Comparative study of emissions from molds manufactured with inorganic binders, organic binders and by green molding
1) Pilot Foundry plant testing methodology and results
Nine different mold and core configurations were used to conduct this study at the AZTERLAN Pilot Foundry Plant.
Emissions were quantified using closed-chamber tests (see images below), designed specifically for the GREEN CASTING project. This controlled environment minimizes the influence of external factors, allowing direct comparisons between the different molding systems and a more accurate assessment of the environmental impact of each system. Furthermore, the use of a closed chamber ensures a high degree of reproducibility and experimental control, improving the reliability of the data obtained.
Molten steel was poured into the core-mounted molds, and the following emissions were measured: BTEX (benzene, toluene, ethylbenzene, xylenes); PAHs (polycyclic aromatic hydrocarbons); phenol; formaldehyde; particulate matter and crystalline silica; and gases (CO, SO2, NOx).
The results obtained demonstrate the significant environmental benefits of inorganic binders in foundry applications, achieving substantial reductions in various air pollutants. These results are summarized below:
- Inorganic systems reduced BTEX emissions by 65–71% compared to green sand molding ones, and reductions higher than 90% were obtained in comparison with organic binders.
- Benzene was the predominant BTEX component (>60%) in most systems.
- Inorganic binders showed a reduction in particulate matter emissions greater than 98% compared to organic furanic and phenolic urethane systems.
- Organic systems generated higher NOx and SO2 emissions, while green sand and furanic systems had the highest CO emissions.
- Regarding PAHs, inorganic binders achieved reductions of greater than 94% compared to organic binders and more than 90% compared to green sand.
Authors:
David Valle (Metalúrgica Madrileña, S.A.), Erika Garitaonandia (AZTERLAN), Andoni Ibarra (AZTERLAN), Javier Abello (Metalúrgica Madrileña, S.A.), Ramón Domínguez (Metalúrgica Madrileña, S.A.)
Keywords:
cast iron, foundry, binders, inorganic binders, organic binders, green molding, foundry sand, foundry cores.
Related contents:
2) Study of emissions in an industrial manufacturing plant
To compare the results obtained in the pilot plant studies, measurements were performed at the facilities of Metalúrgica Madrileña S.A., where various parts were manufactured using molds made by inorganic process. Molten steel was cast in these molds and emissions were measured showing the following results:
As shown in the table, measurements of other environmental parameters were made, all of which were below the legal limits established for Spain. This shows that the values obtained by using inorganic binders are far below the limits established by law.
