A slagging agent, its preparation method and hard wire steel

Abstract

The application belongs to the technical field of waste residue recycling, and specifically provides a slagging agent, a preparation method thereof and hard wire steel. Through accurate control of the composition and alkalinity of the slagging agent, the slagging time is shortened without using fluorite, and the desulfurization effect on the hard wire steel is ensured, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of recycling of waste slag, and particularly relates to a slag converter, a preparation method thereof and a hard wire steel. BACKGROUND

[0002] Steel slag is a waste slag produced in the metallurgical industry, however, the steel slag is not a useless solid waste, and contains a large amount of slag steel, calcium oxide, iron and magnesium oxide and other useful components. Therefore, in order to create economic and environmental benefits for the steel enterprise, it is necessary and urgent to select a suitable treatment process and utilization approach to develop the recycling value of the steel slag.

[0003] At present, the recycling approaches of the steel slag mainly include civil engineering, road construction, agricultural fertilizer and recycling by being added into sintering and blast furnace. In addition, the steel slag is used for cement production after the components of the steel slag are reconstructed by adding carbon, silicon and aluminum materials into the molten steel slag and the slag steel is recycled.

[0004] There are few reports about the recycling of the acid refining slag, and the acid refining slag is treated as waste slag by most enterprises due to the low alkalinity, low melting point and certain erosion to refractory materials, thereby causing environmental pollution and resource waste. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the defect that the acid refining slag cannot be recycled in the prior art, so as to provide a slag converter, a preparation method thereof and a hard wire steel.

[0006] Therefore, the present application provides a slag converter, characterized in that the alkalinity of the slag converter is 1.5-2.5, and the chemical components of the slag converter include, in percentage by mass, CaO: 54-62%, SiO2: 25-35%, MgO: 3-8%, MnO≤1%, T.Fe≤1%, CaF2≤2%, Al2O3≤4%, and S≤0.04%. Further, the slag converter can further include inevitable impurities.

[0007] In the present application, the term alkalinity refers to the ratio of the mass percentages of CaO and SiO2 in the slag, which is obtained by XRF fluorescence analysis method.

[0008] Further, the chemical components of the slag converter include, in percentage by mass, CaO: 54-62%, SiO2: 25-35%, MgO: 3-8%, MnO≤1%, T.Fe≤1%, CaF2≤2%, Al2O3≤4%, and S≤0.04%, and the balance is inevitable impurities.

[0009] The present application further provides a preparation method of the slag converter, characterized in that the preparation method comprises mixing the acid refining slag with lime powder, cooling and crushing to obtain the slag converter.

[0010] In the present application, the term "acidic refining slag" refers to a refining slag with a basicity of less than 1.4.

[0011] Preferably, the compound components of the acidic refining slag include, in percentage by mass: CaO: 30-45%, SiO2: 38-50%, MgO: 5-10%, MnO: 1-2%, T.Fe: 1-2%, CaF2≤3%, Al2O3≤5%, S≤0.05%. Further, it can also include inevitable impurities.

[0012] Further, the compound components of the acidic refining slag include, in percentage by mass: CaO: 30-45%, SiO2: 38-50%, MgO: 5-10%, MnO: 1-2%, T.Fe: 1-2%, CaF2≤3%, Al2O3≤5%, S≤0.05%, and the balance is inevitable impurities.

[0013] Preferably, the basicity of the refining slag is 0.6-1.2.

[0014] Further, the mixing includes the steps of pouring the slag and spreading lime powder; the pouring of the slag is pouring the acidic refining slag, and the spreading of the lime powder is spreading lime powder on the acidic refining slag; preferably, the steps of pouring the slag and spreading the lime powder are repeated multiple times; preferably, the method further includes the step of pre-spreading lime powder at the bottom of the mixing container before pouring the slag; preferably, the temperature of the acidic refining slag is 1000-1200℃.

