Investigation of corrosion experienced in a spray calciner/ceramic melter vitrification system

Technical Report · Fri Aug 01 04:00:00 EDT 1980

DOI:https://doi.org/10.2172/6993293· OSTI ID:6993293

Dierks, R D; Mellinger, G B; Miller, F A; Nelson, T A; Bjorklund, W J

After periodic testing of a large-scale spray calciner/ceramic melter vitrification system over a 2-yr period, sufficient corrosion was noted on various parts of the vitrification system to warrant its disassembly and inspection. A majority of the 316 SS sintered metal filters on the spray calciner were damaged by chemical corrosion and/or high temperature oxidation. Inconel-601 portions of the melter lid were attacked by chlorides and sulfates which volatilized from the molten glass. The refractory blocks, making up the walls of the melter, were attacked by the waste glass. This attack was occurring when operating temperatures were >1200/sup 0/C. The melter floor was protected by a sludge layer and showed no corrosion. Corrosion to the Inconel-690 electrodes was minimal, and no corrosion was noted in the offgas treatment system downstream of the sintered metal filters. It is believed that most of the melter corrosion occurred during one specific operating period when the melter was operated at high temperatures in an attempt to overcome glass foaming behavior. These high temperatures resulted in a significant release of volatile elements from the molten glass, and also created a situation where the glass was very fluid and convective, which increased the corrosion rate of the refractories. Specific corrosion to the calciner components cannot be proven to have occurred during a specific time period, but the mechanisms of attack were all accelerated under the high-temperature conditions that were experienced with the melter. A review of the materials of construction has been made, and it is concluded that with controlled operating conditions and better protection of some materials of construction corrosion of these systems will not cause problems. Other melter systems operating under similar strenuous conditions have shown a service life of 3 yr.

• Research Organization: Battelle Pacific Northwest Labs., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6993293
• Report Number(s): PNL-3406
• Country of Publication: United States
• Language: English

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12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALLOYS
CALCINATION
CERAMIC MELTERS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION
CORROSION RESISTANT ALLOYS
DECOMPOSITION
EQUIPMENT
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCONEL 690
INCONEL ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MANAGEMENT
MATERIALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
PHASE TRANSFORMATIONS
PROCESSING
PYROLYSIS
RADIOACTIVE WASTE PROCESSING
SOLIDIFICATION
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
THERMOCHEMICAL PROCESSES
VITRIFICATION
WASTE MANAGEMENT
WASTE PROCESSING