Pelletized products and processes for making same

Abstract

Pelletized products and processes for making same. In some embodiments, the pelletized product can include a plurality of ore particles and a binder. The binder can include bentonite and at least one of a cationic polyacrylamide copolymer and an anionic acrylamide sodium acrylate copolymer. The cationic polyacrylamide copolymer, if present, can include polymer units derived from four monomers. The anionic acrylamide-sodium acrylate copolymer, if present, can be in the form of a mixture comprising the anionic acrylamide sodium acrylate copolymer, water, and hydrotreated light petroleum distillates.

Description

DOCKET No.: N12179WO01 PATENTPELLETIZED PRODUCTS AND PROCESSES FOR MAKING SAMEFIELD

[0001] Embodiments described generally relate to pelletized products and processes for making same. More particularly, such embodiments relate to pelletized products that include a plurality of ore particles and a binder that includes bentonite and at least one of a cationic polyacrylamide copolymer and an anionic acrylamide-sodium acrylate copolymer and processes for making same.BACKGROUND

[0002] Green pellets are made by mixing ore fines, e.g., iron ore, with a binder and rolling the mixture into balls using a pelletizing disk or a pelletizing drum. The formed green pellets can then be heated in an indurating furnace to produce a plurality of fired pellets. Over the years, pellet production has become increasingly more prevalent with the increased exploitation of lower-grade ores, e.g., lower-grade iron ores.

[0003] A common and typical binder used to make iron ore pellets is bentonite because the bentonite produces green pellets that exhibit good wet and dry strength properties, and the bentonite provides good moisture control in the green pellets. Bentonite, however, contains a significant amount of silicate and depending on the particular source can include upwards of about 50 wt% to about 65 wt% of silicate, which leads to an increased rate of coke formation in the blast furnace when the fired pellets are melted for processing the ore into end products.

[0004] There is a need, therefore, for improved binders, pelletized products made therewith, and processes for making same.SUMMARY

[0005] Pelletized products and processes for making same are provided. In some embodiments, the pelletized product can include a plurality of ore particles and a binder. The binder can include bentonite and at least one of a cationic polyacrylamide copolymer and an anionic acrylamide-sodium acrylate copolymer. The cationic polyacrylamide copolymer, if present, can include polymer units derived from four monomers. The anionic acrylamide-sodium acrylate copolymer, if present, can be in the form of a mixture that can include the anionic acrylamide-sodium acrylate copolymer, water, and hydrotreated light petroleum distillates.

[0006] In some embodiments, a process for pelletizing particles can include mixing a plurality of ore particles with a binder to produce a mixture. The binder can include bentonite and atDOCKET No.: N12179WO01 PATENTleast one of a cationic polyacrylamide copolymer and an anionic acrylamide-sodium acrylate copolymer. The cationic polyacrylamide copolymer, if present, can include polymer units derived from four monomers. The anionic acrylamide-sodium acrylate copolymer, if present, can be in the form of a mixture that can include the anionic acrylamide-sodium acrylate copolymer, water, and hydrotreated light petroleum distillates. The process can also include pelletizing the mixture to produce a pelletized product.DETAILED DESCRIPTION

[0007] In some embodiments, a pelletized product can include a plurality of ore particles and a binder that can include, but is not limited to, bentonite and at least one of a cationic polyacrylamide copolymer and an anionic acrylamide-sodium acrylate copolymer. The binder can be used to agglomerate the plurality of ore particles to form an agglomerated or pelletized product. The cationic polyacrylamide copolymer can include polymer units derived from four monomers. The anionic acrylamide-sodium acrylate copolymer can be in the form of a mixture that includes the anionic acrylamide-sodium acrylate polymer, hydrotreated light petroleum distillates, and water.

[0008] It has been discovered that the cationic polyacrylamide copolymer and / or the anionic acrylamide-sodium acrylate copolymer can be used to replace a portion of the bentonite in the binder to make the pelletized product that includes the binder and the plurality of ore particles. Replacing a portion of the bentonite with the cationic polyacrylamide copolymer and / or the anionic acrylamide-sodium acrylate copolymer can provide a pelletized product having improved properties as compared to the binder that only includes the bentonite and neither of the copolymers. For example, as shown in the examples below, using just the cationic polyacrylamide copolymer can allow the amount of bentonite in the binder to be reduced by about 27% while providing an increase of about 14.7% in the cold crushing strength of the as formed pellets. In another example, as shown in the examples below, the combination of both the cationic polyacrylamide copolymer and the anionic acrylamide-sodium acrylate copolymer can allow the amount of bentonite in the binder to be reduced by about 35% while providing an increase of about 28% in the cold crushing strength of the as formed pellets.

[0009] In some embodiments, the ore particles can be or can include, but are not limited to, iron-bearing ores, gold-bearing ores, silver-bearing ores, copper-bearing ores, nickel-bearing ores, zinc -bearing ores, lead-bearing ores, uranium-bearing ores, barium-bearing ores, niobium-bearing ores, rutile, cassiterite, pyrite, franklinite, chalcopyrite, chromite, ilmenite, or a mixture thereof. In some embodiments, the iron-bearing ore can be or can include, but is not limited to, hematite (Fe₂O₃), magnetite (Fe₃O₄), limonite (2Fe₂O₃•3H₂O), siderite (FeCO₃),DOCKET No.: N12179WO01 PATENTgoethite (a-FeO(OH), or a mixture thereof. The ore particles can be in the form of a powder, dust, chips, flakes, or other particulate forms.