[0015] Further, the mass ratio of the acidic refining slag to the lime powder is 1-10:1, preferably 5-6:4.

[0016] Further, the mass of the pre-spreading lime powder accounts for 1-10:1, preferably 4:5-6, of the mass of the acidic refining slag in the first pouring process.

[0017] Further, the particle size of the lime powder is 0.05-2.5mm, preferably 0.2-1.0mm.

[0018] The present application also provides a method for preparing hard wire steel, including a converter smelting process, wherein in the converter smelting process, the slagging agent or any of the above-mentioned slagging agents is used for slagging.

[0019] Further, the converter smelting process also satisfies at least one of the following A-E:

[0020] A. In the slagging process, the slagging agent is added when the tapping molten steel is 65-75%, and the addition is completed when the tapping molten steel is 85-95%;

[0021] B, the slagging agent is added, and 4-8 kg of lime is also added per ton of molten steel; and / or, 2-3 kg of the slagging agent is added per ton of molten steel;

[0022] C, the oxygen content of the molten steel is 0.025-0.075% when tapping; and / or, the C content of the molten steel at the end of the converter smelting is 0.05-0.15%, the P content is 0.008-0.020%, and the S content is 0.012-0.018%;

[0023] D, alloying and deoxidation are performed by adding alloy and carbon powder into the ladle at the beginning of tapping, and then the slagging agent is added for slagging; preferably, 1.8-2.0 kg / t of ferrosilicon alloy, 6.5-6.6 kg / t of manganese-silicon alloy, and 6.2-6.4 kg / t of carbon powder are added;

[0024] E, the slagging temperature is 1610-1640℃, and the slagging time is 0.5-3.5 min.

[0025] In the present application, deoxidation and alloying are performed by adding 1.8-2.0 kg / t of ferrosilicon alloy, 6.5-6.6 kg / t of manganese-silicon alloy, and 6.2-6.4 kg / t of carbon powder into the ladle at the beginning of tapping, and the use of lime and slagging agent further improves the efficiency of slagging and desulfurization.

[0026] Further, the method for preparing the hard wire steel further comprises LF refining, continuous casting, descaling, rough rolling, finish rolling, wire drawing, and cooling processes after the converter smelting process; preferably, the method for preparing the hard wire steel satisfies at least one of the following (1)-(7):

[0027] (1) in the LF refining process, the inlet temperature is 1590-1620℃, the outlet temperature is 1520-1540℃, 0.5-1.5 kg / t of calcium carbide is added after entering to deoxidize the slag, the bottom blowing flow rate of the ladle is 800-1200 NL / min, after treatment for 15-35 min, the bottom blowing flow rate is reduced to below 100 NL / min, soft blowing is performed, and the soft blowing time is greater than 8 min;

[0028] (2) in the continuous casting process, the superheat is controlled to be 15-35℃;

[0029] (3) in the descaling process, high-pressure water with a water pressure of 10-16 MPa is used for descaling;

[0030] (4) in the rough rolling process, the rough rolling temperature is controlled to be 1050-1100℃;

[0031] (5) in the finish rolling process, the finish rolling machine inlet temperature is controlled to be 930-980℃, and the outlet temperature is below 1030℃;

[0032] (6) the wire-drawing process, the wire-drawing temperature is controlled to be 900-950 DEG C;

[0033] (7) the cooling is Stelmor cooling.

[0034] The application further provides the hard wire steel prepared by the preparation method.

[0035] Further, the chemical composition of the hard wire steel includes, in percentage by mass, C: 0.60-0.81%, Si: 0.15-0.25%, Mn: 0.50-0.60%, and S: ≤0.012%.

[0036] The chemical composition of the hard wire steel further includes P: ≤0.014%, Cr: ≤0.1%, Ni: ≤0.05%, Cu: ≤0.05%, O: ≤0.002%, and N: ≤0.005%, and the balance is Fe and other inevitable impurities.

[0037] The technical scheme of the application has the following advantages:

[0038] 1. The slagging agent provided by the application can shorten the slagging time and significantly improve the desulfurization effect and production efficiency without using fluorite, by precisely controlling the composition and alkalinity of the slagging agent, which comprises CaO: 54-62%, SiO2: 25-35%, MgO: 3-8%, MnO: ≤1%, T.Fe: ≤1%, CaF2: ≤2%, Al2O3: ≤4%, and S: ≤0.04%.

[0039] 2. The preparation method of the slagging agent provided by the application comprises mixing acid refining slag with lime powder, cooling, crushing, and sieving to obtain the slagging agent.

[0040] 3. The preparation method of the slagging agent provided by the application comprises mixing acid refining slag with lime powder, cooling, crushing, and sieving to obtain the slagging agent.

[0041] 4. The preparation method of the hard wire steel provided by the present application, wherein the slagging agent is added when the tapping molten steel is 65-75%, and the adding is completed when the tapping molten steel is 85-95% during the slagging process, so that the slagging efficiency and desulfurization effect can be further improved. DETAILED DESCRIPTION

[0042] The following examples are provided to better further understand the present application, and are not limited to the best mode, and do not constitute a limitation on the content and protection scope of the present application. Any person under the inspiration of the present application or the combination of the present application with other prior art features can obtain any product same or similar to the present application, which falls within the protection scope of the present application.

[0043] In the examples, the specific experimental steps or conditions are not specified, and can be operated according to the conventional experimental steps described in the literature in the field. The reagents or instruments used are not specified by the manufacturer, and are conventional reagent products that can be obtained by purchase.

[0044] Example 1

[0045] The present embodiment provides a slagging agent and a preparation method thereof, and the preparation method of the slagging agent comprises the following steps:

[0046] (1) Lime powder is pre-spread on the bottom of the slag basin, and the average particle size of the lime powder is 0.34 mm. The casting residue (also called acidic refining slag) with a temperature of 1150°C is poured into the slag basin and mixed with the lime powder, wherein the mass ratio of the acidic refining slag and the lime powder is 6:4. Then, the air cooling is started, and the dust removal machine is started to remove dust. The operation of pouring slag and spreading lime powder is repeated 12 times, that is, after pouring one furnace of acidic refining slag, one layer of lime powder is spread according to the above mass ratio for covering, mixing, cooling and crushing to obtain mixed slag. The acidic refining slag used is the acidic refining slag produced after the continuous casting of the cord steel, and the basicity thereof is 0.8. The composition and mass percentage of the slag are as follows: CaO: 36%, SiO2: 45%, MgO: 10%, MnO: 1.0%, T.Fe: 0.9%, CaF2: 1.8%, Al2O 3： 3.1%, S: 0.043%, and the others are inevitable impurities.

[0047] (2) After the temperature of the mixed slag is reduced to 50°C, it is turned over into a jaw crusher for crushing and screening to obtain the slagging agent. The particle size of the slagging agent is 10-50 mm, accounting for 93 wt%, and the particle size <10 mm and >50 mm accounts for 7 wt%.

[0048] The slag converter has a basicity of 2.3, and the chemical composition of the slag converter is as follows in terms of mass percentage: CaO: 62%, SiO2: 27%, MgO: 6%, MnO: 0.6%, T.Fe: 0.6%, CaF2: 1.2%, Al2O 3： 1.8%, S: 0.026%, and the rest is inevitable impurities.

[0049] The embodiment also provides a 70 hard wire steel and a preparation method thereof, and a flow thereof is as follows: converter smelting, LF refining, continuous casting, descaling, rough rolling, finish rolling, wire drawing and Stelmor cooling.

