GB2268422A - Dewatering of mineral suspensions - Google Patents
Dewatering of mineral suspensions Download PDFInfo
- Publication number
- GB2268422A GB2268422A GB9314071A GB9314071A GB2268422A GB 2268422 A GB2268422 A GB 2268422A GB 9314071 A GB9314071 A GB 9314071A GB 9314071 A GB9314071 A GB 9314071A GB 2268422 A GB2268422 A GB 2268422A
- Authority
- GB
- United Kingdom
- Prior art keywords
- process according
- monomer
- polymer
- flocculant polymer
- sulphonate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910052500 inorganic mineral Inorganic materials 0.000 title claims abstract description 12
- 239000011707 mineral Substances 0.000 title claims abstract description 12
- 239000000725 suspension Substances 0.000 title claims abstract description 10
- 239000000178 monomer Substances 0.000 claims abstract description 30
- 229920000642 polymer Polymers 0.000 claims abstract description 22
- 125000000129 anionic group Chemical group 0.000 claims abstract description 17
- 229920001577 copolymer Polymers 0.000 claims abstract description 14
- 239000007787 solid Substances 0.000 claims abstract description 12
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000012141 concentrate Substances 0.000 claims abstract description 9
- QNIRRHUUOQAEPB-UHFFFAOYSA-N 2-(prop-2-enoylamino)butane-2-sulfonic acid Chemical compound CCC(C)(S(O)(=O)=O)NC(=O)C=C QNIRRHUUOQAEPB-UHFFFAOYSA-N 0.000 claims abstract description 6
- 159000000000 sodium salts Chemical class 0.000 claims abstract description 4
- 125000002091 cationic group Chemical group 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 15
- 239000000463 material Substances 0.000 claims description 11
- JXLHNMVSKXFWAO-UHFFFAOYSA-N azane;7-fluoro-2,1,3-benzoxadiazole-4-sulfonic acid Chemical compound N.OS(=O)(=O)C1=CC=C(F)C2=NON=C12 JXLHNMVSKXFWAO-UHFFFAOYSA-N 0.000 claims description 10
- 238000003756 stirring Methods 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 6
- 150000001412 amines Chemical class 0.000 claims description 4
- 238000005189 flocculation Methods 0.000 claims description 4
- 230000016615 flocculation Effects 0.000 claims description 4
- 239000000701 coagulant Substances 0.000 claims description 3
- 230000003311 flocculating effect Effects 0.000 claims description 3
- 125000001273 sulfonato group Chemical group [O-]S(*)(=O)=O 0.000 claims description 3
- -1 allyl sulphonate Chemical compound 0.000 claims description 2
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- NLVXSWCKKBEXTG-UHFFFAOYSA-N vinylsulfonic acid Chemical compound OS(=O)(=O)C=C NLVXSWCKKBEXTG-UHFFFAOYSA-N 0.000 claims description 2
- 229920006318 anionic polymer Polymers 0.000 claims 1
- 238000001914 filtration Methods 0.000 abstract description 5
- 239000000047 product Substances 0.000 description 25
- 235000012970 cakes Nutrition 0.000 description 15
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 description 5
- 239000003245 coal Substances 0.000 description 5
- 239000008394 flocculating agent Substances 0.000 description 5
- 229920001519 homopolymer Polymers 0.000 description 5
- 229920000768 polyamine Polymers 0.000 description 5
- 229940047670 sodium acrylate Drugs 0.000 description 5
- IRLPACMLTUPBCL-KQYNXXCUSA-N 5'-adenylyl sulfate Chemical compound C1=NC=2C(N)=NC=NC=2N1[C@@H]1O[C@H](COP(O)(=O)OS(O)(=O)=O)[C@@H](O)[C@H]1O IRLPACMLTUPBCL-KQYNXXCUSA-N 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 229920006317 cationic polymer Polymers 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000012065 filter cake Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000003760 tallow Substances 0.000 description 2
