Full factorial design unravels critical particle size interactions governing porosity-strength balance in clay-chamotte-rice husk refractories

While the individual effects of particle size on ceramic properties are well-documented, the synergistic interactions between multiple components’ granulometry remain poorly understood. This study employs a full 2 3 factorial design to decouple and quantify these complex interactions between chamotte (CHM), clay binder (KG), and RH particle size (0 – 100 µm vs. 100 – 250 µm) particle sizes on porosity, flexural strength, and firing shrinkage. The results demonstrate that property optimization is governed by significant binary interactions where the effect of one component is contingent upon the granulometry of others. Maximum porosity (68 %) was achieved with fine particles of all components, while minimum shrinkage (0.43 %) required medium CHM with fine KG and RH. Highest strength (3.4 MPa) was obtained with the fine CHM and medium KG. Our models demonstrate, for instance, that the influence of chamotte particle size on strength reverses depending on clay binder size, challenging conventional single-component optimization approaches.