2.0 Two-Product Formula Error Amplifica on Consider the generic problem of a mineral separator functioning at steady state with a solids yield Y that achieves species recoveries ranging from 0 to 1. For convenience we express all yields and recoveries as fractions between 0 and 1. We started with a set of arbitrary feed assays GF,i and species recoveries Ri for 21 species. For an assumed overall yield Y, we calculated the product and tailings grades for each species. For example, consider a separation with yield Y = 0.20 of a species with feed grade GF,i = 5 wt.%. For a species recovery Ri = 0.50, GP,i = (0.50/0.20)×(5 wt.%) = 12.5 wt.%, and therefore the tailings grade is GT,i = (5 wt.% -0.20(12.5 wt.%))/(1 -0.20) = 3.125 wt.%. These values are deemed the true values.