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Patent US4305827A successfully refreshed from Google Patents.
US4305827A
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Heavy metal adsorbents of high selectivity, process for production of same, and adsorption process
Assignee: Unitika Ltd
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Filing: 1980-05-30
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Granted: 1981-12-15
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Expires: 2000-05-30
Abstract
Abstract A heavy metal adsorbent of high selectivity, a process for the production thereof, and an adsorption process using the heavy metal adsorbent are described; the adsorbent exhibits high adsorptivity particularly for mercury, and has excellent chemical stability, e.g., heat resistance and alkali resistance, and dimensional stability. This adsorbent is applicable, e.g., to the removal of mercury from waste water resulting from the washing of smoke in huge incineration stations, from saturated brine used in the sodium industry in an ion exchange membrane method, and so forth.
Inventors
- 👤 Akio Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:48
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/28; C02F1/283; B; B01; B01J; B01J20/00; B01J20/02; B01J20/20; C01; C01B; C01B17/00; C01B17/69; C01B17/90; C01B17/906; C01D; C01D3/00; C01D3/14; C01D3/16
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
31 words
A heavy metal adsorbent of high selectivity which is prepared by treating active carbon with at least one water-soluble primary or secondary amine and carbon disulfide in the presence of water.
Claim 2
Dependent Claim
31 words
A heavy metal adsorbent of high selectivity which is prepared by treating active carbon with at least one water-soluble primary or secondary amine and carbon disulfide in the presence of water.
Claim 3
Dependent Claim
28 words
An adsorbent as in claim 1, wherein 0.2 to 0.5 equivalent of carbon disulfide is used per equivalent of primary or secondary amino group of the water-soluble amine.
Claim 4
Dependent Claim
23 words
A heavy metal adsorbent as in claim 1, wherein the grain size of the active carbon is from about 10 to 100 mesh.
Claim 5
Dependent Claim
22 words
A heavy metal absorbent as in claim 1, wherein the grain size of the active carbon is from 20 to 60 mesh.
Claim 6
Dependent Claim
21 words
A heavy adsorbent as in claim 1, wherein the active carbon is derived from coconut shell carbon activated at low temperature.
Claim 7
Dependent Claim
33 words
A process for producing a heavy metal adsorbent of high selectivity which comprises treating active carbon with at least one water-soluble primary or secondary amine and carbon disulfide in the presence of water.
Claim 8
Dependent Claim
33 words
A process for producing a heavy metal adsorbent of high selectivity which comprises treating active carbon with at least one water-soluble primary or secondary amine and carbon disulfide in the presence of water.
Claim 9
Dependent Claim
28 words
A process as in claim 6, wherein 0.2 to 0.5 equivalent of carbon disulfide is used per equivalent of primary or secondary amino group of the water-soluble amine.
Claim 10
Dependent Claim
43 words
A process as in claim 6, wherein the water-soluble amine and disulfide are initially allowed to permeate the active carbon in the presence of water at a temperature of 40° C. or less for a period of from 10 minutes to 5 hours.
Claim 11
Dependent Claim
20 words
A process as in claim 8, wherein the temperature during the permeation period is from 10° C. to 40° C.
Claim 12
Dependent Claim
18 words
A process as in claim 8, wherein the period for permeation is from 30 minutes to 2 hours.
Claim 13
Dependent Claim
37 words
A process as in claim 6, 7, 8, 9, or 10, wherein the amine is first adsorbed on the active carbon, and after removing unadsorbed amine, the active carbon containing adsorbed amine is reacted with carbon disulfide.
Claim 14
Dependent Claim
28 words
A process as in claim 6, 7, 8, 9, or 10, wherein the treatment of the active carbon is conducted at from about 40° C. to 100° C.
Claim 15
Dependent Claim
16 words
A process as in claim 12, wherein the temperature is from 40° C. to 95° C.
Claim 16
Dependent Claim
16 words
A process as in claim 13, wherein the temperature is from 65° C. to 90° C.
Claim 17
Dependent Claim
21 words
A process as in claim 6, wherein the grain size of the active carbon is from about 10 to 100 mesh.
Claim 18
Dependent Claim
20 words
A process as in claim 6, wherein the grain size of the active carbon is from 20 to 60 mesh.
Claim 19
Dependent Claim
47 words
An adsorption process of a heavy metal-containing solution which comprises bringing a heavy metal adsorbent of high selectivity prepared by treating active carbon with at least one water-soluble primary or secondary amine and carbon disulfide in the presence of water into contact with a heavy metal-containing solution.
Claim 20
Dependent Claim
47 words
An adsorption process of a heavy metal-containing solution which comprises bringing a heavy metal adsorbent of high selectivity prepared by treating active carbon with at least one water-soluble primary or secondary amine and carbon disulfide in the presence of water into contact with a heavy metal-containing solution.
Claim 21
Dependent Claim
13 words
An adsorption process as in claim 17, wherein the heavy metal is mercury.
Claim 22
Dependent Claim
13 words
An adsorption process as in claim 17, wherein the heavy metal is silver.
Claim 23
Dependent Claim
16 words
An adsorption process as in claim 18, wherein the mercury is contained in concentrated sulfuric acid.
Claim 24
Dependent Claim
19 words
An adsorption process as in claim 18, wherein the mercury is in the form of an organic mercury compound.
Claim 25
Dependent Claim
24 words
An adsorbent process as in claim 17, 18, 19, 20, or 21, wherein the contact time is from about 4 hours to 8 hours.
Claim 26
Dependent Claim
22 words
An adsorbent process as in claim 22, wherein the temperature during contact is maintained at from about 45° C. to 100° C.
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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |