Low cement high alumina castables: Effect of distribution coefficients

Abstract

Refractory materials used in various areas of the iron and steel industry need to face severe challenges to meet critical operational parameters at high temperatures. Hence, the attention of refractory manufacturers has shifted towards unshaped refractories to substitute for conventional and shaped ones. Castables lead in all the areas among the different unshaped refractories. Refractory castables (which are used by casting method) are premixed combinations of refractory grain, matrix components, bonding agents, and additives. The proportions are varied accordingly to achieve the desired properties. Again flowability of the castables is very important for application (casting) purposes and their final performances. Better flow of any castable allows making a good lining and makes it possible too line an intricate shape. This flowability is dependent on the particle size distribution and packing of the castable system. But better flowing mass may indicate higher sphericity of particles, resulting lower strength, which is not acceptable for refractory application. Hence design of refractory castable system is challenging as it required opposing character of flowability with higher strengths. The present work targets to study the development of refractory castable system with particle size distribution (PSD) as per well-known Dinger Funk model for continuous distribution and study the developed properties of the castables for their flowability and various characteristics developed at different temperatures.