Sorry for my tardy response. I use to be a bond trader on Bay St. When we finally agreed to a price for a transaction, it was called putting the pin in the transaction. It meant, no more back and forth but settling on a level. Theoretically, you can continue to otpimize something until the optimal solution is found. With the flow sheet, this process will continue long after the PEA, PFS and FS....right up until the time of production. Thus, now that SGS has replicated the bench scale work at the pilot plant level, they are fine tuning or optimizing the process in an attempt to reduce cost. At some point, a decision has to be made to "put the pin in" in terms of what will be used in the PEA, that was the nature of my comment.

Quincey