Smelting method of ferrotitanium alloy

Abstract

The invention discloses a smelting method of a titanium-iron alloy, which comprises the following steps: taking low-grade titanium minerals such as titanium concentrate and titanium slag as titanium ore raw materials, taking carbon and aluminum as reducing agents, and realizing semi-continuous preparation of the titanium-iron alloy in a carbothermic and aluminothermic two-stage reduction mode. According to the method disclosed by the invention, selective directional reduction of an iron element is carried out by adopting a'low-first and high-second 'proportioning mode in a carbon thermal reduction process, so that a high-quality intermediate titanium raw material and low-carbon molten iron are obtained; in the aluminothermic reduction process, a'metal slag blending 'batching mode is adopted for titanium slag-metal bidirectional strengthening reduction, titanium oxidation and uniform mixing of titanium and iron melts are achieved, and finally a titanium-iron alloy product with chemical components meeting the labeling requirements is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy smelting, in particular to a smelting method of titanium-ferroalloy. Background Art

[0002] As a major steel producer, my country's smelting technology has reached the world's advanced level. Ferro-titanium alloy is suitable for use as a deoxidation refining agent and grain refiner for special steel smelting due to its low melting point, suitable specific gravity, and low impurity content. It plays an irreplaceable role in improving the quality of high-grade alloy steels for military and aviation purposes, and is a quality-oriented high-quality intermediate alloy.

[0003] The smelting of titanium-ferroalloy mainly uses titanium-containing ore as raw material, metal aluminum, silicon or carbon as reducing agent, and mixed reduction according to a certain ratio, and finally obtains titanium-ferroalloy products that meet the standard requirements. Since the reduction ability of silicon and carbon is relatively weak, the reduction effect on titanium is poor, resulting in great difficulty in smelting, low smelting yield, and no qualified titanium-ferroalloy products. Therefore, metal aluminum is the preferred reducing agent for smelting titanium-ferroalloy. The industrial production process of aluminothermic reduction smelting titanium-ferroalloy is generally as follows: mixing titanium-containing ore with metal aluminum, and conducting aluminothermic self-propagating reaction in the reaction carrier, and cooling after the slag and gold are completely separated. During the reduction process, substances such as CaO are added as slag-forming agents to reduce the melting point of the slag and promote the separation of the alloy from the slag. However, since the aluminothermic reduction process belongs to a strong reduction system, it has strong reduction characteristics for weakly reducing metals / non-metals in the raw materials. Therefore, the composition requirements for titanium raw materials in the aluminothermic reduction process for preparing titanium-ferroalloy are very stringent, and high-purity TiO2 is generally used as the main titanium source.

[0004] Therefore, in view of the stringent requirements of existing technologies that require high-purity TiO2 as the main titanium source, it is urgent to develop a smelting method that can smelt low-grade titanium minerals to obtain high-quality ferrotitanium alloy products, and can effectively avoid the influence of the complex components of low-grade titanium minerals on the quality of the generated alloy products. By utilizing the iron element in low-grade titanium minerals, qualified ferrotitanium alloy products can be directly prepared in a short process. The heat of the intermediate products can also be fully utilized to significantly save the use of high-priced reducing agents and unit smelting electricity consumption, which has very important economic value. Summary of the invention

[0005] The object of the present invention is to provide a smelting method of titanium-iron alloy, which uses low-grade titanium minerals such as titanium concentrate and titanium slag as titanium raw materials, uses carbon and aluminum as reducing agents, and realizes semi-continuous preparation of titanium-iron alloy through a two-stage reduction method of carbon thermal and aluminum thermal; wherein, the carbon thermal reduction process adopts a "low first and then high" batching mode to carry out selective directional reduction of iron elements, so as to obtain high-quality intermediate titanium raw materials and low-carbon molten iron; the aluminum thermal reduction process adopts a "gold-slag blending" batching mode to carry out two-way enhanced reduction of titanium elements, slag and gold, so as to realize the oxidation of titanium and the uniform mixing of titanium and iron melts, and finally obtain a titanium-iron alloy product whose chemical composition meets the labeling requirements.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a smelting method of titanium-iron alloy, preferably comprising the following steps: Step (1): mixing a first portion of titanium ore raw material with a first portion of reducing agent carbon powder to prepare a first batch of mixed materials, wherein the weight of the first portion of reducing agent carbon powder is X times the theoretical carbon content, and X is less than 1.0; Step (2): mixing a second portion of titanium ore raw material with a second portion of reducing agent carbon powder to prepare a second batch of mixed material, wherein the weight of the second reducing agent carbon powder is Y times the theoretical carbon content, and Y>1.0; Step (3): adding the first batch of mixed materials to the first electric furnace for smelting to obtain reduced iron water, tapping the first electric furnace and transferring the reduced iron water to the second electric furnace, adding the first portion of reducing agent aluminum particles and iron material to adjust the composition; Step (4): after the first electric furnace of step (3) taps iron, a second batch of mixed materials is added for smelting, and when the expected end point of the carbon thermal reduction reaction is reached, slag is tapped, and the tapped molten titanium slag and the second portion of reducing agent aluminum particles are added to the second electric furnace of step (3) and stirred to carry out aluminothermic reaction; Step (5): After the aluminum heat reaction in the second electric furnace is completed, the power supply is turned off, and the second electric furnace is transferred to a cooling zone for natural cooling and then subjected to a subsequent processing flow to obtain a titanium-iron alloy.

[0007] In the present invention, the theoretical carbon content is the sum of the weight of the reducing agent carbon powder required for the complete reduction of the iron oxide in the corresponding titanium ore raw material and the weight of the reducing agent carbon powder considering the additional burning loss during the smelting process. The first portion of reducing agent carbon powder is X times the theoretical carbon content of the first portion of titanium ore raw material, and X is less than 1.0, and the second portion of reducing agent carbon powder is Y times the theoretical carbon content of the second portion of titanium ore raw material, and Y is greater than 1.0. According to the smelting method of titanium-iron alloy described in the present invention, preferably, in the step (1), the TiO2 content in the titanium ore raw material is ≥45.0wt%.

[0008] According to the titanium-iron alloy smelting method of the present invention, preferably, in the step (1), the total amount of metal / non-metal oxides including iron, manganese and silicon in the titanium ore raw material is ≤55wt%.

[0009] According to the titanium-iron alloy smelting method of the present invention, preferably, in the step (1), the manganese oxide content in the titanium ore raw material is ≤1.0wt.%, and the silicon oxide content is ≤5.0wt.%.

[0010] According to the titanium-iron alloy smelting method described in the present invention, preferably, in the steps (1) and (2), the reducing agent carbon powder is one or more of artificial graphite, natural graphite or semi-coke, and the effective component thereof is ≥ 98.0wt%.

[0011] According to the titanium-iron alloy smelting method of the present invention, preferably, in the step (1) and the step (2), the weight ratio of the first titanium ore raw material to the second titanium ore raw material is 3-7:7-3.

[0012] According to the titanium-iron alloy smelting method of the present invention, preferably, in the step (3) and the step (4), the weight ratio of the first portion of reducing agent aluminum particles to the second portion of reducing agent aluminum particles is 1-3:10-7.

[0013] According to the titanium-iron alloy smelting method of the present invention, preferably, in the step (2), the judgment criterion for the end of the electrothermal reaction is that the rate of decrease of the total titanium content in the smelting slag is ≤0.01wt% / min.

[0014] According to the titanium-iron alloy smelting method described in the present invention, preferably, in the step (1) and the step (2), the sum of the mass of the first portion of reducing agent carbon powder and the mass of the second portion of reducing agent carbon powder is 1.00 to 1.10 times the theoretical carbon content of the two portions of titanium ore raw materials.

[0015] In the present invention, the sum of the mass of the first reducing agent carbon powder and the mass of the second reducing agent carbon powder is 1.00-1.10 times the theoretical carbon content of the two titanium ore raw materials (ie, the carbon content coefficient is 1.00-1.10).

[0016] According to the titanium-iron alloy smelting method described in the present invention, preferably, in step (3) and step (4), the sum of the masses of the first portion of reducing agent aluminum particles and the second portion of reducing agent aluminum particles is 1.00 to 1.10 times the theoretical aluminum content of the two batches of mixed materials.

