Quantitative phase analysis of Portland cement clinker samples was performed using an adaptation of the Rietveld method.The Rietveld quantitative analysis program,originally in Fortran 77 code,was significantly modifi...Quantitative phase analysis of Portland cement clinker samples was performed using an adaptation of the Rietveld method.The Rietveld quantitative analysis program,originally in Fortran 77 code,was significantly modified in visual basic code with windows 9X graph user interface,which is free from the constraint of direct utilizable memory 640 k,and can be conveniently operated under the windows environment.The Rietveld quantitative method provides numerous advantages over conventional XRD quantitative method,especially in the intensity anomalies and superposition problems.Examples of its use are given with the results from other methods.It is concluded that,at present,the Rietveld method is the most suitable one for quantitative phase analysis of Portland cement clinker.展开更多
Three kaolinite samples applied for paper coating were collected from America（KA）,Brazil（KB）,and China（KC）,respectively.Parameters such as average bond length of Si-O and Al-O（1（Si-O） and1（（Al-O）））,tetra...Three kaolinite samples applied for paper coating were collected from America（KA）,Brazil（KB）,and China（KC）,respectively.Parameters such as average bond length of Si-O and Al-O（1（Si-O） and1（（Al-O）））,tetrahedral rotation angles（α）,changes of tetrahedral flattemng angles（τ） and octahedral flattemng angles（ψ） comparative to ideal angle,particle layer thickness（T） and basal z corrugation（Δz） were analyzed by XRD and Rietveld method.The experimental results indicated that △z（KA）〉△z（KC）〉△z（KB）.KB has a regular structure and KA has a disorder structure,α（KA）〉α（KC）〉α（KB）,△τ（KA）〉△τ（KC）〉△τ（KB）,and △ψ（KA）〉△ψ（KB）〉△ψ（KC）.KA has unstable tetrahedron and octahedron.KB and KC have stable tetrahedron and octahedron,respectively.In the process of manufacture,kaolinite structure may be broken from places with unstable tetrahedron and octahedron.l（Si-O）（KA） 〉l（Si-O）（KB）〉l（Si-O）（KC） and 1（A1-O）KA〉1（A1-O）（KC）〉1（A1-O）（KB）.What only considered is the effect of bond length,KA may be most easily broken in the manufacture.Compared with bond lengths of KA and KB,Si-O,and Al-O of KB and KC may be easily broken,respectively.T（KA）展开更多
The influence of replacement level of calcined coal-series kaolin(CCK) on hydration of ordinary Portland cement(OPC) was studied by X-ray diffraction(XRD)/Rietveld method. X-ray diffraction/Rietveld method was used to...The influence of replacement level of calcined coal-series kaolin(CCK) on hydration of ordinary Portland cement(OPC) was studied by X-ray diffraction(XRD)/Rietveld method. X-ray diffraction/Rietveld method was used to quantify the crystalline phase composition of the hydrated samples. Additionally, the morphology of hydrated samples was observed by scanning electron microscopy(SEM). The results showed that, calcium hydroxide(CH), ettringite(AFt) and amorphous phase content in hydrated samples decreased as the replacement level of CCK increased, while AFm and str?tlingite increased, which was caused by the combination of dilute, physical and pozzolanic effects. The hydration of anhydrous cement phases was accelerated by physical effect but hindered by the retardation effect of CCK. The role of each effects was discussed in detail to analyze the mechanism of OPC hydration with CCK addition. The SEM images showed that the shortening of AFt at 1 day and the denser texture at 28 days was observed with CCK addition, which was caused by the physical and pozzolanic effects, respectively.展开更多
文摘Quantitative phase analysis of Portland cement clinker samples was performed using an adaptation of the Rietveld method.The Rietveld quantitative analysis program,originally in Fortran 77 code,was significantly modified in visual basic code with windows 9X graph user interface,which is free from the constraint of direct utilizable memory 640 k,and can be conveniently operated under the windows environment.The Rietveld quantitative method provides numerous advantages over conventional XRD quantitative method,especially in the intensity anomalies and superposition problems.Examples of its use are given with the results from other methods.It is concluded that,at present,the Rietveld method is the most suitable one for quantitative phase analysis of Portland cement clinker.
基金Funded by the National Natural Science Foundation of China(No.41302032)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)
文摘Three kaolinite samples applied for paper coating were collected from America（KA）,Brazil（KB）,and China（KC）,respectively.Parameters such as average bond length of Si-O and Al-O（1（Si-O） and1（（Al-O）））,tetrahedral rotation angles（α）,changes of tetrahedral flattemng angles（τ） and octahedral flattemng angles（ψ） comparative to ideal angle,particle layer thickness（T） and basal z corrugation（Δz） were analyzed by XRD and Rietveld method.The experimental results indicated that △z（KA）〉△z（KC）〉△z（KB）.KB has a regular structure and KA has a disorder structure,α（KA）〉α（KC）〉α（KB）,△τ（KA）〉△τ（KC）〉△τ（KB）,and △ψ（KA）〉△ψ（KB）〉△ψ（KC）.KA has unstable tetrahedron and octahedron.KB and KC have stable tetrahedron and octahedron,respectively.In the process of manufacture,kaolinite structure may be broken from places with unstable tetrahedron and octahedron.l（Si-O）（KA） 〉l（Si-O）（KB）〉l（Si-O）（KC） and 1（A1-O）KA〉1（A1-O）（KC）〉1（A1-O）（KB）.What only considered is the effect of bond length,KA may be most easily broken in the manufacture.Compared with bond lengths of KA and KB,Si-O,and Al-O of KB and KC may be easily broken,respectively.T（KA）
基金Funded by the Academician Workstation of Yichang Huilong Science and Technology Co.,Ltd.Association of Science and Technology of Hubei Province(No.2013]104-22)
文摘The influence of replacement level of calcined coal-series kaolin(CCK) on hydration of ordinary Portland cement(OPC) was studied by X-ray diffraction(XRD)/Rietveld method. X-ray diffraction/Rietveld method was used to quantify the crystalline phase composition of the hydrated samples. Additionally, the morphology of hydrated samples was observed by scanning electron microscopy(SEM). The results showed that, calcium hydroxide(CH), ettringite(AFt) and amorphous phase content in hydrated samples decreased as the replacement level of CCK increased, while AFm and str?tlingite increased, which was caused by the combination of dilute, physical and pozzolanic effects. The hydration of anhydrous cement phases was accelerated by physical effect but hindered by the retardation effect of CCK. The role of each effects was discussed in detail to analyze the mechanism of OPC hydration with CCK addition. The SEM images showed that the shortening of AFt at 1 day and the denser texture at 28 days was observed with CCK addition, which was caused by the physical and pozzolanic effects, respectively.
