Preparation method of carbon ferrochrome in oxygen blowing refining

Abstract

The invention discloses a preparation method of medium-carbon ferrochrome in oxygen blowing refining, relates to the technical field of ferroalloy smelting, can solve the problems that a traditional processing technology needs to consume a large amount of electric energy and can discharge a large amount of carbon dioxide, and realizes processing treatment of high-carbon ferrochrome by using a method of replacing electricity with oxygen by using processing steps of S1-S2-S3-S4. The oxygen blowing refining process in the converter is utilized, the carbon content in the ferrochrome can be effectively reduced, meanwhile, redundant impurities such as silicon and sulfur can be removed in the refining process, the purity of the ferrochrome is remarkably improved, the oxygen blowing refining technology of replacing electricity with oxygen is adopted, oxygen can react with carbon in high-carbon ferrochrome to generate carbon dioxide gas, and the purity of the ferrochrome is improved. Therefore, the carbon content in the ferrochrome is effectively removed, the carbon content is controlled within the range of medium-carbon ferrochrome, the influence of too high carbon content on subsequent processing and use performance is avoided, the production capacity and stability of a converter can be improved to a certain extent, energy waste is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ferroalloy smelting, and in particular to a method for preparing medium-carbon ferrochrome by oxygen blowing refining. Background Art

[0002] Medium carbon ferrochrome (FeCr) is a type of chromium alloy, which is widely used in the steel industry, mainly for the production of stainless steel and other corrosion-resistant alloys. Its main components are iron (Fe) and chromium (Cr), of which the chromium content is usually between 60% and 70%. The addition of chromium can significantly improve the hardness, wear resistance and corrosion resistance of the alloy, so medium carbon ferrochrome plays a vital role in the manufacture of stainless steel. The production of medium carbon ferrochrome is usually obtained by the reduction reaction of chromium ore and coke in a submerged arc furnace. With the development of industrial technology, the demand for medium carbon ferrochrome continues to grow.

[0003] However, in the traditional medium-carbon ferrochrome production process, the "three-step method" process can produce low-carbon high-quality products, but it consumes a lot of energy and has low resource utilization efficiency, which brings a significant environmental burden. First, in the production process, it usually takes more than 11,000 kWh of electricity to achieve the required quality standards, and its power loss. In addition, the electric heating method will inevitably emit a large amount of carbon dioxide, further exacerbating the release of greenhouse gases. Summary of the invention

[0004] In order to solve the problem that the traditional processing technology in the prior art consumes a lot of electricity and emits a lot of carbon dioxide, the present application provides a method for preparing medium-carbon ferrochrome by oxygen blowing refining to solve the above problems.

[0005] In order to achieve the above purpose, the technical solution adopted in this application is:

[0006] A method for preparing medium-carbon ferrochrome by oxygen blowing refining comprises the following steps:

[0007] S1. Prepare raw materials: add chromite ore, coke, silica and electrode paste into a submerged arc furnace for smelting to obtain high carbon ferrochrome water with a chromium content greater than 50%;

[0008] The materials, by weight percentage, include 75% chromite ore, 19% coke, 4.7% silica and 1.3% electrode paste.

[0009] S2. Converter refining: high carbon ferrochrome water and reducing agent are added into the converter, and the furnace body of the converter is heated by the combustion of the reducing agent. When the temperature in the converter rises to 1400℃-1900℃, oxygen is blown into the converter through the oxygen blowing device. After the reaction is completed, ferrochrome alloy is obtained.

[0010] S3. Melting and casting medium carbon ferrochrome: the ferrochrome alloy is transferred into an ore-melting furnace, and the temperature inside the ore-melting furnace is controlled at 1500°C-1700°C, and then smelting is performed; after smelting is completed, when the temperature inside the ore-melting furnace is controlled at 1400°C-1700°C, pouring is performed; after pouring is completed, the ferrochrome alloy enters a cooling stage, and after cooling, a ferrochrome ingot is obtained.

[0011] S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing treatments to obtain medium carbon ferrochrome.

