Laserfiche WebLink
411 01) <br /> Mark Loye Crystal Hill Mining Company <br /> Dept. of Natural Resources 13100 County Road 42-K <br /> Mined Land Reclamation Division Del Norte, Colorado 81132 <br /> 423 Centennial Building RECEIVED <br /> 1313 Sherman St. <br /> Denver, Coto. 80203 AUG 1 6 1986 August 14, 1985 <br /> Re: Mine Permit #81-282 <br /> MINED LAND <br /> Dear Mark: RECLAMATION DIVISION <br /> Pursuant to regulations applying to mine permit #81-282, we <br /> hereby request a technical revision to our permit so that we can steepen <br /> our ultimate pit highwall. <br /> In April, 1985 Crystal Hill Mining Company began to re-evaluate <br /> it's 53' open pit highwall angle. The developing pit gave us exact <br /> stability information by exposing the various rock zones and contacts. <br /> Our first step was to contact John F. Abel Jr. who is an aquatance <br /> of our joint venture partner, Draco Mines Inc.. John came to the mine <br /> for a tour in mid-April and wrote the attached letter of recommendations <br /> to our partners. The letter includes references to Richard D. Call who <br /> wrote the original "Crystal Hill Pit Wall and Waste Dump Stability" <br /> report that was submitted with the original permit application. <br /> Crystal Hill Mine has yet to make a decision on laying the existing <br /> highwall back this winter. The enclosed report that Abel completed in <br /> July lends itself to highwall steepening in certain pit areas. Page <br /> 6 of the Abel report divides the pit into 6 sectors of stability. <br /> Table 23 summarizes the safe highwall angles. <br /> Crystal Hill Mine has grpuped these sectors into 3 mineable <br /> sectors as shown on the attached sheet. Mining sector #1 would be mined <br /> at a 60.1° overall slope angle or a 75° bench face angle if the <br /> overall slope height is.i60 ft.. Mining sector #2 would be mined at <br /> a 53.7°overall slope angle which is equal to the existing pit highwall. <br /> Mining sector #3 would be mined at a 64.5° overall slope. <br /> We hope you will approve this technical revision and present it <br /> to the board in the September meeting. <br /> If you have any questions, please contact me. <br /> S, flcerel <br /> i <br /> Daniel D. Ki <br /> Mining Engineer <br />