Evaluation of thermo mechanical and corrosion properties of uniaxially pressed refractory blocks used in the transition zone of cement rotary kilns

Abstract

Alkali resistance is of great importance for the refractories used in the transition zone of cement rotary kiln. In this present work, Andalusite were selected to replace the bauxite in refractories used for transition zone of cement rotary kiln. The effect of Andalusite is enhanced by incorporating micro silica. The originality of the work is that it brings a new platform of using Andalusite incorporated with micro silica for cement rotary kiln application. The thermo mechanical properties like Permanent Linear Change, Refractoriness Under Load, Thermal Shock Resistance, abrasion resistance and alkali resistance of the developed andalusite incorporated with micro silica refractories was compared with the existing bauxite and SiC based. The results confirm that andalusite is a better refractory material and also reveals that micro-silica incorporated andalusite refractories have excellent alkali resistance against K2CO3 / K2SO4 at 1250 °C for 24 h and also it can able to withstand a temperature of 1444 °C. Addition of micro-silica up to 1% forms glassy phase and increases the compressive strength and also improves densification than other refractories. The andalusite – micro silica composite refractories manages to survive 30 + cycles on water quenching from 950 °C. 1% addition of micro silica in andalusite shows better alkali resistance, abrasion resistance and refractoriness under load.