Titanium tetrachloride refining raffinate pretreatment system for removing vanadium from aluminum powder and use method of titanium tetrachloride refining raffinate pretreatment system

Abstract

The invention discloses an aluminum powder vanadium removal titanium tetrachloride refining residual liquid pretreatment system and a use method thereof. The system comprises a reaction tank and a lye tank which are connected, the reaction tank is provided with two outlets, one outlet is connected with the production tail gas treatment unit through an exhaust pipe, and the other outlet is communicated with the settling tank; a metering charging pump is arranged on a connecting pipeline between the lye tank and the reaction tank, and an exhaust valve is arranged on the exhaust pipe; the tank cover of the reaction tank is also provided with a pressure controller; and a NaOH solution is stored in the lye tank. The treatment method can be suitable for the high-impurity-content raffinate generated in the refining process of titanium tetrachloride with vanadium removed through aluminum powder, under the condition of lower alkali liquor concentration, the treatment time is effectively shortened, the equipment corrosion strength is remarkably relieved, and the treatment efficiency of the titanium tetrachloride refining raffinate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of titanium tetrachloride production, and more specifically to a pretreatment system for aluminum powder vanadium-removed titanium tetrachloride refined residual liquid and a use method thereof. Background Art

[0002] In the production process of titanium tetrachloride, crude titanium tetrachloride usually contains impurities such as iron, vanadium, and aluminum, which need to be refined and purified to meet product quality requirements. Among them, aluminum powder vanadium removal is a commonly used refining method, but this method will introduce aluminum chloride impurities during the vanadium removal process. Since the refined residual liquid after aluminum powder vanadium removal still contains a large amount of titanium tetrachloride, it must be recycled.

[0003] At present, there are two main treatment methods for the titanium tetrachloride refined residual liquid after vanadium removal from aluminum powder: one is to return it directly to the chlorination process for reuse; the other is to evaporate it after pre-treatment by hydrolysis with water. Among them, the hydrolysis pre-treatment method can effectively separate the aluminum impurities in the residual liquid. However, a large amount of heat will be released during the hydrolysis reaction, and high-temperature acidic gas will be generated, which not only puts extremely high requirements on the corrosion resistance of the hydrolysis equipment, but also increases the difficulty of selecting the equipment material. The Chinese patent with application number 201410420827.8 discloses a method for removing impurities from crude titanium tetrachloride using alkali solution, but the treatment object it is applicable to is a crude titanium tetrachloride gas-liquid mixture or liquid, and is not applicable to the slag-liquid mixture containing high impurities such as aluminum trichloride and vanadium dichloride obtained during the refining treatment of titanium tetrachloride. At the same time, the concentration of the alkali solution used is relatively high, at a concentration of 30%-60%. In addition, the contact time between the alkali solution and the crude titanium tetrachloride is 1-20 minutes. Chinese patent application number 202220486547.7 discloses a tail gas treatment device for the production of titanium tetrachloride by the molten salt chlorination method, but the tail gas it is applicable to is the tail gas generated in the titanium tetrachloride production process, and salt water is produced during the treatment process and needs to be discharged.

[0004] In view of the above problems, it is necessary to improve the pretreatment method of the titanium tetrachloride refined residual liquid for removing vanadium from aluminum powder. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a pretreatment system for aluminum powder vanadium removal titanium tetrachloride refined residual liquid and a use method thereof, which is used to pretreat the refined residual liquid with a high impurity content generated in the aluminum powder vanadium removal titanium tetrachloride refining process, and can effectively reduce the processing time and the corrosion intensity of the processing process to the equipment.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] A pretreatment system for aluminum powder vanadium removal titanium tetrachloride refined residual liquid, the system comprises a connected reaction tank 1 and an alkali solution tank 2; the reaction tank 1 is provided with two outlets, one of which is connected to a production tail gas treatment unit 4 through an exhaust pipe 5, and the other is connected to a sedimentation tank 3; a metering feed pump 6 is provided on the connecting pipeline between the alkali solution tank 2 and the reaction tank 1, and an exhaust valve is provided on the exhaust pipe 5; the tank cover of the reaction tank 1 is also provided with a pressure controller; and the alkali solution tank 2 stores NaOH solution.

[0008] Optionally, the reaction tank 1, the alkali solution tank 2 and the sedimentation tank 3 are all closed containers.

[0009] The present invention also discloses a method for using the aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system as described above, comprising the following steps:

[0010] The titanium tetrachloride refined residual liquid is transported to the reaction tank 1 through the titanium tetrachloride refined residual liquid transport pipeline 7 by a mud pump, and the NaOH solution stored in the alkali liquid tank 2 is added to the titanium tetrachloride refined residual liquid transport pipeline 7 through a metering feed pump 6, mixed with the titanium tetrachloride refined residual liquid, and then transported to the reaction tank 1 together, so that the NaOH solution reacts in the titanium tetrachloride refined residual liquid transport pipeline 7 and the reaction tank 1 to generate Al2O3 precipitation and HCl gas, wherein most of the HCl gas is neutralized with NaOH to generate NaCl and water;

[0011] When the pressure in the reaction tank 1 is greater than 0.1 MPa, the exhaust valve automatically opens to allow the waste gas generated by the reaction to enter the production tail gas treatment unit 4 through the exhaust pipe 5, until the pressure in the reaction tank 1 is less than or equal to 0.1 MPa, the exhaust valve automatically closes;

[0012] The materials obtained by the reaction are transported to the sedimentation tank 3 for treatment.

[0013] Optionally, the concentration of the NaOH solution is 10% to 25%.

[0014] Optionally, the mass ratio of the added amount of the NaOH solution to the theoretical reaction amount of AlCl3 in the refined titanium tetrachloride residual liquid is 1.0 to 5.0:1.

[0015] Optionally, when the refined titanium tetrachloride residual liquid is transported to the reaction tank 1, the amount of NaOH solution added is continuously added in proportion to the flow rate of the refined titanium tetrachloride residual liquid in the pipeline, and the addition port of the NaOH solution on the refined titanium tetrachloride residual liquid transport pipeline 7 is close to the reaction tank 1.

[0016] Optionally, the time for the NaOH solution to mix and react with the titanium tetrachloride refined residual liquid in the titanium tetrachloride refined residual liquid conveying pipeline 7 is less than 1 min.

[0017] Optionally, the method further comprises: separating the materials obtained by the reaction after being treated in a sedimentation tank 3 .

[0018] Implementing the embodiments of the present invention will have the following beneficial effects:

[0019] The present invention aims at the problem that the equipment is highly corrosive and the material requirements of the equipment are high during the pretreatment process of adding water to the titanium tetrachloride refined residual liquid for removing vanadium from aluminum powder, and an improved pretreatment system and a method for using the same are proposed. In the method, a NaOH solution is accurately measured and added to the pipeline for conveying the titanium tetrachloride refined residual liquid to the reaction tank. In the reaction tank, NaOH reacts with impurities such as AlCl3 and a small amount of TiCl4 in the residual liquid to generate precipitations such as Al2O3 and HCl gas, and the generated HCl gas is further neutralized with NaOH to generate NaCl. When the waste gas pressure generated in the reaction tank exceeds the set value, it can be discharged to the production tail gas treatment unit through the exhaust pipe. The treatment method of the present invention can be applied to the residual liquid with high impurity content generated in the process of refining titanium tetrachloride for removing vanadium from aluminum powder, and under the condition of lower alkali solution concentration, the treatment time is effectively reduced and the corrosion intensity of the equipment is significantly reduced; in addition, by using the NaOH solution for pretreatment, the AlCl3 and high-boiling-point impurities in the residual liquid can be quickly removed, and the treatment efficiency of the titanium tetrachloride refined residual liquid is improved. At the same time, the method reduces the requirements for the materials of the pretreatment reaction tank and the supporting equipment, and reduces the risk of equipment blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention is a schematic diagram of the aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system.

[0021] Among them, 1. reaction tank, 2. alkali liquid tank, 3. sedimentation tank, 4. production tail gas treatment unit, 5. exhaust pipe, 6. metering feed pump, 7. titanium tetrachloride refined residual liquid transportation pipeline. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited in any way.

[0023] The invention discloses a pretreatment system for aluminum powder vanadium-removing titanium tetrachloride refined residual liquid, the system comprises a connected reaction tank 1 and an alkali liquid tank 2; the reaction tank 1 is provided with two outlets, one of which is connected to a production tail gas treatment unit 4 through an exhaust pipe 5, and the other is connected to a sedimentation tank 3; a metering feed pump 6 is provided on a connecting pipeline between the alkali liquid tank 2 and the reaction tank 1, and an exhaust valve is provided on the exhaust pipe 5; a tank cover of the reaction tank 1 is also provided with a pressure controller; and a NaOH solution is stored in the alkali liquid tank 2.

[0024] In a specific embodiment, the reaction tank 1, the alkali solution tank 2 and the sedimentation tank 3 are all closed containers.