[0010] Bentonite is an absorbent aluminum phyllosilicate clay primarily composed of montmorillonite that has the chemical formula (Na,Ca)₀.₃₃(Al,Mg)₂(Si₄O₁₀)(OH)₂·nH₂O. The phyllosilicate clay has a layered structure of an octahedral sheet of alumina between two tetrahedral sheets of silica. The different types of bentonite are typically named after the dominant compositional element, such as sodium bentonite, calcium bentonite, potassium bentonite, lithium bentonite, and aluminum bentonite. When mixed with water, bentonite swells, for example, sodium montmorillonite can swell by as much as 20 times its volume. In some embodiments, the bentonite can include montmorillonite in an amount from about 50 wt%, about 55 wt%, about 60 wt%, or about 65 wt% to about 70 wt%, about 75 wt%, about 80 wt%, or about 90 wt% or more. In some embodiments, the bentonite can be or can include sodium bentonite.

[0011] The cationic polyacrylamide copolymer can include polymer units derived from acrylamide (IUPAC Name: prop-2-enamide), acryloyloxyethyldimethylbenzylammonium chloride (IUPAC Name: benzyl-dimethyl-(2-prop-2-enoyloxyethyl)azanium;chloride), methylenesuccinic acid (IUPAC Name: Methylidenebutanedioic acid), and dimethylaminoethyl methacrylate (IUPAC Name: 2-(dimethylamino)ethyl 2-methylprop-2-enoate). In some embodiments, the cationic polyacrylamide polymer can include about 70 mol%, about 71 mol%, about 72 mol%, or about 73 mol% to about 75 mol%, about 76 mol%, about 77 mol%, or about 78 mol% of polymer units derived from the acrylamide. In some embodiments, the cationic polyacrylamide polymer can include about 16 mol%, about 17 mol%, about 17.5 mol%, or about 18 mol% to about 19 mol%, about 19.5 mol%, about 20 mol% or about 21 mol% of polymer units derived from the acryloyloxyethyldimethylbenzylammonium chloride. In some embodiments, the cationic polyacrylamide polymer can include about 3 mol%, about 3.2 mol%, about 3.4 mol%, or about 3.6 mol% to about 3.8 mol%, about 4 mol%, about 4.3 mol%, about 4.6 mol%, or about 5 mol% of polymer units derived from the methylenesuccinic acid. In some embodiments, the cationic polyacrylamide polymer can include about 3 mol%, about 3.2 mol%, about 3.4 mol%, or about 3.6 mol% to about 3.8 mol%, about 4 mol%, about 4.3 mol%, about 4.6 mol%, or about 5 mol% of polymer units derived from the dimethylaminoethyl methacrylate. In at least one embodiment, the cationic polyacrylamide polymer can include about 70 mol% to about 78 mol% of polymer units derived from the acrylamide, about 16 mol% to about 21 mol% of polymer units derived from the acryloyloxyethyldimethylbenzylammonium, about 3 mol% toDOCKET No.: N12179WO01 PATENTabout 5 mol% of polymer units derived from the methylenesuccinic acid, and about 3 mol% to about 5 mol% of polymer units derived from the dimethylaminoethyl methacrylate. In some embodiments, the cationic polyacrylamide copolymer can have a molar ratio of polymer units derived from the acrylamide: the acryloyloxyethyldimethylbenzylammonium chloride: the methylenesuccinic acid: the dimethylaminoethyl methacrylate of about 20: 5: 1: 1, respectively.

[0012] The acrylamide, acryloyloxyethyldimethylbenzylammonium chloride, methylenesuccinic acid, and dimethylaminoethyl methacrylate can be blended, mixed, or otherwise contacted with one another to produce the cationic polyacrylamide copolymer. In some embodiments, the cationic polyacrylamide copolymer can be in the form of an aqueous mixture. In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can have a pH in a range from about 2.5, about 2.7, about 3, about 3.3, about 3.5, about 3.7, or about 4 to about 4.3, about 4.5, about 4.7, about 5, about 5.3, or about 5.5. In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can have a viscosity in a range from about 300 mPa•s, about 350 mPa•s, about 400 mPa•s, or about 450 mPa•s to about 500 mPa•s, about 550 mPa•s, about 600 mPa•s, about 650 mPa•s, or about 700 mPa•s at a temperature of about 20°C.

[0013] In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can include the cationic polyacrylamide in a range from about 5 wt%, about 10 wt%, about 12, or about 14 wt% to about 16 wt%, about 18 wt%, about 20 wt%, or about 25 wt%, based on a combined weight of the cationic polyacrylamide copolymer and the water. In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can include the cationic polyacrylamide in a range from about 5 wt%, about 10 wt%, about 12, or about 14 wt% to about 16 wt%, about 18 wt%, about 20 wt%, about 25 wt%, based on the total weight of the aqueous mixture. As such, in some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can include the water in a range from about 75 wt%, about 80 wt%, about 82 wt%, about 84 wt%, or about 86 wt% to about 88 wt%, about 90 wt%, or about 95 wt%, based on the combined weight of the cationic polyacrylamide copolymer and the water. Similarly, in some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can include the water in a range from about 75 wt%, about 80 wt%, about 82 wt%, about 84 wt%, or about 86 wt% to about 88 wt%, about 90 wt%, or about 95 wt%, based on the total weight of the aqueous mixture.

[0014] In some embodiments, the cationic polyacrylamide copolymer, when in the form of an aqueous mixture, can be free from any other component or ingredient being present in anDOCKET No.: N12179WO01 PATENTamount greater than 0.07 wt%, based on the total weight of the aqueous mixture. In at least one embodiment, the cationic polyacrylamide copolymer, when in the form of the aqueous mixture, can include at least 99 wt%, at least 99.3 wt%, at least 99.5 wt%, at least 99.7 wt%, or at least 99.8 wt% of a combined amount of the cationic polyacrylamide and water, based on the total weight of the aqueous mixture.

[0015] In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can also include, but is not limited to, one or more acids, one or more nitrile compounds, one or more nitrate compounds, one or more isothiazolinone compounds, one or more chlorides, one or more phenol compounds, one or more sulfate compounds, or any mixture thereof. In some embodiments, the one or more acids can be or can include, but are not limited to, acetic acid, oxalic acid, e.g., oxalic acid dihydrate, or a mixture thereof. In some embodiments, the one or more nitrile compounds can be or can include, but are not limited to, acrylonitrile. In some embodiments, the one or more nitrate compounds can be or can include, but are not limited to, magnesium nitrate, cupric nitrate, or a mixture thereof. In some embodiments, the one or more isothiazolinone compounds can be or can include, but are not limited to, 5-chloro-2-methyl-4-isothiazolin-3-one; 2-methyl-4-isothiazolin-3-one, or a mixture thereof. In some embodiments, the one or more chlorides can be or can include, but are not limited to, magnesium chloride. In some embodiments, the one or more phenol compounds can be or can include, but are not limited to, 4-methoxyphenol. In some embodiments, the one or more sulfate compounds can be or can include, but are not limited to, sodium sulfate.

[0016] In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can independently include the one or more acids, one or more nitrile compounds, one or more nitrate compounds, one or more isothiazolinone compounds, one or more chlorides, one or more phenol compounds, one or more sulfate compounds in an amount in a range from about 0.0001 wt%, about 0.0002 wt%, about 0.0005 wt%, about 0.0007 wt%, about 0.001 wt%, about 0.0015 wt%, about 0.002 wt%, about 0.003 wt%, about 0.004 wt%, or about 0.006 wt% to about 0.008 wt%, about 0.01 wt%, about 0.02 wt%, about 0.03 wt%, about 0.04 wt%, about 0.05 wt%, about 0.05 wt%, about 0.06 wt%, about 0.07 wt%, about 0.08 wt%, about 0.09 wt%, or about 0.1 wt%, based on the total weight of the aqueous mixture. In some embodiments, the cationic polyacrylamide copolymer in the form of an aqueous mixture can include about 0.062 wt% to about 0.076 wt% of acetic acid, about 0.019 wt to about 0.024 wt% of oxalic acid dihydrate, about 0.019 wt to about 0.024 wt% of acrylonitrile, about 0.0041 wt% to about 0.0049 wt% of magnesium nitrate, about 0.0031 wt% to about 0.0033 wt% of 5-chloro-DOCKET No.: N12179WO01 PATENT2-methyl-4-isothiazolin-3-one, about 0.0023 wt% to about 0.0029 wt% of magnesium chloride, about 0.0018 wt% to about 0.0022 wt% of 4-methoxyphenol, about 0.0009 wt% to about 0.0012 wt% of 2-methyl-4-isothiazolin-3-one, about 0.00063 wt% to about 0.00077 wt% of sodium sulfate, and / or about 0.00018 wt% to about 0.00022 wt% of cupric nitrate.

[0017] In some embodiments, the anionic acrylamide-sodium acrylate copolymer can include about 25 mol%, about 27 mol%, or about 30 mol% to about 31.5 mol%, about 33.5 mol%, or about 35 mol% of polymer units derived from acrylic acid. As such, in some embodiments, the anionic acrylamide-sodium acrylate copolymer can include about 65 mol%, about 66.5 mol%, or about 68.5 mol% to about 70 mol%, about 73 mol%, or about 75 mol% of polymer units derived from acrylamide. In some embodiments, the anionic acrylamide-sodium acrylate copolymer can have an anionic charge density in a range from about 25% by weight, about 27% by weight, or about 29% by weight to about 31% by weight, about 33% by weight, or about 35% by weight.

[0018] In some embodiments, the anionic acrylamide-sodium acrylate copolymer can have a weight average molecular weight in a range from about 100,000 g / mol, about 500,000 g / mol, about 1,000,000 g / mol, about 2,000,000 g / mol, about 5,000,000 g / mol, or about 10,000,000 to about 20,000,000, about 30,000,000, about 40,000,000, or about 50,000,000. In some embodiments, the anionic acrylamide-sodium acrylate polymer and the binder including same can be free of any anionic acrylamide-sodium acrylate polymer having a weight average molecular weight of less than 100,000 g / mol. The weight average molecular weight can be determined by any routine method in the art including, for example, by gel permeation chromatography (GPC), which additionally provides molecular weight distribution information, e.g., see W. W. Yau, J. J. Kirkland and D. D. Bly, “Modern Size Exclusion Liquid Chromatography”, John Wiley and Sons, New York, 1979). In some embodiments, the anionic acrylamide-sodium acrylate copolymer can have a CAS No. of 25085-02-3.

[0019] As noted above, the anionic acrylamide-sodium acrylate copolymer, when present, can be in the form of a mixture that includes the anionic acrylamide-sodium acrylate copolymer, hydrotreated light petroleum distillates, and water. In some embodiments, the mixture of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can include about 26.4 wt%, about 27.5 wt%, about 28.5 wt%, or about 29.4 wt% to about 30 wt%, about 30.8 wt%, about 31.6 wt%. or about 32.3 wt% of the anionic acrylamide-sodium acrylate polymer, based on a combined weight of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water. In some embodiments, the mixture of the anionic acrylamide-sodium acrylate copolymer, theDOCKET No.: N12179WO01 PATENThydrotreated light petroleum distillates, and the water can include about 19.6 wt%, about 20.4 wt%, about 21 wt%, or about 21.8 wt% to about 22.4 wt%, about 23 wt%, about 23.6 wt%, or about 24.1 wt% of the hydrotreated light petroleum distillates, based on the combined weight of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water. In some embodiments, the mixture of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can include about 43.9 wt% about 45 wt%, about 47 wt%, or about 48.8 wt% to about 50 wt%, about 51.5 wt%, about 52.5 wt%, or about 53.7 wt% of the water, based on the combined weight of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water.

[0020] In some embodiments, the mixture of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can include about 26.4 wt% to about 32.3 wt% of the anionic acrylamide-sodium acrylate copolymer, about 19.6 wt% to about 24.1 wt% of the hydrotreated light petroleum distillates, and about 43.9 wt% to about 53.7 wt% of the water, based on the combined weight of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water. In other embodiments, the mixture of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can include about 43.9 wt% to about 53.7 wt% of the water, about 26.4 wt% to about 32.3 wt% of the anionic acrylamide-sodium acrylate copolymer, and about 19.6 wt% to about 24.1 wt% of the hydrotreated light petroleum distillates, based on a total weight of the mixture that includes the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water.

[0021] In some embodiments, the mixture that includes the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can also include, but is not limited to, one or more oxyalkylated alcohols, one or more polyol esters, one or more fatty acid esters, one or more organic salts, one or more carboxylic acid salts, or a mixture thereof. In some embodiments, the oxyalkylated alcohol can be or can include, but is not limited to, one or more ethoxylated C10-C16 alcohols. In some embodiments, the polyol ester can be or can include, but is not limited to, ethoxylated sorbitan monostearate. In some embodiments, the fatty acid ester can be or can include, but is not limited to, sorbitan monooleate. In some embodiments, the organic salt can be or can include, but is not limited to, tetrasodium EDTA. In some embodiments, the carboxylic acid salt can be or can include, but is not limited to, sodium formate.DOCKET No.: N12179WO01 PATENT

[0022] In some embodiments, the mixture that includes the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can include the one or more oxyalkylated alcohols in an amount from about 0.1 wt%, about 0.5 wt%, or about 1 wt% to about 1.5 wt%, about 1.8 wt%, about 2.2 wt%, or about 2.5 wt% based on a total weight of the mixture. In some embodiments, the mixture can include the one or more polyol esters in an amount from about 0.1 wt%, about 0.5 wt%, or about 1 wt%, to about 1.2 wt%, about 1.4 wt%, or about 1.6 wt%, based on the total weight of the mixture. In some embodiments, the mixture can include the one or more fatty acid esters in an amount from about 0.1 wt%, about 0.3 wt%, or about 0.6 wt% to about 0.8 wt%, about 1 wt%, or about 1.2 wt%, based on the total weight of the mixture. In some embodiments, the mixture can include the one or more organic salts in an amount from about 0.001 wt%, about 0.01 wt%, or about 0.02 wt% to about 0.025 wt%, about 0.03 wt%, or about 0.034 wt%, based on the total weight of the mixture. In some embodiments, the mixture can include the one or more carboxylic acid salts in an amount from about 0.001 wt%, about 0.004 wt%, or about 0.008 wt% to about 0.009 wt%, about 0.01 wt%, or about 0.02 wt%, based on the total weight of the mixture. In some embodiments, the mixture of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can include at least 93 wt%, at least 94 wt%, at least 95 wt%, or at least 96 wt% of a combined amount of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water, based on the total weight of the mixture.

[0023] In some embodiments, the mixture that includes the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water can have a viscosity in a range from about 300 mPa•s, about 400 mPa•s, about 500 mPa•s, about 650 mPa•s, about 800 mPa•s, about 1,000 mPa•s, or about 1,250 mPa•s to about 1,500 mPa•s, about 1,750 mPa•s, about 2,000 mPa•s, about 2,250 mPa•s, about 2,500 mPa•s, about 2,750 mPa•s, or about 3,000 mPa•s at a temperature of about 20°C.

[0024] In some embodiments, the hydrotreated light petroleum distillates can include a mixture of hydrotreated isoparaffins and naphthenics. In some embodiments, the hydrotreated light petroleum distillates can include a relatively low amount of polynuclear aromatics. The hydrotreated light petroleum distillates is also referred to or otherwise known as paraffinic naphthenic solvent or aliphatic solvent. In other embodiments, the hydrotreated light petroleum distillates can include light catalytically cracked petroleum distillates. In still other embodiments, the hydrotreated light petroleum distillates can include C16-C28 paraffins. In some embodiments, the hydrotreated light petroleum distillates can have a CAS No. of 64742-DOCKET No.: N12179WO01 PATENT47-8, a CAS No. of 68921-07-3, a CAS No. of 97862-82-3, or a mixture thereof. In some embodiments, suitable hydrotreated light petroleum distillate products can include LPA® 142 solvent that has an initial boiling point of about 176.6°C and an end boiling point of about 221.1°C, LPA® 170 solvent that has an initial boiling point of about 198.8°C and an end boiling point of about 248.8°C, and LPA® 210 solvent that has an initial boiling point of about 237.8°C and an end boiling point of about 285°C, where the boiling points are measured according to ASTM D-86-23ael, all manufactured by Sasol.

[0025] The water can be any type of water, e.g., treated tap water, distilled water, deionized water, untreated well-water, and the like. In some embodiments, at least a portion of the water can be sterile, purified water, such as water assigned a CAS No. of 7732-18-5. In some embodiments, the water can include a mixture of two or more different types of water, e.g., a mixture of deionized water and tap water or a mixture of deionized water and distilled water or a mixture of deionized water and untreated well-water. For example, in some embodiments, the cationic polyacrylamide polymer can include

[0026] In some embodiments, the pelletized product can include the bentonite in an amount from about 0.7 wt%, about 0.75 wt%, about 0.8 wt%, about 0.85 wt%, about 0.9 wt%, about 0.95 wt%, or about 1 wt% to about 1.1 wt%, about 1.2 wt%, about 1.3 wt% about 1.4 wt%, about 1.5 wt%, about 1.6 wt%, about 1.7 wt%, or about 1.8 wt%, based on a dry weight of the plurality of ore particles. In some embodiments, the pelletized product can include a combined amount of any of the cationic polyacrylamide copolymer present and any of the anionic acrylamide-sodium acrylate copolymer present in an amount from about 0.001 wt%, about 0.0015 wt%, about 0.003 wt%, about 0.004 wt%, about 0.006 wt%, about 0.008 wt%, about 0.01 wt%, about 0.015 wt%, about 0.02 wt%, about 0.024 wt%, or about 0.028 wt% to about 0.03 wt%, about 0.035 wt%, about 0.04 wt%, about 0.045 wt%, about 0.05 wt%, or about 0.055 wt%, based on the dry weight of the plurality of ore particles.

[0027] In some embodiments, the pelletized product can include the cationic polyacrylamide polymer in an amount from 0.001 wt%, about 0.0015 wt%, about 0.002 wt%, about 0.003 wt%, about 0.004 wt%, about 0.005 wt%, about 0.006 wt%, about 0.007 wt%, about 0.008 wt%, or about 0.009 wt% to about 0.01 wt%, about 0.011 wt%, about 0.012 wt%, about 0.013 wt%, about 0.014 wt%, about 0.015 wt%, about 0.016 wt%, about 0.017 wt%, about 0.018 wt%, about 0.019 wt%, or about 0.02 wt%, based on the dry weight of the plurality of ore particles. In some embodiments, the pelletized product can include the anionic acrylamide-sodium acrylate copolymer in an amount from about 0.0024 wt%, about 0.0026 wt%, about 0.0028 wt%, about 0.003 wt%, about 0.004 wt%, about 0.006 wt%, about 0.008 wt%, or about 0.01DOCKET No.: N12179WO01 PATENTwt% to about 0.015 wt%, about 0.017 wt%, about 0.019 wt%, about 0.02 wt%, about 0.024 wt%, about 0.026 wt%, about 0.028 wt%, about 0.03 wt%, or about 0.032 wt%, based on the dry weight of the plurality of ore particles. In some embodiments, the pelletized product can include the hydrotreated light petroleum distillates in an amount from about 0.0018 wt%, about 0.0021 wt%, about 0.003 wt%, about 0.005 wt%, about 0.007 wt%, or about 0.009 wt% to about 0.01 wt% to about 0.013 wt%, about 0.016 wt%, about 0.018 wt%, about 0.021 wt%, or about 0.024 wt%, based on the dry weight of the plurality of ore particles.

[0028] The formation of pelletized products that contain a plurality of ore particles and a binder is well-known. The pelletized product can be formed by mixing the plurality of ore particles with the binder to produce a mixture. In some embodiments, the ore particles can have an average cross-sectional length in a range from about 0.1 pm, about 1 pm, about 10 pm, about 25 pm, or about 50 pm to about 75 pm, about 100 pm, about 125 pm, about 150 pm, about 175 pm, or about 200 pm.

[0029] The mixture can be pelletized to produce a plurality of pellets that are often referred to as “green pellets” or “green balls”. For example, the mixture can be blended together in a mixer and fed to a balling disc or balling drum to produce the plurality of pellets. The pellets can have an average cross-sectional length, e.g., diameter, in a range from about 5 mm, about 7 mm, or about 9 mm to about 12 mm, about 14 mm, or about 16 mm.

[0030] The green pellets, after drying, can have a green compressive strength (GCS) that can be sufficient to permit the pellets to be further processed, e.g., transfer via a conveyer belt to an induration furnace, without falling apart or otherwise disintegrating. The green pellets can be heated, e.g., to a temperature of about 100°C to about 350°C, to produce dried green pellets. In some embodiments, the dried green pellets can have a green compressive strength in a range from about 30 N / pellet, about 35 N / pellet, about 40 N / pellet, or about 45 N / pellet to about 50 N / pellet, about 55 N / pellet, about 60 N / pellet, about 65 N / pellet, about 70 N / pellet, or about 75 N / pellet.

[0031] The dried green pellets can have a drop number (Drop #) in a range from 2, 3, or 4 to 5, 6, or 7. The drop number of dried green pellets can be measured by dropping the dried green pellets onto a mild steel plate from a height of 45 cm until the dried green pellets develop cracks or crumble. The drop number gives the average number of drops before a fracture is observed. In determining the drop number, a plurality of dried green pellets, e.g., five pellets, can be measured and the average value can be calculated. The drop number provides an indication of the dried green pellets ability to remain intact during handling, e.g., transfer via a conveyer belt to an induration furnace.DOCKET No.: N12179WO01 PATENT

[0032] In some embodiments, the green pellets can be heated to a relatively high temperature to produce a plurality of fired or heat-hardened pellets. In some embodiments, the green pellets can be introduced into and heated within an indurating furnace to produce the plurality of fired pellets. In some embodiments, the induration furnace can include multiple steps or zones. In some embodiments, the green pellets can be heated in a first step to a temperature in a range from about 200°C to about 350°C to produce a plurality of dried green pellets. The dried green pellets can then be heated in a second step to a temperature in a range from about 1,175°C, about 1,200, or about 1,225°C to about 1,250°C, about 1,300°C, about 1,350°C, or about 1,375°C to produce a plurality of sintered or fired pellets. The dried pellets can then be heated in the second step for a time period in a range from about 30 minutes, about 35 minutes, or about 40 minutes to about 55 minutes, about 60 minutes, or about 80 minutes to produce the fired pellets. The fired pellets can then be cooled in a third step and discharged from the indurating furnace.

