Transmission characteristics of a composite made with ground granulated blast furnace slag

In this paper, we propose a new composite shielding material using ground granulated blast furnace slag (GGBFS), a byproduct of iron refining. To investigate the feasibility of GGBFS inclusion in shielding material, we fabricated a composite GGBFS material and measured its electromagnetic transmission characteristics. First, we measured the permittivity and permeability of GGBFS itself using a 2-port coaxial cable system. After fabrication of the proposed composite GGBFS material, the permittivity of the proposed structure was measured using the resonance cavity method to obtain the basic electromagnetic material properties. When GGBFS is added to an epoxy resin composite material, permittivity increases by approximately 1.5. To show its feasibility as a shielding material, we fabricated planar samples and measured the electromagnetic transmission characteristics between 6 and 12 GHz using the free space measurement method. The results show that the sample's shielding level is approximately 1.5 dB in the frequency range between 6 and 12 GHz for a GGBFS content of 30% and thickness of 2 mm. We also obtained a 3 dB (50% of incident power) shielding level at 8.5 GHz for a 5mm thick sample. The new proposed material in this paper capable for use in many shielding applications and provide a new opportunity for recycling industrial waste.