## 3 Materials and Methods
### Green Material Characterization
#### 3.6.1 EDS/SEM Analysis  
The EDS analysis was chosen for its ability to provide detailed information on the mineral composition and the distribution of chemical elements during heat treatment. This technique is essential for identifying both active and inert mineral phases, enabling the optimization of production conditions and improving cementitious properties such as hydration activity and reactivity [64].  
The chemical composition of the selected materials, determined through EDS testing, is presented in Table 6.  
The results of the EDS analysis reflected the differing compositions of the industrial waste precursors. The average composition of MSWI-FA consisted of approximately 24.31 wt% calcium oxide, 21.20 wt% chloride, 16.35 wt% carbon monoxide, and 8.57 wt% sulfate. Calcium oxide was present in higher quantities than other elements, particularly  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Chemical** & & & & & \\
**Composition (wt\%)** & & & & & \\ \hline Fe\({}_{2}\)O\({}_{3}\) & 0.86 & 1.16 & 25.53 & 1.35 & 3.41 \\ CaO & 24.31 & 39.90 & 17.48 & 51.92 & 67.16 \\ CO & 16.35 & 14.13 & 11.29 & 22.74 & - \\ SiO\({}_{2}\) & 2.62 & 4.57 & 16.26 & 14.16 & 16.65 \\ Al\({}_{2}\)O\({}_{3}\) & 1.53 & 3.36 & 8.93 & 4,56 & 4.21 \\ SO\({}_{3}\) & 8.57 & 9.58 & - & - & 5.34 \\ MgO & 1.09 & 2.57 & 7.94 & 1.21 & 1.71 \\ Mn\({}_{2}\)O\({}_{3}\) & - & - & 3.44 & - & - \\ Cr\({}_{2}\)O\({}_{3}\) & - & - & 1.84 & - & - \\ NO\({}_{x}\) & - & - & 10.07 & - & - \\ SnO\({}_{2}\) & - & - & - & 2.20 & - \\ Na\({}_{2}\)O & 13.87 & 9.10 & - & 0.86 & - \\ K\({}_{2}\)O & 6.41 & 2.32 & - & 1.02 & 1.54 \\ TiO\({}_{2}\) & 0.36 & 0.98 & - & - & - \\ CIO & 21.20 & 8.77 & - & - & - \\ ZnO & 2.85 & 3.36 & - & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 6: Chemical composition in terms of equivalent oxides (wt%) of MSWI-FA, W-FA, GGBFS, MS and CEM.  
in comparison to the silica and alumina content. The chemical characterization of W-FA revealed significant differences between the two ash samples. Specifically, W-FA showed lower environmental risks in terms of chlorides. A significant reduction in chloride content was observed after the washing pretreatment of W-FA, resulting in a residual percentage of 8.77 wt%. Nearly 90% by weight of GGBFS consisted of iron, aluminum, magnesium, and silicon oxides, which can be attributed to the oxidation of metal components during the steelmaking process. Marble sludge contained 50% by weight of calcium oxide, 22.74% by weight of carbon oxide, and nearly 30% by weight of silica, alumina, and magnesium oxide. The chemical composition of the cement matched typical characteristics related to the raw materials and cement manufacturing process.  
Scanning electron micrographs of MSWI-FA, W-FA, GGBFS, and MS are shown in Figure 6.  
Figure 6 presents the results of the SEM analysis on MSWI-FA and Figure 6b on W-FA, with micrographs at low magnification (500\(\times\)) for MSWI-FA and at high magnification (3000\(\times\)) for W-FA. Figure 6c-e reveal the microstructure of CEM, GGBFS, and MS at 3000\(\times\).  
The micrographs of MSWI-FA reveal a rough and irregular surface. MSWI-FA exhibits a medium-fine particle distribution, with the fine particle fraction being predominant. However, when comparing the MSWI-FA micrographs to those of W-FA, it is evident that the particles in W-FA are larger than those in MSWI-FA.  
SEM analyses were conducted to characterize the morphology of GGBFS, marble sludge (MS), and cement.  
The SEM results indicated that both cement and MS have irregular surfaces and contain a higher presence of crystalline structures compared to GGBFS. In contrast, GGBFS has a rough, porous surface with a largely amorphous matrix and fewer crystalline phases. For marble sludge, the micrographs reveal a distribution of fine particles, and at higher magnifications, the presence of a rough and irregular surface along with crystalline phases is noticeable.  
Figure 6: Scanning electron micrographs of (**a**) MSWI-FA, (**b**) W-FA, (**c**) CEM, (**d**) GGBFS, and (**e**) MS.