Melt viscosities in the system Na-Fe-Si-O-F-Cl: Contrasting effects of F and Cl in alkaline melts
Melt viscosities in the system Na-Fe-Si-O-F-Cl: Contrasting effects of F and Cl in alkaline melts
复制标题
Na-Fe-Si-O-F-Cl 体系中的熔体粘度：F 和 Cl 在碱性熔体中的对比效果
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
K. Hess
中科院分区：
文献类型：
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作者：
Donald Bruce Dingwell;K. Hess
摘要 Na-Fe-Si-O-F-Cl 体系中熔体的剪切粘度是在空气中、1 atm 压力下、在很宽的温度范围（400-1200 °C）下测定的。该组合物基于将 Fe2O3、FeCl3 和 FeF3 添加到相当于二硅酸钠 (Na2Si2O5) 的基础熔体组合物中。使用同心圆柱体和微渗透方法测定粘度，测量范围为 100.5 至 1011 Pa·s。在粘度测定后分析这些熔体的化学成分。在粘度测定条件下铁被完全氧化。尽管 F，尤其是 Cl 是硅酸盐熔体中的挥发性元素，但在这些熔体中 Cl 和 F 的含量分别高达 3 wt% 和 4 wt% 以上，可能是由于 Fe3+ 的存在而得以稳定。尽管在这些样品的最初合成过程中发生了一些挥发，但在粘度测定过程中没有发生。阴离子取代Cl2O-1和F2O-1对粘度的影响截然不同。 F2O-1 取代导致在整个研究范围内粘度急剧下降，而 Cl2O-1 取代导致高粘度范围内的粘度下降小得多，而低粘度范围内的粘度略有增加。因此，强过碱性欠饱和火山岩中 Cl 的次要到主要元素丰度不太可能显着影响熔体粘度。
Abstract The shear viscosities of melts in the system Na-Fe-Si-O-F-Cl were determined over a wide range of temperatures (400-1200 °C) at 1 atm pressure in air. The compositions are based on the addition of Fe2O3, FeCl3, and FeF3 to a base melt composition corresponding to sodium disilicate (Na2Si2O5). Viscosities were determined using concentric cylinder and micropenetration methods and measurements span the range of 100.5 to 1011 Pa·s. The chemical compositions of these melts were analyzed after the viscometry determinations. The iron is fully oxidized under the conditions of the viscometry. Although F and especially Cl are volatile elements in silicate melts, levels of Cl and F up to over 3 and 4 wt%, respectively, were stabilized in these melts, assisted presumably by the presence of Fe3+. Although some volatilization occurred during the original synthesis of these samples, none occurred during viscometry. The anionic substitutions Cl2O-1 and F2O-1 have very different influences on the viscosity. The F2O-1 substitution causes a drastic decrease in viscosity over the entire investigated range whereas the Cl2O-1 substitution causes a much smaller decrease in viscosity in the high viscosity range and a slight increase in viscosity in the low viscosity range. As a consequence, minor to major element abundance of Cl in strongly peralkaline undersaturated volcanic rocks are not likely to significantly influence melt viscosity.