The production of iron castings in cupola furnaces is a significant industrial process that has a notable impact on the environment. This paper examines and describes the environmental impact of this process, specifically focusing on the generation, characterization, and utilization of waste materials through data analysis and collection. Approximately one hundred and two million metric tons of castings are produced worldwide each year, with approximately one ton of foundry waste generated for every ton of castings. The slag from this waste can amount to as much as 7.14 million metric tons annually. Most of the slag ends up in landfills, which is expensive and represents a waste of this potential secondary raw material. Therefore, it is necessary to find ways to utilize this waste in other processes or industrial sectors. Cupola slag, given its high phosphorus content, can be used as agricultural fertilizer or in the production of ceramic foam used in foundries as filters during casting. In the construction industry, slag can be used in the production of concrete as a partial substitute for fine aggregate. This concept not only mitigates the environmental impact of waste disposal, but also aligns with the circular economy concept, promoting resource efficiency.