[0012] As a further improvement of the present invention, in the step S1, first, the chromite ore needs to be crushed and ground, the chromite ore is crushed into particles, and then added to the electric arc furnace, silica is used as a flux, the particle size entering the furnace is 10mm-80mm, and the electrode paste adopts a closed paste, and the size entering the furnace is 50-150mm.

[0013] As a further improvement of the present invention, in the step S2, the chromium content in the high carbon chromium iron water is higher than 60%, the silicon content is lower than 1.5%, and the sulfur content is less than 0.036%.

[0014] As a further improvement of the present invention, in the step S2, the reducing agent is coke, and when the temperature in the converter rises to 1500°C-1800°C, oxygen is blown into the converter through an oxygen blowing device.

[0015] As a further improvement of the present invention, in the step S2, the oxygen flow rate of the oxygen blowing device during the oxygen blowing process is generally 10,000 Nm 3 / h to 20,000Nm 3 / h, and the pressure is generally between 0.5Mpa and 2.0Mpa.

[0016] As a further improvement of the present invention, in the S2 step, the oxygen blowing device performs blowing through an oxygen lance cooled by high-pressure water, and the distance between the nozzle and the liquid surface is 400mm-600mm. When the amount of high-carbon chromium iron water charged is small and the molten pool depth is shallow, a high lance position is selected, and when the amount of high-carbon chromium iron water charged is large and the molten pool depth is deep, a low lance position is selected.

[0017] As a further improvement of the present invention, in the step S2, the silicon content of the high carbon chromium iron water entering the furnace is controlled to be above 0.5%, and the oxygen blowing time is controlled to be 8 min-12 min.

[0018] As a further improvement of the present invention, in the step S3, the temperature inside the submerged arc furnace is controlled at 1550°C-1650°C, and then smelting is carried out; after smelting is completed, when the temperature inside the submerged arc furnace is controlled at 1500°C-1600°C, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process.

[0019] As a further improvement of the present invention, in the step S4, the deep processing method is any one of static water quenching, dynamic water quenching or tempering.

[0020] Compared with the prior art, the technical solution provided by the present invention has the following advantages and effects:

[0021] 1. In the present application, high carbon ferrochrome is processed by the method of "replacing electricity with oxygen". The oxygen blowing refining process in the converter can effectively reduce the carbon content in the ferrochrome alloy. At the same time, excess impurities such as silicon and sulfur can be removed during the refining process, and finally medium carbon ferrochrome is obtained.

[0022] 2. In the present application, by controlling parameters such as oxygen flow rate, oxygen blowing time and temperature during the oxygen blowing refining process, various impurities in high carbon ferrochrome, including unfavorable components such as silicon and sulfur, can be effectively removed, and the purity of the ferrochrome alloy is significantly improved, making it more in line with the requirements of medium carbon ferrochrome. In addition, the oxygen blowing refining technology of "replacing electricity with oxygen" can also be used to react oxygen with carbon in high carbon ferrochrome to generate carbon dioxide gas, thereby effectively removing the carbon content in the ferrochrome, controlling the carbon content within the range of medium carbon ferrochrome, and avoiding the influence of excessive carbon content on subsequent processing and use performance.

[0023] 3. In the present application, the production cycle can be shortened and energy consumption can be reduced by precisely controlling the refining treatment and smelting process of high carbon ferrochrome. In particular, efficient oxygen blowing refining of the converter by an oxygen blowing device not only helps to improve the quality of ferrochrome alloy, but also can improve the production capacity and stability of the converter to a certain extent. In particular, reasonable temperature control and alloy stirring technology are used in the oxygen blowing process and the smelting process of the submerged arc furnace, which can further reduce energy waste and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 is a flow chart of the preparation method of the present invention;

[0026] Figure 2 It is a flow chart of the liquid oxygen supply system in step S2 of the present invention. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] Example 1 and step explanation:

[0029] A method for preparing medium-carbon ferrochrome by oxygen blowing refining comprises the following steps:

[0030] S1. Prepare raw materials: first crush 75% of chromite ore, and when it is crushed into particles, add 75% of chromite ore particles, 19% of coke, 4.7% of silica and 1.3% of electrode paste into a submerged arc furnace for smelting, wherein the silica particle size entering the furnace is 10mm-80mm, and the electrode paste is a closed paste with a size of 50-150mm entering the furnace, to obtain high-carbon ferrochrome water with a chromium content greater than 50%.

[0031] It is explained that the ore-heating furnace uses a 16,800 kVA model and is fully enclosed. While crushing the chromite ore, it is also necessary to carry out magnetic separation and flotation processes on the chromite ore to obtain iron ore with higher purity. The chromite ore is selected as dry and pure lump ore or concentrate powder, and the higher the Cr2O3 content, the better, and the lower the impurity content, the better. The phosphorus content in the chromite should not be greater than 0.03%, the particle size is less than 60mm, and the particle size of silicon-chromium alloy is less than 30mm.

[0032] Specifically, during the melting process, chromium and iron will dissolve each other, iron will sink to the bottom of the molten pool, and chromium will float on the surface to form a layer of slag. After the slag is formed, it is necessary to treat the slag. First, the slag is extracted from the molten pool, and then the slag is cooled, crushed, beneficiated and other treatment processes are carried out to separate high-purity chromium and other useful elements. At the same time, the slag can also be recycled. After the slag treatment, the chromium obtained can be used to prepare high-carbon ferrochrome. The separated chromium is added to the furnace pool, and then an appropriate amount of high-purity iron ore is added. After smelting and slag treatment, high-carbon ferrochrome with a chromium content of more than 50% is finally obtained.

[0033] S2. Converter refining: adding high carbon molten chromium with a chromium content greater than 50% and coke into a converter, and raising the temperature inside the converter to 1400°C-1900°C by burning the coke. Then, using a top-blown converter method, oxygen is blown into the converter through an oxygen blowing device, wherein the oxygen blowing time is controlled at 8min-12min. After the reaction is completed, a ferrochrome alloy is obtained.

[0034] It is explained that the oxygen blown into the converter by the oxygen blowing device is gaseous oxygen. The conversion process of gaseous oxygen is as follows: after the liquid oxygen is delivered to the factory by the transportation unit in a cryogenic liquid tank truck, it is filled into the liquid oxygen storage tank by gravity. The maximum pressure of the storage tank is 2.3Mpa. It is pressurized to about 2.0Mpa by a cryogenic liquid pump, and then enters the buffer tank after being vaporized by the vaporizer. After that, it enters the delivery pipeline through the stabilizer, and then is connected to the high-pressure water-cooled oxygen gun through the delivery pipeline, and then the inside of the converter is blown. In the process of oxygen blowing, the oxygen flow rate is usually 10.000Nm 3 / h to 20.000Nm 3 / h, and the pressure is generally between 0.5Mpa and 2.0Mpa.

[0035] Specifically, after adding high-carbon chromium molten iron to the converter, shake the furnace body straight, lower the oxygen lance that has been cooled by high-pressure water for blowing, make the nozzle 400mm-600mm away from the liquid surface, and start blowing oxygen. Among them, when the amount of molten iron charged is small and the depth of the molten pool is shallow, choose a high lance position. When the amount of molten iron charged is large and the depth of the molten pool is deep, choose a low lance position. Since a large amount of elements are oxidized to form natural slag with a high SiO2 content in the early stage of blowing, slag-making materials should be added after about 4 minutes of blowing to protect the furnace lining and prepare for the addition of reducing agents to reduce chromium oxide later. The large amount of CO gas produced by the decarburization reaction makes the flame gradually fade from dark red to longer and brighter. As the carbon concentration in the ferrochrome decreases, the decarburization speed slows down, chromium begins to be gradually oxidized, and the flame at the furnace mouth shrinks. At this time, the end point should be controlled, and the blowing of iron should be stopped after the carbon concentration is determined to be qualified.

