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gtjtp100(金币+3, 翻译EPI+1): 2010-08-21 23:21:23
Known from the Table 3, the table is divided into four groups A, B, C, D represent the aging temperature is 50 ℃, 60 ℃, 70 ℃, 80 ℃ aging time when the basic magnesium carbonate formation on the impact of its shape experimental conditions. (In the A group), at 50 ℃ aging 1-15 hours after the needle-like white precipitation generated by the XRD analysis of this substance may MgCO3 • 3H2O. (In the B group), at 60 ℃ for 1-12 hours after the aging, white matter are generated by the optical microscope that are needle-like, but determined by the XRD analysis showed that after 1-6 hours of aging formed for MgCO3 • 3H2O; aging 7-12 hours after the formation of the material for the MgCO3 • 3H2O and 4MgCO3 • Mg (OH) 2 • 5H2O. At 60 ℃, aging time more than 12 hours after the resulting white needle-like material substances, determined by XRD analysis and found it 4MgCO3 • Mg (OH) 2 • 5H2O.
(In the C group), aging at 70 ℃ 1 hour after the resultant through optical microscope observation and XRD analysis to determine the 3MgCO3 • 3H2O; when the aging 2-3 hours, the resulting material was MgCO3 • 3H2O and 4MgCO3 • Mg (OH) 2 • 4H2O mixture, and its crystals are needle-like shape; and when the aging time is more than 4 hours, the generation of material for the needle 4MgCO3 • Mg (OH) 2 • 4H2O.
(In the D group), aging at 80 ℃, 0.5 hours, the resulting material is spherical MgCO3 • 3H2O; when the aging 0. 5-1 hours later, the resulting material is spherical MgCO3 • 3H2O and 4MgCO3 • Mg (OH) 2 • 4H2O in the mixture; with aging time (more than 1 hour), the resulting material 4MgCO3 • Mg (OH ) 2 • 4H2O.
Comparison of four groups, we found that with the aging temperature, aging time required to reduce. At the same time when the aging temperature is below 70 ℃, are needle-like material generated, but the aging temperature to 80 ℃, the resulting material was spherical. This is because when the temperature is too low, the formation of nuclei than the grain growth rate faster. As the temperature increases, the growth rate were both increased, but the grain growth rate faster than the formation of nuclei. |
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