Evaluation of Foundry Properties of Kwali Natural Sand Deposits for Casting Applications.

Abstract

Sand deposits of Kwali and its environs have been widely used for pottery works. There is need to investigate the suitability of Kwali sands for Foundry applications. Therefore, this study investigated the foundry properties of Kwali natural sand deposits from two selected areas, Gadabiu (sample A) and Kwali town (sample B). The sand samples were mixed by varying the moisture content: Sample A (8-10 %); Sample B (2-6 %). Properties of the sand samples were tested in accordance with American Foundry Society standard guidelines. In addition, sand samples from the two areas were used to prepare moulds for casting aluminium. Moisture content of these sand moulds influenced the properties evaluated. The grain fineness numbers and clay contents obtained from the analyses of sample A (fine particles) were 73.49 and 55.6%, and sample B (coarse-grained) were 87.78 and 35.7 %, respectively. Results of the properties investigated for sample A at 9 % moisture content include green compression strength (127.55 kN/m2), green shear strength (48.26 kN/m2) and permeability of 4.9, while sample B at 4% moisture content were green compression strength (84.81 kN/m2), green shear strength (58.61 kN/m2) and permeability of 6.0, which agree with the standards. Better aluminium casting was achieved from sample B at 4% moisture-mould compared to that of 6% moisture-mould. Sample A was suitable as facing sand because of its grains roundness and high fineness, although high plasticity prevented it from forming moulds. Therefore, Kwali sands can be used for foundry applications.