A process for the production of titanium tetrachloride in a fluid bed

Abstract

The application provides a method for preparing titanium tetrachloride by using a fluidized bed, wherein the powder fluidization area and the cooling area are alternately arranged in the fluidized bed, the whole is in a rectangular structure, the powder material is added from one side of the fluidized bed, and is sequentially overflowed through several fluidization areas and cooling areas and then discharged from the outlet; the fluidization gas enters the fluidized bed through the distribution plate at the bottom of the fluidization area, and reacts with the added powder particles at a certain temperature to prepare titanium tetrachloride; and the cooling medium is sent from the bottom of the fluidized bed and discharged from the top outlet after heat exchange. The method uses the slag containing titanium carbide, titanium nitride or titanium carbonitride as the raw material, and reacts with chlorine gas, so that the reaction efficiency is high; the fluidized bed adopts the cross design of the fluidization area and the cooling area, so that the heat released by the chlorination reaction is discharged from the fluidized bed through the cooling medium in time, and the local heat release of the reaction is avoided, and the sintering of the material or even the dead furnace condition is avoided.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and specifically to a method for preparing titanium tetrachloride using a fluidized bed. Background Technology

[0002] Currently, the main method for producing titanium tetrachloride is the fluidized bed chlorination process. This involves mixing TiO2-rich titanium raw materials with petroleum coke in a specific ratio, adding chlorine gas, and conducting a closed chemical reaction in a chlorination furnace. The reaction temperature is generally above 900℃, and titanium tetrachloride is obtained after the reaction. However, due to the natural endowment of titanium-bearing ores in my country, the natural raw ore is mainly vanadium-titanium magnetite, which has a high calcium and magnesium content. The processing cost of titanium raw materials requiring TiO2 ≥ 90% and CaO + MgO ≤ 1.5% for the traditional fluidized bed chlorination process is high, the process is lengthy, and the process is difficult.

[0003] After years of dedicated research, a process route for simultaneously preparing titanium tetrachloride from titanium-containing blast furnace slag has gradually been formed, primarily based on a "high-temperature carbonization-low-temperature chlorination" process. Patent CN201610191369.4 discloses a method for preparing titanium tetrachloride, which pre-classifies the carbonized slag for different particle sizes and uses different fluidized bed chlorination processes in different fluidized bed chlorination reactors to improve the efficiency of fluidized bed chlorination of the carbonized slag. Patent CN202010862320.3 discloses a method for chlorinating carbonized slag using multiple chlorination units in a single fluidized bed chlorination reactor. All of these patents suffer from drawbacks such as complex fluidized bed chlorination reactor structures, independent operating parameters for each unit, high operational difficulty, large exothermic reaction between carbonized slag and chlorine, and potential furnace sintering failure. Summary of the Invention

[0004] In view of this, the present invention proposes a method for preparing titanium tetrachloride in a fluidized bed, which further improves equipment reliability, enhances heat exchange, reduces sintering, and lowers the production cost of titanium tetrachloride.

[0005] To achieve the above objectives, this invention provides a method for preparing titanium tetrachloride using a fluidized bed structure. The fluidized bed includes alternating powder fluidization and cooling zones, and the overall structure of the fluidized bed is rectangular. The method includes the following steps:

[0006] The powder material is added from one side of the fluidized bed, and after passing through several fluidization zones and cooling zones, it is discharged from the outlet.

[0007] The fluidizing gas enters the fluidized bed through the distribution plate at the bottom of the fluidizing zone and reacts with the added powder particles at a set temperature to prepare titanium tetrachloride;

[0008] The cooling medium is fed into the fluidized bed from the bottom and discharged from the top outlet after heat exchange.

[0009] As a further aspect of the present invention, the powder composition is slag containing titanium carbide, titanium nitride, or titanium carbonitride; the particle size range of the powder is 0 to 0.2 mm.

[0010] As a further aspect of the present invention, the total content of titanium carbide, titanium nitride, or titanium carbonitride in the slag is 10% to 100%.

[0011] As a further embodiment of the present invention, the powder is prepared using slag containing 13.5-14.5% titanium carbide as raw material in a fluidized bed reactor, which is connected to a cyclone dust collector and a spray condenser.

