Abstract

The reduction of iron oxides from liquid slags is important in the nonferrous as well as the ferrous industry. In the primary smelting of copper, the trend is to produce copper mattes with increasing contents of copper. This is accomplished by increasing the degree of oxidation, leading to more oxidized slags with higher copper contents. To recover this copper, the high magnetite content of these slags has to be reduced in a separate slag cleaning process. Laboratory reduction experiments on commercial copper slags using carbon monoxide-containing gases show that the reduction rate increases with increasing injection depth and slag temperature. The reduction rate was found to follow the relationship Rate (mol O /m 2 · s) = 7.9 · 10 5 · e-43,300/t(K) ·pco (Pa) with an activation energy of 360 ±20 kJ/mol.