Effect of Deflocculants on High Alumina Low Cement Castables

Abstract

Refractories are an integral part of iron and steel making industries, and they face challenging operational parameters at elevated temperatures. Hence, there has been a shift of focus towards unshaped refractories, over conventional and shaped refractories. Refractory castables consists of a mixture of aggregate refractory grains, matrix phases, binders, deflocculants and other additives. In order to get the optimum result as envisioned, castable manufacturing needs to be controlled right from compositional batch calculation to the firing process. In this project, the effect of different types of deflocculant and its amount on high alumina low cement castables is observed. As the flowability is dependent on the particle size distribution and packing of the castable system, the particle size ranges follow a continuous distribution approach based on Dinger-Funk equation. The work studies for a distribution coefficient of q=0.21, which lies in the self-flowable castable zone. To determine the physical and mechanical properties, castable sample blocks are casted in a pre-fixed mold and subsequently dried and fired at two different temperatures namely, 900 °C and 1500 °C. The dimensional measurement and Cold Crushing Strength was observed at each step. Thus, the Bulk Density, CCS, Flowability values and XRD of different batches were analysed and discussed. The varying effect of different deflocculants were noted.