Production method of micro-carbon ferrochrome powder

Abstract

The invention provides a production method of micro-carbon ferrochrome powder. Comprising the steps of raw material pretreatment, raw material mixing, reducing agent selection and addition, reduction reaction furnace design, reduction reaction, metal separation, metal powder preparation, alloying reaction and powder screening and grading. And packaging and storing the powder. And through accurate raw material mixing and reducing agent adding, the efficiency and completeness of the reduction reaction are improved, and metal loss is reduced. And through the application of calculus and a statistical formula, the reaction conditions and the powder particle size distribution are optimized, and the uniformity and consistency of the product are improved. By means of damp-proof packaging and inert gas protection measures, the powder is effectively prevented from being oxidized and affected with damp in the storage process, and the shelf life of the product is prolonged.

Description

Technical Field

[0001] The present invention specifically relates to a method for producing micro-carbon ferrochrome powder. Background Art

[0002] Micro-carbon ferrochrome powder is a chromium-containing ferroalloy. It is obtained by electric furnace smelting using chromite, lime, and crushed coke as raw materials. It is mainly used as an alloying element additive for smelting chromium steel and nickel-chromium steel, and can also be used as a deoxidizer for smelting chromium steel. In the existing production methods of micro-carbon ferrochrome powder, the efficiency and completeness of the reduction reaction are not high, resulting in waste of raw materials. At the same time, due to the lack of detailed requirements for reaction conditions and raw material selection in the existing methods, there are certain problems with the uniformity and consistency of the products. Therefore, a method for producing micro-carbon ferrochrome powder is proposed to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for producing micro-carbon ferrochrome powder in view of the deficiencies of the prior art, which can well solve the above problems.

[0004] To meet the above requirements, the technical solution adopted by the present invention is: to provide a method for producing micro-carbon ferrochrome powder, which includes the following steps:

[0005] S1: Perform the operation of raw material pretreatment. Select high-purity chromite and iron ore; use a jaw crusher to crush the ore to a particle size less than 5 mm. During the crushing process, control the feeding speed and crushing pressure to avoid over-crushing; pass the crushed ore through a dry magnetic separator with a magnetic field intensity set at 0.8 - 1.2 T to remove magnetic impurities; send the magnetically separated ore into a ball mill, control the ball mill speed at 25 - 30 rpm, use high-chromium steel balls as the grinding medium, and grind for 2 hours to ensure that the particle size reaches below 100 mesh; send the finely ground ore slurry into a flotation machine, add a collector and a frother, and control the pH value at 8 - 9 to remove non-metallic impurities;

[0006] S2: Perform the operation of raw material mixing. Calculate the mass ratio of chromite and iron ore according to the composition of the target product; use a double-shaft stirring mixer, control the stirring speed at 20 - 25 rpm, and mix for 30 minutes; randomly sample from the mixed material and use an X-ray fluorescence spectrometer to detect the contents of Cr and Fe to ensure uniform mixing;

[0007] S3: Perform the steps of selecting and adding a reducing agent. Select coke with a fixed carbon content ≥ 85%, an ash content ≤ 10%, and a volatile content ≤ 5%; crush the coke to a particle size less than 3 mm, use a vibrating screen for screening to ensure uniform particle size distribution; add coke at 15% of the weight of the mixed ore; put the coke and the mixed ore into the double-shaft stirring mixer again, with a stirring speed of 20 rpm and a mixing time of 15 minutes;

[0008] S4: Steps for the design of the reduction reactor. The reduction reactor is designed as a three-stage reduction furnace with a high-aluminum refractory lining for the furnace chamber and a thermal insulation layer provided outside the furnace body; the temperature of the preheating zone is 800 °C, the temperature of the reduction zone is 1450 °C, the cooling zone adopts a water-cooling system, and the cooling rate is controlled at 50 °C / min; silicon molybdenum rod heating elements are used with a power density of 10 kW / m 2 , and the temperature control accuracy is ±5 °C; nitrogen is introduced into the reduction zone with a flow rate controlled at 10 L / min to prevent metal oxidation;

[0009] S5: Conduct the reduction reaction. Load the mixed raw materials and reducing agent into the reduction furnace, and control the loading density at 1.5 - 2.0 g / cm 3 ; Start the heating system with a heating rate of 10 °C / min in the preheating zone and 15 °C / min in the reduction zone; use a thermocouple to monitor the temperature inside the furnace in real time and use a gas analyzer to detect the concentrations of carbon monoxide and carbon dioxide; when the concentration of carbon monoxide drops below 0.1%, it is determined that the reaction is complete;

[0010] In the above reaction, the reaction time and temperature satisfy the following dynamic model:

[0011]

[0012] Where:

[0013] T(x,t): The temperature distribution function at position x and time t inside the furnace, where x is the spatial coordinate inside the furnace and t is the time coordinate;

[0014] α: Thermal diffusivity, unit: m 2 / s, representing the heat diffusion ability inside the furnace, k is the thermal conductivity, unit: W / m·K; ρ is the material density, unit: kg / m 3 ; c p is the specific heat capacity. Unit: J / kg·K;

[0015] Q: Reaction heat, unit: J / mol, representing the heat released by the reduction reaction;

[0016] r(C,T): Reaction rate function, unit: mol / m 3 ·s, representing the influence of reactant concentration and temperature on the reaction rate, C: Reactant concentration, unit: mol / m 3 ; n: Reaction order, representing the influence degree of reactant concentration on the reaction rate;

[0017] k0: Pre-exponential factor, unit: mol 1-n / m 3(1-n) ·S, representing the reference value of the reaction rate;

[0018] E a : Activation energy, unit: J / mol, representing the energy threshold required for the reaction;

[0019] R: Ideal gas constant;

[0020] Rate of change of temperature with time, unit: K / s;

[0021] Second-order partial derivative of temperature in space, unit: K / m 2 , representing the change of temperature gradient;

[0022] S6: Step of performing metal separation. Pour the reduced material into a centrifuge, and control the rotation speed at 1000 - 1200 rpm; utilize the density difference between chromium and iron metals, with a separation time of 10 minutes; collect the metallic iron deposited at the bottom and metallic chromium at the upper part respectively;

[0023] S7: Process of performing metal powder preparation. Put the separated metallic chromium and iron into a ball mill respectively, with the rotation speed of the ball mill at 30 rpm and the grinding time of 4 hours; introduce nitrogen during the ball milling process, with a flow rate of 5 L / min, to prevent the oxidation of metal powder; use a laser particle size analyzer to detect the particle size of the powder, ensuring that the particle size reaches below 10 microns;

[0024] S8: Step of performing alloying reaction. Mix the chromium powder and iron powder in proportion, use a V-type mixer, with a mixing time of 20 minutes; put the mixed powder into a vacuum induction furnace, heat it to 1600 °C, with a heating rate of 20 °C / min; keep it at 1600 °C for heat preservation to fully alloy chromium and iron, then turn off the heating system and let the furnace cool naturally to room temperature;

[0025] S9: Step of performing powder screening and classification. Pass the alloyed ferrochromium powder through a vibrating screen with mesh apertures of 50 μm, 20 μm, and 10 μm respectively, and classify the powder into coarse powder, medium powder, and fine powder; use a laser particle size analyzer to detect the particle size distribution of each grade of powder;

[0026] S10: Step of performing powder packaging and storage. Pack the screened ferrochromium powder into an aluminum foil bag, fill it with argon and then seal it, and store the packaged powder in a dry and cool warehouse, with the relative humidity controlled below 30%.

[0027] Preferably, in step S1, the content of Cr2O3 in the chromite ore is ≥ 45%, and the content of Fe2O3 in the iron ore is ≥ 60%.

[0028] Preferably, the collector in step S1 is sodium oleate, and the frother is pine oil.

