A slag-making agent for semi-steel steelmaking production and its preparation method

Abstract

The present invention discloses a slag-forming agent for semi-steel steelmaking production and a preparation method thereof. The slag-forming agent includes: steelmaking dedusting ash, ferromanganese slag, waste tundish dry material, quartz sand and binder. Adding ferromanganese slag and waste tundish dry material to the slag-forming agent of the present invention has no impact on the original process and does not produce a large amount of harmful substances. It can replace steelmaking dedusting ash and steelmaking sludge to produce slag-forming agent, solve the problems of waste ferromanganese slag generated during the development of titanium resources and waste continuous casting tundishes generated during the continuous casting production of steelmaking, realize "turning waste into treasure", and the reduced amount of steelmaking dedusting ash and sludge can be added as raw materials for sinter.

Description

Technical Field

[0001] The invention relates to the technical field of iron and steel metallurgy, and in particular to a slag-forming agent used in semi-steel steelmaking production and a preparation method thereof. Background Art

[0002] Steel mills use spray vanadium extraction, converter vanadium extraction and other processes to extract vanadium, titanium and other metals. After such treatment, the molten iron has low silicon and manganese content, and there is also a certain amount of carbon loss, which is the so-called semi-steel. When semi-steel enters the steelmaking converter smelting process, a slag-making agent must be added to participate in the slag-making process of the steelmaking process to ensure the formation of slag with corresponding metallurgical effects. The current converter slag-making agent is an environmentally friendly product produced with steelmaking dust and sludge as the main raw materials, and quartz sand and other raw materials are added in a certain proportion, as shown in Table 1, and its technical index requirements are shown in Table 2.

[0003] Table 1 Converter slag making agent formula

[0004] Name Dust removal ash Quartz sand Steelmaking sludge Binder Mass fraction ratio / % 42 43 0～10 5

[0005] Table 2 Technical index requirements for converter slag-making agent

[0006]

[0007]

[0008] The existing slag-making agent uses steelmaking dust and quartz sand as the main raw materials for briquetting, and the sulfur content is also close to 0.2%. During use, it causes the average increase of molten steel [S] to 0.002-0.005%, which brings difficulties to the smelting of ultra-low sulfur steel (steel grade judgment steel S≤0.005%).

[0009] In addition, nearly 90% of my country's titanium resources are found in vanadium-titanium magnetite in the Panzhihua area. The development of titanium resources includes titanium dioxide, titanium sponge, titanium metal and titanium alloy. Among them, a large amount of waste salt will be generated when obtaining titanium sponge through the molten salt chlorination method, and these waste salts cannot be directly discharged because they contain high chloride ions. The "crushing-lime mixing-heaping" method is generally used in China for treatment. The pollution of chlorides to the environment has not been fundamentally solved, which hinders the promotion and application of the molten salt chlorination method, resulting in the inability to use my country's titanium resources on a large scale. In order to meet the production needs of the high-end titanium industry, waste salts need to be treated. The main dry-based by-products produced in the process of treating waste salts are iron-manganese slag (i.e., dry-based iron hydroxide mixture), which belongs to metal oxides such as iron and manganese, containing Fe (25%-38%) and Mn (about 4%-5%), and have practical utilization value.

[0010] In addition, the waste continuous casting contains a high content of MgO, which has recycling value. The waste continuous casting tundish is crushed and called the waste tundish dry material. The chemical composition is shown in Table 3.

[0011] Table 3 Main Chemical Components of Dry Materials in Waste Medium Ladles

[0012]

[0013] Therefore, to solve the problems of recycling waste iron-manganese slag generated during the development of titanium resources and the waste from continuous casting, this patent explores and tests from the aspect of producing slag-making agents for steelmaking and verifies its feasibility. Summary of the Invention

[0014] The purpose of the present invention is to provide a slag-making agent for semi-steel steelmaking production and its preparation method to solve the problem of how to prepare a slag-making agent by using waste iron-manganese slag and continuous casting waste generated during the development of titanium resources.

[0015] To achieve the above object, the present invention provides a slag-making agent for semi-steel steelmaking production, and the slag-making agent includes: steelmaking dedusting ash, iron-manganese slag, dry materials in waste medium ladles, quartz sand and binder.

[0016] Optionally, the mass percentages of the steelmaking dedusting ash, the iron-manganese slag, the dry materials in waste medium ladles, the quartz sand and the binder are 25%, 10%, 10%, 50% and 5% respectively.

