Composite binder for converter slag-removing agent pellets and preparation method and application thereof

Abstract

The present invention provides a composite binder for converter slag-forming agent pellets and a preparation method and application thereof. The composite binder for converter slag-forming agent pellets of the present invention comprises the following raw materials in parts by weight: 50-60 parts of macromolecular organic matter, 20-30 parts of soda ash and 15-30 parts of dispersant; wherein the macromolecular organic matter comprises polyacrylic acid; and the dispersant comprises silicon micropowder. The composite binder for converter slag-forming agent pellets of the present invention has a high one-time pelletization rate and product strength when used to prepare converter slag-forming agent pellets, and the powder rate is significantly reduced, thereby improving the product quality of converter slag-forming agent pellets, reducing the comprehensive processing cost of the product, and having significant economic and social benefits.

Description

Technical Field

[0001] The invention relates to the technical field of reprocessing and utilizing secondary resources in steelmaking, and in particular to a composite binder for converter slagging agent pellets and a preparation method and application thereof. Background Art

[0002] In recent years, as environmental protection requirements have become increasingly stringent, dust removal and environmental protection facilities have been added to the traditional smelting process, resulting in a large amount of fine-grained dust (<100 mesh). How to effectively and reasonably utilize the dust in the steelmaking process has become an urgent problem to be solved.

[0003] CN108018417A discloses a steelmaking converter slag-forming agent, which is composed of the following components by mass percentage: 35-45% of steelmaking dust, 5-15% of steelmaking sludge, 40-50% of quartz sand, 5-10% of cement, and 0.5-1% of a binder. However, the steelmaking converter slag-forming agent uses traditional inorganic substances such as cement as a binder, and has defects such as low primary balling rate (<80%), low product strength (<100N), and high powder rate (>20%) in the process of producing converter slag-forming agent pellets, thereby affecting the production cost and quality of the product.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a composite binder for converter slag-forming agent pellets and a preparation method and application thereof. The composite binder for converter slag-forming agent pellets has a high one-time pelletizing rate and product strength when used to prepare converter slag-forming agent pellets, and the powder rate is significantly reduced, thereby improving the product quality of converter slag-forming agent pellets and reducing the comprehensive processing cost of the product.

[0006] The invention provides a composite binder for converter slagging agent pellets, comprising the following raw materials in parts by weight: 50-60 parts of high molecular organic matter, 20-30 parts of soda ash and 15-30 parts of dispersant; wherein the high molecular organic matter comprises polyacrylic acid; and the dispersant comprises silicon micropowder.

[0007] Specifically, the particle size of polyacrylic acid is <100 mesh, the molecular weight is >1800, and the viscosity (2% aqueous solution) is ≥0.3 Pa·s; the particle size of soda ash is ≤1 mm, and Na 2 CO 3 Content ≥90%, moisture content ≤0.5%; particle size of silicon micropowder <100 mesh, SiO 2 Content ≥80%, moisture content ≤1%.

[0008] In the present invention, the high molecular organic matter has strong hydrophilic polymerization and a certain viscosity at room temperature, and can effectively bond and aggregate the steelmaking dust in the converter slag-forming agent, thereby producing a higher green ball strength (i.e., initial strength); after drying, the high molecular organic matter undergoes a series of hardening reactions, which further increases its bonding force, thereby improving the converter slag-forming agent pellet strength (i.e., product strength); soda ash is mainly used to adjust the pH value of the binder to ensure stable strength after balling; the dispersant is mainly used to ensure the uniformity of the binder and ensure the uniformity of the binder in the material.

[0009] The present invention also provides a method for preparing the composite binder for converter slag-forming agent pellets, comprising: adding various raw materials by weight into a closed mixer and stirring to obtain the composite binder for converter slag-forming agent pellets.

[0010] The present invention also provides a method for preparing converter slagging agent pellets, comprising the following steps:

[0011] S1: adding a converter slag-removing agent into a mixer, adding the converter slag-removing agent into the mixer, a composite binder for pellets and water, stirring, and pressing into balls after stirring to obtain green balls;

[0012] S2: Dry the green balls to obtain converter slag-forming agent pellets.

[0013] Specifically, in step S1, the amount of composite binder added for converter slag-forming agent pellets is 1.5-2% of the mass of the converter slag-forming agent; water is added until the moisture content of the converter slag-forming agent is 8-10%; the stirring time is ≥3min; the ball pressing conditions are: the pressure of the ball press is not less than 2Mpa, for example, the pressure is 3-5Mpa; the strength of the green balls is >250N.

[0014] In step S2, the raw balls are dried until the moisture content is less than 2%; and the strength of the converter slag-forming agent balls is greater than 1000N.

[0015] The present invention analyzes and studies steelmaking dust (secondary resources) and applies a steelmaking auxiliary material to converter slag agent for recycling. In view of the characteristics of converter slag agent raw materials, the above-mentioned composite binder is specially developed, which not only meets the production technical index requirements, but also improves the one-time ball formation rate and product quality of converter slag agent pellets, wherein the one-time ball formation rate is increased to more than 96%, the green ball strength is increased to more than 250N, the converter slag agent pellet strength is increased to more than 1000N, and the return material (powder rate) in the production process is reduced to less than 10%; at the same time, the production and processing cost is greatly reduced, the comprehensive processing cost per unit product is reduced by more than 10 yuan / ton, the operating environment and labor intensity of operators are significantly improved, and there are significant economic and social benefits. DETAILED DESCRIPTION

[0016] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0017] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The raw materials used in each embodiment are as follows:

[0020] High molecular weight organic polyacrylic acid: particle size <100 mesh, molecular weight >1800, viscosity ≥0.3Pa·s;

[0021] Soda ash: particle size ≤1mm, Na 2 CO 3 Content ≥90%, moisture content ≤0.5%;

[0022] Dispersant silicon powder: particle size <100 mesh, SiO 2 Content ≥80%, moisture content ≤1%.