[0029] Preferably, the dynamic model during the heating-up and heat preservation processes in step S8 is as follows:

[0030]

[0031] Wherein:

[0032] T(t): The function of the temperature in the furnace changing with time, where t is the time coordinate in seconds;

[0033] P: The heating power, in watts, representing the energy provided by the heating system;

[0034] ρ: The density of the material;

[0035] c p : The specific heat capacity, in J / kg·K, representing the ability of the material to absorb heat;

[0036] V: The volume of the material in the furnace, in m 3 ;

[0037] h: The heat transfer coefficient, in W / m 2 ·K, representing the rate of heat loss in the furnace;

[0038] A: The inner surface area of the furnace, in m 2 ;

[0039] T env : The ambient temperature;

[0040] X(t): The conversion rate of the alloying reaction, representing the degree of completion of the reaction; Where C0 is the initial reactant concentration, in mol / m 3 , C(t): The reactant concentration at time t, in mol / m 3 ;

[0041] k0: The pre-exponential factor, in s -1 , representing the reference value of the reaction rate;

[0042] E a : The activation energy, in J / mol, representing the energy threshold required for the reaction;

[0043] R: The ideal gas constant;

[0044] n: The reaction order, representing the influence degree of the reactant concentration on the reaction rate;

[0045] The rate of change of temperature with time, in K / s;

[0046] The rate of change of the alloying reaction conversion rate with time, in s -1 .

[0047] Preferably, in step S8, the model simulates the process of the temperature in the furnace rising with time by solving a differential equation, sets the initial condition T(0) = T enc , calculates the change of temperature with time T(t) according to the heating power P and the heat transfer coefficient h, and maximizes the conversion rate X(t) of the alloying reaction by adjusting the holding time.

[0048] Preferably, in step S8, according to the Arrhenius equation:

[0049]

[0050] Analyze the influence of temperature on the reaction rate;

[0051] Solve for the conversion rate X(t) by integration:

[0052]

[0053] When the conversion rate X(t) ≥ 0.99, it is determined that the heat preservation is completed.

[0054] Preferably, in step S8:

[0055] The initial temperature in the furnace T(0) = 298K;

[0056] The initial conversion rate X(0) = 0;

[0057] The heating power P = 50kW.

[0058] Preferably, in step S8:

[0059] The material density ρ = 5000kg / m 3 ;

[0060] The volume of the material in the furnace V = 0.1m 3 .

[0061] Preferably, in step S8:

[0062] The inner surface area of the furnace A = 2m 2 ;

[0063] The ambient temperature T env = 298K.

[0064] Preferably, in step S8:

[0065] The pre-exponential factor k0 = 1×10 8 s -1 ;

[0066] The activation energy E a = 150kJ / mol;

[0067] The reaction order n = 1.

[0068] The advantages of this method for producing micro-carbon ferrochrome powder are as follows:

[0069] By optimizing steps such as raw material pretreatment, reduction reaction, metal separation, and alloying reaction, this method solves several key problems existing in the production of micro-carbon ferrochrome powder. First, by precisely mixing raw materials and adding reducing agents, the efficiency and completeness of the reduction reaction are improved, and metal loss is reduced. Second, the design of the new reduction reaction furnace and temperature control ensure the uniformity and stability of the reduction reaction, avoiding incomplete reactions caused by local overheating or overcooling. In addition, by applying calculus and statistical formulas, the reaction conditions and powder particle size distribution are optimized, improving the uniformity and consistency of the product. Finally, moisture-proof packaging and inert gas protection measures effectively prevent the oxidation and moisture absorption of the powder during storage, extending the shelf life of the product. In summary, this method has significant advantages in improving the production efficiency, product quality, and storage stability of micro-carbon ferrochrome powder. Description of the Drawings

[0070] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The same reference numerals are used to represent the same or similar parts in these drawings. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0071] Figure 1 The schematic flow diagram of the method for producing micro-carbon ferrochrome powder according to an embodiment of the present application is schematically shown. Detailed Embodiments

[0072] To make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] In the following description, references to "an embodiment", "embodiments", "an example", "examples", etc. indicate that the embodiments or examples so described may include specific features, structures, characteristics, properties, elements, or limitations, but not every embodiment or example necessarily includes specific features, structures, characteristics, properties, elements, or limitations. Additionally, repeated use of the phrase "according to an embodiment of the present application" does not necessarily refer to the same embodiment, although it may.

