NI 43-101 Technical report, Surface diamond drilling ... - Iamgold

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16.2.2 OREAS 101a results and interpretation
The Oreas 101a was used to verified the REE low grade values accuracy. It is a certified
standard provide by an external laboratory. It average value, 3,394 ppm TREE, is
detailed in Table 8. During 2012, the Oreas 101a was systematically sent at the
beginning of each batch (each hole) to test the instruments calibration and after inserted
randomly with the others standard to validate the accuracy of the analysis.
The Oreas 101a returned an excellent 2012 QA / QC performance (Figure 23). Two
isolated certificate needed more supervision and interpretation. In those cases, on the
same certificate the other standard and the blank performance were evaluated. Overall,
103 Oreas 101a standards were analyzed and the percentage of outliers reported is very
low. The worst performance is coming from the yttrium element. The yttrium is
excluded of the total rare earth element contain and it was analyzed for the geochemical
knowledge of the REE zone and does not influence the resource estimation.
The 2012 average value of each element is generally under the certified average value
(Table 13) which means a probable under evaluation of the REE contain on the rare low
grading assays.
Based on the previous observations, the REE low grading samples were controlled and
their data are validated for the purpose of this 43-101 report.
16.2.3 OREAS 146 results and interpretation
The Oreas 146 was used to verify the medium grade REE values accuracy. This certified
standard is provided by an external laboratory and the average value of 13,951 ppm
TREE is detailed in Table 8. During the 2012 drilling program, the Oreas 146 was
inserted randomly with the others standard to validate the accuracy of the analysis.
The Oreas 146 returned an excellent QA / QC performance during all year long (Figure
24). No assays returned values over or under twice the standard deviation limits for the
main REE elements. Only the lutetium and the yttrium have shown outlier’s values. For
both elements, it was judge has isolated cases and not enough significant to altered the
data base quality.
Better QA / QC statistic cannot be hoped for a standard. The year average value of each
element is almost the same has the certified average value (Table 14) and the coefficient
of variation is very low. The Oreas 146 confirmed the laboratory expertise and increased
the confidence level of the data base, especially for the medium grading assays.
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