Patent US4282190A successfully refreshed from Google Patents.
US4282190A
Expired / Lapsed
US
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Process for the manufacture of iron and aluminum-free zinc chloride solutions
Assignee: Evonik Operations GmbH
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Filing: 1979-11-08
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Granted: 1981-08-04
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Expires: 1999-11-08
Abstract
Abstract A process for the removal of iron and aluminum values from acidic solutions thereof with zinc chloride wherein the solution is subjected to pressure hydrolysis to precipitate the iron and aluminum as the hydroxides or oxide hydrates, and then the precipitate is removed and washed. Zinc chlorides which are particularly free from iron and aluminum can be rapidly and easily obtained with this process.
Inventors
- 👤 Wolfgang Muller
- 👤 Lothar Witzke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:31
CPC Classifications
C; C01; C01G; C01G9/00; C01G9/04; C01F; C01F7/00; C01F7/02; C01F7/34; C01G49/00; C01G49/02; C01G49/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
102 words
A process for the removal of iron and aluminum values from acidic solutions thereof with zinc chloride comprising: (a) treating the solution for a period of from about 0.1 to 3 hours at a pH of about 1.5 to 4 at a temperature from about 150° to 260° C. and a pressure of from 6 to 48 bar to convert the iron and aluminum values to the hydroxide or oxide hydrate, (b) rapidly cooling the reaction mixture to form a precipitate, and (c) separating the precipitate from the solution, and then subjecting the separated solution to steps (a), (b), and (c) again.
Claim 2
Dependent Claim
102 words
A process for the removal of iron and aluminum values from acidic solutions thereof with zinc chloride comprising: (a) treating the solution for a period of from about 0.1 to 3 hours at a pH of about 1.5 to 4 at a temperature from about 150° to 260° C. and a pressure of from 6 to 48 bar to convert the iron and aluminum values to the hydroxide or oxide hydrate, (b) rapidly cooling the reaction mixture to form a precipitate, and (c) separating the precipitate from the solution, and then subjecting the separated solution to steps (a), (b), and (c) again.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein an oxidizing agent is added to the reaction mixture before the treatment to convert or maintain the iron in the trivalent state.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein the oxygen partial pressure above the reaction mixture is increased to convert or maintain the iron in the trivalent state.
Claim 5
Dependent Claim
23 words
The process of claim 1, 2, or 3 wherein the rapid cooling is achieved by suddenly releasing the pressure over the reaction mixture.
Claim 6
Dependent Claim
20 words
The process of claim 1, 2, or 3 wherein the reaction mixture is cooled to about 100° to 120° C.
Claim 7
Dependent Claim
46 words
The process of claim 1, 2, or 3 wherein the pH of the solution is adjusted to the range from 1.5 to 3 by the addition of a neutralizing agent selected from the group consisting of alkali hydroxides, alkali carbonates, basic zinc salts and zinc oxide.
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) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |