Oxides of silicon, aluminium and calcium are normally dominant minerals during municipal solid waste (MSW) combustion. In flue gas, SiO2, Al2O3 and CaO all act as sorbents capturing heavy metals (and semi-volatile organics). To further understand the effect of sorbents during MSW combustion, the effects of SiO2, Al2O3 and CaO on Cu partitioning were experimentally investigated by the combustion of synthetic MSW in a tubular furnace and their effects on Cu speciation were studied by thermodynamic equilibrium calculations using ChemKin software. The experiments show that CaO has the highest Cu sorption efficiency at 900 degrees C, followed by Al2O3 and SiO2. Thermodynamic equilibrium calculations show that for Cu the addition of SiO2 and Al2O3 reduces the amount of liquid CuCl, which is more volatile. However, the addition of CaO has little influence on chemical sorption of Cu, indicating that the sorption of CaO is resulted from physical sorption. (C) 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.