Preparation method of low-carbon manganese-silicon alloy

Abstract

The invention provides a preparation method of a low-carbon manganese-silicon alloy, and belongs to the technical field of alloy smelting, and the preparation method comprises the following steps: S1, raw material pretreatment: weighing manganese ore, silica and coke in proportion, respectively performing crushing treatment, and uniformly mixing to form a furnace charge; lime and fluorite are taken, smashed to be smaller than 20 mm in particle size and then mixed to be uniform, and a slag former is formed; s2, smelting: feeding furnace charge and a slag former into an electric furnace together, electrifying and smelting for 3-4 hours to form alloy liquid, and then pouring the molten alloy liquid in the furnace into a ladle; s3, ladle-to-ladle: discharging the alloy liquid in the furnace, feeding the alloy liquid into a ladle, and carrying out ladle-to-ladle on the alloy liquid in the ladle; and S4, casting is conducted, specifically, after ladle-to-ladle is finished, alloy liquid is cast into a mold, cooling and solidification are conducted to form a casting blank, and the low-carbon manganese-silicon alloy is obtained. According to the method, the requirement for the manganese content in the manganese ore raw material is relatively low, the yield and the production scale can be increased, the production cost is reduced, and the product has the characteristics of low phosphorus and low sulfur.

Description

Technical Field

[0001] This invention relates to the field of alloy smelting technology, and in particular to a method for preparing a low-carbon manganese-silicon alloy. Background Technology

[0002] With the development of my country's steel industry, steel varieties are becoming increasingly diverse and their quality is constantly improving, leading to higher requirements for ferroalloy furnace materials. Ordinary ferromanganese alloys typically contain more than 1.0% carbon (C), and their main use is as a deoxidizer in steelmaking, oxidizing excess oxygen in molten steel and transferring it into the slag. However, due to the high carbon and phosphorus content of ordinary ferromanganese alloys, they cannot be used in the production of low-carbon and ultra-low-carbon steels, thus limiting their application scope.

[0003] Low-carbon ferromanganese alloy is an alloy composed of elements such as manganese, silicon, iron, and carbon. It has a higher silicon content (Si>22%) and lower carbon and phosphorus impurities (C<0.7%, P<0.2%). Compared to ordinary ferromanganese alloy, it has a wider range of applications. It is a commonly used deoxidizer in steelmaking, a reducing agent in the production of medium and low-carbon ferromanganese and in the electrosilicon heating process for producing metallic manganese, and can also replace ferrosilicon and low-carbon ferromanganese to reduce raw material costs. Furthermore, it can be used in the production of stainless steel and special low-carbon steels, such as welding wire steel and Q195 steel. Therefore, using low-carbon ferromanganese alloy to replace high-silicon ferromanganese and low-carbon ferromanganese or metallic manganese as a deoxidizer and additive in the smelting of manganese-based stainless steel, plate steel, and special steels has become a popular choice for many steel mills in China.

[0004] The production and smelting of low-carbon manganese silicon alloys often requires the use of high-grade manganese ore with low phosphorus and low carbon content (Mn > 42%), and the control of higher furnace temperatures to reduce manganese volatilization. This results in higher requirements for smelting raw materials and a corresponding increase in raw material costs. Furthermore, most domestic low-carbon manganese silicon alloy products are currently produced by simultaneously manufacturing medium- and low-carbon ferromanganese in a refining electric arc furnace, while adding ferrosilicon powder to liquid manganese slag and then using an external ladle for production. This production method has a small scale and cannot meet the large-scale demands of the steel industry. Summary of the Invention

[0005] This invention provides a method for preparing a low-carbon manganese silicon alloy that requires relatively low manganese content in manganese ore raw materials, can increase output and production scale, reduce production costs, and produces products with low phosphorus and low sulfur characteristics. This method solves the problems in the prior art, such as high raw material requirements, increased raw material costs, and production scale being easily limited by ferromanganese production.

[0006] This invention provides a method for preparing a low-carbon manganese-silicon alloy, comprising: S1. Raw material pretreatment: Weigh manganese ore, silica, and coke according to the proportion, crush them separately, and then mix them evenly to form furnace charge; take lime and fluorite, crush them separately to a particle size of less than 20mm, and then mix them evenly to form slagging agent; S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 3-4 hours to form an alloy liquid. Then the molten alloy liquid in the furnace is poured into the ladle. The furnace outlet temperature of the alloy liquid is not lower than 1650℃. S3, Ladle Transfer: The molten alloy in the furnace is poured out and sent into the ladle, and the molten alloy is transferred in the ladle. S4. Casting: After the pouring is completed, the alloy liquid is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese silicon alloy.

[0007] Further configured, the aforementioned low-carbon manganese-silicon alloy comprises the following components by mass fraction: Mn 60-65%, Si 25-27%, C 0.2-0.3%, P≤0.15%, S≤0.03%.

[0008] This invention uses manganese ore and silica to produce manganese-silicon alloy. The manganese content in the manganese ore raw material is required to be relatively low, which is conducive to increasing output and production scale and reducing production costs. The manganese and silicon content in the manganese-silicon alloy is controlled by precise batching. At the same time, the content of harmful elements such as carbon, phosphorus and sulfur is controlled by smelting. The preparation method is simple, resulting in a product that is low in carbon, phosphorus and sulfur, and has stable product quality. It can be used as a late-stage additive in steel smelting to increase silicon or manganese content, and can replace part or all of the metallic manganese to meet the requirements of smelting ultra-low carbon steel and reduce the cost of steel.

[0009] The weight ratio of manganese ore, silica, and coke in the furnace charge is further set to 1:(0.35-0.45):(0.22-0.40).

[0010] Further settings include manganese ore with Mn content ≥38%, particle size of 10-100mm, and no more than 10% of particles smaller than 10mm.

[0011] Further settings include a SiO2 content of ≥97% in the silica and a particle size of 10-100mm.

[0012] Further settings include a fixed carbon content of ≥83.5%, an ash content of ≤10%, and a particle size of 15-50 mm in the coke.

[0013] Manganese ore provides the main metallic component manganese, silica is used to generate silicon alloys, and coke is used as a reducing agent to reduce the compounds in manganese ore and silica to obtain manganese and silicon, releasing carbon monoxide / carbon dioxide. By precisely proportioning the three, the recovery rate of manganese and silicon can be improved, the resource utilization rate can be increased, and the carbon content of the alloy products can be avoided from exceeding the standard, thereby improving the toughness and plasticity of the material and reducing the risk of brittle fracture.

[0014] The slag-forming agent is further configured with a weight ratio of (0.05-0.15):1 of manganese ore, and the agent controls the furnace basicity at 0.65-0.75. The lime in the slag-forming agent is used to adjust the pH of the furnace charge, while fluorite is used to increase the slag fluidity. The ratio of the two can be adjusted according to actual needs, as long as the furnace basicity is controlled at 0.65-0.75. Suitable basicity helps form good slag, promotes the reduction reaction of manganese and silicon, and reduces the entry of impurity elements into the alloy product.

[0015] Further configuration involves the following power supply system for the electric furnace: during stable operation, the voltage is 180-220V, the current is 91000-10800A, and the resistance R=0.03±0.005Ω. 35-45 minutes before the molten alloy is discharged, the current is reduced to 10-15% of the stable operating current. During smelting, the furnace charge temperature is maintained at no lower than 1650℃. Voltage and current are primarily adjusted by controlling the resistance. After stable operation and current reduction, the resistance is controlled at R=0.03±0.005Ω. The electric furnace converts electrical energy into heat energy to melt the furnace charge and form a molten alloy. Other structures and supporting facilities of the electric furnace are the same as in existing technologies and will not be limited or elaborated upon here.

[0016] Further settings include a single ladle pouring time of 3-5 minutes and 3-4 pouring cycles. The ladle pouring operation is the same as in existing technologies, typically involving pouring the molten iron from the top pouring port. Pouring the ladle increases the contact area between the molten iron and oxygen, allowing the carbon in the molten iron to form carbon oxides, thus achieving decarburization and improving the Mn element recovery rate.

[0017] Further configuration: In S4, during casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy from one ladle is completed within 10-15 minutes. Discharging the molten alloy from the lower side during casting is because carbides, with their low density, float; discharging from the bottom reduces the carbon content of the product. During casting, the casting speed is carefully controlled, and slag on the surface of the molten alloy is grated into the ladle as much as possible. If slag is found in the mold, casting should be stopped, cleaned thoroughly, and then resumed. After casting, the product should be checked again for slag; if any is found, it should be cleaned promptly. The structure of the ladle that allows molten alloy to be discharged from the lower side is existing technology and will not be described in detail here.

[0018] The present invention provides a method for preparing low-carbon manganese-silicon alloy. This method utilizes manganese ore and silica to produce the alloy, with the manganese ore raw material requiring a relatively low manganese content. Precise batching controls the manganese and silicon content in the alloy, while smelting also controls the content of harmful elements such as carbon, phosphorus, and sulfur, resulting in a low-carbon, low-phosphorus, and low-sulfur product. Furthermore, the precise ratio of manganese ore, silica, and coke in the furnace charge prevents excessive carbon content in the alloy product. A slag-forming agent promotes the reduction reaction of manganese and silicon and reduces the entry of impurities into the alloy product. The resulting molten alloy undergoes a ladle-turning operation to achieve decarburization and improve Mn recovery. During casting, the casting speed is controlled, and the molten alloy is discharged from the lower side of the ladle, while slag is collected within the ladle. The coordinated steps and operations ensure stable product quality, allowing the alloy to be used as a later-stage additive in steel smelting to increase silicon or manganese levels. This can replace some or all of the metallic manganese, meeting the requirements for smelting ultra-low-carbon steel and reducing steel costs. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of the present invention.

[0020] The following examples use conventional instruments and equipment in the art. Unless otherwise specified, the experimental materials and reagents used in the following examples are commercially available and conform to conventional specifications in the art. Any techniques or conditions not specifically described in the following examples can be performed according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0021] It should be noted that, in this invention and the following embodiments, unless otherwise specified, concentration, ratio, etc. are all weight concentration, weight ratio, etc., "%" all represent weight percentage, and "parts" all represent weight parts. These are common writing habits used by those skilled in the art, and therefore will not be repeated in this invention.

[0022] As a preferred embodiment, the present invention provides a method for preparing a low-carbon manganese-silicon alloy, comprising the following steps: S1. Raw material pretreatment: Weigh manganese ore, silica, and coke in a weight ratio of 1:(0.35-0.45):(0.22-0.40), crush them separately, and then mix them evenly to form furnace charge; take lime and fluorite, crush them separately to a particle size of less than 20mm, and then mix them evenly to form slagging agent. The weight ratio of slagging agent to manganese ore is (0.05-0.15):1, and the slagging agent controls the alkalinity in the furnace at 0.65-0.75.

[0023] The manganese ore contains ≥38% Mn, with a particle size of 10-100mm, and no more than 10% of the particles are smaller than 10mm; the silica contains ≥97% SiO2, with a particle size of 10-100mm; and the coke contains ≥83.5% fixed carbon, ≤10% ash, and a particle size of 15-50mm.

[0024] S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 3-4 hours to form a molten alloy. The molten alloy in the furnace is then poured into a ladle. The tapping temperature of the molten alloy should not be lower than 1650℃. The power supply system of the electric furnace is as follows: During stable operation, the voltage is 180-220V, the current is 91000-10800A, and the resistance R=0.03±0.005Ω. 35-45 minutes before the molten alloy taps out, the current is reduced to 10-15% of the stable operating current. The voltage depends on the resistance and current.

[0025] S3. Ladle Transfer: The molten alloy is poured out of the furnace and into the ladle. The molten alloy is transferred in the ladle. The time for each transfer is 3-5 minutes, and the number of transfers is 3-4 times.

[0026] S4. Casting: After the ladle is poured, the molten alloy is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese-silicon alloy. During casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy of one ladle is completed within 10-15 minutes.

[0027] As a further improvement to the aforementioned implementation, during the process of pouring the molten alloy into the ladle, when the molten alloy has flowed into the ladle to 4 / 5 of its volume, rice husk ash is added along with the molten alloy, at a rate of 0.5-1 kg / t. Preferably, the SiO2 content in the rice husk ash is not less than 80%.

[0028] Rice husk ash contains a large amount of silicon dioxide, which has high chemical activity and is easily soluble. When rice husk ash is added to the alloy liquid during the pouring process, some of the silicon oxides in the rice husk ash react with the carbon in the alloy liquid under high temperature to generate silicon and carbon oxides. After the reaction, the silicon content in the alloy liquid increases and the carbon content decreases, making the removal of impurity elements—carbon—more thorough and without introducing new impurities. At the same time, rice husk ash has a porous structure and low thermal conductivity, which can adsorb carbides and phosphides in the alloy liquid and eventually mix them with the slag and be grated out. It also has a certain effect of blocking heat conduction after flowing to the surface of the alloy liquid, which helps to reduce the temperature drop during the pouring process. This improvement improves product quality and increases product added value, thereby improving the purity of alloy products and deep-processed steel.

[0029] Furthermore, the low-carbon manganese silicon alloy obtained by adding rice husk ash to the lamination process comprises the following components by mass fraction: Mn 58-63%, Si 27-30%, C 0.1-0.3%, P≤0.1%, S≤0.03%. The addition of rice husk ash to the lamination process increases the silicon content, decreases the carbon content, and slightly reduces the manganese content in the alloy product. The components and their contents in the alloy product approach those of a low-carbon manganese silicon alloy, resulting in a significant overall improvement in the quality of the low-carbon manganese silicon alloy.

[0030] The present invention will be further described in detail below with reference to embodiments. However, it should be understood that the embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Example 1

[0031] A method for preparing a low-carbon manganese-silicon alloy includes the following steps: S1. Raw material pretreatment: Manganese ore, silica, and coke are weighed in a weight ratio of 1:0.35:0.25, and after being crushed separately, they are mixed evenly to form furnace charge; lime and fluorite are taken, crushed to a particle size of less than 20mm, and then mixed evenly to form slagging agent. The weight ratio of slagging agent to manganese ore is 0.05:1, and the slagging agent controls the alkalinity in the furnace at 0.65.

[0032] The manganese ore contains ≥38% Mn, with a particle size of 10-100mm, and no more than 10% of the particles are smaller than 10mm; the silica contains ≥97% SiO2, with a particle size of 10-100mm; and the coke contains ≥83.5% fixed carbon, ≤10% ash, and a particle size of 15-50mm.

[0033] S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 3 hours to form a molten alloy. The molten alloy in the furnace is then poured into a ladle. The tapping temperature of the molten alloy is not lower than 1650℃. The power supply system of the electric furnace is as follows: during stable operation, the current is 91000A and the resistance R=0.03Ω. 35 minutes before the molten alloy taps out, the current is reduced to 10% of the stable operating current. The voltage depends on the resistance and current.

[0034] S3, Ladle Transfer: The molten alloy is poured out of the furnace and into the ladle. The molten alloy is transferred in the ladle. The time for each ladle transfer is 3 minutes, and the number of ladle transfers is 3.

[0035] S4. Casting: After the ladle is poured, the molten alloy is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese-silicon alloy. During casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy of one ladle is to be cast within 10 minutes. Example 2

[0036] A method for preparing a low-carbon manganese-silicon alloy includes the following steps: S1. Raw material pretreatment: Manganese ore, silica, and coke are weighed in a weight ratio of 1:0.45:0.40, and after being crushed separately, they are mixed evenly to form furnace charge; lime and fluorite are taken, crushed separately to a particle size of less than 20mm, and then mixed evenly to form slagging agent. The weight ratio of slagging agent to manganese ore is 0.15:1, and the slagging agent controls the alkalinity in the furnace at 0.75.

[0037] The manganese ore contains ≥38% Mn, with a particle size of 10-100mm, and no more than 10% of the particles are smaller than 10mm; the silica contains ≥97% SiO2, with a particle size of 10-100mm; and the coke contains ≥83.5% fixed carbon, ≤10% ash, and a particle size of 15-50mm.

[0038] S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 4 hours to form a molten alloy. Then, the molten alloy in the furnace is poured into a ladle. The tapping temperature of the molten alloy is not lower than 1650℃. The power supply system of the electric furnace is as follows: during stable operation, the current is 10800A and the resistance R=0.035Ω. 45 minutes before the molten alloy taps out, the current is reduced to 15% of the stable operating current. The voltage depends on the resistance and current.

[0039] S3. Ladle Transfer: The molten alloy is poured out of the furnace and into the ladle. The molten alloy is transferred in the ladle. The time for each ladle transfer is 5 minutes, and the number of ladle transfers is 4.

[0040] S4. Casting: After the ladle is poured, the molten alloy is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese-silicon alloy. During casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy of one ladle is to be cast within 15 minutes. Example 3

[0041] A method for preparing a low-carbon manganese-silicon alloy includes the following steps: S1. Raw material pretreatment: Manganese ore, silica, and coke are weighed in a weight ratio of 1:0.4:0.33, and after being crushed separately, they are mixed evenly to form furnace charge; lime and fluorite are taken, crushed separately to a particle size of less than 20mm, and then mixed evenly to form slagging agent. The weight ratio of slagging agent to manganese ore is 0.12:1, and the slagging agent controls the alkalinity in the furnace at 0.72.

[0042] The manganese ore contains ≥38% Mn, with a particle size of 10-100mm, and no more than 10% of the particles are smaller than 10mm; the silica contains ≥97% SiO2, with a particle size of 10-100mm; and the coke contains ≥83.5% fixed carbon, ≤10% ash, and a particle size of 15-50mm.

[0043] S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 3.5 hours to form a molten alloy. The molten alloy in the furnace is then poured into a ladle. The tapping temperature of the molten alloy is not lower than 1650℃. The power supply system of the electric furnace is as follows: during stable operation, the current is 10250A and the resistance R=0.03Ω. 40 minutes before the molten alloy taps out, the current is reduced to 13% of the stable operating current. The voltage depends on the resistance and current.

[0044] S3. Ladle Transfer: The molten alloy is poured out of the furnace and into the ladle. The molten alloy is transferred in the ladle. The time for each ladle transfer is 5 minutes, and the number of ladle transfers is 3.

[0045] S4. Casting: After the ladle is poured, the molten alloy is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese-silicon alloy. During casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy of one ladle is to be cast within 15 minutes. Example 4

[0046] A method for preparing a low-carbon manganese-silicon alloy includes the following steps: S1. Raw material pretreatment: Manganese ore, silica, and coke are weighed in a weight ratio of 1:0.4:0.33, and after being crushed separately, they are mixed evenly to form furnace charge; lime and fluorite are taken, crushed separately to a particle size of less than 20mm, and then mixed evenly to form slagging agent. The weight ratio of slagging agent to manganese ore is 0.12:1, and the slagging agent controls the alkalinity in the furnace at 0.72.

[0047] The manganese ore contains ≥38% Mn, with a particle size of 10-100mm, and no more than 10% of the particles are smaller than 10mm; the silica contains ≥97% SiO2, with a particle size of 10-100mm; and the coke contains ≥83.5% fixed carbon, ≤10% ash, and a particle size of 15-50mm.

[0048] S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 3.5 hours to form a molten alloy. The molten alloy in the furnace is then poured into a ladle. The tapping temperature of the molten alloy is not lower than 1650℃. The power supply system of the electric furnace is as follows: during stable operation, the current is 10250A and the resistance R=0.03Ω. 40 minutes before the molten alloy taps out, the current is reduced to 13% of the stable operating current. The voltage depends on the resistance and current.

[0049] S3. Ladle Transfer: The molten alloy is discharged from the furnace and transferred into a ladle. The alloy is then transferred within the ladle; each transfer takes 5 minutes, and the number of transfers is 3. During the discharge and ladle transfer process, when the molten alloy has filled 4 / 5 of the ladle volume, rice husk ash is added to the ladle along with the alloy at a rate of 1 kg / t. The SiO2 content of the rice husk ash must be no less than 80%.

[0050] S4. Casting: After the ladle is poured, the molten alloy is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese-silicon alloy. During casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy of one ladle is to be cast within 15 minutes.

[0051] The low-carbon manganese-silicon alloy products prepared in each example were tested for their chemical composition using the methods in GB / T4008-2024 "Manganese-Silicon Alloys". Each test sample was tested in triplicate, and the average value was taken. The results are shown in Table 1.

