Patent US4226672A successfully refreshed from Google Patents.
US4226672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of separating asbestos fibers and product thereof
Assignee: CLIFF RESOURCES Corp
•
Filing: 1978-06-27
•
Granted: 1980-10-07
•
Expires: 1998-06-27
Abstract
Abstract A process of separating fibres from asbestos-bearing material which process comprises the steps by treating said asbestos-bearing material with a chemical agent capable of reacting with, or adsorbing on, asbestos fibres to form a dispersion, and agglomerating said dispersion. The process gives high yields of novel fibres characterized in that the said fibres provide reinforcement in cementitious compositions.
Inventors
- 👤 Victor J. Absolon
- 👤 George T. Hurst
- 👤 John C. Worboys
- 👤 George H. Barnett
- 👤 Ross P. Dickson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:36
CPC Classifications
C; C04; C04B; C04B20/00; C04B20/02; C04B20/08
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
110 words
A process for separating asbestos fibres from asbestos-bearing material selected from the group consisting of crude ore, fibre concentrates, mine wastes and tailings, which process includes the following steps: (1) a contacting step where the asbestos-bearing material is treated with a solution containing a surfactant adsorbable on or reactable with asbestos to form a viscous slurry dispersion, (2) a mechanical fiberising step, (3) a dilution step to reduce slurry viscosity without inducing coagulation of the fibres, (4) a classification step to remove unwanted grit, (5) a slurry dilution step sufficient to induce coagulation of fibres and form stringy fibre agglomerates, and (6) a dewatering step to recover the asbestos fibres.
Claim 2
Dependent Claim
110 words
A process for separating asbestos fibres from asbestos-bearing material selected from the group consisting of crude ore, fibre concentrates, mine wastes and tailings, which process includes the following steps: (1) a contacting step where the asbestos-bearing material is treated with a solution containing a surfactant adsorbable on or reactable with asbestos to form a viscous slurry dispersion, (2) a mechanical fiberising step, (3) a dilution step to reduce slurry viscosity without inducing coagulation of the fibres, (4) a classification step to remove unwanted grit, (5) a slurry dilution step sufficient to induce coagulation of fibres and form stringy fibre agglomerates, and (6) a dewatering step to recover the asbestos fibres.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the said solution comprises an aqueous medium.
Claim 4
Dependent Claim
25 words
A process according to claim 2 wherein the weight ratio of water to solids in the dispersion is in the range from 1:2 to 20:1.
Claim 5
Dependent Claim
25 words
A process according to claim 2 wherein the weight ratio of water to solids in the dispersion is in the range from 3:2 to 6:1.
Claim 6
Dependent Claim
18 words
A process according to claim 2 wherein the surfactant concentration in the aqueous phase is above 0.01% w/w.
Claim 7
Dependent Claim
18 words
A process according to claim 5 wherein the surfactant concentration in the aqueous phase is above 1% w/w.
Claim 8
Dependent Claim
23 words
A process according to claim 1 wherein the said surfactant is selected from the group consisting of anionic, non-ionic, cationic, and amphoteric surfactants.
Claim 9
Dependent Claim
54 words
A process according to claim 7 wherein the anionic surfactant is selected from the group consisting of carboxylates, N-acylsarcosinates, alkanesulphonates, linear and branched alkylarylsulphonates, dialkyl sulphosuccinates, arylsulphonates, naphthalenesulphonates, N-acyl-N-alkyllaurates, 2-sulphoethyl esters of fatty acids, olefin sulphonates, alkyl sulphates, sulphated natural oils, sulphated alkylphenol alkoxylates, and phosphate esters of alkanols and phenol and alkylphenol alkoxylates.
Claim 10
Dependent Claim
28 words
A process according to claim 8 wherein the anionic surfactants contain alkyl groups selected from the group consisting of nonyl, decyl, dodecyl, tridecyl, stearyl, cetyl, palmityl and myristyl.