[0017] Optionally, the mass percentages of the steelmaking dedusting ash, the iron-manganese slag, the dry materials in waste medium ladles, the quartz sand and the binder are 25%, 15%, 10%, 45% and 5% respectively.

[0018] Optionally, the waste continuous casting tundish generated during the steelmaking process is crushed to obtain the dry materials in waste medium ladles.

[0019] Optionally, the waste salt generated during the development of titanium resources is processed to obtain the iron-manganese slag.

[0020] Optionally, the Fe content in the iron-manganese slag is 25%-38% and the Mn content is 4%-5%.

[0021] Optionally, the main component in the dry materials in waste medium ladles is MgO.

[0022] Optionally, the steelmaking dedusting ash includes: CaO, MgO, SiO2 and FeO.

[0023] Optionally, the binder includes: organic matter and inorganic matter, wherein the organic matter includes: carboxymethyl cellulose, and the inorganic matter includes: soda ash, bentonite and microsilica.

[0024] The present invention also provides a preparation method of a slag-making agent for semi-steel steelmaking production, and the method includes:

[0025] Mix steelmaking dedusting ash, ferromanganese slag, waste tundish dry material, quartz sand and binder in proportion to obtain a mixture;

[0026] Perform pelletizing operation on the mixture to obtain pellets;

[0027] Perform drying treatment on the pellets to obtain a slag-making agent.

[0028] The technical effects and advantages of the present invention:

[0029] The present invention provides a slag-making agent for semi-steel steelmaking production, and the slag-making agent includes: steelmaking dedusting ash, ferromanganese slag, waste tundish dry material, quartz sand and binder. Adding ferromanganese slag and waste tundish dry material to the slag-making agent of the present invention has no impact on the original process and no large amount of harmful substances are produced. It can replace steelmaking dedusting ash and steelmaking sludge to produce slag-making agent, solving the problems of waste ferromanganese slag generated in the process of titanium resource development and waste continuous casting tundish generated in the process of steelmaking continuous casting production, realizing "turning waste into treasure". The reduced amount of steelmaking dedusting ash and sludge can be added as raw materials for sinter.

[0030] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structure pointed out in the specification and the drawings. Brief Description of the Drawings

[0031] Figure 1 It is a flowchart of the preparation method of the slag-making agent for semi-steel steelmaking production. Detailed Embodiments

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0034] To solve the deficiencies of the prior art, the present invention discloses a slag-forming agent for semi-steel steelmaking production. The slag-forming agent includes: steelmaking dust removal ash, ferromanganese slag, waste tundish dry material, quartz sand, and binder. The present invention utilizes the waste ferromanganese slag generated during the development of titanium resources and the waste tundish dry material generated during continuous casting production of steel to prepare the slag-forming agent, achieving the effective utilization of resources and alleviating problems such as environmental pollution.

[0035] To better understand this solution, the following provides a detailed introduction to the slag-forming agent for semi-steel steelmaking production.

[0036] The slag-forming agent includes: steelmaking dust removal ash, ferromanganese slag, waste tundish dry material, quartz sand, and binder.

[0037] It should be noted that in order to recycle the waste ferromanganese slag generated during the development of titanium resources and the waste tundish dry material generated during the continuous casting production of steel, these two wastes are formulated into a slag-forming agent according to Table 4. Formulation 1: The mass percentages of the steelmaking dust removal ash, the ferromanganese slag, the waste tundish dry material, the quartz sand, and the binder are 25%, 10%, 10%, 50%, and 5% respectively. Formulation 2: The mass percentages of the steelmaking dust removal ash, the ferromanganese slag, the waste tundish dry material, the quartz sand, and the binder are 25%, 15%, 10%, 45%, and 5% respectively.

[0038] Table 4 Raw material ratio of the slag-forming agent

[0039]

[0040] It also should be noted that the waste tundish in the steelmaking process is crushed to obtain the waste tundish dry material. Among them, the main component in the waste tundish dry material is MgO.

[0041] It should also be noted that the waste salt generated from titanium resource development is treated to obtain the iron-manganese slag. Among them, the Fe content in the iron-manganese slag is 25%-38%, and the Mn content is 4%-5%.

[0042] It should also be noted that the dust and ash from the steelmaking converter are particulate matters generated during the steelmaking production process, and its components include CaO, MgO, SiO2, and FeO.

[0043] It should also be noted that the binder includes: organic matter and inorganic matter. Among them, the organic matter includes: carboxymethyl cellulose, and the inorganic matter includes: soda ash, bentonite, microsilica powder, etc.

