US4087276A
Expired / Lapsed
US
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Removal of mercury from sludge by heating and condensing
Assignee: Anic SpA
•
Filing: 1977-07-15
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Granted: 1978-05-02
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Expires: 1997-07-15
Abstract
Abstract A method is disclosed for stripping mercury from mercury-containing sludges, the improvement consisting in that the sludges are first dried and then roasted, all these operations being carried out under a subatmospherical pressure, a final condensation of the vapor phases takes place under superatmospherical pressure. A high efficiency of recovery is thus warranted.
Inventors
- 👤 Gianni Generini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:47
CPC Classifications
C; C02; C02F; C02F9/00; C01; C01G; C01G13/00; C02F1/00; C02F1/02; C02F1/04; C02F1/048; C02F1/58; C02F11/00; C02F11/12; C02F11/13; C22; C22B; C22B43/00; C02F2101/00; C02F2101/10; C02F2101/20; C02F2301/00; C02F2301/06; C02F2301/063
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
123 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) heating the sludge at a temperature of from 200° C to 340° C and at a pressure of from 0.06 to 0.1 atmospheres to vaporize the mercury, the sludge having a pH of from 8 to 9 and containing less than 45 to 50% water; (b) condensing mercury vapor from step (a) at a temperature of from 20° C to 50° C and at a pressure of from 0.06 to 0.1 atmospheres; and (c) then condensing at a temperature comprised between 5° C and 30° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (a) not condensed in step (b).
Claim 2
Independent Claim
123 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) heating the sludge at a temperature of from 200° C to 340° C and at a pressure of from 0.06 to 0.1 atmospheres to vaporize the mercury, the sludge having a pH of from 8 to 9 and containing less than 45 to 50% water; (b) condensing mercury vapor from step (a) at a temperature of from 20° C to 50° C and at a pressure of from 0.06 to 0.1 atmospheres; and (c) then condensing at a temperature comprised between 5° C and 30° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (a) not condensed in step (b).
Claim 3
Dependent Claim
22 words
The method of claim 1 which comprises an additional step of rendering the sludge alkaline prior to the heating of step (a).
Claim 4
Dependent Claim
10 words
The method of claim 1 wherein the method is continuous.
Claim 5
Independent Claim
129 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to vaporize the mercury; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50° C and at a pressure of from 0.06 to 0.1 atmospheres; and (d) then condensing at a temperature between 5° C and 30° C and at a pressure of between 2 and 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 6
Independent Claim
129 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to vaporize the mercury; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50° C and at a pressure of from 0.06 to 0.1 atmospheres; and (d) then condensing at a temperature between 5° C and 30° C and at a pressure of between 2 and 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 7
Independent Claim
153 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) heating the sludge at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to produce residual sludge in the form of ash and vapor containing mercury and water, the sludge heated having a pH of from 8 to 9 and containing less than 45 to 50% water; (b) condensing vapor from step (a) at a temperature of from 20° C to 50° C and at a pressure of 0.06 to 0.1 atmospheres to obtain a condensate comprised of water and mercury; (c) separating the condensate from step (b) into water and mercury; and (d) then condensing at a temperature comprised between 5° C and 30° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (a) not condensed in step (b).
Claim 8
Independent Claim
153 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) heating the sludge at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to produce residual sludge in the form of ash and vapor containing mercury and water, the sludge heated having a pH of from 8 to 9 and containing less than 45 to 50% water; (b) condensing vapor from step (a) at a temperature of from 20° C to 50° C and at a pressure of 0.06 to 0.1 atmospheres to obtain a condensate comprised of water and mercury; (c) separating the condensate from step (b) into water and mercury; and (d) then condensing at a temperature comprised between 5° C and 30° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (a) not condensed in step (b).
Claim 9
Dependent Claim
21 words
The method of claim 5 wherein step (d) is carried out at a temperature of from 4° C to 6° C.
Claim 10
Dependent Claim
16 words
The method of claim 5 wherein the residual sludge from step (a) is dissolved in water.
Claim 11
Independent Claim
160 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to produce residual sludge in the form of ash and vapor containing mercury and water; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50° C and at a pressure of 0.06 to 0.1 atmospheres to obtain a condensate comprised of water and mercury; (d) separating the condensate from step (c) into water and mercury; and (e) then condensing at a temperature comprised between 5° C and 35° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 12
Independent Claim
160 words
A method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to produce residual sludge in the form of ash and vapor containing mercury and water; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50° C and at a pressure of 0.06 to 0.1 atmospheres to obtain a condensate comprised of water and mercury; (d) separating the condensate from step (c) into water and mercury; and (e) then condensing at a temperature comprised between 5° C and 35° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 13
Dependent Claim
16 words
The method of claim 8 wherein the residual sludge from step (a) is dissolved in water.
Claim 14
Dependent Claim
130 words
A continuous method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to vaporize the mercury; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50° C and at a pressure of from 0.06 to 0.1 atmospheres; and (d) then condensing at a temperature between 5° C and 30° C and at a pressure of between 2 and 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 15
Dependent Claim
130 words
A continuous method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to vaporize the mercury; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50° C and at a pressure of from 0.06 to 0.1 atmospheres; and (d) then condensing at a temperature between 5° C and 30° C and at a pressure of between 2 and 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 16
Dependent Claim
161 words
A continuous method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to produce residual sludge in the form of ash and vapor containing mercury and water; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50 C and at a pressure of 0.06 to 0.1 atmospheres to obtain a condensate comprised of water and mercury; (d) separating the condensate from step (c) into water and mercury; and (e) then condensing at a temperature comprised between 5° C and 350° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (b) not condensed in step (c).
Claim 17
Dependent Claim
161 words
A continuous method for the removal of mercury from sludge containing mercury, comprising the steps of: (a) treating the sludge to have a pH of from 8 to 9 and to contain less than 45 to 50% water; (b) heating the sludge from step (a) at a temperature of from 200° C to 350° C and at a pressure of from 0.06 to 0.1 atmospheres to produce residual sludge in the form of ash and vapor containing mercury and water; (c) condensing mercury vapor from step (b) at a temperature of from 20° C to 50 C and at a pressure of 0.06 to 0.1 atmospheres to obtain a condensate comprised of water and mercury; (d) separating the condensate from step (c) into water and mercury; and (e) then condensing at a temperature comprised between 5° C and 350° C and at a pressure of from 2 to 3 atmospheres the mercury vapor from step (b) not condensed in 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) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |