CA2141787C - Binder composition and process for agglomerating particulate material - Google Patents
Binder composition and process for agglomerating particulate material Download PDFInfo
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- CA2141787C CA2141787C CA002141787A CA2141787A CA2141787C CA 2141787 C CA2141787 C CA 2141787C CA 002141787 A CA002141787 A CA 002141787A CA 2141787 A CA2141787 A CA 2141787A CA 2141787 C CA2141787 C CA 2141787C
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- 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
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- 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
- C22B1/244—Binding; Briquetting ; Granulating with binders organic
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Abstract
The present invention generally relates to a process of agglomerating particulate material in the presence of water which comprises mixing said particulate material with a binding effective amount of at least one water soluble polymer, and a binder enhancing effective amount of caustic, to produce a mixture, and forming said mixture into agglomerates. The invention also relates to a binder composition useful for the agglomeration of particulate material in the presence of water which comprises a binding effective amount of a water-soluble polymer and a binder enhancing effective amount of caustic.
Description
BINDER COMPOSITION AND PROCESS FOR AGGLOMERATING
PARTICULATE MATERIAL
BACKGROUND OF THE INVENTION
", The present invention relates to a novel binder composition for agglomerating particulate materials, a novel process for agglomerating particulate materials u,'sing said binder composition, and to the agglomerated products produced from said process. The process is particularly useful for agglomerating metallic ores such as iron ore.
Agglomeration i commercially used in industries where materials are encountered in-a form which is too finely .15 divided for convenient processing or handling. Thus, there is a need to upgrade the size, density and/:or uiniformity of finely d~.vided particles for more efficient handling, processing or recovery. Agglomeration is particularly useful in the metal refining industry, where the concentrate ore .~ZO' encountered is typically finely divided:
Many processes for the agglomeration of particles, especially metallic particles, are known in the art. In the mining industry it is common practice to'agglomexate or 25~= pelletize ffinely ground mineral ore concentrate to facilitate shipping of the ore. After the mineral ore has been mined, it 'is frequently wet ground, though not always the case, and screened to remove large particles which can be recycled for further grinding: The screened mineral'ore is known in the 30 art 'as ~~concentrate~~
After screening:, a binding agent is added to the wetted mineral ore concentrate and the binder/mineral ore composite K is conveyed to a balling: drum or other means for',pelletizing ~,~5 the ore: The binding agent serves to hold or bind the mineral ore together until after firing. After he balling drum operation, the pellets are formed, but they are still wet.
PARTICULATE MATERIAL
BACKGROUND OF THE INVENTION
", The present invention relates to a novel binder composition for agglomerating particulate materials, a novel process for agglomerating particulate materials u,'sing said binder composition, and to the agglomerated products produced from said process. The process is particularly useful for agglomerating metallic ores such as iron ore.
Agglomeration i commercially used in industries where materials are encountered in-a form which is too finely .15 divided for convenient processing or handling. Thus, there is a need to upgrade the size, density and/:or uiniformity of finely d~.vided particles for more efficient handling, processing or recovery. Agglomeration is particularly useful in the metal refining industry, where the concentrate ore .~ZO' encountered is typically finely divided:
Many processes for the agglomeration of particles, especially metallic particles, are known in the art. In the mining industry it is common practice to'agglomexate or 25~= pelletize ffinely ground mineral ore concentrate to facilitate shipping of the ore. After the mineral ore has been mined, it 'is frequently wet ground, though not always the case, and screened to remove large particles which can be recycled for further grinding: The screened mineral'ore is known in the 30 art 'as ~~concentrate~~
After screening:, a binding agent is added to the wetted mineral ore concentrate and the binder/mineral ore composite K is conveyed to a balling: drum or other means for',pelletizing ~,~5 the ore: The binding agent serves to hold or bind the mineral ore together until after firing. After he balling drum operation, the pellets are formed, but they are still wet.
2 ~. ~ 1'~ 8'~
These wet pellets are commonly referred to as "green pellets"
or "green balls". These green pellets are thereafter transported to a kiln and heated in stages to a end temperature of about 2400°F.
.' For many years, bentonite clay was the binding agent of choice in the pelletizing operations for mineral ore concentrates. Use of bentonite as a binding agent produces balls or pellets having a very good wet and dry strengths and also provides a desired degree of moisture control. Use of bentonite does,~however, have several disadvantages.
Initially,, bentonite adds to the silica content of the pellets when the ore pellets are fired at, a temperature of 2400°F or higher. Higher amounts of silica are not desirable because silica decreases the efficiency of blast furnace operations used in smelting the ore.
The use of bentonite to form pellets of mineral ore concentrates can also add alkalis which are oxides of, for example, sodium and potassium. The presence of arkalis in the blast furnace causes both the pellets and coke to deteriorate and to form scabs on the furnace wall, which increases fuel consumption and decreases the productivity of the smelting operation.
Organic binders have proven to be an attractive alternative to bentonite because organic binders do not increase the silica content of the ore and they impart physical and mechanical properties to the pellets comparable with those of bentonite. Organic binders also burn out during ball firing operations thus causing an increase in the microporosity of the pellets. Accordingly, the: pore volume and surface/mass ratio of the formed pellets produced using organic binders is larger than that of pellets produced using bentonite. Due to the larger surface area and increased permeability of the pellets produced using organic binders, WO 94/03fs48 ~ ~ ~ PGT/US92/06551 the reduction of metallic oxides such as iron oxide is more efficient than with pellets prepared with bentonite.
Examples of some commonly mentioned organic binders include polyacrylate, polyacrylamide and copolymers thereof, methacrylamide, polymethacrylamide, cellulose derivatives such as alkali metal salts of carboxymethyl cellulose and carboxymethylhydroxyethyl cellulose, poly (ethylene oxide), guar gum, dairy wastes, starches, dextrins, wood related products, alginates, pectins, and the like.
U. S. Patent No. 4,751,259 discloses compositions for iron ore agglomeration which comprise 10-45% by weight of a water-in-oil emulsion of a water soluble vinyl addition polymer, 55-90% by weight of a polysaccharide, .001 - 10% by weight of a water soluble surfactant and 0-15 weight % of Borax.
U. S. Patent No. 4,948,430 discloses a binder for the agglomeration of ore in the presence of water, which comprises 10% - 90% of a water soluble sodium carboxymethylhydroxyethyl cellulose and 10% to 90% of sodium carbonate.
U. S. Patent No. 4,288,245 discloses pelletization of metallic ores, especially iron ore, with carboxymethyl cellulose and the salt of a weak acid.
U. S. Patent No. 4,863,512 relates to a binder for metallic containing ores which comprises an alkali metal salt .of carboxymethyl cellulose and sodium tripolyphosphate.
European Patent Application Publication No. 0 376 713 discloses a process for making pellets o~f particulate metal ore, particularly iron ore. The process comprises mixing a water-soluble polymer with the particular metal ore and water and pelletizing the mixture. The water-soluble polymer may be of any typical type, e.g., natural, modified natural or
These wet pellets are commonly referred to as "green pellets"
or "green balls". These green pellets are thereafter transported to a kiln and heated in stages to a end temperature of about 2400°F.
.' For many years, bentonite clay was the binding agent of choice in the pelletizing operations for mineral ore concentrates. Use of bentonite as a binding agent produces balls or pellets having a very good wet and dry strengths and also provides a desired degree of moisture control. Use of bentonite does,~however, have several disadvantages.
Initially,, bentonite adds to the silica content of the pellets when the ore pellets are fired at, a temperature of 2400°F or higher. Higher amounts of silica are not desirable because silica decreases the efficiency of blast furnace operations used in smelting the ore.
The use of bentonite to form pellets of mineral ore concentrates can also add alkalis which are oxides of, for example, sodium and potassium. The presence of arkalis in the blast furnace causes both the pellets and coke to deteriorate and to form scabs on the furnace wall, which increases fuel consumption and decreases the productivity of the smelting operation.
Organic binders have proven to be an attractive alternative to bentonite because organic binders do not increase the silica content of the ore and they impart physical and mechanical properties to the pellets comparable with those of bentonite. Organic binders also burn out during ball firing operations thus causing an increase in the microporosity of the pellets. Accordingly, the: pore volume and surface/mass ratio of the formed pellets produced using organic binders is larger than that of pellets produced using bentonite. Due to the larger surface area and increased permeability of the pellets produced using organic binders, WO 94/03fs48 ~ ~ ~ PGT/US92/06551 the reduction of metallic oxides such as iron oxide is more efficient than with pellets prepared with bentonite.
Examples of some commonly mentioned organic binders include polyacrylate, polyacrylamide and copolymers thereof, methacrylamide, polymethacrylamide, cellulose derivatives such as alkali metal salts of carboxymethyl cellulose and carboxymethylhydroxyethyl cellulose, poly (ethylene oxide), guar gum, dairy wastes, starches, dextrins, wood related products, alginates, pectins, and the like.
U. S. Patent No. 4,751,259 discloses compositions for iron ore agglomeration which comprise 10-45% by weight of a water-in-oil emulsion of a water soluble vinyl addition polymer, 55-90% by weight of a polysaccharide, .001 - 10% by weight of a water soluble surfactant and 0-15 weight % of Borax.
U. S. Patent No. 4,948,430 discloses a binder for the agglomeration of ore in the presence of water, which comprises 10% - 90% of a water soluble sodium carboxymethylhydroxyethyl cellulose and 10% to 90% of sodium carbonate.
U. S. Patent No. 4,288,245 discloses pelletization of metallic ores, especially iron ore, with carboxymethyl cellulose and the salt of a weak acid.
U. S. Patent No. 4,863,512 relates to a binder for metallic containing ores which comprises an alkali metal salt .of carboxymethyl cellulose and sodium tripolyphosphate.
European Patent Application Publication No. 0 376 713 discloses a process for making pellets o~f particulate metal ore, particularly iron ore. The process comprises mixing a water-soluble polymer with the particular metal ore and water and pelletizing the mixture. The water-soluble polymer may be of any typical type, e.g., natural, modified natural or
3 synthetic . The mixture may optionally comprise a palletizing a id which may be sodium citrate.
Organic binder compositions, such as those mentioned above, are not, however, without their own disadvantages.
While they are effective binders, they generally do not impart adequate dry strength to the pellets at economical use levels.
Thus, there is an ongoing need for economical binders with improved properties.
l0 SUMMARY OF THE INVENTION
The present invention generally relates to a process for agglomerating particulate material in the presence of water which comprises mixing said particulate materia 1 with a binding a ffective amount of at least one water soluble polymer, and a binder enhancing effective amount of caustic to produce a mixture, and forming said mixture int o agglomerates.
In another embodiment, the present inventi on contemplates a binder composition useful for the agglomeration of particulate material in the presence of water which comprises a binding effective amount of at least one water soluble polymer and a binder enhancing effective amount of caustic.
In another embodiment, the present invention contemplates a process for agglomerating material comprising:
a) pretreating said particulate material with a binder enhancing effective amount of a liquid spray of a source of hydroxide ions;
b) mixing said pretreated particulate material with a binding effective amount of a water-soluble polymer and water; and c) forming said mixture into agglomerates.
Organic binder compositions, such as those mentioned above, are not, however, without their own disadvantages.
While they are effective binders, they generally do not impart adequate dry strength to the pellets at economical use levels.
Thus, there is an ongoing need for economical binders with improved properties.
l0 SUMMARY OF THE INVENTION
The present invention generally relates to a process for agglomerating particulate material in the presence of water which comprises mixing said particulate materia 1 with a binding a ffective amount of at least one water soluble polymer, and a binder enhancing effective amount of caustic to produce a mixture, and forming said mixture int o agglomerates.
In another embodiment, the present inventi on contemplates a binder composition useful for the agglomeration of particulate material in the presence of water which comprises a binding effective amount of at least one water soluble polymer and a binder enhancing effective amount of caustic.
In another embodiment, the present invention contemplates a process for agglomerating material comprising:
a) pretreating said particulate material with a binder enhancing effective amount of a liquid spray of a source of hydroxide ions;
b) mixing said pretreated particulate material with a binding effective amount of a water-soluble polymer and water; and c) forming said mixture into agglomerates.
4 DETAILED DESCRIPTION OF THE INVENTION
The present invention generally relates to a process of agglomerating particulate materials, especially metal containing ores, in the presence of water. The process comprises mixing said particulate material with a binding effective amount of at least one polymer and a binder enhancing effective amount of caustic to produce a mixture, and thereafter or contemporaneously forming said mixture into agglomerates.
In the context of the present invention, the present inventors have found that the addition of caustic, in either liquid Or powdered form, to the mineral ore, as an integral 4a WO 94/03648 ~ ~ ~ R ~ PCT/US92/06551 part of the organic binder or as a separate entity, unexpectedly provides a synergistic effect in the pelletization process, giving the resultant pellets superior wet drop numbers and dry crush strength compared to pellets formed without the use of caustic. This increase in performance obtained by the addition of caustic allows the user to effectively reduce the amount of organic:binder required thus significantly reducing total binder cost.
The terra "agglomerated" or "agglomeration" as used in the contextof he present invention shall mean the'processing of finely divided materials, whether in powder, dus'~, chip, or other particulate form, to for:a pellets, granules, briquettes, and the like:
The particulate material which may be agglomerated in accordance with this present invention may be almost any finely divided material including metallic minerals or ore.
The predominant metal component in said ore may-, be iron, 2r0 chrome, copper, nickel, zinc, lead, uranium, borium and he dike. kiixtures of the above materials or any other metal occurring in the free or molecularly combined material state asa mineral, or any combination of the above, or other metals, or metal containing ores capable of pelletization, may 2'5- be agglomerated in accordance with the present invention. The present invention is particularly well adapted for the agglomeration of materials containing iron, including iron ore deposits, ore tailings,'cold and hot fines from a sinter process or aqueous iron'ore concentrates from natural sources 30 or recovered from various processes: Iron ore,or any of a wide variety of the'following minerals may for:a a part of the material to be agglomerated: taconite, magnetite, hematite, limonite, goethite, siderite, franklinite,, pyrite, chalcopyrite, chromite, ilmenite and the like.
Minerals other than-metallic minerals which may be agglomerated in accordance with the invention include r' WO 94/03648 ~ ~ ~ ~ ~ t PCTlUS92l06551 phosphate rock, talc, dolomite, limestone and the like. Still other materials which may be agglomerated in accordance with the present invention include fertilizer materials such as .potassium sulfate, potassium chloride, double sulfate of potassium and magnesium; magnesium-oxides animals feeds such ..
as calcium phosphates: carbon black: coal fines; catalyst mixtures; glass batch mixtures; borates, tungsten carbide;
refractory gunning mixes; antimony, flue dust from, for example, power generating plants, solid fuels such as coal, coke or charcoal, blast furnace fines and the like.
The water-soluble polymers) useful in the present invention include but are not limited to:
(1) Water-soluble natural polymers such as guar gum, starch, alginates, pectins, xanthan gum, dairy wastes, wood related products, lignin and the like;
(2), Modified natural polymers such as guar derivatives (e. g. hydroxypropyl guar, carboxymethyl guar, carboxymethylhydroxypropyl guar), modified starch (e. g.
anionic starch, cationic starch), starch derivatives (e. g.
dextrin) and cellulose derivatives such as alkali metal salts of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylhydroxyethyl cellulose, methyl cellulose, lignin derivatives (e. g. carboxymethyl lignin) and the like; and/or (3) Synthetic polymers (e.g. polyacrylamides such as partially hydrated polyacrylamides; polyacrylates and copolymers thereof; polyethylene oxides, and the like).
The foregoing polymers may be used alone or in various combinations of two or more polymers. Water-soluble anionic polymers are a preferred class of polymers to be employed in the present invention.
Preferred polymers for use in the present invention are alkali metal salts of carboxymethyl cellulose. Any substantially water-soluble alkali metal salt of carboxymethyl cellulose may be used in this invention. The sodium salt is, however, preferred. Alkali metal salts of carboxymethyl cellulose, more particularly sodium carboxymethyl cellulose, are generally prepared from alkali cellulose and the respective alkali metal salt of monochloroacetic acid.
Cellulose which is used in the manufacture of sodium ,.
carboxymethyl cellulose is generally derived from wood pulp or cotton linters, but may be derived from other sources such as sugar beet pulp, bagasse, rice hulls, bran, microbially-derived cellulose, and waste.cellulose e.g. shredded paper).
The sodium carboxymethyl cellulose used in the present :invention generally has a degree of substitution ',(the average number of carboxymethyl ether groups per repeating anhydroglucose chain unit of the cellulose molecule) of from about 0.4 to about 1.5, more preferably about 0.6, to about 0.9, and most preferably about 0.7: Generally the average degree of polymerization of,the cellulose furnish is from about 50 to about 4000: Polymers having a degree of polymerization on the higher end of the, range are preferred.
It is more preferred to use sodium carboxymethyl'cellulose having a Brookfield.viscosity in a 1% aqueous solution of more than'2000 cps at:30 rpm, spindle #4. Still more preferred is sodium carboxy~nethyl cellulose having a 8rookfield viscosity in a i% aqueous solution of more than about 4,004 cps at 30 rpm spindle #4.
A series of commercially available binders containing sodium carboxymethyl cellulose especially useful in the present nvention is marketed by the Dreeland, Inc. of Virginia, lit, Denver;, CO, and Akzo Chemicals ofnAmersfoort, the Netherlands,; under the trademark Peridu~.
The "binding effective amount of polymer" will vary depending upon numerous factors known to 'the skilled artisan.
Such factors include, but are not limited to, the type of ~5 particulate material to be agglomerated or pelletized, the moisture'content of the particulate material, particle size, the agglomeration equipment utilized, and the desired WO 94/03648 ~ ~ ~ ~~ PCT/US92/06551 properties of the final product, e.g. dry strength (crush , drop number, pellet size and smoothness. Though not limiting, a binding effective amount of polymer will typically be in the range of between about 0.01% to 1% by weight based on the dry weight of the mixture of particulate material, polymer and ' caustic. Preferably, the polymer is present in a range of between about 0.01 to 0.4% by weight, and most preferred, about 0.04%.
As used herein, the term "caustic" shall mean any source of hydroxide ions (OH-) including, but not limited to sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, mixtures thereof and the like. Sodium hydroxide, commonly known as caustic soda, is the most preferred caustic.
A "binder enhancing effective amount of caustic" depends on.the same factors as does the binding effective amount of polymer. Without wishing to be bound to any particular ZO limitation, a binding effective amount of caustic will typically be in the range of between about .004% to .15% by weight based on the dry mixture of particulate material, polymer and caustic. Preferably, caustic ~is present in the range of between about .O1% to .04% by weight, and most preferred at about .03% by weight.
In another embodiment, the present invention contemplates a process of agglomerating particulate material in the presence of water which comprises mixing said particulate material with between about 0.01% to 1% by weight of at least one water soluble polymer selected from hydroxyethyl cellulose, alkali metal salts of carboxymethyl cellulose, methyl cellulose, methylhydroxyethyl cellulose and mixtures thereof, and .004% to .15% by weight of sodium hydroxide to produce a mixture, and forming said mixture into agglomerates.
WO 94/03648 2 ~ ~ ~ R ~ PGTlUS9Z/06551 In still another embodiment, the present invention contemplates a process of agglomerating iron ore wherein said ore is mixed with between about 0.01 to 0.4% by weight of an alkali metal salt of carboxymethyl cellulose, from about 0.01 to .04% by weight sodium hydroxide, and from about 0.02-0.5 wt% (based on dry ore) of soda ash, to produce a mixture, and forming said mixture into agglomerates.
Agglomerated particulate materials formed from any of the l0 foregoing processes is also deemed to be within the scope of the present invention.
The present invention also contemplates a binder composition useful for the agglomeration of particulate materials. The binder composition comprises a binding effective amount of at least one water soluble polymer, and a binder enhancing effective amount of caustic.
In a preferred embodiment, the present invention contemplates a binder composition which comprises between about 10% to 95% by weight of a water soluble polymer and between about 2% to 50% by weight of caustic (wt% binder composition).
In another preferred embodiment, the present invention contemplates a binder composition useful for the agglomeration of iron ore in the presence of water which comprises between about 45% to 95% by weight of a water-soluble alkali metal salt of carboxymethyl cellulose and l0% to 40% by weight of sodium hydroxide.
In yet another embodiment, the present invention contemplates a binder composition whichcomprises between about 50% to 80% by weight of an alkali metal salt of carboxymethyl cellulose, between about 10% to 35% by weight of caustic, and between about 2% to 20% bx weight of a salt of a weak acid, such as sodium citrate and or soda ash.
WO 94/03648 ~~ ' PCT/US92/06551 The binder composition of the present invention may also contain other substances, for instance, those that are formed as by-products in the preparation of the alkali metal salt of carboxymethyl cellulose, such as sodium chloride and sodium glycolate, as well as other polysaccharides or synthetic ", water-soluble polymers and other "inorganic salts" (for want of a better term sodium carbonate, sodium citrate, and the Like are referred to as "inorganic salts" herein). Exemplary polysaccharides include,'e:g., hydroxyethyl cellulose,.
hydroxypropyl cellulose, carboxymethylhydroxyethyl cellulose , methyl'cellulose, hydroxypropyl methyl cellulose, guar, hydroxpropyl guar and sugar. beet pulp, and the like.
