range Diagram Map 24. <br />The planned coal production at the Colowyo operation is shown in Table 2.05-2, Historic Coal Shipped <br />(sold) Rates and Anticipated Coal Shipped (sold) Rates. <br />Blasting <br />Colowyo usually engages in blasting of overburden and coal before its removal. A general sequence for <br />drilling and blasting of overburden and coal will proceed as follows: <br />(1) Establish a drill bench on the overburden. <br />(2) Utilize the timing model to determine the maximum number of blast holes that will ignite in <br />any 8 -millisecond period, this will determine the size of the blast pattern and the maximum <br />amount of explosive to ignite at any 8 ms time period. <br />(3) Compare this poundage of explosives to the "scale distance formula" result. If the blast design <br />exceeds the criterion of the "scale distance formula," then we will revise the design until <br />compliance is met. <br />(4) Blast pattern design will then be sent to the field for implementation by the blasters. <br />(5) Drill blasting pattern. <br />(6) Load drill holes with explosives. <br />(7) Blast reports will then be recorded to meet the criteria noted in Rule 4.08.5 (1) thru (18) for <br />surface coal mining operations. <br />(8) Blast overburden. <br />(9) Remove blasted overburden with shovel, front-end loader, or dragline. <br />(10) Clean coal seam. <br />(11) Drill blasting pattern. <br />(12) Load drill holes with explosives. <br />(13) Blast Coal Seam <br />(14) Remove blasted coal with front-end loaders. <br />Colowyo will comply with all applicable state and federal laws in its use of explosives. Experienced, <br />trained, certified and competent persons conduct all blasting operations. <br />Because of the inherent complexities of the Colowyo mining operation, the surface blasting program has <br />been developed to conform with a variety of coal seams and the diverse overburden handling techniques. <br />The coal blasting will vary from coal seam to coal seam because of the different thickness encountered. <br />Three general types of overburden blasting will be required: one for blasting overburden, one for the pre - <br />splitting of overburden to provide for safer highwalls and one for blasting coal. <br />Approximate blasting patterns for coal and overburden are shown in Table 2.05-4, Blasting Parameters — <br />Overburden (Typical); Table 2.05-5 Blasting parameters — Overburden pre -Split Shot (Typical) and Table <br />2.05-6, Blasting Parameters — Coal (Typical). <br />Colowyo will conduct a timing analysis through various methods for each overburden shot utilizing the <br />down hole delay timing, hole -to -hole delay timing, and row to row timing as applicable to verify the <br />maximum number of holes and thereby pounds of explosive detonated per 8 ms time period. This <br />Rule 2 Permits 2.05-12 Revision Date: 1/31/18 <br />Revision No.: TR -119 <br />