Low sintering temperature glass waste forms for sequestering radioactive iodine
US8262950B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2010 |
| Grant date | Sep 11, 2012 |
| Priority date | — |
| Expiry date | Jun 14, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2214/34
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Materials and methods of making low-sintering-temperature glass waste forms that sequester radioactive iodine in a strong and durable structure. First, the iodine is captured by an adsorbant, which forms an iodine-loaded material, e.g., AgI, AgI-zeolite, AgI-mordenite, Ag-silica aerogel, ZnI2, CuI, or Bi5O7I. Next, particles of the iodine-loaded material are mixed with powdered frits of low-sintering-temperature glasses (comprising various oxides of Si, B, Bi, Pb, and Zn), and then sintered at a relatively low temperature, ranging from 425° C. to 550° C. The sintering converts the mixed powders into a solid block of a glassy waste form, having low iodine leaching rates. The vitrified glassy waste form can contain as much as 60 wt % AgI. A preferred glass, having a sintering temperature of 500° C. (below the silver iodide sublimation temperature of 500° C.) was identified that contains oxides of boron, bismuth, and zinc, while containing essentially no lead or silicon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.