Ceramics-Silikáty 54 (3) 284-289 (2010)

IMPACT OF DISPERSANTS ON THE MECHANICAL STRENGTH DEVELOPMENT OF ALUMINA-SPINEL SELF-FLOWING REFRACTORY CASTABLES

S. Otroj , M. R. Nilforushan , A. Daghighi , R. Marzban

The effect of four commercial dispersants on the properties of alumina-spinel self-flowing refractory castables was investigated. The self-flow value, water demand, physical and mechanical properties as well as microstructure of these castables were evaluated. The results showed that the polycarboxylate ether is the most effective dispersant in increasing self-flowability because of its electrosteric dispersion mechanism. By the use of proper amounts of polycarboxylate ether and sodium hexametaphosphate, the alumina-spinel self-flowing refractory castables with high strength and adequate working time were obtained. The microstructural evaluations showed that the CA₆ was formed inside the grain boundaries of refractory castable after firing at 1500°C.

Keywords: Dispersant, Mechanical strength, Alumina-spinel, Self- flow, Castable