Method for refining titanium tetrachloride

Abstract

The invention relates to the technical field of titanium tetrachloride preparation, in particular to a method for refining titanium tetrachloride, which is characterized in that an organic vanadium removal agent is added into a secondary distillation kettle, so that iron-containing high-boiling-point substances discharged from a primary distillation kettle can directly return to a chlorination furnace, and a slurry evaporation furnace is only used for distilling vanadium-containing high-boiling-point substances discharged from the secondary distillation kettle; therefore, the load of the slurry evaporation furnace is reduced; the grade of the vanadium slag evaporated by the slurry evaporation furnace can be improved, the take-out price of the vanadium slag is increased, and the income is increased; scaling of solid-phase objects on heating equipment can be reduced, the heating efficiency is improved, the service time of the heating equipment is prolonged, meanwhile, the opportunity that the solid-phase objects adhere to a conveying pipeline can be reduced, and the blocking risk is reduced; the chance that the vanadium removal agent, ferric chloride and other substances are sintered on a high-temperature electric heater is reduced, the use amount of the vanadium removal agent is reduced, the discharge amount of high-boiling-point slag is reduced, and meanwhile titanium tetrachloride with the ultralow carbon content is produced.

Description

Technical Field

[0001] The invention relates to the technical field of titanium tetrachloride preparation, in particular to a method for refining titanium tetrachloride. Background Art

[0002] Titanium tetrachloride (TiCl 4 ) is an intermediate product for the production of titanium dioxide, titanium sponge and titanium series products. It is mainly produced by the reaction of high-titanium slag with chlorine at high temperature to form titanium tetrachloride. Industrial crude titanium tetrachloride usually contains a variety of impurities, mainly VOC1 3 and Fe chloride, etc., need to enter the refining system for impurity removal and purification. 3 The boiling point of vanadium is 127.2℃, which is close to the boiling point of titanium tetrachloride 136.4℃. It is difficult to separate it by general physical distillation method. At present, chemical method is generally used to remove vanadium. Among them, organic matter has high efficiency and low cost in removing vanadium, and is widely used at home and abroad.

[0003] The vanadium removal mechanism is that the organic vanadium removal agent is cracked into highly active fine carbon particles at high temperature. The new carbon particles can remove VOC1 3 Reduced to high boiling point VOC1 2 , and then remove vanadium through physical distillation. At present, there are still a lot of Fe chlorides in crude titanium tetrachloride. If it is carried out in the same space as the vanadium removal reaction, the vanadium slag will be mixed with a large amount of other solid phases, and it will also cause serious scaling of the heating equipment in the refining system, which will cause a significant decrease in thermal efficiency, and will also cause pipeline blockage and scaling cleaning problems of heating equipment. Summary of the invention

[0004] The object of the present invention is to provide a method for refining titanium tetrachloride to solve the problem that there is still a large amount of Fe chloride in the crude titanium tetrachloride mentioned in the above background technology. If it is carried out in the same space as the vanadium removal reaction, the vanadium slag will be mixed with a large amount of other solid phases, and at the same time it will cause serious scaling of the heating equipment of the refining system, thereby causing a significant decrease in thermal efficiency, and will also cause pipeline blockage and the problem of scaling cleaning of the heating equipment.

[0005] To achieve the above object, the present invention provides a method for refining titanium tetrachloride, comprising the steps of:

[0006] S1, adding the crude titanium tetrachloride after natural sedimentation into the primary distillation kettle, and physically refining it by controlling the temperature to remove high boiling point impurities such as iron-containing ferric chloride;

[0007] S2, discharge the iron-containing high-boiling-point substances from the bottom of the primary distillation kettle and return them to the chlorination furnace for recovery;

[0008] S3, the material in the primary distillation kettle enters the primary distillation tower after distillation, the top temperature of the primary distillation tower is controlled, and the chlorides of silicon and tin with low boiling points are removed;

[0009] S4, inputting the titanium tetrachloride treated by the primary distillation tower into a primary distillation kettle, adding an organic vanadium removal agent into the primary distillation kettle to promote the conversion of vanadium-containing compounds into high-boiling-point substances;

[0010] S5, discharging vanadium-containing high-boiling-point substances from the bottom of the primary distillation kettle, and recovering titanium tetrachloride therein through a slurry evaporation furnace, while the residual substances are collected as high-grade vanadium slag, and an organic vanadium removal agent is added to remove vanadium-containing impurities;

[0011] S6. The titanium tetrachloride treated in the primary distillation kettle is distilled into a primary distillation tower, and finally input into a secondary refining system for further refining to obtain high-purity titanium tetrachloride.

