## 3 Results
### DSC-TG/MS Measurements
The formation of larnite was similar to the work published by [PERSON] et al. [6]. The quantitative PXRD and the DSC-TG analysis of the carbonated wollastonite (CO\({}_{2}\) + SO\({}_{2}\) + NO\({}_{2}\), 333 K, 2 MPa) for the content of carbonate were of similar magnitude (Rietveld: 58.4 \(\pm\) 0.5 wt.%; DSC-TG: 56 \(\pm\) 2.8 wt.%). Thermal (DSC-TG) and spectroscopic (MS) analyses on previously treated wollastonite with CO\({}_{2}\) at 333 K and 2 MPa is shown exemplarily in Figure 4. During heating, 25.7% of the weight was lost; 24.3% could be attributed to CO\({}_{2}\), i.e., to 55.8 wt.% carbonate in the sample (Figure 4, Table 3, Equation (2)). The MS curve (green) detected a maxima of the mass flow of H\({}_{2}\)O (Figure 4) at approximately 400 K, which decreased distinctly at 500 K. From 550 to 650 K the release of H\({}_{2}\)O increased again and dropped afterwards until 1050 K. The MS curve of CO\({}_{2}\) (Figure 4, magenta line) remained at a constant level until 700 K and increased slightly until 900 K, then it increased more distinctly and held a plateau until 950 K. Afterwards, a maximum at 1080 K was reached. At temperatures beyond 1080 K, no significant release of CO\({}_{2}\) could be observed. The TG curve (weight loss, Figure 4, black line) decreased with a small rate until 900 K. The loss of CO\({}_{2}\) could be observed clearly in the curve between 900 and 1080 K. Beyond 1100 K, the release of CO\({}_{2}\) stopped. The DSC signal (Figure 4, blue line) showed a maximum (endothermic) amplitude at 1080 K and correlated with the detected MS maximum of CO\({}_{2}\). At approximately 1150 K, a positive amplitude for the DSC signal could be observed and indicated  
Figure 2: Results of differential scanning calorimetry with thermogravimetry, coupled with a mass spectrometer (DSC-TG/MS) measurements on (**a**) wollastonite raw material, initial weight 20.3 mg; and (**b**) carbonated wollastonite, initial weight 15.2 mg. Measurements were carried out from 296 to 1273 K with a heating rate of 10 K/min. The black lines represent weight loss (wt.%). The blue lines show the DSC signal (mW). The green lines refer to the mass flow (A) for H\({}_{2}\)O. The mass flow (A) for CO\({}_{2}\) is shown by magenta lines [6]. the formation of Ca\({}_{2}\)SiO\({}_{4}\) (i.e., C\({}_{2}\)S, larnite), which was confirmed by PXRD of the TG sample. The formation of larnite was similar to the work published by [PERSON] et al. [6]. The quantitative PXRD and the DSC-TG analysis of the carbonated wollastonite (CO\({}_{2}\) + SO\({}_{2}\) + NO\({}_{2}\), 333 K, 2 MPa) for the content of carbonate were of similar magnitude (Rietveld: 58.4 \(\pm\) 0.5 wt.%; DSC-TG: 56 \(\pm\) 2.8 wt.%). Figure 4: Result of the DSC-TG/MS measurement of carbonated (at 2 MPa pure CO\({}_{2}\) and 333 K for 24 h in brine) wollastonite (initial weight 20.4 mg). Measurement from 296 to 1273 K with heating rate of 10 K/min. The weight loss (wt.%) is represented by the black line, the DSC signal (mW) by the blue line. The green line shows the mass flow (A) for H\({}_{2}\)O, and the magenta line the mass flow (A) for CO\({}_{2}\). Figure 3: Result of the DSC-TG/MS measurement of carbonated (at 2 MPa CO\({}_{2}\) + SO\({}_{2}\) + NO\({}_{2}\) and 333 K for 24 h in brine) wollastonite (initial weight 21.7 mg). Measurement from 296 to 1273 K with a heating rate of 10 K/min. The weight loss (wt.%) is represented by the black line, the DSC signal (mW) by the blue line. The green line shows the mass flow (A) for H\({}_{2}\)O, and the magenta line the mass flow (A) for CO\({}_{2}\).