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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 /> The tailings are made up of 92 percent coarser, flotation tailings and 8 percent finer, <br /> concentrate tailings. <br /> 2.1 Particle Size Analysis <br /> The particle size distribution of the specimens was determined in accordance with ASTM D422 <br /> procedures. The results for each sample were used to assess the percentages of gravel, sand, <br /> silt, and clay sized particles, as shown in Table 1. Both Ore 1 and Ore 2 classified as poorly <br /> graded, 3-inch minus gravel with sand and clay. Overall, minimal differences in the particle <br /> distribution were noted between the ores. Flotation tailings classified as silty sand and <br /> concentrate tailings classified as lean clay. Laboratory test result sheets are included in <br /> Attachment A. <br /> TABLE 1-PARTICLE SIZE ANALYSIS <br /> Grain Size Distribution(%Passing) <br /> Sample Type Gravel Sand Fines <br /> 3.0" 1.5" 0.75" 0.375" #4 #10 #20 #40 #50 #100 #200 <br /> Ore 1(Cresson) 100 90.7 62.4 41.7 34.3 24.0 16.7 13.0 11.4 9.2 7.7 <br /> Ore 2(WHEX) 100 99.6 76.6 41.7 33.8 22.1 16.0 13.1 11.7 9.8 8.5 <br /> Flotation 100 100 100 100 100 100 99.9 96.7 87.8 64.1 46.5 <br /> Tailings <br /> Concentrate 100 100 100 100 100 100 100 100 100 99.8 99.0 <br /> Tailings <br /> 2.2 Atterberg Limits <br /> The Atterberg limits test was used to measure the moisture content of the upper and lower <br /> limits of the range in which a soil behaves plastically. The moisture content at the upper limit is <br /> known as the liquid limit (LL) and the moisture content at the lower limit is designated the <br /> plastic limit (PL). The numerical difference between the LL and the PL, termed the plasticity <br /> index (PI), is a measure of the soil plasticity. Soils that do not exhibit cohesive behavior are <br /> termed nonplastic. Atterberg limit tests are performed only on the portion of the material that <br /> passes the No. 40 (0.42-mm) sieve. The test results indicate that the finer particles in Ore 1 <br /> have low to medium plasticity, while Ore 2 has a medium to high plasticity. The flotation <br /> tailings are nonplastic and the concentrate tailings have medium plasticity. Table 2 presents <br /> the results of the Atterberg limits tests. <br /> Page 2 <br />