In this data sheet we show that quantification results of the phases in clinker and cement are both accurate and precise, showing that the Cement edition of Aeris is a perfect tool for environmentally friendly cement production.
A major aspect of environmentally friendly cement production is the use of alternative fuels. The change from fossil fuels to alternative fuels affects kiln control. With fossil fuels kiln control is done using the free lime information in combination with the alite, belite, aluminate and ferrite concentrations in the clinker. These are typically estimated assuming stoichiometry in the kiln. With alternative fuels, however, stoichiometry between alite, belite, aluminate and ferrite may no longer be valid and yield erroneous process control. In order to guarantee a correct kiln control direct
probing of the clinker phases using X-ray diffraction is needed
A major aspect of environmentally friendly cement production is the use of alternative fuels. The change from fossil fuels to alternative fuels affects kiln control. With fossil fuels kiln control is done using the free lime information in combination with the alite, belite, aluminate and ferrite concentrations in the clinker. These are typically estimated assuming stoichiometry in the kiln. With alternative fuels, however, stoichiometry between alite, belite, aluminate and ferrite may no longer be valid and yield erroneous process control [1]. In order to guarantee a correct kiln control direct probing of the clinker phases using X-ray diffraction is needed.
Next to better kiln control X-ray diffraction can also be used for quality assurance of the final cement. The results of the (quantitative) phase analysis can be used to benchmark the cement against classification norms like EN-197 or ASTM C150 and to estimate the physical properties like strength or hardening properties even during production. The Cement edition of Aeris is the first benchtop X-ray diffractometer that is designed for process control in a cement plant. In this data sheet we show typical results of phase quantifications of clinker and cement along with the repeatability of these results.
In order to show the capabilities of the Cement edition of Aeris, clinker and CEM-I (EN-197) were analyzed. The measurement time was 10 minutes, followed by automatic phase quantification. Each sample was measured 15 times in order to judge the repeatability of the analysis chain.
When producing cements with alternative fuels, direct mineralogical probing of the clinker and cement becomes increasingly important. The Cement edition of Aeris is an easy-to-use benchtop X-ray diffractometer and the first that is automatable and fully suited for process control. In this data sheet we show that quantification results of the phases in clinker and cement analysis are both accurate and precise, showing that the Cement edition of Aeris is a perfect tool for environmentally friendly cement production.
Figure 1 shows the phase concentrations of clinker, while Figure 2 shows the phase concentrations of CEM I. The most significant difference between the two figures is the presence of the calcium sulfates in CEM I that has obviously been added to the clinker.
The information from Figure 1 is typically used for kiln control, while the information shown in Figure 2 is typically used for quality assurance by comparing the phase concentrations with the EN-197 or ASTM C150 norms. Table 1 shows the typical repeatability values of the phase quantification of clinker and CEM I. Please note the distinction that is made between the M1 and M3 polymorphs of alite. The results show a repeatability at 1σ well below 1 wt%, making the analyses well-suited for process control.
Figure 1. Phase concentrations of clinker
Figure 2. Phase concentrations of CEMII
Table 1 Repeatability at 1σ (3σ between brackets) of Clinker and CEM I (EN197-1). Same results are obtained with Type I-Type V cements of the ASTM C150 classification.
The presented results show the Cement edition of Aeris to be a fast and precise analysis tool for full mineralogical phase analysis. It is the first benchtop XRD instrument designed for demanding industrial process control requirements and is perfectly suited for process control of cement production, based on full mineralogical analysis.