[0012] As a further aspect of the present invention, the slag crushing yields powder with particle sizes of <0.019mm accounting for 5%, 0.019-0.038mm accounting for 40%, 0.038-0.075mm accounting for 43%, and >0.075mm accounting for 12%.

[0013] As a further aspect of the present invention, the fluidizing gas is a mixture of chlorine and nitrogen, and the chlorine flow rate is set to 102 m³ / s. 3 Adjust the nitrogen flow rate to control the fluidizing gas velocity to 0.05–0.07 m / s per hour.

[0014] As a further embodiment of the present invention, the slag feeding rate is set to 1t / h, and after being preheated to 480℃, it is fed into the fluidized bed from the powder inlet; the cooling medium is air, and the temperature of the reaction section is controlled at 500℃~550℃.

[0015] As a further embodiment of the present invention, the fluidizing gas in the fluidized bed is a mixture of chlorine and nitrogen, with a fluidizing gas velocity ranging from 0.05 to 0.40 m / s, and is fed into the fluidized bed through a gas distribution plate.

[0016] As a further embodiment of the present invention, the cooling medium is air, nitrogen, water vapor, or water.

[0017] As a further aspect of the present invention, the fluidization zone and the cooling zone are respectively set to have the same or different thicknesses according to the heat released by the chlorination reaction.

[0018] In the fluidized bed preparation method of the present invention, the fluidized bed has a simple structure, ingenious design, and is easy to control. It uses slag containing titanium carbide, titanium nitride, or titanium carbonitride as raw material, and has high reaction efficiency. By alternating the arrangement of fluidized and cooling zones, the heat release of the reaction is effectively managed, reducing the risk of local overheating, and realizing a high-efficiency production process for preparing titanium tetrachloride, thereby reducing the production cost of titanium tetrachloride.

[0019] Compared with existing technologies, the fluidized bed method for preparing titanium tetrachloride proposed in this invention has the following advantages:

[0020] The fluidized bed method for preparing titanium tetrachloride of the present invention has a simple, ingeniously designed, and easily controlled fluidized bed structure; it uses slag containing titanium carbide, titanium nitride, or titanium carbonitride as raw material to react with chlorine gas, resulting in high reaction efficiency; the fluidized bed adopts a cross-design of fluidizing and cooling zones, which allows the heat released by the chlorination reaction to be discharged from the fluidized bed in a timely manner through the cooling medium, avoiding the occurrence of large local heat release during the reaction, which could lead to material sintering or even furnace failure.

[0021] These or other aspects of this application will become more apparent from the following description of embodiments. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0023] In the diagram:

[0024] Figure 1 This is a schematic diagram of the structure of a fluidized bed in which a cold medium inlet enters the fluidized bed in a method for preparing titanium tetrachloride according to an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the fluidized bed in which the heat medium inlet enters the fluidized bed in a method for preparing titanium tetrachloride in a fluidized bed according to an embodiment of the present invention. Detailed Implementation

[0026] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0028] It should be noted that all uses of the terms "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two different entities or different parameters with the same name. Therefore, "first" and "second" are merely for convenience of expression and should not be construed as limiting the embodiments of the present invention. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as other steps or units inherent in a process, method, apparatus, product, or device that includes a series of steps or units.

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0031] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0032] Existing processes for the simultaneous preparation of titanium tetrachloride from titanium-containing blast furnace slag all suffer from unfavorable factors such as complex fluidized bed chlorination reactor structure, independent operating parameters for each unit, high operational difficulty, large heat release from the reaction between carbonized slag and chlorine, and furnace dead-end due to sintering inside the furnace.

[0033] In view of this, the present invention proposes a method for preparing titanium tetrachloride in a fluidized bed, which further improves equipment reliability, enhances heat exchange, reduces sintering, and lowers the production cost of titanium tetrachloride.

