INVESTIGATION INTO MOULDING CHARACTERISTICS OF SELECTED NIGERIAN BENTONITE CLAY SAMPLES

Bentonite clay is a key material in the foundry industry, widely used as a binder in sand molds for metal casting. Nigeria possesses vast deposits of Bentonite, yet industrial applications still rely on imported variants due to a lack of extensive research on local sources. This study investigates the molding characteristics of Bentonite clay samples collected from six Nigerian locations, evaluating properties such as refractoriness, green and dry compressive strength, green and dry shear strength, permeability, and compactibility. Standard foundry tests were conducted following American Foundry Society (AFS) guidelines. The results indicate significant variations in molding properties among the samples. Sample D exhibited the highest green compressive strength (82.05 KN/m²) and green shear strength (14.48 KN/m²), while Sample B demonstrated superior dry compressive strength (393.13 KN/m²) and dry shear strength (124.15 KN/m²), making them suitable for high-stress foundry applications. Additionally, the refractoriness of the samples exceeded 1200°C, confirming their suitability for metal casting. The successful production of aluminum alloy castings using these samples further supports their industrial viability. These findings emphasize the potential of Nigerian Bentonite to replace imported variants, reducing costs and fostering local industry growth.