RE: spoke with the PrezHi 4u!
Different ore bodies may have different metallurgical characteristics that would render them incompatable in the same processing circuit. For example, we know that the much of the gold content from the Clearwater deposit occurs as coarse gold particles within the mineralization. Coarse gold is usually run through a primary circuit using gravity separation to recover as much of that larger grained gold as possible, since it will often not disolve into a vat leaching treatment or bond with reagents in a floatation cell. So just packing that ore up and sending it to the nearest mill will not yield optimum recovery if that mill does not have a gravity separation process.
The operating margins for most mines are dependant on gaining the highest possible efficiency from the recovery circuit. A mill is therefore tuned to achieve greatest efficiency, optimizing variables like particle size, concentration of reagents, treatment time, etc. If ore feeds from other deposits that are not compatable to those parameters are run through the mill, then the result will be poor recovery, lower revenues, and possibly a money losing operation.
cheers!
COACH247