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Technical Memorandum ■■ <br /> Cripple Creek&Victor Gold Mine ■ <br /> SGVLF Stability Evaluation—Nonagglomerated Tailings <br /> NewFields Job No.475.0106.009 <br /> 1 June 2017 <br /> 3.3 Stability Results <br /> Results from the stability analyses identify the friction angle of the future leach material <br /> necessary to achieve the minimum required factor of safety, and they are summarized in Table <br /> 4. The global stability of the facility slopes were analyzed for ultimate (full buildout) conditions <br /> prior to regrading for closure. Output graphics from the stability models are included in <br /> Attachment C. <br /> TABLE 4—STABILITY RESULTS <br /> Minimum Factor <br /> Pseudostatic Type <br /> Section Slope Static/ Section Orientation Failure Friction Angle* of <br /> (degrees) Safety <br /> Static Top of Pad to PSSA Circular 28 1.3 <br /> Facility <br /> Pseudostatic Top of Pad to PSSA Circular 29 1.15 <br /> A 2.5H:1V Facility <br /> Static Top of Pad to PSSA Block 24 1.3 <br /> Facility <br /> Pseudostatic Top of Pad to PSSA Block 26 1.17 <br /> Facility <br /> Static Slope NW of Pad/ Circular 37 1.3 <br /> Slope above Mill <br /> B 1.6H:1V Slope NW of Pad/ <br /> Pseudostatic Circular 38 1.16 <br /> Slope above Mill <br /> *Friction angle was varied during parametric study in order to determine the minimum value <br /> required to achieve the minimum required factor of safety. <br /> Results indicate that, for the current fill plan of the SGVLF, the slopes are stable if the friction <br /> angle of the ore, or ore-tailings mixture, is 38 degrees or greater. Section B was identified as <br /> the most critical slope due to the reduced bench widths and overall slope angle. <br /> 3.4 Sensitivity Analysis for Non-Homogenous Heap Leach Material <br /> It is understood that the combination of nonagglomerated tailings and ore is not an accurately <br /> measured process. There is the possibility that the tailings could sometimes exceed a mass <br /> ratio of 10 percent tailings to ore; however, it is believed that this would occur infrequently. A <br /> more likely scenario that could develop would be concentrated pockets, or seams, of tailings <br /> scattered within the heap, as mixing to create a perfectly homogenous material is difficult. <br /> Based on our understanding of the mixing and depositional process, thin lenses of concentrated <br /> tailings could develop in the pad. <br /> Page 6 <br />