A Theoretical Method to Calculate the Viscosity of NaAlSi 3O 8 Melt
一种计算NaAlSi3O8熔体粘度的理论方法

It is believed that the viscosity of silicate melt dependents on the characters of its chemical composition, however, the change of melt structure is the reason for the change of viscosity. The relationship between viscosity and chemical composition, actually, is the reflection of the relationship between viscosity and melt structure. There is only Si-O bond in SiO 2 melt, and in NaAlSi 3O 8 melt exist Si-O, Al-O, and Na-O bonds. In the structure of NaAlSi 3O 8 melt, Na-O bond associated with Si, which can low the strength of Si-O bond, in the result, the Si-O bond associated with Na-O bond will be weaker than that of the separate Si-O bond, therefore, NaAlSi 3O 8 melt has a lower viscosity than SiO 2 melt. Based on this principle, we designed a model for the viscosity calculation of NaAlSi 3O 8 melt, which can give a good result for NaAlSi 3O 8 melt at suitable geological temperature.