Binder composition for the production of metal ore pellets, method for producing pellets, and metal ore pellets

Abstract

The present invention relates to a binder composition for cold compaction of metal ore pellets. The binder composition comprises a hydraulic binder component and an additive. The hydraulic binder component has a fineness of at least D95<40 μm, D50<12 μm, and D10<5 μm (determined by a laser diffraction particle size analyzer), and a Blaine fineness of 6500-9000 cm 2 / g. The CaO content is >62.5 wt.% and the C3S content is >60 wt.%, preferably >65 wt.%.

Description

Technical Field

[0001] The present invention relates to a binder composition for the production of metal ore pellets, a method for the production of metal ore pellets, and metal ore pellets.

Background Art

[0002] Ores with fine particle sizes, such as crushed ores, powdered ores, or ores as concentrates, cannot be processed in metallurgical processes such as blast furnaces or direct reduction.

[0003] Generally, in metallurgical processes of ores, such as those for liquid metals or direct reduction of ores, a gas flow between particles is required. A suitable low flow resistance must be ensured. Therefore, it is well known to increase the particle size, for example, by pelletizing the ore to obtain pellets of a suitable size or by sintering the ore to increase the particle size.

[0004] In a blast furnace, depending on the height of the furnace, a large pressure is applied to the bulk weight, and thus to the pellets. Also, the pellets are exposed to compression as well as friction and wear during transportation and handling.

[0005] Therefore, pellets having sufficient compressive strength are required.

[0006] It is known to sinter ore particles into larger particles suitable for further processing. Sintering is a process that consumes a large amount of energy and usually requires additional use of coke. This releases greenhouse gases.

[0007] In conventional dry metallurgical processes, the ore is pelletized by partial melting. A disadvantage of this method is that additional energy is required before actually processing the ore to extract the desired metal.

[0008] In related industries, the cold pelletization process is known and used. Pellets are manufactured using various types of binders. It is known that ore can be pelletized using Portland cement, and it is also known that using fine Portland cement can improve the strength of the pellets. A major limitation in these processes is that the compressive strength of the pellets may decrease over time, which may not be sufficient to support the handling of the pellets. Such pellets are thought to be crushed during handling before or during the metallurgical process.

[0009] High-alumina cements, such as calcium aluminate cement and calcium sulfoaluminate cement, are also used in the manufacture of pellets. However, these binders are very expensive.

[0010] Furthermore, it is known that the compressive strength of ore pellets can be improved by hardening them using a hydraulic binder. For example, it is known that hardening pellets in a saturated gas stream containing high levels of CO2 improves their strength. This is considered an effective means of achieving the desired strength and also a method that utilizes CO2-containing waste gas. In addition, a hardening method involving the introduction of saturated steam treatment in an autoclave is known.

[0011] In addition, it is known that curing the pellets at an appropriate temperature within a saturated vapor gas environment can improve their cold strength or reduce the curing time.

[0012] Patent Document 1 (Soviet Patent No. 562580) relates to the preparation of uncalcined iron ore pellets using a flux, and describes mixing iron ore with hydraulic cement and a catalyst. The cement is an allite-based cement containing more than 50% allite. In addition to alumina cement, calcium chloride and barium chloride are used as catalysts. After pelletizing, the mixture is hardened at 150-180°C for 2 hours, and then heated to 250°C under normal atmospheric pressure. This yields a compressive strength of 200 kg / pellet or more than 2000 N.

[0013] Patent document 2 (U.S. Patent No. 3,676,104) describes a binder for the production of pellets consisting of blast furnace slag and Portland cement. In addition to the ore, there are 5% cement and 10% blast furnace slag. The pellets are hardened in a steam autoclave.

[0014] Patent Document 3 (International Publication No. 2019 / 033187) relates to a method for cold forming pellets from very fine iron ore particles with a particle size of up to 0.8 mm and cement in which 98% have a particle size of less than 44 μm.

[0015] From Patent Document 4 (British Patent No. 1445792), it is known that a mixture containing 15-95% cement, 5-85% powder containing free iron, and 2-40% iron ore is mixed together. [Prior art documents] [Patent Documents]

[0016] [Patent Document 1] Soviet Patent No. 562580 Specification [Patent Document 2] U.S. Patent No. 3676104 [Patent Document 3] International Publication No. 2019 / 033187 [Patent Document 4] British Patent No. 1445792 [Overview of the Initiative]

Problems to be Solved by the Invention

[0017] Today, iron ore pellets supplied to blast furnaces and DR reactors are generally produced by sintering or firing pellets containing binders such as organic substances or bentonite. In these two processes, an agglomeration process occurs due to partial reduction in the ore and melting of iron oxide. In this hardening process, heavy equipment, a large amount of fuel, and energy are required, and a large amount of greenhouse gas is emitted.

[0018] An object of the present invention is to provide a binder composition for pelletizing metal ores that can produce pellets having sufficient compressive strength.

Means for Solving the Problems

[0019] The above object is achieved by the binder composition according to claim 1.

[0020] Embodiments are claimed in the claims dependent on claim 1.

[0021] A further object of the present invention is to provide a method for producing metal ore pellets having sufficient compressive strength, in which the energy of the process is optimized.

[0022] The above object is achieved by a method having the features of claim 8.

[0023] Embodiments are claimed in the claims dependent on claim 8.

[0024] A further object of the present invention is to provide metal ore pellets having sufficient compressive strength for handling and processing. This object is achieved by the metal ore pellets according to claim 15.

[0025] The percentages shown below are values in % by weight, unless otherwise specified.

[0026] The binder composition according to the present invention, which includes a specific hydraulic binder, can produce pellets with sufficient compressive strength without performing any additional energy-consuming processing steps.

[0027] This invention significantly reduces CO2 emissions and energy consumption in the production of iron ore pellets. Furthermore, the required equipment can be simplified.

[0028] Contrary to the experience described in conventional technologies, compressive strength does not decrease, but rather increases, during the later stages of the hydraulic reaction. Furthermore, contrary to common knowledge in the relevant technical field, it was found that the pellets' ability to possess sufficient strength is not solely due to the fineness of the hydraulic binder; other criteria must also be met.

[0029] The hydraulic binder has a fineness in the range of D95 < 40 μm, D50 < 12 μm, and D10 < 5 μm (determined by a laser diffraction particle size analyzer), and a Blaine fineness of 6500 to 9000 cm². 2 Any hydraulic binder between / g may be selected.

[0030] Furthermore, the CaO content is preferably greater than 62.5% by weight, and the C3S content is >60% by weight, preferably >65% by weight. In particular, the hydraulic binder is advantageous if it meets the following criteria: Al2O3 > 4% by weight, Fe2O3 < 3% by weight, SO3 > 3.5% by weight, C3A > 2% by weight (by XRD-Rietveld analysis), C4AF < 11% by weight (by XRD-Rietveld analysis).

[0031] In addition to the hydraulic binder, the binder composition includes additives. The additives may be one or more from the group including alkanolamines, gypsum, calcium aluminate cement, iron sulfate, calcium chloride and magnesium chloride, sodium sulfoaluminate, CSH seeds, carboxymethylcellulose, carboxymethyl hydroxyethylcellulose, vinyl copolymers, sodium citrate, sodium gluconate, disodium salt of ethylenediaminetetraacetic acid, melamine formaldehyde condensate and naphthalene formaldehyde condensate, lignosulfonates, set retardants, superplasticizers, fluxes such as finely ground limestone and / or dolomite.

[0032] It was found that the presence of an organic additive is advantageous, and that this organic additive may be selected from the group of alkanolamines.

[0033] Alkanolamines are compounds that contain both hydroxyl (-OH) and amino (-NH2, -NHR, and -NR2) functional groups in an alkane skeleton. The term alkanolamine is a broad category. Alkanolamines are preferably selected from the group including N,N bis-(2-hydroxyethyl)-2-propanolamine (DIEPA), N,N bis-(2-hydroxypropyl)-N-(hydroxyethyl)amine (EDIPA), diethanolamine (DEA), triethanolamine (TEA), triisopropanolamine (TIPA), triethylenetetramine (TETA), triethylenepentamine (TEPA), hydroxyethyldiethylenetriamine (HEDETA), aminoethylethanolamine (AEEA), and combinations thereof.

[0034] In particular, tri-isopropanolamine, di-ethanol-isopropanolamine, or mixtures thereof can be used.

[0035] The amount of alkanolamine added may be 0.1% to 1% by weight of the total amount of the binder composition.

[0036] In addition to alkanolamines, gypsum may be further added as a source of calcium sulfate as part of the hydraulic binder. The amount added may be 0.5% to 10% by weight.

[0037] The additive may contain calcium aluminate cement, which may be any calcium aluminate cement, any calcium sulfoaluminate cement, or any mixture thereof.

[0038] Calcium aluminate may be present in an amount between 2% and 20% by weight, based on the total weight of the binder.

[0039] Iron sulfate may be added as an additive, preferably up to 5% by weight based on the total weight of the hydraulic binder components.

[0040] Other suitable additives may include calcium chloride and magnesium chloride, sodium sulfoaluminate, CSH seeds, carboxymethylcellulose, vinyl copolymers, and any mixture thereof.

[0041] Finely ground limestone and / or dolomite can be added to the binder as a flux. The amount of mineral added depends on the composition of the ore and the chemical composition of the cold-bonded pellets.

[0042] In the method of the present invention, fine ore may be mixed with a dry binder component. The binder component may optionally be added in an amount of 2 to 12% by weight of the total weight of the pellets, preferably in an amount of 4 to 8% by weight of the total weight of the dry pellets (ore + binder + optional additives).

[0043] The water content of the ore may preferably be 3% to 15% by weight, based on the total weight of the ore.

[0044] The water contained in the ore can be used for the hydraulic reaction of the binder and for good adhesion of the binder particles to the ore particles.

[0045] If the water content of the ore is less than 3% by weight, water may be added. If the water content is greater than 15% by weight, the ore may be partially dried to achieve the desired water content. Furthermore, the water content can be determined not only by the ore but also by the fineness of the binder.

[0046] If the water content of the ore falls below the desired range, the binder composition may be mixed with water and optionally further additives to form a slurry. When adding the slurry, setting retarders, fluidizers, or other known additives, such as sodium citrate, sodium gluconate, disodium ethylenediaminetetraacetic acid, melamine formaldehyde condensate and naphthalene formaldehyde condensate, lignosulfonate, setting retarders, and fluidizers, may be added to adjust the setting, viscosity, etc.

[0047] The finer the ore and / or binder, the more water is required to achieve sufficient strength. The finer the ore, the more binder is needed.

[0048] It was found that a minimum compressive strength of at least 1400N is advantageous.

[0049] In a first embodiment, the present invention relates to a binder composition, The fineness of the hydraulic binder component is at least D95 < 40 μm, D50 < 12 μm, and D10 < 5 μm (determined by a laser diffraction particle size analyzer), and the Blaine fineness is 6500 to 9000 cm². 2 The content is between / g, the CaO content is >62.5% by weight, the C3S content is >60% by weight, preferably >65% by weight. The hydraulic binder component contains 0.1% to 1% by weight of alkanolamine and / or 0.5% to 10% by weight of gypsum, based on the total weight of the hydraulic binder component.

[0050] In this embodiment, the hydraulic binder is further characterized by having Al2O3 > 4% by weight, Fe2O3 < 3% by weight, SO3 > 3.5% by weight, C3A > 2% by weight (by XRD-Rietveld analysis), and C4AF < 11% by weight (by XRD-Rietveld analysis).

[0051] In embodiments, the binder composition includes, as an additive, one or more from the group consisting of alkanolamines, gypsum, calcium aluminate cement, iron sulfate, calcium chloride and magnesium chloride, any sodium sulfoaluminate, CSH seeds, carboxymethylcellulose, carboxymethyl hydroxyethylcellulose, any vinyl copolymer, sodium citrate, sodium gluconate, disodium salt of ethylenediaminetetraacetic acid, melamine formaldehyde condensate and naphthalene formaldehyde condensate, lignosulfonates, setting retarders, fluidizers, CSH seeds, fluxes, or any mixtures thereof.

[0052] In the embodiment, the binder composition comprises aluminate cement, the aluminate cement being optionally selected from any calcium aluminate cement, any calcium sulfoaluminate cement, or any mixture thereof.

[0053] In the embodiment, the hydraulic binder component contains 2% to 20% by weight of alumina cement, based on the total weight of the hydraulic binder component.

[0054] In some embodiments, the binder composition further comprises a flux, optionally the flux being finely ground limestone and / or dolomite.

[0055] In the embodiment, setting retarders, setting accelerators, and fluidizers may be added to adjust the setting and viscosity.

[0056] A second aspect of the present invention is a method for producing metal ore pellets, A finely ground ore or ore concentrate is mixed with the binder composition described in any of the preceding claims, The obtained mixture is pelletized using a pelletizing disc or drum agglomer, etc.

[0057] In the embodiment, the binder composition is present in an amount of 2% to 12% by weight, preferably 4% to 8% by weight, based on the total weight of the dry pellets. Dry pellets refer to the dry basis of dry iron ore + hydraulic binder + additives.

[0058] In this embodiment, the water content of the ore is 3% to 15% by weight, based on the weight of the ore before mixing.

[0059] In one embodiment, anthracite or other carbon sources are added to the ore before or during pelletizing.

[0060] In this embodiment, the binder composition may be mixed with water to form a slurry.

[0061] In some embodiments, setting retarders, setting accelerators, fluidizers, or other known additives may be added to adjust the setting and viscosity. In some embodiments, anthracite or other carbon sources are added to the ore.

[0062] In the embodiment, the binder composition, either as a dry powder or a slurry mixed with water, is injected or sprayed onto a conveyor belt carrying iron ore or ore concentrate, into an agglomeration device, or injected or sprayed onto iron ore supplied to a pelletizing disc or other agglomeration device.

[0063] In one embodiment, pellets of a consistent shape and size can be formed by injecting or spraying water into a mixture of iron ore and a binder.

[0064] In one embodiment, after pelletizing, the pellets are optionally cured for 2 hours to 2 days in humid air with an rh content exceeding 90% at a temperature exceeding 5°C.

[0065] A third aspect of the present invention relates to metal ore pellets produced by the method described above using the binder composition described above. [Brief explanation of the drawing]

[0066] The present invention will be further described by various embodiments and the following accompanying drawings. [Figure 1] This is a schematic diagram illustrating the process of the present invention in comparison with processes known in related technologies. [Figure 2] This table shows the chemical analysis of examples relating to the present invention and comparative examples. [Figure 3] This table shows the clinker mineral analysis of examples relating to the present invention and comparative examples. [Figure 4] This is the powderiness of examples of hydraulic binders according to the present invention and comparative examples. [Figure 5] This is the compressive strength of the pellets produced using the binder according to the present invention. [Figure 6] This is the compressive strength of the pellets in the comparative example. [Modes for carrying out the invention]

[0067] To prepare the binder composition, a hydraulic binder is selected from any of the following: the fineness of the materials satisfies D95 < 40 μm, D50 < 12 μm, and D10 < 5 μm; the CaO content exceeds 62.5% by weight; and the C3S content is > 60% by weight, preferably > 65% by weight. This hydraulic binder may be selected from CEM I or other cements, such as CEM II, CEM III, calcium aluminate cement, calcium sulfoaluminate cement, or any mixture thereof, as long as the above criteria are met.

[0068] D10 corresponds to the 10th percentile of the particle size volume distribution. That is, 10% of the volume consists of particles smaller than D10, and 90% consists of particles larger than D10. D50 corresponds to the median of the particle size volume distribution, or the 50th percentile. That is, 50% of the volume consists of particles smaller than D50, and 50% consists of particles larger than D50. D95 corresponds to the 95th percentile of the particle size volume distribution. That is, 90% of the volume consists of particles smaller than D95, and 10% consists of particles larger than D95.

[0069] The D10, D50, or D95 of particles are generally determined by laser diffraction. The particle size distribution of various powders is measured using a laser-type Malvern MS2000 particle size analyzer. Measurements are performed in a suitable medium (e.g., an aqueous medium). Particle sizes will range from 0.02 μm to 2 mm. The light source consists of a red helium-neon laser (632 nm) and a blue diode (466 nm). The optical model is the Fraunhofer model, and the calculation matrix is ​​polydisperse type.

[0070] First, measure the background noise with a pump speed of 2000 rpm and a stirring speed of 800 rpm. The noise measurement should be performed for 10 seconds (10s) without ultrasound. Then, confirm that the laser light intensity is equal to at least 80% and that a decreasing exponential curve is obtained for the background noise. If this cannot be confirmed, the cell lens must be cleaned.

[0071] Subsequently, the first measurement is performed on the sample using the following parameters: pump speed 2000 rpm, stirring speed 800 rpm, and an obscuration limit between 10% and 20% without ultrasound. The sample is introduced to slightly increase the obscuration to more than 10%. After the obscuration stabilizes, the measurement is performed with a time between immersion and measurement set to 10 seconds (10 s). The measurement time is 30 seconds (30 s) (30,000 analyzed diffraction images). It should be taken into consideration that some of the powder aggregates may have agglomerated in the obtained granulogram.

