Evaluation of Chemical and Physico-Mechanical Properties of some Nigeria Natural Clays Samples for Foundry Applications

Abstract

Studies have shown that Nigerian clays have not been fully utilized for foundry applications, either as refractories or even bonding clays, and are still being imported into the country. There is need to effectively exploit and adequately utilize the available natural resources to improve Nigeria economic activities, most especially during the present economic recession. Samples of clays were obtained from Auchi, Dada-Okelele (Ilorin), Kaba, Maraba-Rido, Mokwa and New-Bussa in Nigeria. The samples’ physico-mechanical properties were examined for its suitability for foundry/refractory applications. The results of the chemical analysis revealed that the samples belong to Alumino-Silicate refractories. The samples exhibited 35.3-96.2%, 17.1-28.7%, 1.72-2.34 g/cm3, 2.2-10.1%, 73-86 and >1300oC as values for percentage clay contents, apparent porosity, bulk density, permeability, linear shrinkage and refractoriness respectively. These values were within the standard range values of >35%, 22-30%, 17-2.4%, 2.0-10.1% and 25-90 required as percentage clay contents, apparent porosity, bulk density, permeability and linear shrinkage values respectively, for refractory clays/brick lining or alumina-silicates, kaolin and fireclays. Hence, the clays could suitably replace imported clays / ceramics in refractory applications, such as in production of earthen wares, chalk; as insulating refractories for casting and melting of low and medium temperature iron and steel. Appropriate utilization of these clays for local foundry applications will assist in addressing the problem of inadequate job, and over dependence on foreign goods.Keywords— Alumino-Silicate, Clay, Foundry, Moisture and Refractoriness