43-101 2008 Technical Report On The La Fortuna Project, Durango ...
43-101 2008 Technical Report On The La Fortuna Project, Durango ...
43-101 2008 Technical Report On The La Fortuna Project, Durango ...
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<strong>The</strong> amount of gold reported recovered from heaps 1 and 2 were 325.50 ounces and 320.62 ounces of gold<br />
respectively. This gold was sold on the market in 2006 (Babcock, 2006, Northern Front, 2006).<br />
13.3.1 2006 Metcon Residual Analysis of the Heaps<br />
Following completion of the two test heaps Metcon was contracted by Castle Gold to carry out an analysis<br />
and reporting of gold distribution by size fraction; comparing head ore samples with leached ore residues<br />
for both heaps (no head sample was collected for Heap 1). Metcon’s summary report for this work<br />
(Iasillo, 2006) can be found in Appendix A as part of the Koningen (2006) report. <strong>The</strong> results of the<br />
analysis are summarized in Tables 10 and 11.<br />
Table 10. Metcon gold-size fraction distribution of Heap 1 leached ore residue.<br />
Nominal Opening<br />
(inches)<br />
Weight Distribution<br />
(%)<br />
Heap 1 (Low Grade Ore) Leached Ore Residue<br />
Assay<br />
(g/t)<br />
Gold<br />
Distribution<br />
(%)<br />
5.0 4.5 0.39 15.0<br />
-5 +1¾ 7.0 0.28 16.8<br />
+1¾ +¾ 11.2 0.17 16.6<br />
-¾ 77.3 0.08 51.6<br />
Totals 100 100<br />
Average Grade 0.12<br />
Table 11. Metcon gold-size fraction distribution of Heap 2 head ore and leached ore residue.<br />
Nominal Opening<br />
(inches)<br />
Weight Distribution<br />
(%)<br />
Heap 2 (High Grade Ore) Head Ore Sample<br />
Assay<br />
(g/t)<br />
Gold<br />
Distribution<br />
(%)<br />
5.0 10.0 1.<strong>43</strong> 8.0<br />
-5 +1¾ 19.6 1.39 15.3<br />
+1¾ +¾ 10.2 1.73 9.9<br />
-¾ 60.2 1.98 66.8<br />
Totals 100 100<br />
Average Grade 1.78<br />
Heap 2 (High Grade Ore) Leached Ore Residue<br />
5.0 6.8 1.99 16.0<br />
-5 +1¾ 19.0 1.34 30.3<br />
+1¾ +¾ 15.4 0.91 18.7<br />
-¾ 58.8 0.53 31.0<br />
Totals 100 100<br />
Average Grade 0.84<br />
13.3.1.1 Heap 1 Analysis<br />
For Heap 1, the calculated average gold grade is 0.12 g/t Au. Combining this with the carbon stripping<br />
records yielded a calculated head grade for Heap 1 of 0.25 g/t Au and an ultimate gold recovery of 51.7%.<br />
From Heap 1’s distribution of gold by size fraction, Koningen (2006) concluded that it is reasonable to<br />
expect that if all of the +¾” material were crushed to