In this metallurgical (material/MatBal balance) involving 2 concentrates or 3 products, we have this example:
It is decided to take a copper tail (zinc feed) sample in order to provide a check on the results calculated in the previous example. The sample (CT) assayed 0.55% Cu (c5) and 20.9% Zn (z5), respectively. The check weights of the copper and zinc concentrates are computed as follows:
As can be seen, the calculated weights of the copper concentrate check exactly, while the zinc concentrate checks within 1.3%.
An average of the zinc concentrate weights, obtained using both methods, could be used if desired.
It should be understood that there are certain limitations to the use of three-product formulas, since it is required by definition that two of the three products involved must be concentrates of essentially different metals or mineral components. The formulas will only give reliable results when the assays indicate that a differential concentration of the two components into separate concentrates has occurred.