GOODY MORNING MY Friend Suds: Excellent post, I would like to add that each days, sometimes hours, production requires a different handling process, I.E. tweaking.
Basically, generally, there is no great change on a 'large' ore body, and one could keep going on forever with the original setup, BUT, stockholders prefer max return for their investmet, so a few more grams / ounces daily is more than welcome and worth the continual reassessment of the process.
It is not like baking a cake using the same grade flour and amount each time.
Be seeing you at the Escondida ?
Don Jose de La Mancha