[0072] Next, a second measurement is performed with ultrasound (without emptying the tank). The pump speed is set to 2500 rpm, the stirring speed to 1000 rpm, and the ultrasound is emitted at 100% (30 watts). This speed is maintained for 3 minutes, after which the parameters are returned to their initial state. That is, the pump speed is set to 2000 rpm, the stirring speed to 800 rpm, and ultrasound is disabled. After 10 seconds (10 s) (to remove any bubbles that may have formed), the measurement is performed for 30 seconds (30 s) (30,000 analyzed images). This second measurement corresponds to the powder that has been deaggregated by ultrasonic dispersion.

[0073] Each measurement is repeated at least twice to confirm the stability of the results. The apparatus is calibrated before each operation using standard samples (silica, C10, Sifraco) for which the particle size curve is known. All measured values ​​and published ranges shown in the specification correspond to values ​​obtained using ultrasound.

[0074] Preferably, the following criteria are further met: Al2O3 > 4 wt%, Fe2O3 < 3 wt%, SO3 > 3.5 wt%, C3A > 2 wt% (by XRD-Rielbert analysis), C4AF < 11% wt% (by XRD-Rielbert analysis).

[0075] Preferably, the binder composition is a ready-engineered, readily usable composition that mainly contains the aforementioned hydraulic binder and optionally includes additives.

[0076] For this purpose, additives are mixed with the hydraulic binder. The main additives are alkanolamines and / or gypsum and / or ferrous sulfate. When using liquid additives, they can be added during the grinding process of the clinker or other solid hydraulic binder components.

[0077] Based on the total weight of the hydraulic binder components, alkanolamines may be added in amounts of 0.1% to 1% by weight, gypsum (in addition to the source of calcium sulfate as part of the hydraulic binder) in amounts of 0.5% to 10% by weight, and iron sulfate may be added in amounts of 0.1% to 3% by weight. Although any one of these additives alone may provide sufficient strength to the binder after hydration, any mixture of the above additives is also preferable.

[0078] Furthermore, the hydraulic binder may contain aluminate cement, which may be any calcium aluminate cement, any calcium sulfoaluminate cement, or any mixture thereof. In particular, it is present in an amount of 2% to 20% by weight relative to the total amount of the binder.

[0079] Other suitable additives include calcium chloride and magnesium chloride, sodium sulfoaluminate, CSH seeds, carboxymethylcellulose, and vinyl copolymers.

[0080] Although Figure 1 relates to iron ore, the present invention can be successfully applied to other metal ores, such as copper ore.

[0081] As is clear from Figure 1, iron ore is crushed and processed to obtain, for example, an iron ore concentrate. Preferably, the water content in the concentrate is adjusted to 3% to 12% by weight, based on the weight of the ore. The water content should be adapted not only to the fineness of the ore but also to the fineness of the binder composition. The latter may be adapted to the fineness of the ore and the type of iron ore. The finer the ore, the more binder is required.

[0082] Hematite ore can produce pellets with higher compressive strength compared to magnetite ore, which means the latter must be finer and require more binder. Therefore, more water is needed. If the water content of the ore is below this threshold, water may be added. If the water content is above the threshold, the ore may be partially dried to achieve the desired water content.

[0083] The ore concentrate is supplied to a flocculant. The flocculant may be a disc flocculant / pelletizer, or any other suitable, well-known apparatus for processing finely ground raw materials into pellets.

[0084] The binder composition may be added to the iron ore while it is being fed to the pelletizer, or while it is in the pelletizer. To avoid the pellets from solidifying before they are formed in the pelletizer, the binder composition is preferably added immediately before the pelletizing process.

[0085] Water and / or a liquid pelletizing agent may be added to the ore / binder mixture to ensure that pellets of a certain shape and size are formed. The amount of additional water may be calculated taking into account the water content of the ore. A preferred pellet size is 10 mm to 15 mm. Coagulation retarders such as carboxymethyl hydroxyethyl cellulose, coagulation and / or hardening accelerators, fluidizing agents such as sodium citrate, or other known additives may be added to adjust the coagulation, hardening, viscosity, etc.

[0086] The amount of binder added is 2 to 12% by weight of the total weight of the pellets, preferably 4 to 8% by weight of the total weight of the pellets (ore + binder + any additives).

[0087] The pellets are then allowed to harden for 2 to 7 days. During hardening, the temperature should not fall below 5°C, and the relative humidity should be above 90%rh, preferably 100%rh.

[0088] The table in Figure 2 shows the chemical analysis of examples of hydraulic binders according to the present invention and comparative examples. All except GU CEM I meet the criteria related to CaO content.

[0089] Figure 3 shows the analysis of each clinker mineral. As can be seen from the table, all except CEM I 52,5 meet the criteria for C3S content.

