Suitability of Different Nigerian Sourced Natural Molding Sand for Green Sand Casting Using Scheffe’s Model

Abstract

The Nigerian foundry industry faces challenges in achieving optimal casting quality, largely due to the lack of standardized approaches to designing moulding sand mixtures. This study investigates the suitability of locally sourced sands—Zungeru, Bida, Minna, Jos, and Kaduna—for green sand casting, using Scheffe’s mixture design model as the design of experiment (DOE) technique. Synthetic sand mixtures (SSMs) were developed by combining natural sands with additives such as bentonite, coconut shell fibre, and rice husk fibre. A total of 35 experimental blends were analyzed for permeability, compressive strength, plastic index, and other key parameters following ASTM Standards D2434, D2216, D4318, and D2487 for permeability, moisture content, plastic index, and fineness modulus respectively. The findings reveal that Zungeru sand, in particular, met the requirements for Al-6063 green sand casting applications. This study shows the potential of optimizing natural sands for foundry applications, contributing to the development of sustainable and cost-effective casting processes in Nigeria.