[0050] In the converter smelting process, the C content of the converter end-point molten steel is controlled to be 0.06%, the P content is 0.012%, and the S content is 0.015%. When tapping, the oxygen content of the molten steel is 0.055%, and at the beginning of tapping, 1.8 kg / t of FeSi75-B alloy, 6.5 kg / t of FeMn68Si18(III) alloy and 6.2 kg / t of carbon powder are added into the ladle for deoxidation and alloying, then at the time of 70% of the molten steel being tapped, 2 kg / t of the slag converter of the embodiment and 6 kg / t of lime are added for slagging, and the adding is completed at the time of 90% of the molten steel being tapped. The slagging temperature is 1635 ℃, and the slagging time is 1 min.

[0051] In the LF refining process, the inlet temperature is 1610 ℃, the outlet temperature is 1532 ℃, the ladle bottom blowing flow is 1000 NL / min, 1.2 kg / t of calcium carbide is added to deoxidize the slag, and after 20 min of treatment, the bottom blowing flow is reduced to 80 NL / min, and the soft blowing time is 10 min.

[0052] In the continuous casting process, the superheat is controlled to be 30 ℃. In the descaling process, high-pressure water is used for descaling, and the water pressure is 15 MPa. In the rough rolling process, the rough rolling temperature is controlled to be 1080 ℃. In the finish rolling process, the finish rolling machine inlet temperature is controlled to be 960 ℃, and the outlet temperature is 1020 ℃. In the wire drawing process, the wire drawing temperature is controlled to be 940 ℃. In the cooling process, the 6th-14th fans are turned on to control the air flow of each fan to be 100%.

[0053] The chemical composition of the final hard wire steel product is as follows in terms of mass percentage: C: 0.718%, Si: 0.184%, Mn: 0.518%, S: 0.0032%, P: 0.011%, Cr: 0.0121%, Ni: 0.0213%, Cu: 0.0234%, O: 0.00187%, N: 0.00351%, and the rest is Fe and other inevitable impurities.

[0054] Example 2

[0055] The embodiment provides a preparation method of a slag converter, and the preparation method comprises the following steps:

[0056] (1) In the bottom of the slag basin, lime powder with an average particle size of 0.22 mm is spread, and the acid refining slag with a temperature of 1200℃ is poured into the slag basin for mixing, and the mass ratio of the acid refining slag and the lime powder is 5:4. Then the air cooling is started, and the dust removal machine is started for dust removal. The operation of pouring slag and spreading lime powder is repeated 11 times, that is, after pouring one furnace of acid refining slag, a layer of lime powder is spread according to the above mass ratio for covering, mixing, cooling and crushing to obtain mixed slag. Among them, the acid refining slag is generated after the cord steel continuous casting is finished, the basicity is 0.6, and the slag composition and mass percentage are as follows: CaO: 30%, SiO2: 50%, MgO: 10%, MnO: 0.8%, T.Fe: 1.0%, CaF2: 1.8%, Al2O 3： 1.8%, S: 0.05%, and the others are inevitable impurities.

[0057] (2) After the temperature of the mixed slag is reduced to 60℃, it is poured into a jaw crusher for crushing and screening to obtain a slag refining agent. Among them, the slag refining agent with a particle size of 10-50 mm accounts for 90wt%, and the slag refining agent with a particle size of <10 mm and >50 mm accounts for 10wt%. The basicity of the slag refining agent is 2.2, and the chemical composition of the slag refining agent is as follows in terms of mass percentage: CaO: 62%, SiO2: 28%, MgO: 5.7%, MnO: 0.54%, T.Fe: 0.57%, CaF2: 0.9%, Al2O 3： 1.1%, S: 0.028%, and the others are inevitable impurities.

[0058] The embodiment also provides an 80 hard wire steel and a preparation method thereof, and the flow is as follows: converter smelting, LF refining, continuous casting, descaling, primary rolling, finish rolling, wire drawing and Stelmor cooling.

[0059] In the converter smelting process, the steel composition at the end of the converter is controlled to be C: 0.05%, P: 0.015%, and S: 0.018%. When the steel is tapped, the oxygen content of the molten steel is 0.075%, and at the beginning of the tapping, 2.0 kg / t of FeSi75-B alloy, 6.6 kg / t of FeMn68Si18(III) alloy and 6.4 kg / t of carbon powder are added to the ladle for deoxidation and alloying, and then at 65% of the tapping of the molten steel, 2.5 kg / t of the slag refining agent and 8 kg / t of lime are added for slag refining, and the addition is completed at 85% of the tapping of the molten steel, and the slag refining temperature is 1640℃, and the slag refining time is 0.5 min.

[0060] In the LF refining process, the inlet temperature is 1620℃, the outlet temperature is 1540℃, the bottom blowing flow of the ladle is 1200 NL / min, 1.2 kg / t of calcium carbide is added to deoxidize the slag, and after 30 min of treatment, the bottom blowing flow is reduced to 100 NL / min, and the soft blowing time is 12 min.

[0061] In the continuous casting process, the superheat is controlled to be 35℃. In the descaling process, high pressure water is used for descaling, and the water pressure is 16MPa. In the rough rolling process, the rough rolling temperature is controlled to be 1100℃. In the finish rolling process, the finish rolling machine inlet temperature is controlled to be 980℃, and the outlet temperature is controlled to be 1030℃. In the wire drawing process, the wire drawing temperature is controlled to be 950℃. In the cooling process, the 6th-14th fans are turned on, and the air volume of the turned-on fans is controlled to be 100%.

[0062] The chemical composition of the final hard wire steel product is as follows in terms of mass percentage: C: 0.807%, Si: 0.192%, Mn: 0.526%, S: 0.0046%, P: 0.0138%, Cr: 0.0113%, Ni: 0.0221%, Cu: 0.0221%, O: 0.00163%, N: 0.00324%, and the balance is Fe and other inevitable impurities.

[0063] Example 3

[0064] The preparation method of the slag conditioning agent provided in this example is basically the same as that in Example 1, except that the average particle size of the lime powder used in step (1) is 0.05mm. The basicity of the slag conditioning agent obtained in this example is 1.8, and the chemical composition of the slag conditioning agent is as follows in terms of mass percentage: CaO: 54%, SiO2: 30%, MgO: 6.5%, MnO: 0.68%, T.Fe: 0.66%, CaF2: 1.3%, Al2O 3： 2.0%, S: 0.029%, and the balance is inevitable impurities.

[0065] This example also provides a 70 hard wire steel and a preparation method thereof, and the process conditions are basically the same as those in Example 1, except that the slag conditioning agent prepared in this example is used for slag conditioning treatment, and the slag conditioning time is 1.1min.

[0066] The chemical composition of the final hard wire steel product is as follows in terms of mass percentage: C: 0.725%, Si: 0.187%, Mn: 0.531%, S: 0.0046%, P: 0.0118%, Cr: 0.0153%, Ni: 0.0224%, Cu: 0.0225%, O: 0.00195%, N: 0.00363%, and the balance is Fe and other inevitable impurities.

[0067] Example 4

[0068] The embodiment provides a preparation method of a slagging agent, which is basically same as that of the embodiment 1, and the difference is that the average particle size of the lime powder used in the step (1) is 2.1 mm. The basicity of the slagging agent obtained in the embodiment is 2.2, and the chemical composition of the slagging agent is as follows in terms of percentage by mass: CaO: 61%, SiO2: 28%, MgO: 6%, MnO: 0.58%, T.Fe: 0.62%, CaF2: 1.2%, Al2O 3： 1.8%, S: 0.026%, and the others are inevitable impurities.

[0069] The embodiment also provides a 70 hard wire steel and a preparation method thereof, and the process conditions are basically same as those of the embodiment 1, and the difference is that the slagging agent obtained in the embodiment is used for slagging treatment, and the slagging time is 3.4 min.

