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The effect of chlorine on the viscosity of Na 2 OFe 2 O 3-Al 2 O 3-SiO 2 melts
| Content Provider | Semantic Scholar |
|---|---|
| Author | Zimova, Milada Webb, Sharon |
| Copyright Year | 2006 |
| Abstract | The shear viscosities of Cl-bearing melts in the system Na2O-Fe2O3-Al2O3-SiO2 were determined at temperatures of 550950 °C in the range of 10 to 10 Pa s using the micropenetration technique. The compositions are based on addition of Fe2O3 or FeCl3 to aluminosilicate glasses with a Þ xed amount of SiO2 (67 mol%). Although there was loss of Cl during the glass syntheses, no loss occurred during the viscometry experiments. It is to be expected that Cl takes the structural position of O, and thus reduces the polymerization of the melt structure, and therefore the viscosity of the melt; as F does. Our measurements show that the presence of Cl increases or decreases the viscosity of the melts as a function of melt composition. In the present melts, at least 10% of the Fe exists as network-modifying or charge-balancing Fe; whereas the rest exists as network-forming Fe. It is proposed here that the different effects of Cl on viscosity are due to the preferred Cl-FeNBO bonding together with the different structure of peralkaline and peraluminous melts. In peralkaline aluminosilicate melts, the addition of Cl2O-1 will destroy 2 NBOs and create one BO if Cl bonds primarily to the Fe creating non-bridging O atoms. This would result in an increase in viscosity. In peraluminous melts, the addition of Cl2O1 may result in Cl bonds to the charge-balancing Fe, creating 2 new tri-clusters [assuming (Al,Fe)Si2O5 tri-clusters exist]. The preference of Cl to form bonds to the NBO-forming Fe is indicated by the small amount of Cl soluble in the peraluminous melt structure in comparison to that soluble in the peralkaline structure. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.minsocam.org/msa/AmMin/TOC/Abstracts/2006_Abstracts/FM06_Abstracts/Zimova_p344_06.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
