US3876749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the reduction treatment of red mud
Assignee: Magyar Aluminiumipari Troeszt
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Filing: 1972-04-10
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Granted: 1975-04-08
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Expires: 1992-04-10
Abstract
Abstract The red mud by-product of the Bayer aluminum manufacturing process is utilized by mixing the red mud with a reducing agent, reducing the red mud, separating it into molten steel and molten slag, reacting the slag with CaO, leaching out the useful aluminates for recirculation to the Bayer process, and utilizing the remaining calcium silicates in cement manufacture.
Inventors
- 👤 Gyula Horvath
- 👤 Zoltan Felfoldi
- 👤 Zoltan Oswald
- 👤 Karoly Solymar
- 👤 Adam Juhasz
- 👤 Gyorgy Dobos
- 👤 Gyorgy Kaptay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:52
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/04; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/06; C01F7/066; C21; C21B; C21B13/00; C21B13/08; C21B3/00; C21B3/04; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y02W; Y02W30/00; Y02W30/50; Y10; Y10S; Y10S75/00; Y10S75/958
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
190 words
IN A PROCESS FOR THE TREATMENT OF THE RED MUD BYPRODUCT OF THE BAYER ALUMINUM MANUFACTURING POCESS, WHEREIN A REDUCING AGENT IS ADDED TO THE RED MUD AND A CALCAREOUS MATERIAL IS EMPLOYED, AND THE MIXTURE IS MELTED UNDER REDUCING CONDITIONS AND THE MELT IS SEPARATED INTO A STEEL PHASE AND A SLAG PHASE, AND ALUMINUM VALUES ARE RECOVERED FROM THE SLAG PHASE, AND THE SLAG PHASE, AFTER PROCESSING IS COLLED, THE COOLED PRODUCT IS LEACHED, AND THE RESULTING LIQUID AND SOLID PHASE ARE SEPARATED, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT SAID MELTING WITHOUT THE PRIOR ADDITION OF A CALCAREOUS MATERIAL TO THE RED MUD, ADDING A CALCAREOUS MATERIAL TO THE SLAG PHASE MATERIAL IN A CONCENTRATION TO PROVIDE, TOGETHER WITH THE CAO CONTENT OF THE SLAG PHASE, THE FOLLOWING MOLAR RATIOS, WITHIN +- 10%, WITH THE SIO2, TIO2, FE2O3 AND AL2O3 CONTENT OF THE SLAG PHASE CAO;SIO2=2; CAO:TIO2=1; CAO: FE2O3=2; AND CAO:AL2O3=O.1 - 0.5 AND THEN HEATING THE RESULTING MIXTURE AT A TEMPERATURE FROM ABOUT 1,00*C TO ABOUT 1,600*C IN A SUBSTANTIALLY NEUTRAL OR OXIDIZING ATOMOSPHERE, WHEREBY THE SODIUM ALUMINATE FORMED DURING SAID HEATING BECOMES SOLUBLE FOR SUBSEQUENT RECOVERY.
Claim 2
Dependent Claim
190 words
IN A PROCESS FOR THE TREATMENT OF THE RED MUD BYPRODUCT OF THE BAYER ALUMINUM MANUFACTURING POCESS, WHEREIN A REDUCING AGENT IS ADDED TO THE RED MUD AND A CALCAREOUS MATERIAL IS EMPLOYED, AND THE MIXTURE IS MELTED UNDER REDUCING CONDITIONS AND THE MELT IS SEPARATED INTO A STEEL PHASE AND A SLAG PHASE, AND ALUMINUM VALUES ARE RECOVERED FROM THE SLAG PHASE, AND THE SLAG PHASE, AFTER PROCESSING IS COLLED, THE COOLED PRODUCT IS LEACHED, AND THE RESULTING LIQUID AND SOLID PHASE ARE SEPARATED, THE IMPROVEMENT WHICH COMPRISES CARRYING OUT SAID MELTING WITHOUT THE PRIOR ADDITION OF A CALCAREOUS MATERIAL TO THE RED MUD, ADDING A CALCAREOUS MATERIAL TO THE SLAG PHASE MATERIAL IN A CONCENTRATION TO PROVIDE, TOGETHER WITH THE CAO CONTENT OF THE SLAG PHASE, THE FOLLOWING MOLAR RATIOS, WITHIN +- 10%, WITH THE SIO2, TIO2, FE2O3 AND AL2O3 CONTENT OF THE SLAG PHASE CAO;SIO2=2; CAO:TIO2=1; CAO: FE2O3=2; AND CAO:AL2O3=O.1 - 0.5 AND THEN HEATING THE RESULTING MIXTURE AT A TEMPERATURE FROM ABOUT 1,00*C TO ABOUT 1,600*C IN A SUBSTANTIALLY NEUTRAL OR OXIDIZING ATOMOSPHERE, WHEREBY THE SODIUM ALUMINATE FORMED DURING SAID HEATING BECOMES SOLUBLE FOR SUBSEQUENT RECOVERY.
Claim 3
Dependent Claim
29 words
The improvement of the process of claim 1, further comprising the step of grinding the cooled product to a maximum particle size of 1 mm before the leaching thereof.
Claim 4
Dependent Claim
47 words
The improvement of the process of claim 2, further comprising the step of cooling the slag phase before contacting it with the calcareous material, then grinding the mixture and then sintering it at a temperature between 1,000.degree.C and 1,600.degree.C before said steps of cooling, grinding, and leaching.
Claim 5
Dependent Claim
24 words
The improvement of the process of claim 3, wherein the said step of sintering is carried out at a temperature between 1,100.degree.C and 1,400.degree.C.
Claim 6
Dependent Claim
27 words
The improvement of the process of claim 2, wherein said step of contacting with calcareous material is carried out while the slag phase is still substantially molten.
Claim 7
Dependent Claim
19 words
The improvement of the process of claim 5, wherein the substantially molten slag is contacted with preheated burnt lime.
Claim 8
Dependent Claim
53 words
The improvement of the process of claim 6, wherein the amount of burnt lime added to the slag is slightly in excess of the amount of CaO stoichiometrically required on the basis of the sodium content of the slag for decomposing the sodium silicate content of the slag thereby to form calcium silicate.
Claim 9
Dependent Claim
53 words
The improvement of the process of claim 2, wherein said step of leaching comprises a first leaching with a basic caustic solvent substantially to remove the sodium aluminate content of the slag phase, and a second leaching with a sodium carbonate solvent substantially to remove the calcium aluminate content of the slag phase.
Claim 10
Dependent Claim
21 words
The improvement of the process of claim 8, wherein the caustic solvent for said first leaching is a sodium aluminate solvent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |