Biomass carburant as well as preparation method and application thereof

Abstract

The invention provides a biomass carburant and a preparation method and application thereof, and belongs to the field of metallurgy. The method comprises the following steps: mixing biomass carbon and iron powder according to a first set mass ratio to obtain a first mixture; mixing the first mixture with a binder according to a second set mass ratio to obtain a second mixture; the second mixture is pressed into balls, and green balls are obtained; and the green pellets are baked at the set temperature for the set time, and the biomass carburant is obtained. Biomass particles and iron powder are mixed and then pressed into balls, heat treatment is carried out to improve the strength, the prepared biomass carburant is large in density, can be added into molten steel according to a treatment mode of a common alloy material, and is relatively pure in component, so that the problems that common biomass particles are small in density, difficult to add, low in absorptivity, smoke and the like are solved.

Description

Technical Field

[0001] The present application relates to the field of metallurgy technology, and in particular to a biomass recarburizer and a preparation method and application thereof. Background Art

[0002] The steelmaking process requires the addition of numerous fossil carbon recarburizers to provide elemental carbon and heat to the molten steel. However, these recarburizers emit significant amounts of carbon dioxide during their preparation and reaction. With increasing international concern about global carbon dioxide emissions, reducing carbon dioxide emissions from steel production is imperative. Reducing carbon dioxide emissions from fossil recarburizers is a challenge facing all steel companies.

[0003] Replacing fossil carbon with biomass carbon is a possible solution. However, in actual trials, current biomass carbon is often in granular or powder form with a very low density, making it difficult to add to molten steel. This results in low absorption, poor recarburization, high costs, and the generation of large amounts of smoke, which pollutes the environment. Summary of the Invention

[0004] The present application provides a biomass recarburizer and its preparation method and application to solve the following technical problem: how to improve the density and recarburizing effect of the biomass recarburizer used for steel tapping and carbonization.

[0005] In a first aspect, the present invention provides a method for preparing a biomass recarburizer, the method comprising:

[0006] Mixing biomass carbon and iron powder according to a first set mass ratio to obtain a first mixture;

[0007] Mixing the first mixture and the binder according to a second set mass ratio to obtain a second mixture;

[0008] Pressing the second mixed material into balls to obtain green balls; and

[0009] The green pellets are baked at a set temperature and for a set time to obtain a biomass recarburizer.

[0010] Optionally, the first set mass ratio is (0.5-3):1.

[0011] Optionally, the raw material of the biomass carbon is a high-density carbon raw material, and the high-density carbon raw material includes: one or more of wood, straw, crop residues, bark and fruit cores.

[0012] Optionally, in the iron powder, the S content is ≤0.02%, and the P content is ≤0.02%, calculated by mass fraction.

[0013] Optionally, the second set mass ratio is 1:(0.01~0.1).

[0014] Optionally, the binder is bentonite.

[0015] Optionally, the set temperature is 150°C to 250°C, and the set time is 3h to 8h.

[0016] In the second aspect, the present application provides a biomass recarburizer prepared by the method described in any one of the embodiments of the first aspect, wherein the biomass recarburizer meets the following properties: carbon content ≥ 15%, density ≥ 1.3 g / cm 3 , compressive strength ≥500MPa.

[0017] In a third aspect, the present application provides an application of the biomass recarburizer according to the embodiment of the second aspect, the application comprising:

[0018] During the steel tapping process, a deoxidizer is added to the molten steel, and then the biomass recarburizer is added into the ladle along with the steel flow to perform deoxidation and carbon matching during steel tapping.

[0019] Optionally, the carbon absorption rate of the steel tapping carbon blend is ≥70%.

[0020] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0021] The embodiment of the present application provides a method for preparing a biomass recarburizer, which includes: mixing biomass carbon and iron powder according to a first set mass ratio to obtain a first mixture; mixing the first mixture with a binder according to a second set mass ratio to obtain a second mixture; pressing the second mixture into balls to obtain green balls; and baking the green balls at a set temperature and a set time to obtain a biomass recarburizer. First, the biomass carbon is mixed with high-purity iron powder, and the biomass carbon is the main carbon source of the recarburizer. Iron powder acts as a rigid skeleton to improve the strength of the balls, and the iron powder particles can disperse the biomass carbon to avoid uneven density of the balls caused by carbon aggregation; secondly, by adding a binder and high-pressure balling, the biomass carbon and iron powder can be fully mixed and tightly combined, thereby improving the strength and density of the balls; finally, by baking, the moisture in the green balls can be removed and the strength of the balls can be increased. The result is a biomass recarburizer with high carbon content, high density and high strength, which is easy to add to molten steel and can be added to molten steel in the same way as general alloy materials. Its composition is relatively pure, thus solving the problem of low density and low absorption rate of ordinary biomass particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 A schematic flow chart of a method for preparing a biomass recarburizer provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a hard limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numbers within the range. For example, the description of a range from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0027] In addition, in the description of the specification of this application, the terms "including", "comprising", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this article, "at least one" refers to one or more, and "plurality" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple. "Parts" such as parts by weight and parts by mass represent the proportional relationship between the components. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula in the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one-to-one to the proportional numbers in the proportional formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0028] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0029] Figure 1 A schematic flow chart of a method for preparing a biomass recarburizer provided in an embodiment of the present application.

[0030] like Figure 1 As shown, the present application provides a method for preparing a biomass recarburizer, the method comprising:

[0031] S1. Mixing biomass carbon and iron powder according to a first set mass ratio to obtain a first mixture;

[0032] In some embodiments, the raw material of the biomass carbon is a high-density carbon raw material, and the high-density carbon raw material includes: one or more of wood, straw, crop residues, bark and fruit cores.

[0033] In some embodiments, the first set mass ratio is (0.5-3):1.

[0034] Biomass carbon is the main carbon source of the recarburizer. Iron powder acts as a rigid skeleton to improve the strength of the pellets. At the same time, the iron powder particles disperse the biomass carbon to avoid uneven density of the pellets caused by carbon aggregation. The mass ratio of biomass carbon to iron powder is limited to (0.5-3):1. If the mass ratio of biomass carbon to iron powder is <0.5:1, the biomass carbon is insufficient, and the carbon content of the finished recarburizer is too low, which affects the substitution effect and cannot meet the steelmaking recarburization requirements; if the mass ratio of biomass carbon to iron powder is >3:1, there is too little iron powder, the strength of the pellets decreases, and the dispersing effect of the iron powder fails, and the density decreases. Exemplarily, the mass ratio of biomass carbon to iron powder can be 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc.

[0035] In some embodiments, in the iron powder, the S content is ≤0.02%, and the P content is ≤0.02%, calculated by mass fraction.

[0036] The S content in iron powder is limited to ≤0.02%, and the P content is limited to ≤0.02%. S and P are brittle elements in steel. Exceeding the limit can seriously contaminate the molten steel and significantly reduce the toughness of the steel. For example, the S content in iron powder can be 0.005%, 0.008%, 0.01%, 0.015%, 0.02%, etc., and the P content can be 0.005%, 0.008%, 0.01%, 0.015%, 0.02%, etc.

[0037] S2. Mixing the first mixture and the binder according to a second set mass ratio to obtain a second mixture;

[0038] The role of the binder is to allow the biomass carbon and iron powder to be fully mixed and tightly combined, preparing for the next step of pelletizing and improving the strength and density of the pellets.

[0039] In some embodiments, the binder is bentonite.

[0040] Bentonite absorbs water and expands to form a gel network, which encapsulates the biomass carbon and iron powder, increasing the strength of the pellets. At the same time, bentonite can fill the gaps between particles, reducing the porosity of the pellets and increasing the density.

[0041] In some embodiments, the second set mass ratio is 1:(0.01-0.1).

[0042] The mass ratio of the first mixture to the binder is limited to 1:(0.01~0.1), so that the biomass carbon and iron powder can be fully mixed and tightly combined. If the mass ratio of the first mixture to the binder is <1:0.01, the bonding is insufficient and the pressed balls are fragile. If the mass ratio of the first mixture to the binder is >1:0.1, the excess bentonite blocks the pores, hinders the penetration of molten steel, and reduces the carbon absorption rate. Exemplarily, the mass ratio of the first mixture to the binder can be 1:0.01, 1:0.02, 1:0.04, 1:0.06, 1:0.08, 1:0.09, 1:0.1, etc.

[0043] S3, pressing the second mixture into balls to obtain green balls; and

[0044] In some embodiments, the pelletizing is performed using a continuous pelletizing machine.

[0045] It should be noted that the continuous briquetting machine is a mechanical equipment that uses high-pressure extrusion to shape powdered or granular materials into balls or blocks. It is widely used in metallurgy, chemical industry, building materials, environmental protection and other fields. It is especially suitable for the preparation of carbonizers, mineral powder pellets, biomass fuels, desulfurizers and other scenarios that require high-density and high-strength molding.

[0046] S4. Baking the green pellets at a set temperature and for a set time to obtain a biomass recarburizer.

[0047] In some embodiments, the set temperature is 150° C. to 250° C., and the set time is 3 hours to 8 hours.

[0048] The baking temperature is limited to 150℃~250℃ and the time is 3h~8h, which can remove moisture from the raw balls and thus increase the strength of the balls. If the baking temperature is less than 150℃ and the time is less than 3h, the time is too short and the moisture will not be completely discharged, resulting in insufficient strength. If the baking temperature is greater than 250℃ and the time is greater than 8h, the strength will be reduced and energy will be wasted. For example, the baking temperature can be 150℃, 170℃, 190℃, 200℃, 220℃, 240℃, 250℃, etc., and the time can be 3h, 4h, 5h, 6h, 7h, 8h, etc.

[0049] Based on a general inventive concept, the present application provides a biomass recarburizer prepared by the method described in any one of the above embodiments, wherein the biomass recarburizer meets the following properties: carbon content ≥ 15%, density ≥ 1.3 g / cm 3 , compressive strength ≥500MPa.

[0050] In the embodiment of the present application, high-density biomass carbon and high-purity iron powder are selected, and after mixing, a binder is added to form a pellet under high pressure, and then heat-treated to obtain a biomass recarburizer with high carbon content, high density, and high strength. It is easy to add to molten steel, significantly improves the addition efficiency, reduces costs, avoids smoke, and replaces fossil recarburizers to significantly reduce carbon dioxide emissions. For example, the carbon content of the biomass recarburizer can be 15%, 20%, 25%, 30%, 35%, 40%, 45%, etc., and the density can be 1.3g / cm 3 , 1.5g / cm 3 , 1.6g / cm 3 , 1.8g / cm 3 , 2.0g / cm 3 , 2.2g / cm 3 etc., and the compressive strength can be 500MPa, 600MPa, 700MPa, 800MPa, 900MPa, etc.

[0051] The biomass recarburizer is realized based on the preparation method of the above-mentioned biomass recarburizer. The specific steps of the preparation method of the biomass recarburizer can refer to the above-mentioned embodiment. Since the biomass recarburizer adopts part or all of the technical solutions of the above-mentioned embodiment, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiment, which will not be repeated here.

[0052] Based on a general inventive concept, the present application provides an application of the biomass recarburizer described in the above embodiment, the application comprising:

[0053] During the steel tapping process, a deoxidizer is added to the molten steel, and then the biomass recarburizer is added into the ladle along with the steel flow to perform deoxidation and carbon matching during steel tapping.

[0054] In some embodiments, the carbon absorption rate of the steel tapping carbon blend is ≥70%.

[0055] In summary, the biomass recarburizer and its preparation method and application provided in the embodiments of the present application have the following advantages:

[0056] (1) Raw material selection and ratio advantages: Wood, straw, crop residues, bark and fruit cores are selected as biomass carbon raw materials. These raw materials are widely available and renewable, which helps to reduce production costs and reduce environmental impact. At the same time, the S and P contents in the iron powder are strictly controlled at ≤0.02%, avoiding the contamination of brittle elements in the steel and ensuring the toughness of the steel. In addition, the mass ratio of biomass carbon to iron powder is between (0.5-3):1, ensuring a high carbon content (≥15%) and sufficient ball strength (≥500MPa) of the recarburizer, while maintaining the uniformity of density (≥1.3g / cm 3 ).

[0057] (2) Advantages of the preparation process: Bentonite is used as a binder, which absorbs water and expands to form a gel network, effectively wrapping the biomass carbon and iron powder, thereby improving the strength and density of the pellets. At the same time, the use of a continuous pelletizing machine for pelletizing achieves efficient and automated production, improving production efficiency and product quality. In addition, the baking temperature is between 150°C and 250°C, and the baking time is 3h to 8h, which not only removes moisture from the raw balls, but also maintains the strength of the pellets, thus avoiding energy waste.

[0058] (3) Product performance advantages: The carbon content of biomass recarburizer is ≥15%, which meets the demand for carbonization in steelmaking. At the same time, the density is ≥1.3g / cm 3 , compressive strength ≥ 500MPa, ensuring the stability and efficiency of the recarburizer when added to molten steel. In addition, it can replace fossil recarburizers, significantly reducing carbon dioxide emissions, in line with the green and low-carbon production concept.

[0059] (4) Application Advantages: During the steel-tapping process, the biomass recarburizer is added to the ladle along with the steel flow, achieving an integrated operation of deoxidation and carbonization during steel-tapping, thereby improving steelmaking efficiency. At the same time, the carbon absorption rate of carbonization during steel-tapping is ≥70%, reducing carbon loss and improving energy efficiency.

[0060] (5) Comprehensive economic and environmental benefits: Biomass raw materials are inexpensive and the preparation process is efficient, which reduces production costs. Replacing fossil fuels reduces greenhouse gas emissions and meets the requirements of sustainable development. Utilizing biomass resources such as agricultural waste enables resource recycling and promotes the development of a circular economy.

[0061] Therefore, the embodiment of the present application achieves a breakthrough in the high carbon, high density and high strength performance of the recarburizer through the synergistic ratio of high-density biomass carbon and high-purity iron powder, bentonite bonding reinforcement and baking process.

[0062] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods in the following examples where specific conditions are not specified are generally measured according to industry standards. If there are no corresponding industry standards, then the methods are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0063] This embodiment provides a method for preparing a biomass recarburizer, which may specifically include the following steps:

[0064] 1. Raw material preparation: Select biomass carbon prepared from high-density raw materials such as fruit shells and wood, and iron powder with S content ≤ 0.02% and P content ≤ 0.02%.

[0065] 2. Prepare biomass carbon and iron powder into two silos respectively.

[0066] 3. According to the mass ratio of biomass carbon to iron powder of 0.5 to 3:1, the biomass carbon and iron powder are placed in a mixing belt, and then the mixing belt pours the materials into the mixing bin to obtain a first mixture.

[0067] 4. Mechanical stirring is performed in the mixing bin to further mix the biomass carbon and the iron powder, and bentonite and an appropriate amount of deionized water are added according to the mass ratio of the first mixture to bentonite being 1: (0.01-0.1) to obtain a second mixture.

[0068] 5. Add the second mixed material to a continuous briquetting machine and press the pellets to obtain green pellets. Place the pressed green pellets in a heat treatment furnace and bake them at a temperature of 150°C to 250°C for 3 to 8 hours to obtain a biomass recarburizer. Specific parameters for the preparation method of the biomass recarburizer are shown in Table 1.