[0052] Table 1 (Unit: %)

[0053] As shown in the table above, the low-carbon manganese-silicon alloy products in each embodiment are of excellent quality. The silicon, carbon, phosphorus, and sulfur contents meet the requirements of FeMn64Si25, indicating superior quality. In Example 4, after improving the preparation method, the carbon and phosphorus contents of the resulting low-carbon manganese-silicon alloy product decreased, while the silicon content increased. Although the manganese content was slightly reduced due to component ratios, the overall product quality was improved. The silicon, carbon, phosphorus, and sulfur contents met the requirements of micro-carbon manganese-silicon alloys, further broadening the product's application range. This improved the purity of the alloy products and deep-processed steel, increasing the product's added value.

[0054] It should be noted that some detailed steps of the operation are not described in this invention, but are prior art known to those skilled in the art, and therefore will not be repeated here. Furthermore, in this invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible secondary ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0055] It should be noted that the detailed structure of some devices is not described in this invention, but is prior art known to those skilled in the art, and therefore will not be elaborated here. In this invention, structures and devices not specifically limited can be purchased commercially, and those skilled in the art only need to install and operate them according to the accompanying instruction manual, without requiring any creative effort from those skilled in the art.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. In this invention, not all possible combinations of the various technical features in each embodiment or implementation are described. As long as the combinations of these technical features do not contradict each other, the various technical features in each embodiment or implementation can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 method for preparing a low-carbon manganese-silicon alloy, characterized in that, include: S1. Raw material pretreatment: Weigh manganese ore, silica, and coke according to the proportion, crush them separately, and then mix them evenly to form furnace charge; take lime and fluorite, crush them separately to a particle size of less than 20mm, and then mix them evenly to form slagging agent; S2. Smelting: The furnace charge and slag-forming agent are fed into the electric furnace together and smelted for 3-4 hours to form an alloy liquid. Then the molten alloy liquid in the furnace is poured into the ladle. The furnace outlet temperature of the alloy liquid is not lower than 1650℃. S3, Ladle Transfer: The molten alloy in the furnace is poured out and sent into the ladle, and the molten alloy is transferred in the ladle. S4. Casting: After the pouring is completed, the alloy liquid is poured into the mold, cooled and solidified to form a billet, thus obtaining the low-carbon manganese silicon alloy.

2. The method for preparing low-carbon manganese-silicon alloy according to claim 1, characterized in that, The weight ratio of manganese ore, silica, and coke in the furnace charge is 1:(0.35-0.45):(0.22-0.40).

3. The method for preparing low-carbon manganese-silicon alloy according to claim 1, characterized in that, The manganese ore contains ≥38% Mn, has a particle size of 10-100mm, and has no more than 10% particles smaller than 10mm; the silica contains ≥97% SiO2, has a particle size of 10-100mm; and the coke contains ≥83.5% fixed carbon, ≤10% ash, and has a particle size of 15-50mm.

4. The method for preparing the low-carbon manganese-silicon alloy according to claim 1, characterized in that, The weight ratio of the slag-forming agent to manganese ore is (0.05-0.15):1, and the slag-forming agent controls the alkalinity in the furnace at 0.65-0.

75.

5. The method for preparing low-carbon manganese-silicon alloy according to claim 1, characterized in that, The power supply system of the electric furnace is as follows: when operating stably, the voltage is 180-220V, the current is 91000-10800A, and the resistance is R=0.03±0.005Ω.

6. The method for preparing the low-carbon manganese-silicon alloy according to claim 5, characterized in that, 35-45 minutes before the alloy liquid is discharged from the furnace, the current is reduced to 10-15% of the current during stable operation.

7. The method for preparing low-carbon manganese-silicon alloy according to claim 1, characterized in that, The single package transfer time is 3-5 minutes, and the number of package transfers is 3-4 times.

8. The method for preparing low-carbon manganese-silicon alloy according to claim 1, characterized in that, In step S4, during casting, the molten alloy is discharged from the lower side of the ladle, and the slag is grated inside the ladle. The molten alloy of one ladle is completed within 10-15 minutes.

9. The method for preparing the low-carbon manganese-silicon alloy according to any one of claims 1-8, characterized in that, The low-carbon manganese silicon alloy comprises the following components by mass fraction: Mn 60-65%, Si 25-27%, C 0.2-0.3%, P≤0.15%, S≤0.03%.

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