US4048285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the extraction of alumina from minerals, rocks and industrial by-products
Assignee: CHEMOKOMPLEX VEGYIPARI GEP-ES BERENDEZES EXPORT-IMPORT VALLALAT
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Filing: 1976-09-30
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Granted: 1977-09-13
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Expires: 1996-09-30
Abstract
Abstract The invention concerns a process for solubilizing alumina in minerals, rocks or industrial waste products, in which the starting material in finely divided form is mixed with lime in an amount 1 to 3 moles or more of lime (CaO or Ca(OH) 2 ) for each mole of alumina and optionally 1 mole for each mole of any silica present in the starting material, and at the same time or thereafter with water, the resulting mix is maintained under hydrothermal conditions until the alumina has become solubilized by reaction with the lime, and the product is if necessary comminuted to bring it to a form suitable for leaching out of the solubilized alumina.
Inventors
- 👤 Karoly Szepesi
- 👤 Lajos Meszaros
- 👤 Janos Majer
- 👤 Jozsef Zoldi
- 👤 Karl Entzmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:46
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/16; C01F7/18; B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/12; C01D; C01D1/00; C01F7/04; C01F7/12; C01F7/164; C05; C05C; C05C1/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
138 words
A process for recovering alumina present in an alumina-bearing material selected from the group consisting of minerals, rocks, and industrial waste products derived from such minerals or rocks comprising the steps of: a. kneading particles of said alumina-bearing materials with lime and water to form a homogeneous plastic mass, said lime being present in an amount of 1 to 3 moles per mole of alumina in said alumina-bearing material; b. forming said homogeneous plastic mass into a plurality of shaped bodies; c. maintaining said shaped bodies under hydrothermal conditions at a temperature of up to 200° C for a time sufficient for the bodies to harden by hydraulic setting and to solubilize the alumina in the bodies by reaction with said lime; d. comminuting the hardened bodies; and e. leaching the solubilized alumina from the comminuted hardened bodies.
Claim 2
Dependent Claim
138 words
A process for recovering alumina present in an alumina-bearing material selected from the group consisting of minerals, rocks, and industrial waste products derived from such minerals or rocks comprising the steps of: a. kneading particles of said alumina-bearing materials with lime and water to form a homogeneous plastic mass, said lime being present in an amount of 1 to 3 moles per mole of alumina in said alumina-bearing material; b. forming said homogeneous plastic mass into a plurality of shaped bodies; c. maintaining said shaped bodies under hydrothermal conditions at a temperature of up to 200° C for a time sufficient for the bodies to harden by hydraulic setting and to solubilize the alumina in the bodies by reaction with said lime; d. comminuting the hardened bodies; and e. leaching the solubilized alumina from the comminuted hardened bodies.
Claim 3
Dependent Claim
34 words
A process according to claim 1 wherein said alumina-bearing material additionally bears silica and wherein additional lime is present in an amount of about 1 mole per mole of silica in said alumina-bearing material.
Claim 4
Dependent Claim
21 words
A process according to claim 2 wherein said shaped bodies are maintained under said hydrothermal conditions at a pressure above atmospheric.
Claim 5
Dependent Claim
19 words
A process according to claim 2 wherein said shaped bodies are maintained under said hydrothermal conditions at atmospheric pressure.
Claim 6
Dependent Claim
21 words
A process according to claim 1 wherein said comminuted hardened bodies have a particle size of from 60 to 3000 microns.
Claim 7
Dependent Claim
27 words
A process according to claim 1 wherein said alumina-bearing material comprises red mud and wherein solibilized alumina is leached from said comminuted hardened bodies with boiling water.
Claim 8
Dependent Claim
43 words
A process according to claim 1 wherein the amount of said lime is from 2 to 3 moles per mole of alumina in said alumina-bearing material and wherein said alumina is leached from said comminuted hardened bodies with a solution comprising sodium carbonate.
Claim 9
Dependent Claim
44 words
A process according to claim 1 wherein the amount of said lime is from 1 to 2 moles per mole of alumina in said alumina-bearing material and wherein said alumina is leached from said comminuted hardened bodies with a solution comprising a mineral acid.
Claim 10
Dependent Claim
12 words
A process according to claim 8 wherein said acid comprises nitric acid.
Claim 11
Dependent Claim
29 words
A process according to claim 9 wherein, after leaching with nitric acid, ammonia is added to the leaching solution to form an alumina precipitate and an ammonium nitrate solution.
Claim 12
Dependent Claim
27 words
A process according to claim 1 wherein said alumina-bearing material is selected from the group consisting of bauxite, clay, red mud, bentonite, volcanic tuff, and fly ash.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |