Efficient Recycling Process of Waste Sand with Inorganic Binder via Ultrasonic Treatment
Abstract
1. Introduction
2. Experimental Procedure
2.1. Preparation on the WSIB
2.2. Recycling Process of WSIB
2.3. Characteristics of Sand: Residual Binder Content, Particle Size Distribution, Surface Morphology, and Specific Surface Area
2.4. Evaluation of Bending Strength and the Amount of Gas Evolution of Recycled Sand Cores
2.5. Microstructural Analysis of the Interface Between A356 Al Castings and the Recycled Sand Cores
3. Results and Discussion
3.1. Results of Sand Characterization
3.2. Results of Characteristic of Sand Core
3.3. Result of Microstructural Analysis of the Interface Between A356 Al Castings and the Recycled Sand Cores
3.4. Economic Assessment of the Ultrasonic Recycling Process
4. Conclusions
- The ultrasonic recycling process achieved superior technical performance compared to conventional methods while offering significant operational advantages. Cavitation and acoustic streaming enabled a 92.3% recycling ratio within a simplified process sequence, removing the need for heat treatment and mechanical grinding steps. Therefore, URS had a lower residual binder content (0.33%) than CRS (0.85%), confirming the enhanced binder removal efficiency of ultrasonic treatment.
- Both the conventional and ultrasonic recycling processes produced recycled sands that substantially improved the bending strength of the core compared to using VS alone. The improvements in bending strength were driven by two factors. Increased specific surface area providing additional binder reaction sites and improved particle packing through wedge effects of optimized size distributions.
- The ultrasonic recycling process maintained the environmental advantages of inorganic binder systems while achieving superior casting quality. The volume of gas evolved from URS cores (11 ) was comparable to that of VS core (9 ) and lower than that of the CRS core (14 ). Furthermore, the porosity level at the interface between the URS core and A356 aluminum castings was measured at 0.26, similar to the 0.22 that observed with VS cores. The result in porosity level of castings suggests that the mechanical properties of A356 aluminum castings made with URS cores are comparable to those made with VS cores.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
- Herfurth, K.; Scharf, S. Casting, Springer Handbook of Mechanical Engineering, 2nd ed.; Springer: Gewerbestrasse, Switzerland, 2021; pp. 325–356. [Google Scholar] [CrossRef]
- Sawai, H.; Rahman, I.M.M.; Fujita, M.; Jii, N.; Wakabayashi, T.; Begum, Z.A.; Maki, T.; Mizutani, S.; Hasegawa, H. Decontamination of metal-contaminated waste foundry sands using an EDTA–NaOH–NH3 washing solution. Chem. Eng. J. 2016, 296, 199–208. [Google Scholar] [CrossRef]
- Mizuki, T.; Kanno, T. Establishment of casting manufacturing technology by introducing an artificial sand mold with furan resin and realizing a clean foundry. Int. J. Met. 2018, 12, 772–778. [Google Scholar] [CrossRef]
- Balulmath, A.B.; Sridhar, G.; Saranya, P. A Critical Review on Potential Use of Waste Foundry Sand in Geotechnical and Pavement Applications. In Proceedings of the Indian Geotechnical Conference, Kochi, India, 15–17 December 2022; Springer: Singapore, 2022; pp. 309–320. [Google Scholar] [CrossRef]
- Andrade, R.M.; Cava, S.; Silva, S.N.; Soledade, L.E.B.; Rossi, C.C.; Robertoleite, E.; Paskocimas, C.A.; Varela, J.A.; Longo, E. Foundry Sand Recycling in the Troughs of Blast Furnaces: A Technical Note. J. Mater. Process. Technol. 2005, 159, 125–134. [Google Scholar] [CrossRef]
- Ahmad, J.; Zhou, Z.; Martínez-García, R.; Vatin, N.I.; de-Prado-Gil, J.; El-Shorbagy, M.A. Waste Foundry Sand in Concrete Production Instead of Natural River Sand: A Review. Materials 2022, 15, 2365. [Google Scholar] [CrossRef] [PubMed]
- Khan, M.M.; Mahajani, S.M. Chemical reclamation of waste green foundry sand and its application in core production. Sustain. Chem. Clim. Action 2024, 4, 100038. [Google Scholar] [CrossRef]
- Deng, A.; Tikalsky, P. Metallic characterization of foundry by-products per waste streams and leaching protocols. J. Envrion. Eng. 2006, 132, 586–595. [Google Scholar] [CrossRef]
- Deng, A.; Tikalsky, P. Geotechnical and leaching properties of flowable fill incorporating waste foundry sand. Waste Manag. 2008, 28, 2161–2170. [Google Scholar] [CrossRef] [PubMed]
- Kmita, A.; Dańko, R.; Holtzer, M.; Dańko, J.; Drożyński, D.; Skrzyński, M.; Tapola, S. Eco-Friendly Inorganic Binders: A Key Alternative for Reducing Harmful Emissions in Molding and Core-Making Technologies. Int. J. Mol. Sci. 2024, 25, 5496. [Google Scholar] [CrossRef] [PubMed]
- Rayjadhav, S.B.; Mhamane, D.A.; Shinde, V.D. Assessment of sand reclamation techniques and sand quality in thermal reclamation. Int. J. Product. Qual. Manag. 2020, 30, 343. [Google Scholar] [CrossRef]
- Wan, P.; Zhou, J.; Li, Y.; Yin, Y.; Peng, X.; Ji, X.; Shen, X. Kinetic analysis of resin binder for casting in combustion decomposition process. J. Therm. Anal. Calorim. 2022, 147, 6323–6336. [Google Scholar] [CrossRef]
- Silva, E.C.; Masiero, I.; Guesser, W.L. Comparing sands from different reclamation processes for use in the core room of cylinder heads and cylinder blocks production. Int. J. Met. 2020, 14, 706–716. [Google Scholar] [CrossRef]
- Czerwinski, F.; Mir, M.; Kasprzak, W. Application of cores and binders in metalcasting. Int. J. Cast Met. Res. 2015, 28, 129–139. [Google Scholar] [CrossRef]
- Glowacki, S.M.; Crandell, C.R.; Cannon, G.R.; Clobes, F.S.; Voigt, J.K.; Furness, R.C.; McComb, J.C.; Knight, B.A. Emissions studies at a test foundry using an advanced oxidation-clear water system. AFS Trans. 2003, 111, 579–598. [Google Scholar]
- Holtzer, M.; Kmita, A. Mold and Core Sands in Metalcasting: Chemistry and Ecology, 1st ed.; Springer: Gewerbestrasse, Switzerland, 2020; pp. 83–107. [Google Scholar] [CrossRef]
- Wang, Y.; Zhang, Y.; Su, L.; Li, X.; Duan, L.; Wang, C.; Huang, T. Hazardous air pollutant formation from pyrolysis of typical Chinese casting materials. Environ. Sci. Technol. 2011, 45, 6539–6544. [Google Scholar] [CrossRef]
- Wang, Y.; Cannon, F.S.; Salama, M.; Goudzwaard, J.; Furness, J.C. Characterization of hydrocarbon emissions from green sand foundry core binders by analytical pyrolysis. Environ. Sci. Technol. 2007, 41, 7922–7927. [Google Scholar] [CrossRef]
- Anwar, N.; Jalava, K.; Orkas, J. Experimental study of inorganic foundry sand binders for mold and cast quality. Int. J. Met. 2023, 17, 1697–1714. [Google Scholar] [CrossRef]
- Dańko, R.; Kmita, A.; Holtzer, M.; Dańko, J.; Lehmhus, D.; Tapola, S. Development of inorganic binder systems to minimise emissions in ferrous foundries. Sustain. Mater. Technol. 2023, 37, e00666. [Google Scholar] [CrossRef]
- Polzin, H. Inorganic Binders for Mould and Core Production in the Foundry, 1st ed.; Fachverlag Schiele und Schön GmbH: Berlin, Germany, 2014; pp. 105–120. [Google Scholar]
- Fortini, A.; Merlin, M.; Raminella, G. A comparative analysis on organic and inorganic core binders for a gravity diecasting Al alloy component. Int. J. Met. 2022, 16, 674–688. [Google Scholar] [CrossRef]
- Anwar, N.; Major-Gabryś, K.; Jalava, K.; Orkas, J. Effect of additives on heat hardened inorganic solid foundry binder. Int. J. Met. 2025, 19, 129–144. [Google Scholar] [CrossRef]
- Jelinek, P. Pojivové Soustavy Slévárenských Formovacích Směsí, 1st ed.; OFTIS: Ostrava, Czech Republic, 2004; pp. 156–158. [Google Scholar]
- Wang, J.N.; Fan, Z.T. Freezing-mechanical reclamation of used sodium silicate sands. Int. J. Cast. Metal. Res. 2010, 23, 257–263. [Google Scholar] [CrossRef]
- Fan, Z.T.; Wang, H.F. Research and new advances in application of sodium silicate sand casting technology. MW Met. Form. 2011, 19, 23–26. [Google Scholar]
- Gong, X.L.; Hu, S.L.; Fan, Z.T. Research, application and development of inorganic binder for casting process. China Foundry 2024, 21, 461–475. [Google Scholar] [CrossRef]
- Kim, K.H.; Bae, M.A.; Lee, M.S.; Park, H.; Baek, J.H. Regeneration of used sand with sodium silicate binder by wet method and their core manufacturing. J. Mater.Cycles Waste 2021, 23, 121–129. [Google Scholar] [CrossRef]
- Hu, S.; Gong, X.; Wu, W.; Cai, G.; Ren, W.; Fan, Z. A Novel Reclamation Method of Chemical–Mechanical Grinding for Inorganic Binder Waste Sand in Aluminum Alloy Casting Process. Int. J. Met. 2024, 19, 1569–1578. [Google Scholar] [CrossRef]
- Wen, J.; Dong, H.; Zeng, G. Application of zeolite in removing salinity/sodicity from wastewater: A review of mechanisms, challenges and opportunities. J. Clean. Prod. 2018, 197, 1435–1446. [Google Scholar] [CrossRef]
- Xue, A.; Tang, Y.; Li, Y.; Dai, W.; Liu, J.; Wang, H. Reclaiming sodium silicate into diatom. J. Clean. Prod. 2025, 486, 144575. [Google Scholar] [CrossRef]
- Wang, L.; Jiang, W.; Gong, X.; Liu, F.; Fan, Z. Recycling water glass from wet reclamation sewage of waste sodium silicate-bonded sand. China Foundry 2019, 16, 198–203. [Google Scholar] [CrossRef]
- Nguyen, D.D.; Ngo, H.H.; Yoon, Y.S.; Chang, S.W.; Bui, H.H. A new approach involving a multi-transducer ultrasonic system for cleaning turbine engines’ oil filters under practical conditions. Ultrasonics 2016, 71, 256–263. [Google Scholar] [CrossRef] [PubMed]
- Choi, J.; Kim, T.H.; Kim, H.Y.; Kim, W. Ultrasonic washing of textiles. Ultrason. Sonochem. 2016, 29, 563–567. [Google Scholar] [CrossRef] [PubMed]
- Lais, H.; Lowe, P.S.; Gan, T.H.; Wrobel, L.C. Numerical modelling of acoustic pressure fields to optimize the ultrasonic cleaning technique for cylinders. Ultrason. Sonochem. 2018, 45, 7–16. [Google Scholar] [CrossRef] [PubMed]
- Yu, C.; Huang, X.; Fan, Y.; Deng, Z. A new household ultrasonic cleaning method for pyrethroids in cabbage. Food Sci. Hum. Wellness 2020, 9, 304–312. [Google Scholar] [CrossRef]
- Huang, X.; Niu, G.; Xie, Y.; Chen, X.; Hu, H.; Pan, G. Application of ultrasonic cavitation in ship and marine engineering. J. Mar. Sci. Appl. 2024, 23, 23–38. [Google Scholar] [CrossRef]
- Fulford, M.R.; Stankiewicz, N.R. Cleaning methods for dental instruments. Br. Dent. J. 2023, 235, 105–111. [Google Scholar] [CrossRef]
- Ko, E.Y.; Kim, K.H.; Baek, J.H.; Hwang, I.; Lee, M.S. Wet regeneration of waste artificial sand used in sand casting using chemical solutions. Environ. Eng. Res. 2021, 26, 200421. [Google Scholar] [CrossRef]
- Thomas, S. Mold&Core Test Handbook, 5th ed.; American Foundry Society: Schaumburg, IL, USA, 2019; pp. 21–22. [Google Scholar]
- KS L 3314:2017; Testing Method of Bending Strength for Insulating Fire Bricks. Korean Agency for Technology and Standards: Seoul, Republic of Korea, 2017.
- Yamashita, T.; Ando, K. Low-intensity ultrasound induced cavitation and streaming in oxygen-supersaturated water: Role of cavitation bubbles as physical cleaning agents. Ultrason. Sonochem. 2019, 52, 268–279. [Google Scholar] [CrossRef]
- Uemura, Y.; Sasaki, K.; Minami, K.; Sato, T.; Choi, P.K.; Takeuchi, S. Observation of cavitation bubbles and acoustic streaming in high intensity ultrasound fields. Jpn. J. Appl. Phys. 2015, 54, 07HB05. [Google Scholar] [CrossRef]
- Park, R.; Choi, M.; Park, E.H.; Shon, W.J.; Kim, H.Y.; Kim, W. Comparing cleaning effects of gas and vapor bubbles in ultrasonic fields. Ultrason. Sonochem. 2021, 76, 105618. [Google Scholar] [CrossRef]
- Chahine, G.L.; Kapahi, A.; Choi, J.K.; Hsiao, C.T. Modeling of surface cleaning by cavitation bubble dynamics and collapse. Ultrason. Sonochem. 2016, 29, 528–549. [Google Scholar] [CrossRef]
- Lee, Y.; Kim, J.; Ha, T.; Kang, B.; Kim, Y. Effect of Stable and Transient Cavitation on Ultrasonic Degassing of Al Alloy. Metals 2024, 14, 1372. [Google Scholar] [CrossRef]
- Cheng, Y.H.; Zhu, B.L.; Yang, S.H.; Tong, B.Q. Design of concrete mix proportion based on particle packing voidage and test research on compressive strength and elastic modulus of concrete. Materials 2021, 14, 623. [Google Scholar] [CrossRef]
- Kwan, A.K.H.; Chan, K.W.; Wong, V. A 3-parameter particle packing model incorporating the wedging effect. Powder Technol. 2013, 237, 172–179. [Google Scholar] [CrossRef]
- Gyarmati, G.; Budavári, I.; Fegyverneki, G.; Varga, L. The effect of sand quality on the bending strength and thermal distortion of chemically bonded sand cores. Heliyon 2021, 7, e07624. [Google Scholar] [CrossRef]
- Vasková, I.; Varga, L.; Prass, I.; Dargai, V.; Conev, M.; Hrubovčáková, M.; Demeter, P. Examination of behavior from selected foundry sands with alkali silicate-based inorganic binders. Metals 2020, 10, 235. [Google Scholar] [CrossRef]
- Li, J.; Zhang, H.; Hu, S.; Du, M.; Xiang, T.; Chen, J.; Cheng, Y. Wettability, flowability and core bending strength of wet silica sand particles based on the interfacial properties of liquid silicate binders. Powder Technol. 2024, 433, 119195. [Google Scholar] [CrossRef]
- Korea Electric Power Corporation, Electricity Tariff Structure. 2025. Available online: https://online.kepco.co.kr/PRM015D00 (accessed on 5 August 2025).
- Kim, K.H. Wet Regeneration and Optimization for Circular Use of Foundry Sand in Casting Process. Ph.D. Thesis, University of Ulsan, Ulsan, Republic of Korea, 2021. Available online: https://oak.ulsan.ac.kr/handle/2021.oak/5645 (accessed on 5 August 2025).
Sieve Size (Mesh) | Multiplier | Products () | |||
---|---|---|---|---|---|
VS | WSIB | CRS | URS | ||
20 | 0.1 | 0.3 | 0.1 | 0.1 | 0.1 |
30 | 0.2 | 3.5 | 3.1 | 2.7 | 3.1 |
40 | 0.3 | 16.9 | 13.7 | 12.8 | 13.5 |
50 | 0.4 | 5.9 | 8.4 | 8.1 | 8.0 |
70 | 0.5 | 2.8 | 4.7 | 6.6 | 5.5 |
100 | 0.7 | 1.3 | 2.5 | 2.9 | 2.6 |
140 | 1 | 0.7 | 3.0 | 3.8 | 3.0 |
200 | 1.4 | 0.2 | 0.8 | 1.8 | 0.8 |
270 | 2 | 0.2 | 1.0 | 0.8 | 0.8 |
PAN | 3 | 0 | 0.3 | 0.3 | 0.3 |
AFS-GFN | 31.8 | 37.5 | 39.9 | 37.7 |
Sand | ) |
---|---|
VS | 0.04 |
WSIB | 0.11 |
CRS | 0.07 |
URS | 0.06 |
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Ha, T.; Kim, J.; Lee, Y.; Kang, B.; Baek, J.; Kim, K.; Kim, Y. Efficient Recycling Process of Waste Sand with Inorganic Binder via Ultrasonic Treatment. Appl. Sci. 2025, 15, 8988. https://doi.org/10.3390/app15168988
Ha T, Kim J, Lee Y, Kang B, Baek J, Kim K, Kim Y. Efficient Recycling Process of Waste Sand with Inorganic Binder via Ultrasonic Treatment. Applied Sciences. 2025; 15(16):8988. https://doi.org/10.3390/app15168988
Chicago/Turabian StyleHa, Taekyu, Jongmin Kim, Youngki Lee, Byungil Kang, Jaeho Baek, Kyungho Kim, and Youngjig Kim. 2025. "Efficient Recycling Process of Waste Sand with Inorganic Binder via Ultrasonic Treatment" Applied Sciences 15, no. 16: 8988. https://doi.org/10.3390/app15168988
APA StyleHa, T., Kim, J., Lee, Y., Kang, B., Baek, J., Kim, K., & Kim, Y. (2025). Efficient Recycling Process of Waste Sand with Inorganic Binder via Ultrasonic Treatment. Applied Sciences, 15(16), 8988. https://doi.org/10.3390/app15168988