[0070] The chemical composition of the final hard wire steel product is as follows in terms of percentage by mass: C: 0.729%, Si: 0.199%, Mn: 0.529%, S: 0.0059%, P: 0.0105%, Cr: 0.0142%, Ni: 0.0232%, Cu: 0.021%, O: 0.00177%, N: 0.00366%, and the balance is Fe and other inevitable impurities.

[0071] Embodiment 5

[0072] The embodiment also provides a 70 hard wire steel and a preparation method thereof, and the process conditions are basically same as those of the embodiment 1, and the difference is that, in the converter smelting process, the slagging agent and the lime are added after the tapping is completed, and the slagging time is 3.5 min.

[0073] The chemical composition of the final hard wire steel product is as follows in terms of percentage by mass: C: 0.726%, Si: 0.186%, Mn: 0.518%, S: 0.0056%, P: 0.0109%, Cr: 0.0141%, Ni: 0.0212%, Cu: 0.0223%, O: 0.00182%, N: 0.00382%, and the balance is Fe and other inevitable impurities.

[0074] Embodiment 6

[0075] This embodiment also provides a 70 hard wire steel and its preparation method. The process conditions are basically the same as those in Embodiment 1. The only difference is that in the converter smelting process, "when the molten steel is 70% complete, 2 kg / t of the slag-forming agent of this embodiment and 6 kg / t of lime are added for slag formation, and the addition is completed when the molten steel is 90% complete" is replaced with "when the steel is first tapped, before adding the alloy, 2 kg / t of the slag-forming agent of this embodiment and 6 kg / t of lime are added for slag formation".

[0076] The final chemical composition of the hardened wire steel product, by mass percentage, is as follows: C: 0.723%, Si: 0.184%, Mn: 0.532%, S: 0.0047%, P: 0.0122%, Cr: 0.0132%, Ni: 0.0225%, Cu: 0.0227%, O: 0.00161%, N: 0.00357%, with the balance being Fe and other unavoidable impurities.

[0077] Comparative Example 1

[0078] This comparative example provides a 70 hard wire steel and its preparation method. The process conditions are basically the same as in Example 1, except that a slag-forming agent is not used. The original description of adding 2 kg / t of the slag-forming agent and 6 kg / t of lime at 70% molten steel tapping and completing the addition at 90% molten steel tapping is replaced with "adding 6 kg / t of lime at 70% molten steel tapping and completing the addition at 90% molten steel tapping." The slag-forming time is 8.3 minutes. During the LF refining process, it was found that the amount of slag added was insufficient; therefore, 2 kg / t of lime and 1 kg / t of fluorite were added to supplement the slag-forming process.

[0079] The final chemical composition of the hardened wire steel product, by mass percentage, is as follows: C: 0.724%, Si: 0.193%, Mn: 0.531%, S: 0.0063%, P: 0.0107%, Cr: 0.0098%, Ni: 0.0226%, Cu: 0.0225%, O: 0.00199%, N: 0.00395%, with the balance being Fe and other unavoidable impurities.

[0080] Comparative Example 2

[0081] This comparative example provides a 70 hard wire steel and its preparation method. The process conditions are basically the same as those in Example 5, except that the untreated acidic refining slag from Example 5 is used as the slag-forming agent, and the slag-forming time is 3.8 min.

[0082] The chemical composition of the final hard wire steel product is as follows in terms of mass percentage: C: 0.726%, Si: 0.203%, Mn: 0.529%, S: 0.0076%, P: 0.0121%, Cr: 0.0117%, Ni: 0.0227%, Cu: 0.0224%, O: 0.00193%, N: 0.00362%, and the balance being Fe and other inevitable impurities.

[0083] Comparative Example 3

[0084] The present comparative example provides a slagging agent and a preparation method thereof, the basicity of the slagging agent is 3.8, and the chemical composition of the slagging agent is as follows in terms of mass percentage: CaO: 68%, SiO2: 18%, MgO: 4.3%, MnO: 0.43%, T.Fe: 0.51%, CaF2: 1.1%, Al2O3: 2.2%, S: 0.033%, and the balance being inevitable impurities. The preparation method of the slagging agent is basically the same as that of Example 1, and the only difference is that the “mass ratio of the acidic refining slag to the lime powder is 6:4” is replaced by “mass ratio of the acidic refining slag to the lime powder is 4:6”.

