Development of Ceramic Foams Using Cast Iron Slag as a Raw Material

In this work experimental foams based on cast iron slag were made in order to investigate the potential application of cast iron slag (CIS) for the production of relatively economic high strength ceramic foams. The foams were processed using the slip cast method and as a base material Al2O3-SiO2 with a systematic addition of CIS from 25 % all the way to foams consisting of 100 % CIS. After sintering at 1473 K (1200oC) for two hours quantitative and qualitative determinations indicated that as the amount of CIS was increased in the experimental foams, the dominant phases formed were anorthite, pseudowollastonite and sillimanite. Determinations of the exhibited pore size and percent porosity indicated that the maximum values were found in the foams containing up of 100 % CIS. In addition, the density of the high CIS foams was reduced significantly (down to 1.8 g/cm3) as a result of the increased porosity. This was accompanied by a high compressive strength of the order of 16 MPa for the high CIS foams. Apparently, the combination of phases developed during foam sintering in the high CIS provide significant strength to the porous foam material.