AU669284B2 - Use of hydroxamic acid containing polymers to improve filtration of settler overflow in Kelly filters in the Bayer process - Google Patents
Use of hydroxamic acid containing polymers to improve filtration of settler overflow in Kelly filters in the Bayer process Download PDFInfo
- Publication number
- AU669284B2 AU669284B2 AU63246/94A AU6324694A AU669284B2 AU 669284 B2 AU669284 B2 AU 669284B2 AU 63246/94 A AU63246/94 A AU 63246/94A AU 6324694 A AU6324694 A AU 6324694A AU 669284 B2 AU669284 B2 AU 669284B2
- Authority
- AU
- Australia
- Prior art keywords
- polymer
- slurry
- settler overflow
- bayer process
- settler
- 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.)
- Withdrawn - After Issue
Links
- 229920000642 polymer Polymers 0.000 title claims description 42
- 238000001914 filtration Methods 0.000 title claims description 33
- 239000002253 acid Substances 0.000 title claims description 16
- NEAQRZUHTPSBBM-UHFFFAOYSA-N 2-hydroxy-3,3-dimethyl-7-nitro-4h-isoquinolin-1-one Chemical compound C1=C([N+]([O-])=O)C=C2C(=O)N(O)C(C)(C)CC2=C1 NEAQRZUHTPSBBM-UHFFFAOYSA-N 0.000 title claims description 14
- 238000004131 Bayer process Methods 0.000 title claims description 14
- 238000000034 method Methods 0.000 claims description 18
- 239000002002 slurry Substances 0.000 claims description 18
- 239000007787 solid Substances 0.000 claims description 14
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 6
- 239000000920 calcium hydroxide Substances 0.000 claims description 6
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 6
- 235000011116 calcium hydroxide Nutrition 0.000 claims description 6
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 5
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 5
- 239000004571 lime Substances 0.000 claims description 5
- 150000003839 salts Chemical group 0.000 claims description 5
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 claims description 4
- 229920003169 water-soluble polymer Polymers 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 2
- 239000003643 water by type Substances 0.000 claims description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 9
- 239000003795 chemical substances by application Substances 0.000 description 9
- 239000000706 filtrate Substances 0.000 description 8
- 229920002307 Dextran Polymers 0.000 description 6
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 4
- 229910001388 sodium aluminate Inorganic materials 0.000 description 4
- 229910001570 bauxite Inorganic materials 0.000 description 3
- 229920000058 polyacrylate Polymers 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 229940048053 acrylate Drugs 0.000 description 2
- 239000003518 caustics Substances 0.000 description 2
- 238000009533 lab test Methods 0.000 description 2
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229920001897 terpolymer Polymers 0.000 description 2
- 150000004684 trihydrates Chemical class 0.000 description 2
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-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
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- AVXURJPOCDRRFD-UHFFFAOYSA-N Hydroxylamine Chemical compound ON AVXURJPOCDRRFD-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- 229920001410 Microfiber Polymers 0.000 description 1
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-N Propionic acid Chemical class CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 125000005250 alkyl acrylate group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- -1 alkyl methacrylates Chemical class 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 238000005352 clarification Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 235000013312 flour Nutrition 0.000 description 1
- ZZUFCTLCJUWOSV-UHFFFAOYSA-N furosemide Chemical compound C1=C(Cl)C(S(=O)(=O)N)=CC(C(O)=O)=C1NCC1=CC=CO1 ZZUFCTLCJUWOSV-UHFFFAOYSA-N 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 150000003840 hydrochlorides Chemical class 0.000 description 1
- 150000002443 hydroxylamines Chemical class 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical compound CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 description 1
- 239000003658 microfiber Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical class OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229940047670 sodium acrylate Drugs 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical class [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000002562 thickening agent Substances 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
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
1
AUSTRALIA
PATENTS ACT 1990 CO M P T. R T R SPECIPT -7TSq 1 Z T
Y~~LI~~IIV~
FOR A STANDARD PATENT
ORIGINAL
*o i Name of Applicant: Actual Inventor: Address for Service: Invention Title: NALCO CHEMICAL COMPANY Robert P. MAHONEY SHELSTON WATERS Clarence Street SYDNEY NSW 2000 "USE OF HYDROXAMIC ACID CONTAINING POLYMERS TO IMPROVE FILTRATION OF SETTLER OVERFLOW IN KELLY FILTERS IN THE BAYER PROCESS" o r o f r The following statement is a full description of this invention, including the best method of performing it known to us:la USE OF HYDROXAMIC ACID CONTAINING POLYMERS TO IMPROVE FILTRATION OF SETTLER OVERFLOW IN KELLY FILTERS IN THE BAYER PROCESS Field of the Invention The present invention relates generally to methods for improving the filtration of a settler overflow stream obtained in the Bayer process. This invention particularly relates to addition of a hydroxamic acid containing polymer to the settler overflow and filter aid to improve filtration rate.
.Background of the Invention Alumina is commonly recovered from bauxite ore by means of the Bayer process.
The process involves digestion of bauxite with a caustic solution to form a slurry of 10 sodium aluminate solution and suspended solids. The suspended solids are separated from •the solution by subjecting the solution to one or more separation procedures to produce a settler overflow stream. The stream is further clarified by filtration to improve the purity of the resultant alumina.
During the Bayer process, the bauxite ore and caustic solution aie mixed to form a slurry which flows through a series of digesters at elevated temperature and pressure to extract alumina from the ore. The aluminate effluent from the digesters is cooled and returned to atmospheric pressure. The effluent consists of a slurry of sodium aluminate solution and an insoluble red mud fraction. Although the coarse red mud particles can be readily removed using conventional separation techniques, the finer particles must be treated with a flocculant to effect separation. The flocculant causes the red mud to settle 2 and form a concentrated red mud pulp. The red mud pulp is removed from the settler and washed for recovery of sodium aluminate.
The superate from the settler is a clarified sodium aluminate solution commonly referred to as the settler overflow or thickener overflow. The settler overflow solution is further clarified by addition of a filter aid and subsequent filtration using Kelly filter presses, producing a filtrate having a low amount of suspended solids. Alumina trihydrate crystals are then precipitated from the filtrate while the remaining solution is recycled to the digesters.
Various filter aids have been selected to improve the filtration of settler overflow.
The predominant practice in the alumina industry is _ddition of a filter aid such as slaked lime, lime solids, or calcium aluminate to the settler overflow. Addition of these filter 1 aids, however, reduces the rate of filtration of the settler overflow solution. The filtration rate of settler overflow treated with a filter aid has been improved by adding dextran to the solution as described in U.S. Patent No. 5,091,159. U.S. Patent No. 4,789,485 discloses the use of quaternized polymers such as 3-(methacrylamido)propyl trimethyl ammonium chloride to improve filtration rate and clarity of settler overflow.
Polymers containing pendant hydroxamic acid groups are described as improving the removal of suspended solids from Bayer process streams in U.S. Patent No.
o4,767,540. The polymers are added to the settler feed, settler overflow, or digester blowoff either alone, in addition to, or in combination with an anionic flocculant selected from a starch, flour, or a polyacrylate.
There is a need for more effective treating agents which can improve filtration rate of settler overflow, reduce the amount of filter aid required for settler overflow clarification, and improve filtrate clarity.
Summary of the Invention According to a first aspect of the invention, there is provided a method of filtering a settler overflow slurry obtained in a Bayer process, wherein the method comnprises the steps of: providing a settler overflow slurry containing suspended solids and a filter aid; admixing the slurry with an amount of a water-soluble polymer having hydorxamic acid groups or hydroxamic acid salt groups effective in improving filtration rate of the slurry; and filtering-the suspended solids and filter aid from the slurry.
In order to satisfy the need for an effective treating agent which improves the filtration rate of a settler overflow solution treated with a filter aid, one aspect of the present invention provides a method of filtering a settler overflow slurry obtained in a Bayer process. A settler overflow slurry containing suspended solids and a filter aid is provided. The slurry is admixed with an amount of a water-soluble polymer having hydroxamic acid or salt groups effective in increasing filtration rate of the slurry. The effective amount of the polymer typically ranges from about 0.01 to about 30mg/l, more 15 preferably from about 0.1 to about 10 mg/1. The polymer preferably has a molecular weight of from about 10,000 to about 30 million and a degree of hydroxamation of from about 1 to about 90 mole percent. Lime solids, slaked lime, or calcium aluminate are conventional filter aids for settler overflow treatment.
It is an object of this invention to provide a treating agent for improving the rate of filtration of the settler overflow solution treated with a filter aid.
It is another object of this invention to provide a method for reducing the amount of filter aid which is required for filtration of settler overflow to reduce filtration cost.
-4- Addition of the hydroxamated polymer also improves the clarity of the filtrate to improve the quality of the alumina trihydrate product.
Other objects will be apparent to those skilled in the art from the disclosure herein.
Detailed Description of the Invention The present invention provides a method for improving the filtration rate of a settler overflow solution treated with a filter aid. An effective amount of the hydroxamated polymer treating agent of the present invention is added to the solution.
An effective amount of the treating agent is an amount sufficient to increase the filtration rate of the settler overflow solution before it is subjected to a Kelly filter press to polish the solution. The increased filtration rate of the solution after addition of the hydroxamated polymer results in greater production of alumina. Additionally, the amount of suspended solids such as iron and calcium containing minerals is reduced by adding the treating agent of the present invention, providing a filtrate having improved clarity. The filtrate, when further treated, produces alumina which contains a lower level 15 of contaminants than would alumina produced by the Bayer process without addition of a hydroxamated polymer. The method of the present invention also allows for the use of less filter aid resulting in longer cycle times in Kelly filter presses.
The hydroxamated polymer treating agent of the present invention can be added to the settler overflow solution prior to or after addition of a filter aid to the solution. The proper dosage of the treating agent preferably ranges from about 0.01 to about 30 mrng of a hydroxamated polymer per liter of settler overflow solution. The more preferred dosage of the hydroxamated polymer is from about 0.1 to about 10mg/l. The hydroxamated polymer is preferably added to the solution after it has been treated with a filter aid. Filter aids which are typically used in treating settler overflow prior to subjecting the solution to a filter press include slaked lime, lime solids and calcium aluminate. The dosage of filter aid which is added to the settler overflow is well known in the art.
The hydroxamated polymer treating agent can be any water soluble polymer containing pendant hydroxamic acid or salt groups. Such polymers are well known in the art and are described in U.S. Patent Nos. 4,587,306, 4,767,540, 4,868,248, 4,902,751, and 5,128,420 which are incorporated herein by reference. Hydroxamated polymers are generally formed by reaction of a polymer containing pendant reactive groups with hydroxylamine or its salt for several hours at a temperature of from about 20 0 C to about 150°C. The degree ofhydroxamation in the resultant polymers ranges from about 1 to about 90 mole percent. Suitable hydroxylamine salts include sulfates, sulfites, phosphates, hydrochlorides, perchlorates, propionates and acetates. Polymers which may be hydroxamated for purposes of the present invention are homopolymers, 15 copolymers, terpolymers, etc. of monomers including acrylic acid, alkyl acrylates, a sodium acrylate, methacrylic acid, alkyl methacrylates, alkyl crotonates, maleic anhydride, maleic anhydride esters, acrylonitrile, acrylamide, methacrylamide, vinyl acetate, vinyl pyrrolidone, butadiene, styrene and other acid ester, nitrile, and amide polymers.
The following examples are presented to describe preferred embodiments and utilities of the present invention and are not meant to limit the present invention unless otherwise stated in the claims appended hereto.
d e e *e oooo *e k Examples 1 3 A 250 ml sample of a settler overflow liquor obtained from a Bayer process refinery was heated to 100 0 C. A filtration apparatus was fitted with a microfiber filter paper and maintained at 25.4 cm (10 inches) of mercury vacuum. The liquor was filtered and the amount of time required for all of the liquid to filter was recorded and converted to a filtration-rate as shown below in example 1.
Two additional 250 ml samples of the liquor were obtained and maintained at 100 0 C. The samples were then treated with 2.0 g/1 slaked lime solids and mixed thoroughly. A hydroxamated polymer was added to each of the two samples in an amount of 3.2g/1 and 4.8 g/l, respectively. The hydro:amated polymer used in examples 2 and 3 is a high molecular weight terpolymer of an acrylate salt, a hydroxamic acid group and acrylamide in the approximate molar ratio of 65:15:20, respectively. The reduced specific viscosity of the polymer determined with standard viscometer 15 equipment is about 24 dl/g. The samples were filtered as described above for the untreated liquor. The relative filtration rates of the treated liquors are summarized below: 1 None 0 2 Hydroxamated Polymer 3.2 1.22 3 Hydroxamated Polymer 4.8 1.52 In example 1, the filtration rate of the overflow liquor was reduced through the addition of the slaked lime filter aid. However in examples 2 and 3, addition of the same amount of the filter aid followed by addition of the hydroxamated polymer improved the filtration rate by as much as 52%.
Example 4 A laboratory test was performed to compare the effectiveness of hydroxamic acid containing polymers of the invention with dextran on performance of Kelly Filters in the Bayer process. A laboratory scale (350 ml capacity) pressure filter was fitted with filter cloth used in Kelly Filters, then settler overflow was mixed with filter aid (lime) and polymer and filtered at The hydroxamic acid polymer was more effective than dextran or acrylate polymer at improving the turbidity of filtrate as shown in the Table below. With no polymer additive the turbidity was 21 NTU and the hydroxamated polymer reduced turbidity by 63% (8 NTU) without slowing filtration rate. Dextran did not improve 15 turbidity as much as the hydroxamated polymer. Polyacrylate improved filtrate turbidity by 57% but slowed filtration rate significantly.
TABLE
KELLY FILTER LAB TEST RESULTS Filtration Rate (ml/min) at Dosage of: Polymer 0 mg/L 0.2 mg/L 0.4 mg/L 2.0 mg/L dextran 509 474 569 505 hydroxamic acid 509 510 446 304 acrylate 509 386 354 154 Polymer dextran hydroxamic acid acrylate Turbidity (NTU) at Dosage of: 0 mg/L 0.2 mg/L 0.4 mg/L 21 20 15 21 7.8 7.9 21 9.0 8.7 2.0 mg/L 12 8.3 13
S
S
Starting turbidity 390 NTU While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example and were herein described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Claims (2)
- 2. The method of claim 1 wherein from about 0.01 to about 30 mng/I of the polymer is admixed with the slurry. t0 3. The method of claim I or 2 wherein from about 0. 1 to about 10) mg/I of the polymer is admixed with the slurry. The method of any one of claims I to 3 wherein the polymer has a molecular weight from 10,000 to 30 million. The method of any one of claims 1 to 4 wherein the polymer has a degree of hydroxamation of from I to 90 mole percent. The method of any one of claims 1 to 5 wherein the filter aid is selected from the group consisting of lime solids, slaked lime and calcium aluminate.
- 7. A method of filtering a settler overflow in a Bayer process, which method is substantially as herein described with reference to Example 2 or 3. DATED this 27th day of Mlarch, 1996 NALCO CHEMICAL COMPANY Attorney: RUTH M. CLARKSON Fellow Institute of Patent Attorneys of Australia of SHELSTON WATERS Abstract of the Invention A method of filtering a settler overflow slurry obtained in a Bayer process is described. A settler overflow slurry containing suspe.,Jed solids and a filter aid is provided. The slurry is admixed with an amount of a water-soluble polymer having hydroxamic acid or salt groups effective in improving filtration rate of the slurry. ea. oo* o
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US7129193A | 1993-06-02 | 1993-06-02 | |
| US071291 | 1993-06-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU6324694A AU6324694A (en) | 1994-12-08 |
| AU669284B2 true AU669284B2 (en) | 1996-05-30 |
Family
ID=22100422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU63246/94A Withdrawn - After Issue AU669284B2 (en) | 1993-06-02 | 1994-05-20 | Use of hydroxamic acid containing polymers to improve filtration of settler overflow in Kelly filters in the Bayer process |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU669284B2 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4767540A (en) * | 1987-02-11 | 1988-08-30 | American Cyanamid Company | Polymers containing hydroxamic acid groups for reduction of suspended solids in bayer process streams |
| AU667390B2 (en) * | 1992-09-14 | 1996-03-21 | Nalco Chemical Company | Trihydrate clarification aid for the bayer process |
| AU668029B2 (en) * | 1993-05-07 | 1996-04-18 | Nalco Australia Pty. Limited | Bayer process Do not seal seling fee to be refunded |
-
1994
- 1994-05-20 AU AU63246/94A patent/AU669284B2/en not_active Withdrawn - After Issue
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4767540A (en) * | 1987-02-11 | 1988-08-30 | American Cyanamid Company | Polymers containing hydroxamic acid groups for reduction of suspended solids in bayer process streams |
| AU667390B2 (en) * | 1992-09-14 | 1996-03-21 | Nalco Chemical Company | Trihydrate clarification aid for the bayer process |
| AU668029B2 (en) * | 1993-05-07 | 1996-04-18 | Nalco Australia Pty. Limited | Bayer process Do not seal seling fee to be refunded |
Also Published As
| Publication number | Publication date |
|---|---|
| AU6324694A (en) | 1994-12-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6086771A (en) | Water continuous emulsion polymers for improving scale control in the bayer process | |
| AU699929B2 (en) | Removing suspended solids by addition of hydroxamated polymers in the Bayer Process | |
| AU578544B2 (en) | Clarification of bayer process liquors | |
| US6726845B1 (en) | Dextran starch and flocculant combination for improving red mud clarification | |
| CA2366450C (en) | Process for purifying bayer process streams | |
| US5346628A (en) | Polymers for flocculating red mud from bayer process liquors | |
| US5520820A (en) | Process for flocculating suspended solids | |
| US6048463A (en) | Water continuous methyl acrylate emulsion polymer combinations and methyl acrylate emulsion homopolymers for improved flocculation of red mud in the bayer process | |
| EP0602900A1 (en) | Trihydrate crystal modification in the bayer process | |
| OA10765A (en) | Concentration of solids in the bayer process | |
| EP1089797B1 (en) | Dextran starch and flocculant combination for improving red mud clarification | |
| AU667390B2 (en) | Trihydrate clarification aid for the bayer process | |
| AU669284B2 (en) | Use of hydroxamic acid containing polymers to improve filtration of settler overflow in Kelly filters in the Bayer process | |
| AU597113B2 (en) | Process for purifying alumina | |
| US5427750A (en) | Polymers for removing humates from bayer process liquors | |
| EP0211338A2 (en) | Process for making alumina | |
| AU691595B2 (en) | Use of anionic flocculants and hydroxamated polymers as Bayer Process red mud flocculents | |
| AU2013201696B2 (en) | Use of silicon-containing polymers to improve red mud flocculation in the Bayer process | |
| AU755418B2 (en) | Dextran, starch and flocculant combination for improving red mud clarification | |
| AU726700B2 (en) | Improved flocculation in the bayer process |