[0069] Table 1 Specific parameters of the preparation method of biomass recarburizer

[0070]

[0071] The performance of the biomass recarburizers obtained in Examples 1 to 3 and Comparative Examples 1 to 3 was measured, and the results are shown in Table 2.

[0072] Table 2 Performance of biomass recarburizers in Examples 1 to 3 and Comparative Examples 1 to 3

[0073] Group Carbon raiser fullerene carbon content, % <![CDATA[Increment agent ball density, g / cm 3 > Compressive strength of carburizer balls, MPa Example 1 15 2.2 750 Example 2 32 1.7 630 Example 3 40 1.3 500 Comparative Example 1 13 2.5 800 Comparative Example 2 40 1.2 440 Comparative Example 3 42 1.0 370

[0074] Based on the above examples, a biomass recarburizer application is also provided. The application includes adding a deoxidizer to molten steel during the tapping process, and then adding the biomass recarburizer along with the steel flow into the ladle to deoxidize and carbonize the steel during tapping. Specific parameters for the biomass recarburizer application process are shown in Table 3.

[0075] Table 3 Specific parameters of the application process of biomass recarburizer

[0076]

[0077]

[0078] Due to its low density, traditional biomass carbon is partially removed by the dust removal system during the ladle feeding process. After addition, it floats on the slag surface, preventing adequate mixing even with strong bottom-blowing and stirring, resulting in a very low carbon absorption rate. The novel biomass carbon provided in this embodiment has a significantly higher density than traditional biomass carbon. During the steel tapping process, a deoxidizer is first added for deoxidation, and then the novel biomass recarburizer is added to the ladle along with the steel flow. The added material is essentially dissolved in the molten steel, significantly increasing the carbon absorption rate.

[0079] In addition, one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0080] In the embodiment of the present application, the obtained biomass recarburizer meets the following properties: carbon content ≥ 15%, density ≥ 1.3g / cm 3 , compressive strength ≥500MPa.

[0081] In the embodiment of the present application, by mixing biomass particles with iron powder, pressing them into balls, and performing heat treatment to increase the strength, the prepared biomass recarburizer has a high density and can be added to molten steel in the same manner as general alloy materials. Its composition is relatively pure, thus solving the problems of ordinary biomass particles with low density, difficulty in adding, low absorption rate, and smoke.

[0082] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for preparing a biomass recarburizer, comprising: Mixing biomass carbon and iron powder according to a first set mass ratio to obtain a first mixture; Mixing the first mixture and the binder according to a second set mass ratio to obtain a second mixture; Pressing the second mixture into balls to obtain green balls; as well as The green pellets are baked at a set temperature and for a set time to obtain a biomass recarburizer.

2. The method according to claim 1, characterized in that The first set mass ratio is (0.5-3):

1.

3. The method according to claim 1, characterized in that The raw material of the biomass carbon is a high-density carbon raw material, and the high-density carbon raw material includes: one or more of wood, straw, crop residues, bark and fruit core.

4. The method according to claim 1, wherein Calculated by mass fraction, in the iron powder, the S content is ≤0.02%, and the P content is ≤0.02%.

5. The method according to claim 1, wherein The second set mass ratio is 1:(0.01-0.1).

6. The method according to claim 1, wherein The binder is bentonite.

7. The method according to claim 1, characterized in that The set temperature is 150° C. to 250° C., and the set time is 3 hours to 8 hours.

8. A biomass recarburizer prepared by the method according to any one of claims 1 to 7, wherein the biomass recarburizer meets the following properties: carbon content ≥ 15%, density ≥ 1.3 g / cm 3 , compressive strength ≥500MPa.

9. An application of the biomass recarburizer according to claim 8, comprising: During the steel tapping process, a deoxidizer is added to the molten steel, and then the biomass recarburizer is added into the ladle along with the steel flow to perform deoxidation and carbon matching during steel tapping.

10. The use according to claim 9, characterized in that The carbon absorption rate of the steel tapping carbon mixture is ≥70%.

Images