2013-02-02 — mining.com
``Ore grades have tumbled from an average of 12 grams per tonne in 1950 to roughly 3 grams in Australia, Canada and the US. In some cases, cutoff grades have dipped to 1 gram per tonne. "The next cutoff," claimed Lassonde, "is dirt." Add skyrocketing production costs to the mix, and the picture becomes even more grim.''
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