## 3 Results and Discussion
### DSC-TG/MS/IR Measurements  
DSC-TG/MS/IR measurement of the raw material and the carbonated wollastonite were carried out to determine the entire content of water and carbonate in the material because X-ray amorphous carbonate could not be determined with PXRD, when additional amorphous phases (SiO\({}_{2}\)) are also present in the mixtures. DSC-TG/MS/IR measurements as shown in Figure 5 were performed with the raw material. During the measurement, the sample lost 2.1% of its weight. 1.7 wt % were associated with CO\({}_{2}\)  
Figure 4: PXRD of Rietveld analysis [36; 37; 38] of carbonated wollastonite (carbonated at 333 K, 2 MPa, with 24 h reaction time). Three crystalline phases and an amorphous content were determined by adding an internal TiO\({}_{2}\)-standard of known weight: wollastonite (cyan), calcite (magenta) and aragonite (purple). Figure 3: PXRD of Rietveld analysis [36; 37; 38] of the used raw material. Three crystalline phases and an amorphous content were determined by adding an internal TiO\({}_{2}\)-standard of known weight: wollastonite (cyan), calcite (magenta) and aragonite (purple). which results in original content of 3.9 wt % carbonate in the sample (Figure 5, Equation (2)). At the beginning of the experiment only H\({}_{2}\)O were detected by mass spectrometry. The detected mass flow of H\({}_{2}\)O (Figure 5, green line) decreased from 400 K to 800 K. From 800 K to 1050 K only CO\({}_{2}\) were measured by mass spectrometry. The mass flow of CO\({}_{2}\) reached its maximum at approximately 1000 K (Figure 5, magenta line). The measured weight loss (Figure 5, black line) decreased slowly from 400 K to 850 K. Starting with the increased mass flow of CO\({}_{2}\) the weight loss increased significantly (850 K to 1050 K). At temperatures higher than 1050 K, the mass of the sample did not change. The DSC-signal (Figure 5, blue line) showed amplitudes at 400 K and 1000 K, which were associated with the detected peaks of the mass flows of H\({}_{2}\)O (400 K) and CO\({}_{2}\) (1000 K). The results of the Rietveld analysis and the DSC-TG measurements of the raw material for the content of carbonate were in good agreement (Rietveld: 5%; DSC-TG: 4%). DSC-TG/MS/IR measurements on the carbonated wollastonite, shown exemplarily in Figure 6, were performed. During the measurement, the sample lost 25.4% of its weight. 23.9% were associated with CO\({}_{2}\), which resulted in original content of 54.8 wt % carbonate in the sample (Figure 6, Equation (2)). At approximately 400 K the mass spectrometer detected a peak of the mass flow of H\({}_{2}\)O (Figure 6, green line). The mass flow decreased rapidly until 500 K was reached. From 500 K to 750 K the mass flow of H\({}_{2}\)O rose again and held a plateau until 950 K. The IR analysis did also confirm the investigation of the releasing behavior of H\({}_{2}\)O from CaCO\({}_{3}\). The mass flow of H\({}_{2}\)O decreased significantly at temperatures higher than 950 K. The detection of the mass flow of CO\({}_{2}\) (Figure 6, magenta line) started at 800 K and increased slightly until 950 K was reached, then it formed a sharp peak until 1100 K was reached. At temperatures higher than 1100 K, the mass flow of CO\({}_{2}\) was nearly zero. The measured weight loss (Figure 6, black line) decreased slowly until 900 K. Starting with the increase of the mass flow of CO\({}_{2}\) the weight loss increased significantly (900 K to 1100 K). At temperatures higher than 1100 K, the mass of the sample did not change. The DSC-signal (Figure 6, blue line) showed a negative (endothermic) amplitude at 1100 K which was associated with the detected peak of the mass flow of CO\({}_{2}\). At 1150 K the DSC-signal showed a positive amplitude, which could be ascribed to the formation  
Figure 5: Result of the differential scanning calorimetry with thermogravimetry coupled with a mass spectrometer (DSC-TG/MS) measurement of wollastonite raw material (initial weight 20.3 mg). Measurement from 296 K to 1273 K with heating rate of 10 K/min.