Thermal reclamation of used sand produced by binder jetting processes

Abstract

The binder jetting process for the manufacturing of sand moulds and cores for foundry applications generates appreciable quantity of used sand. This sand is generally discarded to dedicated landfills as a waste management practice in the country. This study therefore, explores the thermal reclamation of used silica sand. The used silica sand was heated in a muffle furnace at temperatures from 500˚C to 900˚C in order to burn off the coating material made of sulphonic acid and furfuryl alcohol. The results showed that heating the used silica sand samples at 600˚C for 10 and 15 minutes produced results close to virgin sand. The pH values obtained demonstrated that the reclaimed sand can be reused for additive manufacturing processes with the strength tests specimens reaching 220 N/cm2. Sand reclamation reduces the amount of waste sand that needs to be disposed, leading to lower disposal cost and potentially reducing landfill pollution.