[0012] As a preferred embodiment of the present invention, the temperature in the primary distillation kettle is controlled within a range such that high-boiling chlorides with a boiling point greater than 136 degrees are discharged from the bottom of the kettle; the top temperature of the primary distillation tower is controlled within a range such that low-boiling chlorides such as silicon and tin are in a gaseous state, while titanium tetrachloride is in a liquid state; the organic vanadium removal agent added to the primary distillation kettle reacts with vanadium-containing impurities to generate high-boiling substances which are discharged from the bottom of the kettle; and the secondary refining system performs final refining on the titanium tetrachloride to obtain high-purity refined titanium tetrachloride.

[0013] As a preferred embodiment of the present invention, the top of the primary distillation tower is connected to a first condenser, a low-boiling-point material tank, and a second condenser in sequence. When the temperature in the primary distillation kettle is raised to more than 136 degrees, titanium tetrachloride vapor carries low-boiling-point impurities into the primary distillation tower, and then enters the low-boiling-point material tank through the liquefaction process of the first condenser.

[0014] As a preferred embodiment of the present invention, a primary high boiling point material tank is connected to the bottom of the primary distillation kettle, and one side of the primary high boiling point material tank is connected to a chlorination furnace.

[0015] As a preferred embodiment of the present invention, the top of the primary distillation kettle is connected to a primary distillation tower, and the titanium tetrachloride in the reflux pipe of the primary distillation tower is transferred to the reflux upper part of the primary distillation tower through a pipeline, and the top temperature of the tower is controlled to be 125-136 degrees, so that the vanadium-containing liquid titanium tetrachloride flows into the secondary distillation kettle after distillation.

[0016] As a preferred embodiment of the present invention, a primary high boiling point material tank is connected to the bottom of the primary distillation kettle, and one side of the primary high boiling point material tank is connected to the mud evaporation furnace.

[0017] As a preferred embodiment of the present invention, the secondary refining system includes a secondary distillation kettle and a secondary distillation tower.

[0018] As a preferred embodiment of the present invention, the titanium tetrachloride refluxed through the reflux pipe of the primary distillation tower enters the secondary distillation kettle for re-refining. The titanium tetrachloride refined again in the secondary distillation kettle is treated in a low-temperature brine condenser and finally discharged into the refined titanium tank to obtain a refined titanium tetrachloride product.

[0019] As a preferred embodiment of the present invention, the bottom of the secondary distillation kettle is connected to a secondary high boiling point material tank, one side of the secondary high boiling point material tank is connected to a mud evaporation furnace, vanadium-containing high boiling point materials are discharged from the bottom of the secondary distillation kettle, and titanium tetrachloride therein is recovered by the mud evaporation furnace, while the residual material is collected as high-grade vanadium slag, and an organic vanadium removal agent is added to remove vanadium-containing impurities.

[0020] As a preferred embodiment of the present invention, valves are installed at the bottoms of the primary distillation kettle, the first-stage distillation kettle and the second-stage distillation kettle.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. In the method for refining titanium tetrachloride, by adding an organic vanadium removal agent into the secondary distillation kettle, the iron-containing high-boiling-point substances discharged from the primary distillation kettle can be directly returned to the chlorination furnace, and the mud evaporation furnace is only used to distill the vanadium-containing high-boiling-point substances discharged from the secondary distillation kettle, thereby reducing the load of the mud evaporation furnace; the grade of the vanadium slag evaporated from the mud evaporation furnace can be improved, and the takeaway price of the vanadium slag can be increased to increase the profit; the scaling of solid phase in the heating equipment can be reduced, the heating efficiency can be improved, and the service life of the heating equipment can be extended, and the chance of solid phase adhering to the conveying pipeline can be reduced, and the risk of blockage can be reduced; the chance of the vanadium removal agent reacting with substances such as ferric chloride can be reduced, the amount of the vanadium removal agent can be reduced, and the discharge amount of high-boiling-point slag can be reduced, and titanium tetrachloride with ultra-low carbon content can be produced at the same time.

[0023] 2. In the method for refining titanium tetrachloride, the feeding position of the vanadium removal agent is changed from the primary distillation kettle to the primary distillation kettle, and the iron-containing high-boiling-point substances and the vanadium-containing high-boiling-point substances are discharged separately. The iron-containing high-boiling-point substances can be directly returned to the chlorination furnace to recover the titanium tetrachloride therein, while the vanadium-containing high-boiling-point substances are recovered from the titanium tetrachloride therein through the mud evaporation furnace, and high-grade solid vanadium slag is produced at the same time.

[0024] 3. In the method for refining titanium tetrachloride, scaling of the primary distillation kettle heating equipment is avoided by optimizing the feeding position of the vanadium removal agent. At the same time, the solid phase in the primary distillation kettle is greatly reduced, reducing the probability of scaling of the solid phase on the heating equipment, thereby improving the heat transfer efficiency and extending the service life of the heating equipment.

[0025] 4. In the method for refining titanium tetrachloride, by controlling the tower top temperature, the titanium tetrachloride content in the low-boiling-point substances is reduced and the refining yield is improved through two-stage refining in the primary tower and the first-stage tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 It is a structural schematic diagram of a primary distillation tower in the present invention;

[0028] Figure 3 It is a schematic diagram of the structure of the three-stage distillation tower in the present invention;

[0029] The meaning of each number in the figure is:

[0030] 1. Primary still; 11. Primary high-boiling-point tank; 2. Primary distillation tower; 21. First condenser; 22. Low-boiling-point tank; 23. Second condenser; 3. Primary still; 31. Primary high-boiling-point tank; 4. Primary distillation tower; 5. Secondary still; 51. Secondary high-boiling-point tank; 6. Secondary distillation tower; 61. Low-temperature brine condensation tank; 62. Refined titanium tank; 7. Mud evaporation furnace; 8. Chlorination furnace. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention provides a method for refining titanium tetrachloride, such as Figure 1-Figure 3 As shown, the following steps are included:

[0033] S1, adding crude titanium tetrachloride after natural sedimentation into primary distillation kettle 1, and physically refining by controlling the temperature to remove high boiling point impurities such as iron-containing ferric chloride;

[0034] S2, discharge the iron-containing high-boiling-point substances from the bottom of the primary distillation kettle 1, and return them to the chlorination furnace 8 for recovery;

[0035] S3, the material in the primary distillation kettle 1 enters the primary distillation tower 2 after distillation, the top temperature of the primary distillation tower 2 is controlled, and the chlorides of silicon and tin with low boiling points are removed;

[0036] S4. The titanium tetrachloride treated by the primary distillation tower 2 is input into the primary distillation kettle 3, and an organic vanadium removal agent is added into the primary distillation kettle 3 to promote the conversion of vanadium-containing compounds into high-boiling point substances; the vanadium removal agent is an organic vanadium removal agent, mineral oil, animal oil, cyclohexane acid and other organic substances, and the organic vanadium removal agent is cracked into active small particle carbon at high temperature, and the active carbon reduces vanadium trichloride to vanadium dichloride. The boiling point of vanadium dichloride is quite different from that of titanium tetrachloride, and it can be removed by distillation.

[0037] S5, discharging vanadium-containing high-boiling-point substances from the bottom of the primary distillation kettle 3, and recovering titanium tetrachloride therein through the mud evaporation furnace 7, and collecting the residual substances as high-grade vanadium slag, adding an organic vanadium removal agent, and removing vanadium-containing impurities;

[0038] S6. The titanium tetrachloride treated in the primary distillation kettle 3 is distilled into the primary distillation tower 4, and finally input into the secondary refining system for further refining to obtain high-purity refined titanium tetrachloride.

[0039] The method first uses a primary distillation kettle to remove high-boiling impurities such as iron-containing ferric chloride through physical refining, effectively reducing the impurity content in titanium tetrachloride. Subsequently, in the primary distillation tower, by controlling the top temperature of the tower, low-boiling chlorides such as silicon and tin are further removed, thereby improving the purity of titanium tetrachloride. In the primary distillation kettle, by adding an organic vanadium removal agent, vanadium-containing compounds are converted into high-boiling substances, which is convenient for subsequent separation and recovery. This step not only improves the vanadium removal efficiency, but also avoids the doping of a large amount of solid phase in the vanadium slag, and reduces the scaling and clogging problems of the heating equipment in the refining system.

[0040] The high-boiling-point substances containing vanadium discharged from the bottom of the primary distillation kettle are recycled through a slurry evaporation furnace, which not only recovers the titanium tetrachloride therein, but also obtains high-grade vanadium slag. In this process, the effective utilization and recycling of resources are realized, and the economic benefits of the enterprise are improved. After further refining in the three-stage refining system, a high-purity refined titanium tetrachloride product is finally obtained. The entire refining process has a clear flow and reasonable steps, which ensures the stability and consistency of product quality. This method reduces waste emissions and environmental pollution through effective impurity removal and resource recycling, which meets the requirements of green chemistry and sustainable development.

