Abstract: Taking the treatment of zinc-bearing dust by rotary hearth furnaces (RHF) as the a direct reduction mathematical model of carbon-containing pellets made of zinc-bearing dust was built in combination with the actual production process of RHF. The model takes into account not only the reduction of iron oxides and Boudouard reaction but also the reduction of zinc oxide. Experimental results proved the validity of the model. The effects of furnace temperature, pellet radius and porosity on the reduction of the pellets were investigated on the basis of calculation data by the model. Furnace temperature has significant effect on the metallization rate and zinc removal rate; but pellet radius and porosity have less influence on metallization rate and no influence on the zinc removal rate.