Fine iron powder cold-pressed pellet adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of metallurgical pellet adhesives, and particularly relates to a fine iron powder cold-pressed pellet adhesive and a preparation method thereof. The fine iron powder cold-pressed pellet adhesive comprises the following components in parts by mass: 4-12 parts of an inorganic component, 1-5 parts of an organic component and 0.1-1 part of a dispersing agent, wherein the inorganic component is prepared from the following raw materials in parts by mass: 1 to 15 parts of calcium bentonite, 1 to 20 parts of aluminum oxide, 1 to 10 parts of P2O5, 1 to 15 parts of sulphoaluminate cement, 1 to 10 parts of borax and 1 to 8 parts of fly ash; the organic component is prepared from the following raw materials in parts by mass: 1 to 6 parts of polyvinyl alcohol, 5 to 15 parts of water-based phenolic resin and 1 to 10 parts of modified hydroxy propyl cellulose. According to the adhesive disclosed by the invention, the wet strength, the cold strength and the hot strength of the cold-pressed pellets are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical pellet adhesives, and particularly relates to an iron ore concentrate cold-pressed pellet adhesive and a preparation method thereof. Background Art

[0002] With the rapid development of the industrial field, iron ore concentrate, as an important raw material, plays an irreplaceable role in many fields. The output of ore has increased significantly, resulting in large amounts of accumulation and waste of iron resources. Using advanced technology, raw materials are sourced locally, and products are processed and utilized locally, which is economical and technically sound. This technology has great advantages over traditional processes.

[0003] Before iron ore concentrate is fed into the shaft furnace, it is bonded and formed using a binder. The strength of cold-pressed iron ore pellets is a prerequisite for their suitability for shaft furnace smelting. During production, transportation, and use, they are subject to collisions, impacts, and extrusion. Therefore, they must possess sufficiently high physical and metallurgical properties to ensure minimal or no fines are generated during transportation, storage, and smelting, ensuring effective reduction within the furnace to ensure smooth operation.

[0004] Cold-pressed iron ore pellets are prepared from iron ore concentrate through a series of processes, including mixing with a binder, adding water, cold pressing, and drying. Research and development of binders for cold-pressed iron ore pellets for direct reduction applications aims to enhance the binder's performance, thereby improving the physical and metallurgical properties of the pellets. This ensures sufficient wet and cold strength and thermal stability, reducing pellet pulverization during production, transportation, and loading and unloading.

[0005] At present, there are three main types of adhesives for vertical furnaces on the market: inorganic adhesives, organic adhesives and composite adhesives. Bentonite is one of the main components of inorganic adhesives, but calcium-based bentonite is expensive, and sodium-based bentonite will reduce T Fe Organic components completely volatilize during calcination, leaving no residual impurities and maintaining a high iron content in the pellets. However, they easily decompose and become ineffective during high-temperature calcination in a shaft furnace (>1000°C), leading to pellet pulverization or cracking. Composite binders, through the synergy of inorganic and organic components, theoretically offer both high-temperature resistance and room-temperature consolidation strength, resulting in higher dry-ball compressive strength. However, the precise matching of the organic / inorganic ratio leads to high R&D costs, resulting in limited commercial products that fail to meet consumer requirements for binders in terms of wet, cold, and hot strength for cold-pressed pellets.

[0006] The requirements for iron concentrate cold-compacted pellets in terms of wet strength, cold strength, and hot strength are of great significance for their production, transportation, storage, and subsequent metallurgical processes. 1. Wet strength: Wet strength refers to the ability of pellets to maintain their shape without cracking in the presence of a certain amount of moisture. This property is particularly important during the process from the pelletizer to the drying equipment, as the pellets may be subjected to external forces such as extrusion and collision during this period. If the wet strength is insufficient, the pellets are prone to breakage, resulting in an increase in powder, affecting the efficiency of subsequent operations, and potentially causing environmental pollution. 2. Cold strength: Cold strength refers to the mechanical strength of pellets at room temperature after they are completely dried. It reflects the ability of pellets to resist external physical damage (such as the pressure during handling and stacking). Good cold strength can ensure that the pellets are not easily broken during storage and transportation, thereby reducing dust generation, improving transportation efficiency, and ensuring the integrity of the materials before entering the furnace. 3. Hot strength: Hot strength involves the stability of pellets under high-temperature conditions, that is, the ability of pellets to withstand high temperatures without softening or disintegrating when they enter the blast furnace or other smelting devices for reduction reactions. Sufficient hot strength helps to maintain the gas permeability in the furnace, promotes the smooth progress of the reduction reaction, and improves metallurgical efficiency and product quality.

