Amphoteric behavior of alumina in viscous flow and structure of CaO-SiO2 (-MgO)-Al2O3 slags
Amphoteric behavior of alumina in viscous flow and structure of CaO-SiO2 (-MgO)-Al2O3 slags
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DOI：
10.1007/s11663-004-0028-2
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发表时间：
2004-04-01
影响因子：
3
通讯作者：
Song, HS
中科院分区：
文献类型：
--
作者：
Park, JH;Min, DJ;Song, HS
为了研究Al_2O_3和MgO对高温熔渣结构和粘性流动的影响，测定了CaO-SiO_2（-MgO）-Al_2O_3渣系的粘度。此外，对急冷渣的红外光谱进行了分析，以了解Al 2 O3在硅酸盐网络聚合或解聚中的结构作用。Al 2 O3是一种两性氧化物。炉渣成分;也就是说，氧化铝在高达约10质量% Al 2 O 3时作为网络形成剂，而在大于10质量% Al 2 O 3的组合物中，氧化铝部分地作为网络改性剂。这种两性作用的Al 2 O3在熔渣的粘性流动在牛顿流区减弱的MgO的共存。Al 2 O3对粘度增加的影响可以基于通过将[AlO 4]-四面体引入[SiO 4]-四面体单元而增加的聚合度（DOP）来理解，并且这通过急冷炉渣的红外（IR）光谱来证实。氧化铝对粘度降低的影响可以解释的基础上减少的DOP的[AlO 6]-八面体单元的相对分数的增加。具有低NBO/Si的[SiO 4] -四面体的IR带的相对强度降低，而具有高NBO/Si的[SiO 4] -四面体的IR带的相对强度随着Al 2 O3含量的增加而增加，大于临界点，即，大约10质量。在目前的系统中。熔渣组分活度系数随组成的变化间接支持了熔体粘度和结构的变化。
The viscosity of CaO-SiO2 (-MgO)-Al2O3 slags was measured to clarify the effects of Al2O3 and MgO on the structure and viscous flow of molten slags at high temperatures. Furthermore, the infrared spectra of the quenched slags were analyzed to understand the structural role of Al2O3 in the polymerization or depolymerization of silicate network. The Al2O3 behaves as an amphoteric oxide with. the composition of slags; that is, the alumina behaves as a network former up to about 10 mass pct Al2O3, while it acts as a network modifier, in parts, in the composition greater than 10 mass pct Al2O3. This amphoteric role of Al2O3 in the viscous flow of molten slags at the Newtonian flow region was diminished by the coexistence of MgO. The effect of A1203 on the viscosity increase can be understood based on an increase in the degree of polymerization (DOP) by the incorporation of the [AlO4]-tetrahedra into the [SiO4]-tetrahedral units, and this was confirmed by the infrared (IR) spectra of the quenched slags. The influence of alumina on the viscosity decrease can be explained on the basis of a decrease in the DOP by the increase in the relative fraction of the [AlO6]-octahedral units. The relative intensity of the IR bands for the [SiO4] -tetrahedra with low NBO/Si decreased, while that of the IR bands for [SiO4] -tetrahedra with high NBO/Si increased with increasing Al2O3 content greater than the critical point, i.e., about 10 mass. pct in the present systems. The variations of the activity coefficient of slag components with composition indirectly supported those of viscosity and structure of the aluminosilicate melts.