[0023] Example 1

[0024] 1. Preparation of composite adhesive

[0025] The composite adhesive of this embodiment is composed of the following raw materials in parts by weight: 50 parts of high molecular organic matter, 30 parts of soda ash and 20 parts of dispersant.

[0026] The above raw materials are added into a closed mixer in descending order of weight, and stirred and mixed for 3 minutes to obtain a composite adhesive for use.

[0027] 2. Preparation of converter slag pellets

[0028] After adding the converter slag-forming agent into a mixing mixer and stirring for 1 minute, add the composite binder prepared above and tap water. The amount of the composite binder added is 1.8% of the mass of the converter slag-forming agent. Add tap water to make the moisture content in the converter slag-forming agent 8%. Stir for 3 minutes and then send it into a ball press for ball pressing. The pressure of the ball press is 4MPa to obtain green balls.

[0029] The green balls were baked and dried at 200°C until the moisture content was less than 2%, thereby obtaining converter slagging agent balls. The test results of the first-time ball formation rate, initial strength and product strength are shown in Table 1.

[0030] Example 2

[0031] 1. Preparation of composite adhesive

[0032] The composite adhesive of this embodiment is composed of the following raw materials in parts by weight: 55 parts of high molecular organic matter, 25 parts of soda ash and 20 parts of dispersant.

[0033] The above raw materials are added into a closed mixer in descending order of weight, and stirred and mixed for 3 minutes to obtain a composite adhesive for use.

[0034] 2. Preparation of converter slag pellets

[0035] After adding the converter slag-forming agent into a mixing mixer and stirring for 1 minute, add the composite binder prepared above and tap water. The amount of the composite binder added is 1.5% of the mass of the converter slag-forming agent. Add tap water to make the moisture content in the converter slag-forming agent 9%. Stir for 3 minutes and then send it into a briquette press for briquetting. The pressure of the briquette press is 4MPa to obtain green balls.

[0036] The green balls were baked and dried at 250°C until the moisture content was less than 2%, thereby obtaining converter slagging agent balls. The test results of the first-time ball formation rate, initial strength and product strength are shown in Table 1.

[0037] Example 3

[0038] 1. Preparation of composite adhesive

[0039] The composite adhesive of this embodiment is composed of the following raw materials in parts by weight: 60 parts of high molecular organic matter, 20 parts of soda ash and 20 parts of dispersant.

[0040] The above raw materials are added into a closed mixer in descending order of weight, and stirred and mixed for 3 minutes to obtain a composite adhesive for use.

[0041] 2. Preparation of converter slag pellets

[0042] Add the converter slag-forming agent into a mixing mixer and stir for 1 minute, then add the composite binder prepared above and tap water. The amount of the composite binder added is 2% of the mass of the converter slag-forming agent. Add tap water to make the moisture content in the converter slag-forming agent 10%. Stir for 5 minutes and then send it into a briquette press for briquetting. The pressure of the briquette press is 4MPa to obtain green balls.

[0043] The green balls were baked and dried at 110°C until the moisture content was less than 2% to obtain converter slag-forming agent balls. The test results of the first-time ball formation rate, initial strength and product strength are shown in Table 1.

[0044] Table 1 Test results of converter slag-removing agent pellets in various embodiments

[0045] project One-time ball rate Initial strength (N) Product strength (N) Example 1 96％ 261 1020 Example 2 97％ 275 1040 Example 3 95％ 259 1015

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite binder for converter slagging agent pellets, It is characterized in that The invention comprises the following raw materials in parts by weight: 50-60 parts of high molecular weight organic matter, 20-30 parts of soda ash and 15-30 parts of dispersant; wherein the high molecular weight organic matter is polyacrylic acid, the particle size of polyacrylic acid is less than 100 mesh, the molecular weight is greater than 1800, and the viscosity is greater than or equal to 0.3 Pa·s; the particle size of soda ash is less than or equal to 1 mm, and the Na 2 CO 3 Content ≥90%, moisture content ≤0.5%; dispersant is silica powder, the particle size of silica powder is <100 mesh, SiO 2 Content ≥80%, moisture content ≤1%.

2. The method for preparing the composite binder for converter slagging agent pellets according to claim 1, It is characterized in that include: The raw materials are added into a closed mixer according to weight and stirred to obtain a composite binder for converter slagging agent pellets.

3. A method for preparing converter slagging agent pellets, It is characterized in that The steps include: S1: adding a converter slag-forming agent into a mixer, adding the converter slag-forming agent pelletizing composite binder and water as claimed in claim 1 into the mixer, stirring, and pressing into balls after stirring to obtain green balls; S2: Dry the green balls to obtain converter slag-forming agent pellets.

4. The preparation method according to claim 3, It is characterized in that The added amount of the composite binder for converter slag-forming agent pellets is 1.5-2% of the converter slag-forming agent mass; water is added until the moisture content of the converter slag-forming agent is 8-10%.

5. The preparation method according to claim 3, It is characterized in that In step S1, the stirring time is ≥3 min; the ball pressing molding condition is: the pressure of the ball press is not less than 2 MPa.

6. The preparation method according to claim 3, It is characterized in that In step S2, the drying temperature is 110-250°C, and the drying time is 50-80 minutes; the drying is performed until the moisture content of the raw balls is less than 2%.

7. The preparation method according to claim 3, It is characterized in that The strength of green balls is >250N; the strength of converter slag pellets is >1000N.