[0033] In some embodiments, the fired pellets can have a cold compressive strength (CCS) in a range from about 5,000 Newtons per pellet (N / pellet), about 5,500 N / pellet, about 6,000 N / pellet, or about 6,500 N / pellet to about 7,000 N / pellet, about 7,500 N / pellet, about 8,000 N / pellet, about 8,500 N / pellet, or about 9,000 N / pellet. The cold compressive strength of fired pellets can be measured using a Zwick Roell compressive machine (Model No: BT2-FR020TN. A50). The fired pellets can have an average diameter in a range from about 10 mm to about 13 mm. The fired pellets subjected to the cold compressive strength test can be whole pellets, i.e., broken and chipped pellets can be excluded. The pellet can be placed at the center of the lower platen of the testing machine. The load was applied at a 5 mm / min speed of compression platen on each pellet. The load at which the pellets break can be recorded. The measuring electronics for the force measurement can comply with ISO 7500-1, ASTM E4, and JIS B7721. The test can be repeated for ten pellets and an average load of the repeated test can be reported as a cold compressive strength of the fired pellets.

[0034] In some embodiments, the fired pellets can have an apparent porosity (AP) in a range from about 6%, about 7%, about 8%, or about 9% to about 11%, about 12%, about 13%, about 14%, about 15%, or about 16%. The apparent porosity can be measured by the immersion method. The fired pellets can have an average diameter in a range from about 10 mm to about 13 mm. The fired pellets can be weighed in air, then suspended in kerosene oil to measure the suspended weight. The pellets can then be soaked in the kerosene oil at room temperature, removed from the kerosene oil, and measured again to obtain the soaked weight. The apparent porosity can be determined based on the equation:DOCKET No.: N12179WO01 PATENT% AP = ■■ x 100,ir.;- W'sivwhere W_A is the weight (in grams) of the fired pellet in air, W_S is the soaked weight (in grams) of the fired pellet in the oil, and W_SW is the suspended weight (in grams) of the pellet.

[0035] In some embodiments, the fired pellets can have a reduction degradation index (RDI) in a range from about 5%, 6%, 7%, 8%, 9% or 10% to 11%, 12%, 13%, 14%, 15%, or 16%. In some embodiments, the fired pellets can have a reduction degradation index of less than 16%, less than 15%, less than 14%, less than 13%, less than 12%, or less than 11%. The reduction degradation index can be measured according to Japanese standard JIS: M8720 (2001). The reacting vessel containing 500 g of sample can be placed inside the heating chamber, and N2 gas can be allowed to pass through the reacting vessel at 5 Itr / min. The temperature can be raised to 550°C and be allowed to stabilize at that temperature for 10 minutes. N2 gas flow can be stopped, and a mixture of 70% N2 and 30% CO gas can be passed for 30 minutes after drying the gas by passing it through KOH solution, pyrogallol solution, and silica gel. The vessel can then be cooled to room temperature under the flow of N2 gas at 5 Itr / min. The cold sample can be taken out and rotated in a drum (200 mm length and 130 mm ID, having two lifters) for 30 minutes at 30 rpm. The sample can then be screened through a 3.15 mm size screen, and the RDI value can be calculated based on the equation:RDI = Weight of −3.15 mm sample fraction / Weight of sample used in the experiment × 100.

[0036] In some embodiments, the fired pellets can have a reducibility index (RI) in a range from about 30%, about 33%, about 35%, about 37%, about 40%, or about 43% to about 47%, about 50%, about 53%, about 55%, about 60%, about 65%, or more. The reducibility index can be measured according to the JIS M8713(2000) standard test procedure. The reacting vessel containing 500 g of sample can be placed inside the heating chamber, and N2 gas can be allowed to pass through the reacting vessel at 5 ltr / min. The temperature can be raised to 900°C and can be allowed to stabilize at that temperature for 10 minutes. N2 gas flow can be stopped, and a mixture of 70% N2 and 30% CO gas can be passed for 180 minutes after drying the gas by passing it through KOH solution, pyrogallol solution, and silica gel. The vessel can then be cooled to room temperature under flow of a N2 gas at 5 Itr / min. The cold sample can then be taken out, and the weight can taken via a digital electronic balance. The reducibility index value can be calculated based on the equation:Loss in weight of the sampeWeight of oxygen initially available in the sampleDOCKET No.: N12179WO01 PATENT

[0037] In some embodiments, the fired pellets can have a tumbler index (+6.3 mm) in a range from about 90%, about 92%, or about 94% to about 96%, about 98%, about 99%, or about 99.5%. In some embodiments, the fired pellets can have an abrasion index (-0.5 mm) in a range from about 0.1%, about 0.3%, about 0.5%, or about 0.7% to about 1%, about 2%, about 4%, about 6%, about 8%, or about 10%. In some embodiments, the fired pellets can have an abrasion index (-0.5 mm) of less than 9%, less than 7%, less than 5%, less than 3%, less than 2%, or less than 1.5%. The tumbler index and abrasion index can be measured according to the ISO 3271(2015) standard test procedure.

[0038] In some embodiments, the pelletized product can also include one more additional ingredients or components. In some embodiments, one or more fluxing agents and / or one or more fuel sources can be combined with the plurality of ore particles and the binder to produce the mixture that can be mixed and formed into the pelletized product. In some embodiments, the fluxing agent can be or can include, but is not limited to, lime, dolomite, colemanite, or a mixture thereof. In some embodiments, fuel source can be or can include, but is not limited to, coke, anthracite coal, or other fuel can often be added that can combust during firing of the pelletized product in an indurating furnace to produce a fired pelletized product. In some embodiments, when the binder includes the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates mixed therewith can also serve as a fuel source.Examples

[0039] In order to provide a better understanding of the foregoing discussion, the following non-limiting examples are offered. Although the examples are directed to specific embodiments, they are not to be viewed as limiting the invention in any specific respect. All parts, proportions, and percentages are by weight unless otherwise indicated.

