Manganese-based composite binder for in-situ catalytic denitration of iron ore oxidized pellets as well as preparation method and application of manganese-based composite binder
In-situ catalytic denitrification using manganese-based composite binders during the production of iron ore oxide pellets solves the problems of high equipment investment, high energy consumption, and complex systems in existing technologies. It achieves low-cost and high-efficiency nitrogen oxide control and makes resource-efficient use of manganese solid waste.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANGZHOU TAIFU SPECIAL MATERIAL CO LTD
- Filing Date
- 2026-01-29
- Publication Date
- 2026-04-21
AI Technical Summary
In the existing iron ore oxide pellet production process, the end-of-pipe denitrification process has problems such as large equipment investment, high operating energy consumption, complex system maintenance, and large catalyst consumption, making it difficult to achieve economical, efficient and sustainable nitrogen oxide control.
A manganese-based composite binder is used to combine manganese-containing solid waste with an organic binder to prepare a manganese-based composite binder with a particle size of less than 0.074 mm. In the iron ore oxide pellet production process, the manganese element in the roasting process catalyzes the decomposition of nitrogen oxides in the flue gas, thereby achieving in-situ denitrification.
It achieves low-cost, in-situ catalytic denitrification, reduces the concentration of nitrogen oxides in roasting flue gas, and makes resource-efficient use of manganese solid waste, simplifying equipment requirements and reducing operational complexity and operating costs.
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal smelting technology, and in particular to a manganese-based composite binder for in-situ catalytic denitrification of iron ore oxide pellets, its preparation method, and its application. Background Technology
[0002] During the production of iron ore oxide pellets, a large amount of nitrogen oxides are generated during the roasting stage due to fuel combustion and the reaction of nitrogen with oxygen in a high-temperature atmosphere. To meet environmental protection requirements, existing technologies generally adopt end-of-pipe denitrification processes such as selective catalytic reduction and selective non-catalytic reduction. However, these methods have problems such as large equipment investment, high operating energy consumption, complex system maintenance, and large catalyst consumption. This not only increases the pollution control costs of enterprises but also brings additional burdens of equipment operation and waste catalyst disposal, making it difficult to achieve economical, efficient, and sustainable nitrogen oxide control in the pellet production process. Summary of the Invention
[0003] The purpose of this invention is to provide a manganese-based composite binder, its preparation method, and its application for in-situ catalytic denitrification of iron ore oxide pellets. This invention enables the resource utilization of manganese-containing solid waste as a pellet binder and achieves low-cost in-situ catalytic denitrification during the roasting process.
[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions for the manganese-based composite binder, its preparation method, and its application in in-situ catalytic denitrification of iron ore oxide pellets:
[0005] A manganese-based composite binder for in-situ catalytic denitrification of iron ore oxide pellets comprises the following components by mass percentage: 50%~70% manganese-containing solid waste and 30%~50% organic binder, wherein, based on the total mass of the manganese-based composite binder, the mass content of manganese element is not less than 10%.
[0006] Preferably, the manganese-containing solid waste is at least one of electrolytic manganese slag, manganese ore tailings, manganese alloy smelting slag, or waste manganese battery slag.
[0007] Preferably, the organic binder is at least one of humic acid, alginate, chitosan, or sodium citrate.
[0008] A method for preparing a manganese-based composite binder includes the following steps: mixing manganese-containing solid waste and an organic binder, then drying and grinding the mixture to ensure that the proportion of particles smaller than 0.074 mm is not less than 90%, thereby obtaining the manganese-based composite binder.
[0009] Preferably, the drying temperature is not higher than 90℃.
[0010] An in-situ catalytic denitration method for iron ore oxide pellets, using a manganese-based composite binder prepared by the above-mentioned method, the in-situ catalytic denitration method comprising the following steps:
[0011] (1) Iron concentrate is mixed with manganese-based composite binder to obtain a mixture, wherein the amount of manganese-based composite binder added is 2% to 6% of the mass of iron concentrate;
[0012] (2) The mixture is pelletized to obtain green pellets;
[0013] (3) The green pellets are roasted in an oxidizing atmosphere at 1200℃~1350℃ to obtain iron ore oxide pellets; during the roasting process, the manganese element in the manganese-based composite binder catalyzes the decomposition of nitrogen oxides in the flue gas on the surface and pores of the pellets, thereby achieving in-situ denitrification.