[0025] The present invention also discloses a method for using the above-mentioned aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system, comprising the following steps: using a slurry pump to transport the titanium tetrachloride refined residual liquid to a reaction tank 1 through a titanium tetrachloride refined residual liquid delivery pipeline 7, and at the same time, adding a NaOH solution stored in an alkali liquid tank 2 to the titanium tetrachloride refined residual liquid delivery pipeline 7 through a metering feed pump 6, and then mixing with the titanium tetrachloride refined residual liquid and transporting them to the reaction tank 1, so that the NaOH solution reacts in the titanium tetrachloride refined residual liquid delivery pipeline 7 and the reaction tank 1 to generate Al2O3 precipitation and HCl gas, wherein most of the HCl gas is neutralized with NaOH to generate NaCl and water;

[0026] When the pressure in the reaction tank 1 is greater than 0.1 MPa, the exhaust valve automatically opens, allowing the waste gas generated by the reaction to enter the production tail gas treatment unit 4 through the exhaust pipe 5, until the pressure in the reaction tank 1 is less than or equal to 0.1 MPa, the exhaust valve automatically closes;

[0027] The materials obtained by the reaction are transported to the sedimentation tank 3 for treatment.

[0028] In a specific embodiment, the concentration of the NaOH solution is 10% to 25%.

[0029] In a specific embodiment, the mass ratio of the amount of NaOH solution added to the theoretical reaction amount of AlCl3 in the titanium tetrachloride refined residual liquid is 1.0-5.0:1.

[0030] In a specific embodiment, when the refined titanium tetrachloride residual liquid is transported to the reaction tank 1, the amount of NaOH solution added is continuously added in proportion to the flow rate of the refined titanium tetrachloride residual liquid in the pipeline, and the addition port of the NaOH solution on the refined titanium tetrachloride residual liquid transport pipeline 7 is close to the reaction tank 1.

[0031] In a specific embodiment, the time for the NaOH solution to mix and react with the titanium tetrachloride refined residual liquid in the titanium tetrachloride refined residual liquid conveying pipeline 7 is less than 1 minute.

[0032] In a specific embodiment, the method further comprises: treating the material obtained by the reaction in a sedimentation tank 3 and then performing separation treatment.

[0033] The following are specific embodiments

[0034] Example 1

[0035] The aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system of this embodiment comprises a connected alkali liquid tank 2 and a reaction tank 1; the reaction tank 1 is provided with two outlets, one of which is connected to the production tail gas treatment unit 4 through an exhaust pipe 5, and the other is connected to the sedimentation tank 3; a metering feed pump 6 is provided on the connecting pipeline between the alkali liquid tank 2 and the reaction tank 1, and an exhaust valve is provided on the exhaust pipe 5; the tank cover of the reaction tank 1 is also provided with a pressure controller; and a NaOH solution is stored in the alkali liquid tank 2. Among them, the reaction tank 1, the alkali liquid tank 2 and the sedimentation tank 3 are all closed containers.

[0036] The method for using the pretreatment system of the present embodiment comprises the following steps: using a mud pump to transport the titanium tetrachloride refined residual liquid to the reaction tank 1 through the titanium tetrachloride refined residual liquid delivery pipeline 7, and at the same time, adding the NaOH solution stored in the alkali liquid tank 2 to the titanium tetrachloride refined residual liquid delivery pipeline 7 through the metering feed pump 6, mixing with the titanium tetrachloride refined residual liquid, and then transporting them to the reaction tank 1 together, so that the NaOH solution reacts in the titanium tetrachloride refined residual liquid delivery pipeline 7 and the reaction tank 1 to generate Al2O3 precipitation and HCl gas, wherein most of the HCl gas is neutralized with NaOH to generate NaCl and water, and the materials obtained by the reaction are treated in the sedimentation tank 3; when the pressure in the reaction tank 1 is greater than 0.1MPa, opening the exhaust valve to allow the waste gas generated by the reaction to enter the production tail gas treatment unit 4 through the exhaust pipe 5, until the pressure in the reaction tank 1 is ≤0.1MPa, closing the exhaust valve.

[0037] The concentration of the NaOH solution is 18%.

[0038] The mass ratio of the added amount of NaOH solution to the theoretical reaction amount of AlCl3 in the titanium tetrachloride refined residual liquid is 1.6:1.

[0039] When the titanium tetrachloride refined residual liquid is transported to the reaction tank 1, it is continuously added in proportion according to the flow rate of the titanium tetrachloride refined residual liquid in the pipeline.

[0040] Among them, the reaction time is less than 1min.