[0040] A comparative example (CEx. 1) that included a plurality of pellets that were made with iron ore particles and bentonite was prepared. Five inventive examples (Ex. 1-5) that included a plurality of pellets that were made with iron ore particles, bentonite, and the cationic polyacrylamide copolymer (Ex. 1) or both the cationic polyacrylamide copolymer and the anionic acrylamide-sodium acrylate copolymer (Ex. 2-4) or the anionic acrylamide-sodium acrylate copolymer (Ex. 5) were also prepared. The iron ore contained about 69.30 wt% of Fe, about 15.29 wt% of FeO, about 2.97 wt% of SiO2, and about 0.27 wt% of Al2O3, and had a Blaine number of about 1,720 cm2 / g. The bentonite contained about 2.69 wt% of Fe, about 0.28 wt% of FeO, about 50.54 wt% of SiO2, and about 16.08 wt% of Al2O3, had a loss on ignition (LOI) of about 14.99 wt%, and a Blane number of about 2,015 cm2 / g.DOCKET No.: N12179WO01 PATENT

[0041] The amount of iron ore used to make the pellets in each example was 5,000 grams. The amount of each additional component used to make the pellets in each example are shown in Table 1 below. The weight percent of the bentonite is based on the weight of the iron ore, i.e., 5,000 grams of iron ore. The amount of the cationic copolymer and the anionic copolymer was based on grams per metric ton of iron ore.

[0042] The drop number and green compressive strength for dried green pellets in each example were measured. The drop number for each example was determined by taking the average drop number for five pellets in each example. The green pellets that were not tested were fired to produce fired pellets and the cold compressive strength (CCS) of the fired pellets was also measured. The pellets that were evaluated in the examples had an average diameter of about 10 mm to about 13 mm.Table 1Cationic AnionicApparent Bentonite Copolymer Copolymer Drop GCS CCSExample Porosity (wt%) (g / metric (g / metric # (N / pellet) (N / pellet)ton) ton) (%) CEx. 1 1.85 0 0 3 61.39 6,335 14.87 Ex. 1 1.35 350 0 2 51.58 7,267 13.83 Ex. 2 1.20 100 200 2 51.58 8,130 13.51 Ex. 3 1.00 200 200 2 49.62 6,237 9.13 Ex. 4 0.80 350 200 3 39.82 5,453 8.21Ex. 5 0.80 0 550 5 53.54 6,031 10.63

[0043] The CCS of fired pellets is one of the most important parameters for a fired pellet to be qualified for feeding into electric arc and blast furnaces. As shown in Table 1, when only bentonite was used (CEx. 1), the CCS was 6,335 N / pellet. As the amount of bentonite was reduced from 1.85 wt% to 1 wt% (Ex. 1 to Ex. 3), the CCS remained comparable to or greater than the CSS of CEx. 1 when only bentonite was used. As the amount of bentonite was further reduced (Ex. 4 and Ex. 5), the CCS dropped further to 5,453 N / pellet and 6,031 N / pellet, respectively. The CCS of the pellets in Ex. 4 and Ex. 5 may be considered less than ideal. As such, in some embodiments, a useful green pellet formulation can be to reduce the bentonite from 1.85 wt% to 1.00 wt% and to add 200 g of the cationic copolymer per metric ton of iron ore and 200 g of the anionic copolymer per metric ton of iron ore. As such, in some embodiments, the amount of bentonite used to make green pellets can be reduced by about 46DOCKET No.: N12179WO01 PATENTwt% via the addition of about 200 g / metric ton of the cationic copolymer and about 200 g / metric ton of the anionic copolymer, while maintaining an acceptable CCS in the fired pellets.

[0044] It has been observed in literature that when organic binders are used 100% to prepare iron ore pellets, the apparent porosity of such prepared pellets increases as compared to pellets prepared from 100% bentonite. The apparent porosity of the pellets prepared in Ex. 1-5, however, did not increase as compared to the porosity of the CEx. pellets that used only bentonite. Without wishing to be bound by theory, the lack of an increase in the apparent porosity could be because the amount of the bentonite replaced by the cationic copolymer and / or the anionic copolymer did not cross a minimum threshold percent value of the bentonite.

[0045] In addition to the properties shown in Table 1 for the fired pellets of Ex. 3, the tumbler index, abrasion index, reducibility index, and reduction degradation index were further measured. The results are shown in Table 2 below.Table 2Tumbler Index (+6.3 mm) 98.40%Abrasion Index (-0.5 mm) 1.04%Reducibility Index 43.27%Reduction Degradation Index 10.37%

[0046] Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any lower value with any upper value, the combination of any two lower values, and / or the combination of any two upper values are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values are "about" or "approximately" the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0047] Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.DOCKET No.: N12179WO01 PATENT

[0048] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

DOCKET No.: N12179WO01 PATENTClaims:What is claimed is:

1. A pelletized product, comprising:a plurality of ore particles; anda binder comprising bentonite and at least one of a cationic polyacrylamide copolymer and an anionic acrylamide-sodium acrylate copolymer, wherein:the cationic polyacrylamide copolymer, if present, comprises polymer units derived from four monomers, andthe anionic acrylamide-sodium acrylate copolymer, if present, is in the form of a mixture comprising the anionic acrylamide-sodium acrylate copolymer, hydrotreated light petroleum distillates, and water.

2. The pelletized product of claim 1, wherein the pelletized product comprises about 0.8 wt% to about 1.7 wt% of the bentonite and about 0.004 wt% to about 0.045 wt% of a combined amount of any of the cationic polyacrylamide copolymer present and of any of the anionic acrylamide-sodium acrylate copolymer present, wherein all weight percent values are based on a dry weight of the plurality of ore particles.