[0085] The present example also provides a 70 hard wire steel and a preparation method thereof, and the process conditions are basically the same as those of Example 1, and the only difference is that 2 kg / t of the slagging agent of the present comparative example is used in the converter smelting process instead of the slagging agent of Example 1, and the slag material is not completely melted after slagging for 7.5 minutes, so 50 kg / t of fluorite is added for slagging at the LF refining inlet station, and the slag material is completely melted.

[0086] The chemical composition of the final hard wire steel product is as follows in terms of mass percentage: C: 0.723%, Si: 0.189%, Mn: 0.532%, S: 0.0083%, P: 0.0123%, Cr: 0.0125%, Ni: 0.0225%, Cu: 0.0225%, O: 0.00195%, N: 0.00364%, and the balance being Fe and other inevitable impurities.

[0087] Experimental Example 1

[0088] According to the sulfur content at the end of the converter and the sulfur content at the inlet of the LF, the desulfurization rate in the steel process is calculated according to the following formula: desulfurization rate in the steel process = (sulfur content at the end of the converter - sulfur content at the inlet of the LF) / sulfur content at the end of the converter * 100%. The chemical composition of each element in the steel is detected by a direct-reading spectrometer. The slagging time is the time from the addition of the slagging agent to the complete melting (complete melting means that the refining slag is observed to be completely red-hot and there is no blocky slag).

[0089] The results are shown in the following table.

[0090] Table 1 Test results table

[0091]

[0092] From the results of the above table, it can be seen that, by comparing Example 1 with Comparative Examples 1-3, the slagging agent of the present application can significantly shorten the slagging time without using fluorite, and is helpful for desulfurization.

[0093] By comparing Example 1 with Examples 3 and 4, it can be seen that, by controlling the particle size of lime powder within the preferred range, the desulfurization rate of the present application can be further improved, and the slagging time is shortened. If the particle size is too small, the loss is relatively large, and the dust emission is also relatively large, and the alkalinity of the slagging agent is relatively low, and the desulfurization rate is relatively poor. If the particle size of lime powder is too large, the uniformity of the slagging agent is relatively poor, and the desulfurization effect is relatively poor.

[0094] By comparing Example 1 with Examples 5 and 6, it can be seen that, by controlling the timing of adding the slagging agent within the preferred range, the present application can shorten the slagging time and further improve the desulfurization efficiency.

[0095] Obviously, the above examples are only examples for clearly illustrating, and are not limitations to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. It is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for preparing a slag-reducing agent, characterized in that, The process includes mixing acidic refining slag with lime powder, cooling, and crushing to obtain a slag-reducing agent, wherein the mass ratio of acidic refining slag to lime powder is 1-10:1; the chemical composition of the acidic refining slag, by mass percentage, includes: CaO: 30-45%, SiO2: 38-50%, MgO: 5-10%, MnO: 1-2%, T.Fe: 1-2%, CaF2≤3%, Al2O3≤5%, S≤0.05%; and the basicity of the refining slag is 0.6-0.

8. The mixing process includes the steps of dumping slag and spreading lime powder; dumping slag means pouring out the acidic refining slag, and spreading lime powder means spreading lime powder on the acidic refining slag; the temperature of the acidic refining slag is 1000-1200℃.

2. The method for preparing the slag-reducing agent according to claim 1, characterized in that, The mixing process includes repeatedly pouring slag and spreading lime powder.

3. The method for preparing the slag-reducing agent according to claim 2, characterized in that, The process also includes a step of pre-sprinkling lime powder at the bottom of the mixing container before pouring out the slag.

