## 6 Conclusions  
This study explores the application of MSWI-FA, GGBFS, and MS, combined with cement, for the stabilization of industrial soils contaminated by heavy metals. This treatment not only makes the soil safer but also provides the opportunity to valorize industrial waste, offering significant economic and environmental benefits. Some conclusions can be drawn, as follows:* Fly ash and GGBFS, rich in silicon (Si) and aluminum, act as pozzolanic agents, enhancing the reactivity of the treated soil and promoting the formation of stable bonds with the cement. These chemical bonds create a robust structure that reduces soil permeability and improves its load-bearing capacity. * The use of marble sludge as an additional material not only enables the vaporization of industrial by-products but also enhances the cohesion of the treated soil, reducing the risk of concentration and improving its long-term stability. When combined with cement and pozzolanic materials, marble sludge contributes to improving the soil's overall quality, making it more stable and resistant to mechanical stress. * Using materials such as fly ash, blast furnace slag, and marble sludge helps reduce environmental impact compared to traditional methods, particularly when compared to cement, which produces higher greenhouse gas emissions. Stabilized soils are commonly used in road infrastructure as subbases or bases for roads, highways, and bike paths. In the construction sector, they serve as foundations for buildings and civil engineering works, improving soil bearing capacity and reducing the need for additional aggregates. They are also employed in industrial and logistics areas to create durable surfaces for yards, ports, and loading/unloading zones. In environmental rehabilitation projects, stabilized soils contribute to the redevelopment of degraded areas, such as former quarries or contaminated sites. Additionally, they are used in hydraulic works for the construction of embankments, canals, and containment basins. In the transportation sector, they enhance the stability of railway embankments and airport infrastructure. Several aspects of this work open avenues for further research and broader applications. Future studies should focus on the rheological characterization of the inert products produced by the new mixtures. Additionally, these products will need to be classified based on their characterization and designated for new uses. Another valuable line of investigation would involve testing other materials to fine-tune the mix design based on the specific contaminants present in the soil, optimizing the process for various types of contamination. A key aspect concerns the long-term durability of the treated soils. This can be studied, for example, through expansion tests to evaluate the possible swelling of the soil when exposed to humidity or variable climatic conditions, or pH tests to assess chemical changes over time. Specifically, the material's resistance to freeze-thaw cycles and humidity fluctuations is crucial for assessing the sustainability and safety of the treatment under varying environmental conditions such as the two mentioned. Currently, this work aims to refine the stabilization process, but an evaluation of long-term durability under variable environmental conditions is a critical goal for future research directions in terms of material's resistance to freeze-thaw cycles and humidity changes to better understand its ability to maintain stabilization over time. Future research will also include comparisons between newly developed inert products, evaluating not only their mechanical and environmental performance but also their long-term durability under different environmental conditions, to ensure more efficient and sustainable solutions for the remediation of contaminated industrial soils. Conceptualization: A.P. and F.F. ; Methodology: A.A. and G.D.C. ; Investigation: G.D.C., I.F. and F.C. ; Data Curation: A.P., A.A. and G.D.C. ; Writing--Original Draft Preparation: A.P., G.D.C.