The effects of transformation of slag composition and additive agents on the morphology, the precipitation behavior, the crystal growth, and the volume fraction (VF) of perovskite (CaO·¤TiO_2) crystal in the...The effects of transformation of slag composition and additive agents on the morphology, the precipitation behavior, the crystal growth, and the volume fraction (VF) of perovskite (CaO·¤TiO_2) crystal in the Ti-bearing blast furnace slags were investigated. As the morphology of perovskite is dispersed in molten slags, the crystal growth mechanism of the melting of fine dendrites and the coarsening of large grains exist throughout the solidification of molten slags. With the increase of CaO and Fe_2O_3 content, VF of perovskite obviously increases. However, high basicity leads to the viscosity of slag, which results in the reduction of the average equivalent diameter (AED). The experimental results showed that the presence of the additives CaF_2 and MnO efficiently decreased the viscosity of the slags, and obviously improved the morphology of perovskite and promoted its growth.展开更多
In the present study, the Ti-in-biotite geother- mometer was revised using more than 300 natural rutile- or ilmenite-bearing metapelites collected worldwide. The formulation was empirically calibrated as ln[T（℃）]= ...In the present study, the Ti-in-biotite geother- mometer was revised using more than 300 natural rutile- or ilmenite-bearing metapelites collected worldwide. The formulation was empirically calibrated as ln[T（℃）]= 6.313 ＋0.22 41n（XTi ） -0.2881n（XFe ） -0. 4491n（XMg） ＋ 0.15P （GPa）, with Xj=j/（Fe＋Mg＋Al^Ⅵ＋Ti） in biotite, assuming ferric iron content of 11.6 mol% of the total iron in biotite. This thermometer is consistent with the well-calibrated garnet-biotite thermometer within error of i50 ℃ for most of the calibrant samples and can successfully distin- guish systematic temperature changes of different meta- morphic zones in both prograde and inverted metamorphic terranes as well as thermal contact aureoles. Thus, the thermometer truthfully reflects real geologic conditions and can be applied to TiO2-saturated metapelites metamor- phosed at the crustal level within the calibration ranges （450-840 ℃, 0.1-1.9 GPa, XTi = 0.02-0.14 in biotite）.展开更多
基金supported by the National Natural Science Foundation of China(No.50234040).
文摘The effects of transformation of slag composition and additive agents on the morphology, the precipitation behavior, the crystal growth, and the volume fraction (VF) of perovskite (CaO·¤TiO_2) crystal in the Ti-bearing blast furnace slags were investigated. As the morphology of perovskite is dispersed in molten slags, the crystal growth mechanism of the melting of fine dendrites and the coarsening of large grains exist throughout the solidification of molten slags. With the increase of CaO and Fe_2O_3 content, VF of perovskite obviously increases. However, high basicity leads to the viscosity of slag, which results in the reduction of the average equivalent diameter (AED). The experimental results showed that the presence of the additives CaF_2 and MnO efficiently decreased the viscosity of the slags, and obviously improved the morphology of perovskite and promoted its growth.
基金supported by the National Natural Science Foundation of China(41225007)
文摘In the present study, the Ti-in-biotite geother- mometer was revised using more than 300 natural rutile- or ilmenite-bearing metapelites collected worldwide. The formulation was empirically calibrated as ln[T（℃）]= 6.313 ＋0.22 41n（XTi ） -0.2881n（XFe ） -0. 4491n（XMg） ＋ 0.15P （GPa）, with Xj=j/（Fe＋Mg＋Al^Ⅵ＋Ti） in biotite, assuming ferric iron content of 11.6 mol% of the total iron in biotite. This thermometer is consistent with the well-calibrated garnet-biotite thermometer within error of i50 ℃ for most of the calibrant samples and can successfully distin- guish systematic temperature changes of different meta- morphic zones in both prograde and inverted metamorphic terranes as well as thermal contact aureoles. Thus, the thermometer truthfully reflects real geologic conditions and can be applied to TiO2-saturated metapelites metamor- phosed at the crustal level within the calibration ranges （450-840 ℃, 0.1-1.9 GPa, XTi = 0.02-0.14 in biotite）.
