Abstract: A novel method of feed preparation for silicothermic process was proposed to overcome the shortages in Pidgeon process. In this method， dolomite， ferrosilicon， fluorite and binder are mixed to produce pellets and then calcined. Thereafter， the pre-prepared pellets are charged into the retorts immediately. Heat transfer of the pellets was investigated by the steady-state-flat method and numerical method. The results show that thermal conductivity of the pellets increases with the increasing temperature， conversely with the pellet density and the amount of Si-Fe addition. For the sample pellet with the density of 1.1g/cm³ and the theoretical amount of Si-Fe， the relationship between thermal conductivity and temperature can be expressed as λ=1.04×10^-4T+0.11. Heat transfer of a spherical pellet is better than a cylindrical one. The better heat transfer from pellet surface to pellet center can be obtained for a pellet with less density， less specific heat capacity and larger thermal conductivity. The mode/mechanism/principle of heat transfer of the pre-prepared pellets is similar to the pellets used in Pidgeon process.

Key words: thermal conductivity, steady-state-flat method, pre-prepared pellets, Pidgeon process, magnesium production