MOULDING PROPERTIES OF RIVER NIGER SAND (IDAH DEPOSIT) BONDED WITH IYOLOKO CLAY AND CASSAVA STARCH

Abstract

The foundry properties of river Niger sand (Idah deposit) bonded with Iyoloko clay and cassava starch were evaluated. Impurities and other foreign objects were removed by washing and sorting, sieve analysis of Idah sand deposit revealed a grain fineness number (GFN) of 40.03 which belongs to the group of grain fineness number that has wide application in sand casting. Above 95% bulk of the sand was retained after the first few sieves, hence the sand was considered to have met the American Foundrymen’s Society (AFS) standard specification for moulding sand. Energy Dispersive X-Ray Fluorescence Spectrometer was used to carry out the chemical analysis of the sand and clay samples. From the results obtained, the sand was of high silica content (95.93%) while the clay was rich in silica and alumina contents (65.40% and 20.30% respectively). It was further observed that the sand deposit also maintained its refractoriness at above 1000 oC. Moulding properties investigated are green compression strength, dry compression strength, green shear strength, dry shear strength, permeability and compactibility were determined using a motor driven universal sand strength machine and its accessories and electric permeability meter. The mechanical and physical properties of the aluminium alloy casting produced with the local sand compared favourably with typical mechanical properties for aluminium alloys. Therefore, foundry moulds produced from this sand deposit bonded with Iyoloko clay and cassava starch is suitable for casting aluminium alloys.