This thread brings up a question that I have never been able to fully answer. What role did the "sampling works" play in all this? It is my understanding that these facilities "sampled" a particular shipment of ore to establish the mineral content (and hence the value) before being sent to the mill and smelter.
The mine producing the ore was paid on the basis of this content - less the cost of other less valuable things in the ore which would interfere with the milling process and therefore cost extra to remove.
In these cases, would it really be necessary to keep the various batches separate?
CJ