Process of electrolysis and fractional crystallization for aluminum purification

Patent · Tue Oct 25 00:00:00 EDT 1983

OSTI ID:864750

Dawless, Robert K ^[1]; Bowman, Kenneth A ^[2]; Mazgaj, Robert M ^[3]; Cochran, C Norman ^[4]

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1. Monroeville, PA
2. Leechburg, PA
3. Lower Burrell, PA
4. Oakmont, PA

A method for purifying aluminum that contains impurities, the method including the step of introducing such aluminum containing impurities to a charging and melting chamber located in an electrolytic cell of the type having a porous diaphragm permeable by the electrolyte of the cell and impermeable to molten aluminum. The method includes further the steps of supplying impure aluminum from the chamber to the anode area of the cell and electrolytically transferring aluminum from the anode area to the cathode through the diaphragm while leaving impurities in the anode area, thereby purifying the aluminum introduced into the chamber. The method includes the further steps of collecting the purified aluminum at the cathode, and lowering the level of impurities concentrated in the anode area by subjecting molten aluminum and impurities in said chamber to a fractional crystallization treatment wherein eutectic-type impurities crystallize and precipitate out of the aluminum. The eutectic impurities that have crystallized are physically removed from the chamber. The aluminum in the chamber is now suited for further purification as provided in the above step of electrolytically transferring aluminum through the diaphragm.

• Research Organization: Aluminum Co of America
• DOE Contract Number: AC01-77CS40079
• Assignee: Aluminum Company of America (Pittsburgh, PA)
• Patent Number(s): US 4411747
• Application Number: 06/412,833
• OSTI ID: 864750
• Country of Publication: United States
• Language: English

Related Subjects

process
electrolysis
fractional
crystallization
aluminum
purification
method
purifying
contains
impurities
including
step
introducing
containing
charging
melting
chamber
located
electrolytic
cell
type
porous
diaphragm
permeable
electrolyte
impermeable
molten
steps
supplying
impure
anode
electrolytically
transferring
cathode
leaving
introduced
collecting
purified
lowering
level
concentrated
subjecting
treatment
eutectic-type
crystallize
precipitate
eutectic
crystallized
physically
removed
suited
provided
method including
aluminum containing
electrolytic cell
molten aluminum
chamber located
containing impurities
pure aluminum
/205/75/