[0044] It should also be noted that the technical index requirements of the slag former are shown in Table 5.

[0045] Table 5 Technical Index Requirements of the Slag Former

[0046] Composition <![CDATA[SiO2]]> MgO TFe P S Moisture Requirement (%) 50～60 ≥5 ≥10 ≤0.1 ≤0.2 ≤1.0

[0047] To illustrate the feasibility of this slag former, it will be explained from the following aspects.

[0048] (I) Chemical Analysis Results of the Slag Former

[0049] During the use of the slag former, samples of the slag former were taken, and the results are as follows:

[0050] Table 6 Composition of the Slag Former

[0051]

[0052]

[0053] It can be seen from Table 6 that the chemical compositions of the slag formers of the two formulations both meet the technical index requirements of the converter slag former. Among them, the S element is <0.070% in both cases, which is significantly lower than the S element in the original converter slag former (see Table 2), effectively reducing the "sulfur return" phenomenon during steelmaking and improving the yield rate of quality steel.

[0054] (II) Addition and Use of the Slag Former

[0055] 1. Test furnace charges of Scheme 1: The addition amounts of auxiliary materials such as lime and the slag former are carried out according to the existing regulations, and the final slag basicity is controlled at 3-4. Among them, the existing regulations are: the addition amount of quicklime is 22 Kg / t steel - 30 Kg / t steel, and the addition amount of the slag former is 12 Kg / t steel - 14 Kg / t steel.

[0056] Test heats for Plan 2: The addition amount of slag formers is 1.1 times that of the existing regulations, and the other auxiliary materials are added according to the slag condition and the requirements of molten steel composition. The basicity of the final slag is controlled at 3 - 4. Among them, the existing regulations are: the addition amount of quicklime is 22 Kg / t - 30 Kg / t of molten steel, and the addition amount of slag formers is 13 Kg / t - 15 Kg / t of molten steel.

[0057] 2. The hot metal conditions during use are shown in Table 7. In terms of the addition amount of hot metal, the two plans are basically the same as the comparison heat. The average tapping temperature of the comparison heat is 1313.7 °C, slightly lower than that of Plan 1 and Plan 2. The tapping temperature of the test heats with slag formers is 12 - 24 °C higher than that of the comparison heat; the average tapping temperature of industrial mass production is 1651.1 °C, lower than that of Plan 2 and higher than that of Plan 1, indicating that the two ratios of ferromanganese slag have little effect on the tapping temperature. From the phosphorus content on the small platform, it can be obtained that with the addition of ferromanganese slag and waste tundish dry materials, the phosphorus content gradually decreases, which will reduce the "cold brittleness" of steel and improve the plasticity and toughness of steel at normal temperature.

[0058] Among them, the comparative example is the steelmaking process data of the slag former in the background (prepared from quartz sand and steelmaking sludge).

[0059] Table 7 Hot Metal Conditions and Smelting Parameters

[0060]

[0061]

[0062] For the two plans, the active lime and high-magnesium lime are basically the same as those of the comparison heat, indicating that the addition of ferromanganese slag and tundish waste dry materials has no effect on slag formation during the steelmaking process, as shown in Table 8.

[0063] Table 8 Single Consumption of Steelmaking Materials (kg / ton of steel)

[0064] Type Existing slag-making agent Slag-making agent Active lime High-magnesium lime Comparison 17.76 \ 20.76 16.93 Scheme 1 \ 17.21 20.89 17.12 Scheme 2 \ 20.62 20.94 15.97

[0065] Compared with the comparison heat, the content of final carbon is basically the same for the two plans, which is closely related to the steel grade being smelted. The phosphorus content has decreased, and with the increase of the ferromanganese slag content in the slag former, the phosphorus content gradually decreases, which is beneficial to the product quality of steel, as shown in Table 9.

[0066] Table 9 Analysis of Each Element Composition of Converter Final Steel Samples

[0067] Type C / ％ P / ％ Mn / % Comparison 0.050 0.0087 0.021 Scheme 1 0.052 0.0074 0.020 Scheme 2 0.083 0.0058 0.018

[0068] The composition differences in the steel slag samples of the two plans and the comparison heat are small, without obvious fluctuations, and have no impact on the entire steelmaking system, as shown in Table 10.