[0017] The theoretical aluminum content is the sum of the mass of the reducing agent aluminum particles required to completely reduce the titanium oxide in the molten titanium slag and the mass of the aluminum content required to produce the upper limit of the aluminum content of the alloy component of this grade. The mass of the first batch of reducing agent aluminum particles is the aluminum content of titanium oxide in the molten titanium slag corresponding to the first batch of mixed materials, and the mass of the second batch of reducing agent aluminum particles is the aluminum content of titanium oxide in the molten titanium slag corresponding to the second batch of mixed materials. The sum of the masses of the first batch of reducing agent aluminum particles and the second batch of reducing agent aluminum particles is 1.00~1.10 times the theoretical aluminum content of the two batches of mixed materials (that is, the aluminum content coefficient is 1.00~1.10).

[0018] In the present invention, the second electric furnace is preferably a disposable detachable furnace body.

[0019] As a more preferred technical solution of the present invention, in the step (3), the amount of iron material added is calculated based on the theoretical total amount of titanium and impurity elements in the target grade of ferro-titanium alloy and the weight of the reduced molten iron in the step (3).

[0020] The calculation method of iron material addition is as follows: The amount of iron material added = (amount of titanium slag added × titanium slag grade × titanium smelting yield) × (theoretical titanium content median of target grade titanium-iron alloy - upper limit of theoretical impurity content of target grade) / (1-theoretical titanium content median of target grade titanium-iron alloy) - amount of molten iron added.

[0021] The beneficial effects of the present invention are: The present invention provides a smelting method of titanium-ferroalloy, which uses low-grade titanium minerals such as titanium concentrate and titanium slag as titanium raw materials, uses carbon and aluminum as reducing agents, and realizes semi-continuous preparation of titanium-ferroalloy by a two-stage carbon thermal and aluminum thermal reduction method; wherein, the carbon thermal reduction process adopts a "low first then high" batching mode to carry out selective directional reduction of iron elements, so as to obtain high-quality intermediate titanium raw materials and low-carbon molten iron; the aluminum thermal reduction process adopts a "gold-slag blending" batching mode to carry out two-way enhanced reduction of titanium elements, slag and gold, so as to realize oxidation of titanium and uniform mixing of titanium and iron melts, and finally obtain a titanium-ferroalloy product whose chemical composition meets the labeling requirements.

[0022] Compared with the traditional smelting process, the smelting method of the present invention not only ensures the quality of titanium-ferroalloy products, but also expands the application scope of titanium raw materials, shortens the preparation process of titanium-ferroalloy, and greatly reduces the processing and manufacturing cost of titanium-ferroalloy. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments.

[0024] The specific composition content of the titanium ore raw material used in the embodiment of the present invention is shown in Table 1: Table 1 Element <![CDATA[TiO2]]> FeO <![CDATA[Fe2O3]]> MgO MnO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[V2O5]]> Content / wt% 49.5 39.7 3.7 4.2 0.9 1.5 0.4 ＜0.1 Example 1 Taking the preparation of FeTi70 as an example, a smelting method of a titanium-iron alloy in this embodiment includes the following steps: Step (1): 7 parts by weight of the first titanium ore raw material and the first reducing agent carbon powder are mixed to prepare a first batch of mixed materials, wherein the weight of the first reducing agent carbon powder is 0.9 times the theoretical carbon content of the first titanium ore raw material; Step (2): Mixing 3 parts by weight of the second titanium ore raw material with the second reducing agent carbon powder to prepare a second batch of mixed material, wherein the mass of the second reducing agent carbon powder is 2.3 times the theoretical carbon content of the second titanium ore raw material; Step (3): adding the first batch of mixed materials to the first electric furnace for smelting to obtain reduced iron water, tapping the first electric furnace and transferring the reduced iron water to the second electric furnace, adding the first portion of reducing agent aluminum particles and iron material to adjust the composition; Step (4): after the first electric furnace of step (3) taps iron, a second batch of mixed materials is added for smelting, and when the expected end point of the carbon thermal reduction reaction is reached, slag is tapped, and the tapped molten titanium slag and the second portion of reducing agent aluminum particles are added to the second electric furnace of step (3) and stirred to carry out aluminothermic reaction; Step (5): After the aluminum heat reaction in the second electric furnace is completed, the power supply is turned off, and the second electric furnace is transferred to a cooling zone for natural cooling and then subjected to a subsequent processing flow to obtain a titanium-iron alloy.