[0007] Therefore, the performance requirements for iron concentrate cold-compacted pellets in these three aspects are directly related to the economic and environmental benefits of pellet production, as well as the quality of the final product. Summary of the Invention

[0008] The object of the present invention is to provide an adhesive for iron concentrate cold-compacted pellets and a preparation method thereof.

[0009] To achieve the above object, the present invention provides the following technical solutions: An adhesive for iron concentrate cold-compacted pellets, comprising the following components in parts by mass: 4 - 12 parts of inorganic components, 1 - 5 parts of organic components, and 0.1 - 1 part of dispersant; wherein, the inorganic components include the following raw materials in parts by mass: 1 - 15 parts of calcium-based bentonite, 1 - 20 parts of aluminum oxide, 1 - 10 parts of P2O5, 1 - 15 parts of sulfoaluminate cement, 1 - 10 parts of borax, and 1 - 8 parts of fly ash; the organic components include the following raw materials in parts by mass: 1 - 6 parts of polyvinyl alcohol, 5 - 15 parts of water-based phenolic resin, and 1 - 10 parts of modified hydroxypropyl cellulose.

[0010] Preferably, it comprises components in the following parts by mass: 6 - 10 parts of inorganic components, 1.5 - 3.5 parts of organic components, and 0.3 - 0.8 part of dispersant; among them, the inorganic components include raw materials in the following parts by mass: 5 - 10 parts of calcium-based bentonite, 1 - 20 parts of aluminum oxide, 1 - 10 parts of P2O5, 1 - 15 parts of sulfoaluminate cement, 2 - 6 parts of borax, and 2 - 5 parts of fly ash; the organic components include raw materials in the following parts by mass: 1 - 4 parts of polyvinyl alcohol, 10 - 15 parts of waterborne phenolic resin, and 5 - 9 parts of modified hydroxypropyl cellulose.

[0011] Preferably, the preparation method of the modified hydroxypropyl cellulose comprises the following steps: Under a nitrogen atmosphere, dissolve hydroxypropyl cellulose, long-chain fatty acid, tosyl chloride, and pyridine in N,N-dimethylacetamide, after heating and reacting, pour the product into an aqueous ether solution, centrifuge, collect the solid, and remove the solvent by rotary evaporation under reduced pressure to obtain the modified hydroxypropyl cellulose.

[0012] Preferably, the mass ratio of the inorganic components to the organic components is (6~10):(1.5~3.5).

[0013] Preferably, the conditions for the heating reaction are to react at 65 - 70 °C for 18 - 20 h.

[0014] Preferably, the long-chain fatty acid includes dodecanoic acid, capric acid, and octanoic acid with a molar ratio of 1:(0.2 - 0.5):(1.3 - 1.6).

[0015] Preferably, 0.4 - 0.5 mol of long-chain fatty acid, 0.8 - 1 mol of tosyl chloride, and 0.8 - 1 mol of pyridine are used per mole of free hydroxyl group in the hydroxypropyl cellulose.

[0016] Preferably, the volume concentration of the aqueous ether solution is 50 - 55%.

[0017] Preferably, the mass ratio of the aluminum oxide, P2O5, and sulfoaluminate cement is (6 - 8):3:(10 - 12).

[0018] As a preferred embodiment, it comprises components in the following parts by mass: 8 parts of inorganic components, 2 parts of organic components, and 0.4 part of dispersant; among them, the inorganic components include raw materials in the following parts by mass: 7 parts of calcium-based bentonite, 7 parts of aluminum oxide, 3 parts of P2O5, 11 parts of sulfoaluminate cement, 5 parts of borax, and 4 parts of fly ash; the organic components include raw materials in the following parts by mass: 3 parts of polyvinyl alcohol, 11 parts of waterborne phenolic resin, and 7 parts of modified hydroxypropyl cellulose.

