Patent US4711727A successfully refreshed from Google Patents.
US4711727A
Expired / Lapsed
US
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Compositions comprising mineral particles in suspension and method of treating aqueous systems therewith
Assignee: Blue Circle Industries PLC
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Filing: 1986-07-29
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Granted: 1987-12-08
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Expires: 2006-07-29
Abstract
Abstract An aqueous slurry of mineral particles, for example calcium carbonate and/or calcium hydroxide, has a mineral solids concentration of at least 40% m/m and contains an agent that maintains the slurry at a pumpable viscosity but that acts as a flocculant upon dilution of the slurry. Suitable agents include cationic and amphoteric polyelectrolytes having nitrogen-containing groups, for example polyamines and dimethyl diallyl ammonium chloride polymers. The slurries may contain other components, for example a synthetic hectorite or a dispersing agent such as a polyacrylate, polymethacrylate or polyphosphate. The slurries are useful in papermaking and in the treatment of sewage.
Inventors
- 👤 Kenneth B. Matthews
- 👤 Christine A. Beckett
- 👤 David E. Smith
- 👤 Richard R. Davidson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:49
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/5227; C02F1/54; D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/69
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
179 words
A method of treating an aqueous system in order to effect flocculation of particulate matter within the treated system, which method comprises the steps of (1) taking a composition comprising (a) an aqueous slurry of mineral particles of at least 40% m/m mineral solids concentration and (b) an agent or mixture of agents that at least substantially maintains the mobility of the slurry, such that the apparent viscosity of the slurry does not exceed 500 cP (as measured at a shear rate of 600 s -1 ), and that exerts a flocculating action upon dilution of the composition with or into water at a dilution ratio of at least 20:1 (m/m), said agent(s) being selected from cationic polyelectrolytes that have nitrogen-containing groups, amphoteric polyelectrolytes that have nitrogen-containing groups and, provided that the said mineral particles include calcium hydroxide particles, anionic polyacrylamides, (2) adding to the aqueous system an amount of the said composition effective to cause flocculation of particulate matter in the resultant mixture and (3) separating the resultant flocculated particulate matter from the water of the aqueous system.
Claim 2
Independent Claim
179 words
A method of treating an aqueous system in order to effect flocculation of particulate matter within the treated system, which method comprises the steps of (1) taking a composition comprising (a) an aqueous slurry of mineral particles of at least 40% m/m mineral solids concentration and (b) an agent or mixture of agents that at least substantially maintains the mobility of the slurry, such that the apparent viscosity of the slurry does not exceed 500 cP (as measured at a shear rate of 600 s -1 ), and that exerts a flocculating action upon dilution of the composition with or into water at a dilution ratio of at least 20:1 (m/m), said agent(s) being selected from cationic polyelectrolytes that have nitrogen-containing groups, amphoteric polyelectrolytes that have nitrogen-containing groups and, provided that the said mineral particles include calcium hydroxide particles, anionic polyacrylamides, (2) adding to the aqueous system an amount of the said composition effective to cause flocculation of particulate matter in the resultant mixture and (3) separating the resultant flocculated particulate matter from the water of the aqueous system.
Claim 3
Dependent Claim
48 words
A method according to claim 1 in which the said mineral particles are selected from alkaline earth metal oxides, alkaline earth metal hydroxides, alkaline earth metal carbonates, alkaline earth metal bicarbonates, alkaline earth metal sulfates, clay, talc, titanium dioxide, zinc oxide, lithopone and mixtures of any of these.
Claim 4
Dependent Claim
22 words
A method according to claim 1, in which the said mineral particles are selected from calcium carbonate, calcium hydroxide and mixtures thereof.
Claim 5
Dependent Claim
29 words
A method according to claim 3, in which the said mineral particles comprise a mixture of calcium carbonate and calcium hydroxide at a weight ratio of 19:1 to 1:19.
Claim 6
Dependent Claim
31 words
A method according to claim 1, 2 or 3 in which component (b) of the composition defined in step (1) is selected from polyamines, polyimines and dimethyl diallyl ammonium chloride polymers.
Claim 7
Dependent Claim
33 words
A method according to claim 5 in which the said component (b) is selected from quaternary polyamines, dimethyl diallyl ammonium chloride homopolymers, dimethyl diallyl ammonium chloride/acrylamide copolymers and mixtures of any of these.
Claim 8
Dependent Claim
34 words
A method according to claim 1 in which the said component (b) is present in the composition defined in step (1) in an amount of from 0.0075% to 2% on a dry weight basis.
Claim 9
Dependent Claim
45 words
A method according to claim 1 in which the composition defined in step (1) also comprises one or more components selected from the group consisting of synthetic hectorite, polyphosphoric acids and their salts, polyacrylic acids and their salts, polymethacrylic acids and their salts, and lignosulfonates.
Claim 10
Dependent Claim
22 words
A method according to claim 1 in which the composition defined in step (1) is diluted prior to the adding step (2).
Claim 11
Dependent Claim
42 words
A method according to claim 1 in which the composition defined in step (1) is added in step (2) at a rate of from 100 to 1000 ppm on a dry mineral basis relative to the total aqueous system to be treated.
Claim 12
Dependent Claim
24 words
A method according to claim 1 in which the aqueous system to be treated is selected from sewage and other waste waters requiring clarification.
Claim 13
Dependent Claim
24 words
A method according to claim 11, in which alum is added to the system after the addition of the said composition in step (2).
Claim 14
Dependent Claim
46 words
A method according to claim 1 in which the aqueous system to be treated is papermaking stock, the said mineral particles are suitable for use as a papermaking filler and step (3) is effected during the formation of a paper sheet from the said papermaking stock.
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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) | 1990-12-07 | 1991-06-08 | 1991-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-07 | 1995-06-08 | 1995-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-07 | 1999-06-08 | 1999-12-08 | $7700.00 | Window Closed / Lapsed |