[0025] In step (1) and step (2), the comprehensive carbon ratio of the first titanium ore raw material and the second titanium ore raw material is 1.0; in step (3) and step (4), the comprehensive aluminum ratio of the first batch of mixed materials and the second batch of mixed materials is 1.0, and the weight ratio of the first batch of reducing agent aluminum particles to the second batch of reducing agent aluminum particles is 3:7; the amount of iron material added is calculated based on the theoretical total amount of titanium and impurity elements in the target grade of titanium iron alloy and the weight of the reduced molten iron in step (3). The amount of iron material added = (10 parts by weight of titanium slag × titanium slag grade × titanium smelting yield) × (70%-10%) / (1-70%) - the amount of molten iron added.

[0026] After the above-mentioned batching and smelting, the carbon content of the obtained reduced iron water is 0.4wt%, the titanium smelting yield reaches 82.4%, the unit alloy power consumption is 3320kWh, and the composition of the obtained titanium-iron alloy product meets the FeTi70-C standard requirements.

[0027] Example 2 Taking the preparation of FeTi70 as an example, a smelting method of a titanium-iron alloy in this embodiment includes the following steps: Step (1): Mix 5 parts by weight of the first titanium ore raw material with the first reducing agent carbon powder to prepare a first batch of mixed materials, wherein the weight of the first reducing agent carbon powder is 0.8 times the theoretical carbon content of the first titanium ore raw material; Step (2): Mixing 5 parts by weight of the second titanium ore raw material with the second reducing agent carbon powder to prepare a second batch of mixed material, wherein the mass of the second reducing agent carbon powder is 1.2 times the theoretical carbon content of the second titanium ore raw material; Step (3): adding the first batch of mixed materials to the first electric furnace for smelting to obtain reduced iron water, tapping the first electric furnace and transferring the reduced iron water to the second electric furnace, adding the first portion of reducing agent aluminum particles and iron material to adjust the composition; Step (4): after the first electric furnace of step (3) taps iron, a second batch of mixed materials is added for smelting, and when the expected end point of the carbon thermal reduction reaction is reached, slag is tapped, and the tapped molten titanium slag and the second portion of reducing agent aluminum particles are added to the second electric furnace of step (3) and stirred to carry out aluminothermic reaction; Step (5): After the aluminum heat reaction in the second electric furnace is completed, the power supply is turned off, and the second electric furnace is transferred to a cooling zone for natural cooling and then subjected to a subsequent processing flow to obtain a titanium-iron alloy.

[0028] In step (1) and step (2), the comprehensive carbon ratio of the first titanium ore raw material and the second titanium ore raw material is 1.0; in step (3) and step (4), the comprehensive aluminum ratio of the first batch of mixed materials and the second batch of mixed materials is 1.0, and the weight ratio of the first batch of reducing agent aluminum particles to the second batch of reducing agent aluminum particles is 2:8; the amount of iron material added is calculated based on the theoretical total amount of titanium and impurity elements in the target grade of titanium iron alloy and the weight of the reduced molten iron in step (3). The amount of iron material added = (10 parts by weight of titanium slag × titanium slag grade × titanium smelting yield) × (70%-10%) / (1-70%) - the amount of molten iron added.

[0029] After the above-mentioned batching and smelting, the carbon content of the obtained reduced iron water is 0.3wt%, the titanium smelting yield reaches 83.5%, the unit alloy power consumption is 3240kWh, and the composition of the obtained titanium-iron alloy product meets the FeTi70-B standard requirements.

[0030] Example 3 Taking the preparation of FeTi70 as an example, a smelting method of a titanium-iron alloy in this embodiment includes the following steps: Step (1): 3 parts by weight of the first titanium ore raw material and the first reducing agent carbon powder are mixed to prepare a first batch of mixed materials, wherein the weight of the first reducing agent carbon powder is 0.8 times the theoretical carbon content of the first titanium ore raw material; Step (2): mixing 7 parts by weight of the second titanium ore raw material with the second reducing agent carbon powder to prepare a second batch of mixed material, wherein the mass of the second reducing agent carbon powder is 1.1 times the theoretical carbon content of the second titanium ore raw material; Step (3): adding the first batch of mixed materials to the first electric furnace for smelting to obtain reduced iron water, tapping the first electric furnace and transferring the reduced iron water to the second electric furnace, adding the first portion of reducing agent aluminum particles and iron material to adjust the composition; Step (4): after the first electric furnace of step (3) taps iron, a second batch of mixed materials is added for smelting, and when the expected end point of the carbon thermal reduction reaction is reached, slag is tapped, and the tapped molten titanium slag and the second portion of reducing agent aluminum particles are added to the second electric furnace of step (3) and stirred to carry out aluminothermic reaction; Step (5): After the aluminum heat reaction in the second electric furnace is completed, the power supply is turned off, and the second electric furnace is transferred to a cooling zone for natural cooling and then subjected to a subsequent processing flow to obtain a titanium-iron alloy.

