Pulacayo Project Feasibility Study - Apogee Silver

Pulacayo 1 000 t/d Phase I Feasibility Study - NI 43-101 Technical Report
090644-3-0000-20-IFI-100
block size for the model is 5 m x 3 m x 3 m (X, Y, Z); with one unit of sub-blocking to a
minimum block size of
Table 14.3: Summary of Pulacayo Deposit Block Model Parameters
Type Y (Northing m) X (Easting m) Z (Elevation m)
Minimum Coordinates 7,744,400 739,350 3775
Maximum Coordinates 7,745,150 741,350 4,501
User Block Size 3 5 3
Min. Block Size 1.5 2.5 1.5
Rotation 10 0 0
*UTMWGS 84 – Zone 19 South and sea level datum
2.5 m x 1.5 m x 1.5 m allowed. As discussed above in Section 14.3.3, the nominal
topographic surface as defined by a digital terrain model functions as the upper deposit
constraint.
14.3.4.9 Resource Estimation
Inverse distance squared (ID 2 ) grade interpolation was used to assign block grades within the
Pulacayo block model. As reviewed earlier, interpolation ellipsoid orientation and range
values used in the estimation reflect a combination of trends determined from the variography
and sectional interpretations of geology and grade distributions for the deposit. The trends
and ranges of the major, semi-major, and minor axes of grade interpolation ellipsoids used to
estimate silver, lead and zinc grades were described previously in report section 14.3.7.
All three metals were evaluated independently using respective assay composite data sets.
Block model grade interpolation was a multiphase process for each metal that consisted of
sequential interpolation within (1) the interpreted metal domain solids below the oxide surface
DTM, (2) the interpreted metal domain solids above the oxide surface DTM, (3) below the
topographic surface DTM within the peripheral domain solid and below the oxide surface
DTM, and (4) within the peripheral domain solid above the oxide surface DTM and below the
topographic surface DTM. Individual metal domain solids, nine for each metal for a total of
27, required multiple interpolation passes to accommodate minor orientation adjustments to
the azimuth and dip of ellipsoids. This was done to better accommodate local variations in
orientation and geometry of respective domains. The minimum number of contributing assay
composites used to estimate a block grade for all metal domains was set at 2 and the
maximum number of contributing composites was set at 9, with no more than 3 contributing
assay composites allowed from a single drill hole. Block discretization was set a 1Y x 1X x
1Z. Model blocks identified as occurring within the underground workings solid model were
removed from the resource estimate after grade interpolation was completed. Interpolated
silver, lead, and zinc block grades were used to calculate NSR block values within the
sulphide zone by means of the net smelter calculator discussed in section 14.3.3. This
calculator considers metallurgy, economics, and costs relevant to sulphide zone resources
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