Exemplary synthetic water-soluble polymers include partially hydrated polyacrylamide, polyvinyl alcohol, styrene/maleic anhydride copolymers, and polyacrylate and copolymers thereof, etc. Exemplary inorganic salts include; e. g. the salts described by Roorda in U. S. Patent Nos.4,288,245 and 4,597,797 such as sodium citrate, soda ash, and'the like.
The ratiosof polymer, e.g. alkali metal salt of carboxymethyl cellulose, caustic and water to particulate material, e.g.:concentrated ore are'dependent on various factors including the agglomeration method used, the material to be agglomerated.and th,e desired properties of the agglomerates to be prepared: A,person of ordinary skill in the art can readily detenaine the specific amounts that will be most suitable for individual circumstances.: Pelletization is generally carried out using;the binder comp4sition in an amount of from about 0.0044% to about 0.44%, preferably from about '0.022% to about 0.22% (by weight of the total dry mixture), of the binder composition and about 2% to about 20%, preferably about 5% to about 15%, water, by weight of the total dry mixture. In addition to the binder composition, clays'such as bentonite clay may be used in pelletization.
The total amount of these clays will depend on the user's objectives, but will generally be less than 0.22%, based on the weight of the total dry mixture:
WO 94/03648 2 ~ ~ 1 ~ ~ ~'~ PGT/US92/06551 Any known method for forming dry pellets or particles can be used to prepare the agglomerates of this invention. For instance, the concentrated ore may be agglomerated into particles or agglomerates by rotating the concentrated ore powder in a drum or disc with a binder and water, followed by drying and firing. Agglomerates can also be formed by '~
briquetting, nodulizing, or spray drying.
Addition of the binder composition constituents may be carried out in any manner commonly applied in the art. For' instance, the binder constituents may be mixed as solid matter with the concentrated ore in a dry or liquid form or as an emulsion or dispersion. Further, they may be simultaneously, successively or alternatively added to the concentrated ore before or during the pelletizing treatment. In a preferred method, Ziquid caustic is sprayed on moist concentrated ore resulting from the aforementioned separation process, which has all but about 10 wt% of the water removed by, e.g.
rotating disc filter. At a sufficient,point upstream from the agglomerating drum or disc, the polymeric binder composition is applied so that the binder components and concentrated ore are well mixed aad adequately hydrated prior to being formed w into green pellets. As non-limiting ranges, the water content should generally be in the range of about 4 to 30 wt% based on the weight of dry particulate matter and most preferably between about 7 and 12 wt%.
Other substances may also be optionally added to the binder composition of the present invention. For example, in iron ore pelletizing operations, small amounts of flux, e. g., limestone or dolomite may also be added to enhance mechanical properties of the pellets. The flux also helps to reduce the dust level in the indurating furnace when the pellets are fired. Olivine, serpentine, magnesium and similar minerals may be used to improve metallurgical properties of the pellets.
WO 94/03648 2, ~. ~ ~~ ~ PCT/US92/06551 Drying the wet balls and. firing the resultant dry balls may be carried out as one continuous or two separate steps.
The important factors are that the balls must be dry prior to ' firing as the balls will degrade or spall if fired without first drying them. It is therefore preferred that the balls ."
be heated slowly to a temperature of. at least about 2200'F, preferably to at least about 2400°F and then fired at that temperature. In another embodiment, they are dried at low temperatures, preferably by heating, or alternatively, under ambient conditions, and then fired at a temperature of at least about 2200'F, more preferably at about 2400'F. Firing is carried out for a sufficient period of time to bond the small particles-into-pellets with enough strength, to enable transportation and/or further handling, generally'about 15 minutes to about 3 hours.' The, process of the present invention; is preferably employed with concentrated iron ore. This process' is also suitablefor non-ferrous concentrated ores such a's ores of zinc, lead, tin, nickel and chromium and oxidic materials such as silicates and quartz, and sulphidicmaterials.' As a practical matter, this .invention is intended foruse in binding the concentrated ores which result-from separation of the host rock from the ore removed from the ground. However, it can also be used to bind natural ores.
The pellets resulting from this'process are dry, hard agglomerates having sizes-that are suitable for,''e. g.
shipping, handling, sintering,-etc. Pellets generally have 30. an average diameter of about i/4 to about l inch, preferably about 1/2 inch. Pellet size~is generally a function of the user and operator's preference, more than of binding ability of the compositions of this invention and~virtually any size pellet desired by blast furnace operations and mine operations :35: can be prepared:
The invention is further described by the following non-limiting examples. For the purpose of characterizing the agglomerates formed, use is made of the following procedure and test protocol.
..
AGGLOMERATE FORMATION
The process was begun by placing 2500 grams (calculated as dry weight) of iron ore concentrate (moisture content approximately 9 to 10 wt. %) into a Mullen Mixer (Model No. 1 Cincinnati Muller, manufactured by National Engineering Co.).
Caustic was thereafter evenly sprayed on the iron ore in liquid form, diluted from either a 10 Normal solution or sodium hydroxide pellets (97~%), both purchased from Fisher Scientific. The addition rate of the diluted caustic was carefully monitored and represented in the examFles as pounds dry caustic added per long ton dry concentrate (#/LTDC).
After caustic addition, polymer is then added to the mixer and spread evenly over the iron ore concentrate. If a mixture of polymers was used, the mixture was premixed by hand prior to addition to the muller mixer. The loaded mixer was run for three (3) minutes to evenly distribute the polymer.
The resulting concentrate mixture was screened to remove particles smaller than those retained on an 8 mesh wire screen.
A balling disc fabricated from an airplane tire (approx.
16" diameter) driven by a motor having a 60 RPM rotational speed was employed to produce green balls of the concentrate mixture. Pellet "seeds" were formed by placing a small portion of the screened concentrate mixture in the rotating balling tire and adding atomized water to initiate seed growth. As the size of the seed pellets..approached 4 mesh, they were removed from the balling disc and screened. The seed pellets with a size between 4 and 6 mesh were retained.
This process was repeated if necessary until 34 grams of seed pellets were collected.
WO 94/03648 2, ~~" ~ ~~ ~ ~ PCf/US92/06551 Finished green balls were;produced by placing the 34 grams of seed pellets of size between 4 and 6 mesh into the rotating tire of the balling disc and adding portion of the .remaining concentrate mixture from the muller mixer over a 4 minute growth period. Atomized water was added if necessary.
M
When the proper size was achieved (-0.530 inch, +0.500 inch) concentrate mixture addition ceased and the pellets were allowed a 30 second finishing roll. The agglomerated pellets were removed from the disc, screened to -0.530, +0.500 inch size and stored in an air-tight container until they were tested.
Test Protocol Wet DroQ Number was determined by repeatedly dropping two groups of ten (l0) pellets each from an 18 inch height to a steel plate until a crack appeared on the surface of each pellet. The number of drops xequired to produce a crack on the surface of each pellet was recorded. The average of all pellets was taken to determine the drop number of each 20 agglomerated mixture.
Crush Strength was determined by drying twenty (20) pellets of each agglomerated mixture to measure the moisture content. The dry pellets were then individually subjected to a Chatillon Spring Compression Tester, Model LTCM,(25 pound range) at a loading rate of O.l inch/second. The dry strength report for each agglomerate mixture is the average cracking pressure of the twenty pellets.
The following samples demonstrate processes and the binders of the present invention employing various polymers with sodium hydroxide and other OH', as binding agents for particulate material, which is iron ore unless otherwise specified.
WO 94/03648 ~ "~ ~ ! ~'~ ~ *~ PCT/US92/06551 .
Example 1 In this example,a pure sodium carboxymethyl cellulose (CMC) polyme r binderwas employed (Peridu~30oZ)with and without the additionof caustic. Table l, below clearly shows that the per formanceof the pure CMC binder tremendously is improved by the addition ic.
of caust PURE CMC NaOH Moisture Wet Drop Dry Crush #/LTDC #/LTDC ( ~s ) 1.0 ___ 9.9 8.2 5.3 1.0 .12 10.3 10.5 7.7 1.0 .24 10.1 11.1 10.6 1.0 1.2 10.0 9.5 '11.9 1.0 2.4 9.7 7.3 8.8 1.0 4.0 9.2 5.6 8.0 # = Pounds LTDC = Long ton dry concentrate The data of Table l clearly show that the perfonaance of pure CMC is greatly enhanced by the addition of NaOH. Tn this case, there is an optimum level of NaOH addition at between about .24 to l.2 #/LTDC. When excessive amounts of caustic are added, the wet drops start to decrease, probably from binder deterioration at higher pH levels.
example 2 A technical grade up to out 25% salt CMC containing ab byproducts (Peridur 200~)was also tested and without the with addition of caustic. Table 2, below, contains the data.
Technical Grade CMC NaOH Moisture Wet Drops Dry Crush #/LTDC #LTDC C ~s ) ~
,g0 ___ 10.2 6.6 1.7 .90 .12 10:5 7.9 2.1 .90 .24 10.4 8.5 3.2 .90 1.2 10.1 8.9 7.5 .90 2.4 10.1 8.4 7.2 WO 94!03648 ~ ~ ~ ~ ~ ~ ~ PCT/US92/06551 '-The data clearly shows that the addition of caustic greatly improves the performance of the technical grade CMC. Like the pure grade CMC of Example 1, there is an optimum level of caustic addition wherein product performance peaks, and thereafter slowly deteriorates beyond optimum addition levels.
Examt~le 3 A CMC/soda ash combination was employed with and without the addition of NaOH. The CMC/soda ash combination consists of about 70 to 85% technical grade CMC and 15-30% soda ash.
The data obtained is compiled in Table 3, below.
Technical Grade CMC/Soda Ash Add'n NaOH Moisture Drop # Dry Crush #/LTDC #/LTDC
(lbs) Peridu~ 2.15 1.06 --- 10.0 7.1 3.7 2.15 ~ 1.06 .12 10.0 7.5 5.0 2.15 1.06 .24 10.2 9.0 5.8 2.15 1.06. 1.2 10.0 8.2 7.8 2.15 1.06 2.4 9.9 7.0 7.4 Peridu~3.15 1.0 --- 9.5 4.6 2.2 3.15 1.0 .24 9.7 5.4 5.2 3.15 1.2 --- 9.5 5.0 3.0 3.15 1.2 .24 9.? 6.4 7.2 Periduz~3.30 1.0 --- 9.4 4.3 2.7 3.30 1.0 .24 9.6 4.7 5.2 3.30 1.2 -- 9.2 4.5 4.2 3.30 1.2 .24 9.6 6.1 6.7 *Periduz~ 2.15, Peridu~3.15 and Peridu~3.30 are binder 40. compositions commercially available from Dreeland, Inc., Virginia, MN, Denver CO, and Akzo Chemicals, Amersfoort, the Netherlands.
The data clearly show that in every instance of caustic addition, there was an improvement in the pellet quality as compared to the pellets formed with no caustic addition.
WO 94/03548 ~ ~ ~ ~ ~ ~ PCT/US92/06551 Example 4 In this trial, applicants tested a series of anionic polymers, including polymers of polyacrylamide (PL1400~).
POLYACRYLATE (FP 1000 , CM GUAR carboxymethyldihydroxypropyl cellulose (CMDHPC), carboxymethylhydroxyethyl cellulose M
(CMHEC); and, Stabilos~ LV, a carboxymethyl starch (CM
Starch) with and without caustic addition. The data is tabulated in Table 4 below.
Product Add'n NaOH Moisture Drop # Dry Crush #/LTDC #/LTDC
(lbs) PAM (PL 1.1 --- 14.8 5.5 1.6 1400)~
PAM (PL 1.1 .24 11.3 6.9 1.9 1400) PAM (PL 1.1 1.2 11.0 7.2 3.4 1400) PAA (FP 1.0 ._- 9.1 2.9 2.5 10f~) PAA (FP 1:0 1.2 9.3 2.9 5.3 100) CM-GUAR 1.0 --- 20.0 7.0 1.7 CM-GUAR 1.0 .12 10.2 8.8 2.3 CM-GUAR 1.0 .24 10:1 6.9 2.?
CM=GUAR 1.0 .43 9.9 7.7 3.1 CM-GUAR 1.0 .72 9.9 3.2 2.3 CM-GUAR 1.0 1.2 9.4 2.3 2.0 CMDHPC 1.0 --- 8.9 2.7 1.3 CMDHPC 1.0 .24 9.1 2.6 1.7 , CMHEC 1.0 --_ 9.2 3.6 1.4 CMHEC 1.0 .24 9.6 4.2 2.4 SEC 1.0 1.2 9:5 3.5 3.6 CM-Starch 2.0 --- 9.7 3.3 3.3 CM-Starch 2.0 .48 9.8 4.3 7.1 * PL1400'~ polyacrylamide commercially available from is a Stockhaus en, Inc.
* FP100~ polyacrylate is a commercially available from Polyacryl Inc.
* HP-8 s produced sold Hi-Tek Polymers.
i and by * Guar available 5200 is through Economy Mud Products.
The polyacrylamide the polyacrylate (PL1400s), (FP100e), 5p CMDHPC, and CM- Starch showed benefits CNgiPC, throughout the WO 94/03648 ~ ~~~ ~'~ PCT/US92/06551, addition of caustic. This was not the case with the CM-Guar.
Small additions of caustic significantly improved performance, however when the dosage of caustic increased was beyond optimum levels, both the wet and dry trengths weredestroyed.
s w Example 5 Non-ionic polymers have also beenconsidered for use a binders: These pollrmers incl ude, but are not limited to hydroxyethyl cellulose (HEC), methyl hydroxyethyl cellulose (Meth. HEC), hydroxypropyl ce llulose HPC), starch,dextrin, ( guar (guar 5200), and hydroxypropyl' stic guar (HPG). Cau addition to these binders was also investigated, the data and is tabulated in Table 5, below.
,15 TABLE 5 Polymer Add'n NaOH Moi ture Drop # Dry Crush #/LTDC #/LTDC (lbs) HEC / T.0 96 7.7 2.9 HEC 1.0' .24 9.9 11.1 3.4 HEC 1.0 1.2 10,1 10.7 3.6 Meth.HEC 1.0 g7 5:9 4:3 Meth.HEC 1.0 .24 9.9 7.0 4:6 25, 4 HPC 1.0 9:9 6.1 2E
HPC 1.0 .24 10:9 6.7 3.0 Starch 4:0 9.8 4.1 5.8 3 0 Starch 40 .24. 101 4.7 5.7 Dextrin 4.0 8.5 2.5 4:9 Dextrin 4.0 :24 g2 2.8 4.8 35 Guar 5200 1.0 10.7 4:6 1.8 Guar 5200 1.0 .24' 9:7 3.8 1.4 HPG (IiP8 ) 1. 0 --_- 113 7 . 7 2 , p HPG (HP8) 1:0 .24 95 2:7 ' 1,5 The data clearly demonstrate that the cellulos3cs all showed some improvement, albeit the improvements as great as were,not .fir ~~ 4:5 those seen with anionic binders:
The starch and dextrin binders tested showed no improvement in wet drop numbers and dry strengths.
Example 6 To determine whether or not caustic itself may be contributing to the dry strength of pellets by forming its own binder bridges, iron ore was pelletized using only caustic.
The data is compiled in Table 6 below.
NaOH Add'n Moisture Drop # Dry Crush (lbs) ____ 8.9 2.3 '8 .4#/LTDC 9.2 2.6 1.6 The data show that NaOH provides some, but minimal binding action when employed alone.
Example 7 All previous testing employed only NaOH as a source of OH' ions. The present example investigates the use of other metal hydroxides for synergistic effect. The results are tabulated in Table 7.
Peridur 30~ Hydroxide Add'N Moisture Drop # Dry' Crush #/LTDC Source #/LTDC
(lbs) 1.0 KOH .45 10.0 5.4 2.8 1.0 NH,OH 1.46 10.0 6.4 3.3 1.0 Mg(OH)2 :45 9.9 4.3 1.9 1.0 ___ ___ 10.0 5.0 1.8 With the potassium hydroxide (KOH) and the ammonium hydroxide, (NHaOH) improvements, most noticeably in;the dry crush, were seen. This was not the case with the magnesium hydroxide Mg(OH)2, which appeared to deteriorate the surface~conditions 40 on the pellet, turning the green ball rough and wet.
WO 94/03648 ~ ~~ ~ ~ PCT/US92/06551 The results seen with the magnesium hydroxide'were not unexpected. It is known that any divalent canon will react with the CMC and cause a decrease in viscosity and/or ,performance. The NH4+ and K+ ions resulting from the other two hydroxides are monovalent cations and cause no adverse ' .M
effects.
While NaOH appears to outperform the other metal hydroxides, both KOH and NFi,OH seem to exhibit some synergism to the binding mechanism.
EXAMPLE g All previous examples employed only iron cre from a taconite source from northern Minnesota: Several other types of ore bodies'abound; most notably the specular.hematites in eastern Canada and'the magnetite ores i:n Sweden. Tests were run employing-a specular hematite ore from IOC and a magnetite ore from LKAB~ The results are tabulated in Table',8, below.
TABLE g ORE Peridur 300 NaOH Moisture Drop # ' Dry Crush #/LTDC #/LTDC
25' IOC 1.0 ___ g,8 g., 2.7 IOC 1.0'' .24 9.0 9.4 ' 4.0 LKAB 1.2 9:4' 5.0 ~ 4.8 .30 I~CAB 1.2'.24 9.5 7:2 ', 7.1 The data clearly show that other ore sources demonstrate the °3~5 same type'of synergism exhibited by the taconite are source.
The foregoing data clearly demonstrate the synergistic results of the present binder composition, which supports the patentability of the present invention.
Y~40' . ~ ~ ~~
The foregoing examples have been presented to demonstrate the surprising and unexpected superiority of the present invention in view of known technology, and said examples are .not intended to restrict the spirit and scope of the following claims.
The present invention generally relates to a process of agglomerating particulate materials, especially metal containing ores, in the presence of water. The process comprises mixing said particulate material with a binding effective amount of at least one polymer and a binder enhancing effective amount of caustic to produce a mixture, and thereafter or contemporaneously forming said mixture into agglomerates.
In the context of the present invention, the present inventors have found that the addition of caustic, in either liquid Or powdered form, to the mineral ore, as an integral 4a WO 94/03648 ~ ~ ~ R ~ PCT/US92/06551 part of the organic binder or as a separate entity, unexpectedly provides a synergistic effect in the pelletization process, giving the resultant pellets superior wet drop numbers and dry crush strength compared to pellets formed without the use of caustic. This increase in performance obtained by the addition of caustic allows the user to effectively reduce the amount of organic:binder required thus significantly reducing total binder cost.
The terra "agglomerated" or "agglomeration" as used in the contextof he present invention shall mean the'processing of finely divided materials, whether in powder, dus'~, chip, or other particulate form, to for:a pellets, granules, briquettes, and the like:
The particulate material which may be agglomerated in accordance with this present invention may be almost any finely divided material including metallic minerals or ore.
The predominant metal component in said ore may-, be iron, 2r0 chrome, copper, nickel, zinc, lead, uranium, borium and he dike. kiixtures of the above materials or any other metal occurring in the free or molecularly combined material state asa mineral, or any combination of the above, or other metals, or metal containing ores capable of pelletization, may 2'5- be agglomerated in accordance with the present invention. The present invention is particularly well adapted for the agglomeration of materials containing iron, including iron ore deposits, ore tailings,'cold and hot fines from a sinter process or aqueous iron'ore concentrates from natural sources 30 or recovered from various processes: Iron ore,or any of a wide variety of the'following minerals may for:a a part of the material to be agglomerated: taconite, magnetite, hematite, limonite, goethite, siderite, franklinite,, pyrite, chalcopyrite, chromite, ilmenite and the like.
Minerals other than-metallic minerals which may be agglomerated in accordance with the invention include r' WO 94/03648 ~ ~ ~ ~ ~ t PCTlUS92l06551 phosphate rock, talc, dolomite, limestone and the like. Still other materials which may be agglomerated in accordance with the present invention include fertilizer materials such as .potassium sulfate, potassium chloride, double sulfate of potassium and magnesium; magnesium-oxides animals feeds such ..
as calcium phosphates: carbon black: coal fines; catalyst mixtures; glass batch mixtures; borates, tungsten carbide;
refractory gunning mixes; antimony, flue dust from, for example, power generating plants, solid fuels such as coal, coke or charcoal, blast furnace fines and the like.
The water-soluble polymers) useful in the present invention include but are not limited to:
(1) Water-soluble natural polymers such as guar gum, starch, alginates, pectins, xanthan gum, dairy wastes, wood related products, lignin and the like;
(2), Modified natural polymers such as guar derivatives (e. g. hydroxypropyl guar, carboxymethyl guar, carboxymethylhydroxypropyl guar), modified starch (e. g.
anionic starch, cationic starch), starch derivatives (e. g.
dextrin) and cellulose derivatives such as alkali metal salts of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethylhydroxyethyl cellulose, methyl cellulose, lignin derivatives (e. g. carboxymethyl lignin) and the like; and/or (3) Synthetic polymers (e.g. polyacrylamides such as partially hydrated polyacrylamides; polyacrylates and copolymers thereof; polyethylene oxides, and the like).
The foregoing polymers may be used alone or in various combinations of two or more polymers. Water-soluble anionic polymers are a preferred class of polymers to be employed in the present invention.
Preferred polymers for use in the present invention are alkali metal salts of carboxymethyl cellulose. Any substantially water-soluble alkali metal salt of carboxymethyl cellulose may be used in this invention. The sodium salt is, however, preferred. Alkali metal salts of carboxymethyl cellulose, more particularly sodium carboxymethyl cellulose, are generally prepared from alkali cellulose and the respective alkali metal salt of monochloroacetic acid.