[0014] Preferably, the iron concentrate has a particle size of less than 0.074 mm accounting for no less than 90%, and a specific surface area of 1500-2500 cm² / g.
[0015] Preferably, the iron grade of the iron concentrate is not less than 63%.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0017] 1. This invention combines manganese-containing solid waste with an organic binder to design a functional material that combines excellent bonding performance with high-temperature catalytic activity. The organic components of this composite system not only act as binders and shapers during the pelletizing stage, but also decompose during subsequent high-temperature roasting, forming abundant microporous channels in situ within and on the surface of the pellets. This allows the manganese components derived from the solid waste to be highly dispersed and stably stored in the porous structure, transforming into manganese oxides with numerous active sites. Thus, in an oxidizing roasting atmosphere, it can efficiently catalyze the decomposition of nitrogen oxides in flue gas, achieving a fundamental breakthrough in low-cost, in-situ denitrification at the source of pellet production.
[0018] 2. In this invention, the proportion of particles smaller than 0.074 mm in the manganese-based composite binder is not less than 90%, which allows the active components to be fully exposed and in contact with the flue gas. The manganese active components are highly dispersed and enriched on the surface and pore interface of the pellets during the pelleting process. Combined with the pore-forming effect of the organic components during roasting, a huge active specific surface area is constructed, which allows the manganese oxides to be fully exposed in the roasting flue gas. This enables efficient catalysis of nitrogen oxide decomposition under oxidizing high-temperature environment, achieving a fundamental transformation of high-exposure and effective catalysis.
[0019] 3. This invention can directly utilize existing pellet production lines without the need for additional expensive and complex end-of-pipe denitrification equipment, ensuring smooth process integration and simple operation. Simultaneously, it achieves resource utilization of manganese-containing solid waste. Detailed Implementation
[0020] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.
[0021] Example 1
[0022] A method for preparing a manganese-based composite binder includes the following steps: taking 70% electrolytic manganese slag and 30% humic acid, mixing them evenly according to the mass percentage, drying them at 80℃, and then grinding them until the proportion of particles smaller than 0.074mm is 95%, and the mass content of manganese in the manganese-based composite binder is measured to be 14%.
[0023] An in-situ catalytic denitrification method for iron ore oxide pellets includes the following steps:
[0024] (1) Iron concentrate is mixed with manganese-based composite binder to obtain a mixture; wherein the iron concentrate is magnetite concentrate, with a particle size of less than 0.074 mm accounting for 93%, a specific surface area of 1697 cm² / g, and an iron grade of 64.8%; the amount of manganese-based composite binder added is 3% of the mass of iron concentrate;
[0025] (2) The mixture is pelletized to obtain green pellets. The drop strength of the green pellets is 3.9 times / (0.5m•pellet).
[0026] (3) The green pellets were roasted in an oxidizing atmosphere at 1270℃ to obtain iron ore oxide pellets. During the roasting process, the manganese element in the manganese-based composite binder catalyzes the decomposition of nitrogen oxides in the flue gas on the surface and pores of the pellets, thereby achieving in-situ denitrification. The concentration of nitrogen oxides in the roasting flue gas was measured to be 601 mg / m³.
[0027] Example 2
[0028] A method for preparing a manganese-based composite binder includes the following steps: taking 50% manganese ore tailings and 50% alginate, mixing them evenly according to the mass percentage, drying them at 80℃, and then grinding them until the proportion of particles smaller than 0.074mm is 95%, and the mass content of manganese in the manganese-based composite binder is measured to be 10%.
[0029] An in-situ catalytic denitrification method for iron ore oxide pellets includes the following steps:
[0030] (1) Iron concentrate is mixed with manganese-based composite binder to obtain a mixture; wherein the iron concentrate is magnetite concentrate, with a particle size of less than 0.074 mm accounting for 93%, a specific surface area of 1697 cm² / g, and an iron grade of 64.8%; the amount of manganese-based composite binder added is 6% of the mass of iron concentrate;
[0031] (2) The mixture is pelletized to obtain green pellets. The drop strength of the green pellets is 4.3 times / (0.5m•pellet).
[0032] (3) The green pellets were roasted in an oxidizing atmosphere at 1350℃ to obtain iron ore oxide pellets. During the roasting process, the manganese element in the manganese-based composite binder catalyzes the decomposition of nitrogen oxides in the flue gas on the surface and pores of the pellets, thereby achieving in-situ denitrification. The concentration of nitrogen oxides in the roasting flue gas was measured to be 630 mg / m³.
[0033] Example 3
[0034] A method for preparing a manganese-based composite binder includes the following steps: taking 60% manganese alloy smelting slag and 40% chitosan, mixing them evenly according to the mass percentage, drying them at 85°C, and then grinding them until the proportion of particles smaller than 0.074 mm is 91%, and the mass content of manganese in the manganese-based composite binder is measured to be 12%.
[0035] An in-situ catalytic denitrification method for iron ore oxide pellets includes the following steps:
[0036] (1) Iron concentrate and manganese-based composite binder are mixed to obtain a mixture; wherein the iron concentrate is magnetite concentrate, with a particle size of less than 0.074 mm accounting for 93%, a specific surface area of 1697 cm² / g, and an iron grade of 64.8%; the amount of manganese-based composite binder added is 2% of the mass of iron concentrate;
[0037] (2) The mixture is pelletized to obtain green pellets. The drop strength of the green pellets is 3.6 times / (0.5m•pellet).
[0038] (3) The green pellets were roasted in an oxidizing atmosphere at 1270℃ to obtain iron ore oxide pellets. During the roasting process, the manganese element in the manganese-based composite binder catalyzes the decomposition of nitrogen oxides in the flue gas on the surface and pores of the pellets, thereby achieving in-situ denitrification. The concentration of nitrogen oxides in the roasting flue gas was measured to be 625 mg / m³.
[0039] Comparative Example 1
[0040] Magnetite concentrate was mixed with humic acid at a ratio of 3% to the magnetite concentrate to obtain a mixture. The humic acid was dried at 80℃ and then ground, with 95% of the particles having a size smaller than 0.074mm. The magnetite concentrate had a particle size smaller than 0.074mm of 93%, a specific surface area of 1697 cm² / g, and an iron content of 64.8%.
[0041] The mixture is then pelletized to obtain green pellets with a drop strength of 4.5 times / (0.5m•pelle); the green pellets are then calcined in an oxidizing atmosphere at 1270℃, with a nitrogen oxide concentration of 785mg / m³ in the calcination flue gas.
[0042] Comparative Example 2
[0043] Magnetite concentrate was mixed with a manganese-based composite binder at a ratio of 3% to the magnetite concentrate to obtain a mixture. The manganese-based composite binder consisted of 90% humic acid and 10% electrolytic manganese slag. After drying at 80°C, the mixture was ground, resulting in a particle size of 97% smaller than 0.074 mm and a manganese content of 2%. The magnetite concentrate had a particle size of 93% smaller than 0.074 mm, a specific surface area of 1697 cm² / g, and an iron content of 64.8%.
[0044] The mixture is then pelletized to obtain green pellets with a drop strength of 4.3 times / (0.5m•pelle); the green pellets are then calcined in an oxidizing atmosphere at 1270℃, with a nitrogen oxide concentration of 752mg / m³ in the calcination flue gas.
[0045] Comparative Example 3
[0046] Magnetite concentrate was mixed with a manganese-based composite binder at a ratio of 3% to the magnetite concentrate to obtain a mixture. The manganese-based composite binder consisted of 50% humic acid and 50% electrolytic manganese slag, which were dried at 80°C and then ground. The mixture had 70% particles smaller than 0.074 mm and a manganese content of 10%. The magnetite concentrate had 93% particles smaller than 0.074 mm, a specific surface area of 1697 cm² / g, and an iron content of 64.8%.
