Characterization of the compositions of copper and nickel/copper mattes
Computer modeling of smelting processes requires internally consistent equations for calculating the compositions of mattes and slags. That is, the sum of the calculated assays must total 100%. One set of equations that satisfies this requirement for copper produced under oxidizing conditions (pSO2 > one atmosphere pressure) is given by the following: %[Fe] = 62.0 – 0.775%[Cu] %[S] = 28.0 0.00125%[Cu] 2 %[O] = 10.0 – 0.225%[Cu] + 0.00125 %[Cu] 2 Mattes containing nickel in appreciable quantities do not have the defined “white metal” end point of approximately 80 percent copper and 20 percent sulfur that is found in the copper system during the converting process. The above equations, however, are readily extended to nickel and nickel/copper mattes for any desired end product composition.