CA2470286A1 - A long term-stabilized suspension for covering iron mineral, and a process for its production - Google Patents
A long term-stabilized suspension for covering iron mineral, and a process for its production Download PDFInfo
- Publication number
- CA2470286A1 CA2470286A1 CA 2470286 CA2470286A CA2470286A1 CA 2470286 A1 CA2470286 A1 CA 2470286A1 CA 2470286 CA2470286 CA 2470286 CA 2470286 A CA2470286 A CA 2470286A CA 2470286 A1 CA2470286 A1 CA 2470286A1
- Authority
- CA
- Canada
- Prior art keywords
- alkaline
- carbonate
- long term
- stabilized suspension
- suspension
- 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.)
- Abandoned
Links
- 239000000725 suspension Substances 0.000 title claims abstract description 110
- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000008569 process Effects 0.000 title claims abstract description 27
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 20
- 229910001608 iron mineral Inorganic materials 0.000 title abstract description 16
- 239000002245 particle Substances 0.000 claims abstract description 52
- 239000008188 pellet Substances 0.000 claims abstract description 46
- 230000007774 longterm Effects 0.000 claims abstract description 41
- 239000007787 solid Substances 0.000 claims abstract description 30
- 239000000843 powder Substances 0.000 claims abstract description 22
- 239000000463 material Substances 0.000 claims abstract description 17
- 238000013019 agitation Methods 0.000 claims abstract description 11
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 8
- 239000000758 substrate Substances 0.000 claims abstract description 7
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims description 23
- 239000000347 magnesium hydroxide Substances 0.000 claims description 23
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims description 23
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 22
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 22
- 229910000000 metal hydroxide Inorganic materials 0.000 claims description 21
- 150000004692 metal hydroxides Chemical class 0.000 claims description 21
- 150000001875 compounds Chemical class 0.000 claims description 17
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 15
- 229920001448 anionic polyelectrolyte Polymers 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 239000002994 raw material Substances 0.000 claims description 11
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 claims description 8
- 239000001095 magnesium carbonate Substances 0.000 claims description 8
- 229910000021 magnesium carbonate Inorganic materials 0.000 claims description 8
- 230000001464 adherent effect Effects 0.000 claims description 7
- 238000005755 formation reaction Methods 0.000 claims description 7
- 229920001909 styrene-acrylic polymer Polymers 0.000 claims description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 6
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 5
- 239000000839 emulsion Substances 0.000 claims description 5
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 claims description 5
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 claims description 5
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 claims description 5
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 claims description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 4
- 239000004793 Polystyrene Substances 0.000 claims description 4
- PPQREHKVAOVYBT-UHFFFAOYSA-H dialuminum;tricarbonate Chemical compound [Al+3].[Al+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O PPQREHKVAOVYBT-UHFFFAOYSA-H 0.000 claims description 4
- 230000005484 gravity Effects 0.000 claims description 4
- 229920002223 polystyrene Polymers 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 3
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 3
- 239000000920 calcium hydroxide Substances 0.000 claims description 3
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 3
- 238000001914 filtration Methods 0.000 claims description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 3
- FGUUSXIOTUKUDN-IBGZPJMESA-N C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 Chemical compound C1(=CC=CC=C1)N1C2=C(NC([C@H](C1)NC=1OC(=NN=1)C1=CC=CC=C1)=O)C=CC=C2 FGUUSXIOTUKUDN-IBGZPJMESA-N 0.000 claims description 2
- 239000004115 Sodium Silicate Substances 0.000 claims description 2
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 claims description 2
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 claims description 2
- 229940118662 aluminum carbonate Drugs 0.000 claims description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 2
- 239000000378 calcium silicate Substances 0.000 claims description 2
- 229910052918 calcium silicate Inorganic materials 0.000 claims description 2
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 claims description 2
- 238000000227 grinding Methods 0.000 claims description 2
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 claims description 2
- 239000000391 magnesium silicate Substances 0.000 claims description 2
- 235000019792 magnesium silicate Nutrition 0.000 claims description 2
- 229910052919 magnesium silicate Inorganic materials 0.000 claims description 2
- 238000003801 milling Methods 0.000 claims description 2
- 239000004576 sand Substances 0.000 claims description 2
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 2
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 2
- 238000005054 agglomeration Methods 0.000 abstract description 11
- 230000002776 aggregation Effects 0.000 abstract description 11
- 238000010438 heat treatment Methods 0.000 abstract description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 28
- 235000012254 magnesium hydroxide Nutrition 0.000 description 22
- 239000000654 additive Substances 0.000 description 14
- 229910052742 iron Inorganic materials 0.000 description 13
- 230000000996 additive effect Effects 0.000 description 10
- 239000000523 sample Substances 0.000 description 10
- 230000009467 reduction Effects 0.000 description 9
- TWRXJAOTZQYOKJ-UHFFFAOYSA-L Magnesium chloride Chemical compound [Mg+2].[Cl-].[Cl-] TWRXJAOTZQYOKJ-UHFFFAOYSA-L 0.000 description 8
- 239000004568 cement Substances 0.000 description 8
- 235000014380 magnesium carbonate Nutrition 0.000 description 7
- 239000000395 magnesium oxide Substances 0.000 description 7
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 7
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 7
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 description 4
- 229910001629 magnesium chloride Inorganic materials 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 235000011116 calcium hydroxide Nutrition 0.000 description 2
- 229920006317 cationic polymer Polymers 0.000 description 2
- -1 chlorine ions Chemical class 0.000 description 2
- 239000013068 control sample Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000010459 dolomite Substances 0.000 description 2
- 229910000514 dolomite Inorganic materials 0.000 description 2
- 230000000887 hydrating effect Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910052943 magnesium sulfate Inorganic materials 0.000 description 2
- 235000019341 magnesium sulphate Nutrition 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 230000008719 thickening Effects 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
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-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
- 239000004952 Polyamide Substances 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229940024548 aluminum oxide Drugs 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 229910001570 bauxite Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 235000010216 calcium carbonate Nutrition 0.000 description 1
- 235000012241 calcium silicate Nutrition 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- CJYQQUPRURWLOW-YDLUHMIOSA-M dmsc Chemical compound [Na+].OP(=O)=O.OP(=O)=O.OP(=O)=O.[O-]P(=O)=O.O=C1C2=C(O)C=CC=C2[C@H](C)[C@@H]2C1=C(O)[C@]1(O)C(=O)C(C(N)=O)=C(O)[C@@H](N(C)C)[C@@H]1[C@H]2O CJYQQUPRURWLOW-YDLUHMIOSA-M 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000003995 emulsifying agent Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229920002521 macromolecule Polymers 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000447 polyanionic polymer Polymers 0.000 description 1
- 229920000867 polyelectrolyte Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000002893 slag Substances 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
- 239000010959 steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/2406—Binding; Briquetting ; Granulating pelletizing
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
- C01F5/16—Magnesium hydroxide by treating magnesia, e.g. calcined dolomite, with water or solutions of salts not containing magnesium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
- C01F5/20—Magnesium hydroxide by precipitation from solutions of magnesium salts with ammonia
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
- C01F5/22—Magnesium hydroxide from magnesium compounds with alkali hydroxides or alkaline- earth oxides or hydroxides
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/008—Use of special additives or fluxing agents
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B5/00—Making pig-iron in the blast furnace
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/2413—Binding; Briquetting ; Granulating enduration of pellets
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/10—Solid density
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/242—Binding; Briquetting ; Granulating with binders
- C22B1/243—Binding; Briquetting ; Granulating with binders inorganic
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Mechanical Engineering (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Powder Metallurgy (AREA)
- Paints Or Removers (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Adhesives Or Adhesive Processes (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
A long term stabilized suspension, and process for its production which can be used for covering briquettes, particles, pellets or powders of iron mineral and other several materials, in order to avoid its agglomeration when stored or submitted to a heat treatment; and which can be stored for at least three months without substantial agitation and without experimenting substantial settlement and the formation of a solid hard substrate.
Description
A LONG TERM-STABILIZED SUSPENSION FOR COVERING IRON MINERAL, AND A PROCESS FOR ITS PRODUCTION
BACKGROUND OF THE INVENTION
A. FIELD OF THE INVENTION
This invention relates to a stabilized suspension and more particularly to a long term-stabilized suspension, having a stability of at least three months without substantially settling and without forming a hard solid substrate, for covering briquettes, particles, pellets or powder of iron mineral and also of several materials in order to avoid the adhesion between each other and thus its agglomeration when stored or submitted to a heat treatment and a process for its production and application.
B. DESCRIPTION OF RELATED ART
In the treatment of briquettes, particles or pellets made of materials such as dolomite, magnesite, iron ore, etc., in which is necessary to sinter a plurality of briquettes, particles or pellets inside furnaces at high temperatures, there is a tendency of said materials to adhere to each other producing an agglomeration or clustering of briquettes.
Some of these treatments comprise the direct reduction iron of mineral iron pellets inside a furnace at high temperatures, and also the production of steel in a Blast Furnace. When the sintering is complete, usually, some or all of the pellets are agglomerated in a solid mass, forming a cluster and making necessary to submit the solid mass to a mechanic shock in order to separate each pellet from the agglomerate.
In order to avoid the agglomeration of pellets during sintering, there were tested several compounds which must be applied over the pellet's surface before the sintering process. Among these compounds, there were tested slurries of magnesium hydroxide, calcium hydroxide, bauxite and even cement, but none of these compounds produced the expected results, and had some disadvantages when used for the above referred purpose. Some of the disadvantages related to the previously mentioned compounds comprise the necessity of continuously stir the slurries in order to maintain a constant concentration, and that once the compound was applied over the pellets, the compounds proved to have a very bad adherence to the briquettes, particles or pellets, since the cover, once it dries, tends to separate from the particles only by the movement produced by normal manipulation of the particles.
When it is necessary to transport the suspension to places far away from the Production Plant, as well as for further processing, it is necessary to store the suspension for a long time in a storage container. Under such circumstances, the solid particles of the suspension normally tend to settle down producing a hard solid substrate as a hard cake in the bottom of the storage container, which is often very difficult to remove. Under such circumstances, the remaining suspension results useless because it doesn't have the required concentration and the particles in suspension do not have the required particle size and therefore it has to be poured from the storage container and discarded in order to remove the hard solid cake from the bottom of the container, increasing costs and high raw material loses.
Therefore, it would be highly desirable to have and produce a suspension which may be used for covering briquettes, particles, pellets or powder iron and several kinds of materials in order to avoid the agglomeration of a plurality of particles when stored or submitted to a heat treatment on Direct Reduction Furnace or Blast Furnace for example, having good adherence properties and which may be stored for long terms without substantially settling and cake DMSLcgnl\053G38\00001\18072G3v1 formation.
U.S. patent No. 4,743,396 disclose a magnesium hydroxide slurry, for very specific purposes, having a concentration of 50% by weight or higher of Mg(OH)2 and 0.1 to 5% of a sulfomethylated polyacrylamide which allow the slurry to be pumped through pipelines.
Furthermore, U.S. patents No. 4,164,521 (involving the use of a polyanionic polymer containing at least 50% mole of repetitive units derived from an acrylic acid and a polycathionic polymer); 4,412,844 (involving the use of 1.0 to 8.0% of a water dispersible, oil-soluble emulsifying agent); 4,155,741 (including an encapsulated material); and 3,957,674 (including at least 0.5%
of sodium naphtalen-sulfonate), all of them disclose suspensions which, when there were stored for long periods of time, showed some settlement but when they are agitated, they recover their concentration and physical properties, but all of them do not mention a long term stability of about three months.
Because of its nature, a stabilized suspension can be more easily pumped than one which is not stabilized because the non-stabilized suspension tends to form thickened particles and solid substrates complicating or even impeding their pumping.
PCT published patent application No. PCT/AU95/00446 discloses an example of a magnesium hydroxide suspension having both characteristics of pumping and stability for about seven days without substantial agitation.
However, up to now, there is no suspension in the market having a long term stability of about three months and which may be used for covering briquettes, particles, pellets or iron powder.
Regarding processes for producing suspensions, U.S. patent No.
5,487,979 disclose a process for the production of magnesium hydroxide DMSLegal\053638\00001 \1807263v 1 suspension, by pressure hydrating burnt natural magnesite in presence of chlorine ions and a cationic polymer (polyamide).
U.S. Patents Nos. 5,143,965; 4,548,733; 4,430,248; 4,230,610; 4,166,040;
and 4,166,041 disclose representative processes for producing magnesium hydroxide suspensions, by using ultrasonic mixing steps and some cationic polymers such as the ammonium metacriloxiethyl-trimethyl-methasulfonate and the polyacrylic acid, among others, showing more or less stability, but none disclosing a stability near a range of about three months.
SUMMARY OF THE INVENTION
It is therefore highly desirable to provide a long term stabilized suspension and a new process for producing a long term stabilized suspension, which stabilized suspension may be used for covering briquettes, particles, pellets or powders of iron mineral and other several materials in order to avoid the agglomeration of a plurality of briquettes, particles, pellets or powders when stored or submitted to heat treatments on Direct Reduction Furnaces or Blast Furnaces, and that additionally, may be stored for long terms without substantially settling.
In accordance with the present invention, it is disclosed a suspension having a content of from 50 to 70% in weight of an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate, a solid content between about 52%
to 72%, a water content of 28% to 48%, a viscosity of about 1000 centipoises (cp), a average particle size of about 2 microns, a pH value greater than 10.5, an equivalent magnesium oxide content of 34% to 48%, a specific gravity of 1.40 to 1.60, and including one or more anionic polyelectrolytes, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis, and an adherent compound applied to the suspension, at a concentration of at least 30% in an amount of 0.5 to 5%, in dry basis, showing a stability of at least three months DMSLcgal\053638\OOOOI U 807263v 1 without substantial agitation, and which may be used for covering briquettes, particles, pellets or powders of iron mineral and several kinds of materials in order to avoid its agglomeration when treated at high temperatures .
Thanks to the average particle size (of about 2 microns) in combination with the use of the anionic polyelectrolytes, the suspension may be stable over a number, for example, three, months. In fact this product may require only somewhat (not vigorous) agitation once a day, in order to keep it fluid without experiencing particle thickening or substantial settlement.