3. The pelletized product of claim 1 or claim 2, wherein the binder comprises the cationic polyacrylamide copolymer.

4. The pelletized product of claim 3, wherein the cationic polyacrylamide copolymer comprises polymer units derived from acrylamide, acryloyloxyethyldimethylbenzylammonium chloride, methylenesuccinic acid, and dimethylaminoethyl methacrylate.

5. The pelletized product of claim 4, wherein the cationic polyacrylamide polymer comprises about 70 mol% to about 78 mol% of polymer units derived from the acrylamide, about 16 mol% to about 21 mol% of polymer units derived from the acryloyloxyethyldimethylbenzylammonium chloride, about 3 mol% to about 5 mol% of polymer units derived from the methylenesuccinic acid, and about 3 mol% to about 5 mol% of polymer units derived from the dimethylaminoethyl methacrylate.DOCKET No.: N12179WO01 PATENT6. The pelletized product of any one of claims 2 to 5, wherein the cationic polyacrylamide copolymer is in the form of an aqueous mixture comprising about 10 wt% to about 20 wt% of the cationic polyacrylamide copolymer, based on a combined weight of the cationic polyacrylamide copolymer and water.

7. The pelletized product of any one of claims 1 to 6, wherein the binder comprises the anionic acrylamide- sodium acrylate copolymer.

8. The pelletized product of claim 7, wherein the mixture comprising the anionic acrylamide- sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water comprises about 26.4 wt% to about 32.3 wt% of the anionic acrylamide-sodium acrylate copolymer, about 19.6 wt% to about 24.1 wt% of the hydrotreated light petroleum distillates, and about 43.9 wt% to about 53.7 wt% of the water, based on a combined weight of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water.

9. The pelletized product of claim 7 or claim 8, wherein the anionic acrylamide-sodium acrylate copolymer comprises about 25 mol% to about 35 mol% of polymer units derived from acrylic acid and about 65 mol% to about 75 mol% of polymer units derived from acrylamide, and wherein the anionic acrylamide-sodium acrylate copolymer has an anionic charge density in a range from about 25% by weight to about 35% by weight.

10. The pelletized product of any one of claims 7 to 9, wherein the anionic acrylamide-sodium acrylate copolymer has a weight average molecular weight in a range from about 100,000 g / mol to about 50,000,000 g / mol.

11. The pelletized product of any one of claims 1 to 10, wherein the pelletized product comprises about 0.0015 wt% to about 0.015 wt% of the cationic polyacrylamide polymer and about 0.0028 wt% to about 0.028 wt% of the anionic acrylamide-sodium acrylate copolymer, based on a dry weight of the plurality of ore particles.

12. The pelletized product of any one of claims 1 to 11, wherein the plurality of ore particles comprises iron ore.DOCKET No.: N12179WO01 PATENT13. The pelletized product of any one of claims 1 to 12, wherein the binder further comprises lime, dolomite, colemanite, or a mixture thereof.

14. The pelletized product of claim 1, wherein:the pelletized product is made by mixing the plurality of ore particles and the binder to produce a mixture and pelletizing the mixture to produce the pelletized product,the plurality of ore particles has a moisture concentration of less than 5 wt%, based on the weight of the plurality of ore particles, andthe binder comprises the anionic acrylamide-sodium acrylate copolymer.

15. The pelletized product of claim 1, wherein:the pelletized product is made by mixing the plurality of ore particles and the binder to produce a mixture and pelletizing the mixture to produce the pelletized product,the plurality of ore particles has a moisture concentration in a range from about 5 wt% to about 8 wt%, andthe binder comprises the cationic polyacrylamide copolymer and the anionic acrylamide-sodium acrylate copolymer.

16. The pelletized product of claim 1, wherein:the pelletized product is made by mixing the plurality of ore particles and the binder to produce a mixture and pelletizing the mixture to produce the pelletized product,the plurality of ore particles has a moisture concentration of greater than 8 wt%, and the binder comprises the cationic polyacrylamide copolymer.

17. A process for pelletizing particles, comprising:mixing a plurality of ore particles with a binder to produce a mixture, wherein:the binder comprises bentonite and at least one of a cationic polyacrylamide copolymer and an anionic acrylamide-sodium acrylate copolymer,the cationic polyacrylamide copolymer, if present, comprises polymer units derived from four monomers, andthe anionic acrylamide-sodium acrylate copolymer, if present, is in the form of a mixture comprising the anionic acrylamide-sodium acrylate copolymer, water, and hydrotreated light petroleum distillates; andpelletizing the mixture to produce a pelletized product.DOCKET No.: N12179WO01 PATENT18. The process of claim 17, further comprising:introducing the pelletized product into an indurating furnace; andheating the pelletized product within the indurating furnace to produce a plurality of fired pellets.

19. The process of claim 17 or claim 18, wherein the binder comprises the cationic polyacrylamide copolymer, and wherein the cationic polyacrylamide copolymer comprises polymer units derived from acrylamide, acryloyloxyethyldimethylbenzylammonium chloride, methylenesuccinic acid, and dimethylaminoethyl methacrylate.

20. The process of any one of claims 17 to 19, wherein the binder comprises the mixture comprising the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water, and wherein the mixture comprising the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water comprises about 26.4 wt% to about 32.3 wt% of the anionic acrylamide-sodium acrylate copolymer, about 19.6 wt% to about 24.1 wt% of the hydrotreated light petroleum distillates, and about 43.9 wt% to about 53.7 wt% of the water, based on a combined weight of the anionic acrylamide-sodium acrylate copolymer, the hydrotreated light petroleum distillates, and the water.

Images