[0019] Preferably, the dispersant includes sodium lauryl phosphate, polyethylene ether, and nonylphenol polyoxyethylene ether with a mass ratio of 1:(1.3 - 1.5):(0.6 - 0.8).

[0020] As a preferred embodiment, the dispersant comprises sodium lauryl phosphate, polyethylene ether and nonylphenol polyoxyethylene ether in a mass ratio of 1:1.4:0.7.

[0021] Preferably, the dosage of the binder accounts for 3-7% of the mass of the iron concentrate powder.

[0022] The present invention provides a preparation method of the binder for cold-pressed pellets of iron concentrate powder, comprising the following steps: uniformly mixing the raw materials of the inorganic component, the organic component and the dispersant respectively to obtain the binder for cold-pressed pellets of iron concentrate powder.

[0023] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. By carefully selecting the inorganic component, the organic component and the dispersant, and the three producing a synergistic effect, the present invention can improve the performance of the binder for cold-pressed pellets in terms of wet strength, cold strength and hot strength. The enhanced wet strength of the present invention means that the pellets are more stable during the preparation process, reducing the rejection rate caused by cracking or deformation and improving the overall efficiency of the production line. The cold-pressed pellets of the present invention can be applied to more demanding scenarios, such as the construction industry or environmental restoration projects that require higher durability and stability. High-quality products can better meet customer needs, help enterprises establish a better reputation in the market and enhance competitiveness. At the same time, the technological progress of the present invention contributes to the technological upgrading and innovation of the related industries regarding composite binders.

[0024] 2. In the system of the present invention, aluminum oxide, P2O5 and sulfoaluminate cement are compounded in a specific ratio, and a more stable high-temperature phase can be formed under high-temperature action, thereby improving the hot strength of the cold-pressed pellets.

[0025] 3. The dispersant of the present invention can act synergistically with the inorganic component and the organic component to improve the wet pellet drop strength of the cold-pressed pellets.

[0026] 4. The organic component of the present invention has better adhesiveness. By adding modified hydroxypropyl cellulose, the introduced carboxyl group can form a coordination bond with the metal oxide on the surface of the powder, improving the dry pellet compressive strength. Specific Embodiments

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0028] All the raw materials used in the following embodiments of the present invention are commercially available products: Hydroxypropyl cellulose, product number H811266, Xidian Experiment.

[0029] Water-based phenolic resin, Jinan Shanhaitech Chemical Co., Ltd., 2402 water-soluble phenolic resin.

[0030] Sodium lauryl phosphate, Jingzhou Yinjie Chemical Co., Ltd.

[0031] Nonylphenol polyoxyethylene ether: Nonylphenol polyoxyethylene ether NP-10, Jinan Qizhi Chemical Technology Co., Ltd.

[0032] Polyethylene ether: Iso-decyl alcohol polyethylene ether, Guangdong Wengjiang Chemical Reagent Co., Ltd., CAS: 61827-42-7.

[0033] Calcium-based bentonite, Shandong Sishui Shengfeng Bentonite Co., Ltd.

[0034] Sulfoaluminate cement, Tangshan Polar Bear Building Materials Co., Ltd., Quick-hardening sulfoaluminate cement 42.5.

[0035] Fly ash, Lingshou County Shuangshi Mineral Products Processing Factory.

[0036] Polyvinyl alcohol, Jinan Qihang Chemical Technology Co., Ltd., model PVA2488L.

[0037] Example 1 This example provides an iron ore concentrate cold-compacted pellet binder, which includes the following components in parts by mass: 8 parts of inorganic components, 2 parts of organic components, and 0.4 parts of dispersant; the dispersant includes sodium lauryl phosphate, polyethylene ether, and nonylphenol polyoxyethylene ether with a mass ratio of 1:1.4:0.7.