[0074] For simplicity, certain technical features known to those skilled in the art are omitted in the following description.

[0075] According to an embodiment of the present application, as Figure 1 shown, the method for producing micro-carbon ferrochrome powder includes the following steps:

[0076] including the following steps:

[0077] S1: Conduct the operation of raw material pretreatment. Select high-purity chromite ore (Cr2O3 content ≥ 45%) and iron ore (Fe2O3 content ≥ 60%), and ensure that the content of impurities (such as SiO2, Al2O3) in the raw materials is less than 2%; use a jaw crusher to crush the ore to a particle size less than 5 mm. During the crushing process, it is necessary to control the feeding speed and crushing pressure to avoid over-crushing; pass the crushed ore through a dry magnetic separator with a magnetic field intensity set at 0.8 - 1.2 T to remove magnetic impurities (such as Fe3O4); send the magnetically separated ore into a ball mill with the ball mill rotation speed controlled at 25 - 30 rpm, the grinding medium being high-chromium steel balls, and the grinding time being 2 hours to ensure that the particle size reaches below 100 mesh; send the finely ground ore slurry into a flotation machine, add a collector (such as sodium oleate) and a foaming agent (such as pine oil), and control the pH value at 8 - 9 to remove non-metallic impurities (such as SiO2);

[0078] This step of crushing and fine grinding increases the surface area of the ore and improves the contact efficiency of subsequent reactions. Magnetic separation and flotation remove impurities through physical and chemical methods to ensure the purity of the raw materials.

[0079] S2: Conduct the operation of raw material mixing. Calculate the mass ratio of chromite ore and iron ore according to the target product composition (such as Cr:Fe = 7:3); use a double-shaft stirring mixer with the stirring speed controlled at 20 - 25 rpm and the mixing time being 30 minutes; randomly sample from the mixed materials and use an X-ray fluorescence spectrometer (XRF) to detect the contents of Cr and Fe to ensure uniform mixing;

[0080] This step of uniform mixing ensures that Cr and Fe can come into full contact during the reduction reaction and avoids incomplete reduction caused by uneven local composition.

[0081] S3: Conduct the steps of reducing agent selection and addition. Select coke with a fixed carbon content ≥ 85%, an ash content ≤ 10%, and a volatile content ≤ 5%; crush the coke to a particle size less than 3 mm and use a vibrating screen for screening to ensure uniform particle size distribution; add coke at 15% of the weight of the mixed ore, and use an automatic weighing system to accurately control the addition amount; put the coke and the mixed ore into the double-shaft stirring mixer again with a stirring speed of 20 rpm and a mixing time of 15 minutes;

[0082] Coke reacts with the oxides in the ore at high temperature to generate metallic chromium and iron, while releasing carbon dioxide;

[0083] S4: Steps for the design of the reduction reactor. The reduction reactor is designed as a three-stage reduction furnace with a high-aluminum refractory lining for the furnace chamber and a thermal insulation layer provided outside the furnace body; the temperature of the preheating zone is 800 °C, the temperature of the reduction zone is 1450 °C, and the cooling zone adopts a water-cooling system with the cooling rate controlled at 50 °C / min; silicon molybdenum rod heating elements are used with a power density of 10 kW / m 2 , and the temperature control accuracy is ±5 °C; nitrogen is introduced into the reduction zone with the flow rate controlled at 10 L / min to prevent metal oxidation;

[0084] The zoned temperature control ensures that the ore is fully preheated in the preheating zone, reaches the optimal reduction temperature in the reduction zone, and is rapidly cooled in the cooling zone to prevent metal oxidation.

