Wednesday, February 6, 2013

More CUU Details

As seen in the NRs, the bottom gets better. In my last post I showed why.

Initially, the most plausible cut-offs for appropriate grade shells were thought to be 
0.20 CuEq% for Paramount and 0.25 CuEq% for Liard.  If a 0.20 CuEq% cut-off was chosen for Liard, the deposit would have been overly extended with vague 
boundaries only driven by the existence of data.  This suggests that the bottom of the deposit has not been defined by drilling, and that the mineralization is still open at depth.  Additionally, the 0.25 CuEq% cut-off grade shells have plausible envelopes that may relate to the alteration and mineralization patterns.  For these reasons, cutoff grade shells of 0.25 CuEq% were used in the resource estimation.

A top-cut or “cap” of 1.8% was chosen for copper.  Out of 25,398 samples with assays, 39 are greater than 1.8% copper, or 0.122% of the sample population. Figure 14.11 depicts the characteristics of the total copper grade distribution within the Paramount and Liard Zones combined.  Note the lognormal deviation of the highgrade samples around the 1.8% copper position.

It's worth noting the new data vs the old samplings. See figure 14.11 in the document.

Ore is stockpiled during the pre-stripping activity in the pre-production period and the first six years of production.  The majority of the pre-production stockpile is fed to the mill in Year 1.  The mid- and low-grade stockpiles continue to grow peeking in Year 9 at 140 Mt. A significant portion of this ore stockpile is then used as mill feed in years 10 to 12 while stripping down to ore in Phase 3N.  The ore stockpile is also used as a source of mill feed in Years 15 and 16 while stripping the final Phase 4N to ore. series of small accelerations in Phase 4N will reduce the need to use the stockpile but has not been designed into the schedule at this time.

Perhaps some more to come. As you can see, there are a number of details not reported in the NR. Instead, they gave broad ideas of the improvements to come.

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