- 229920001897 terpolymer Polymers 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- DPBJAVGHACCNRL-UHFFFAOYSA-N 2-(dimethylamino)ethyl prop-2-enoate Chemical compound CN(C)CCOC(=O)C=C DPBJAVGHACCNRL-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- UFQHFMGRRVQFNA-UHFFFAOYSA-N 3-(dimethylamino)propyl prop-2-enoate Chemical compound CN(C)CCCOC(=O)C=C UFQHFMGRRVQFNA-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- 238000006683 Mannich reaction Methods 0.000 description 1
- NJSSICCENMLTKO-HRCBOCMUSA-N [(1r,2s,4r,5r)-3-hydroxy-4-(4-methylphenyl)sulfonyloxy-6,8-dioxabicyclo[3.2.1]octan-2-yl] 4-methylbenzenesulfonate Chemical compound C1=CC(C)=CC=C1S(=O)(=O)O[C@H]1C(O)[C@@H](OS(=O)(=O)C=2C=CC(C)=CC=2)[C@@H]2OC[C@H]1O2 NJSSICCENMLTKO-HRCBOCMUSA-N 0.000 description 1
- 229920006322 acrylamide copolymer Polymers 0.000 description 1
- 150000003926 acrylamides Chemical class 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000003250 coal slurry Substances 0.000 description 1
- 239000000084 colloidal system Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 125000004985 dialkyl amino alkyl group Chemical group 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 235000021463 dry cake Nutrition 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- SKMHHHHLLBKNKR-UHFFFAOYSA-M sodium;prop-2-enamide;prop-2-enoate Chemical compound [Na+].NC(=O)C=C.[O-]C(=O)C=C SKMHHHHLLBKNKR-UHFFFAOYSA-M 0.000 description 1
- UZNHKBFIBYXPDV-UHFFFAOYSA-N trimethyl-[3-(2-methylprop-2-enoylamino)propyl]azanium;chloride Chemical compound [Cl-].CC(=C)C(=O)NCCC[N+](C)(C)C UZNHKBFIBYXPDV-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/12—Treatment of sludge; Devices therefor by de-watering, drying or thickening
- C02F11/121—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering
- C02F11/123—Treatment of sludge; Devices therefor by de-watering, drying or thickening by mechanical de-watering using belt or band filters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D37/00—Processes of filtration
- B01D37/03—Processes of filtration using flocculating agents
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
- C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Separation Of Suspended Particles By Flocculating Agents (AREA)
Abstract
An aqueous mineral concentrate having a solids content of 200 to 600 grams per litre is flocculated with a polymeric anionic flocculant formed from ethylenically unsaturated monomers comprising sulphonic monomer and the flocculated suspension is dewatered by means of a pressure belt filter. The flocculant type used appears to give a floc structure that is particularly suited to pressure belt filtration. A preferred anionic flocculant polymer is a copolymer of the sodium salt of acrylamido methyl propane sulphonic acid (AMPS) and acrylamide. Preferred flocculant polymers have intrinsic viscosity of at least 8dl/g.
Description
Allied Colloids Limited
Dewatering of Suspensions and Polymers for Use in This
Anionic flocculants are widely used for flocculating mineral suspensions. The flocculated suspensions are often dewatered by sedimentation. The normal flocculants are polymers of sodium acrylate, but the use of sulphonate polymers is known (e.g., U.S. 4,342,653 and 4,704,209). In
U.S. 4,647,382 a sulphonate polymer is used to make a redispersible cake, but since the cake is redispersible the polymer must be of low molecular weight relative to high molecular weight flocculants.
A particular problem arises when it is desired to dewater an aqueous mineral concentrate having a solids content of 200-600g/l by mixing it with a polymeric flocculant to cause flocculation followed by dewatering it under pressure and shear on a pressure belt filter. This leads to the production of a substantially dry cake that can be removed from the filter.