Regarding the production of stabilized suspensions, these can be produced by adding a soluble alkaline material to an aqueous salt of, for example, magnesium at atmospheric pressure and at a temperature from near ambient temperature to about 100°C.
A process for the production of the stabilized suspension, in accordance with the present invention, may comprise producing a paste comprising an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate, washing and repulping the paste in order to reduce the soluble salts; reducing the particle size until approximately 2 microns average; adding additives for improving the fluidity and stability of the suspension, and adding an adherent compound in order to obtain a long term stability to the suspension which has a stability of at least three months without substantial agitation, which does not settle down forming a hard solid cemented cake, and which can be used for covering briquettes, particles, pellets or powders of iron mineral and also several kinds of materials, in order to avoid its agglomeration when stored or submitted to high temperatures on Direct Reduction Furnaces or Blast Furnaces; said suspension may be applied to the surface of the briquettes, particles, pellets or powders by averages of a plurality of spraying nozzles, which are passed under said spraying nozzles by averages of a conveyor belt.
DMSLegal\053638\00001 U 807263 v 1 The suspension of the present invention has a high coverage area, of 5m2/g minimum, and it can be applied on the surface of the briquettes, particles, pellets or powders, as a diluted suspension having a concentration of from 4 to 50% in weight. Furthermore, the suspension of the present invention adheres strongly to the briquettes, particles, pellets or powders so it does not separate from the surface of the briquettes, particles, pellets or powders during transportation, manipulation and different treatment phases.
By covering the briquettes, particles, pellets or powders with the suspension of the present invention there are obtained the following benefits:
~ Lesser maintenance costs of conveyor belts, rollers, sieving devices, etc.
~ Easier product manipulation procedures, thanks to the liquid nature of the suspension of the present invention.
~ Few emanations of hazardous and polluting elements to the environment.
~ When the suspension of the present invention is used for covering iron ore pellets to be treated at high temperatures in order to reduce the iron ore, there are obtained high quality reduced iron pellets.
~ High productivity in Furnaces working at temperatures greater than 1,000 °C.
~ Improved slag fluidity, and easier removal of impurities inside pipes, containers, etc.
Thus in accordance with a broad aspect of the present invention, there is DMSLega1\053638\00001 \I 807263v 1 provided a long term stabilized suspension, which can be used for covering briquettes, particles, pellets or powder of several kinds of materials for avoiding adhesion between each other and thus the formation of agglomerates when treated at high temperatures having:
a solid content of about 52% to 72%;
a water content of about 28% to 48%;
a viscosity of about 500 to 1,500 cp.;
an average particle size of about 1 to 3 microns;
an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of about 50% to 70% in weight;
a pH value of over 10.5;
an equivalent alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of 34% to 48%;
a specific gravity of 1.4 to 1.6;
at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis and and an adherent compound that improves the adhesion of the suspension to the pellets or briquettes during the process, at a concentration of at least 30%
in an amount of 0.5 to 5% in dry basis;
wherein the long-term stabilized suspension can be stored for at least three months without substantial agitation, and without experiencing substantial settlement and solid hard substrate formations.
DMSLegal\053638\00001 \1807263v 1 In some embodiments, the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate may include magnesium hydroxide, magnesium carbonate, magnesium silicate, calcium hydroxide, calcium carbonate, calcium silicate, aluminum hydroxide, aluminum carbonate, aluminum silicate, sodium hydroxide, sodium carbonate and/or sodium silicate.
In some embodiments, the anionic polyelectrolyte may be selected from the group consisting of sodium polyacrylate and ammonium polystyrene/maleate.
In one embodiment, the adherent compound may be selected from styrene acrylic emulsions.
In one embodiment, the long term stabilized suspension may have a coverage area of 5 m2/g minimum.
The long term stabilized suspension may be applied on the surface of the briquettes, particles, pellets or powders and may be in the form of a diluted suspension having a concentration of from 4 to 50% in weight.
In accordance with another aspect of the present invention, there is provided a process for the production of a long term stabilized suspension using as raw material an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate and the process may include:
a) washing the raw material solids;
b) filtering and repulping the raw material solids in order to obtain agglomerated solid particles having less than 0.6% of chloride values;
c) adding at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis.
d) dispersing the agglomerated solid particles in a dispersing equipment;
DMSC.egal\053638\00001 \1807263 v 1 e) grinding the dispersed product, to reduce the particle size so that at least the 50% of the ground product have a particle size of about 2 microns;
f) adding an compound type styrene acrylic emulsion, at a concentration of at least 30% in an amount of 0.5 to 5% in dry basis; and g) dispersing the product of step f) in a dispersing equipment.
In one embodiment, the step d) may be carried out in a minimum 5 minutes.
In one embodiment, the step e) may be carried out in a sand mill using high density balls, as milling media.
In an embodiment of the invention, the anionic polyelectrolyte may include sodium polyacrylate or ammonium polystyrene/maleate.
It is therefore a main object of the present invention, to provide a long-term stabilized suspension, for covering briquettes, particles, pellets or powders of iron or other several materials, for avoiding its agglomeration when treated at high temperatures on Direct Reduction Furnaces or Blast Furnaces for example, having good adherence properties and a high coverage area.
It is another object of the present invention, to provide a long-term stabilized suspension of the above disclosed nature, having a stability of at least three months without substantial agitation, and having a very low tendency to settle down, forming a hard cemented cake.
It is still main object of the present invention, to provide a process for the production of a long-term stabilized suspension, for covering briquettes, particles, pellets or powders of iron mineral and several kinds of materials, for avoiding its agglomeration when treated at high temperatures, having good adherence properties and a high coverage area.
DMSiegal\053G38\00001\18072G3v1 C
These and other objects and advantages of the present invention will be apparent to those persons having ordinary skill in the art, from the following description of the invention, referring to specific examples of practice.
DETAILED DESCRIPTION OF THE INVENTION.
The invention will be described in the following by making reference to a preferred embodiment and some specific examples of the process and materials used to produce the a long-term stabilized suspension which can be used for covering briquettes, particles, pellets or powder of iron mineral and other several materials, in order to avoid its agglomeration when treated at high temperatures, and having a stability of at least three months without substantial agitation, and which has a very low tendency to settle down forming a hard solid cemented cake.
In a preferred embodiment, a raw material of magnesium hydroxide Mg(OH)2 may be used, which may be produced by the following processes:
~ Production of magnesium hydroxide by reacting calcined dolomite or limestone with sea water or magnesium chloride brines ~ Production of magnesium hydroxide by thermal decomposition of magnesium chloride brines.
~ Production of magnesium hydroxide by burning natural magnesite (magnesium carbonate) in order to obtain magnesium oxide which afterwards is hydrated with water in order to obtain magnesium hydroxide.
~ Production of magnesium hydroxide by hydrating Magnesium Oxide ~ Production of magnesium hydroxide by reacting sodium hydroxide with magnesium sulfate or Epsom salt.
DMSLegal\053638\00001 \1807263v1 1 O
~ Production of magnesium hydroxide from sodium hydroxide and magnesium chloride brines.
~ From ammonia or ammonium hydroxide with magnesium chloride brines.
In one embodiment, the process for producing a long-term stabilized suspension may comprise:
washing the magnesium hydroxide;
filtering and repulping the magnesium hydroxide solids in order to obtain chloride values of less than 0.6%;
dispersing the agglomerated solid particles in a dispersing equipment for a minimum 5 minutes;
adding one or more anionic polyelectrolytes at a concentration of at least 25% in an amount of about 0.5 to 2.5% in dry basis;
conditioning and micronizing the magnesium hydroxide solids in order to reduce the particle size until approximately 2 microns;
adding a styrene acrylic emulsion, at a concentration of at least 30% in an amount of 0.5 to 5% in dry basis;
dispersing the product obtained by the above step; and storing the obtained suspension in a storing tank wherein it can be stored for at least three months without substantially agitation without experimenting tendency to settle down forming a hard solid cake in the bottom of the storage tank, nor particle thickening of the solid particles of the suspension and which can be used to cover briquettes, particles, pellets or powders of iron mineral and different materials.
DMSLegal\053638\00001 \1807263v 1 1 1 By the above referred process it is obtained a long-term stabilized suspension having a pH of over 10.5; solid content of about 52% to 72%; a water content of about 28% to 48%; a viscosity of about 500 to 1,500 cp; an average particle size of about 1 to 3 microns; an Mg(OH)2 content of about 50% to 70%;
a pH value of over 10.5; an equivalent magnesium oxide content of 34% to 48%; a specific gravity of 1.4 to 1.6; at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis;
and an adherent compound that improves the adhesion of the suspension to the pellets or briquettes during the process, at a concentration of at least 30%
in an amount of 0.5 to 5% in dry basis; which can be stored for at least three months without substantial agitation, and without experimenting substantial settlement and the formation of a solid hard substrate formation.
The anionic polyelectrolytes are macromolecules originated from monomeric units with ionizable groups in comparison with a simple electrolyte such as the sodium chloride in which the Na+ cation and the CI- anion are relatively small and similar in size. A polyelectrolyte is characterized by having a macro ion which is the vertebral column (a large ion and similar number of charged groups connected by bonds) and an equivalent number of independent and opposite small charges. Because of their high molecular weight, these are also known as dispersant resins.
Examples of anionic polyelectrolytes are: sodium polyacrylate, ammonium poly(styrene/maleate) among others.
The suspension of the present invention may have a high coverage area of, for example, 5 m2/g minimum, and it can be applied on the surface of the briquettes, particles, pellets or powders, as a diluted suspension having a concentration of from 4 to 50%.
Although it was described that the raw material may comprise magnesium DMSL.egal\053638\00001\18072G3v1 12 hydroxide, it may comprise magnesium/ calcium/ aluminum/ sodium hydroxide/
carbonate/ silicate.
The following are examples of the specific process for obtaining the long-term stabilized suspension in accordance with the present invention:
A sample of the long-term stabilized suspension was prepared and was divided in three portions.
Each portion was diluted with good quality water in order to obtain concentrations of 1, 2 and 5% in weight.
Adhesion tests were carried out for each sample by covering iron mineral pellets with each portion. An additional adhesion test was carried out using a sample of cement at a concentration of 15% in weight for comparison purposes, as well as another adhesion test using a control sample having no adhesion additives.
The 5 samples were placed inside a laboratory reactor in order to carry out the iron mineral reduction (change of iron oxide to metallic iron) and the following results were obtained:
DMSLegal\053G38\00001\18072G3v1 13 Sample % of clustering Control, without additives 87 Cement suspension at 15 % 30 Stabilized suspension at 5 % 4 Stabilized suspension at 2 % 10 Stabilized suspension at 1 % 19 The best results were obtained with the suspension at 5%, by which a lesser quantity of agglomerated pellets were produced at the reactor exit, and even at a concentration of 1 % there were obtained better results compared to the results obtained with the cement suspension at 15%.
A sample of the long-term stabilized suspension was prepared and divided in six portions.
Two portions were diluted with water in order to obtain a concentration of 2% in weight, another two portions were diluted at a 3% in weight and the last two portions were diluted at a 5% in weight.
Each portion was used to cover iron mineral pellets. Three samples were maintained with concentrations of 2%, 3% and 5%, and three samples were air blew (i.e. dried) in order to eliminate water excess and to determine if the DMSLegal\053G38\00001\18072G3v1 14 adherence to the pellets decreases.
The 6 samples were placed inside a laboratory reactor in order to carry out the iron mineral reduction and the following results were obtained:
Sample % of clustering Stabilized suspension at 2 % 15 Stabilized suspension at 2 % air blew 19 Stabilized suspension at 3 % 11 Stabilized suspension at 3 % air blew 14 Stabilized suspension at 5 % 6 Stabilized suspension at 5 % air blew 11 From the above referred results, It can be concluded that air blowing the samples before placing them inside the reactor, produce a slight decrease of the stabilized suspension performance, but there was always obtained low percentages of agglomerated pellets.
Four samples of the stabilized suspension were prepared, adding a styrene acrylic compound to each sample, in amounts of from between about 2%
to 5% in weight.
The four samples were diluted with water until obtain a final concentration of 5% in weight which were used to cover iron mineral pellets. Subsequently the pellets covered with the stabilized suspension samples were placed inside a DMSLegal\053638W0001\1807263v1 I S
reactor in order to carry out an iron reduction and the following results were obtained. A control sample comprising a cement suspension at a concentration of 15% in weight having no additives, was also evaluated. The following results were obtained:
Sample % of clustering Stabilized suspension with a 2% of additive 14 Stabilized suspension with a 3% of additive 9 Stabilized suspension with a 4% of additive 8 Stabilized suspension with a 5% of additive 8 Cement suspension at 15% without additive 28 From the above experiment it can be concluded that the lesser percentage of remnant agglomerates were obtained with additive amounts of 4% and 5% in weight.
Three samples of the stabilized suspension were prepared, using as a raw material natural magnesite (magnesium carbonate) which was burned at a temperature of 900°C in order to obtain magnesium oxide.
After obtaining the magnesium oxide, water was added to the magnesium oxide in order to obtain magnesium hydroxide and to adjust its concentration at 55% in weight.
DMSLegal\053638\00001\1807263v1 16 The obtained suspension was divided in three portions, adding 1 %, 3%
and 5% in weight of a styrene acrylic compound to each portion respectively.
Finally there was added water in order to obtain a magnesium hydroxide concentration of 5% in weight.
Each sample was used to cover different iron pellets which were placed inside a laboratory reactor in order to carry out an iron reduction at a temperature of 950°C.
Other iron pellets were covered with a cement suspension at a concentration of 15% in weight and placed inside the same reactor in order to use them as control samples. The following results were obtained:
Sample % of clustering Stabilized suspension with 1 % of additive 15 Stabilized suspension with 3% of additive 9 Stabilized suspension with 5% of additive 8 Cement suspension at 15% 26 The best results were obtained with the stabilized suspensions having additive amounts of 3% and 5%. Also there was demonstrated that the stabilized suspension of the present invention may be produced using other different raw materials.
Finally it must be understood that the long term-stabilized suspension, for covering briquettes, particles, pellets or powder iron and the process for its production and application of the present invention, is not limited exclusively to the above described and illustrated embodiments and that the persons having DMSLegal\053638\00001 \18072G3v 1 ordinary skill in the art can, with the teaching provided by this invention, make modifications to the long term-stabilized suspension for covering iron mineral and the process for its production and application of the present invention, which will clearly be within the true inventive concept and scope of the invention which is claimed in the following claims.
