Patent US3847598A successfully refreshed from Google Patents.
US3847598A
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Mercury recovery process
Assignee: BP Chemicals Ltd
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Filing: 1973-09-20
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Granted: 1974-11-12
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Expires: 1993-09-20
Abstract
Abstract Mercury is recovered from aqueous solutions containing elemental mercury in finely divided or colloidal form or in the form of a soluble inorganic compound by passing a stream of inert gas eg., air or nitrogen through the aqueous solution in the presence of a reducing agent, preferred reducing agents being ferrous sulphate at a pH greater than 5, hydrazine, hydroxylamine, D-glucose and sodium borohydride in alkaline solution. It is advantageous to operate at temperatures in the range 35*C to 95*C.
Inventors
- 👤 M Coulter
- 👤 D Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:06
CPC Classifications
C; C02; C02F; C02F9/00; C02F1/00; C02F1/58; C02F1/70; C22; C22B; C22B43/00; C02F2101/00; C02F2101/10; C02F2101/20; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912; Y10S210/914
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
A PROCESS FOR RECOVERING MERCURY FROM AQUEOUS ALKALINE SOLUTIONS CONTAINING MERCURY IN THE FORM OF SOLUBLE INORGANIC COMPOUND WHICH PROCESS COMPRISES PASSING A STREAM OF INERT GAS THROUGH SAID AQUEOUS ALKALINE SOLUTION AT A TEMPERATURE IN THE RANGE OF 5* TO 100*C IN THE PRESENCE OF A REDUCING AGENT ACTIVE FOR THE CHEMICAL REDUCTION OF SAID INORGANIC MERCURY COMPOUNDS TO ELEMENTAL MERCURY SELECTED FROM THE GROUP CONSISTING OF FERROUS SULPHATE, HYDRAZINE, HYDROXYLAMINE, D-GLUCOSE, AND SODIUM BOROHYDRIDE, AND SUBESQUENTLY RECOVERING THE MERCURY VAPOR FROM THE INERT GAS.
Claim 2
Dependent Claim
86 words
A PROCESS FOR RECOVERING MERCURY FROM AQUEOUS ALKALINE SOLUTIONS CONTAINING MERCURY IN THE FORM OF SOLUBLE INORGANIC COMPOUND WHICH PROCESS COMPRISES PASSING A STREAM OF INERT GAS THROUGH SAID AQUEOUS ALKALINE SOLUTION AT A TEMPERATURE IN THE RANGE OF 5* TO 100*C IN THE PRESENCE OF A REDUCING AGENT ACTIVE FOR THE CHEMICAL REDUCTION OF SAID INORGANIC MERCURY COMPOUNDS TO ELEMENTAL MERCURY SELECTED FROM THE GROUP CONSISTING OF FERROUS SULPHATE, HYDRAZINE, HYDROXYLAMINE, D-GLUCOSE, AND SODIUM BOROHYDRIDE, AND SUBESQUENTLY RECOVERING THE MERCURY VAPOR FROM THE INERT GAS.
Claim 3
Dependent Claim
17 words
A process according to claim 1 wherein the temperature is in the range of 35* to 95*C.
Claim 4
Dependent Claim
14 words
A process according to claim 1 wherein the inert gas is air or nitrogen.
Claim 5
Dependent Claim
26 words
A process according to claim 1, wherein the pH of the aqueous solution containing the inorganic mercury compound is adjusted to a value of about 11.
Claim 6
Dependent Claim
13 words
A process according to claim 1, wherein the reducing agent is sodium borohydride.
Claim 7
Dependent Claim
67 words
A process according to claim 1, wherein an initial reducing agent selected from the group consisting of sodium sulphite and sulphur dioxide is used to reduce oxidizing agents other than mercury compounds which are present in the aqueous alkaline solution, and a final reducing agent selected from the group consisting of hydrazine, hydroxylamine, D-glucose, and sodium borohydride is used for the final reduction of the mercury salts.
Claim 8
Dependent Claim
43 words
A process according to claim 1, wherein the mercury vapor is recovered from the inert gas stream by washing the stream with a solution of brine containing dissolved chlorine and cycling the brine solution containing the mercury to a mercury cathode electrolytic cell.
Claim 9
Dependent Claim
50 words
A process according to claim 1, wherein the mercury vapor is recovered from the inert gas stream by scrubbing the stream with an alkaline solution of an alkali metal hypochlorite containing an alkali metal chloride or calcium chloride substantially in excess of the chemical equivalent of the alkali metal hypochlorite.
Claim 10
Dependent Claim
22 words
A process according to claim 1, wherein the alkaline aqueous solution is a caustic soda solution manufactured by the mercury cathode process.
References Cited (Backward Citations)
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US3437476A
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US3537843A
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US3647359A
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US3785942A
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US3695838A
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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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |