Application of ceramic membrane in molten salt electrolysis of CaO-CaCl{sub 2}

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Waste Management

DOI:https://doi.org/10.1016/S0956-053X(97)10051-4· OSTI ID:642258

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

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1. Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering

Calciothermic reduction of radioactive metal oxides and halides produces calcium compounds as the by-product which require subsequent processing to mitigate and control a potential source of waste generation. Attempts to recover elemental calcium by direct molten salt electrolysis of calcium compounds using carbon anodes have met with very limited success due to severe process limitations and stringent cell design requirements. A feasible process to win calcium in a modified cell is discussed where a porous anodic diaphragm has been used around the carbon anode. The effective diffusion coefficient for steady state cell operation has been estimated and is found to depend on the porosity and morphology of the anode sheath. An expression for the maximum electrowinning rate, incorporating an effective diffusion coefficient, has been developed and can be used to determine the limiting current density under steady-state conditions. The possibility of enhancing the current efficiency to an acceptable level by in situ application of calcium as a reductant is suggested.

• OSTI ID: 642258
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 7 Vol. 17; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CALCIUM
CALCIUM CHLORIDES
CALCIUM OXIDES
ELECTROLYSIS
INDUSTRIAL WASTES
MATERIALS RECOVERY
SEPARATION PROCESSES
WASTE PROCESSING