EP0996590A1 - Process for production of monohydrate alumina from supersaturated aluminate solutions - Google Patents
Process for production of monohydrate alumina from supersaturated aluminate solutionsInfo
- Publication number
- EP0996590A1 EP0996590A1 EP98925868A EP98925868A EP0996590A1 EP 0996590 A1 EP0996590 A1 EP 0996590A1 EP 98925868 A EP98925868 A EP 98925868A EP 98925868 A EP98925868 A EP 98925868A EP 0996590 A1 EP0996590 A1 EP 0996590A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- boehmite
- precipitation
- alumina
- monohydrate alumina
- sodium aluminate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/04—Preparation of alkali metal aluminates; Aluminium oxide or hydroxide therefrom
- C01F7/14—Aluminium oxide or hydroxide from alkali metal aluminates
- C01F7/144—Aluminium oxide or hydroxide from alkali metal aluminates from aqueous aluminate solutions by precipitation due to cooling, e.g. as part of the Bayer process
Definitions
- the current invention is referred to a new aluminium precipitation process from supersaturated aluminate solutions at temperatures lower than 100°C in which aluminium is precipitated with the form of monohydrate alumina (Al 2 O 3 .H 2 O).
- Bayer process is used almost exclusively for the extraction of alumina from bauxites.
- the essential steps of the Bayer process are:
- Precipitation of aluminum hydroxide (gibbsite, AJ O 3 .3H 2 O) from the pregnant liquor according to the following equation. Precipitation is effected by cooling the solution to 55 - 60°C, thus causing supersaturation, and by introducing small gibbsite particles as seeds.
- Al 2 O 3 .3H 2 O ( .) Al2 ⁇ 3(s , + 3H 2 O
- the new process which is analytically described in the current invention, is a highly innovative variation of the Bayer process whereby, at the precipitation step, alumina monohydrate (Al 2 O 3 H 2 O) rather than t ⁇ hydrate is precipitated at atmospheric conditions
- alumina monohydrate Al 2 O 3 H 2 O
- the mam feature of this method is the production of a material needed substantially lower amounts of energy during the calcination stage
- the technical characteristics of the new process are the following
- Alumina concentration in supersaturated aluminate solution is varied, typically but not exclusively, in the region 60-250g/l
- the initial seed ratio (SR), grams of added boehmite/grams of dissolved alumina, is varied, typically but not exclusively, in the region 0-5
- the precipitation of the monohydrate alumina can be carried out with or without glycerol or any other alcohol addition at concentration varied, typically but not exclusively in the region
- the aluminate solution is similar to the one that is used by the Bayer process
- concentrations of Al 2 O ⁇ , and Na 2 O are 132g/l and 120g/l respectively
- the precipitate was mineralogicaly characterized as pure monohydrate alumina (boehmite)
- the concentrations of Al 2 O and Na 2 O in the aluminate solution are 99g/l and 90g/l respectively Monohydrate alumina (boehmite) seeds are added in the solution with a ratio of 1,76 The resulting pulp is mantained by mechanical agitation at 300min " ' for 96 hours During the test, systematic sampling is carried out and the samples are analysed for Al O 3 The results of this test are given in Table 2
- the concentrations of Al 2 O 3 and Na 2 O in the aluminate solution are l lOg/l and lOOg/l respectively
- the precipitate was mineralogicaly characterized as pure monohydrate alumina (boehmite)
- Example 4 A detailed example concerning the application of the process at starting temperature near but always under 100°C is the following
- the concentrations of Al 2 O 3 and Na 2 O in the aluminate solution are 132g/l and 120g/l respectively
- Monohydrate alumina (boehmite) seeds are added in the solution with a ratio of 1,76
- the resulting pulp is mantained by mechanical agitation at 300min " ' for 96 hours at 95°C
- the temperature of the pulp is lowered by 10°C, every 24 hours, until the final value of 60°C
- the precipitate was mineralogicaly characterized as pure monohydrate alumina (boehmite)
- the concentrations of Al 2 O 3 and Na 2 O in the aluminate solution are 179g/l and 160g/l respectively
- the precipitate was mineralogicaly characterized as pure monohydrate alumina (boehmite)
- the concentrations of Al 2 O, and Na 2 O in the aluminate solution are 179g/l and I60g/l respectively Glycerol is also added at concentration of 0,9mole/kg of monohydrate alumina
- Monohydrate alumina (boehmite) seeds are added in the solution with a ratio of 2, 10
