A crucible salt saturation method for determining sulfur solubility in glass melt

• Published in: International journal of applied glass science Vol. 10; no. 1
• Main Authors: Jin, Tongan, Kim, Dongsang, Darnell, Lori P., Weese, Brigitte L., Canfield, Nathan L., Bliss, Mary, Schweiger, Michael J., Vienna, John D., Kruger, Albert A.
• Format: Journal Article
• Language: English
• Published: United States Wiley-Blackwell 28.06.2018
• ISSN: 2041-1286; 2041-1294

Abstract Experiments were conducted to determine sulfur solubility in Hanford low‐activity waste ( <styled-content style='fixed-case'>LAW</styled-content> ) glass melts by a sulfur saturation method. Sulfur‐incorporated glass melts were prepared by salt saturation and bubbling methods. The salt saturation method was performed by mixing crushed premelted baseline glasses with an excess amount of Na 2 <styled-content style='fixed-case'>SO</styled-content> 4 prior to melting the mixture at 1150°C for 1 hour. The bubbling method involved bubbling the glass melt at 1150°C in a Pt crucible with an <styled-content style='fixed-case'>SO</styled-content> 2 /O 2 /N 2 gas mix to equilibrate the melt at a known pressure of <styled-content style='fixed-case'>SO</styled-content> 3 . Preliminary results suggested that performing 1 cycle of mixing and melting was not sufficient to saturate the glass. The bubbling method successfully incorporated sulfur into the glass but caused significant losses of sodium from the melt. In order to saturate the glass melt with sulfate without causing noticeable sodium loss, a modified crucible salt saturation method was developed by repeating the mixing and melting of the glass and salt mixture. For all 3 representative <styled-content style='fixed-case'>LAW</styled-content> glasses tested in this study, it was found that after 3 mixing and melting cycles, the sulfur concentration reaches a plateau, indicating reasonable sulfur saturation.