Cellulose which is used in the manufacture of sodium ,.
carboxymethyl cellulose is generally derived from wood pulp or cotton linters, but may be derived from other sources such as sugar beet pulp, bagasse, rice hulls, bran, microbially-derived cellulose, and waste.cellulose e.g. shredded paper).
The sodium carboxymethyl cellulose used in the present :invention generally has a degree of substitution ',(the average number of carboxymethyl ether groups per repeating anhydroglucose chain unit of the cellulose molecule) of from about 0.4 to about 1.5, more preferably about 0.6, to about 0.9, and most preferably about 0.7: Generally the average degree of polymerization of,the cellulose furnish is from about 50 to about 4000: Polymers having a degree of polymerization on the higher end of the, range are preferred.
It is more preferred to use sodium carboxymethyl'cellulose having a Brookfield.viscosity in a 1% aqueous solution of more than'2000 cps at:30 rpm, spindle #4. Still more preferred is sodium carboxy~nethyl cellulose having a 8rookfield viscosity in a i% aqueous solution of more than about 4,004 cps at 30 rpm spindle #4.
A series of commercially available binders containing sodium carboxymethyl cellulose especially useful in the present nvention is marketed by the Dreeland, Inc. of Virginia, lit, Denver;, CO, and Akzo Chemicals ofnAmersfoort, the Netherlands,; under the trademark Peridu~.
The "binding effective amount of polymer" will vary depending upon numerous factors known to 'the skilled artisan.
Such factors include, but are not limited to, the type of ~5 particulate material to be agglomerated or pelletized, the moisture'content of the particulate material, particle size, the agglomeration equipment utilized, and the desired WO 94/03648 ~ ~ ~ ~~ PCT/US92/06551 properties of the final product, e.g. dry strength (crush , drop number, pellet size and smoothness. Though not limiting, a binding effective amount of polymer will typically be in the range of between about 0.01% to 1% by weight based on the dry weight of the mixture of particulate material, polymer and ' caustic. Preferably, the polymer is present in a range of between about 0.01 to 0.4% by weight, and most preferred, about 0.04%.
As used herein, the term "caustic" shall mean any source of hydroxide ions (OH-) including, but not limited to sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, mixtures thereof and the like. Sodium hydroxide, commonly known as caustic soda, is the most preferred caustic.
A "binder enhancing effective amount of caustic" depends on.the same factors as does the binding effective amount of polymer. Without wishing to be bound to any particular ZO limitation, a binding effective amount of caustic will typically be in the range of between about .004% to .15% by weight based on the dry mixture of particulate material, polymer and caustic. Preferably, caustic ~is present in the range of between about .O1% to .04% by weight, and most preferred at about .03% by weight.
In another embodiment, the present invention contemplates a process of agglomerating particulate material in the presence of water which comprises mixing said particulate material with between about 0.01% to 1% by weight of at least one water soluble polymer selected from hydroxyethyl cellulose, alkali metal salts of carboxymethyl cellulose, methyl cellulose, methylhydroxyethyl cellulose and mixtures thereof, and .004% to .15% by weight of sodium hydroxide to produce a mixture, and forming said mixture into agglomerates.
WO 94/03648 2 ~ ~ ~ R ~ PGTlUS9Z/06551 In still another embodiment, the present invention contemplates a process of agglomerating iron ore wherein said ore is mixed with between about 0.01 to 0.4% by weight of an alkali metal salt of carboxymethyl cellulose, from about 0.01 to .04% by weight sodium hydroxide, and from about 0.02-0.5 wt% (based on dry ore) of soda ash, to produce a mixture, and forming said mixture into agglomerates.
Agglomerated particulate materials formed from any of the l0 foregoing processes is also deemed to be within the scope of the present invention.
The present invention also contemplates a binder composition useful for the agglomeration of particulate materials. The binder composition comprises a binding effective amount of at least one water soluble polymer, and a binder enhancing effective amount of caustic.
In a preferred embodiment, the present invention contemplates a binder composition which comprises between about 10% to 95% by weight of a water soluble polymer and between about 2% to 50% by weight of caustic (wt% binder composition).
In another preferred embodiment, the present invention contemplates a binder composition useful for the agglomeration of iron ore in the presence of water which comprises between about 45% to 95% by weight of a water-soluble alkali metal salt of carboxymethyl cellulose and l0% to 40% by weight of sodium hydroxide.
In yet another embodiment, the present invention contemplates a binder composition whichcomprises between about 50% to 80% by weight of an alkali metal salt of carboxymethyl cellulose, between about 10% to 35% by weight of caustic, and between about 2% to 20% bx weight of a salt of a weak acid, such as sodium citrate and or soda ash.
WO 94/03648 ~~ ' PCT/US92/06551 The binder composition of the present invention may also contain other substances, for instance, those that are formed as by-products in the preparation of the alkali metal salt of carboxymethyl cellulose, such as sodium chloride and sodium glycolate, as well as other polysaccharides or synthetic ", water-soluble polymers and other "inorganic salts" (for want of a better term sodium carbonate, sodium citrate, and the Like are referred to as "inorganic salts" herein). Exemplary polysaccharides include,'e:g., hydroxyethyl cellulose,.
hydroxypropyl cellulose, carboxymethylhydroxyethyl cellulose , methyl'cellulose, hydroxypropyl methyl cellulose, guar, hydroxpropyl guar and sugar. beet pulp, and the like.
Exemplary synthetic water-soluble polymers include partially hydrated polyacrylamide, polyvinyl alcohol, styrene/maleic anhydride copolymers, and polyacrylate and copolymers thereof, etc. Exemplary inorganic salts include; e. g. the salts described by Roorda in U. S. Patent Nos.4,288,245 and 4,597,797 such as sodium citrate, soda ash, and'the like.
The ratiosof polymer, e.g. alkali metal salt of carboxymethyl cellulose, caustic and water to particulate material, e.g.:concentrated ore are'dependent on various factors including the agglomeration method used, the material to be agglomerated.and th,e desired properties of the agglomerates to be prepared: A,person of ordinary skill in the art can readily detenaine the specific amounts that will be most suitable for individual circumstances.: Pelletization is generally carried out using;the binder comp4sition in an amount of from about 0.0044% to about 0.44%, preferably from about '0.022% to about 0.22% (by weight of the total dry mixture), of the binder composition and about 2% to about 20%, preferably about 5% to about 15%, water, by weight of the total dry mixture. In addition to the binder composition, clays'such as bentonite clay may be used in pelletization.
The total amount of these clays will depend on the user's objectives, but will generally be less than 0.22%, based on the weight of the total dry mixture:
WO 94/03648 2 ~ ~ 1 ~ ~ ~'~ PGT/US92/06551 Any known method for forming dry pellets or particles can be used to prepare the agglomerates of this invention. For instance, the concentrated ore may be agglomerated into particles or agglomerates by rotating the concentrated ore powder in a drum or disc with a binder and water, followed by drying and firing. Agglomerates can also be formed by '~
briquetting, nodulizing, or spray drying.
Addition of the binder composition constituents may be carried out in any manner commonly applied in the art. For' instance, the binder constituents may be mixed as solid matter with the concentrated ore in a dry or liquid form or as an emulsion or dispersion. Further, they may be simultaneously, successively or alternatively added to the concentrated ore before or during the pelletizing treatment. In a preferred method, Ziquid caustic is sprayed on moist concentrated ore resulting from the aforementioned separation process, which has all but about 10 wt% of the water removed by, e.g.
rotating disc filter. At a sufficient,point upstream from the agglomerating drum or disc, the polymeric binder composition is applied so that the binder components and concentrated ore are well mixed aad adequately hydrated prior to being formed w into green pellets. As non-limiting ranges, the water content should generally be in the range of about 4 to 30 wt% based on the weight of dry particulate matter and most preferably between about 7 and 12 wt%.
Other substances may also be optionally added to the binder composition of the present invention. For example, in iron ore pelletizing operations, small amounts of flux, e. g., limestone or dolomite may also be added to enhance mechanical properties of the pellets. The flux also helps to reduce the dust level in the indurating furnace when the pellets are fired. Olivine, serpentine, magnesium and similar minerals may be used to improve metallurgical properties of the pellets.
WO 94/03648 2, ~. ~ ~~ ~ PCT/US92/06551 Drying the wet balls and. firing the resultant dry balls may be carried out as one continuous or two separate steps.
The important factors are that the balls must be dry prior to ' firing as the balls will degrade or spall if fired without first drying them. It is therefore preferred that the balls ."
be heated slowly to a temperature of. at least about 2200'F, preferably to at least about 2400°F and then fired at that temperature. In another embodiment, they are dried at low temperatures, preferably by heating, or alternatively, under ambient conditions, and then fired at a temperature of at least about 2200'F, more preferably at about 2400'F. Firing is carried out for a sufficient period of time to bond the small particles-into-pellets with enough strength, to enable transportation and/or further handling, generally'about 15 minutes to about 3 hours.' The, process of the present invention; is preferably employed with concentrated iron ore. This process' is also suitablefor non-ferrous concentrated ores such a's ores of zinc, lead, tin, nickel and chromium and oxidic materials such as silicates and quartz, and sulphidicmaterials.' As a practical matter, this .invention is intended foruse in binding the concentrated ores which result-from separation of the host rock from the ore removed from the ground. However, it can also be used to bind natural ores.
The pellets resulting from this'process are dry, hard agglomerates having sizes-that are suitable for,''e. g.
shipping, handling, sintering,-etc. Pellets generally have 30. an average diameter of about i/4 to about l inch, preferably about 1/2 inch. Pellet size~is generally a function of the user and operator's preference, more than of binding ability of the compositions of this invention and~virtually any size pellet desired by blast furnace operations and mine operations :35: can be prepared:
The invention is further described by the following non-limiting examples. For the purpose of characterizing the agglomerates formed, use is made of the following procedure and test protocol.
..
AGGLOMERATE FORMATION
The process was begun by placing 2500 grams (calculated as dry weight) of iron ore concentrate (moisture content approximately 9 to 10 wt. %) into a Mullen Mixer (Model No. 1 Cincinnati Muller, manufactured by National Engineering Co.).
Caustic was thereafter evenly sprayed on the iron ore in liquid form, diluted from either a 10 Normal solution or sodium hydroxide pellets (97~%), both purchased from Fisher Scientific. The addition rate of the diluted caustic was carefully monitored and represented in the examFles as pounds dry caustic added per long ton dry concentrate (#/LTDC).
After caustic addition, polymer is then added to the mixer and spread evenly over the iron ore concentrate. If a mixture of polymers was used, the mixture was premixed by hand prior to addition to the muller mixer. The loaded mixer was run for three (3) minutes to evenly distribute the polymer.
The resulting concentrate mixture was screened to remove particles smaller than those retained on an 8 mesh wire screen.
A balling disc fabricated from an airplane tire (approx.
16" diameter) driven by a motor having a 60 RPM rotational speed was employed to produce green balls of the concentrate mixture. Pellet "seeds" were formed by placing a small portion of the screened concentrate mixture in the rotating balling tire and adding atomized water to initiate seed growth. As the size of the seed pellets..approached 4 mesh, they were removed from the balling disc and screened. The seed pellets with a size between 4 and 6 mesh were retained.
This process was repeated if necessary until 34 grams of seed pellets were collected.
WO 94/03648 2, ~~" ~ ~~ ~ ~ PCf/US92/06551 Finished green balls were;produced by placing the 34 grams of seed pellets of size between 4 and 6 mesh into the rotating tire of the balling disc and adding portion of the .remaining concentrate mixture from the muller mixer over a 4 minute growth period. Atomized water was added if necessary.
M
When the proper size was achieved (-0.530 inch, +0.500 inch) concentrate mixture addition ceased and the pellets were allowed a 30 second finishing roll. The agglomerated pellets were removed from the disc, screened to -0.530, +0.500 inch size and stored in an air-tight container until they were tested.
Test Protocol Wet DroQ Number was determined by repeatedly dropping two groups of ten (l0) pellets each from an 18 inch height to a steel plate until a crack appeared on the surface of each pellet. The number of drops xequired to produce a crack on the surface of each pellet was recorded. The average of all pellets was taken to determine the drop number of each 20 agglomerated mixture.
Crush Strength was determined by drying twenty (20) pellets of each agglomerated mixture to measure the moisture content. The dry pellets were then individually subjected to a Chatillon Spring Compression Tester, Model LTCM,(25 pound range) at a loading rate of O.l inch/second. The dry strength report for each agglomerate mixture is the average cracking pressure of the twenty pellets.
The following samples demonstrate processes and the binders of the present invention employing various polymers with sodium hydroxide and other OH', as binding agents for particulate material, which is iron ore unless otherwise specified.
WO 94/03648 ~ "~ ~ ! ~'~ ~ *~ PCT/US92/06551 .
Example 1 In this example,a pure sodium carboxymethyl cellulose (CMC) polyme r binderwas employed (Peridu~30oZ)with and without the additionof caustic. Table l, below clearly shows that the per formanceof the pure CMC binder tremendously is improved by the addition ic.
of caust PURE CMC NaOH Moisture Wet Drop Dry Crush #/LTDC #/LTDC ( ~s ) 1.0 ___ 9.9 8.2 5.3 1.0 .12 10.3 10.5 7.7 1.0 .24 10.1 11.1 10.6 1.0 1.2 10.0 9.5 '11.9 1.0 2.4 9.7 7.3 8.8 1.0 4.0 9.2 5.6 8.0 # = Pounds LTDC = Long ton dry concentrate The data of Table l clearly show that the perfonaance of pure CMC is greatly enhanced by the addition of NaOH. Tn this case, there is an optimum level of NaOH addition at between about .24 to l.2 #/LTDC. When excessive amounts of caustic are added, the wet drops start to decrease, probably from binder deterioration at higher pH levels.
example 2 A technical grade up to out 25% salt CMC containing ab byproducts (Peridur 200~)was also tested and without the with addition of caustic. Table 2, below, contains the data.
Technical Grade CMC NaOH Moisture Wet Drops Dry Crush #/LTDC #LTDC C ~s ) ~
,g0 ___ 10.2 6.6 1.7 .90 .12 10:5 7.9 2.1 .90 .24 10.4 8.5 3.2 .90 1.2 10.1 8.9 7.5 .90 2.4 10.1 8.4 7.2 WO 94!03648 ~ ~ ~ ~ ~ ~ ~ PCT/US92/06551 '-The data clearly shows that the addition of caustic greatly improves the performance of the technical grade CMC. Like the pure grade CMC of Example 1, there is an optimum level of caustic addition wherein product performance peaks, and thereafter slowly deteriorates beyond optimum addition levels.
Examt~le 3 A CMC/soda ash combination was employed with and without the addition of NaOH. The CMC/soda ash combination consists of about 70 to 85% technical grade CMC and 15-30% soda ash.
The data obtained is compiled in Table 3, below.
Technical Grade CMC/Soda Ash Add'n NaOH Moisture Drop # Dry Crush #/LTDC #/LTDC
(lbs) Peridu~ 2.15 1.06 --- 10.0 7.1 3.7 2.15 ~ 1.06 .12 10.0 7.5 5.0 2.15 1.06 .24 10.2 9.0 5.8 2.15 1.06. 1.2 10.0 8.2 7.8 2.15 1.06 2.4 9.9 7.0 7.4 Peridu~3.15 1.0 --- 9.5 4.6 2.2 3.15 1.0 .24 9.7 5.4 5.2 3.15 1.2 --- 9.5 5.0 3.0 3.15 1.2 .24 9.? 6.4 7.2 Periduz~3.30 1.0 --- 9.4 4.3 2.7 3.30 1.0 .24 9.6 4.7 5.2 3.30 1.2 -- 9.2 4.5 4.2 3.30 1.2 .24 9.6 6.1 6.7 *Periduz~ 2.15, Peridu~3.15 and Peridu~3.30 are binder 40. compositions commercially available from Dreeland, Inc., Virginia, MN, Denver CO, and Akzo Chemicals, Amersfoort, the Netherlands.
The data clearly show that in every instance of caustic addition, there was an improvement in the pellet quality as compared to the pellets formed with no caustic addition.
WO 94/03548 ~ ~ ~ ~ ~ ~ PCT/US92/06551 Example 4 In this trial, applicants tested a series of anionic polymers, including polymers of polyacrylamide (PL1400~).
POLYACRYLATE (FP 1000 , CM GUAR carboxymethyldihydroxypropyl cellulose (CMDHPC), carboxymethylhydroxyethyl cellulose M
(CMHEC); and, Stabilos~ LV, a carboxymethyl starch (CM
Starch) with and without caustic addition. The data is tabulated in Table 4 below.
Product Add'n NaOH Moisture Drop # Dry Crush #/LTDC #/LTDC
(lbs) PAM (PL 1.1 --- 14.8 5.5 1.6 1400)~
PAM (PL 1.1 .24 11.3 6.9 1.9 1400) PAM (PL 1.1 1.2 11.0 7.2 3.4 1400) PAA (FP 1.0 ._- 9.1 2.9 2.5 10f~) PAA (FP 1:0 1.2 9.3 2.9 5.3 100) CM-GUAR 1.0 --- 20.0 7.0 1.7 CM-GUAR 1.0 .12 10.2 8.8 2.3 CM-GUAR 1.0 .24 10:1 6.9 2.?
CM=GUAR 1.0 .43 9.9 7.7 3.1 CM-GUAR 1.0 .72 9.9 3.2 2.3 CM-GUAR 1.0 1.2 9.4 2.3 2.0 CMDHPC 1.0 --- 8.9 2.7 1.3 CMDHPC 1.0 .24 9.1 2.6 1.7 , CMHEC 1.0 --_ 9.2 3.6 1.4 CMHEC 1.0 .24 9.6 4.2 2.4 SEC 1.0 1.2 9:5 3.5 3.6 CM-Starch 2.0 --- 9.7 3.3 3.3 CM-Starch 2.0 .48 9.8 4.3 7.1 * PL1400'~ polyacrylamide commercially available from is a Stockhaus en, Inc.
* FP100~ polyacrylate is a commercially available from Polyacryl Inc.
* HP-8 s produced sold Hi-Tek Polymers.
i and by * Guar available 5200 is through Economy Mud Products.
The polyacrylamide the polyacrylate (PL1400s), (FP100e), 5p CMDHPC, and CM- Starch showed benefits CNgiPC, throughout the WO 94/03648 ~ ~~~ ~'~ PCT/US92/06551, addition of caustic. This was not the case with the CM-Guar.
Small additions of caustic significantly improved performance, however when the dosage of caustic increased was beyond optimum levels, both the wet and dry trengths weredestroyed.
s w Example 5 Non-ionic polymers have also beenconsidered for use a binders: These pollrmers incl ude, but are not limited to hydroxyethyl cellulose (HEC), methyl hydroxyethyl cellulose (Meth. HEC), hydroxypropyl ce llulose HPC), starch,dextrin, ( guar (guar 5200), and hydroxypropyl' stic guar (HPG). Cau addition to these binders was also investigated, the data and is tabulated in Table 5, below.
,15 TABLE 5 Polymer Add'n NaOH Moi ture Drop # Dry Crush #/LTDC #/LTDC (lbs) HEC / T.0 96 7.7 2.9 HEC 1.0' .24 9.9 11.1 3.4 HEC 1.0 1.2 10,1 10.7 3.6 Meth.HEC 1.0 g7 5:9 4:3 Meth.HEC 1.0 .24 9.9 7.0 4:6 25, 4 HPC 1.0 9:9 6.1 2E
HPC 1.0 .24 10:9 6.7 3.0 Starch 4:0 9.8 4.1 5.8 3 0 Starch 40 .24. 101 4.7 5.7 Dextrin 4.0 8.5 2.5 4:9 Dextrin 4.0 :24 g2 2.8 4.8 35 Guar 5200 1.0 10.7 4:6 1.8 Guar 5200 1.0 .24' 9:7 3.8 1.4 HPG (IiP8 ) 1. 0 --_- 113 7 . 7 2 , p HPG (HP8) 1:0 .24 95 2:7 ' 1,5 The data clearly demonstrate that the cellulos3cs all showed some improvement, albeit the improvements as great as were,not .fir ~~ 4:5 those seen with anionic binders:
The starch and dextrin binders tested showed no improvement in wet drop numbers and dry strengths.
Example 6 To determine whether or not caustic itself may be contributing to the dry strength of pellets by forming its own binder bridges, iron ore was pelletized using only caustic.
The data is compiled in Table 6 below.
NaOH Add'n Moisture Drop # Dry Crush (lbs) ____ 8.9 2.3 '8 .4#/LTDC 9.2 2.6 1.6 The data show that NaOH provides some, but minimal binding action when employed alone.
Example 7 All previous testing employed only NaOH as a source of OH' ions. The present example investigates the use of other metal hydroxides for synergistic effect. The results are tabulated in Table 7.
Peridur 30~ Hydroxide Add'N Moisture Drop # Dry' Crush #/LTDC Source #/LTDC
(lbs) 1.0 KOH .45 10.0 5.4 2.8 1.0 NH,OH 1.46 10.0 6.4 3.3 1.0 Mg(OH)2 :45 9.9 4.3 1.9 1.0 ___ ___ 10.0 5.0 1.8 With the potassium hydroxide (KOH) and the ammonium hydroxide, (NHaOH) improvements, most noticeably in;the dry crush, were seen. This was not the case with the magnesium hydroxide Mg(OH)2, which appeared to deteriorate the surface~conditions 40 on the pellet, turning the green ball rough and wet.
