US4049546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decolorization of effluents from pulp mills
Assignee: Rohm and Haas Co
•
Filing: 1976-03-23
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Granted: 1977-09-20
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Expires: 1996-03-23
Abstract
Abstract Pulp mill effluents particularly unbleached streams are decolorized by passing those streams through a mass or bed of macroreticular aliphatic weak anion exchange resin at a pH of 6 - 8.5. Preferred resins are further characterized as possessing a high pK a .
Inventors
- 👤 Steven L. Rock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:09
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/28; C02F1/285; B; B01; B01J; B01J41/00; B01J41/04; B01J41/07; Y; Y02; Y02W; Y02W10/00; Y02W10/30; Y02W10/37; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/917
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
68 words
Process for removing lignin and lignin by-product color bodies from an unbleached kraft pulp mill stream which comprises passing said stream at a pH of 6-8.5 through a mass or bed of macroreticular aliphatic weak anion exchange resin possessing high pk a value of between about 5.0 and about 10.0 in the free base form, thereby removing the lignin and lignin by-product color bodies on to the resin.
Claim 2
Dependent Claim
68 words
Process for removing lignin and lignin by-product color bodies from an unbleached kraft pulp mill stream which comprises passing said stream at a pH of 6-8.5 through a mass or bed of macroreticular aliphatic weak anion exchange resin possessing high pk a value of between about 5.0 and about 10.0 in the free base form, thereby removing the lignin and lignin by-product color bodies on to the resin.
Claim 3
Dependent Claim
16 words
A process as claimed in claim 1 wherein the resin comprises a functionalized methyl acrylate/divinyl-benzene copolymer.
Claim 4
Dependent Claim
15 words
A process as claimed in claim 1 wherein the resin comprises a functionalized methylacrylate/acrylonitrile copolymer.
Claim 5
Dependent Claim
24 words
A process as claimed in claim 1 wherein the resin is characterized as having a pK a value in the range of from 6-9.5.
Claim 6
Dependent Claim
18 words
A process as claimed in claim 1 wherein the resin when exhausted is regenerated by a caustic solution.
Claim 7
Dependent Claim
14 words
A process according to claim 1 wherein the aliphatic resin has an acrylic backbone.
Claim 8
Dependent Claim
25 words
The process as claimed in claim 1 wherein the weak anion exchange resin is regenerated by contact with a pulp mill process stream containing NaOH.
Claim 9
Dependent Claim
24 words
The process as claimed in claim 7 wherein the pulp mill process stream is a caustic process stream containing NaOH and Na 2 S.
Claim 10
Dependent Claim
29 words
The process of claim 7 wherein the pulp mill process stream containing NaOH is further used in paper pulping after being used to regenerate the weak anion exchange resin.
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) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |