My Bad
On rates of grade dilution, if you have a mine that grades 14g/t and the production rate is 10.25 g/t, then the dilution of the grade is a 27% grade dilution.
If you have grades of 18g/t and your mine grades 10.25g/t, then you have a 43% grade dilution.
So the grade dilutions at Roy Lloyd vary widely from 27% to 43%.
Komis would have been ~43% grade dilution and shut down due to the crash in gold prices below cost. The grade has been adjusted to match historical production rates.
During the 1980's a mine would get shut down if grade dilution exceeded 15% and only the 'ore shoots' were mined, leaving the rest. This is why the Snip Mine has a cut-off grade of 12g/t, and why GBN.V has cut-off grades of 5g/t.
-F6