[0036] It is worth mentioning that before tapping, if the fluidity of the converter slag deteriorates, a small amount of ferrochrome can be added to the furnace for pre-reduction to reduce the Cr2O3 content and slag basicity in the slag and increase the fluidity of the slag. When tapping, silicon-chromium alloy should be added to the ladle built with magnesia bricks to reduce the chromium in the slag, so that the Cr2O3 in the final slag is controlled below 27%, and the CaO / SiO2 is below 0.5, to ensure that 100% of the slag is returned for reuse.

[0037] S3. Melting and casting medium carbon ferrochrome: control the temperature of the submerged arc furnace at 1550℃-1650℃, add ferrochrome alloy for smelting, and after smelting, when the temperature inside the submerged arc furnace is controlled at 1500℃-1600℃, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process. After pouring, the ferrochrome alloy enters the cooling stage, and the cooling process should be uniform to avoid cracks or other uneven structures in the alloy.

[0038] It is explained that in the smelting process of ferrochrome alloy, effective stirring of the melt is very important for promoting the uniformity of the alloy, removing impurities and improving fluidity. The stirring can be carried out by an air stirring system or oxygen stirring or electromagnetic stirring or mechanical stirring device to promote the homogenization of the material: ensuring that the chromium, iron and other elements of the ferrochrome alloy are evenly distributed.

[0039] S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing by any one of deep static water quenching, dynamic water quenching or tempering to obtain medium carbon ferrochrome.

[0040] It is explained that through the static water quenching treatment method, the ferrochrome alloy can be quickly immersed in water at high temperature to quickly reduce the temperature, thereby changing its microstructure and improving the hardness and strength of the material; through the dynamic water quenching treatment method, the ferrochrome alloy can be quickly cooled by flowing water or spraying after being heated, which can more evenly improve its mechanical properties; through the tempering treatment method, the ferrochrome alloy can be heated to a certain temperature and maintained for a certain time after water quenching to remove the internal stress in the alloy and improve its toughness and ductility.

[0041] Embodiment 2:

[0042] A method for preparing medium-carbon ferrochrome by oxygen blowing refining comprises the following steps:

[0043] S1. Prepare raw materials: first crush 75% of chromite ore, and when it is crushed into particles, add 75% of chromite ore particles, 19% of coke, 4.7% of silica and 1.3% of electrode paste into a submerged arc furnace for smelting, wherein the silica particle size entering the furnace is 10 mm, and the electrode paste is a closed paste with a furnace size of 50 mm, to obtain high-carbon ferrochrome water with a chromium content greater than 50%.

[0044] S2. Converter refining: Add high carbon molten chromium with a chromium content greater than 50% and coke into the converter. When the temperature inside the converter is raised to 1450°C-1850°C by the combustion of coke, use the top-blown converter method and blow oxygen into the converter through an oxygen lance cooled by high pressure water in the oxygen blowing device. During the oxygen blowing process, the oxygen lance nozzle is 400mm away from the liquid surface and the oxygen flow rate is 10.000Nm 3 / h, the pressure is 0.5Mpa and the oxygen blowing time is controlled at 8min, and after the reaction is completed, ferrochrome alloy is obtained.

[0045] S3. Melting and casting medium carbon ferrochrome: control the temperature of the submerged arc furnace at 1550℃-1650℃, add ferrochrome alloy for smelting, and after smelting, when the temperature inside the submerged arc furnace is controlled at 1500℃-1600℃, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process. After pouring, the ferrochrome alloy enters the cooling stage, and the cooling process should be uniform to avoid cracks or other uneven structures in the alloy.

[0046] S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing by any one of deep static water quenching, dynamic water quenching or tempering to obtain medium carbon ferrochrome.

[0047] Embodiment 3:

[0048] A method for preparing medium-carbon ferrochrome by oxygen blowing refining comprises the following steps:

[0049] S1. Prepare raw materials: first crush 75% of chromite ore, and when it is crushed into particles, add 75% of chromite ore particles, 19% of coke, 4.7% of silica and 1.3% of electrode paste into a submerged arc furnace for smelting, wherein the silica particle size entering the furnace is 80mm, and the electrode paste is a closed paste with a furnace size of 150mm, to obtain high-carbon ferrochrome water with a chromium content greater than 50%.