WO 94/03648 ~ ~~ ~ ~ PCT/US92/06551 The results seen with the magnesium hydroxide'were not unexpected. It is known that any divalent canon will react with the CMC and cause a decrease in viscosity and/or ,performance. The NH4+ and K+ ions resulting from the other two hydroxides are monovalent cations and cause no adverse ' .M
effects.
While NaOH appears to outperform the other metal hydroxides, both KOH and NFi,OH seem to exhibit some synergism to the binding mechanism.
EXAMPLE g All previous examples employed only iron cre from a taconite source from northern Minnesota: Several other types of ore bodies'abound; most notably the specular.hematites in eastern Canada and'the magnetite ores i:n Sweden. Tests were run employing-a specular hematite ore from IOC and a magnetite ore from LKAB~ The results are tabulated in Table',8, below.
TABLE g ORE Peridur 300 NaOH Moisture Drop # ' Dry Crush #/LTDC #/LTDC
25' IOC 1.0 ___ g,8 g., 2.7 IOC 1.0'' .24 9.0 9.4 ' 4.0 LKAB 1.2 9:4' 5.0 ~ 4.8 .30 I~CAB 1.2'.24 9.5 7:2 ', 7.1 The data clearly show that other ore sources demonstrate the °3~5 same type'of synergism exhibited by the taconite are source.
The foregoing data clearly demonstrate the synergistic results of the present binder composition, which supports the patentability of the present invention.
Y~40' . ~ ~ ~~
The foregoing examples have been presented to demonstrate the surprising and unexpected superiority of the present invention in view of known technology, and said examples are .not intended to restrict the spirit and scope of the following claims.
Claims (57)
1. A process for agglomerating particulate material comprising:
(a) pretreating said particulate material with a binder enhancing effective amount of a liquid spray of a source of hydroxide ions;
(b) mixing said pretreated particulate material with a binding effective amount of a water-soluble polymer and water; and (c) forming said mixture into agglomerates.
(a) pretreating said particulate material with a binder enhancing effective amount of a liquid spray of a source of hydroxide ions;
(b) mixing said pretreated particulate material with a binding effective amount of a water-soluble polymer and water; and (c) forming said mixture into agglomerates.
2. The process of claim 1, wherein said water-soluble polymer is guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, carboxymethylhydroxypropyl guar, modified starch, starch derivatives, carboxymethyl starch, pregelatinized starch, alginates, pectins, polyacrylamides and derivatives thereof, polyacrylates and copolymers thereof, polyethyleneoxides, cellulose derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, methylhydroxyethyl cellulose, carboxymethyldihydroxypropyl cellulose, xanthan gum, dairy wastes, wood related products, lignin, or mixtures thereof.
3. The process of claim 1, wherein said source of hydroxide ions is sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide or mixtures thereof.
9. The process of claim 1, wherein said particulate material is a metal-containing ore.
5. The process of claim 4, wherein said metal-containing ore is iron ore.
6. The process of claim 1, wherein said water-soluble polymer is an alkali metal salt of carboxymethyl cellulose and said source of hydroxide ions is sodium hydroxide.
7. The process of claim 1, wherein said binder enhancing effective amount of hydroxide ions is in a range of from about 0.004% to about 0.15% by weight, based on the dry mixture of particulate material, water-soluble polymer and source of hydroxide ions.
8. The process of claim 7, wherein said range is from about 0.01% to about 0.04%.
9. The process of claim 1, wherein said binding effective amount of water-soluble polymer is in a range of from about 0.01% to about 1% by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer and source of hydroxide ions.
10. The process of claim 9, wherein said range is from about 0.01% to about 0.4%.
11. The process of claim 9, wherein said particulate material contains about 10% by weight water.
12. The process of claim 1, wherein said water is present in an amount in a range of from about 4% to about 30%.
by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer, and hydroxide ions.
by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer, and hydroxide ions.
13. A process of agglomerating particulate material in the presence of water which comprises mixing said particulate material with a binding effective amount fro about 0.01% to about 1% by weight of at least one water soluble polymer, based on the weight of the dry mixture and a binder enhancing effective amount of about 0.01 to about 0.04% caustic, to produce a mixture, and forming said mixture into agglomerates.
14. The process of claim 13, wherein said water soluble polymer is selected from the group consisting of guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, carboxymethylhydroxypropyl guar, modified starch, starch derivatives, carboxymethyl starch, pregelatinized starch, alginates, pectins, polyacrylamides and derivatives thereof, polyacrylates and copolymers thereof, polyethylene oxides, cellulose derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, methylhydroxyethyl cellulose, carboxymethyldihydroxypropyl cellulose, xanthan gum, dairy wastes, wood related products, and mixtures thereof.
15. The process of claim 13, wherein said caustic is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide and mixtures thereof.
16. The process of claim 13, wherein said particulate material is iron ore.
17, A process of agglomerating iron ore in the presence of water which comprises mixing said iron ore with a binding effective amount of at least one water soluble polymer, and a binder enhancing effective amount of about 0.004% to about 0.15% by weight caustic, based on the weight of the dry mixture, to produce a mixture, and forming said mixture into agglomerates.
18. The process of claim 16, wherein said water-soluble polymer is an alkali metal salt of carboxymethyl cellulose and said caustic is sodium hydroxide.
19. The process of claim 18, wherein said water soluble polymer additionally comprises a salt of a weak acid selected from the group consisting of soda ash, sodium citrate, and mixtures thereof.
20. A process of agglomerating particulate material in the presence of water which comprises mixing said particulate material with between about 0.01% to 1% by weight of at least one water soluble polymer selected from the group consisting of hydroxyethyl cellulose, sodium carboxymethyl cellulose, methyl cellulose, methylhydroxyethyl cellulose, polyacrylate and copolymers thereof, polyacrylamide and derivatives thereof, modified starch, starch derivatives, carboxymethyl starch, guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, and mixtures thereof, and 0.004% to 0.15% by weight of sodium hydroxide to produce a mixture, and forming said mixture into agglomerates.
21. The process of claim 20, wherein said water soluble polymer is an alkali metal salt of carboxymethyl cellulose.
22. The process of claim 21, wherein said particulate material is iron ore.
23. A process of agglomerating iron ore in the presence of water which comprises mixing said iron ore with between about 0.01% to 1% by weight of at least on water soluble polymer selected from the group consisting of hydroxyethyl cellulose, alkali metal salts of carboxymethyl cellulose, methyl cellulose, methylhydroxyethyl cellulose, polyacrylate and copolymers thereof, polyacrylamide and derivatives thereof, modified starch, starch derivatives, carboxymethyl starch, guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, and mixtures thereof, and 0.004% to 0.15% by weight of sodium hydroxide to produce a mixture, and forming said mixture into agglomerates.
24. The process of claim 23, wherein said water soluble polymer additionally comprises a salt of a weak acid selected from the group consisting of soda ash, sodium citrate and mixtures thereof.
25. The process of claim 20, wherein said water soluble polymer is carboxymethyl guar.
26. The process of claim 20, wherein said water soluble polymer is carboxymethyl starch.
27. The process of claim 24, wherein said iron ore is mixed with between about 0.01 to 0.4% by weight of an alkali metal salt of carboxymethyl cellulose, from about 0.01 to 0.04% by weight sodium hydroxide, and from 0.02 to 0.5wt% soda ash, to produce a mixture, and forming said mixture into agglomerates.
28. A binder composition useful for the agglomeration of particulate material in the presence of water which comprises a binding effective amount of between about 10% to 95% by weight of a water-soluble polymer and a binder enhancing effective amount of between about 2%
to 50% by weight of caustic.
to 50% by weight of caustic.
29. The composition of claim 28, wherein said water soluble polymer is selected from the group consisting of guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, carboxymethylhydroxypropyl guar, modified starch, starch derivatives, carboxymethyl starch, pregelatinized starch, alginates, pectins, polyacrylamides and derivatives thereof, polyacrylates and copolymers thereof, polyethyleneoxides, cellulose derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, methylhydroxyethyl cellulose, carboxymethyldihydroxypropyl cellulose, xanthan gum, dairy wastes, wood related products, and mixtures thereof.
30. The composition of claim 28, wherein said caustic is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, and mixtures thereof.
31. The composition of claim 28, wherein said particulate material is iron ore.
32. A binder composition useful for the agglomeration of iron ore in the presence of water which comprises a binding effective amount of between about 10% to 95% by weight of a water-soluble polymer and a binder enhancing effective amount of between 2% to 50% by weight of caustic.
33. The composition of claim 32, wherein said water soluble polymer is an alkali metal salt of carboxymethyl cellulose and said caustic is sodium hydroxide.
34. A binder composition useful for the agglomeration of iron ore in the presence of water which comprises between about 45% to 96% by weight of sodium carboxymethyl cellulose and 10% to 40% by weight of sodium hydroxide.
35. A process of agglomerating particulate material in the presence of water which comprises mixing said particulate material with a binding effective amount of at least one water soluble polymer and a binder enhancing effective amount of about 0.004% to about 0.15% by weight caustic, based on the weight of the dry mixture, to produce a mixture, and forming said mixture into agglomerates.
36. The process of claim 35, wherein the binder enhancing effective amount of caustic is about 0.01% to about 0.04%.
37. The process of claim 13, wherein said water is present in an amount in a range of from about 4% to about 30%
by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer, and caustic.
by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer, and caustic.
38. The binder composition of claim 28, further comprising from about 2% to about 20% by weight of a salt of a weak acid.
39. The binder composition of claim 38, wherein said salt of a weak acid is soda ash, sodium citrate or mixtures thereof.
40. The binder composition of claim 39, further comprising from about 1 to 25% salt by products.
41. The process of claim 13, wherein the binding effective amount of water soluble polymer is from about 0.01% to about 0.4%.
42. The process of claim 17, wherein the binder enhancing effective amount of caustic is about 0.01% to about 0.04%.
43. The process of claim 17, wherein said binding effective amount of water-soluble polymer is in a range of from about 0.01% to about 1%, based on the weight of the dry mixture.
44. The process of claim 17, wherein said binding effective amount of water-soluble polymer is in a range of from about 0.01% to about 0.4%, based on the weight of the dry mixture.
45. The process of claim 17, wherein said water soluble polymer is selected from the group consisting of guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, carboxymethylhydroxypropyl guar, modified starch, starch derivatives, carboxymethyl starch, pregelatinized starch, alginates, pectins, polyacrylamides and derivatives thereof, polyacrylates and copolymers thereof, polyethyleneoxides, cellulose derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, methylhydroxyethyl cellulose, carboxymethyidihydroxypropyl cellulose, xanthan gum, dairy wastes, wood related products; and mixtures thereof.
