1991-05-01_REVISION - C1991078 - Laserfiche WebLink

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2 . 05 . 4( 2) (b) In round numbers the amount of material , measured in cubic yards , that will be handled to reclaim the mine at the worst case condition is as follows: Topsoil Spoil Spoil Spoil From From From From Highwall Stockpile Stockpile Ridges Reduction Area 1 25,000 36 ,000 56 ,000 22 ,000 Area 2 75,000 20,000 58,000 89,000 Pond B 14,000 The 25 ,000 cubic yards of topsoil in Area 1 repre- sents 15.5 acres of untopsoiled area using the 12 inch topsoil replacement depth . In Mining Area 2 the topsoil replacement depth is 20 . 1 inches . The 75 ,000 cubic ,yards of topsoil in Area 2 therefore represents 27 . 8 acres of untopsoiled area. The topsoil in the Pond B area is just that topsoil salvaged during the Pond B construction which represents a disturbed area of about 3 acres . The total area to be topsoiled and reclaimed in this analysis is ( 15 .5 + 27 .8 + 3 ) 46 . 3 acres . The haul distances for the spoil and topsoil from the stockpiles and the average grade for both are as follows: • Mining Area No. 1 Mining Area No. 2 Pond B Topsoil Spoil Topsoil Spoil Topsoil Haul Distance 2400' 900, 3600' 3000' 300' Grade 2. 2% 2.9% 2.7% 2.5% -6 . 7% The following discussion forms the basis for the above reclamation estimate: Spoil and Topsoil It will be assumed that an equipment spread of two 651E scrapers and one D-9 push cat will be used to haul the spoil and topsoil . Cycle times and productions are as follows . The CY/Hour production figure assumes two scrapers , a 50 minute work hour, a payload of 34 . 6 cubic yards of topsoil and 34 . 6 cubic yards of spoil . The cost per cubic yard is calculated using an hourly rate of $150 for the D-9 and $175 for the 651E scrapers . Load/Dump Haul Return Total CY/Hour Cost/Cy Topsoil Area 1 1 . 3 1 . 6 1 .0 3 .9 444 1 . 13 Spoil Area 1 1 . 3 0.6 0 . 5 2 . 4 721 0.69 Topsoil Area 2 1 . 3 2 . 2 1 . 4 4. 9 353 1 .42 Spoil Area 2 1 . 3 1 .8 1 . 2 4 . 3 402 1 . 24 2 .05-17i July 1991