Claim 11
Dependent Claim
47 words
A process according to claim 8 wherein the sulphosuccinates are selected from the group consisting of sodium dihexyl sulphosuccinate, sodium di(isobutyl)sulphosuccinate, sodium dioctylsulphosuccinate, magnesium dioctylsulphosuccinate, disodium N-octadecylsulphosuccinamate, tetrasodium N-(1,2-dicarbethoxyethyl)-N-octadecyl sulphosuccinamate, and the sodium sulphosuccinate esters of lauric mono- and di-ethanolamides or of ethoxylated lauryl or decyl alcohols.
Claim 12
Dependent Claim
21 words
A process according to claim 8 wherein the alkyarylsulphonates are selected from the group consisting of dodecylbenzenesulphonic acids and derivatives thereof.
Claim 13
Dependent Claim
37 words
A process according to claim 7 wherein the nonionic surfactant is selected from the group consisting of fatty acid esters, alkoxylated aliphatic alcohols and alkylphenols, alkoxylated fatty acids and fatty acid amides, and natural fats and oils.
Claim 14
Dependent Claim
25 words
A process according to claim 12 wherein the alkoxylates are ethoxylates containing from 1 to 50 ethyleneoxy (--CH 2 CH 2 --O--) units per molecule.
Claim 15
Dependent Claim
80 words
A process according to claim 13 wherein the aliphatic alcohols are selected from the group consisting of ethylene glycol, propylene glycol, glycerol, diethylene glycol, oleyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, tridecyl alcohol, myristyl alcohol, trimethylnonyl alcohol, primary C 12 C 13 and C 12 -C 15 alcohols, secondary C 11 -C 15 alcohols, tallow, sorbitan, and polyethylene glycol, and the alkylphenols are selected from the group consisting of nonylphenol, dodecylphenol, octylphenol, isooctylphenol, and C 8 -C 12 -alkyl-phenols.
Claim 16
Dependent Claim
47 words
A process according to claim 12 wherein the fatty acids are selected from the group consisting of lauric acid, stearic acid, oleic acid, coco acid, capric acid and myristic acid, ricinoleic acid, and acids derived from tall oil, soybean oil, rosin, tallow, lard, cottonseed, and safflower oil.
Claim 17
Dependent Claim
27 words
A process according to claim 12 wherein the amines used to prepare the fatty acid amides are selected from the group consisting of ethanolamine, diethanolamine, and isopropanolamine.
Claim 18
Dependent Claim
100 words
A process according to claim 7 wherein the cationic surfactant is selected from the group consisting of aliphatic mono-, di-, and poly-amines, amine salts, amine oxides of the general formula ##STR8## wherein A is hydrogen or hydroxyl, and R 1 is selected from the group consisting of cetyl, lauryl, myristyl, stearyl, coco, decyl, hexadecyl and octadecyl, alkoxylates of alkyl and alicyclic amines, 2-alkyl-1-(hydroxyethyl)-2-imidazolines, tetrakis-substituted ethylenediamines, amide-linked amines of the general formula ##STR9## wherein R 2 --CO--N is derived from the group consisting of coconut, oleic, stearic, and tall oil acids, and B is 2 or 3, and quaternary ammonium salts.
Claim 19
Dependent Claim
30 words
A process according to claim 17 wherein the alkoxylates of alkyl and alicyclic amines are ethoxylates of amines selected from the group consisting of coco-amine, soya-amine, tallow-amine, stearylamine, and resin.
Claim 20
Dependent Claim
30 words
A process according to claim 17 wherein the quaternary ammonium salts are selected from the group consisting of dialkyldimethylammonium salts, alkylbenzyl dimethylammonium salts, alkyltrimethylammonium salts, benzyltrimethylammonium salts, and alkylpyridinium salts.
Claim 21
Dependent Claim
24 words
A process according to claim 14 wherein the alkyl is selected from the group consisting of coco, tallow, soya, stearyl, cetyl, lauryl, and myristyl.
Claim 22
Dependent Claim
32 words
A process according to claim 7 wherein the amphoteric surfactant is selected from the group consisting of N-coco-3-aminopropionic acid, disodium N-lauryl-3-iminodipropionate, N-carboxymethyl-N-cocoalkyl-N,N-dimethylammonium hydroxide, the sodium salt of N-hydroxyethyl-N-lauromido-β-alanine, and substituted 2-imidazolinium hydroxides.