[0038] Among them, the inorganic components include the following raw materials in parts by mass: 7 parts of calcium-based bentonite, 7 parts of aluminum oxide, 3 parts of P2O5, 11 parts of sulfoaluminate cement, 5 parts of borax, and 4 parts of fly ash; the organic components include the following raw materials in parts by mass: 3 parts of polyvinyl alcohol, 11 parts of water-based phenolic resin, and 7 parts of modified hydroxypropyl cellulose.

[0039] The preparation method of modified hydroxypropyl cellulose includes the following steps: Under a nitrogen atmosphere, hydroxypropyl cellulose, long-chain fatty acid, toluenesulfonyl chloride, and pyridine are dissolved in N,N-dimethylacetamide, heated to 68 °C and reacted for 19 h, then the product is poured into a 55% (v / v) aqueous ether solution, centrifuged, the solid is collected, and the solvent is removed by rotary evaporation under reduced pressure to obtain modified hydroxypropyl cellulose.

[0040] The long-chain fatty acid includes dodecanoic acid, decanoic acid, and octanoic acid with a molar ratio of 1:0.3:1.5. 0.5 mol of long-chain fatty acid, 1 mol of toluenesulfonyl chloride, and 1 mol of pyridine are used per mole of free hydroxyl group in hydroxypropyl cellulose.

[0041] A preparation method of an iron concentrate cold-pressed pellet binder, comprising the following steps: passing calcium-based bentonite and fly ash through a 200-mesh sieve, and separately mixing the raw materials of the inorganic component, organic component and dispersant evenly to obtain the iron concentrate cold-pressed pellet binder.

[0042] Example 2 This example provides an iron concentrate cold-pressed pellet binder, comprising the following components in parts by mass: 6 parts of inorganic component, 1.5 parts of organic component and 0.3 part of dispersant; the dispersant comprises sodium lauryl phosphate, polyethylene ether and nonylphenol polyoxyethylene ether with a mass ratio of 1:1.3:0.6.

[0043] Among them, the inorganic component comprises the following raw materials in parts by mass: 5 parts of calcium-based bentonite, 6 parts of aluminum oxide, 3 parts of P2O5, 6 parts of sulfoaluminate cement, 2 parts of borax, 2 parts of fly ash; the organic component comprises the following raw materials in parts by mass: 1 part of polyvinyl alcohol, 10 parts of water-based phenolic resin and 5 parts of modified hydroxypropyl cellulose.

[0044] The preparation method of the modified hydroxypropyl cellulose comprises the following steps: under a nitrogen atmosphere, dissolving hydroxypropyl cellulose, long-chain fatty acid, toluenesulfonyl chloride and pyridine in N,N-dimethylacetamide, heating to 65 °C and reacting for 18 h, then pouring the product into a 50% (v / v) aqueous solution of ether, centrifuging, collecting the solid, and removing the solvent by rotary evaporation under reduced pressure to obtain the modified hydroxypropyl cellulose.

[0045] The long-chain fatty acid comprises dodecanoic acid, capric acid and octanoic acid with a molar ratio of 1:0.2:1.3. 0.4 mol of long-chain fatty acid, 0.8 mol of toluenesulfonyl chloride and 0.8 mol of pyridine are used per mole of free hydroxyl group in hydroxypropyl cellulose.

[0046] A preparation method of an iron concentrate cold-pressed pellet binder, comprising the following steps: passing calcium-based bentonite and fly ash through a 200-mesh sieve, and separately mixing the raw materials of the inorganic component, organic component and dispersant evenly to obtain the iron concentrate cold-pressed pellet binder.

[0047] Example 3 This example provides an iron concentrate cold-pressed pellet binder, comprising the following components in parts by mass: 10 parts of inorganic component, 3.5 parts of organic component and 0.8 part of dispersant; the dispersant comprises sodium lauryl phosphate, polyethylene ether and nonylphenol polyoxyethylene ether with a mass ratio of 1:1.5:0.8.

