Patent US4379837A successfully refreshed from Google Patents.
US4159310A
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Process for recovering aluminum and other metal values from fly ash
Assignee: Public Service Company of New Mexico
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Filing: 1978-01-30
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Granted: 1979-06-26
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Expires: 1998-01-30
Abstract
Abstract A process for recovering aluminum from fly ash containing iron, silicon and titanium which comprises: (a) chlorinating the fly ash in an oxidizing atmosphere to selectively chlorinate and vaporize iron chloride from the remaining chlorides, (b) chlorinating the residue from step (a) in a reducing atmosphere of carbon monoxide, in the presence of added silicon chloride to suppress the chlorination of silicon, and vaporizing the chlorides of aluminum, silicon, titanium, and the residual iron, (c) separating and recovering the vaporized chlorides by selective condensation, and treating the residue of step (b) with sulfuric acid to convert calcium chloride to gypsum, and to regenerate a chloridizing and binder solution for pelletizing fly ash feed.
Inventors
- 👤 James E. Reynolds
- 👤 Alan R. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:05
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/08; C01B33/107; C01B33/1071; C01B33/10715; C01B33/10721; B; B01; B01D; B01D49/00; B01D53/00; B01D53/34; B01D53/46; B01D53/68; C01F; C01F7/00; C01F7/48; C01F7/56; C01F7/58; C01F7/60; C01G; C01G23/00; C01G23/02; C01G23/022; C01G49/00; C01G49/10; C22; C22B; C22B21/00; C22B21/0038; C22B21/0046; C22B7/00; C22B7/02; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
A process for recovering aluminum from fly ash containing aluminum, iron and (silica) silicon which comprises: (a) chlorinating the material by subjecting it to the action of chlorine at a temperature of about 500° C.-1200° C. in an oxidizing atmosphere in the presence of added oxygen in an amount equal to about 5-100 volume percent of the chlorine to selectively vaporize iron as iron chloride; (b) chlorinating the residue from step (a) by subjecting it to the action of chlorine at a temperature of about 500° C.-1200° C. in a reducing atmosphere in the absence of solid carbon to vaporize the chlorides of aluminum (tatanium) and silicon; and (c) separating and recovering the formed (reacted) chlorides from the vapors by selective condensing.
Claim 2
Dependent Claim
122 words
A process for recovering aluminum from fly ash containing aluminum, iron and (silica) silicon which comprises: (a) chlorinating the material by subjecting it to the action of chlorine at a temperature of about 500° C.-1200° C. in an oxidizing atmosphere in the presence of added oxygen in an amount equal to about 5-100 volume percent of the chlorine to selectively vaporize iron as iron chloride; (b) chlorinating the residue from step (a) by subjecting it to the action of chlorine at a temperature of about 500° C.-1200° C. in a reducing atmosphere in the absence of solid carbon to vaporize the chlorides of aluminum (tatanium) and silicon; and (c) separating and recovering the formed (reacted) chlorides from the vapors by selective condensing.
Claim 3
Dependent Claim
25 words
The process of claim 1 in which the reductive chlorination of step (b) is performed in the presence of carbon monoxide as a reducing agent.
Claim 4
Dependent Claim
32 words
The process of claim 2 in which silicon tetrachloride is added to the residue from step (a) in an amount up to about 19.5 volume percent to suppress the chlorination of silicon.
Claim 5
Dependent Claim
19 words
The process of claim 3 in which the silicon tetrachloride is mixed with chlorine used as the chlorinating agent.
Claim 6
Dependent Claim
33 words
The process of claim 3 in which the reductive chlorination of step (b) is performed at about 1050° C. in the presence of silicon tetrachloride at a concentration of about 3 volume percent.
Claim 7
Dependent Claim
35 words
The process of claim 1 wherein the fly ash contains calcium and in which the material (residue of solid chlorides) from step (b) remaining after vaporization is reacted with sulfuric acid to produce disposable gypsum.
Claim 8
Dependent Claim
18 words
The process of claim 1 in which chlorine and oxygen are mixed for the chlorination of step (a).
Claim 9
Dependent Claim
25 words
The process of claim 1 in which the reductive chlorination of step (b) is performed in the presence of carbon monoxide as a reducing agent.
Claim 10
Dependent Claim
24 words
The process of claim 8 in which the carbon monoxide is introduced at a volume percent of about 20 percent to about 80 percent.
Claim 11
Dependent Claim
32 words
The process of claim 8 in which silicon tetrachloride is added to the residue from step (a) in an amount up to about 19.5 volume percent to suppress the chlorination of silicon.
Claim 12
Dependent Claim
18 words
The process of 10 in which the silicon tetrachloride is mixed with chlorine used as the chlorinating agent.
Claim 13
Dependent Claim
18 words
The process of 10 in which the silicon tetrachloride is mixed with chlorine used as the chlorinating agent.
Claim 14
Dependent Claim
23 words
The process of claim 11 in which the silicon tetrachloride is introduced in an amount of about 2.5 to about 19.5 volume percent.
Claim 15
Dependent Claim
40 words
The process of claim 1 wherein the fly ash contains calcium and in which the material (residue of solid chlorides) from step (b) remaining after vaporization is reacted with sulfuric acid to produce disposable gypsum and to form hydrochloric acid.
Claim 16
Dependent Claim
13 words
The process of claim 13 in which the fly ash feed is pelletized.
Claim 17
Dependent Claim
23 words
The process of claim 14 in which the fly ash feed is pelletized and bentonite is used as a binder for the pellets.
Claim 18
Dependent Claim
32 words
The process of claim 1 in which titanium is present in said fly ash and it is chlorinated in accordance with step (b) and separated and recovered in accordance with step (c).
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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) | 1982-06-25 | 1982-12-25 | 1983-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-25 | 1986-12-25 | 1987-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-25 | 1990-12-25 | 1991-06-26 | $7700.00 | Window Closed / Lapsed |