Method for dissolution and stabilization of silica-rich fibers

Patent · Wed Jan 01 04:00:00 EST 1997

OSTI ID:871224

Jantzen, Carol M ^[1]

---

1. Aiken, SC

A method for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters.

• Research Organization: WESTINGHOUSE SAVANNAH RIVER CO
• DOE Contract Number: AC09-89SR18035
• Assignee: United States Department of Energy (Washington, DC)
• Patent Number(s): US 5686365
• OSTI ID: 871224
• Country of Publication: United States
• Language: English

Related Subjects

/501/65/134/588/
48
96
acid
added
adjusting
asbestos
borosilicate
caustic
comprises
concentration
contaminated
disposal
disposing
dissolution
dissolved
dissolves
dissolving
equilibrium
fiberglass
fibers
filters
five-weight-percent
heme
hepa
hepa filter
hot
hours
hydroxide
hydroxide solution
immersing
left
method
method comprise
method comprises
nitric
nitric acid
oxide solution
ph
reaches
residue
safe
safe disposal
silica
silica-rich
silica-rich fibers
sodium
sodium hydroxide
solution
stabilization
stabilize
stream
useful
vitrification
waste