[0085] S5: Conduct the reduction reaction. Load the mixed raw materials and reducing agent into the reduction furnace with the loading density controlled at 1.5 - 2.0 g / cm 3 ; Start the heating system with the heating rate of the preheating zone at 10 °C / min and the heating rate of the reduction zone at 15 °C / min; use a thermocouple to monitor the temperature inside the furnace in real time and use a gas analyzer to detect the concentrations of carbon monoxide and carbon dioxide; when the concentration of carbon monoxide drops below 0.1%, it is determined that the reaction is complete;

[0086] In the above reaction, the reaction time and temperature satisfy the following dynamic model:

[0087]

[0088] Where:

[0089] T(x,t): Temperature distribution function at position x and time t inside the furnace, where x is the spatial coordinate inside the furnace and t is the time coordinate;

[0090] α: Thermal diffusivity, unit: m 2 / s, representing the diffusion ability of heat inside the furnace, k is the thermal conductivity, unit: W / m·K; ρ is the material density, unit: kg / m 3 ; c p is the specific heat capacity, unit: J / kg·K;

[0091] Q: Reaction heat, unit: J / mol, representing the heat released by the reduction reaction;

[0092] r(C,T): Reaction rate function, unit: mol / m 3 ·s, representing the influence of reactant concentration and temperature on the reaction rate, C: Reactant concentration, unit: mol / m 3 ; n: Reaction order, representing the degree of influence of reactant concentration on the reaction rate;

[0093] k0: Pre-exponential factor, unit: mol 1-n / m 3(1-n) ·S represents the reference value of the reaction rate;

[0094] E a : Activation energy, unit: J / mol, representing the energy threshold required for the reaction;

[0095] R: Ideal gas constant;

[0096] The rate of change of temperature with time, unit: K / s;

[0097] The second-order partial derivative of temperature in space, unit: K / m 2 , representing the change of temperature gradient;

[0098] At high temperatures, coke undergoes a reduction reaction with chromium oxide and iron oxide in the ore to produce metallic chromium and iron.

[0099] S6: The step of performing metal separation. Pour the reduced material into a centrifuge, and control the rotation speed at 1000 - 1200 rpm; utilize the density difference between metallic chromium and iron (chromium: 7.2 g / cm 3 , iron: 7.87 g / cm 3 ), with a separation time of 10 minutes; collect metallic iron deposited at the bottom and metallic chromium at the upper part respectively;

[0100] Under the action of centrifugal force, the denser metallic iron deposits at the bottom, and the less dense metallic chromium is located at the upper part

[0101] S7: The process of performing metal powder preparation. Put the separated metallic chromium and iron into a ball mill respectively, with the rotation speed of the ball mill at 30 rpm and the grinding time of 4 hours; introduce nitrogen during the ball milling process, with a flow rate of 5 L / min, to prevent the oxidation of metal powder; use a laser particle size analyzer to detect the particle size of the powder to ensure that the particle size reaches below 10 microns;

[0102] The fine grinding process breaks the metal particles to the micron level, increasing their surface area, which is beneficial to the subsequent alloying reaction.

[0103] S8: The step of performing alloying reaction. Mix the metallic chromium powder and iron powder in proportion, use a V-type mixer, with a mixing time of 20 minutes; put the mixed powder into a vacuum induction furnace, heat it to 1600 °C, with a heating rate of 20 °C / min; keep it at 1600 °C for insulation to fully alloy chromium and iron, then turn off the heating system and let the furnace cool naturally to room temperature;

[0104] In the above process, the dynamic models of the heating-up and heat-insulation processes are as follows:

[0105]

[0106] Wherein:

[0107] T(t): The function of the temperature in the furnace changing with time, where t is the time coordinate with the unit of s;

[0108] P: The heating power, with the unit of W, representing the energy provided by the heating system;

[0109] ρ: The material density;

[0110] c p : The specific heat capacity, with the unit of J / kg·K, representing the ability of the material to absorb heat;

[0111] V: The volume of the material in the furnace, with the unit of m 3 ;