[0047] The mixture is then pelletized to obtain green pellets with a drop strength of 2.8 times / (0.5m•pelle); the green pellets are then roasted in an oxidizing atmosphere at 1270℃, with a nitrogen oxide concentration of 688mg / m³ in the roasting flue gas.
[0048] Comparative Example 4
[0049] Magnetite concentrate was mixed with a manganese-based composite binder at a ratio of 3% to the magnetite concentrate to obtain a mixture. The manganese-based composite binder comprised 40% humic acid and 60% electrolytic manganese slag. After drying at 150℃, the mixture was ground, resulting in a particle size distribution of 91% smaller than 0.074mm and a manganese content of 12%. The magnetite concentrate had a particle size distribution of 93% smaller than 0.074mm, a specific surface area of 1697 cm² / g, and an iron content of 64.8%.
[0050] The mixture is then pelletized to obtain green pellets with a drop strength of 2.3 times / (0.5m•pelle); the green pellets are then calcined in an oxidizing atmosphere at 1270℃, with a nitrogen oxide concentration of 631mg / m³ in the calcination flue gas.
[0051] In summary, the manganese-based composite binder and its application method in Examples 1-3 of this invention have significant advantages. Compared to comparative examples without manganese components or with only low-content manganese components, this invention, by combining a specific proportion of manganese-containing solid waste with an organic binder and controlling its particle size, forms a highly efficient catalytic system in an iron concentrate matrix. This significantly reduces the concentration of nitrogen oxides in the roasting flue gas while ensuring the strength of the green pellets. This verifies that this invention not only achieves high-value resource utilization of manganese-containing solid waste, but more importantly, it achieves highly efficient in-situ catalytic removal of nitrogen oxides at the source of pellet roasting.
Claims
1. A manganese-based composite binder for in-situ catalytic denitrification of iron ore oxide pellets, characterized in that, The components include the following percentages by mass: 50% to 70% manganese-containing solid waste and 30% to 50% organic binder, wherein the manganese content is not less than 10% based on the total mass of the manganese-based composite binder.
2. The manganese-based composite adhesive according to claim 1, characterized in that: The manganese-containing solid waste is at least one of electrolytic manganese slag, manganese ore tailings, manganese alloy smelting slag, or waste manganese battery slag.
3. The manganese-based composite adhesive according to claim 1, characterized in that: The organic binder is at least one of humic acid, alginate, chitosan, or sodium citrate.
4. A method for preparing a manganese-based composite adhesive as described in any one of claims 1-3, characterized in that, Includes the following steps: Manganese-containing solid waste and organic binder are mixed, then dried and ground to ensure that at least 90% of the particles are smaller than 0.074 mm, resulting in a manganese-based composite binder.
5. The method for preparing the manganese-based composite adhesive according to claim 4, characterized in that: The drying temperature should not exceed 90℃.
6. An in-situ catalytic denitrification method for iron ore oxide pellets, characterized in that, The in-situ catalytic denitration method using the manganese-based composite binder prepared by the preparation method described in claim 4 or 5 includes the following steps: (1) Iron concentrate is mixed with manganese-based composite binder to obtain a mixture, wherein the amount of manganese-based composite binder added is 2% to 6% of the mass of iron concentrate; (2) The mixture is pelletized to obtain green pellets; (3) The green pellets are roasted in an oxidizing atmosphere at 1200℃~1350℃ to obtain iron ore oxide pellets; during the roasting process, the manganese element in the manganese-based composite binder catalyzes the decomposition of nitrogen oxides in the flue gas on the surface and pores of the pellets to achieve in-situ denitrification.
7. The in-situ catalytic denitrification method for iron ore oxide pellets according to claim 6, characterized in that: The iron concentrate has a particle size of less than 0.074 mm accounting for no less than 90%, and a specific surface area of 1500-2500 cm² / g.
8. The in-situ catalytic denitrification method for iron ore oxide pellets according to claim 6, characterized in that: The iron grade of the iron concentrate is not less than 63%.