Gold Grade , Profitability, and Mine IRR It's an old adage, but grade is everything in mining especially for gold mines.
That means a much larger mill, higher mining costs per ounce, larger mining camps and lower gold recovery as recovery rate and grade are positively correlated .....and longer life for your mill.
For example, if your grade is, say 1.5 grams per ton, you must process a huge amount of ore to produce 100,000 ounces .
As mining costs per ton of ore is the same regardless of grade, 100,000 ounces at 5 g/t will net you 2.5x more profit than 200,000 ounces at 1 g/t.
HD grade is 4.6 grams per ton which is very high for an open pit whose current average grades are less than 1.5 gms per ton.
Thats why the 2022 HD FS has such high IRR and will have an extraordinary IRR when mine life is extended to 10 years in the updated FS.
In short, for gold mines , grade is everything.
FWIW