DMSLegal\053638\00001 \1807263v 1 18
BACKGROUND OF THE INVENTION
A. FIELD OF THE INVENTION
This invention relates to a stabilized suspension and more particularly to a long term-stabilized suspension, having a stability of at least three months without substantially settling and without forming a hard solid substrate, for covering briquettes, particles, pellets or powder of iron mineral and also of several materials in order to avoid the adhesion between each other and thus its agglomeration when stored or submitted to a heat treatment and a process for its production and application.
B. DESCRIPTION OF RELATED ART
In the treatment of briquettes, particles or pellets made of materials such as dolomite, magnesite, iron ore, etc., in which is necessary to sinter a plurality of briquettes, particles or pellets inside furnaces at high temperatures, there is a tendency of said materials to adhere to each other producing an agglomeration or clustering of briquettes.
Some of these treatments comprise the direct reduction iron of mineral iron pellets inside a furnace at high temperatures, and also the production of steel in a Blast Furnace. When the sintering is complete, usually, some or all of the pellets are agglomerated in a solid mass, forming a cluster and making necessary to submit the solid mass to a mechanic shock in order to separate each pellet from the agglomerate.
In order to avoid the agglomeration of pellets during sintering, there were tested several compounds which must be applied over the pellet's surface before the sintering process. Among these compounds, there were tested slurries of magnesium hydroxide, calcium hydroxide, bauxite and even cement, but none of these compounds produced the expected results, and had some disadvantages when used for the above referred purpose. Some of the disadvantages related to the previously mentioned compounds comprise the necessity of continuously stir the slurries in order to maintain a constant concentration, and that once the compound was applied over the pellets, the compounds proved to have a very bad adherence to the briquettes, particles or pellets, since the cover, once it dries, tends to separate from the particles only by the movement produced by normal manipulation of the particles.
When it is necessary to transport the suspension to places far away from the Production Plant, as well as for further processing, it is necessary to store the suspension for a long time in a storage container. Under such circumstances, the solid particles of the suspension normally tend to settle down producing a hard solid substrate as a hard cake in the bottom of the storage container, which is often very difficult to remove. Under such circumstances, the remaining suspension results useless because it doesn't have the required concentration and the particles in suspension do not have the required particle size and therefore it has to be poured from the storage container and discarded in order to remove the hard solid cake from the bottom of the container, increasing costs and high raw material loses.
Therefore, it would be highly desirable to have and produce a suspension which may be used for covering briquettes, particles, pellets or powder iron and several kinds of materials in order to avoid the agglomeration of a plurality of particles when stored or submitted to a heat treatment on Direct Reduction Furnace or Blast Furnace for example, having good adherence properties and which may be stored for long terms without substantially settling and cake DMSLcgnl\053G38\00001\18072G3v1 formation.
U.S. patent No. 4,743,396 disclose a magnesium hydroxide slurry, for very specific purposes, having a concentration of 50% by weight or higher of Mg(OH)2 and 0.1 to 5% of a sulfomethylated polyacrylamide which allow the slurry to be pumped through pipelines.
Furthermore, U.S. patents No. 4,164,521 (involving the use of a polyanionic polymer containing at least 50% mole of repetitive units derived from an acrylic acid and a polycathionic polymer); 4,412,844 (involving the use of 1.0 to 8.0% of a water dispersible, oil-soluble emulsifying agent); 4,155,741 (including an encapsulated material); and 3,957,674 (including at least 0.5%
of sodium naphtalen-sulfonate), all of them disclose suspensions which, when there were stored for long periods of time, showed some settlement but when they are agitated, they recover their concentration and physical properties, but all of them do not mention a long term stability of about three months.
Because of its nature, a stabilized suspension can be more easily pumped than one which is not stabilized because the non-stabilized suspension tends to form thickened particles and solid substrates complicating or even impeding their pumping.
PCT published patent application No. PCT/AU95/00446 discloses an example of a magnesium hydroxide suspension having both characteristics of pumping and stability for about seven days without substantial agitation.
However, up to now, there is no suspension in the market having a long term stability of about three months and which may be used for covering briquettes, particles, pellets or iron powder.
Regarding processes for producing suspensions, U.S. patent No.
5,487,979 disclose a process for the production of magnesium hydroxide DMSLegal\053638\00001 \1807263v 1 suspension, by pressure hydrating burnt natural magnesite in presence of chlorine ions and a cationic polymer (polyamide).
U.S. Patents Nos. 5,143,965; 4,548,733; 4,430,248; 4,230,610; 4,166,040;
and 4,166,041 disclose representative processes for producing magnesium hydroxide suspensions, by using ultrasonic mixing steps and some cationic polymers such as the ammonium metacriloxiethyl-trimethyl-methasulfonate and the polyacrylic acid, among others, showing more or less stability, but none disclosing a stability near a range of about three months.
SUMMARY OF THE INVENTION
It is therefore highly desirable to provide a long term stabilized suspension and a new process for producing a long term stabilized suspension, which stabilized suspension may be used for covering briquettes, particles, pellets or powders of iron mineral and other several materials in order to avoid the agglomeration of a plurality of briquettes, particles, pellets or powders when stored or submitted to heat treatments on Direct Reduction Furnaces or Blast Furnaces, and that additionally, may be stored for long terms without substantially settling.
In accordance with the present invention, it is disclosed a suspension having a content of from 50 to 70% in weight of an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate, a solid content between about 52%
to 72%, a water content of 28% to 48%, a viscosity of about 1000 centipoises (cp), a average particle size of about 2 microns, a pH value greater than 10.5, an equivalent magnesium oxide content of 34% to 48%, a specific gravity of 1.40 to 1.60, and including one or more anionic polyelectrolytes, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis, and an adherent compound applied to the suspension, at a concentration of at least 30% in an amount of 0.5 to 5%, in dry basis, showing a stability of at least three months DMSLcgal\053638\OOOOI U 807263v 1 without substantial agitation, and which may be used for covering briquettes, particles, pellets or powders of iron mineral and several kinds of materials in order to avoid its agglomeration when treated at high temperatures .
Thanks to the average particle size (of about 2 microns) in combination with the use of the anionic polyelectrolytes, the suspension may be stable over a number, for example, three, months. In fact this product may require only somewhat (not vigorous) agitation once a day, in order to keep it fluid without experiencing particle thickening or substantial settlement.
Regarding the production of stabilized suspensions, these can be produced by adding a soluble alkaline material to an aqueous salt of, for example, magnesium at atmospheric pressure and at a temperature from near ambient temperature to about 100°C.
A process for the production of the stabilized suspension, in accordance with the present invention, may comprise producing a paste comprising an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate, washing and repulping the paste in order to reduce the soluble salts; reducing the particle size until approximately 2 microns average; adding additives for improving the fluidity and stability of the suspension, and adding an adherent compound in order to obtain a long term stability to the suspension which has a stability of at least three months without substantial agitation, which does not settle down forming a hard solid cemented cake, and which can be used for covering briquettes, particles, pellets or powders of iron mineral and also several kinds of materials, in order to avoid its agglomeration when stored or submitted to high temperatures on Direct Reduction Furnaces or Blast Furnaces; said suspension may be applied to the surface of the briquettes, particles, pellets or powders by averages of a plurality of spraying nozzles, which are passed under said spraying nozzles by averages of a conveyor belt.