[0050] S2. Converter refining: Add high carbon molten chromium with a chromium content greater than 50% and coke into the converter. When the temperature inside the converter is raised to 1500°C-1800°C by the combustion of coke, use the top-blown converter method and blow oxygen into the converter through an oxygen lance cooled by high pressure water in the oxygen blowing device. During the oxygen blowing process, the oxygen lance nozzle is 600mm away from the liquid surface and the oxygen flow rate is 2.000Nm 3 / h, the pressure is 2Mpa and the oxygen blowing time is controlled at 12min, and after the reaction is completed, ferrochrome alloy is obtained.

[0051] S3. Melting and casting medium carbon ferrochrome: control the temperature of the submerged arc furnace at 1550℃-1600℃, add ferrochrome alloy for smelting, and after smelting, when the temperature inside the submerged arc furnace is controlled at 1500℃-1600℃, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process. After pouring, the ferrochrome alloy enters the cooling stage, and the cooling process should be uniform to avoid cracks or other uneven structures in the alloy.

[0052] S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing by any one of deep static water quenching, dynamic water quenching or tempering to obtain medium carbon ferrochrome.

[0053] Embodiment 4:

[0054] A method for preparing medium-carbon ferrochrome by oxygen blowing refining comprises the following steps:

[0055] S1. Prepare raw materials: first crush 75% of chromite ore, and when it is crushed into particles, add 75% of chromite ore particles, 19% of coke, 4.7% of silica and 1.3% of electrode paste into a submerged arc furnace for smelting, wherein the silica particle size entering the furnace is 40 mm, and the electrode paste is a closed paste with a furnace size of 80 mm, to obtain high-carbon ferrochrome water with a chromium content greater than 50%.

[0056] S2. Converter refining: Add high carbon molten chromium with a chromium content greater than 50% and coke into the converter. When the temperature inside the converter is raised to 1600°C-1700°C by the combustion of coke, oxygen is blown into the converter by a top-blown converter method through an oxygen lance cooled by high pressure water in the oxygen blowing device. During the oxygen blowing process, the oxygen lance nozzle is 500mm away from the liquid surface and the oxygen flow rate is 13.000Nm 3 / h, the pressure is 1Mpa and the oxygen blowing time is controlled at 10min, and after the reaction is completed, ferrochrome alloy is obtained.

[0057] S3. Melting and casting medium carbon ferrochrome: control the temperature of the submerged arc furnace at 1600℃-1650℃, add ferrochrome alloy for smelting, and after smelting, when the temperature inside the submerged arc furnace is controlled at 1500℃-1600℃, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process. After pouring, the ferrochrome alloy enters the cooling stage, and the cooling process should be uniform to avoid cracks or other uneven structures in the alloy.

[0058] S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing by any one of deep static water quenching, dynamic water quenching or tempering to obtain medium carbon ferrochrome.

[0059] Embodiment 5:

[0060] A method for preparing medium-carbon ferrochrome by oxygen blowing refining comprises the following steps:

[0061] S1. Prepare raw materials: first crush 75% of chromite ore, and when it is crushed into particles, add 75% of chromite ore particles, 19% of coke, 4.7% of silica and 1.3% of electrode paste into a submerged arc furnace for smelting, wherein the silica particle size entering the furnace is 60 mm, and the electrode paste is a closed paste with a furnace size of 120 mm, to obtain high-carbon ferrochrome water with a chromium content greater than 50%.

[0062] S2. Converter refining: Add high carbon molten chromium with a chromium content greater than 50% and coke into the converter. When the temperature inside the converter is raised to 1650°C-1700°C by the combustion of coke, oxygen is blown into the converter by a top-blown converter method through an oxygen lance cooled by high pressure water in the oxygen blowing device. During the oxygen blowing process, the oxygen lance nozzle is 550mm away from the liquid surface and the oxygen flow rate is 17.000Nm 3 / h, the pressure is 1.5Mpa and the oxygen blowing time is controlled at 10min, and after the reaction is completed, ferrochrome alloy is obtained.

