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
Mercator core check sample results are compared to original Apogee results in Figure 12.38,
Figure 12.39 and Figure 12.40 for Ag, Pb and Zn respectively. A correlation coefficient of
0.78 applies to the Ag data set but removal of one sample having an original value of 529 g/t
and a check result of 21 g/t moves the correlation coefficient to 0.98. Pb results show good
agreement between data sets, with a correlation coefficient of 0.96, while Zn data show
higher variability between samples that is reflected in a correlation coefficient of 0.83.
Results of the Mercator check sample program are interpreted as showing that reasonable
correlation exists between the original and check sample data sets in all but one instance of
an anomalous Ag result. The value in question may suggest spatial heterogeneity of Ag
within the sample interval but could also be a result of sample contamination or analytical
error. Despite the lower correlation coefficient for Zn results, all original samples that returned
a grade of greater than 2.00% also returned a check value greater than 2.00% and samples
below that threshold provide a correlation coefficient of 0.99. These results confirm the
anomalous character of mineralization within the sections sampled, particularly at grades
below 2.00%, and indicate that lower correlation at higher grades may be related to
heterogeneity of sulphide mineral distribution at the core sample scale rather than analytical
error or sample contamination.
Figure 12.41, Figure 12.42, and Figure 12.43 show good correlation between original sample
values and the check sample values for coarse reject materials submitted by Mercator and
support correlation coefficients of 0.99 for all three metals. Blank sample results for the
Mercator sample suite returned values below detection limits for all three metals and results
for certified reference material CDN-SE-1 all fall within the mean ±2 standard deviations
control limits for the material. CDN-SE-1 returned grades of 714.83 g/t Ag, 1.83% Pb, and
2.67% Zn.
Mercator considers results of the August 2011 independent QAQC program to be acceptable
and to reflect consistency with the results reported by Apogee.
Figure 12.38: Mercator ¼ Core Check Samples - Ag G/T (N=9)
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