Effects of Grog Additions on Some Refractory Properties of Raw (Abusoro) Kaolin Clay Deposit for Furnace Lining

Abstract

The influence of the weight of grog on some refractory properties of raw Abusoro clay samples found in Abusoro Village, Ondo State, Nigeria was evaluated. These samples were presented for refractory tests (apparent porosity, linear shrinkage, refractoriness, bulk density and cold crushing strength). The weights of the grog were varied from 20-40 wt. % in the blend. The chemical and microstructural examinations of the untreated alumino-silicate Abusoro clay samples indicated that they are abundant in silica, SiO2 (62.74wt. %) and alumina, Al2O3 (31.42wt. %). Other minor compounds found are Fe2O3 (1.43%), K2O (0.30%) with no trace amounts of MgO (0.00); therefore, they are regarded as alumino-silicate. Particular observation is made on MgO with zero amounts and the total of K2O + Na2O + MgO which are less than 2% in the clay samples. These results signify that the clay possesses high viability for manufacturing of refractory bricks, pulp and paper, ceramics, fertilizers, paint and cement. The performance evaluations of the refractory bricks measured indicated acceptable and satisfactory results vis-à-vis standard refractory properties for refractory fireclay bricks. However, the apparent porosity (43.2%) and CCS (21.21MPa) obtained for Abusoro clay sample at 30% weight of grog may as well be suitable for insulating refractory applications. The high apparent porosity could be an indication of high content of silicon oxide in the raw clay.