From steel waste to energy storage: kish graphite derived graphene electrodes for high performance supercapacitors

Abstract

Graphite is a critical mineral, and its recovery from blast furnace dust is essential for sustainable resource utilization. Extracting graphite from industrial waste reduces the dependence on mining natural graphite, thus minimizing the environmental impact and meeting the rising demand for energy storage and advanced materials. This study extracts kish graphite (KG) from blast furnace area dust particles (BFADP) using a simple and cost-effective purification process involving magnetic separation, magnetic stirring, decantation, and acid leaching, achieving 96% carbon recovery-a significant improvement over conventional methods. X-ray diffractometer analysis confirmed an interplanar spacing of 0.34 nm at 2θ = 26.2°, resembling natural graphite, while Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) results validated a highly ordered hexagonal crystal structure. Furthermore, reduced graphene oxide (rGO) was synthesized from purified KG and then chemically activated with KOH at high temperatures to enhance its specific surface area (SSA). The electrochemical performance of KG-derived graphene was evaluated in electric double-layer capacitors (EDLCs), demonstrating excellent properties, making it a promising supercapacitor electrode material. This study highlights the effectiveness of KG purification and its potential in energy storage, offering a sustainable solution for repurposing industrial byproducts.