Mercury stabilization in chemically bonded phosphate ceramics

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:561198

Wagh, Arun S; Jeong, Seung-Young; Singh, Dileep

We have investigated mercury stabilization in chemically bonded phosphate ceramic (CBPC) using four surrogate waste streams that represent U.S. Department of Energy (DOE) ash, soil, and two secondary waste streams resulting from the destruction of DOE`s high-organic wastes by the DETOX{sup SM} Wet Oxidation Process. Hg content in the waste streams was 0.1 to 0.5 wt.% (added as soluble salts). Sulfidation of Hg and its concurrent stabilization in the CBPC matrix yielded highly nonleachable waste forms. The Toxicity Characteristic Leaching Procedure showed that leaching levels were well below the U.S. Environmental Protection Agency`s regulatory limits. The American Nuclear Society`s ANS 16.1 immersion test also gave very high leaching indices, indicating excellent retention of the contaminants. In particular, leaching levels of Hg in the ash waste form were below the measurement detection limit in neutral and alkaline water, negligibly low but measureable in the first 72 h of leaching in acid water, and below the detection limit after that. These studies indicate that the waste forms are stable in a wide range of chemical environments during storage. 9 refs., 5 tabs.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 561198
• Report Number(s): ANL/ET/CP--93971; CONF-9610115--; ON: DE97053851
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
ASHES
CERAMICS
LEACHING
LOW-LEVEL RADIOACTIVE WASTES
MERCURY
PHOSPHATES
RADIOACTIVE WASTE PROCESSING
SOILS
SOLIDIFICATION
SULFIDATION
WASTE FORMS
WET OXIDATION PROCESSES