Method for preparing low-titanium-iron alloy by utilizing reduced ilmenite

Abstract

The invention discloses a method for preparing a low-titanium-iron alloy by using reduced ilmenite. The method comprises the following steps: S1, drying the reduced ilmenite, titanium concentrate and lime at a certain temperature for later use; and S2, uniformly mixing the reduced ilmenite, the titanium concentrate and the lime obtained in the step S1 with aluminum powder and iron powder according to a certain proportion, paving a combustion improver in a certain proportion on the surface, igniting by adopting an ignition agent, and initiating an aluminothermic reduction reaction. And S3, cooling a reaction product in the step S2 to normal temperature, and sorting the reaction product to obtain the low-titanium iron alloy and slag. And S4, the low-titanium-iron alloy obtained in the step S3 is ground under the condition of a protective agent, and a low-titanium-iron alloy product with a certain mesh number is prepared. According to the method, the low-titanium-iron alloy is prepared through aluminothermic reduction, and the raw material ratio is regulated and controlled to replace a certain proportion of titanium concentrate with reduced ilmenite, so that the use amount of a reducing agent aluminum is reduced, and the purpose of greatly reducing the production cost is achieved. The method is simple in technological process, low in energy consumption, short in period, low in production cost and high in economic benefit.

Description

Technical Field

[0001] The invention belongs to the technical field of comprehensive utilization of titanium resources, and particularly relates to a method for preparing a low-titanium ferroalloy by reducing ilmenite. Background Art

[0002] Ferrotitanium alloy is a special alloy widely used in the field of steel metallurgy. Adding ferrotitanium alloy in the steelmaking process can play a role in grain refinement, deoxidation and desulfurization, corrosion resistance, and improving steel strength. According to the different titanium content in ferrotitanium alloy, ferrotitanium alloy can be divided into three grades: high ferrotitanium (FeTi70) containing 65%-75% Ti, medium ferrotitanium (FeTi40) containing 35%-45% Ti, and low ferrotitanium (FeTi30) containing 25%-35% Ti. Among them, low ferrotitanium alloy plays an important role in the steel industry due to its economy and functionality. It is especially suitable for fields that are sensitive to cost and need to take into account performance.

[0003] Currently, the main methods for producing low-titanium ferrometallurgy are remelting and aluminothermic reduction. The former has high production costs, low yields, and poor overall economic benefits. Domestically, the remelting method, with its largely imported raw materials, further increases costs, severely restricting the development of this technology. The aluminothermic reduction method, which utilizes the heat released by the aluminothermic reaction to maintain the reaction, has lower energy consumption and reduced production costs. Cost control is primarily determined by the amount of aluminum used as the reducing agent.

[0004] Low-titanium ferroalloys are produced using the aluminothermic reduction method. By replacing a certain proportion of ilmenite concentrate with reduced ilmenite, the amount of aluminum used as the reducing agent is reduced, thereby lowering production costs and increasing economic benefits. Therefore, developing a method for producing low-titanium ferroalloys using reduced ilmenite would provide the steel and metallurgical industry with a low-cost, high-quality low-titanium ferroalloy. This would be of great significance for the efficient utilization of titanium resources and the development of specialty alloys. In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to reduce the cost of producing low-titanium ferroalloy by the existing aluminothermic reduction method and increase economic benefits. The method provides a method for preparing low-titanium ferroalloy by reducing ilmenite. The method has high resource utilization, reasonable process design and simple operation.

[0006] The present invention provides the following technical solution: a method for preparing a low-titanium ferroalloy by reducing ilmenite, comprising the following steps:

[0007] S1. The three reaction raw materials, namely, reduced ilmenite, titanium concentrate and lime, are dried at a certain temperature in advance for later use.

[0008] S2. Mix the reaction raw materials of reduced ilmenite, titanium concentrate, lime, aluminum powder and iron powder in a certain proportion, place them in an aluminothermic reactor, spread a certain proportion of combustion aid on the surface of the mixture, ignite it with an ignition agent, and initiate the aluminothermic reduction reaction.

[0009] S3. Cooling the product obtained from the thermite reaction in step S2 to room temperature, and sorting it to obtain a low-titanium ferroalloy and slag.

[0010] S4. Grinding the low-titanium ferroalloy obtained in step S3 under protective agent conditions to obtain a low-titanium ferroalloy product with a certain mesh size.

[0011] Preferably, in step S1, the TiO2 content in the reduced ilmenite is 54-60%, and the TiO2 content in the titanium concentrate is 51-57%.

