Elaboration of a high mechanical performance refractory from halloysite and recycled alumina

The present study is a contribution to the valorization of halloysite clay from North Eastern Rif (Nador, Morocco) in the field of Silica-alumina refractory. For this purpose, six mixtures (M1–M6) were tested using marl, diatomite and silica sand aggregates in order to enhance halloysite performances, and to develop high temperature ceramic up to 1300°C (silico-aluminous refractory “S-Al-R”). Among all the mixtures tested, the mixture M6 provides good technical quality: Porosity (P)=21.75%; density (d)=1.94g/cm3; thermal shrinkage (R)=2.7% and flexural strength (Rf)=29.05MPa. Addition to the mixture (M6) of 25% of the recycled alumina “Rec-Al”, obtained from silico-aluminous refractory bricks waste, has substantially strengthened the mechanical performance of the silico-aluminous refractory (Rf=45.08MPa).