[0031] In step (1) and step (2), the comprehensive carbon ratio of the first titanium ore raw material and the second titanium ore raw material is 1.0; in step (3) and step (4), the comprehensive aluminum ratio of the first batch of mixed materials and the second batch of mixed materials is 1.0, and the weight ratio of the first batch of reducing agent aluminum particles and the second batch of reducing agent aluminum particles is 1:9; the amount of iron material added is calculated based on the theoretical total amount of titanium and impurity elements in the target grade of titanium iron alloy and the weight of the reduced molten iron in step (3). Amount of iron material added = (10 parts by weight of titanium slag × titanium slag grade × titanium smelting yield) × (70%-5%) / (1-70%) - amount of molten iron added After the above-mentioned batching and smelting, the carbon content of the obtained reduced iron water is 0.2wt%, the titanium smelting yield reaches 84.2%, the unit alloy power consumption is 3160kWh, and the composition of the obtained titanium-iron alloy product meets the FeTi70-A standard requirements.

[0032] Example 4 Taking the preparation of FeTi70 as an example, a smelting method of a titanium-iron alloy in this embodiment includes the following steps: Step (1): 3 parts by weight of the first titanium ore raw material and the first reducing agent carbon powder are mixed to prepare a first batch of mixed materials, wherein the weight of the first reducing agent carbon powder is 0.8 times the theoretical carbon content of the first titanium ore raw material; Step (2): Mixing 7 parts by weight of the second titanium ore raw material with the second reducing agent carbon powder to prepare a second batch of mixed material, wherein the mass of the second reducing agent carbon powder is 1.2 times the theoretical carbon content of the second titanium ore raw material; Step (3): adding the first batch of mixed materials to the first electric furnace for smelting to obtain reduced iron water, tapping the first electric furnace and transferring the reduced iron water to the second electric furnace, adding the first portion of reducing agent aluminum particles and iron material to adjust the composition; Step (4): after the first electric furnace of step (3) taps iron, a second batch of mixed materials is added for smelting, and when the expected end point of the carbon thermal reduction reaction is reached, slag is tapped, and the tapped molten titanium slag and the second portion of reducing agent aluminum particles are added to the second electric furnace of step (3) and stirred to carry out aluminothermic reaction; Step (5): After the aluminum heat reaction in the second electric furnace is completed, the power supply is turned off, and the second electric furnace is transferred to a cooling zone for natural cooling and then subjected to a subsequent processing flow to obtain a titanium-iron alloy.

[0033] In step (1) and step (2), the comprehensive carbon ratio of the first titanium ore raw material and the second titanium ore raw material is 1.10; in step (3) and step (4), the comprehensive aluminum ratio of the first batch of mixed materials and the second batch of mixed materials is 1.10, and the weight ratio of the first batch of reducing agent aluminum particles to the second batch of reducing agent aluminum particles is 1:10; the amount of iron material added is calculated based on the theoretical total amount of titanium and impurity elements in the target grade of titanium iron alloy and the weight of the reduced molten iron in step (3). The amount of iron material added = (10 parts by weight of titanium slag × titanium slag grade × titanium smelting yield) × (70%-10%) / (1-70%) - the amount of molten iron added.

[0034] After the above-mentioned batching and smelting, the carbon content of the obtained reduced iron water is 0.2wt%, the titanium smelting yield reaches 84.5%, the unit alloy power consumption is 3110kWh, and the composition of the obtained titanium-iron alloy product meets the FeTi70-B standard requirements.

