1997-04-07_REVISION - M1988112 (2)

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DAILY REPORT PROJECT NAME: SAN LUIS MINE PROJECT NUMBER: 92401.00 REPORT DATE: 4/14/97 TO: DAVE HALLMAN, SRK PROJECT ENGINEER FROM: GLENN GUYER, SRK SENIOR FIELD TECHNICIAN SUBJECT: LINER REPAIR AND EQUIPMENT EXTRACTION FROM TAILINGS IMPOUNDMENT. I arrived on site at 0800 hrs. At 0845 pre-welds were done on two 40 mil HDPE trial weld sheets using a columbine wedge welder with the temperature set at 700 degrees and a nozzle temperature of 550 degrees, the speed was 4.5. The ambient temp. was 46 degrees F. and the liner temp. was 58 degrees F. The wind was breezy with some clouds but dry, the operator was Chuck McMUrry and the equipment number was 2W. The peal tests were 82, 81, 78, 88, and 91 pounds per inch with film tear bond for all tests. The requirement for peal was film tear bond only. The sheer tests were 120, 111, 123, 119 and 121 PPI with film tear bond. The specified requirements were 45 PPI. All tests passed. Two 40 mil HDPE sheets, 22~ by 125, were deployed and wedge welded. The 40 mil HDPE liner adjacent to the old VLDPE liner was temporarily ballasted in place with sand bags until such time as welding with the proper rod can be done. Water from the tailings had seeped to within six inches of the existing liner edge and the contractor use a pump to control the water and keep it from the sub-grade. (see photographs attached) At 1115 hrs. a Leister Variant was used to tack weld the 40 mil HDPE liner to the 40 mil VLDPE liner after the liners had been thoroughly cleaned and dried. The roll number of the 40 mil FIDPE liner was 551103. Factory certification was received. At 1255 an attempt to extrusion weld VLDPE to HDPE was again made using HDPE rod. The peal tests failed again with inconsistent welds and water in the welds. The VLDPE rod did not arrive until after the shift in the P.M. GLENN G SRK ie Representative DALY414.WP6