Laserfiche WebLink
• rock slope. Planimeter measurements were translated to tons utilizing an average rock density <br />of 160tf/cubic foot of rock. Tonnage calculations are based per section, drawn on 100 foot <br />intervals throughout the ore deposit. Certain areas as described in this mine plan are highwall <br />contacts with a gypsum veneer left from past mining operations, at a time when screening of the <br />ore was not possible and a small amount of gypsum was left on all waste contacts to minimize <br />contamination of the ore muckpile. The weathered veneer rock must be removed by hand <br />barring, placement of explosives, and crane work where accessible. A rock bean area will be <br />left at the base of the Gold Hill Highwall to contain any materials which become dislodged from <br />the 55 degree sloping rock contact. Each area of the mine has been analyzed for volume <br />removal beginning at the footwall contact, the oldest section of rock along the west boundary of <br />the affected land and working east towards the hangingwall contact, the youngest rock section <br />within the affected land boundaries. <br />COST ESTIMATE ASSUMPTIONS <br />Drilling and blasting cost estimates are based on current D8B costs adjusted for positive factors <br />such as the use of the production drill currently on site and a lower powder factor necessary and <br />adjusted to negative factors such as the low efficiency of blasting the wedge shaped volumes <br />along highwall contacts and difficulty commonly experienced drilling along the edge of a <br />weathered and fractured rock face. A cost estimate of $1.00/ ton drilled and blasted was used. . <br />Bulldozer cost estimates were based on hiring an outside contractor to bring in a D-9 dozer for <br />the finish work and hangingwall push where possible. A bulldozer cost estimate of $0.50/ ton <br />was used. Other reclamation costs such as veneer removal, revegetation maintenance, seed <br />and mulch costs, road removal and fines haulage was based on experience of many years of <br />• reclamation work at this site. These cost estimations should be appropriate and valid for this <br />location for the next five to ten years from present. <br /> <br />