This process is widely used on coal based slurries, barrel wash effluents, tailings, coal slurries, screen underflows, etc. but it is also used for sand effluents, limestone effluents, china clay, calcium carbonate and the other mineral substrates.
The requirements are that rapid dewatering of the slurry takes place such that sufficient free water is removed prior to pressure being applied when the pressure belts come together. Further dewatering takes place in the pressure zone and as the belts part the filter cake should easily fall away from the cloths. The filter cake usually has a moisture content of 25-45% w/w.
The polymeric flocculant that is conventionally used in such processes in which dewatering takes place ona pressure belt filter is a high molecular weight non-ionic or anionic acrylamide copolymer, i.e., a substantial homopolymer of polyacrylamide or a copolymer of sodium acrylate with acrylamide, or sometimes sodium acrylate homopolymer.
The use of this flocculant tends to give rather large flocs that can cause blinding of the filtration belts or cloths.
It is known to mix into the flocculated system relatively low molecular weight cationic polymers so as to strengthen the flocs and facilitate the separation of the flocculated material from the pressure belts.
According to the invention, we find a better performance can be obtained if the flocculant has high molecular weight and contains sulphonate groups. It seems that this flocculant type gives a floc structure that is particularly suited to pressure belt filtration.
A process according to the invention for dewatering an aqueous mineral concentrate having a solids content of 200600g/l comprises flocculating the concentrate with an anionic flocculant polymer formed from ethylenically unsaturated monomers comprising sulphonic monomer, and dewatering the flocculated suspension by means of a pressure belt filter. It can be a conventional pressure belt filtration system for dewatering aqueous mineral suspensions that have previously been flocculated by use of an acrylamide-sodium acrylate copolymer. Typical pressures during a conventional pressure belt filtration cycle are at least lpsi, preferably at least 1.5psi, more preferably at least 3psi, and can be up to 30psi and above in the later stages of the cycle.
The flocculant polymer is formed from ethylenically unsaturated monomers comprising a monomer that includes sulphonic groups, preferably sulphonate groups. The preferred sulphonate monomer is acrylamido methyl propane sulphonic acid (AMPS, U.S. trade mark) or salts thereof but other sulphonate monomers can, less preferably, be used.
Examples include vinyl sulphonate and allyl sulphonate (but it is necessary to ensure that the flocculant has adequate molecular weight).
The polymer is generally a copolymer of sulphonate monomer with other monomer. The other monomer may be anionic or non-ionic or a blend. The monomers are usually all water soluble. A preferred comonomer is acrylamide and so preferred copolymers for use in the invention are copolymers of sulphonate monomer (generally AMPS) and acrylamide.
Additional monomer can be used for forming the copolymer, and in particular terpolymers with an ethylenically unsaturated carboxylic acid monomer, especially acrylic acid (usually as sodium acrylate) can be used.
The copolymers are generally formed from a monomer mixture containing 5 to 95%, preferably 10 to 60%, often 20 to 40%, sulphonate monomer, preferably the sodium salt of
AMPS. The mixture generally contains from 5 to 95%, preferably 30 to 70%, often 40 to 60%, by weight acrylamide. The mixture may also contain from 10 to 50%, preferably 15 to 35%, by weight carboxylic monomer, for instance sodium acrylate.
The polymer preferably has intrinsic viscosity above 8, most preferably above lOdl/g. It is usually unnecessary for it to have intrinsic viscosity above about 25dl/g, but higher values can be used if desired.
Intrinsic viscosity is measured by suspended level viscometer in buffered 1N NaCl at 250C.
The polymer may be made by conventional techniques, for instance gel polymerisation or reverse phase emulsion or bead polymerisation.
We find the use of the AMPS copolymer or terpolymer gives a stronger floc structure than is obtainable with the conventional sodium acrylate-acrylamide flocculants. This improved floc structure reduces the risk of blinding of the belts or other filter elements and allows the attainment of a lower moisture content in the dewatered product.