[0069] Table 10 Analysis and Detection Results of Steel Slag Samples

[0070] Type P / ％ CaO / % FeO / % MgO / % MnO / % TFe / % <![CDATA[SiO2 / %]]> Comparison 0.778 37.48 20.57 12.98 1.01 25.66 11.27 Scheme 1 0.760 37.31 22.67 12.64 0.89 25.78 11.69 Scheme 2 0.646 37.11 22.28 13.41 0.88 25.83 10.59

[0071] It can be seen from the temperature of molten steel during tapping and charging, the unit consumption of steelmaking materials, and the composition data of steel samples and steel slag samples that adding ferromanganese slag and tundish waste dry material to the slag former has no impact on the original process, and no large amount of harmful substances are produced. It can replace steelmaking dust removal ash and steelmaking sludge to produce slag former, solving problems such as ferromanganese slag, which is a waste generated during titanium resource development, and waste tundish during continuous casting production in steelmaking, achieving "turning waste into treasure". Moreover, the reduced amount of steelmaking dust removal ash and sludge can be used as raw materials for sintered ore for batching.

[0072] The present invention also provides a preparation method for a slag former used in semi-steel steelmaking production, as Figure 1 shown. The method includes: uniformly mixing steelmaking dust removal ash, ferromanganese slag, tundish waste dry material, quartz sand and binder to obtain a mixture; performing a pelletizing operation on the mixture to obtain pellets; and performing a drying treatment on the pellets to obtain the slag former.

[0073] The present invention provides a slag former for semi-steel steelmaking production. The slag former includes: steelmaking dust removal ash, ferromanganese slag, tundish waste dry material, quartz sand and binder. Adding ferromanganese slag and tundish waste dry material to the slag former of the present invention has no impact on the original process, and no large amount of harmful substances are produced. It can replace steelmaking dust removal ash and steelmaking sludge to produce slag former, solving problems such as ferromanganese slag, which is a waste generated during titanium resource development, and waste tundish during continuous casting production in steelmaking, achieving "turning waste into treasure". Moreover, the reduced amount of steelmaking dust removal ash and sludge can be used as raw materials for sintered ore for batching.

[0074] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A slag-forming agent for semi-steel steelmaking production, characterized in that, The slag former includes: steelmaking dedusting ash, ferromanganese slag, waste tundish dry material, quartz sand and binder; Among them, the mass percentages of the steelmaking dedusting ash, the ferromanganese slag, the waste tundish dry material, the quartz sand and the binder are 25%, 10%, 10%, 50% and 5% respectively, or the mass percentages of the steelmaking dedusting ash, the ferromanganese slag, the waste tundish dry material, the quartz sand and the binder are 25%, 15%, 10%, 45% and 5% respectively; Among them, the waste salt generated from titanium resource development is treated to obtain the ferromanganese slag.

2. The slag former for semi-steel steelmaking production according to claim 1, wherein, The waste continuous casting tundish generated during the steelmaking process is crushed to obtain the waste tundish dry material.

3. The slag-forming agent for semi-steel steelmaking production according to claim 1, wherein The Fe content in the ferromanganese slag is 25%-38%, and the Mn content is 4%-5%.

4. The slag former for semi-steel steelmaking production according to claim 1 or 2, characterized in that, The main component in the waste tundish dry material is MgO.

5. The slag former for semi-steel steelmaking production according to claim 1, characterized in that, The steelmaking dedusting ash includes: CaO, MgO, SiO2 and FeO.

6. The slag-forming agent for semi-steel steelmaking production according to claim 1, characterized in that, The binder includes: organic matter and inorganic matter. Among them, the organic matter includes: carboxymethyl cellulose, and the inorganic matter includes: soda ash, bentonite and microsilica powder.

7. A preparation method of a slag-making agent for semi-steel steelmaking production, characterized in that, The method includes: The steelmaking dedusting ash, ferromanganese slag, waste tundish dry material, quartz sand and binder are uniformly mixed in proportion to obtain a mixture; The mixture is pelletized to obtain pellets; The pellets are dried to obtain the slag former; Among them, the mass percentages of the steelmaking dedusting ash, the ferromanganese slag, the waste tundish dry material, the quartz sand and the binder are 25%, 10%, 10%, 50% and 5% respectively, or the mass percentages of the steelmaking dedusting ash, the ferromanganese slag, the waste tundish dry material, the quartz sand and the binder are 25%, 15%, 10%, 45% and 5% respectively; Among them, the waste salt generated from titanium resource development is treated to obtain the ferromanganese slag.

Images