DMSLegal\053638\00001 U 807263 v 1 The suspension of the present invention has a high coverage area, of 5m2/g minimum, and it can be applied on the surface of the briquettes, particles, pellets or powders, as a diluted suspension having a concentration of from 4 to 50% in weight. Furthermore, the suspension of the present invention adheres strongly to the briquettes, particles, pellets or powders so it does not separate from the surface of the briquettes, particles, pellets or powders during transportation, manipulation and different treatment phases.
By covering the briquettes, particles, pellets or powders with the suspension of the present invention there are obtained the following benefits:
~ Lesser maintenance costs of conveyor belts, rollers, sieving devices, etc.
~ Easier product manipulation procedures, thanks to the liquid nature of the suspension of the present invention.
~ Few emanations of hazardous and polluting elements to the environment.
~ When the suspension of the present invention is used for covering iron ore pellets to be treated at high temperatures in order to reduce the iron ore, there are obtained high quality reduced iron pellets.
~ High productivity in Furnaces working at temperatures greater than 1,000 °C.
~ Improved slag fluidity, and easier removal of impurities inside pipes, containers, etc.
Thus in accordance with a broad aspect of the present invention, there is DMSLega1\053638\00001 \I 807263v 1 provided a long term stabilized suspension, which can be used for covering briquettes, particles, pellets or powder of several kinds of materials for avoiding adhesion between each other and thus the formation of agglomerates when treated at high temperatures having:
a solid content of about 52% to 72%;
a water content of about 28% to 48%;
a viscosity of about 500 to 1,500 cp.;
an average particle size of about 1 to 3 microns;
an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of about 50% to 70% in weight;
a pH value of over 10.5;
an equivalent alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of 34% to 48%;
a specific gravity of 1.4 to 1.6;
at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis and and an adherent compound that improves the adhesion of the suspension to the pellets or briquettes during the process, at a concentration of at least 30%
in an amount of 0.5 to 5% in dry basis;
wherein the long-term stabilized suspension can be stored for at least three months without substantial agitation, and without experiencing substantial settlement and solid hard substrate formations.
DMSLegal\053638\00001 \1807263v 1 In some embodiments, the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate may include magnesium hydroxide, magnesium carbonate, magnesium silicate, calcium hydroxide, calcium carbonate, calcium silicate, aluminum hydroxide, aluminum carbonate, aluminum silicate, sodium hydroxide, sodium carbonate and/or sodium silicate.
In some embodiments, the anionic polyelectrolyte may be selected from the group consisting of sodium polyacrylate and ammonium polystyrene/maleate.
In one embodiment, the adherent compound may be selected from styrene acrylic emulsions.
In one embodiment, the long term stabilized suspension may have a coverage area of 5 m2/g minimum.
The long term stabilized suspension may be applied on the surface of the briquettes, particles, pellets or powders and may be in the form of a diluted suspension having a concentration of from 4 to 50% in weight.
In accordance with another aspect of the present invention, there is provided a process for the production of a long term stabilized suspension using as raw material an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate and the process may include:
a) washing the raw material solids;
b) filtering and repulping the raw material solids in order to obtain agglomerated solid particles having less than 0.6% of chloride values;
c) adding at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis.
d) dispersing the agglomerated solid particles in a dispersing equipment;
DMSC.egal\053638\00001 \1807263 v 1 e) grinding the dispersed product, to reduce the particle size so that at least the 50% of the ground product have a particle size of about 2 microns;
f) adding an compound type styrene acrylic emulsion, at a concentration of at least 30% in an amount of 0.5 to 5% in dry basis; and g) dispersing the product of step f) in a dispersing equipment.
In one embodiment, the step d) may be carried out in a minimum 5 minutes.
In one embodiment, the step e) may be carried out in a sand mill using high density balls, as milling media.
In an embodiment of the invention, the anionic polyelectrolyte may include sodium polyacrylate or ammonium polystyrene/maleate.
It is therefore a main object of the present invention, to provide a long-term stabilized suspension, for covering briquettes, particles, pellets or powders of iron or other several materials, for avoiding its agglomeration when treated at high temperatures on Direct Reduction Furnaces or Blast Furnaces for example, having good adherence properties and a high coverage area.
It is another object of the present invention, to provide a long-term stabilized suspension of the above disclosed nature, having a stability of at least three months without substantial agitation, and having a very low tendency to settle down, forming a hard cemented cake.
It is still main object of the present invention, to provide a process for the production of a long-term stabilized suspension, for covering briquettes, particles, pellets or powders of iron mineral and several kinds of materials, for avoiding its agglomeration when treated at high temperatures, having good adherence properties and a high coverage area.
DMSiegal\053G38\00001\18072G3v1 C
These and other objects and advantages of the present invention will be apparent to those persons having ordinary skill in the art, from the following description of the invention, referring to specific examples of practice.
DETAILED DESCRIPTION OF THE INVENTION.
The invention will be described in the following by making reference to a preferred embodiment and some specific examples of the process and materials used to produce the a long-term stabilized suspension which can be used for covering briquettes, particles, pellets or powder of iron mineral and other several materials, in order to avoid its agglomeration when treated at high temperatures, and having a stability of at least three months without substantial agitation, and which has a very low tendency to settle down forming a hard solid cemented cake.
In a preferred embodiment, a raw material of magnesium hydroxide Mg(OH)2 may be used, which may be produced by the following processes:
~ Production of magnesium hydroxide by reacting calcined dolomite or limestone with sea water or magnesium chloride brines ~ Production of magnesium hydroxide by thermal decomposition of magnesium chloride brines.
~ Production of magnesium hydroxide by burning natural magnesite (magnesium carbonate) in order to obtain magnesium oxide which afterwards is hydrated with water in order to obtain magnesium hydroxide.
~ Production of magnesium hydroxide by hydrating Magnesium Oxide ~ Production of magnesium hydroxide by reacting sodium hydroxide with magnesium sulfate or Epsom salt.
DMSLegal\053638\00001 \1807263v1 1 O
~ Production of magnesium hydroxide from sodium hydroxide and magnesium chloride brines.
~ From ammonia or ammonium hydroxide with magnesium chloride brines.
In one embodiment, the process for producing a long-term stabilized suspension may comprise:
washing the magnesium hydroxide;
filtering and repulping the magnesium hydroxide solids in order to obtain chloride values of less than 0.6%;
dispersing the agglomerated solid particles in a dispersing equipment for a minimum 5 minutes;
adding one or more anionic polyelectrolytes at a concentration of at least 25% in an amount of about 0.5 to 2.5% in dry basis;
conditioning and micronizing the magnesium hydroxide solids in order to reduce the particle size until approximately 2 microns;
adding a styrene acrylic emulsion, at a concentration of at least 30% in an amount of 0.5 to 5% in dry basis;
dispersing the product obtained by the above step; and storing the obtained suspension in a storing tank wherein it can be stored for at least three months without substantially agitation without experimenting tendency to settle down forming a hard solid cake in the bottom of the storage tank, nor particle thickening of the solid particles of the suspension and which can be used to cover briquettes, particles, pellets or powders of iron mineral and different materials.