[0048] Among them, the inorganic component comprises the following raw materials in parts by mass: 10 parts of calcium-based bentonite, 8 parts of aluminum oxide, 3 parts of P2O5, 12 parts of sulfoaluminate cement, 6 parts of borax, 5 parts of fly ash; the organic component comprises the following raw materials in parts by mass: 4 parts of polyvinyl alcohol, 15 parts of water-based phenolic resin and 9 parts of modified hydroxypropyl cellulose.

[0049] The preparation method of modified hydroxypropyl cellulose comprises the following steps: Under a nitrogen atmosphere, hydroxypropyl cellulose, long-chain fatty acid, toluenesulfonyl chloride, and pyridine are dissolved in N,N-dimethylacetamide, and the temperature is raised to 70 °C and reacted for 20 h. Then, the product is poured into a 55% (v / v) aqueous solution of ether, centrifuged, the solid is collected, and the solvent is removed by rotary evaporation under reduced pressure to obtain modified hydroxypropyl cellulose.

[0050] The long-chain fatty acid includes dodecanoic acid, capric acid, and octanoic acid with a molar ratio of 1:0.5:1.6. For each mole of free hydroxyl group in hydroxypropyl cellulose, 0.5 mol of long-chain fatty acid, 1 mol of toluenesulfonyl chloride, and 1 mol of pyridine are used.

[0051] A preparation method of an iron concentrate cold-pressed pellet binder comprises the following steps: Pass calcium-based bentonite and fly ash through a 200-mesh sieve, and uniformly mix the raw materials of the inorganic component, organic component, and dispersant respectively to obtain the iron concentrate cold-pressed pellet binder.

[0052] Example 4 This example provides an iron concentrate cold-pressed pellet binder, which comprises the following components in parts by mass: 8 parts of inorganic component, 2 parts of organic component, and 0.4 part of dispersant; the dispersant comprises sodium lauryl phosphate, polyethylene ether, and nonylphenol polyoxyethylene ether with a mass ratio of 1:1.4:0.7.

[0053] [[ID=!5]]Among them, the inorganic component comprises the following raw materials in parts by mass: 7 parts of calcium-based bentonite, 11 parts of aluminum oxide, 7 parts of P2O5, 3 parts of sulfoaluminate cement, 5 parts of borax, and 4 parts of fly ash; the organic component comprises the following raw materials in parts by mass: 3 parts of polyvinyl alcohol, 11 parts of water-based phenolic resin, and 7 parts of modified hydroxypropyl cellulose.

[0054] The preparation method of modified hydroxypropyl cellulose comprises the following steps: Under a nitrogen atmosphere, hydroxypropyl cellulose, long-chain fatty acid, toluenesulfonyl chloride, and pyridine are dissolved in N,N-dimethylacetamide, and the temperature is raised to 68 °C and reacted for 19 h. Then, the product is poured into a 55% (v / v) aqueous solution of ether, centrifuged, the solid is collected, and the solvent is removed by rotary evaporation under reduced pressure to obtain modified hydroxypropyl cellulose.

[0055] The long-chain fatty acid includes dodecanoic acid, capric acid, and octanoic acid with a molar ratio of 1:0.3:1.5. For each mole of free hydroxyl group in hydroxypropyl cellulose, 0.5 mol of long-chain fatty acid, 1 mol of toluenesulfonyl chloride, and 1 mol of pyridine are used.

[0056] A preparation method of an iron concentrate cold-pressed pellet binder comprises the following steps: Pass calcium-based bentonite and fly ash through a 200-mesh sieve, and uniformly mix the raw materials of the inorganic component, organic component, and dispersant respectively to obtain the iron concentrate cold-pressed pellet binder.

[0057] Example 5 This embodiment provides an iron concentrate cold-pressed pellet binder, which comprises the following components in parts by mass: 8 parts of inorganic components, 2 parts of organic components, and 0.4 part of dispersant; the dispersant comprises sodium lauryl phosphate, polyethylene ether, and nonylphenol polyoxyethylene ether in a mass ratio of 1:1.4:0.7.

[0058] Among them, the inorganic components comprise the following raw materials in parts by mass: 7 parts of calcium-based bentonite, 4 parts of aluminum oxide, 10 parts of P2O5, 7 parts of sulfoaluminate cement, 5 parts of borax, and 4 parts of fly ash; the organic components comprise the following raw materials in parts by mass: 3 parts of polyvinyl alcohol, 11 parts of water-based phenolic resin, and 7 parts of modified hydroxypropyl cellulose.

