Process for treating alkaline wastes for vitrification

Patent · Sun Jan 01 00:00:00 EST 1995

OSTI ID:869999

Hsu, Chia-lin W ^[1]

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1. Augusta, GA

A process for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO.sub.2 to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO.sub.2, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States)
• DOE Contract Number: AC09-89SR18035
• Assignee: United States Department of Energy (Washington, DC)
• Patent Number(s): US 5435942
• OSTI ID: 869999
• Country of Publication: United States
• Language: English

Related Subjects

process
treating
alkaline
wastes
vitrification
involves
acidifying
oxidizing
agent
nitric
acid
adding
formic
reducing
mixing
glass
formers
produce
melter
feed
contributes
nitrates
oxidant
balance
redox
prevent
reduction
species
conducting
metals
ph
suitable
level
operation
reduces
mercury
compounds
elemental
removal
steam
stripping
mno
mn
ii
foaming
melt
optimum
amounts
determined
relation
composition
including
concentrations
noble
metal
formates
forth
minimizes
amount
hydrogen
generated
treatment
producing
redox-balanced
effective
quality
product
glass former
alkaline waste
mercury compounds
metal compound
process involves
metal compounds
nitric acid
noble metal
reducing agent
oxidizing agent
glass melt
glass formers
formic acid
elemental mercury
melter operation
quality glass
glass product
steam stripping
treating alkaline
oxidizing agen
treating alkali
alkaline wastes
conducting metal
/252/210/588/