[0090] Figure 4 shows the particle distribution and the surface of the brane. While the particle distribution criteria are not met for the non-inventive examples GU CEM I and Type G, the surface criteria are met. CEM I 52,5N does not meet the surface criteria, but of course, it meets the particle distribution criteria.

[0091] Figure 5 shows the compressive strength of pellets produced using the binder composition of the present invention. In all examples, sufficient compressive strength was observed after 2 days and 7 days.

[0092] Figure 6 shows a comparative example. Pellets made using a binder composition that does not meet the standards do not have sufficient compressive strength. Contrary to common knowledge, it is not sufficient to prepare finely ground hydraulic binder for pellets to have sufficient strength. Both the particle size distribution and the surface must meet the standards, even if either the particle size distribution or the surface meets the standards. In addition to the particle size and surface standards, if the CaO content or C3S content is insufficient, the compressive strength will not be sufficiently high.

Claims

1. A binder composition for cold forming of metal ore pellets, It contains a hydraulic binder component and additives. The fineness of the hydraulic binder component is at least D95 < 40 μm, D50 < 12 μm, and D10 < 5 μm (determined by a laser diffraction particle size analyzer), and the Blaine fineness is 6500 to 9000 cm². ２ A binder composition having a concentration between / g, a CaO content of >62.5% by weight, and a C3S content of >60% by weight.

2. The binder composition according to claim 1, comprising 0.1% to 1% by weight of an alkanolamine and / or 0.5% to 10% by weight of gypsum, based on the total weight of the hydraulic binder component.

3. The hydraulic binder is Al ２ 0 ３ >4% by weight, Fe ２ O ３ <3% by weight, SO ３ The binder composition according to claim 1 or 2, further characterized by having >3.5% by weight, C3A > 2% by weight (by XRD-Rielbert analysis), and C4AF < 11% by weight (by XRD-Rielbert analysis).

4. The binder composition according to claim 1, comprising as an additive one or more from the group consisting of alkanolamine, calcium aluminate cement, iron sulfate, calcium chloride and magnesium chloride, sodium sulfoaluminate, CSH seed, carboxymethylcellulose, carboxymethyl hydroxyethylcellulose, vinyl copolymer, sodium citrate, sodium gluconate, disodium salt of ethylenediaminetetraacetic acid, melamine formaldehyde condensate and naphthalene formaldehyde condensate, lignosulfonate, setting retarder, fluidizer, CSH seed, flux, or any mixture thereof.

5. The hydraulic binder component includes aluminate cement, The aluminate cement is arbitrarily selected from any calcium aluminate cement, any calcium sulfoaluminate cement, or any mixture thereof. The binder composition according to any one of claims 1 to 4, wherein the hydraulic binder component comprises 2% to 20% by weight of alumina cement based on the total weight of the hydraulic binder component.

6. The binder composition according to claim 1, further comprising a flux, optionally the flux being finely ground limestone and / or dolomite.

7. The binder composition according to any one of claims 1 to 6, wherein at least one selected from the group consisting of a setting retarder, a setting accelerator, and a fluidizing agent may be added to adjust at least one selected from the group consisting of setting and viscosity.

8. A method for producing metal ore pellets, The finely ground ore or ore concentrate is mixed with the binder composition described in any one of claims 1 to 7. A method comprising pelletizing the obtained mixture using a pelletizing disc or drum agglomer.

9. The method according to claim 8, wherein the binder composition is present in an amount of 2% to 12% by weight based on the total weight of the dry pellets.

10. The method according to claim 8 or 9, wherein the water content of the ore is 3% to 15% by weight, based on the weight of the ore before mixing.

11. The method according to any one of claims 8 to 10, wherein anthracite or other carbon source is added to the ore before or during pelletizing.

12. The method according to any one of claims 8 to 11, further comprising spreading a binder composition as a dry powder or a slurry mixed with water onto a conveyor belt carrying iron ore or ore concentrate, or onto an agglomerating device, or injecting or spraying it onto iron ore supplied to a pelletizing disc or other agglomerating device.

13. The method according to any one of claims 8 to 12, further comprising injecting water into a mixture of iron ore and a binder so that pellets of a consistent shape and size can be formed.

14. The method according to any one of claims 8 to 13, further comprising curing the pellets for 2 to 7 days in a humid atmosphere with a relative humidity (rh) of more than 90% at a temperature of more than 5°C after pelletizing.

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