- the resulting pulp is mantained by mechanical agitation at 300min " ' for 48 hours at 90°C
- the precipitate was mineralogicaly characterized as pure monohydrate alumina (boehmite)
- the precipitate was mineralogicaly characterized as pure monohydrate alumina (boehmite)
- the above method comprises a highly innovative variation of the precipitation step in the current Bayer process It has a lot of advantages, the most important of them is the significant energy savings during the calcination stage for the following reasons
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GR97100253 | 1997-06-24 | ||
GR97100253 | 1997-06-24 | ||
PCT/GR1998/000019 WO1998058876A1 (en) | 1997-06-24 | 1998-06-23 | Process for production of monohydrate alumina from supersaturated aluminate solutions |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0996590A1 true EP0996590A1 (en) | 2000-05-03 |
Family
ID=10943016
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP98925868A Ceased EP0996590A1 (en) | 1997-06-24 | 1998-06-23 | Process for production of monohydrate alumina from supersaturated aluminate solutions |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP0996590A1 (en) |
AU (1) | AU7783398A (en) |
CA (1) | CA2294478A1 (en) |
GR (1) | GR1002926B (en) |
WO (1) | WO1998058876A1 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008116259A1 (en) * | 2007-03-27 | 2008-10-02 | Alcoa Of Australia Limited | Method for precipitating boehmite |
WO2009039592A1 (en) * | 2007-09-28 | 2009-04-02 | Alcoa Of Australia Limited | Method for precipitating boehmite from pre-precipitation bayer liquors |
CN111032829B (en) | 2017-09-07 | 2022-03-22 | 株式会社艾迪科 | Composition and flame-retardant resin composition |
CN116040667A (en) * | 2023-02-22 | 2023-05-02 | 中国神华能源股份有限公司哈尔乌素露天煤矿 | Micron-sized boehmite powder material and preparation method thereof |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2449650A1 (en) * | 1979-02-26 | 1980-09-19 | Rhone Poulenc Ind | PROCESS FOR THE PREPARATION OF ALUMINUM AT LEAST PARTIALLY IN THE FORM OF ULTRA-FINE BOEHMITE |
US4595581A (en) * | 1984-12-10 | 1986-06-17 | Aluminum Company Of America | Boehmite production by precipitation from sodium aluminate solution at elevated temperatures |
EP0366825A1 (en) * | 1988-11-04 | 1990-05-09 | Vereinigte Aluminium-Werke Aktiengesellschaft | Process for the preparation of fine platelike boehmite |
-
1997
- 1997-06-24 GR GR970100253A patent/GR1002926B/en not_active IP Right Cessation
-
1998
- 1998-06-23 AU AU77833/98A patent/AU7783398A/en not_active Abandoned
- 1998-06-23 EP EP98925868A patent/EP0996590A1/en not_active Ceased
- 1998-06-23 WO PCT/GR1998/000019 patent/WO1998058876A1/en not_active Application Discontinuation
- 1998-06-23 CA CA002294478A patent/CA2294478A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
See references of WO9858876A1 * |
Also Published As
Publication number | Publication date |
---|---|
GR1002926B (en) | 1998-06-16 |
CA2294478A1 (en) | 1998-12-30 |
AU7783398A (en) | 1999-01-04 |
WO1998058876A1 (en) | 1998-12-30 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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17P | Request for examination filed |
Effective date: 20000118 |
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RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: PANIAS, DIMITRIOS Owner name: PASPALIARIS, IOANNIS Owner name: KONTOPOULOU, MARIANNA Owner name: KONTOPOULOU, ELIZA Owner name: KONTOPOULOU, KONSTANTINA Owner name: UNIVERSITE LIBRE DE BRUXELLES Owner name: HELLENIC ALUMINA INDUSTRY S.A. (E.L.V.A.) Owner name: NATIONAL TECHNICAL UNIVERSITY OF ATHENS (NTUA) |
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17Q | First examination report despatched |
Effective date: 20000823 |
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RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: PANIAS, DIMITRIOS Owner name: NATIONAL TECHNICAL UNIVERSITY OF ATHENS (NTUA) Owner name: KONTOPOULOU, MARIANNA Owner name: KONTOPOULOU, ELIZA Owner name: KONTOPOULOU, KONSTANTINA Owner name: UNIVERSITE LIBRE DE BRUXELLES Owner name: HELLENIC ALUMINA INDUSTRY S.A. (E.L.V.A.) Owner name: PASPALIARIS, IOANNIS |
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GRAG | Despatch of communication of intention to grant |
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STAA | Information on the status of an ep patent application or granted ep patent |
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18R | Application refused |
Effective date: 20020609 |