As a result of the use of the sulphonate monomer, it may be possible to achieve adequate results without the need for subsequent dosing with low molecular weight cationic material, especially if the aqueous dispersion that has been treated with the sulphonate anionic flocculant is subjected to vigorous stirring before cake formation so as to degrade the flocs. However it is generally preferred to flocculate the aqueous mineral suspension with the defined sulphonate flocculant and then to treat the flocculated suspension, often after shearing or other stirring to break down the floc size; with a low molecular weight cationic material. This material has lower molecular weight than the flocculant. It can be a cationic polymer which can be any of the materials that are conventionally regarded as low molecular weight cationic coagulants.Typically they have intrinsic viscosity below 4dl/g, often below 2dl/g and may have molecular weight typically below 1 million. Suitable materials are polyamines, homopolymers of diallyl dimethyl ammonium chloride and copolymers of it with acrylamide (usually in a minor amount) and homopolymers (or copolymers with acrylamide) of dialkylaminoalkyl -(meth) acrylates or (meth) acrylamides. For instance suitable polymers are
Mannich reaction products and homopolymers (or copolymers with acrylamide) of quaternised dimethylaminoethyl acrylate or dimethylaminopropyl acrylate (e.g., MAPTAC).
Instead of using a cationic polymer, a monomeric precipitant can be used. Examples are fatty amines, generally in quaternised salt form. An example is quaternary tallow amine.
The dosage of the flocculant (and also the dosage of the cationic material if used) is generally in the range 50 to 600g/tds. The ratio of flocculant to cationic material (if used) is generally in the range 100:0 to 50:50.
The following are examples of the invention.
Example 1
A coal screen underflow of following characteristics was used as substrate.
35.1% w/v solids (weight (g) by volume (1)) 30.1% Ash (on solids) 62.4%-63# (on solids) pH - 7.0
400cm3 samples of substrate were taken in 600cm beakers and stirred mechanically using a gate stirrer. The anionic flocculant was added at 213g/tds (grammes/ton dry solids) stirring continued for 8-10 seconds. The flocculated sample was transferred to the chamber of the belt press simulator and allowed to dewater for 45 seconds.
The top belt was lowered on to the semi-formed cake and a pressure cycle as follows applied.
Pressure Cycle:
Time (Sec) Pressure (nisi) 0-15 3
15-30 6
30-45 9
45-53 12
53-60 18
60-68 24
The moisture content of the resultant cake was measured.
Product A = 30:70 NaAc:ACM IV = 12
B = 40:60 NaAMPS:ACM IV = 17
C = 20:20:60 NaAc:NaAMPS:ACM IV = 16
D -= 20:30:50 NaAc:NaAMPS:ACM IV = 19
E = 30:20:50 NaAc:NaAMPS:ACM IV = 20
The following cake moisture contents were obtained.
A = 35.3%
B = 33.8%
C = 34.0%
D = 34.5%
E = 34.3%
ExamPle 2
The same slurry as in 1 was used. In this case after the anionic flocculant had been added mixing was continued for 10 seconds. A cationic polyamine of IV approx 0.3 was then added at an active dose of 213g/tds and mixing continued for 2 seconds. The following cake moisture contents were obtained.
Product A - 35.2%
Product B - 34.8%
Example 3
Coal screen underflow as in Example 1 was used.
Anionic flocculant was added at 213g/t and stirring continued for 10-22 sec. Cationic polyamine as in Example 2 was added at the ative dose level quoted and mixing continued for 2-3 seconds. The sample was treated as in
Example 1.
Cationic Active Cake Moisture Content % Dose git Product A Product B 213 34.8 34.1 142 34.4 34.6 71 34.5 34.2 35.5 34.6 33.8 14 Cake broke down 33.9 Product B maintains an improved performance as the sose of cationic product decreases.
Example 4
Coal screen underflow as in Example 1 was used.