[0059] The preparation method of the modified hydroxypropyl cellulose comprises the following steps: under a nitrogen atmosphere, hydroxypropyl cellulose, long-chain fatty acid, toluenesulfonyl chloride, and pyridine are dissolved in N,N-dimethylacetamide, and the temperature is raised to 68 °C and reacted for 19 h, then the product is poured into a 55% (v / v) aqueous solution of ether, centrifuged, the solid is collected, and the solvent is removed by rotary evaporation under reduced pressure to obtain the modified hydroxypropyl cellulose.

[0060] The long-chain fatty acid comprises dodecanoic acid, capric acid, and octanoic acid in a molar ratio of 1:0.3:1.5. 0.5 mol of long-chain fatty acid, 1 mol of toluenesulfonyl chloride, and 1 mol of pyridine are used per mole of free hydroxyl group in hydroxypropyl cellulose.

[0061] A preparation method of an iron concentrate cold-pressed pellet binder comprises the following steps: passing calcium-based bentonite and fly ash through a 200-mesh sieve, and uniformly mixing the raw materials of the inorganic components, organic components, and dispersant respectively to obtain the iron concentrate cold-pressed pellet binder.

[0062] Example 6 The difference between this embodiment and Example 1 is: 5 parts of inorganic components and 5 parts of organic components.

[0063] Comparative Example 1 The difference between this comparative example and Example 1 is: the modified hydroxypropyl cellulose is replaced by hydroxypropyl cellulose, product number H811266, Xidian Experiment.

[0064] Comparative Example 2 The difference between this comparative example and Example 1 is: the long-chain fatty acid is replaced by dodecanoic acid.

[0065] Comparative Example 3 The difference between this comparative example and Example 1 is: 7 parts of aluminum oxide, 3 parts of P2O5, and 11 parts of sulfoaluminate cement are replaced by 3 parts of aluminum oxide, 11 parts of P2O5, and 7 parts of sulfoaluminate cement. Comparative Example 4 The difference between this comparative example and Example 1 is: the dispersant is polyethylene ether.

[0066] Comparative Example 5 The difference between this comparative example and Example 1 is that the dispersant includes sodium lauryl phosphate and polyethylene ether with a mass ratio of 1:1.4.

[0067] Comparative Example 6 The difference between this comparative example and Example 1 is that the dispersant includes sodium lauryl phosphate, polyethylene ether and nonylphenol polyoxyethylene ether with a mass ratio of 0.7:1:1.4.

[0068] Comparative Example 7 The difference between this comparative example and Example 1 is that the dispersant is sodium dodecylbenzenesulfonate, stearic acid and Tween with a mass ratio of 1:1.4:0.7.

[0069] Performance Test To 500 g of iron concentrate powder, add 30 g of water, and successively add the inorganic components, organic components and dispersant (a total of 25 g) of the iron concentrate cold-pressed pellet binder prepared in Examples 1-6 and Comparative Examples 1-7, stir evenly, cold-press at 35 MPa, and then dry at 150 °C for 2 h to obtain iron concentrate cold-pressed pellets. Perform performance tests on the iron concentrate cold-pressed pellets according to the conventional test methods in the industry. The results are shown in Table 1.

[0070] Table 1 Performance Test Results As can be seen from Table 1, the binders of Examples 1-6 have significantly improved the performance of cold-pressed pellets in terms of wet strength, cold strength and hot strength. The difference between Examples 4-5 and Example 1 is the change in the ratio of aluminum oxide, P2O5 and sulfoaluminate cement, and it can be found that the hot strength of the cold-pressed pellets decreases. Compared with Example 1, in Example 6, the addition amount of the inorganic component decreases and the addition amount of the organic component increases, and the hot strength of the cold-pressed pellets at 760 °C decreases.

[0071] In Comparative Example 1, hydroxypropyl cellulose was not modified, and the dry ball compressive strength decreased.

[0072] In Comparative Example 2, dodecanoic acid was used as the long-chain alkanoic acid. Compared with Example 1, although the dry ball compressive strength increased slightly, the wet ball drop strength was poor.

[0073] In Comparative Example 3, the ratio of aluminum oxide, P2O5 and sulfoaluminate cement changed, and the hot strength of the cold-pressed pellets decreased.

[0074] In Comparative Examples 4-7, the dispersant compositions were different, and the wet ball drop strength of the cold-pressed pellets decreased.

[0075] 2. Test the performance indexes of the iron concentrate cold-pressed pellets obtained by the binder of Example 1 described above according to the method recorded in Table 2, and the results are shown in Table 2.

[0076] Table 2 Physical and metallurgical property indexes of iron ore concentrate cold-compacted pellets for direct reduction furnace charge As can be seen from Table 2, the properties of the iron ore concentrate cold-compacted pellets prepared with the binder in Example 1 of the present invention meet the usage requirements of the industry.

[0077] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An iron concentrate cold-pressed pellet binder, characterized in that, It comprises components in the following parts by mass: among them, 4 - 12 parts of inorganic components, 1 - 5 parts of organic components and 0.1 - 1 part of dispersant; among them, the inorganic components include raw materials in the following parts by mass: 1 - 15 parts of calcium - based bentonite, 1 - 20 parts of aluminum oxide, 1 - 10 parts of P2O5, 1 - 15 parts of sulfoaluminate cement, 1 - 10 parts of borax, 1 - 8 parts of fly ash; the organic components include raw materials in the following parts by mass: 1 - 6 parts of polyvinyl alcohol, 5 - 15 parts of water - based phenolic resin and 1 - 10 parts of modified hydroxypropyl cellulose.

2. The iron concentrate cold-pressed pellet binder according to claim 1, characterized in that, The mass ratio of the inorganic components to the organic components is (6 - 10):(1.5 - 3.5).

3. The iron concentrate cold-pressed pellet binder according to claim 1, characterized in that, The preparation method of the modified hydroxypropyl cellulose comprises the following steps: under a nitrogen atmosphere, hydroxypropyl cellulose, long - chain fatty acid, toluenesulfonyl chloride and pyridine are dissolved in a solvent, after heating and reacting, the product is poured into an aqueous ether solution, centrifuged, the solid is collected, and the solvent is removed by rotary evaporation under reduced pressure to obtain the modified hydroxypropyl cellulose.

4. The iron concentrate cold-pressed pellet binder according to claim 2, characterized in that, The conditions for the heating reaction are to react at 65 - 70 °C for 18 - 20 h.

5. The iron concentrate cold-pressed pellet binder according to claim 2, wherein The long - chain fatty acid includes dodecanoic acid, capric acid and octanoic acid with a molar ratio of 1:(0.2 - 0.5):(1.3 - 1.6).

6. The iron concentrate cold-pressed pellet binder according to claim 2, wherein For each mole of free hydroxyl groups in hydroxypropyl cellulose, 0.4 - 0.5 mol of long - chain fatty acid, 0.8 - 1 mol of toluenesulfonyl chloride and 0.8 - 1 mol of pyridine are used.

7. The iron concentrate cold-pressed pellet binder according to claim 1, characterized in that, The mass ratio of the aluminum oxide, P2O5 and sulfoaluminate cement is (6 - 8):3:(10 - 12).

8. The iron concentrate cold-compacted pellet binder according to claim 1, characterized in that The dispersant includes sodium lauryl phosphate, polyethylene ether and nonylphenol polyoxyethylene ether with a mass ratio of 1:(1.3 - 1.5):(0.6 - 0.8).

9. The iron concentrate cold-compacted pellet binder according to claim 1, characterized in that, The dosage of the binder accounts for 3 - 7% of the mass of the iron concentrate powder.

10. A preparation method of an iron ore concentrate cold-compacted pellet binder according to any one of claims 1-9, characterized in that, It comprises the following steps: the raw materials of the inorganic components, organic components and dispersant are respectively mixed evenly to obtain the binder for cold - pressed pellets of iron concentrate powder.

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