Green industrial scale casting production using engineered molding materials: Sustainable strategies to reduce process gas emissions

The article presents two innovative inorganic binder systems based on sodium silicate or geopolymers for molds and cores, as well as several sand mix combinations in the mold/core system. The performed research provides unique data on gas and particulate matter emissions from industrial-scale casting production at the Odlewnie Polskie S.A. (OPSA) iron foundry in Poland. A series of test measurements were carried out to measure process emissions of gases such as BTEX (benzene, toluene, ethylbenzene and xylenes), PAHs (polycyclic aromatic hydrocarbons), phenol, formaldehyde, CO, CO₂, SO₂, NOx, TVOC (total volatile organic compounds) and particulate matter and crystalline silica generated during the production of castings weighing 100–500 kg and made of cast iron alloys. As a result of the tests, seven series of industrial measurements were performed on various types of sand mix for use in mold/core systems, three for systems using a homogeneous sand mix and four for heterogeneous mold/core systems. These meet the requirements for low emissions of harmful gases in the serial production of cast iron castings. Using homogeneous molding sand technology for green casting production significantly reduced the emission of hazardous substances (BTEX reduced by over 90 %, PAHs by over 80 %, and crystalline silica by over 50 %) from foundry molds by changing the molding sand technology from organic binder code PS to inorganic binders code CK and G. Key findings from industrial-scale trials indicate that the inorganic binders described below, encourage the expansion of this technology.

Funding: The research is financed within the GREEN CASTING LIFE project. The GREEN CASTING LIFE project is co-funded by the European Union’s LIFE program under grant agreement LIFE21-ENV-FI-101074439. The views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or CINEA. Neither the European Union nor the granting authority can be held responsible for them.

The GREEN CASTING LIFE project (LIFE21-ENV-FI-101074439) is co-funded by the National Fund for Environmental Protection and Water Management (NFOŚiGW) under grant agreement 276/2023/Wn-06/OZ-PO-LF/D.