ABSTRACT
This research was carried out to ascertain the suitability of Osara and Jamata River sand for moulding operation and Ajaokuta Foundry Sand was also tested along with the two sands under the same condition and their moulding properties were compared with that of American Foundrymens' Society (AFS) Standard. The Jamata River sand sample was collected from the River Niger flowing under the Murtala Bridge along Lokoja to Abuja road at a village called Jamata in Kogi State while the Osara river sand sample was collected from Osara River along Okene to Lokoja road in a village called Osara in Kogi State of Nigeria. The three sand samples were subjected to various laboratory tests under the same condition in accordance to the American Foundrymens' Society (AFS) standard of testing moulding sand by varying the water addition from 3% to 7% and bentonite which acts as a binder was also varied from 6% to 12%. The two sand deposits are about 80km apart and they are both about 60km from Ajaokuta Steel Company respectively. The result of the grain size distribution analysis of the three sand samples met with the AFS standard specification of moulding sand in that the bulk of the sand retained were on four consecutive sieves and the Grain Fineness Number (GFN) calculated from the grain size distribution results show that Osara river sand sample has GFN of 51.6 and Jamata has GFN of 65.1 while Ajaokuta Foundry Sand has 57.6. The XRF analysis shows that Osara has 82.5% SiO2 and Jamata has 86% SiO2 while Ajaokuta Foundry Sand has 94.3% SiO2 which indicate that the three sands met the AFS standard. The refractoriness of the three sands samples were tested by using pyrometric cone equivalent and none of the samples sintered at 15000C. The permeability of the three sand samples were within the ranges of 95 to 120mmWs which shows that the three sand can be used for both ferrous and nonferrous casting according to AFS standard. The results of the mechanical test (Tensile strength, green/dry compressive strength, green/dry shear strength) for the three sand samples show that the higher the percentage of water and bentonite addition, the higher the mechanical properties. The best mechanical properties were obtained at 12% bentonite with 7% water addition and at this point the two samples met the AFS standard. The result of the research shows that both Osara and Jamata river sand can be used for ferrous and nonferrous casting operation.