Developing a foundry mould production system using continuously regenerated silica sand with specialised binder

Sand casting is a well-established method in the foundry industry, continuously innovated for sustainability. Single-use molds generate significant waste, prompting stricter regulations and higher disposal costs. Sodium silicate (waterglass) molds are gaining popularity due to their non-toxic composition and near-zero emissions. Regenerating mold remains into new sand is challenging, especially for waterglass binders. Mechanical wear-based regeneration is feasible but causes high sand losses. A pilot installation was developed for waterglass bound sand regeneration, achieving good casting quality despite low mold strength. The study identified remaining binder film as a key issue, requiring further research for reproducible quality regeneration sand. A heat treatment for regeneration sand was shown to return virgin sand levels of strength.