Chemistry of inorganic compounds – Oxygen or compound thereof – Metal containing
Patent
1991-11-27
1994-02-15
Lewis, Michael
Chemistry of inorganic compounds
Oxygen or compound thereof
Metal containing
16510416, C01F 702
Patent
active
052864723
ABSTRACT:
A process for producing alumina is described in which the efficiency of calcination is greatly improved by utilizing a total heat exchange system in which alumina hydrate is heated stepwise in a plurality of heat exchange stages to sequentially higher temperatures approaching calcining temperatures and is then fed to a calciner for final conversion to alumina, and the calcined alumina is cooled in a plurality of heat exchange stages, with sensible heat being transferred from the calcined alumina cooling stages to the alumina hydrate heating stages at a temperature in each stage only slightly higher than the temperature of a heating stage or at which the heat is consumed in that stage. Further efficiency in the system may be obtained by predrying the alumina hydrate to remove superficial moisture using air from the system. Furthermore, exhaust gases from the calciner may be used to preheat combustion and fluidizing air for the calciner.
REFERENCES:
patent: 2715018 (1955-08-01), Lapple et al.
patent: 2715548 (1955-08-01), Fish
patent: 2919905 (1960-01-01), Bayard
patent: 3156538 (1964-11-01), Schneider
patent: 3307921 (1967-03-01), Junginger
patent: 3336109 (1967-08-01), du Bellay et al.
patent: 3529356 (1970-09-01), Diettrich
patent: 3565408 (1971-02-01), Reh et al.
patent: 3579294 (1971-05-01), Tamise et al.
patent: 4158036 (1979-06-01), Jaffe et al.
patent: 4224288 (1980-09-01), Potter
patent: 4250774 (1981-02-01), Kraxner et al.
patent: 4352660 (1982-10-01), Steiner et al.
patent: 4476816 (1984-10-01), Cannon et al.
patent: 4499944 (1985-02-01), Komakine
patent: 4529579 (1985-07-01), Raahauge
patent: 4585645 (1986-04-01), Sucech
patent: 4746492 (1988-05-01), Marlair
Dunn et al, "Heat Pipes", Permagon Press, 1976, pp. 1-7, 236-237, 248-250.
John C. Olsen, "Unit processes and principles of Chemical Engineering", Chapter 1, pp. 1-3.
Webster's Third New International Dictionary, G. & E. Merriam Co., 1976, pp. 2126 & 2374.
Kern, "Process Heat Transfer", 1950, pp. 484-487, 866, 869.
Alcan International Limited
Lewis Michael
Nguyen N. M.
LandOfFree
High efficiency process for producing high purity alumina does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High efficiency process for producing high purity alumina, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High efficiency process for producing high purity alumina will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1204939