Anionic flocculant was added at 213g/t and stirring continued for 10-14 seconds. Cationic polyamine as in
Example 2 was added at 213g/t and mixing continued for 2-3 seconds. The test parameters used were varied as follows: (i) Volume of sample (ii) Pressure cycle
Volume A = 400cm3
Volume B = 600cm3 Volume C = 800cm3
Cycle A = that quoted in Example 1.
Time (Sec.) Pressure Cycle B Cycle C Cycle D 3 0-30 0-45 0-60 6 30-60 45-90 60-120 9 60-90 90-135 120-180 12 90-106 135-158 180-210 18 106-120 158-180 210-240 24 120-136 180-203 240-270
Cycle E is the same as Cycle B but 24psi is maintained until no further dewatering is observed.
Volume Cycle Cake Moisture Content Product A Product B A B 34.7 34.2 A E 34.1 33.3 B A 35.5 34.1 C A 36.5 35.5 B C 34.7 32.9 C D 33.0 32.2 Under all the conditions evaluated Product B provides improved moistures over Product A.
Example 5
A sample of coal screen underflow from the same plant as that used in Example 1 was the test substrate but it had slightly different characteristics as follows.
38.1% w/v solids 33.7% Ash (on solids) 54.0% -63y (on solids) pH - 7.0
Tests were carried out as described in Example 1 except that anionic flocculant was added at a dose level of 198t/tds and stirring maintained for between 20 and 25 seconds. Cationic polyamine was added as in Example 2 at the dose levels quoted and mixing continued for 2-3 seconds.
Anionic flocculants test: Product B
Product C
Product F 30:70 NaAc:ACM IV = 23.
Cationic Cake Moisture Content (%) Active Dose (g/tds) Product B Product C Product F 198 32.6 32.6 33.3 132 32.1 32.9 33.9 66 32.1 - 33.3 33 31.4 - 13 - - The products containing sodium AMPS provide productsan improvement in moisture content.
Example 6
Tests as described in Example 5 were carried out using
Products A & B. In this case the cationic component used was quaternary tallow amine, generally less effective than the polymeric cationic coagulants normally used.
Active Dose of Cake Moisture Content % Cationic Product Product A Product B 198 33.3 32.1 132 Cake Broke Down 31.5 66 Did not press 31.5 33 Did not press Cake Broke Down 17 Did not press Did not press Even with a less effective cationic component Product
B continues to work with a lower cationic dose and provides cakes of lower moisture content than Product A.
Claims (13)
1. A process for dewatering an aqueous mineral concentrate having a solids content of 200 to 600 grams per litre comprising flocculating the concentrate with an anionic flocculant polymer formed from ethylenically unsaturated monomers comprising sulphonic monomer, and dewatering the flocculated suspension by means of a pressure belt filter.
2. A process according to claim 1, wherein the anionic flocculant polymer has an intrinsic viscosity of at least 8dl/g.
3. A process according to claim 1 or claim 2, wherein the anionic flocculant polymer is formed from ethylenically unsaturated monomers comprising a monomer that includes sulphonate groups.
4. A process according to any preceding claim, wherein the sulphonic monomer is acrylamido methyl propane sulphonic acid (AMPS) or its sodium salt or vinyl sulphonate or allyl sulphonate, preferably AMPS or its sodium salt.
5. A process according to any preceding claim, wherein the flocculant polymer is a copolymer of sulphonic monomer and acrylamide.
6. A process according to any preceding claim, wherein the polymer is formed from a monomer mixture containing 10 to 60%, preferably 20 to 40%, sulphonate monomer.
7. A process according to claim 5, wherein the copolymer is formed from a monomer mixture containing 30 to 70%, preferably 40 to 60%, acrylamide monomer.
8. A process according to any preceding claim, wherein the flocculant polymer has an intrinsic viscosity from 10 to 25dl/g.
9. A process according to any preceding claim, wherein after flocculation with the anionic flocculant polymer the aqueous mineral concentrate is subjected to vigorous stirring before cake formation.
