LAUSR

Based on the ion and molecule coexistence theory, the calculation model of action concentration for system of CaO–FeO–Fe2O3–SiO2 copper slags was built up in this article. Effects of CaO, reaction temperature and reduction ratio on reduction of copper slag were discussed. Thermogravimetric experiments of the reduction of copper slag were carried out. As a good potential reductant, biomass was injected and it undertook the task of the reduction of copper slag. The contents of FeO and Fe2O3 reflect reduction degree in copper slag. The addition of CaO could change the balance of reaction system and promote the separation of Fe and Si from 2FeO·SiO2, which was in favor of copper slag reduction. The effects of temperature on mass action concentration were affected by the addition of CaO. High temperature was in favor of the reduction of Fe3O4 in copper slag. However, excessive addition of CaO (when the content of CaO was over 28% in calculate conditions) caused excessive insoluble solid in slag, increased the viscosity of copper slag and restricted reduction reactions. The calculation results achieved high conformity with thermogravimetric experiments. The results obtained in this work indicated that biomass would be a good potential reductant for reduction of copper slag. CaO had promotion effects on the reduction reaction. With the increase of CaO, reduction ratio of copper slag increased firstly and reached a peak when CaO/Slag was 0.3:1 and then it declined due to the changes of slag viscosity.