Sustainability Assessment of Thermal and Mechanical Reclamation of Foundry Chromite Sand

Abstract

After usage, foundry chromite sand is recycled to reduce production costs and comply with environmental regulations. Thermal and mechanical reclamation are the most prominent methods of sand recycling. The sand reclamation techniques used in the foundry sector are typically not evaluated through the green alternative or environmental sustainability concept’s lenses. When contrasting mechanical and thermal reclamation, operational costs are the main factor to be taken into account. Therefore, this study compares mechanical and thermal reclamation of chromite sand by replicating the industrial processes in simulated laboratory tests. The methodology is designed to quantify the production of fine particles during reclamation, which has an array of negative effects on the environment, human health, the economy, and society. The findings show that, in general, mechanical reclamation produced more fine particles than thermal reclamation. The disparity in terms of fine percentage between the two processes could occasionally be as high as 15%. Therefore, mechanical reclamation was a less effective procedure than thermal reclamation when considering environmental sustainability, especially the impact on human health, which goes against conventional wisdom in the foundry sector. Keywords sand recycling; chromite sand; environmental sustainability; green process

Thermal reclamation of used sand produced by binder jetting processes

“…About 25 000 tonnes of used foundry chromite sand and 350 000 tonnes of used foundry silica sand is dumped each year in South Africa [7]. As landfill capacity becomes increasingly limited, reducing the amount of waste generated, including used sand, is important for sustainable waste management [8]. If the used sand is not properly managed or recycled, it can contribute to waste generation.…”