Determination of the Suitability of River Gurara Bed Sand Bonded with Clay for Foundry Casting Moulds

Abstract

The study investigated foundry properties of bed sand from river Gurara located in Niger State, Nigeria for use in production of foundry casting moulds using bentonite or kaolin clay as binders. A quantity of representative sand sample collected according to AFS procedure was washed, sun dried, classified on vibrated sieves and used for the experiment works. Specimens bonded with 0.5-3% of either bentonite or kaolin clay were prepared in accordance with AFS standard and tested for refractoriness; permeability; green/dry compressive strengths; moisture content; green hardness and shatter index using equipment including moisture teller, universal strength machine, shatter index and Rockwell hardness testers. The BS classification sieve result showed it consisted of 42% medium and 27% fine sand that will produce castings with fine surface finish. The physiochemical analyses done with XRF machine showed the sand was made up of 88% silica with metal/alkali oxides including Fe₂O₃ (3.02%), K₂O (3.02%), Al₂O₃ TiO₂ (2.12%). It had refractoriness of 1,500^oC making it suitable for casting moulds for non-ferrous metals, light/heavy grey iron and some grades of steel. Tested foundry properties including permeability (167-136No); green compressive (26-38KN/m²), dry compressive strength (200-360KN/m²); hardness (65-80); shatter index (88-70) for kaolin bonded specimen and  (130-116); (18-34KN/m²); (182-238KN/m²); (48-54No); (110-76N0) for bentonite bonded specimen when compared with existing foundry standards also confirmed suitability of sand bonded with these clay for the applications mentioned.

Keywords: Gurara river, bed sand, Kaolin, Bentonite, Foundry

Keywords: Claims, Delivery, Administration

DOI: 10.7176/IEL/9-2-05

Publication date:March 31^st 2019