Effect of Plant-Derived Organic Binders on Fracture Toughness and Fatigue of Kaolin-Based Refractories

The fracture properties of kaolin-based refractories prepared using plant-derived binders from okra and “mrenda” have been investigated and compared. It was observed that the MOR of fired samples improved from 37.5 ± 0.1 MPa (for binder-free samples) to 69.6 ± 0.1 MPa, and to 120.0 ± 0.1 MPa for okra- and ‘mrenda’-plasticized samples, respectively, while the fracture toughness increased from 3.9 ± 0.1 MPa (for binder-free samples) to 5.6 ± 0.1 and 5.7 ± 0.1 MPa for okra and ‘mrenda’-plasticized samples, respectively. It is concluded that the use of organic binders enhances the reliability and service life of kaolin refractories used in thermally fluctuating environments.