Patent US4385903A successfully refreshed from Google Patents.
US4385903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Agent for promoting filtration dehydration of metal hydroxide slurry
Assignee: Kao Corp
•
Filing: 1981-10-29
•
Granted: 1983-05-31
•
Expires: 2001-10-29
Abstract
Abstract An aqueous slurry of a water-insoluble or slightly water-soluble metal hydroxide can be effectively filtrated and dehydrated by adding an anionic surfactant of the following formula (I): R--O--AO--.sub.n X (I) wherein R represents an alkyl or alkenyl group of 8-24 carbon atoms, A represents an alkyene group of 2-4 carbon atoms, X represents SO 3 M (M being H, K, Na or NH 4 ), PO 3 M (M being K or Na) or CH 2 COOM (M being K or Na), and n represents an interger of 1-100, to the aqueous slurry of the metal hydroxide or to the washing water.
Inventors
- 👤 Noboru Moriyama
- 👤 Takeshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:16
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/04; C01F7/14; C01F7/144; C01F7/148; B; B01; B01D; B01D37/00; B01D37/03
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
139 words
A process for dewatering an aqueous slurry of a water-insoluble metal hydroxide or a slightly water-soluble metal hydroxide, comprising: adding to the slurry, as a dewatering aid, an effective amount of an anionic surfactant having the formula R--O--AO--.sub.n X wherein n is an integer of from 1 to 100, R is alkyl or alkenyl having from 8 to 24 carbon atoms, A is alkylene having from 2 to 4 carbon atoms, and X is SO 3 M, PO 3 M 1 , or CH 2 COOM 1 , M is H, K, Na or NH 4 and M 1 is K or Na, so that said anionic surfactant is adsorbed on the surfaces of the metal hydroxide particles to render said surfaces hydrophobic, and then filtering said aqueous slurry to obtain a wet filter cake containing said metal hydroxide.
Claim 2
Dependent Claim
139 words
A process for dewatering an aqueous slurry of a water-insoluble metal hydroxide or a slightly water-soluble metal hydroxide, comprising: adding to the slurry, as a dewatering aid, an effective amount of an anionic surfactant having the formula R--O--AO--.sub.n X wherein n is an integer of from 1 to 100, R is alkyl or alkenyl having from 8 to 24 carbon atoms, A is alkylene having from 2 to 4 carbon atoms, and X is SO 3 M, PO 3 M 1 , or CH 2 COOM 1 , M is H, K, Na or NH 4 and M 1 is K or Na, so that said anionic surfactant is adsorbed on the surfaces of the metal hydroxide particles to render said surfaces hydrophobic, and then filtering said aqueous slurry to obtain a wet filter cake containing said metal hydroxide.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1, wherein said water-insoluble or water-slightly soluble metal hydroxide is aluminum hydroxide.
Claim 4
Dependent Claim
34 words
A process as claimed in claim 2, wherein said anionic surfactant is added in an amount of from 10 to 1000 ppm per unit weight of said metal hydroxide, calculated on a dry basis.
Claim 5
Dependent Claim
17 words
A process as claimed in claim 3, wherein A is alkylene having 3 or 4 carbon atoms.
Claim 6
Dependent Claim
34 words
A process as claimed in claim 1, wherein said anionic surfactant is added in an amount of from 100 to 500 ppm per unit weight of said metal hydroxide, calculated on a dry basis.
Claim 7
Dependent Claim
27 words
A process as claimed in claim 1, wherein R has from 12 to 20 carbon atoms, and n is in the range of from 3 to 15.
Claim 8
Dependent Claim
27 words
A process as claimed in claim 1, wherein R has from 14 to 18 carbon atoms, and n is in the range of from 3 to 10.
Claim 9
Dependent Claim
178 words
A process for dewatering an aqueous slurry of a water-insoluble metal hydroxide or a slightly water-soluble metal hydroxide, comprising: filtering said slurry to obtain a first wet filter cake containing said metal hydroxide; then washing said first wet filter cake with washing water containing, as a dewatering aid, an anionic surfactant having the formula R--O--AO--.sub.n X wherein n is an integer of from 1 to 100, R is alkyl or alkenyl having from 8 to 24 carbon atoms, A is alkylene having from 2 to 4 carbon atoms, and X is SO 3 M, PO 3 M 1 , or CH 2 COOM 1 wherein M is H, K, Na or NH 4 and M 1 is K or Na to incorporate in said first wet filter cake an effective amount of said anionic surfactant so that said anionic surfactant is adsorbed on the surfaces of the metal hydroxide particles to render said surfaces hydrophobic, and then again filtering said first wet filter cake containing said surfactant to obtain a second wet filter cake containing said metal hydroxide.
Claim 10
Dependent Claim
178 words
A process for dewatering an aqueous slurry of a water-insoluble metal hydroxide or a slightly water-soluble metal hydroxide, comprising: filtering said slurry to obtain a first wet filter cake containing said metal hydroxide; then washing said first wet filter cake with washing water containing, as a dewatering aid, an anionic surfactant having the formula R--O--AO--.sub.n X wherein n is an integer of from 1 to 100, R is alkyl or alkenyl having from 8 to 24 carbon atoms, A is alkylene having from 2 to 4 carbon atoms, and X is SO 3 M, PO 3 M 1 , or CH 2 COOM 1 wherein M is H, K, Na or NH 4 and M 1 is K or Na to incorporate in said first wet filter cake an effective amount of said anionic surfactant so that said anionic surfactant is adsorbed on the surfaces of the metal hydroxide particles to render said surfaces hydrophobic, and then again filtering said first wet filter cake containing said surfactant to obtain a second wet filter cake containing said metal hydroxide.
Claim 11
Dependent Claim
32 words
A process as claimed in claim 8, wherein the amount of said anionic surfactant is from 10 to 1000 ppm per unit weight of said metal hydroxide, calculated on a dry basis.
Claim 12
Dependent Claim
17 words
A process as claimed in claim 8, wherein A is alkylene having 3 or 4 carbon atoms.
Claim 13
Dependent Claim
31 words
A process as claimed in claim 8, wherein the amount of said surfactant is from 100 to 500 ppm per unit weight of said metal hydroxide, calculated on a dry basis.
Claim 14
Dependent Claim
27 words
A process as claimed in claim 8, wherein R has from 12 to 20 carbon atoms and n is in the range of from 3 to 15.
Claim 15
Dependent Claim
23 words
A process as claimed in claim 8, wherein R has from 14 to 18 carbon atoms and n is from 3 to 10.
Claim 16
Dependent Claim
15 words
A process as claimed in claim 8 in which said metal hydroxide is aluminum hydroxide.
References Cited (Backward Citations)
US2894898A
Cited
US3020230A
Cited
US3020229A
Cited
US3194758A
Cited
US3436199A
Cited
JPS472429U
Cited
US3798160A
Cited
SU443682A1
Cited
US4009103A
Cited
SU596545A1
Cited
US4291004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-30 | 1986-11-29 | 1987-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-30 | 1990-11-29 | 1991-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-30 | 1994-11-29 | 1995-05-31 | $7700.00 | Window Closed / Lapsed |