774 Potential resources: Blocks defined within an area containing drillholes identified in the database as waste rock were considered. In the research study carried out for the Gelado tailings dam, the measured resources amounted to 227.04 Mt, the indicated resources to 12.46 Mt, and the inferred resources to 26.66 Mt, totaling 266.17 Mt. The potential resource totals 21.25 Mt (Table 3). Table 3 – Inventory of resources estimated in this study Resource class Density (t/m3) Volume (Mm3) Ore mas (Mt) 1 2,5 90,82 227,04 2 2,5 4,98 12,46 3 2,5 10,67 26,66 1+2+3 266,17 Potential 2,5 8,37 21,25 Total 2 287,14 2.8 Methodology for tailings mining at the Gelado tailings dam Currently, tailings mining at the Gelado dam is being carried out through dredging with four electric dredges, whose specifications are described below: cutter-suction dredges; total length of 46.92 m; length between perpendiculars of 37 m; width of 8.86 m; maximum dredging depth: 16 m; maximum pumping distance: 5,970 m (5,000 m + 970 m); production rate of 750 t/h. In the mining plan, the 190 m elevation was defined as the pit bottom, considering operational constraints related to the minimum working pad width and the reach of the dredges’ booms. The parameters used for pit operation were: 5 m bench height; 20 m minimum berm width; 45 m minimum working pad width; 75° bench face angle; and 14° overall slope angle (Figure 9). Figure 9 – Topography of the pit used in the operational mine plan It is important to note that the upper elevation for the start of pit operations is 220 m, and the pit bottom elevation is 190 m.
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