A study of upland clay from ant-hills as a refractory material.

Abstract

This study was purposed to investigate the suitability of upland ant-hill clays for fabricating refractory bricks. The chemical composition of the anthill clay was determined using the Atomic Absorption Spectrophotometer (GBC SavantAA) and X-Ray Spectrometry. The chemical analysis revealed the presence of the elements which included; alumina, silica, iron oxide, titanium oxide, potassium, sodium, calcium, organic carbon, phosphate, zirconium, strontium, cranium, rubidium, magnesium, manganese, copper, zinc, yttrium and nitrogen. Wet and dry pressed samples were obtained by using the hydraulic press with a die mould (Hydraulina Laboratory Manual press- PW40) and slip casted samples were formed using a metallic brick mould. All dry pressed samples were found to be structurally inadequate due to development of strata, formation of cracks after firing. The wet pressed and slip casted samples were fired at a heating rate of 2°C/minute to a temperature of 534°C and held at this temperature for lhour then heated to 1150°C at a rate of 6°C/minute and held for 1 hour and then allowed to cool in the furnace at a rate of s°C/minute. All Samples fired at 11 S0°C were successfully retrieved and had no cracks or any other deformities. The Modulus of rupture was determined using the three point loading method (LLOYD INSTRUMENTS). Thin wet pressed fired samples had high MOR average values of 13826.08KPa for Nkombe, 1963.43KPa for Namagunga and 1510.23KPa for Kyambogo. The slip casted fired samples had an average MOR of 31.60Pa for Namagunga and 1l7.74Pa for Kyambogo. These suggested that sample forming methods have an effect on the modulus of rupture. The average MOR of the wet pressed fired samples of upland ant-hill clay was found to match that recommended by ASTM (American Society for Testing and Materials) standards for refractory materials and the percentage of the alumina in upland ant-hill clay showed quite close compliance with ASTM standards. This therefore means that based on the findings above, upland ant-hill clay is suitable for refractory materials.