[0041] When the feeding of the reaction tank 1 is completed and the pressure in the reaction tank 1 is stabilized, it indicates that the pretreatment reaction of the titanium tetrachloride refined residual liquid is completed, and the titanium tetrachloride refined residual liquid is treated by the separation unit.

[0042] Example 2

[0043] The aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system of this embodiment comprises a connected alkali liquid tank 2 and a reaction tank 1; the reaction tank 1 is provided with two outlets, one of which is connected to the production tail gas treatment unit 4 through an exhaust pipe 5, and the other is connected to the sedimentation tank 3; a metering feed pump 6 is provided on the connecting pipeline between the alkali liquid tank 2 and the reaction tank 1, and an exhaust valve is provided on the exhaust pipe 5; the tank cover of the reaction tank 1 is also provided with a pressure controller; and a NaOH solution is stored in the alkali liquid tank 2. Among them, the reaction tank 1, the alkali liquid tank 2 and the sedimentation tank 3 are all closed containers.

[0044] The method for using the pretreatment system of the present embodiment comprises the following steps: using a mud pump to transport the titanium tetrachloride refined residual liquid to the reaction tank 1 through the titanium tetrachloride refined residual liquid delivery pipeline 7, and at the same time, adding the NaOH solution stored in the alkali liquid tank 2 to the titanium tetrachloride refined residual liquid delivery pipeline 7 through the metering feed pump 6, mixing with the titanium tetrachloride refined residual liquid, and then transporting them to the reaction tank 1 together, so that the NaOH solution reacts in the titanium tetrachloride refined residual liquid delivery pipeline 7 and the reaction tank 1 to generate Al2O3 precipitation and HCl gas, wherein most of the HCl gas is neutralized with NaOH to generate NaCl and water, and the materials obtained by the reaction are treated in the sedimentation tank 3; when the pressure in the reaction tank 1 is greater than 0.1MPa, opening the exhaust valve to allow the waste gas generated by the reaction to enter the production tail gas treatment unit 4 through the exhaust pipe 5, until the pressure in the reaction tank 1 is ≤0.1MPa, closing the exhaust valve.

[0045] The concentration of the NaOH solution is 25%.

[0046] The mass ratio of the added amount of NaOH solution to the theoretical reaction amount of AlCl3 in the titanium tetrachloride refined residual liquid is 2.0:1.

[0047] When the titanium tetrachloride refined residual liquid is transported to the reaction tank 1, it is continuously added in proportion according to the flow rate of the titanium tetrachloride refined residual liquid in the pipeline.

[0048] The reaction time is less than 1 minute. Specifically, due to the small amount of alkali solution used, the titanium tetrachloride refined residual liquid and the NaOH solution are quickly mixed in the pipeline and the reaction is completed.

[0049] When the feeding of the reaction tank 1 is completed and the pressure in the reaction tank 1 is stabilized, it indicates that the pretreatment reaction of the titanium tetrachloride refined residual liquid is completed, and the titanium tetrachloride refined residual liquid is treated by the separation unit.

[0050] Example 3

[0051] The aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system of this embodiment comprises a connected alkali liquid tank 2 and a reaction tank 1; the reaction tank 1 is provided with two outlets, one of which is connected to the production tail gas treatment unit 4 through an exhaust pipe 5, and the other is connected to the sedimentation tank 3; a metering feed pump 6 is provided on the connecting pipeline between the alkali liquid tank 2 and the reaction tank 1, and an exhaust valve is provided on the exhaust pipe 5; the tank cover of the reaction tank 1 is also provided with a pressure controller; and a NaOH solution is stored in the alkali liquid tank 2. Among them, the reaction tank 1, the alkali liquid tank 2 and the sedimentation tank 3 are all closed containers.

[0052] The method for using the pretreatment system of the present embodiment comprises the following steps: using a mud pump to transport the titanium tetrachloride refined residual liquid to the reaction tank 1 through the titanium tetrachloride refined residual liquid delivery pipeline 7, and at the same time, adding the NaOH solution stored in the alkali liquid tank 2 to the titanium tetrachloride refined residual liquid delivery pipeline 7 through the metering feed pump 6, mixing with the titanium tetrachloride refined residual liquid, and then transporting them to the reaction tank 1 together, so that the NaOH solution reacts in the titanium tetrachloride refined residual liquid delivery pipeline 7 and the reaction tank 1 to generate Al2O3 precipitation and HCl gas, wherein most of the HCl gas is neutralized with NaOH to generate NaCl and water, and the materials obtained by the reaction are treated in the sedimentation tank 3; when the pressure in the reaction tank 1 is greater than 0.1MPa, opening the exhaust valve to allow the waste gas generated by the reaction to enter the production tail gas treatment unit 4 through the exhaust pipe 5, until the pressure in the reaction tank 1 is ≤0.1MPa, closing the exhaust valve.

