Preparation of powders suitable for conversion to useful .beta.-aluminas
- Thousand Oaks, CA
A process for forming a precursor powder which, when suitably pressed and sintered forms highly pure, densified .beta.- or .beta."-alumina, comprising the steps of: (1) forming a suspension (or slurry) of Bayer-derived Al(OH).sub.3 in a water-miscible solvent; (2) adding an aqueous solution of a Mg compound, a Li compound, a Na compound or mixtures thereof to the Bayer-derived Al(OH).sub.3 suspension while agitating the mixture formed thereby, to produce a gel; (3) drying the gel at a temperature above the normal boiling point of water to produce a powder material; (4) lightly ball milling and sieving said powder material; and (5) heating the ball-milled and sieved powder material at a temperature of between 350.degree. to 900.degree. C. to form the .beta.- or .beta."-alumina precursor powder. The precursor powder, thus formed, may be subsequently isopressed at a high pressure and sintered at an elevated temperature to produce .beta.- or .beta."-alumina. BACKGROUND OF THE INVENTION
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Number(s):
- US 4339511
- OSTI ID:
- 864268
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
-aluminas
/264/429/501/
350
900
adding
agitating
aqueous
aqueous solution
background
ball
ball-milled
bayer-derived
beta
boiling
compound
comprising
conversion
degree
densified
drying
elevated
elevated temperature
form
formed
forming
forms
heating
highly
highly pure
isopressed
lightly
material
mg
milling
mixture
mixtures
na
normal
oh
powder
powder material
powders
precursor
precursor powder
preparation
pressed
pressure
process
produce
pure
sieved
sieving
sintered
slurry
solution
solvent
steps
subsequently
suitable
suitably
suspension
temperature
useful
water
water-miscible