[0112] h: The heat transfer coefficient, with the unit of W / m 2 ·K, representing the rate of heat loss in the furnace;

[0113] A: The surface area in the furnace, with the unit of m 2 ;

[0114] T env : The ambient temperature;

[0115] X(t): The conversion rate of the alloying reaction, representing the degree of reaction completion; Where C0 is the initial reactant concentration, with the unit of mol / m 3 , C(t): The reactant concentration at time t, with the unit of mol / m 3 ;

[0116] k0: The pre-exponential factor, with the unit of s -1 , representing the reference value of the reaction rate;

[0117] E a : The activation energy, with the unit of J / mol, representing the energy threshold required for the reaction;

[0118] R: The ideal gas constant;

[0119] n: The reaction order, representing the influence degree of the reactant concentration on the reaction rate;

[0120] The rate of change of temperature with time, with the unit of K / s;

[0121] The rate of change of the conversion rate of the alloying reaction with time, with the unit of S -1 ;

[0122] This model simulates the process of the temperature in the furnace rising with time by solving the differential equation;

[0123] Set the initial condition T(0) = Tenv , calculate the change of temperature with time T(t) according to the heating power P and the heat conduction coefficient h, and maximize the conversion rate of the alloying reaction X(t) by adjusting the heat preservation time;

[0124] According to the Arrhenius equation:

[0125]

[0126] Analyze the influence of temperature on the reaction rate;

[0127] Solve for the conversion rate X(t) by integration:

[0128]

[0129] When the conversion rate X(t) reaches the following condition: X(t) ≥ 0.99, it is determined that the heat preservation is completed;

[0130] The specific operation steps are as follows:

[0131] Initial condition setting:

[0132] The initial temperature in the furnace T(0) = 298K;

[0133] The initial conversion rate X(0) = 0;

[0134] Parameter input:

[0135] The heating power P = 50kW;

[0136] The material density ρ = 5000kg / m 3 ;

[0137] The volume of the material in the furnace V = 0.1m 3 ;

[0138] The inner surface area of the furnace A = 2m 2 ;

[0139] The ambient temperature T env = 298K;

[0140] The pre-exponential factor k0 = 1×10 8 s -1 ;

[0141] The activation energy E a = 150kJ / mol;

[0142] The reaction order n = 1;

[0143] This step solves the following problems:

[0144] The uneven heating rate: Optimize the heating rate through a dynamic temperature model to avoid local overheating or overcooling;

[0145] The holding time is not clear: By using the conversion rate curve, accurately determine the end point of heat preservation to avoid overreaction or underreaction;

[0146] Low reaction efficiency: By adjusting the heating power and holding time, maximize the conversion rate of the alloying reaction and improve production efficiency.

[0147] S9: Perform the steps of powder screening and classification. Pass the alloyed ferrochrome powder through vibrating sieves with mesh apertures of 50 μm, 20 μm, and 10 μm respectively to divide the powder into coarse powder (>50 μm), medium powder (20 - 50 μm), and fine powder (<20 μm); Use a laser particle size analyzer to detect the particle size distribution of each grade of powder.

[0148] S10: Perform the steps of powder packaging and storage. Put the screened ferrochrome powder into an aluminum foil bag, fill it with argon and then seal it, and store the packaged powder in a dry and cool warehouse with the relative humidity controlled below 30%.

[0149] The above-described embodiments merely represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the claims.

Claims

1. A method for producing low-carbon ferrochrome powder, characterized in that: The steps include: S1: Perform raw material pretreatment operations, select high-purity chromium ore and iron ore; use a jaw crusher to crush the ore to a particle size of less than 5mm. During the crushing process, the feed speed and crushing pressure must be controlled to avoid over-crushing; the crushed ore is passed through a dry magnetic separator with a magnetic field strength set to 0.8-1.2T to remove magnetic impurities; the magnetically separated ore is sent to a ball mill with a speed controlled at 25-30rpm. The grinding medium is a high-chromium steel ball. The grinding time is 2 hours to ensure that the particle size is less than 100 mesh; the finely ground ore slurry is sent to a flotation machine, and a collector and a frother are added. The pH value is controlled at 8-9 to remove non-metallic impurities; S2: Perform the operation of mixing raw materials, calculate the mass ratio of chromium ore and iron ore according to the target product composition; use a double-shaft stirring mixer, control the stirring speed at 20-25rpm, and mix for 30 minutes; randomly sample the mixed materials, and use an X-ray fluorescence spectrometer to detect the content of Cr and Fe to ensure uniform mixing; S3: performing a reducing agent selection and addition step, selecting coke with a fixed carbon content of ≥85%, an ash content of ≤10%, and a volatile matter content of ≤5%; crushing the coke to a particle size of less than 3 mm, and screening with a vibrating screen to ensure uniform particle size distribution; adding coke at 15% of the weight of the mixed ore; and placing the coke and the mixed ore into a double-shaft stirring mixer again, stirring at a speed of 20 rpm, and mixing for 15 minutes; S4: Steps of designing the reduction reactor. The reduction reactor is designed as a three-stage reduction furnace. The furnace lining is made of high-aluminum refractory material, and an insulation layer is set on the outside of the furnace body. The temperature of the preheating zone is 800℃, the temperature of the reduction zone is 1450℃, and the cooling zone adopts a water cooling system. The cooling rate is controlled at 50℃ / min. Silicon molybdenum rod heating elements are used, and the power density is 10kW / m 2 , temperature control accuracy ±5℃; nitrogen is introduced into the reduction zone with a flow rate controlled at 10L / min to prevent metal oxidation; S5: Perform reduction reaction, load the mixed raw materials and reducing agent into the reduction furnace, and control the charge density at 1.5-2.0g / cm 3 ; Start the heating system, the heating rate of the preheating zone is 10℃ / min, and the heating rate of the reduction zone is 15℃ / min; use a thermocouple to monitor the temperature in the furnace in real time, and use a gas analyzer to detect the concentration of carbon monoxide and carbon dioxide; when the carbon monoxide concentration drops below 0.1%, the reaction is considered complete; In the above reaction, the reaction time and temperature satisfy the following dynamic model: in: T(x,t): temperature distribution function at position x and time t in the furnace, where x is the spatial coordinate in the furnace and t is the time coordinate; α: thermal diffusion coefficient, unit: m 2 / s, represents the heat diffusion capacity in the furnace, k is thermal conductivity, unit: W / m·K; ρ is material density, unit: kg / m 3 ;c p is the specific heat capacity. Unit: J / kg·K; Q: Reaction heat, unit: J / mol, represents the heat released by the reduction reaction; r(C,T): reaction rate function, unit: mol / m 3 ·s, represents the effect of reactant concentration and temperature on the reaction rate, C: reactant concentration, unit: mol / m 3 ; n: reaction order, which indicates the influence of reactant concentration on reaction rate; k0: pre-exponential factor, unit: mol 1-n / m 3(1-n) S, represents the baseline value of the reaction rate; E a : Activation energy, unit: J / mol, represents the energy threshold required for the reaction; R: ideal gas constant; The rate of change of temperature over time, unit: K / s; The second-order partial derivative of temperature in space, unit: K / m 2 , represents the change of temperature gradient; S6: performing a metal separation step, pouring the reduced material into a centrifugal separator, controlling the rotation speed at 1000-1200 rpm; utilizing the density difference between metal chromium and iron, the separation time is 10 minutes; and collecting the metal iron deposited at the bottom and the metal chromium at the top respectively; S7: The process of preparing metal powder is to put the separated metal chromium and iron into a ball mill respectively, the speed of the ball mill is 30 rpm, and the grinding time is 4 hours; nitrogen is introduced during the ball milling process, with a flow rate of 5 L / min to prevent the metal powder from oxidizing; a laser particle size analyzer is used to detect the powder particle size to ensure that the particle size is less than 10 microns; S8: performing an alloying reaction step, mixing metal chromium powder and iron powder in proportion, using a V-type mixer, and mixing for 20 minutes; placing the mixed powder into a vacuum induction furnace, heating it to 1600° C., with a heating rate of 20° C. / min; maintaining the temperature at 1600° C. to fully alloy the chromium and iron, turning off the heating system, and allowing the furnace to cool naturally to room temperature; S9: performing a powder screening and grading step, wherein the alloyed ferrochrome powder is passed through a vibrating screen with mesh sizes of 50 μm, 20 μm, and 10 μm, respectively, to classify the powder into coarse powder, medium powder, and fine powder; and a laser particle size analyzer is used to detect the particle size distribution of each level of powder; S10: performing the step of powder packaging and storage, packing the sieved ferrochrome powder into an aluminum foil bag, filling it with argon gas and sealing it, and storing the packaged powder in a dry and cool warehouse with a relative humidity controlled below 30%.