[0034] See Figure 1 and Figure 2 As shown, this invention provides a method for preparing titanium tetrachloride using a fluidized bed. The method employs a novel fluidized bed, in which powder fluidization zones and cooling zones are alternately arranged, forming a rectangular structure. Powder material is added from one side of the fluidized bed, overflows through several fluidization and cooling zones, and is discharged from the outlet. Fluidizing gas enters the fluidized bed through a distribution plate at the bottom of the fluidization zones, reacting with the added powder particles at a certain temperature to prepare titanium tetrachloride. Cooling medium is introduced from the bottom of the fluidized bed, exchanges heat, and is discharged from the top outlet.

[0035] The powder material mainly consists of slag containing titanium carbide, titanium nitride, or titanium carbonitride, with a particle size of 0-0.2 mm, and the combined content of titanium carbide, titanium nitride, or titanium carbonitride is 10%-100%. The fluidizing gas is a mixture of chlorine and nitrogen, with a fluidizing gas velocity of 0.05-0.40 m / s, and is fed into the fluidized bed through a gas distribution plate. The cooling medium includes air, nitrogen, water vapor, and water. The fluidizing zone and cooling zone should be set to the same or different thicknesses according to the heat released by the chlorination reaction.

[0036] In the fluidized bed preparation method of the present invention, the fluidized bed has a simple structure, ingenious design, and is easy to control. It uses slag containing titanium carbide, titanium nitride, or titanium carbonitride as raw material, and has high reaction efficiency. By alternating the arrangement of fluidized and cooling zones, the heat release of the reaction is effectively managed, reducing the risk of local overheating, and realizing a high-efficiency production process for preparing titanium tetrachloride, thereby reducing the production cost of titanium tetrachloride.

[0037] The present invention will be further illustrated below with reference to the embodiments. The embodiments are only used to illustrate the present invention and are not intended to limit the invention in any way.

[0038] Example 1

[0039] This invention provides a method for preparing titanium tetrachloride in a fluidized bed, comprising the following steps:

[0040] In the preparation stage, the slag is first crushed to obtain powder with particle sizes of <0.019mm (5%), 0.019-0.038mm (40%), 0.038-0.075mm (43%), and >0.075mm (12%), which is then placed in the raw material silo for later use. The fluidizing gas is a mixture of chlorine and nitrogen, with the chlorine flow rate set at 102 m³ / h. 3 The nitrogen flow rate is adjusted to control the fluidizing gas velocity at 0.05–0.07 m / s; the slag feed rate is set to 1 t / h, and after preheating to 480℃, it is fed into the fluidized bed through the powder inlet; the cooling medium is air, and the temperature of the reaction section is controlled at 500℃–550℃; the generated crude titanium tetrachloride is collected by cyclone dust collection and spray condensation to obtain crude titanium, which is then stored in the crude titanium storage tank.

[0041] Example 2

[0042] This invention provides a method for preparing titanium tetrachloride in a fluidized bed, comprising the following steps:

[0043] In the preparation stage, the slag is first crushed to obtain powder with particle sizes of <0.045mm (10%), 0.045-0.075mm (36%), 0.075-0.15mm (38%), and >0.15mm (16%), which is then placed in the raw material silo for later use. The fluidizing gas is a mixture of chlorine and nitrogen, with the chlorine flow rate set at 102 m³ / h. 3 The nitrogen flow rate is adjusted to control the fluidizing gas velocity at 0.10–0.12 m / s; the slag feed rate is set to 1 t / h, and after preheating to 480℃, it is fed into the fluidized bed from the powder inlet; the cooling medium is air, and the temperature of the reaction section is controlled at 500℃–550℃; the generated crude titanium tetrachloride is collected by cyclone dust collection and spray condensation to obtain crude titanium, which is then stored in the crude titanium storage tank.

[0044] Example 3

[0045] This invention provides a method for preparing titanium tetrachloride in a fluidized bed, comprising the following steps:

[0046] In the preparation stage, the slag is first crushed to obtain powder with particle sizes of <0.075mm (5%), 0.075-0.15mm (41%), 0.15-0.25mm (44%), and >0.25mm (10%), which is then placed in the raw material silo for later use. The fluidizing gas is a mixture of chlorine and nitrogen, with the chlorine flow rate set at 102 m³ / h. 3 The nitrogen flow rate is adjusted to control the fluidizing gas velocity at 0.35–0.40 m / s; the slag feed rate is set to 1 t / h, and after preheating to 480℃, it is fed into the fluidized bed through the powder inlet; the cooling medium is air, and the temperature of the reaction section is controlled at 500℃–550℃; the generated crude titanium tetrachloride is collected by cyclone dust collection and spray condensation to obtain crude titanium, which is then stored in the crude titanium storage tank.

