硅酸盐水泥中元素含量检测方案(X射线能谱仪)

智能文字提取功能测试中

Phase percentage Application Note # EDS-06 Determination of the alite to belite ratio inPortland cement clinker usinghigh-speed mapping Portland cement is one of the basic materials in theconstruction industry. The principal component of Portlandcement is clinker. According to the cement nomenclature，clinker contains two silicate phases： Ca Sio(alite) andCa，SiO (belite)， as well as aluminate and ferrite. The aliteto belite ratio is responsible for the strength of Portlandcement in cement clinker. The ability of determining thisratio already during the burning phase is essential for theevaluation of the cement's final strength. This report shows that high-speed mapping with theXFlash@5030 Detector delivers the necessary informationfor chemical classification and image interpretation in a veryshort period of time. Methods The analysis was performed on a polished cement clinkersample embedded in a conductive matrix. The sample wasanalyzed with a Bruker QUANTAX system equipped with aliquid nitrogen free XFlash@ Detector (energy resolution of127 eV for Mn Ka). The element mappings were carried outunder the following measurement conditions： Accelerating voltage：15 kVBeam current：20nAInput count rate：150 000 cpsAcquisition time：5 minMapping resolution：600 x450 pixels Results Alite and belite consist of silicon， calcium and oxygen. Thecorresponding concentrations are shown in Table 1. Thesimilarity of the average atomic number of both phases (seeTab. 1) anticipates that the BSE image (Fig.2) will not deliverenough contrast to identify the phases to be analyzed. Thedifference between phases can be easily displayed withhigh-speed mapping. With it， the difference in silicon andcalcium concentrations can be quickly made visible even ata high image resolution (Fig.3). Tab. 1 Alite and belite percentage composition (wt.%) and averageatomic number Ca Si av. atomic number Alit 52.76 12.129 35.04 14.56 Belit 46.54 16.3 37.16 15.06 Fig.1 Spectra of both calcium silicate phases BSE image Fig. 2 BSE image of the sample section Threshold adjustments and the selection of the appropriatefilter in ESPRIT Feature， Bruker’s particle analysis solution，allow to distinguish the phase with higher silicon content(belite) and the phase with higher calcium content (alite) anddetermine the total area percentage of each of them. Tab. 2 Phase percentage of alite and belite Phase Area Alite 55.7% Belite 25.3% Unassigned 19.0% Bruker Nano GmbH Berlin · GermanyPhone +49 (30) 670990-0Fax +49 (30) 670990-30 info.bna@bruker.com Fig. 3 Overlay of Si and Ca element maps (belite： orange，alite： yellowish green) Binarized element distribution lsi 30 pm ICa Fig. 4 Binarized element distribution of silicon and calcium The phase percentages for alite and belite in this exampleare shown in Table 2. Consequently， the alite to belite ratiois 2.2. Conclusion This analysis shows that high-speed mapping withthe XFlash@ Detector is an excellent solution for a fastcharacterization of cement clinker samples regarding theiralite to belite ratio. Author Dr. Bernd Altrichter， Application Scientist EDS，Bruker Nano GmbH This analysis shows that high-speed mapping with the XFlash® Detector is an excellent solution for a fast characterization of cement clinker samples regarding theiralite to belite ratio.