## 4 Results and Discussion
### Relevance of Methodology
Ideally, reaching these granulometric properties should be achieved under similar input energies from grinding, as excessive grinding has been shown to induce non-breakage effects that possibly could relate to improved reactivity [55]. The original slag and the three remelted slags, granulated on a laboratory scale, were ground using the same conditions in the present study. The specific surface areas were determined to be 0.622, 0.670, 0.702, and 0.705 m\({}^{2}\)/g for the original slag, 1200, 1300, and 1400 \({}^{\circ}\)C samples, respectively. Although the original slag was slightly coarser, the specific surface areas are within the same range. Based on the above, this methodology generated amorphous slags with comparable specific surface areas, which offers excellent prerequisites for comparing their reactivities. Figure 7: The literature data on previously studied compositions [18] compared to the industrial and synthetic slags of the present study. (**A**) CaO vs. FeO/SiO\({}_{2}\) ratio, and (**B**) Al\({}_{2}\)O\({}_{3}\) vs. FeO/SiO\({}_{2}\) ratio. Figure 9A illustrates the cumulative heat during 7 days of hydration recorded in the R\({}^{3}\) isothermal calorimeter experiments. An initial high rate of released heat during the first 14 h was recorded, possibly due to a high initial dissolution rate stemming from the entirely amorphous nature of the slags. During the dissolution of the slags, ions are released, which contribute to additional heat generation from the precipitated phase assemblage. Based on previous studies on iron silicate slags [21; 32], formed phases could constitute, e.g., calcium silicate hydrate (C-S-H) and calcium aluminum silicate hydrate (C-A-S-H) gels, as well as alumina ferric oxide tri-substituted (AFt) and monosubstituted (AFm). The kink in the cumulative heat, representing a changed heat flow after 14 h, is likely to be related to phase assemblage rather than the dissolution of a specific component since amorphous materials have been shown to dissolve congruently [28]. The progressively lower heat flows, representing the slopes of the curves, result from the gradual consumption of the SCM from dissolution and reactions. Figure 8: Diffractograms including calcite as internal standard. Figure 9: R\({}^{3}\) calorimeter results showing (**A**) cumulative heat and (**B**) evolved heat after 7 days with 3% error bars. Considering the results presented in Figure 9A, the four slags showed similar heat development patterns. Furthermore, the developed heat after 7 days, presented in Figure 9B, shows that the overall reactivities of the slags are comparable. According to [PERSON] and Scrivener [22], the R\({}^{3}\) calorimeter experiment has a standard error in the range of 2-3%. Based on these values, error bars of 3% were included in Figure 9B. Accounting for this error in the R\({}^{3}\) experiment, the values presented in Figure 9B do not differ from a statistical standpoint. Therefore, melting iron silicate slags in iron crucibles and granulating in water jets on a laboratory scale generates a slag that has the same reactivity as the industrially granulated slag. Furthermore, this conclusion is valid regardless of homogenization temperature at the achieved cooling rate. Similar observations regarding superheating have been shown for granulated blast furnace slags in a previous publication [56]. Based on the discussion related to the crystallinity of the slags, this conclusion is valid, provided crystallization does not occur due to excessively low homogenization temperatures or inadequate cooling rates.