[0053] The concentration of the NaOH solution is 10%.

[0054] The mass ratio of the added amount of NaOH solution to the theoretical reaction amount of AlCl3 in the titanium tetrachloride refined residual liquid is 3.5:1.

[0055] When the titanium tetrachloride refined residual liquid is transported to the reaction tank 1, it is continuously added in proportion according to the flow rate of the titanium tetrachloride refined residual liquid in the pipeline.

[0056] The reaction time is less than 1 minute. Specifically, due to the small amount of alkali solution used, the titanium tetrachloride refined residual liquid and the NaOH solution are quickly mixed in the pipeline and the reaction is completed.

[0057] When the feeding of the reaction tank 1 is completed and the pressure in the reaction tank 1 is stabilized, it indicates that the pretreatment reaction of the titanium tetrachloride refined residual liquid is completed, and the titanium tetrachloride refined residual liquid is treated by the separation unit.

[0058] The device and method for pretreating the aluminum powder vanadium-removing titanium tetrachloride refined residual liquid of the present invention can increase the sedimentation rate of various high-boiling-point impurities in the aluminum powder vanadium-removing titanium tetrachloride refined residual liquid and improve the treatment efficiency.

[0059] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A pretreatment system for aluminum powder vanadium removal titanium tetrachloride refined residual liquid, characterized in that: The system comprises a reaction tank (1) and an alkali solution tank (2) connected to each other; The reaction tank (1) is provided with two outlets, one of which is connected to the production tail gas treatment unit (4) through the exhaust pipe (5), and the other is connected to the sedimentation tank (3); A metering feed pump (6) is provided on the connecting pipeline between the alkali liquid tank (2) and the reaction tank (1), and an exhaust valve is provided on the exhaust pipe (5); The tank cover of the reaction tank (1) is also provided with a pressure controller; The alkali solution tank (2) stores NaOH solution.

2. The aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system according to claim 1 is characterized in that: The reaction tank (1), the alkali solution tank (2) and the sedimentation tank (3) are all closed containers.

3. A method for using the aluminum powder vanadium removal titanium tetrachloride refined residual liquid pretreatment system as claimed in any one of claims 1 to 2, characterized in that: The following steps are involved: The titanium tetrachloride refined residual liquid is transported to the reaction tank (1) through the titanium tetrachloride refined residual liquid transport pipeline (7) by a mud pump, and at the same time, the NaOH solution stored in the alkali solution tank (2) is added to the titanium tetrachloride refined residual liquid transport pipeline (7) through a metering feed pump (6), mixed with the titanium tetrachloride refined residual liquid, and then transported to the reaction tank (1) together, so that the NaOH solution reacts in the titanium tetrachloride refined residual liquid transport pipeline (7) and the reaction tank (1) to generate Al2O3 precipitation and HCl gas, wherein most of the HCl gas is neutralized with NaOH to generate NaCl and water; When the pressure in the reaction tank (1) is greater than 0.1 MPa, the exhaust valve automatically opens, allowing the waste gas generated by the reaction to enter the production tail gas treatment unit (4) through the exhaust pipe (5), until the pressure in the reaction tank (1) is less than or equal to 0.1 MPa, the exhaust valve automatically closes; The materials obtained by the reaction are transported to a sedimentation tank (3) for treatment.

4. The method of use according to claim 3, characterized in that: The concentration of the NaOH solution is 10% to 25%.

5. The method of use according to claim 3, characterized in that: The mass ratio of the added amount of the NaOH solution to the theoretical reaction amount of AlCl3 in the refined titanium tetrachloride residual liquid is (1.0-5.0):

1.

6. The method of use according to claim 3, characterized in that: When the refined titanium tetrachloride residual liquid is transported to the reaction tank (1), the amount of NaOH solution added is continuously added in proportion to the flow rate of the refined titanium tetrachloride residual liquid in the pipeline, and the addition port of the NaOH solution on the refined titanium tetrachloride residual liquid transport pipeline (7) is close to the reaction tank (1).

7. The method of use according to claim 3, characterized in that: The time for the NaOH solution to mix and react with the titanium tetrachloride refined residual liquid in the titanium tetrachloride refined residual liquid conveying pipeline (7) is less than 1 minute.

8. The method of use according to claim 3, characterized in that: The method further comprises: treating the material obtained by the reaction in a sedimentation tank (3) and then performing separation treatment.

Images