Yep. Mexico's a good guess. Your points in sequence: I should...

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    Yep. Mexico's a good guess. Your points in sequence:

    I should have used the term "Utilised hours", rather than available hours. Availability for gear in reasonable nick is around 85%, over its life. Utilised hours are those when its doing useful work. Once you factor in wait time, maintenance and general messing about, the number rapidly drops to around 6,400 hours. Less, once a productivity factor is included to estimate "Effective Utilised Hours" and this is highly dependent on the level of education of the workforce.

    I get suspicious of operations claiming IRR>say 40%, unless there are good reasons - pre-existing infrastructure, high grades and easy to mine ore.

    Cutbacks - nope. The whole idea is to defer capital movement of waste. At a realistic discount rate, a dollar spent on capital waste movement in (say) three years' time is worth, what, $0.67? So to maximize NPV (in todays dollars) waste movement should be deferred for as long as possible.

    I don't have a problem at all with coarse gold or even placer deposits for that matter. Or tailings dams. All JORC requires is that the confidence in estimation is clearly explained and the resultant Resource appropriately classified. That said, it is difficult to get better than Inferred for highly variable deposits. The only approach is appropriate bulk sampling or identification of a more consistent proxy element - eg As may have a lower coefficient of variance than Au in a gold deposit, but the As grades directly correlate to elevated Au grades. It's all in the data analysis.

    You have commented in the past on a (no longer ASX listed) WA developer controlled by a Melbourne based "colourful mining identity". There's actually no reason under JORC why this outfit couldn't make compliant public statements, other than the extreme reluctance (or inability) of the parties involved to clearly state confidence in the sampling and assay techniques.
 
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