[0012] Preferably, in step S1, the reduced ilmenite and ilmenite concentrate are dried at a temperature of 120-150° C. for 8-12 hours, the lime is dried at a temperature of 80-100° C. for 8-12 hours, the particle size of the reduced ilmenite and ilmenite concentrate is 80-120 mesh, and the particle size of the lime is 200-400 mesh.

[0013] Preferably, in step S2, the particle size of the aluminum powder is 80-100 mesh, the particle size of the iron powder is 80-100 mesh, the mixing time of the reaction raw materials should be ≤5 min, the combustion aid is sodium chlorate or potassium chlorate or a mixture of the two, and the ignition agent is magnesium strips or calcium powder.

[0014] Preferably, in step S3, the thermal reaction product is sorted manually, and the low-titanium ferroalloy and slag are selected after crushing.

[0015] Preferably, in step S4, the protective agent used is a water-based solution, whose main components are deionized water (accounting for 85-95%), a lubricant (polyethylene glycol, 3-5%), a rust remover (triethanolamine, accounting for 3-5%), an antioxidant (benzotriazole, accounting for 0.1-0.4%, a borate, accounting for 1-2%), a pH adjuster (sodium hydroxide, accounting for 0-1%), and the grinding time is 1-2 hours.

[0016] The beneficial effects of the present invention are:

[0017] The present invention provides a method for preparing a low-titanium ferroalloy using reduced ilmenite. By performing heat balance and material balance on the reaction raw materials and changing the ratio of reduced ilmenite, titanium concentrate and aluminum powder, a target low-titanium ferroalloy is obtained. On the one hand, the method uses aluminothermic reduction to prepare the low-titanium ferroalloy, which has a simple process flow, low energy consumption and a short cycle. On the other hand, the method uses reduced ilmenite to replace a certain proportion of titanium concentrate to reduce the amount of reducing agent aluminum to obtain the target low-titanium ferroalloy. All of these have been verified through small-scale tests, pilot tests and scaled-up production, and can indeed achieve the purpose of significantly reducing production costs and increasing economic benefits. In summary, the method has a simple process flow, low energy consumption, a short cycle, low production costs and high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A process flow chart of an embodiment of the present invention (summary attached);

[0019] Figure 2 This is a physical picture of the titanium-iron alloy prepared in Example 1 of the present invention;

[0020] Figure 3 This is a scanning electron microscope image of the titanium-iron alloy prepared in Example 1 of the present invention;

[0021] Figure 4 This is a physical picture of the titanium-iron alloy prepared in Example 2 of the present invention;

[0022] Figure 5 This is a scanning electron microscope image of the titanium-iron alloy prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to the accompanying drawings and examples, but the specific implementation of the present invention is not limited to the following examples.

[0024] Example 1

[0025] The raw materials are titanium concentrate with a TiO2 mass content of 56.82%, reduced ilmenite with a TiO2 mass content of 59.45%, aluminum powder, lime, and iron powder, potassium chlorate as a combustion aid, and magnesium strips as an ignition agent.

[0026] The reduced ilmenite, ilmenite concentrate, and lime were dried at 120°C, 120°C, and 80°C, respectively, for 12 hours before use. The raw material ratio (ilmenite concentrate: reduced ilmenite: aluminum powder: potassium chlorate: lime: iron powder = 70%: 30%: 41%: 15%: 15%: 32.7%) was determined by heat balance and mass calculation of the reaction raw materials. The ilmenite, ilmenite concentrate, lime, aluminum powder, and iron powder were mixed for 3 minutes. The mixed raw materials were then added to an aluminothermic reactor, the surface of which was evenly covered with potassium chlorate. A magnesium rod was inserted and ignited with an open flame to initiate a thermite reaction. After the reaction was complete (generally 1 to 3 minutes), the reaction product was cooled to room temperature and removed for use.

[0027] The reaction product is crushed, and the alloy and slag are preliminarily sorted out. The preliminarily selected alloy is added to the grinding tank, and sufficient deionized water is added as a protective agent. The alloy product (alloy particle size 1-5mm) is obtained by grinding and screening. The actual alloy product is as follows: Figure 2 The scanning electron microscope images of the alloy are shown in Figure 3 .