46. The process of claim 17, wherein said caustic is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide and mixtures thereof.
47. The process of claim 17, wherein said water is present in an amount in a range of from about 4% to about 30%
by weight, based on the weight of the dry mixture of iron ore, water-soluble polymer, and caustic.
by weight, based on the weight of the dry mixture of iron ore, water-soluble polymer, and caustic.
48. The process of claim 17, wherein said water-soluble polymer is an alkali metal salt of carboxymethyl cellulose and said caustic is sodium hydroxide.
49. The process of claim 48, wherein said water soluble polymer additionally comprises a salt of a weak acid selected from the group consisting of soda ash, sodium citrate, and mixtures thereof.
50. The process of claim 35, wherein said water soluble polymer is selected from the group consisting of guar, guar derivatives, carboxymethyl guar, hydroxypropyl guar, carboxymethylhydroxypropyl guar, modified starch, starch derivatives, carboxymethyl starch, pregelatinized starch, alginates, pectins, polyacrylamides and derivatives thereof, polyacrylates and copolymers thereof, polyethyleneoxides, cellulose derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, methylhydroxyethyl cellulose, carboxymethyldihydroxypropyl cellulose, xanthan gum, dairy wastes, wood related products, and mixtures thereof.
51. The process of claim 35, wherein the binding effective amount of water soluble polymer is about 0.01% to about 1%.
52. The process of claim 35, wherein the binding effective amount of water soluble polymer is about 0.01% to about 0.4%.
53. The process of claim 35, wherein said caustic is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide and mixtures thereof.
54. The process of claim 35, wherein said water is present in an amount in a range of from about 4% to about 30%
by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer, and caustic.
by weight, based on the weight of the dry mixture of particulate material, water-soluble polymer, and caustic.
55. The process of claim 35, wherein said particulate material is iron ore.
56. The process of claim 35, wherein said water-soluble polymer is an alkali metal salt of carboxymethyl cellulose and said caustic is sodium hydroxide.
57. The process of claim 56, wherein said water soluble polymer additionally comprises a salt of a weak acid selected from the group consisting of soda ash, sodium citrate, and mixtures thereof.
Priority Applications (10)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU24067/92A AU685385B2 (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
| DE69230806T DE69230806T2 (en) | 1992-08-06 | 1992-08-06 | BINDER COMPOSITION AND METHOD FOR AGGLOMING PARTICULATE MATERIALS |
| ES92917701T ES2144422T3 (en) | 1992-08-06 | 1992-08-06 | BINDING COMPOSITION AND PROCEDURE FOR BONDING PARTICULAR MATERIAL. |
| BR9207150A BR9207150A (en) | 1992-08-06 | 1992-08-06 | Binder process and composition for agglomerating particulate material and iron ore in the presence of water |
| AT92917701T ATE190671T1 (en) | 1992-08-06 | 1992-08-06 | BINDER COMPOSITION AND METHOD FOR AGGLOMATE PARTICLE MATERIAL |
| EP92917701A EP0656072B1 (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
| US08/373,289 US5698007A (en) | 1992-08-06 | 1992-08-06 | Process for agglomerating particulate material |
| PCT/US1992/006551 WO1994003648A1 (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
| CA002141787A CA2141787C (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
| NO19950401A NO311227B1 (en) | 1992-08-06 | 1995-02-03 | Process for agglomeration of particulate material |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BR9207150A BR9207150A (en) | 1992-08-06 | 1992-08-06 | Binder process and composition for agglomerating particulate material and iron ore in the presence of water |
| PCT/US1992/006551 WO1994003648A1 (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
| CA002141787A CA2141787C (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2141787A1 CA2141787A1 (en) | 1994-02-17 |
| CA2141787C true CA2141787C (en) | 2006-10-10 |
Family
ID=27160068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002141787A Expired - Lifetime CA2141787C (en) | 1992-08-06 | 1992-08-06 | Binder composition and process for agglomerating particulate material |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0656072B1 (en) |
| AT (1) | ATE190671T1 (en) |
| AU (1) | AU685385B2 (en) |
| BR (1) | BR9207150A (en) |
| CA (1) | CA2141787C (en) |
| DE (1) | DE69230806T2 (en) |
| ES (1) | ES2144422T3 (en) |
| NO (1) | NO311227B1 (en) |
| WO (1) | WO1994003648A1 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1035481C (en) * | 1994-06-30 | 1997-07-23 | 潘金海 | Organic binder for metallurgy |
| CN1037516C (en) * | 1995-07-03 | 1998-02-25 | 潘金海 | Additive for metallurgy |
| CA2251339A1 (en) | 1997-10-30 | 1999-04-30 | Hidetoshi Tanaka | Method of producing iron oxide pellets |
| US20040221426A1 (en) | 1997-10-30 | 2004-11-11 | Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) | Method of producing iron oxide pellets |
| GB9724032D0 (en) * | 1997-11-13 | 1998-01-14 | Allied Colloids Ltd | Ore pelletisation |
| DE10027796A1 (en) * | 2000-06-07 | 2002-01-10 | Thyssen Krupp Metallurg Gmbh | Process for briquetting nickel oxide powder, as well as nickel oxide briquette |
| WO2012112773A1 (en) * | 2011-02-16 | 2012-08-23 | Solix Biosystems, Inc. | Compositions and methods for leach extraction of microorganisms |
| DE102013114339A1 (en) * | 2013-12-18 | 2015-06-18 | Outotec (Finland) Oy | Process for pelletizing fine-grained ores |
| RU2590034C1 (en) * | 2015-01-12 | 2016-07-10 | Общество с ограниченной ответственностью "Научно-производственное внедренческое предприятие ТОРЭКС" | Method of intensifying processes of agglomeration of iron ore materials |
| IT201800006815A1 (en) * | 2018-06-29 | 2019-12-29 | AN ORGANIC-INORGANIC HYBRID MATERIAL COMPRISING A METAL AND LIGNIN, PROCESSES FOR PREPARING THE SAME AND USES THEREOF / HYBRID ORGANIC-INORGANIC MATERIAL INCLUDING METAL AND LIGNIN, PROCESSES FOR ITS PREPARATION AND USES | |
| CN109112297B (en) * | 2018-10-19 | 2020-08-28 | 攀钢集团攀枝花钢铁研究院有限公司 | Binder for forming converter enriched sludge and converter enriched sludge forming method |
| KR20220134012A (en) * | 2020-05-18 | 2022-10-05 | 닛폰세이테츠 가부시키가이샤 | Method for producing a condensed material and a condensed material |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US825440A (en) * | 1905-08-10 | 1906-07-10 | Wesley G Woodmansee | Ironing-table. |
| US2914394A (en) * | 1956-04-05 | 1959-11-24 | Dohmen Heinrich | Briquetting of ores |
| US2862809A (en) * | 1956-08-14 | 1958-12-02 | Olin Mathieson | Soda ash briquette and its method of manufacture |
| US3644113A (en) * | 1968-09-04 | 1972-02-22 | Int Minerals & Chem Corp | Agglomerate including graft copolymers of acylic acid and methyl cellulose and method of making |
| US3852059A (en) * | 1972-03-09 | 1974-12-03 | Allied Chem | Process for the production of sodium chromate from chromite ore |
| NL187123C (en) * | 1975-11-20 | 1991-06-03 | Akzo Nv | METHOD FOR AGGLOMERATING ORE MATERIALS |
| MC1284A1 (en) * | 1979-06-11 | 1980-07-22 | Daussan & Co | GRANULAR INSULATING PRODUCT AND ITS PREPARATION METHOD |
| US4863512A (en) * | 1987-06-29 | 1989-09-05 | Aqualon Company | Binder for metal-containing ores |
| US4751259A (en) * | 1987-08-05 | 1988-06-14 | Nalco Chemical Company | Compositions for iron ore agglomeration |
| GB8830383D0 (en) * | 1988-12-30 | 1989-03-01 | Allied Colloids Ltd | Process and composition for pelletising particulate materials |
| US5112582A (en) * | 1990-04-09 | 1992-05-12 | Betz Laboratories, Inc. | Agglomerating agents for clay containing ores |
| US4948430A (en) * | 1989-06-15 | 1990-08-14 | Aqualon Company | Ore pellets containing carboxymethylhydroxyethylcellulose and sodium carbonate |
| FR2654012B1 (en) * | 1989-11-06 | 1994-02-11 | Roquette Freres | BINDING AGENT AND BINDING COMPOSITION FOR THE AGGLOMERATION OF FINELY DIVIDED MATERIALS, AGGLOMERATES THUS OBTAINED AND PROCESS FOR PREPARING THE SAME. |
| US5112391A (en) * | 1990-03-30 | 1992-05-12 | Nalco Chemical Company | Method of forming ore pellets with superabsorbent polymer |
| CA2069482C (en) * | 1990-09-26 | 2004-06-01 | David L. Dingeman | Modified native starch base binder for pelletizing mineral material |
| CA2082128C (en) * | 1991-11-07 | 2002-12-31 | Henricus R. G. Steeghs | Process for agglomerating particulate material and products made from such processes |
-
1992
- 1992-08-06 EP EP92917701A patent/EP0656072B1/en not_active Expired - Lifetime
- 1992-08-06 AT AT92917701T patent/ATE190671T1/en not_active IP Right Cessation
- 1992-08-06 BR BR9207150A patent/BR9207150A/en not_active IP Right Cessation
- 1992-08-06 DE DE69230806T patent/DE69230806T2/en not_active Expired - Fee Related
- 1992-08-06 CA CA002141787A patent/CA2141787C/en not_active Expired - Lifetime
- 1992-08-06 AU AU24067/92A patent/AU685385B2/en not_active Ceased
- 1992-08-06 ES ES92917701T patent/ES2144422T3/en not_active Expired - Lifetime
- 1992-08-06 WO PCT/US1992/006551 patent/WO1994003648A1/en active IP Right Grant
-
1995
- 1995-02-03 NO NO19950401A patent/NO311227B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| AU685385B2 (en) | 1998-01-22 |
| AU2406792A (en) | 1994-03-03 |
| EP0656072A4 (en) | 1996-06-26 |
| NO950401D0 (en) | 1995-02-03 |
| ES2144422T3 (en) | 2000-06-16 |
| NO311227B1 (en) | 2001-10-29 |
| CA2141787A1 (en) | 1994-02-17 |
| ATE190671T1 (en) | 2000-04-15 |
| NO950401L (en) | 1995-02-03 |
| DE69230806T2 (en) | 2000-11-16 |
| DE69230806D1 (en) | 2000-04-20 |
| WO1994003648A1 (en) | 1994-02-17 |
| BR9207150A (en) | 1995-12-12 |
| EP0656072B1 (en) | 2000-03-15 |
| EP0656072A1 (en) | 1995-06-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed | ||
| MKEC | Expiry (correction) |
Effective date: 20121202 |