[0063] S3. Melting and casting medium carbon ferrochrome: control the temperature of the submerged arc furnace at 1600℃-1650℃, add ferrochrome alloy for smelting, and after smelting, when the temperature inside the submerged arc furnace is controlled at 1500℃-1600℃, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process. After pouring, the ferrochrome alloy enters the cooling stage, and the cooling process should be uniform to avoid cracks or other uneven structures in the alloy.

[0064] S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing by any one of deep static water quenching, dynamic water quenching or tempering to obtain medium carbon ferrochrome.

[0065] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing medium carbon ferrochrome by oxygen blowing refining, characterized in that: The following steps are involved: S1. Prepare raw materials: add chromite ore, coke, silica and electrode paste into a submerged arc furnace for smelting to obtain high carbon ferrochrome water with a chromium content greater than 50%; The materials, by weight percentage, include 75% chromite ore, 19% coke, 4.7% silica and 1.3% electrode paste. S2. Converter refining: high carbon ferrochrome water and reducing agent are added into the converter, and the furnace body of the converter is heated by the combustion of the reducing agent. When the temperature in the converter rises to 1400℃-1900℃, oxygen is blown into the converter through the oxygen blowing device. After the reaction is completed, ferrochrome alloy is obtained. S3. Melting and casting medium carbon ferrochrome: the ferrochrome alloy is transferred into an ore-melting furnace, and the temperature inside the ore-melting furnace is controlled at 1500°C-1700°C, and then smelting is performed; after smelting is completed, when the temperature inside the ore-melting furnace is controlled at 1400°C-1700°C, pouring is performed; after pouring is completed, the ferrochrome alloy enters a cooling stage, and after cooling, a ferrochrome ingot is obtained. S4. Deep processing: The ferrochrome ingot is subjected to multiple deep processing treatments to obtain medium carbon ferrochrome.

2. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 1, characterized in that: In the step S1, first, the chromite ore needs to be crushed and ground, the chromite ore is crushed into particles, and then added into the submerged arc furnace, silica is used as a flux, the particle size entering the furnace is 10mm-80mm, and the electrode paste adopts a closed paste, and the size entering the furnace is 50-150mm.

3. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 2, characterized in that: In the step S2, the chromium content in the high carbon chromium iron water is higher than 60%, the silicon content is lower than 1.5%, and the sulfur content is less than 0.036%.

4. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 3, characterized in that: In the step S2, the reducing agent is coke, and when the temperature in the converter rises to 1500°C-1800°C, oxygen is blown into the converter through an oxygen blowing device.

5. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 4, characterized in that: In the step S2, the oxygen flow rate of the oxygen blowing device is usually 10,000 Nm 3 / h to 20,000Nm 3 / h, and the pressure is generally between 0.5Mpa and 2.0Mpa.

6. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 5, characterized in that: In the step S2, the oxygen blowing device performs blowing through an oxygen lance cooled by high-pressure water, and the distance between the nozzle and the liquid surface is 400mm-600mm. When the amount of high-carbon ferrochrome water charged is small and the molten pool depth is shallow, a high lance position is selected, and when the amount of high-carbon ferrochrome water charged is large and the molten pool depth is deep, a low lance position is selected.

7. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 6, characterized in that: In the step S2, the silicon content of the high carbon chromium iron water entering the furnace is controlled to be above 0.5%, and the oxygen blowing time is controlled to be 8 min-12 min.

8. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 7, characterized in that: In the step S3, the temperature inside the submerged arc furnace is controlled at 1550°C-1650°C, and then smelting is carried out; after smelting is completed, when the temperature inside the submerged arc furnace is controlled at 1500°C-1600°C, pouring is carried out, and the ferrochrome alloy is stirred during the smelting and pouring process.

9. The method for preparing medium carbon ferrochrome by oxygen blowing refining according to claim 8, characterized in that: In the step S4, the deep processing method is any one of static water quenching, dynamic water quenching or tempering.

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