US4336142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of heavy metals with gamma dicalcium silicate
Assignee: Blue Circle Industries PLC
•
Filing: 1981-03-04
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Granted: 1982-06-22
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Expires: 2001-03-04
Abstract
Abstract According to the present invention we provide a method of controlling the heavy metal content of the water in an aqueous system which comprises incorporating in the system an amount of gamma dicalcium silicate to insolubilize heavy metals present.
Inventors
- 👤 Gerald C. Bye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:43
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912; Y10S210/913
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A method of removing a heavy metal, whose ions are insoluble in an aqueous medium having a pH in the range of 7-11, from an aqueous system contaminated with ions of said heavy metal, which comprises the steps of (1) contacting the heavy metal ions in the aqueous system with an amount of gamma dicalcium silicate effective to establish a final pH in the aqueous system in the range of 7-11 and to insolubilize said heavy metal present, and (2) separating the insolubilized heavy metal from the aqueous system.
Claim 2
Independent Claim
89 words
A method of removing a heavy metal, whose ions are insoluble in an aqueous medium having a pH in the range of 7-11, from an aqueous system contaminated with ions of said heavy metal, which comprises the steps of (1) contacting the heavy metal ions in the aqueous system with an amount of gamma dicalcium silicate effective to establish a final pH in the aqueous system in the range of 7-11 and to insolubilize said heavy metal present, and (2) separating the insolubilized heavy metal from the aqueous system.
Claim 3
Dependent Claim
32 words
A method according to claim 1, wherein the heavy metal includes trivalent metal and the pH value of the aqueous system after insolubilisation of the heavy metal is from 7 to 9.
Claim 4
Dependent Claim
15 words
A method according to claim 2, wherein the heavy metal comprises aluminium, chromium or iron.
Claim 5
Dependent Claim
31 words
A method according to claim 1, wherein the heavy metal is divalent and the pH value of the aqueous system after insolubilization of the heavy metal is from 9 to 11.
Claim 6
Dependent Claim
16 words
A method according to claim 4, wherein the heavy metal comprises cadmium, copper, nickel or zinc.
Claim 7
Dependent Claim
18 words
A method according to claim 1, wherein the gamma dicalcium silicate is in the form of a powder.
Claim 8
Dependent Claim
17 words
A method according to claim 1, wherein the gamma dicalcium silicate is in the form of pellets.
Claim 9
Dependent Claim
38 words
A method according to claim 7, wherein the pellets are arranged in the form of a bed of pellets, and the aqueous system is contacted with said gamma dicalcium silicate by passing said aqueous system through said bed.
Claim 10
Dependent Claim
18 words
A method according to claim 1, wherein the gamma dicalcium silicate is in the form of a slurry.
Claim 11
Dependent Claim
26 words
A method according to claim 1, wherein a salt of iron or aluminium is added to the system before said contacting with the gamma dicalcium silicate.
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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) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |