US4010186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of lead from aqueous solution using metallic magnesium
Assignee: PPG Industries Inc
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Filing: 1971-04-05
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Granted: 1977-03-01
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Expires: 1991-04-05
Abstract
Abstract A process is described for reducing the lead content of aqueous solution containing lead impurities in which the solution is contacted with metallic magnesium. Lead compounds are converted to water insoluble forms which are separated by recourse to physical processing such as steam distillation, filtration, settling, centrifugation, decantation and the like. In general, the process is conducted at pH of 7 to 11, preferably 8 to 9.5. Reaction temperature can be ambient temperature (25° C.) or higher. In one embodiment the reaction is conducted in a steam distillation zone. The magnesium is added at a rate to provide at least 0.5 mole of magnesium per mole of lead, preferably 0.75 mole to 1.5 moles or more of magnesium per mole of lead.
Inventors
- 👤 Thorowgood T. Broun, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:05
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/24; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
104 words
A method of reducing the dissolved organic lead content of aqueous solution resulting from manufacture of alkyllead compound, said aqueous solution containing contaminating quantities of dissolved organic lead and having a pH of from 7 to 11, comprising contacting said solution with at least 0.50 moles of metallic magnesium per mole of dissolved organic lead, said solution containing at least 0.1 weight percent added chloride ions, for a period of time sufficient to produce lead compounds that are insoluble in said solution, and separating insoluble lead compounds from the aqueous solution, thereby providing an aqueous solution containing substantially reduced levels of dissolved organic lead.
Claim 2
Independent Claim
104 words
A method of reducing the dissolved organic lead content of aqueous solution resulting from manufacture of alkyllead compound, said aqueous solution containing contaminating quantities of dissolved organic lead and having a pH of from 7 to 11, comprising contacting said solution with at least 0.50 moles of metallic magnesium per mole of dissolved organic lead, said solution containing at least 0.1 weight percent added chloride ions, for a period of time sufficient to produce lead compounds that are insoluble in said solution, and separating insoluble lead compounds from the aqueous solution, thereby providing an aqueous solution containing substantially reduced levels of dissolved organic lead.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein from 0.50 to 1.5 moles of metallic magnesium per mole of dissolved organic lead is used.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the temperature of the aqueous solution is from 10° C. to 110° C.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein the time period is from 1 to 48 hours.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein the chloride ion is provided by hydrochloric acid or sodium chloride.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein the pH of the aqueous solution contacted with metallic magnesium is between 8 and 9.5.
Claim 8
Dependent Claim
19 words
The method of claim 1 wherein from 0.1 to 3 weight percent chloride ions are present in the solution.
Claim 9
Independent Claim
130 words
A method of reducing the dissolved organic lead content of aqueous solution produced from washing the product of a redistribution reaction during manufacture of alkyllead compound with aqueous alkali metal hydroxide, said aqueous solution containing contaminting quantities of dissolved organic lead and having a pH of from 7 to 11, comprising contacting said solution with at least 0.50 moles of metallic magnesium per mole of dissolved organic lead, said solution containing from 0.1 to 3 weight percent added chloride ions, at from 80° C. to the boling point of the solution and for from 1 to 48 hours, to produce lead compounds that are insoluble in said solution and separating insoluble lead compounds from the aqueous solution, thereby providing an aqueous solution containing substantially reduced levels of dissolved organic lead.
Claim 10
Independent Claim
130 words
A method of reducing the dissolved organic lead content of aqueous solution produced from washing the product of a redistribution reaction during manufacture of alkyllead compound with aqueous alkali metal hydroxide, said aqueous solution containing contaminting quantities of dissolved organic lead and having a pH of from 7 to 11, comprising contacting said solution with at least 0.50 moles of metallic magnesium per mole of dissolved organic lead, said solution containing from 0.1 to 3 weight percent added chloride ions, at from 80° C. to the boling point of the solution and for from 1 to 48 hours, to produce lead compounds that are insoluble in said solution and separating insoluble lead compounds from the aqueous solution, thereby providing an aqueous solution containing substantially reduced levels of dissolved organic lead.
Claim 11
Dependent Claim
19 words
The method of claim 8 wherein the metallic magnesium and aqueous solution are contacted in a steam distillation zone.
Claim 12
Dependent Claim
38 words
The method of claim 8 wherein from 0.50 to 1.5 moles of metallic magnesium per mole of dissolved organic lead is used and the pH of the aqueous solution contacted with metallic magnesium is between 8 and 9.5.
Claim 13
Dependent Claim
17 words
The method of claim 10 wherein the chloride ion is provided by hydrochloric acid or sodium chloride.
Claim 14
Dependent Claim
17 words
The method of claim 8 wherein the solution contains from 0.2 to 1 weight percent chloride ions.
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) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |