Use of Cores with Inorganic Binder to Produce Thin-Walled Nodular Iron Castings
DOI:
https://doi.org/10.24425/afe.2025.153786Abstract
One of the primary issues in foundries is the emission of components that arise from the pyrolysis of organic substances during the pouring phase. This issue is particularly relevant in ferrous foundries. For this reason, the European Community has promoted the project Green Casting LIFE 21-ENV-FI-101074439, which aims at the industrial-scale implementation of the use of inorganic binders for the production of cast iron or steel castings. The work described in this paper shows that producing thin-walled castings in SIMO cast iron (a type of nodular cast iron characterized by high silicon and molybdenum content) using sand cores made with inorganic binders is possible, thanks to a new generation of products. In particular, the study is centered on an analysis of the results obtained from four tests conducted in a ferrous foundry with the aim of evaluating the feasibility of using inorganic cores in the production of exhaust manifolds for the truck sector. These experiments highlighted that, even when used at temperatures above 1400ºC, inorganic binders can guarantee satisfactory results in terms of the mechanical and technological properties of the cores, especially during the de-coring phase of the castings. Indeed, the castings obtained presented a quality that is comparable with those produced using other traditional technologies; this could represent a valuable opportunity for ferrous foundries interested in resolving or mitigating the problem of odors and pollution reduction; moreover, it confirms that inorganic binders, indicated as BAT (Best Available Technology) in the BREF Final Draft (released in February 2024), can be used to manufacture cores intended for the green sand molding process in cast iron foundries.References
[1] EU-BRITE. 2023. BAT reference documents. Retrieved July 29, 2024, from https://eippcb.jrc.ec.europa.eu/reference.
[2] European Commission. (2010) Directive 2010/75/EU of the European Parliament and of the Council of 24 November 2010 on industrial emissions. Retrieved July 29, 2024, from https://eur-lex.europa.eu/eli/dir/2010/75/oj.
[3] EU BRITE. (2022). Ferrous Metals Processing Industry. Retrieved July 29, 2024, from https://eippcb.jrc.ec.europa.eu/reference/ferrous-metals-processing-industry.
[4] Fortini, A., Merlin, M. & Raminella, G. (2022). A comparative analysis on organic and inorganic core binders for a gravity die casting Al alloy component. International Journal of Metal casting. 16(2), 674-688. https://doi.org/10.1007/s40962-021-00628-1.
[5] Tiedje, N., Crepaz, R., Eggert, T. & Bey, N. (2010). Emission of organic compounds from mould and core binders used for casting iron, aluminium and bronze in sand moulds. Journal of Environmental Science and Health Part A. 45(14), 1866-1876[ . https://doi.org/10.1080/10934529.2010.520595.
[6] Wang, Y., Cannon, F. S., Salama, M., Goudzwaard, J. & Furness, J. C. (2007). Characterization of hydrocarbon emissions from green sand foundry core binders by analytical pyrolysis. Environmental science & technology. 41(22), 7922-7927. https://doi.org/10.1021/es0716570.
[7] Czerwinski, F., Mir, M. & Kasprzak, W. (2015). Application of cores and binders in metalcasting. International Journal of Cast Metals Research. 28(3), 129-139. https://doi.org/10.1179/1743133614Y.0000000140.
[8] I zdebska-Szanda, I. & Balinski, A. (2011). New generation of ecological silicate binders. Procedia Engineering. 10, 887-893. https://doi.org/10.1016/j.proeng.2011.04.146.
[9] Xin, F. H., Liu, W. H., Song, L. & Li, Y. M. (2020). Modification of inorganic binder used for sand core-making in foundry practice. China Foundry. 17, 341-346. https://doi.org/10.1007/s41230-020-0018-2.
[10] Zaretskiy, L. (2016). Modified silicate binders new developments and applications. International Journal of Metalcasting. 10(1), 88-99. https://doi.org/10.1007/s40962-015-0005-3.
[11] Song, L., Liu, W. H., Li, Y. M. & Xin, F. H. (2019). Humidity-resistant inorganic binder for sand core making in foundry practice. China foundry. 16, 267-271. https://doi.org/10.1007/s41230-019-8169-8.
[12] Fratta, G., Stefani, I., Tapola, S. & Saetta, S. (2024). Green innovation practices: a case study in a foundry. Journal of Manufacturing and Materials Processing. 8(3), 111, 1-12. https://doi.org/10.3390/jmmp8030111.
[13] David, P., Massone, J., Boeri, R. & Sikora, J. (2004). Mechanical properties of thin wall ductile iron-influence of carbon equivalent and graphite distribution. ISIJ international. 44(7), 1180-1187. https://doi.org/10.2355/isijinternational.44.1180.
[14] Heidari, E., Boutorabi, S. M. A., Honaramooz, M. T. & Campbell, J. (2021). Ablation casting of thin-wall ductil iron. International Journal of Metalcasting. 16, 166-177. https://doi.org/10.1007/s40962-021-00579-7.
[15] Sand Team, Geopol. (2015). GEOPOL – ecological geopolymer-based inorganic binder system. Retrieved October 24, 2024, from https://www.sandteam.cz/en/binder-production.
[16] PEAK Deutschland GmbH (2024). The binder systems. Retrieved October 24, 2024, from https://www.peak-giesserei.de/en/bindersysteme
[17] Foseco - Vesuvius Group. (2024). Silicate Binders. Retrieved October 24, 2024, from https://www.foseco.com/en/glossary/silicate-binders.
[18] ASK Chemicals. (2024). INOTEC inorganic-binder-system. Retrieved October 24, 2024, from https://www.ask-chemicals.com/foundry/inotec-inorganic-binder-system.
[19] Haynes, W. M., Lide, D. R. & Bruno, T. J. (2013-2014). CRC Handbook of chemistry and physics. National institute of standards and technology.
[20] Spanidis, P. M., Pavloudakis, F. & Roumpos, C. (2021). Introducing the IDEF0 methodology in the strategic planning of projects for reclamation and repurposing of surface mines. Materials Proceedings. 5(1), 26, 1-8. https://doi.org/10.3390/materproc2021005026.