Claim 23
Dependent Claim
12 words
A process according to claim 7 wherein the surfactant comprises sodium dioctylsulphosuccinate.
Claim 24
Dependent Claim
12 words
A process according to claim 7 wherein the surfactant comprises dodecylbenzenesulphonic acid.
Claim 25
Dependent Claim
28 words
A process according to claim 7 wherein the surfactant comprises an ethoxylated amine prepared by the condensation of a C 17 diamine with 3 moles of ethylene oxide.
Claim 26
Dependent Claim
18 words
A process according to claim 7 wherein the surfactant comprises the nitrate salt of an ethoxylated amine prepared.
Claim 27
Dependent Claim
21 words
A process according to claim 1 wherein the temperature of the dispersion is in the range from ambient to 400° C.
Claim 28
Dependent Claim
18 words
A process according to claim 26 wherein the temperature is in the range from 50° to 200° C.
Claim 29
Dependent Claim
24 words
A process according to claim 1 wherein the concentration of surfactant in the diluted phase is in the range from 0.01 to 0.1% w/w.
Claim 30
Dependent Claim
16 words
A process according to claim 1 wherein the said asbestos-bearing material comprises low grade short fibre.
Claim 31
Dependent Claim
13 words
A process according to claim 1 wherein the said asbestos-bearing material is chrysotile.
Claim 32
Dependent Claim
26 words
A process according to claim 1 wherein the said asbestos-bearing material is subjected to wet crushing and grinding, optionally with classification, prior to the contacting step.
Claim 33
Dependent Claim
24 words
A process according to claim 31 wherein surfactant solution recovered from the slurry dilution step (3) is used in the wet crushing and grinding.
Claim 34
Dependent Claim
24 words
Stringy agglomerates of asbestos fibres prepared by the process of claim 1, the asbestos fibres being bonded together by said surfactant and said coagulation.
Claim 35
Dependent Claim
25 words
Stringy agglomerates of asbestos fibres according to claim 33 containing an amount of surfactant that is less than 20% w/w of the said asbestos fibres.
Claim 36
Dependent Claim
24 words
Stringy agglomerates of asbestos fibres of claim 34 wherein the said amount of surfactant is less than 10% w/w of the said asbestos fibres.
Claim 37
Dependent Claim
33 words
A process according to claim 1 wherein, in the slurry dilution step, the dispersion and diluent are sprayed simultaneously onto a screen mesh from a multiplicity of jets to recover the asbestos fibres.
Claim 38
Dependent Claim
19 words
A process according to claim 33 wherein the diluent used in the slurry dilution step is an aqueous medium.
Claim 39
Dependent Claim
16 words
A process according to claim 37 wherein the said aqueous medium contains a polymeric flocculating agent.
Claim 40
Dependent Claim
15 words
A process according to claim 37 wherein the said polymeric flocculating agent is a polyacrylamide.
Claim 41
Dependent Claim
22 words
A process according to claim 37 wherein the weight ratio of diluent to dispersion is in the range from 20:1 to 1500:1.
Claim 42
Dependent Claim
22 words
A process according to claim 29 wherein the weight ratio of diluent to dispersion is in the range from 70:1 to 400:1.
Claim 43
Dependent Claim
26 words
A process according to claim 36 wherein the asbestos-bearing material is treated prior to the contacting step with surfactant solution recovered from the slurry dilution step.
Claim 44
Dependent Claim
20 words
A process according to claim 51 wherein the recovered asbestos fibres are treated with a solution of an alkaline reagent.
References Cited (Backward Citations)
CA594371A
Cited
US1741869A
Cited
US1684365A
Cited
US1606281A
Cited
DE475040C
Cited
US1907616A
Cited
US2626213A
Cited
GB780619A
Cited
US3058591A
Cited
US3162380A
Cited
US3586639A
Cited
US3679542A
Cited
US3738805A
Cited
US3737333A
Cited
US3965284A
Cited
US3894692A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-07 | 1984-04-07 | 1984-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-07 | 1988-04-07 | 1988-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-07 | 1992-04-07 | 1992-10-07 | $7700.00 | Window Closed / Lapsed |