DMSLegal\053638\00001 \1807263v 1 1 1 By the above referred process it is obtained a long-term stabilized suspension having a pH of over 10.5; solid content of about 52% to 72%; a water content of about 28% to 48%; a viscosity of about 500 to 1,500 cp; an average particle size of about 1 to 3 microns; an Mg(OH)2 content of about 50% to 70%;
a pH value of over 10.5; an equivalent magnesium oxide content of 34% to 48%; a specific gravity of 1.4 to 1.6; at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis;
and an adherent compound that improves the adhesion of the suspension to the pellets or briquettes during the process, at a concentration of at least 30%
in an amount of 0.5 to 5% in dry basis; which can be stored for at least three months without substantial agitation, and without experimenting substantial settlement and the formation of a solid hard substrate formation.
The anionic polyelectrolytes are macromolecules originated from monomeric units with ionizable groups in comparison with a simple electrolyte such as the sodium chloride in which the Na+ cation and the CI- anion are relatively small and similar in size. A polyelectrolyte is characterized by having a macro ion which is the vertebral column (a large ion and similar number of charged groups connected by bonds) and an equivalent number of independent and opposite small charges. Because of their high molecular weight, these are also known as dispersant resins.
Examples of anionic polyelectrolytes are: sodium polyacrylate, ammonium poly(styrene/maleate) among others.
The suspension of the present invention may have a high coverage area of, for example, 5 m2/g minimum, and it can be applied on the surface of the briquettes, particles, pellets or powders, as a diluted suspension having a concentration of from 4 to 50%.
Although it was described that the raw material may comprise magnesium DMSL.egal\053638\00001\18072G3v1 12 hydroxide, it may comprise magnesium/ calcium/ aluminum/ sodium hydroxide/
carbonate/ silicate.
The following are examples of the specific process for obtaining the long-term stabilized suspension in accordance with the present invention:
A sample of the long-term stabilized suspension was prepared and was divided in three portions.
Each portion was diluted with good quality water in order to obtain concentrations of 1, 2 and 5% in weight.
Adhesion tests were carried out for each sample by covering iron mineral pellets with each portion. An additional adhesion test was carried out using a sample of cement at a concentration of 15% in weight for comparison purposes, as well as another adhesion test using a control sample having no adhesion additives.
The 5 samples were placed inside a laboratory reactor in order to carry out the iron mineral reduction (change of iron oxide to metallic iron) and the following results were obtained:
DMSLegal\053G38\00001\18072G3v1 13 Sample % of clustering Control, without additives 87 Cement suspension at 15 % 30 Stabilized suspension at 5 % 4 Stabilized suspension at 2 % 10 Stabilized suspension at 1 % 19 The best results were obtained with the suspension at 5%, by which a lesser quantity of agglomerated pellets were produced at the reactor exit, and even at a concentration of 1 % there were obtained better results compared to the results obtained with the cement suspension at 15%.
A sample of the long-term stabilized suspension was prepared and divided in six portions.
Two portions were diluted with water in order to obtain a concentration of 2% in weight, another two portions were diluted at a 3% in weight and the last two portions were diluted at a 5% in weight.
Each portion was used to cover iron mineral pellets. Three samples were maintained with concentrations of 2%, 3% and 5%, and three samples were air blew (i.e. dried) in order to eliminate water excess and to determine if the DMSLegal\053G38\00001\18072G3v1 14 adherence to the pellets decreases.
The 6 samples were placed inside a laboratory reactor in order to carry out the iron mineral reduction and the following results were obtained:
Sample % of clustering Stabilized suspension at 2 % 15 Stabilized suspension at 2 % air blew 19 Stabilized suspension at 3 % 11 Stabilized suspension at 3 % air blew 14 Stabilized suspension at 5 % 6 Stabilized suspension at 5 % air blew 11 From the above referred results, It can be concluded that air blowing the samples before placing them inside the reactor, produce a slight decrease of the stabilized suspension performance, but there was always obtained low percentages of agglomerated pellets.
Four samples of the stabilized suspension were prepared, adding a styrene acrylic compound to each sample, in amounts of from between about 2%
to 5% in weight.
The four samples were diluted with water until obtain a final concentration of 5% in weight which were used to cover iron mineral pellets. Subsequently the pellets covered with the stabilized suspension samples were placed inside a DMSLegal\053638W0001\1807263v1 I S
reactor in order to carry out an iron reduction and the following results were obtained. A control sample comprising a cement suspension at a concentration of 15% in weight having no additives, was also evaluated. The following results were obtained:
Sample % of clustering Stabilized suspension with a 2% of additive 14 Stabilized suspension with a 3% of additive 9 Stabilized suspension with a 4% of additive 8 Stabilized suspension with a 5% of additive 8 Cement suspension at 15% without additive 28 From the above experiment it can be concluded that the lesser percentage of remnant agglomerates were obtained with additive amounts of 4% and 5% in weight.
Three samples of the stabilized suspension were prepared, using as a raw material natural magnesite (magnesium carbonate) which was burned at a temperature of 900°C in order to obtain magnesium oxide.
After obtaining the magnesium oxide, water was added to the magnesium oxide in order to obtain magnesium hydroxide and to adjust its concentration at 55% in weight.
DMSLegal\053638\00001\1807263v1 16 The obtained suspension was divided in three portions, adding 1 %, 3%
and 5% in weight of a styrene acrylic compound to each portion respectively.
Finally there was added water in order to obtain a magnesium hydroxide concentration of 5% in weight.
Each sample was used to cover different iron pellets which were placed inside a laboratory reactor in order to carry out an iron reduction at a temperature of 950°C.
Other iron pellets were covered with a cement suspension at a concentration of 15% in weight and placed inside the same reactor in order to use them as control samples. The following results were obtained:
Sample % of clustering Stabilized suspension with 1 % of additive 15 Stabilized suspension with 3% of additive 9 Stabilized suspension with 5% of additive 8 Cement suspension at 15% 26 The best results were obtained with the stabilized suspensions having additive amounts of 3% and 5%. Also there was demonstrated that the stabilized suspension of the present invention may be produced using other different raw materials.
Finally it must be understood that the long term-stabilized suspension, for covering briquettes, particles, pellets or powder iron and the process for its production and application of the present invention, is not limited exclusively to the above described and illustrated embodiments and that the persons having DMSLegal\053638\00001 \18072G3v 1 ordinary skill in the art can, with the teaching provided by this invention, make modifications to the long term-stabilized suspension for covering iron mineral and the process for its production and application of the present invention, which will clearly be within the true inventive concept and scope of the invention which is claimed in the following claims.
