Development of Sustainable MgO–C Refractories Using MgO–C Recyclates and a Novel Eco‐Friendly Fructose–Tannin Binder Crosslinked With Citric Acid

This study focuses on the synthesis of green refractories using recycled MgO–C refractories and sustainable binder systems as alternatives to conventional resin‐ or pitch‐based binders used in industry. The main focus was on the development of a new binder system based on fructose and tannin crosslinked with citric acid. The developed binder system was successfully used to fabricate MgO–C refractories containing up to 50 wt.% MgO–C recyclates, with a cold crushing strength of approximately 23 MPa. The influence of citric acid as an effective cross‐linker in enhancing the cold crushing strength was investigated. The thermomechanical and physical properties of the developed MgO–C refractory samples were characterized. These sustainable MgO–C materials were successfully used in steel immersion tests, surviving the harsh thermal shock conditions and showing no adverse effect on the population of nonmetallic inclusions compared to conventional MgO–C refractory material. Microstructural and inclusion analyses of the post‐immersion samples were performed using scanning electron microscopy/energy dispersive X‐ray spectroscopy and automated feature analysis, providing insight into the interactions between the refractories and molten steel.