An effective process for recycling lead from hazardous waste cathode ray tubes(CRTs) funnel glass through traditional lead smelting has been presented previously. The viscous behavior of the molten high lead slag, which is affected by the addition of funnel glass, plays a critical role in determining the production efficiency. Therefore, the viscosities of the CaO–SiO_2–“FeO”–12wt%ZnO–3wt%Al_2O_3 slags were measured in the current study using the rotating spindle method. The slag viscosity decreases as the CaO/SiO_2 mass ratio is increased from 0.8 to 1.2 and also as the FeO content is increased from 8wt% to 20wt%. The breaking temperature of the slag is lowered substantially by the addition of FeO, whereas the influence of the CaO/SiO_2 mass ratio on the breaking temperature is complex. The structural analysis of quenched slags using Fourier transform infrared(FTIR) spectroscopy and Raman spectroscopy reveals that the silicate network structure is depolymerized with increasing CaO/SiO_2 mass ratio or increasing FeO content. The [FeO_6]-octahedra in the slag melt increase as the CaO/SiO_2 mass ratio or the FeO content increases. This increase can further decrease the degree of polymerization(DOP) of the slag. Furthermore, the activation energy for viscous flow decreases both with increasing CaO/SiO_2 mass ratio and increasing FeO content. An effective process for recycling lead from hazardous cathode ray tubes (CRTs) funnel glass through traditional lead smelting has been previously. The viscous behavior of the molten high lead slag, which is affected by the addition of funnel glass, plays a critical role The viscosities of the CaO-SiO 2 - “FeO” - 12 wt% ZnO-3 wt% Al 2 O 3 slags were measured in the current study using the rotating spindle method. The slag viscosity decreases as the CaO / SiO 2 mass ratio is increased from 0.8 to 1.2 and also as the FeO content is increased from 8 wt% to 20 wt%. The breaking temperature of the slag is decreased by the addition of FeO, but the influence of the CaO / SiO 2 mass ratio on the breaking temperature is complex. The structural analysis of quenched slags using Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy reveals that the silicate network structure is depolymerized with increasi The CaO / SiO 2 mass ratio or increasing FeO content. The [FeO_6] -octahedra in the slag melt increase as the CaO / SiO_2 mass ratio or the FeO content increases. This increase can further decrease the degree of polymerization (DOP) of the slag The activation energy for viscous flow decreases both with increasing CaO / SiO 2 mass ratio and increasing FeO content.