Chemistry of inorganic compounds – Carbon or compound thereof – Oxygen containing
Patent
1990-05-08
1992-10-06
Lieberman, Paul
Chemistry of inorganic compounds
Carbon or compound thereof
Oxygen containing
423419R, 423420, 423 211, 423 35, 423158, 423165, 252518, 252521, 505 1, 505737, 505738, C01B 3124, H01L 3912
Patent
active
051529734
ABSTRACT:
The invention process provides a metal oxide, or oxides of more than one more metal, wherein the oxides have a mean particle size less than 1 micron. The oxides are made by steps including (1) reacting an aqueous solution of a metal salt (or salts) that form insoluble carbonate(s), thereby to form a carbonate precipitate, followed by (b) recovering the precipitate, e.g., by filtration; (c) redispersing the precipitate in water to form a second very dilute slurry; (d) spray-drying said second slurry; (e) calcining the spray-dried product at a low temperature (e.g., 540.degree. C.), followed by a final calcination in atmosphere consisting of flowing oxygen initially under reduced pressure (e.g., 2 Torr). The spray-dried spheroids comprise particles having a mean particle size less than one micron, a property carried over into the products of both calcinations.
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Capella Steven
Lieberman Paul
Swope Bradley A.
W. R. Grace & Co.,-Conn.
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