Effects of ball milling on particle size distribution and microstructure of eggshells for applications in metal matrix composites

Eggshells are agricultural waste obtained from avian food sources. In the bid to improve production processes through sustainable and lean routes, waste materials have been integrated into materials and operation production sectors such as metal matrix composites, biodiesel, medicine, and microbiology among others. This work using ball milling times of 0, 15, 30, 45, and 60 mins attempts to characterize and the study the effects of ball milling on microstructure and morphology of eggshells. Using 125 mm sieve mesh. The particle size distribution was also investigated with results showing percentage particle retention of 88.89%, 62.26%, 46.52%, 27.30% and 9.32% for 0, 15, 30, 45, and 60 mins respectively. Density values for the eggshells using the Le Chatelier's principle shows density of 2.47 g/cm³ while the XRD analysis shows the presence of predominantly calcite (CaCO₃).