DMSLegal\053638\00001 \1807263v 1 18
Claims (22)
1. A long term stabilized suspension, which can be used for covering briquettes, particles, pellets or powder of several kinds of materials for avoiding adhesion between each other and thus the formation of agglomerates when treated at high temperatures having:
a solid content of about 52% to 72%;
a water content of about 28% to 48%;
a viscosity of about 500 to 1,500 cp.;
an average particle size of about 1 to 3 microns;
an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of about 50% to 70% in weight;
a pH value of over 10.5;
an equivalent alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of 34% to 48%;
a specific gravity of 1.4 to 1.6;
at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis and and an adherent compound that improves the adhesion of the suspension to the pellets or briquettes during the process, at a concentration of at least 30%
in an amount of 0.5 to 5% in dry basis;
wherein the long-term stabilized suspension can be stored for at least three months without substantial agitation, and without experiencing substantial settlement and solid hard substrate formations.
a solid content of about 52% to 72%;
a water content of about 28% to 48%;
a viscosity of about 500 to 1,500 cp.;
an average particle size of about 1 to 3 microns;
an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of about 50% to 70% in weight;
a pH value of over 10.5;
an equivalent alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate content of 34% to 48%;
a specific gravity of 1.4 to 1.6;
at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis and and an adherent compound that improves the adhesion of the suspension to the pellets or briquettes during the process, at a concentration of at least 30%
in an amount of 0.5 to 5% in dry basis;
wherein the long-term stabilized suspension can be stored for at least three months without substantial agitation, and without experiencing substantial settlement and solid hard substrate formations.
2. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises magnesium hydroxide.
3. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises magnesium carbonate.
4. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises magnesium silicate.
5. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises calcium hydroxide.
6. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises calcium carbonate.
7. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises calcium silicate.
8. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises aluminum hydroxide.
9. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises aluminum carbonate.
10. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises aluminum silicate.
11. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises sodium hydroxide.
12. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises sodium carbonate.
13. The long term stabilized suspension as claimed in claim 1, wherein the alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprises sodium silicate.
14. The long term stabilized suspension as claimed in claim 1, wherein the anionic polyelectrolyte is selected from the group consisting in sodium polyacrylate and ammonium polystyrene/maleate.
15. The long term stabilized suspension as claimed in claim 1, wherein the adherent compound is selected from the group consisting in styrene acrylic emulsions.
16. The long term stabilized suspension as claimed in claim 1, having a coverage area of 5 m2/g minimum.
17. The long term stabilized suspension as claimed in claim 1, which can be applied on the surface of the briquettes, particles, pellets or powders, as a diluted suspension having a concentration of from 4 to 50% in weight.
18. A process for the production of a long term stabilized suspension using as raw material an alkaline, alkaline-earth or other metal hydroxide, carbonate or silicate comprising:
a) washing the raw material solids;
b) filtering and repulping the raw material solids in order to obtain agglomerated solid particles having less than 0.6% of chloride values;
c) adding at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis.
d) dispersing the agglomerated solid particles in a dispersing equipment;
e) grinding the dispersed product, to reduce the particle size so that at least the 50% of the ground product have a particle size of about 2 microns;
f) adding an compound type styrene acrylic emulsion, at a concentration of at least 30% in an amount of 0.5 to 5% in dry basis; and g) dispersing the product of step f) in a dispersing equipment.
a) washing the raw material solids;
b) filtering and repulping the raw material solids in order to obtain agglomerated solid particles having less than 0.6% of chloride values;
c) adding at least one anionic polyelectrolyte, at a concentration of at least 25%, in an amount of about 0.5 to 2.5% in dry basis.
d) dispersing the agglomerated solid particles in a dispersing equipment;
e) grinding the dispersed product, to reduce the particle size so that at least the 50% of the ground product have a particle size of about 2 microns;
f) adding an compound type styrene acrylic emulsion, at a concentration of at least 30% in an amount of 0.5 to 5% in dry basis; and g) dispersing the product of step f) in a dispersing equipment.
19. The process as claimed in claim 18, wherein the step d) is carried out in a minimum 5 minutes.
20. The process as claimed in claim 18, wherein the step e) is carried out in a sand mill using high density balls, as milling media.
21. The process as claimed in claim 18, wherein the anionic polyelectrolyte is selected from the group consisting in sodium polyacrylate and ammonium polystyrene/maleate.
22
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BRPI0302076-2 | 2003-06-18 | ||
| BR0302076A BR0302076A (en) | 2003-06-18 | 2003-06-18 | A long-term stabilized suspension for iron mineral covering and a process for its production. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2470286A1 true CA2470286A1 (en) | 2004-12-18 |
Family
ID=33557312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2470286 Abandoned CA2470286A1 (en) | 2003-06-18 | 2004-06-07 | A long term-stabilized suspension for covering iron mineral, and a process for its production |
Country Status (5)
| Country | Link |
|---|---|
| AU (3) | AU2003246312A1 (en) |
| BR (1) | BR0302076A (en) |
| CA (1) | CA2470286A1 (en) |
| MX (1) | MXNL04000047A (en) |
| RU (1) | RU2374036C2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007117840A2 (en) * | 2006-03-31 | 2007-10-18 | Albemarle Corporation | Magnesium hydroxide with improved compounding and viscosity performance |
| WO2007117841A2 (en) * | 2006-03-31 | 2007-10-18 | Albemarle Corporation | Magnesium hydroxide with improved compounding and viscosity performance |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR3122875B1 (en) * | 2021-05-14 | 2024-07-19 | Timab Magnesium | Antifoam magnesium hydroxide suspension |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4412844A (en) * | 1979-06-20 | 1983-11-01 | Nalco Chemical Company | Stable oil dispersible magnesium hydroxide slurries |
| US5811069A (en) * | 1997-02-25 | 1998-09-22 | Servicios Industriales Penoles, S.A. De C.V. | Long term-stabilized magnesium hydroxide suspension and a process for its production |
-
2003
- 2003-06-18 BR BR0302076A patent/BR0302076A/en not_active IP Right Cessation
- 2003-09-16 AU AU2003246312A patent/AU2003246312A1/en not_active Abandoned
-
2004
- 2004-06-07 CA CA 2470286 patent/CA2470286A1/en not_active Abandoned
- 2004-06-16 RU RU2004118102/02A patent/RU2374036C2/en not_active IP Right Cessation
- 2004-06-18 MX MXNL04000047 patent/MXNL04000047A/en unknown
-
2006
- 2006-06-16 AU AU2006202581A patent/AU2006202581B2/en not_active Ceased
-
2009
- 2009-02-20 AU AU2009200667A patent/AU2009200667A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007117840A2 (en) * | 2006-03-31 | 2007-10-18 | Albemarle Corporation | Magnesium hydroxide with improved compounding and viscosity performance |
| WO2007117841A2 (en) * | 2006-03-31 | 2007-10-18 | Albemarle Corporation | Magnesium hydroxide with improved compounding and viscosity performance |
| WO2007117841A3 (en) * | 2006-03-31 | 2007-12-06 | Albemarle Corp | Magnesium hydroxide with improved compounding and viscosity performance |
| WO2007117840A3 (en) * | 2006-03-31 | 2007-12-13 | Albemarle Corp | Magnesium hydroxide with improved compounding and viscosity performance |
Also Published As
| Publication number | Publication date |
|---|---|
| RU2374036C2 (en) | 2009-11-27 |
| AU2003246312A1 (en) | 2005-01-13 |
| RU2004118102A (en) | 2006-01-10 |
| AU2006202581A1 (en) | 2006-07-06 |
| AU2006202581B2 (en) | 2009-03-05 |
| BR0302076A (en) | 2005-03-22 |
| MXNL04000047A (en) | 2005-06-21 |
| AU2009200667A1 (en) | 2009-03-12 |
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