[0047] In summary, the fluidized bed method for preparing titanium tetrachloride of the present invention features a simple, ingeniously designed, and easily controlled fluidized bed structure; it utilizes slag containing titanium carbide, titanium nitride, or titanium carbonitride as raw material to react with chlorine gas, resulting in high reaction efficiency; the fluidized bed employs a cross-design of fluidizing and cooling zones, ensuring that the heat released by the chlorination reaction is promptly discharged from the fluidized bed through the cooling medium, thus avoiding excessive local heat release during the reaction, which could lead to material sintering or even furnace failure.

[0048] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0049] It should be understood that, as used herein, the singular form "a" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the associatedly listed items. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0050] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A process for the production of titanium tetrachloride in a fluidized bed, characterized in that, The method is characterized in that a fluidized bed structure is adopted, the fluidized bed comprises powder fluidization areas and cooling areas arranged alternately, and the overall structure of the fluidized bed is rectangular; the method comprises the following steps: The powder material is added from a first side of the fluidized bed, and is discharged from an outlet on a second side of the fluidized bed after sequentially overflowing through the alternately arranged fluidization areas and cooling areas; The fluidization gas enters the fluidized bed through a distribution plate at the bottom of the fluidization area, and reacts with the added powder particles at a set temperature to prepare titanium tetrachloride; The cooling medium is fed from the bottom of the fluidized bed, and is discharged from the top outlet after heat exchange, the first side and the second side are two opposite sides of the rectangular overall structure and are on different sides of the bottom and the top of the fluidized bed.

2. The process for fluidized bed production of titanium tetrachloride according to claim 1, characterized in that, The powder ingredient is a slag containing titanium carbide, titanium nitride or titanium carbonitride; the particle size of the powder ranges from 0 to 0.2 mm.

3. The process for fluidized bed production of titanium tetrachloride according to claim 2, characterized in that, The content of titanium carbide, titanium nitride or titanium carbonitride in the slag ranges from 10% to 100%.

4. The process for fluidized bed production of titanium tetrachloride according to claim 3, characterized in that, The powder is prepared by using a slag containing 13.5-14.5% of titanium carbide as raw material in a fluidized bed reactor, and the fluidized bed reactor is connected with a cyclone dust collector and a spray condensing device.

5. The process for fluidized bed production of titanium tetrachloride according to claim 4, characterized in that, The slag is crushed to obtain a powder with a particle size of <0.019 mm accounting for 5%, 0.019-0.038 mm accounting for 40%, 0.038-0.075 mm accounting for 43% and >0.075 mm accounting for 12%.

6. The process for fluidized bed production of titanium tetrachloride according to claim 5, characterized in that, The fluidizing gas is a mixture of chlorine and nitrogen, the chlorine flow rate is 102 m 3 / h, the nitrogen flow rate is adjusted to control the fluidizing gas velocity to be 0.05-0.07 m / s.

7. The process for the fluidized bed production of titanium tetrachloride according to claim 6, characterized in that, The slag is fed into the fluidized bed at a rate of 1 t / h after being preheated to 480°C; the cooling medium is air, and the temperature of the reaction section is controlled to be 500-550°C.

8. The process for the fluidized bed production of titanium tetrachloride according to claim 7, characterized in that, The fluidization gas in the fluidized bed is a mixed gas of chlorine and nitrogen, and the fluidization gas velocity ranges from 0.05 to 0.40 m / s, which is fed into the fluidized bed through a gas distribution plate.

9. The process for fluidized bed production of titanium tetrachloride according to claim 1, characterized in that, The cooling medium is air, nitrogen, water vapor or water.

10. The process for fluidized bed production of titanium tetrachloride according to claim 1, characterized in that, The fluidization areas and the cooling areas are arranged to have the same or different thicknesses according to the heat release of the chlorination reaction.

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