4. The method for preparing the slag-reducing agent according to claim 1, characterized in that, The mass ratio of the acidic refining slag to lime powder is 5-6:

4.

5. The method for preparing the slag-reducing agent according to any one of claims 1-4, characterized in that, The average particle size of the lime powder is 0.05-2.5 mm.

6. The method for preparing the slag-reducing agent according to claim 5, characterized in that, The average particle size of the lime powder is 0.2-1.0 mm.

7. A slag-reducing agent, characterized in that, The slag-reducing agent is obtained by any one of the preparation methods described in claims 1-6, wherein the alkalinity of the slag-reducing agent is 1.5-2.3, and the chemical composition of the slag-reducing agent by mass percentage includes: CaO: 54-62%, SiO2: 25-35%, MgO: 3-8%, MnO≤1%, T.Fe≤1%, CaF2≤2%, Al2O3≤4%, S≤0.04%.

8. A method for preparing hardened wire rod, characterized in that, It includes a converter smelting process, wherein, in the converter smelting and tapping process, the slag-forming agent described in claim 7 is used for slag formation.

9. The method for preparing hardened wire steel according to claim 8, characterized in that, The converter smelting and tapping process satisfies at least one of the following AE: A. During the slag-forming process, the slag-forming agent is added when the molten steel reaches 65-75% of its output, and the addition is completed when the molten steel reaches 85-95% of its output. B. Simultaneously with the addition of the slag-reducing agent, 4-8 kg of lime is also added per ton of molten steel; and / or, 2-3 kg of the slag-reducing agent is added per ton of molten steel; C. The oxygen content of the molten steel at tapping is 0.025-0.075%; and / or, the final molten steel from the converter smelting process has the following composition: C: 0.05-0.15%, P: 0.008-0.020%, S: 0.012-0.018%; D. At the beginning of tapping, alloys and carbon powder are added to the ladle for deoxidation and alloying, and then the slag-reducing agent is added for slag reduction. E. The slag-forming temperature is 1610-1640℃, and the slag-forming time is 0.5-3.5min.

10. The method for preparing hardened wire steel according to claim 9, characterized in that, Option D involves adding 1.8-2.0 kg / t of ferrosilicon alloy, 6.5-6.6 kg / t of manganese silicon alloy, and 6.2-6.4 kg / t of carbon powder for deoxidation and alloying.

11. The method for preparing hardened wire steel according to any one of claims 8-10, characterized in that, The process includes LF refining, continuous casting, descaling, primary rolling, finishing rolling, wire drawing, and cooling after the converter smelting process.

12. The method for preparing hardened wire steel according to claim 11, characterized in that, The method for preparing the hardened wire steel satisfies at least one of the following (1)-(7): (1) In the LF refining process, the inlet temperature is 1590-1620℃ and the outlet temperature is 1520-1540℃. After entering the station, 0.5-1.5 kg / t of calcium carbide is added to deoxidize the slag. The bottom blowing flow rate of the ladle is 800-1200 NL / min. After processing for 15-35 min, the bottom blowing flow rate is reduced to below 100 NL / min. Soft blowing is then carried out for more than 8 min. (2) In the continuous casting process, the superheat is controlled to be 15-35℃; (3) In the descaling process, descaling is performed under a water pressure of 10-16 MPa; (4) In the initial rolling process, the initial rolling temperature is controlled at 1050-1100℃; (5) In the finishing rolling process, the inlet temperature of the finishing mill is controlled to be 930-980℃ and the outlet temperature is below 1030℃; (6) In the silk-spinning process, the silk-spinning temperature is controlled at 900-950℃; (7) The cooling is Stellmore cooling.

13. A hardened wire steel prepared by any one of the preparation methods described in claims 8-12.

14. The hardened wire rod according to claim 13, characterized in that, The chemical composition of the hardened wire steel, by mass percentage, includes: C: 0.60-0.81%, Si: 0.15-0.25%, Mn: 0.50-0.60%, S: ≤0.012%.

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