Valorization of Mining Waste As an Additive for Electromagnetic Shielding Application of Polymer Composites

In this study, the aim was to evaluate mining waste obtained from gold-copper plants as a functional filler material in conductive polyaniline (PANI)-based polymer composites for electromagnetic interference (EMI) shielding. Within this scope, the mining waste was added to the PANI matrix at ratios of 10-40 wt% using a melt blending method to produce composites. The mineralogical structure of the waste was determined by X-ray diffraction (XRD) analysis, the mechanical properties were examined by tensile and hardness tests, and the morphological structure was evaluated by scanning electron microscopy (SEM). The EMI shielding performance was measured in the Ku-band frequency range using a vector network analyzer (VNA). Experimental findings showed that the addition of waste significantly affected the mechanical behaviour, microstructure, and electromagnetic shielding performance of the composites. A marked increase in shielding effectiveness was observed with increasing waste content, and the results obtained revealed that waste-derived iron-containing components, together with the conductive PANI matrix, contribute to the absorption of electromagnetic waves. The results indicated that SEₜₒₜₐₗ values increased with higher filler loading, reaching a maximum of 8.4 dB for the composite containing 40 wt% waste. This study demonstrates that mining wastes can be considered a potential source for the development of high-added-value functional polymer composites.