Influence of lithium carbonate and superplasticizer as admixtures on low calcium dialuminate cement castable submitted to thermal shock

Abstract

The purpose of this study was to investigate the hot properties of low calcium dialuminate cement castable as binder with varying amount of Li 2 CO 3 and castament FS20 superplasticizer as admixtures. Thermal damage test was carried out through quenching in air for five cycles ΔT = 1175°C. The samples were preheated at 1500°C for 2 h. The results gave a retained Young's modulus of low-cement castable with 0.3 wt.% Li 2 CO 3 and 0.5 wt.% castament down to 10.36% while 0.1 wt.% Li 2 CO 3 and 0.5 wt.% castament showed a retained modulus down to 13.47%. For the samples without admixture, the loss of Young modulus was 92.4% and 93.7% with 0.3 wt.% of Li 2 CO 3 admixture. The superplasticizer has a great effect on thermal shock resistance of low calcium dialuminate cement castable. The results confirmed that 0.1 wt%Li 2 CO 3 and 0.5 wt% castament have better thermal shock resistance and longer service life for applications in refractories. The increase of mass of the refractory materials during five thermal shock cycles in air is the main factor affecting the degradation of this refractory material due to the oxidation of SiC to SiO 2 .