Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
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Chemical zoning of calcium aluminoferrite formed during melt crystallization in CaO-SiO2-Al2O3-Fe 2O3 pseudoquaternary system
In the CaO-SiO2-Al2O3-Fe2O 3 pseudoquaternary system, the solid solutions of Ca 2(AlxFe1-x)2O5, with x<0.7 (ferrite), Ca2SiO4 (belite), Ca 3Al2O 6 (C3A) and Ca 12Al14O33 (C12A7), were crystallized out of a complete melt during cooling at 8.3 degree C/min. Upon cooling to 1370 degree C, both the crystals of ferrite with x=0.41 and belite would start to nucleate from the melt. During further cooling, the x value of the precipitating ferrite would progressively increase and eventually approach 0.7. At ambient temperature, the ferrite crystals had a zonal structure, the x value of which successively increased from the cores toward the rims. The value of 0.45 was confirmed for the cores by EPMA. The chemical formula of the rims was determined to be Ca2.03(Al1.27Fe0.68Si 0.02) Sigma 1.97O5 (x=0.65). As the crystallization of ferrite and belite proceeded, the coexisting melt would become progressively enriched in the aluminate components. After the termination of the ferrite crystallization, the C3A and belite would immediately crystallize out of the melt, followed by the nucleation of C12A 7. The C12A7 accommodated about 2.1 mass% Fe2O3 in the chemical formula Ca12.03(Al 13.61Fe0.37)Sigma 13.98O33, being free from the other foreign oxides (SiO 2 and P2O 5).
Chemical zoning of calcium aluminoferrite formed during melt crystallization in CaO-SiO2-Al2O3-Fe 2O3 pseudoquaternary system
In the CaO-SiO2-Al2O3-Fe2O 3 pseudoquaternary system, the solid solutions of Ca 2(AlxFe1-x)2O5, with x<0.7 (ferrite), Ca2SiO4 (belite), Ca 3Al2O 6 (C3A) and Ca 12Al14O33 (C12A7), were crystallized out of a complete melt during cooling at 8.3 degree C/min. Upon cooling to 1370 degree C, both the crystals of ferrite with x=0.41 and belite would start to nucleate from the melt. During further cooling, the x value of the precipitating ferrite would progressively increase and eventually approach 0.7. At ambient temperature, the ferrite crystals had a zonal structure, the x value of which successively increased from the cores toward the rims. The value of 0.45 was confirmed for the cores by EPMA. The chemical formula of the rims was determined to be Ca2.03(Al1.27Fe0.68Si 0.02) Sigma 1.97O5 (x=0.65). As the crystallization of ferrite and belite proceeded, the coexisting melt would become progressively enriched in the aluminate components. After the termination of the ferrite crystallization, the C3A and belite would immediately crystallize out of the melt, followed by the nucleation of C12A 7. The C12A7 accommodated about 2.1 mass% Fe2O3 in the chemical formula Ca12.03(Al 13.61Fe0.37)Sigma 13.98O33, being free from the other foreign oxides (SiO 2 and P2O 5).
Chemical zoning of calcium aluminoferrite formed during melt crystallization in CaO-SiO2-Al2O3-Fe 2O3 pseudoquaternary system
Fukuda, Koichiro (Autor:in) / Bessho, Takahiro (Autor:in) / Matsunaga, Kenichi (Autor:in) / Yoshida, Hideto (Autor:in)
Cement and Concrete Research ; 34 ; 1535-1540
2004
6 Seiten, 5 Quellen
Aufsatz (Zeitschrift)
Englisch
| British Library Online Contents | 2004
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