Application of molten salts in pyrochemical processing of reactive metals

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6958745

Mishra, B; Olson, D L ^[1]; Averill, W A ^[2]

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1. Colorado School of Mines, Golden, CO (United States). Kroll Inst. for Extractive Metallurgy
2. EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant

Various mixes of chloride and fluoride salts are used as the media for conducting pyrochemical processes in the production and purification of reactive metals. These processes generate a significant amount of contaminated waste that has to be treated for recycling or disposal. Molten calcium chloride based salt systems have been used in this work to electrolytically regenerate calcium metal from calcium oxide for the in situ reduction of reactive metal oxides. The recovery of calcium is characterized by the process efficiency to overcome back reactions in the electrowinning cell. A thermodynamic analysis, based on fundamental rate theory, has been performed to understand the process parameters controlling the metal deposition, rate, behavior of the ceramic anode-sheath and influence of the back-reactions. It has been observed that the deposition of calcium is dependent on the ionic diffusion through the sheath. It has also been evidenced that the recovered calcium is completely lost through the back-reactions in the absence of a sheath. A practical scenario has also been presented where the electrowon metal can be used in situ as a reductant to reduce another reactive metal oxide.

• Research Organization: EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC34-90DP62349
• OSTI ID: 6958745
• Report Number(s): RFP-4610; CONF-930219--1; ON: DE92018618
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400 -- Electrochemistry
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
CALCIUM
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
DEPOSITION
ELECTRODEPOSITION
ELECTROLYSIS
ELECTROMETALLURGY
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
LYSIS
METALLURGY
METALS
MOLTEN SALTS
OXIDES
OXYGEN COMPOUNDS
REDUCTION
REGENERATION
SALTS
SURFACE COATING
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
THERMODYNAMICS