2. The method for producing low-carbon ferrochrome powder according to claim 1, characterized in that: Step S1: The Cr2O3 content in the chromium ore is ≥45%, and the Fe2O3 content in the iron ore is ≥60%.

3. The method for producing low-carbon ferrochrome powder according to claim 1, characterized in that: The collector in step S1 is sodium oleate and the foaming agent is pine oil.

4. The method for producing low-carbon ferrochrome powder according to claim 1, characterized in that: The dynamic model of the heating and heat preservation process in step S8 is as follows: in: T(t): The function of the change of furnace temperature over time, t is the time coordinate unit is s; P: Heating power, in W, represents the energy provided by the heating system; ρ: material density; c p : Specific heat capacity, in J / kg·K, indicates the ability of a material to absorb heat; V: Volume of materials in the furnace, in m 3 ; h: thermal conductivity, unit is W / m 2 K, which indicates the rate of heat loss in the furnace; A: furnace surface area, unit: m 2 ; T env : Ambient temperature; X(t): alloying reaction conversion rate, indicating the degree of completion of the reaction; Where C0 is the initial reactant concentration in mol / m 3 , C(t): reactant concentration at time t, in mol / m 3 ; k0: pre-exponential factor, unit is s -1 , represents the baseline value of the reaction rate; E a : Activation energy, in J / mol, represents the energy threshold required for the reaction; R: ideal gas constant; n: Reaction order, which indicates the influence of reactant concentration on reaction rate; The rate of change of temperature with time, in K / s; The rate of change of alloying reaction conversion rate with time, unit is s -1 .

5. The method for producing low carbon ferrochrome powder according to claim 4, characterized in that: In step S8, the model simulates the temperature increase process in the furnace over time by solving the differential equation and sets the initial condition T(0) = T env , according to the heating power P and the heat conductivity h, the temperature change with time T(t) is calculated, and the alloying reaction conversion rate X(t) is maximized by adjusting the holding time.

6. The method for producing low carbon ferrochrome powder according to claim 5, characterized in that: In step S8, according to the Arrhenius equation: Analyze the effect of temperature on reaction rate; Solve the conversion rate X(t) by integration: When the conversion rate X(t)≥0.99, the insulation is determined to be completed.

7. The method for producing micro-carbon ferrochrome powder according to claim 6, characterized in that: In step S8: The initial temperature in the furnace is T(0) = 298K; Initial conversion rate X(0) = 0; Heating power P = 50kW.

8. The method for producing low carbon ferrochrome powder according to claim 6, characterized in that: In step S8: Material density ρ=5000kg / m 3 ; The volume of the material in the furnace V = 0.1m 3 .

9. The method for producing micro-carbon ferrochrome powder according to claim 6, characterized in that: In step S8: Furnace surface area A = 2m 2 ; Ambient temperature T env =298K.

10. The method for producing low carbon ferrochrome powder according to claim 6, characterized in that: In step S8: Pre-exponential factor k0 = 1 × 10 8 s -1 ; Activation Energy E a =150 kJ / mol; Reaction order n=1.

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