[0035] Comparative Example: The comparative example uses the same smelting furnace body, titanium ore raw material, reducing agent carbon powder and reducing agent aluminum particles as those in the above-mentioned embodiment, wherein the masses of the reducing agent carbon powder and the reducing agent aluminum particles are proportioned according to the theoretical carbon proportioning amount and the theoretical aluminum proportioning amount, and carbon thermal reduction reaction and aluminothermic reduction reaction are carried out in sequence; wherein, the carbon proportioning process adopts uniform carbon proportioning, that is, the carbon proportioning coefficient is maintained at 1.0 unchanged, and all aluminum particles are added simultaneously with the molten titanium slag in the aluminothermic reduction process, the comprehensive aluminum proportioning coefficient is 1.0, and other operating conditions are exactly the same as those in Examples 1-4, to prepare titanium-iron alloy products.

[0036] After the above-mentioned ingredients and smelting, the carbon content of the obtained molten iron is 1.5%, the titanium smelting yield reaches 79.3%, the unit alloy power consumption is 3500kWh, and the composition of the titanium iron product does not meet the FeTi70 standard requirements.

[0037] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for smelting titanium-iron alloy, characterized in that: The steps include: Step (1): mixing a first portion of titanium ore raw material with a first portion of reducing agent carbon powder to prepare a first batch of mixed materials, wherein the mass of the first portion of reducing agent carbon powder is X times the theoretical carbon content, and X is less than 1.0; Step (2): mixing a second portion of titanium ore raw material with a second portion of reducing agent carbon powder to prepare a second batch of mixed material, wherein the mass of the second reducing agent carbon powder is Y times the theoretical carbon content, and Y>1.0; Step (3): adding the first batch of mixed materials to the first electric furnace for smelting to obtain reduced iron water, tapping the first electric furnace and transferring the reduced iron water to the second electric furnace, adding the first portion of reducing agent aluminum particles and iron material to adjust the composition; Step (4): after the first electric furnace of step (3) taps iron, a second batch of mixed materials is added for smelting, and when the expected end point of the carbon thermal reduction reaction is reached, slag is tapped, and the tapped molten titanium slag and the second portion of reducing agent aluminum particles are added to the second electric furnace of step (3) and stirred to carry out aluminothermic reaction; Step (5): After the aluminum heat reaction in the second electric furnace is completed, the power supply is turned off, and the second electric furnace is transferred to a cooling zone for natural cooling and then subjected to a subsequent processing flow to obtain a titanium-iron alloy.

2. The smelting method of a titanium-iron alloy according to claim 1, characterized in that: In the step (1), the TiO2 content in the titanium ore raw material is ≥45.0wt%.

3. The smelting method of a titanium-iron alloy according to claim 1, characterized in that: In the step (1), the total amount of reducing metal / non-metal oxides in the titanium ore raw material is ≤55wt%, the reducing metal oxides include iron oxides and manganese oxides, and the reducing non-metal oxides include silicon oxides.

4. The smelting method of a titanium-iron alloy according to claim 1, characterized in that: In the step (1), the manganese oxide content in the titanium ore raw material is ≤1.0wt.%, and the silicon oxide content is ≤5.0wt.%.

5. The smelting method of titanium-iron alloy according to claim 1, characterized in that: In the steps (1) and (2), the reducing agent carbon powder is one or more of artificial graphite, natural graphite or blue carbon, and its effective component is ≥ 98.0wt%.

6. The smelting method of titanium-iron alloy according to claim 1, characterized in that: In the step (1) and the step (2), the weight ratio of the first titanium ore raw material to the second titanium ore raw material is 3-7:7-3.

7. The smelting method of titanium-iron alloy according to claim 2, characterized in that: In the step (3) and the step (4), the mass ratio of the first portion of reducing agent aluminum particles to the second portion of reducing agent aluminum particles is 1-3:10-7.

8. The smelting method of titanium-iron alloy according to claim 1, characterized in that: In the step (2), the criterion for determining the end of the electrothermal reaction is that the rate of decrease of the total titanium content in the smelting slag is ≤0.01wt% / min.

9. A smelting method of titanium-iron alloy according to any one of claims 1 to 8, characterized in that: In the step (1) and the step (2), the sum of the mass of the first portion of reducing agent carbon powder and the mass of the second portion of reducing agent carbon powder is 1.00 to 1.10 times the theoretical carbon content of the two portions of titanium ore raw materials.

10. The smelting method of titanium-iron alloy according to claim 1, characterized in that: In the steps (3) and (4), the sum of the masses of the first batch of reducing agent aluminum particles and the second batch of reducing agent aluminum particles is 1.00 to 1.10 times the theoretical aluminum content of the two batches of mixed materials.