10. A process according to any preceding claim, wherein after flocculation with the anionic flocculant polymer the aqueous mineral concentrate is treated with a cationic material having lower molecular weight than the flocculant polymer.
11. A process according to claim 10, wherein the cationic material is a cationic coagulant having intrinsic viscosity below 4dl/g.
12. A process according to claim 10, wherein the cationic material is a monomeric precipitant, preferably a quaternised fatty amine.
13. Use of an anionic polymer formed from ethylenically unsaturated monomers comprising sulphonic monomer to flocculate an aqueous mineral concentrate having a solids content of 200 to 600 grams per litre which is to be dewatered subsequent to flocculation, said dewatering being carried out by means of a pressure belt filter.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB929214517A GB9214517D0 (en) | 1992-07-08 | 1992-07-08 | Dewatering of suspensions and polymers for use in this |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9314071D0 GB9314071D0 (en) | 1993-08-18 |
| GB2268422A true GB2268422A (en) | 1994-01-12 |
| GB2268422B GB2268422B (en) | 1995-11-01 |
Family
ID=10718403
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB929214517A Pending GB9214517D0 (en) | 1992-07-08 | 1992-07-08 | Dewatering of suspensions and polymers for use in this |
| GB9314071A Expired - Fee Related GB2268422B (en) | 1992-07-08 | 1993-07-08 | Dewatering of suspensions and polyners for use in this |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB929214517A Pending GB9214517D0 (en) | 1992-07-08 | 1992-07-08 | Dewatering of suspensions and polymers for use in this |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB9214517D0 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2339425A (en) * | 1998-07-11 | 2000-01-26 | Clearmasters Environmental Lim | De-watering apparatus |
| RU2185225C2 (en) * | 1999-06-07 | 2002-07-20 | Акционерное общество открытого типа "Челябинский электролитный цинковый завод" | Method of separation of solution from solids for process products |
| US7566469B2 (en) * | 2003-10-13 | 2009-07-28 | Nalco Company | Method of dewatering grain stillage solids |
| CN102690002A (en) * | 2012-06-15 | 2012-09-26 | 湖州新开元碎石有限公司 | Solid-liquid separation method for tailing disposal |
| CN110215763A (en) * | 2014-02-26 | 2019-09-10 | 艺康美国股份有限公司 | The substitution additive of strengthening slurry dehydration |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4792406A (en) * | 1988-05-23 | 1988-12-20 | Nalco Chemical Company | Method for dewatering a slurry using a twin belt press with cationic amine salts |
-
1992
- 1992-07-08 GB GB929214517A patent/GB9214517D0/en active Pending
-
1993
- 1993-07-08 GB GB9314071A patent/GB2268422B/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4792406A (en) * | 1988-05-23 | 1988-12-20 | Nalco Chemical Company | Method for dewatering a slurry using a twin belt press with cationic amine salts |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2339425A (en) * | 1998-07-11 | 2000-01-26 | Clearmasters Environmental Lim | De-watering apparatus |
| RU2185225C2 (en) * | 1999-06-07 | 2002-07-20 | Акционерное общество открытого типа "Челябинский электролитный цинковый завод" | Method of separation of solution from solids for process products |
| US7566469B2 (en) * | 2003-10-13 | 2009-07-28 | Nalco Company | Method of dewatering grain stillage solids |
| CN102690002A (en) * | 2012-06-15 | 2012-09-26 | 湖州新开元碎石有限公司 | Solid-liquid separation method for tailing disposal |
| CN110215763A (en) * | 2014-02-26 | 2019-09-10 | 艺康美国股份有限公司 | The substitution additive of strengthening slurry dehydration |
| CN110215763B (en) * | 2014-02-26 | 2021-06-15 | 艺康美国股份有限公司 | Alternative additives to enhance slurry dewatering |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9314071D0 (en) | 1993-08-18 |
| GB2268422B (en) | 1995-11-01 |
| GB9214517D0 (en) | 1992-08-19 |
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| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20030708 |