[0028] After testing, the mass percentage of Ti in the alloy product obtained in Example 1 is 25.13%, and the mass percentages of C, Si, P, S, Al, Mn, and Cu are 0.03%, 3.2%, 0.01%, 0.01%, 1.78%, 1.3%, and 0.07%, respectively, which meet the requirements of low titanium iron FeTi30-A in GB / T3282-2012.

[0029] After calculation, in Example 1, by replacing the titanium concentrate with 30% of reduced ilmenite, the amount of aluminum powder used can be reduced by 25.5% compared with the actual production, and the comprehensive production cost of low-titanium ferro can be reduced by 15.3% per ton.

[0030] Example 2

[0031] The raw materials are titanium concentrate with a TiO2 mass content of 56.82%, reduced ilmenite with a TiO2 mass content of 59.45%, aluminum powder, lime, and iron powder, potassium chlorate as a combustion aid, and magnesium strips as an ignition agent.

[0032] The specific process steps refer to Example 1. Considering that the mass percentage of Ti in the low-titanium ferroalloy produced in Example 1 is relatively low, the addition amount of aluminum powder in the raw material ratio is changed to 43%. The other conditions are the same as Example 1. The actual alloy product is as follows Figure 4 The scanning electron microscope images of the alloy are shown in Figure 5 .

[0033] After testing, the mass percentage of Ti in the alloy product obtained in Example 2 is 28.76%, and the mass percentages of C, Si, P, S, Al, Mn, and Cu are 0.02%, 3.67%, 0.0058%, 0.008%, 1.73%, 1.06%, and 0.03%, respectively, which meet the requirements of low titanium iron FeTi30-A in GB / T3282-2012.

[0034] After calculation, in Example 2, by replacing the titanium concentrate with 30% of reduced ilmenite, the amount of aluminum powder used can be reduced by 21.8% compared with the actual production, and the comprehensive production cost of low-titanium ferro can be reduced by 12.5% per ton.

Claims

1. A method for preparing low-titanium ferroalloy by reducing ilmenite, characterized in that: The method comprises the following steps: S1 will reduce ilmenite, ilmenite concentrate, lime three reaction raw materials in advance at a certain temperature and dry standby; S2. The reaction raw materials are reduced ilmenite, ilmenite concentrate, lime, aluminum powder, iron powder are mixed in a certain proportion and placed in a thermite reactor. A certain proportion of the combustion aid is spread on the surface of the mixture, ignited by an igniter, and the thermite reduction reaction is initiated; S3. The product obtained from the thermite reaction in step S2 is cooled to room temperature and sorted to obtain a low-titanium ferroalloy and slag; S4. Grinding the low-titanium ferroalloy obtained in step S3 under protective agent conditions to obtain a low-titanium ferroalloy product with a certain mesh size.

2. The method for preparing low-titanium ferroalloy by reducing ilmenite according to claim 1, characterized in that: In step S1, the TiO2 content in the reduced ilmenite is 54-60%, and the TiO2 content in the titanium concentrate is 51-57%.

3. The method for preparing low-titanium ferroalloy by reducing ilmenite according to claim 1, characterized in that: In step S1, the drying temperature of the reduced ilmenite and ilmenite concentrate is 120-150° C. and the drying time is 8-12 hours, and the drying temperature of the lime is 80-100° C. and the drying time is 8-12 hours; the particle size of the reduced ilmenite and ilmenite concentrate is 80-120 mesh, and the particle size of the lime is 200-400 mesh.

4. The method for preparing low-titanium ferroalloy by reducing ilmenite according to claim 1, characterized in that: In step S2, the particle size of the aluminum powder is 80-100 mesh, the particle size of the iron powder is 80-100 mesh, the mixing time of the reaction raw materials should be ≤5 minutes, the combustion aid is sodium chlorate or potassium chlorate or a mixture of the two, and the ignition agent is magnesium strips or calcium powder.

5. The method for preparing low-titanium ferroalloy by reducing ilmenite according to claim 1, characterized in that: In step S3, the thermal reaction products are manually sorted to select low-titanium ferroalloy and slag after crushing.

6. The method for preparing low-titanium ferroalloy by reducing ilmenite according to claim 1, characterized in that: In step S4, the protective agent used is a water-based solution, whose main components are deionized water (accounting for 85-95%), a lubricant (polyethylene glycol, 3-5%), a rust remover (triethanolamine, accounting for 3-5%), an antioxidant (benzotriazole, accounting for 0.1-0.4%, a borate, accounting for 1-2%), and a pH adjuster (sodium hydroxide, accounting for 0-1%). The grinding time is 1-2 hours.

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