[0041] In this embodiment, the temperature in the primary distillation kettle 1 is controlled within a range such that high-boiling-point chlorides with a boiling point greater than 136 degrees are discharged from the bottom of the kettle; the top temperature of the primary distillation tower 2 is controlled within a range such that low-boiling-point chlorides such as silicon and tin are in a gaseous state, while titanium tetrachloride is in a liquid state; the organic vanadium removal agent added to the secondary distillation kettle 3 reacts with vanadium-containing impurities to generate high-boiling-point substances which are discharged from the bottom of the kettle; and the tertiary refining system performs final refining on the titanium tetrachloride to obtain high-purity refined titanium tetrachloride.

[0042] Specifically, the top of the primary distillation tower 2 is connected to the first condenser 21, the low-boiling-point material tank 22, and the second condenser 23 in sequence. When the temperature in the primary distillation kettle 1 is raised to more than 136 degrees, titanium tetrachloride vapor carries low-boiling-point impurities into the primary distillation tower 2, and then enters the low-boiling-point material tank 22 through the liquefaction process of the first condenser 21, and then enters the second condenser 23.

[0043] Furthermore, a primary high boiling point material tank 11 is connected to the bottom of the primary distillation kettle 1 , and one side of the primary high boiling point material tank 11 is connected to the chlorination furnace 8 .

[0044] Furthermore, a secondary distillation tower 4 is connected to the top of the secondary distillation kettle 3, and the liquid titanium tetrachloride mixture collected in the low-boiling-point material tank 22 is transferred to the upper part of the secondary distillation tower 4 through a pipeline, and the top temperature of the tower is controlled to be 115 degrees, so that the vanadium-containing liquid titanium tetrachloride flows into the secondary distillation kettle 3 after distillation.

[0045] Furthermore, a secondary high boiling point material tank 31 is connected to the bottom of the secondary distillation kettle 3 , and one side of the secondary high boiling point material tank 31 is connected to the mud evaporation furnace 7 .

[0046] Furthermore, the three-stage refining system includes a three-stage distillation kettle 5 and a three-stage rectification tower 6, which are used for further refining operations to improve the accuracy of material preparation.

[0047] Furthermore, the titanium tetrachloride refluxed through the reflux pipe of the secondary distillation tower 4 enters the tertiary distillation kettle 5 for further refining. The titanium tetrachloride further refined in the tertiary distillation kettle 5 is treated in the low-temperature brine condensation tank 61 and finally discharged into the refined titanium tank 62 to obtain a refined titanium tetrachloride product.

[0048] Furthermore, a third-stage high-boiling-point material tank 51 is connected to the bottom of the third-stage distillation kettle 5, and one side of the third-stage high-boiling-point material tank 51 is connected to the mud evaporation furnace 7. The vanadium-containing high-boiling-point material is discharged from the bottom of the third-stage distillation kettle 5, and the titanium tetrachloride therein is recovered by the mud evaporation furnace 7, and the residual material is collected as high-grade vanadium slag, and an organic vanadium removal agent is added to remove vanadium-containing impurities.

[0049] Furthermore, valves are installed at the bottom of the primary distillation kettle 1, the secondary distillation kettle 3 and the tertiary distillation kettle 5 to facilitate the control of material discharge and closing operations.

[0050] It is worth noting that the bottom temperature of the three distillation towers is controlled at 130-150 degrees, the bottom pressure is controlled at 5-50kPa, the top temperature of the primary tower is controlled at 115-125 degrees, the top pressure is controlled at 0-10kPa, and the top temperature of the other two distillation towers is controlled at 120-140 degrees, and the top pressure is controlled at 0-10kPa.

[0051] Finally, it should be noted that the electronic components of the slurry evaporation furnace 7, chlorination furnace 8, etc. in this embodiment are all universal standard parts or parts known to those skilled in the art, and their structures and principles can be known to those skilled in the art through technical manuals or through conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires respectively, and the specific connection means should refer to the working sequence between the electrical components in the above-mentioned working principle to complete the electrical connection, which are all well-known technologies in the art.

[0052] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for refining titanium tetrachloride, characterized in that: The steps include: S1, adding the crude titanium tetrachloride after natural sedimentation into the primary distillation kettle (1), and physically refining by controlling the temperature to remove the high boiling point impurity iron chloride; S2, discharging the iron-containing high-boiling-point substances from the bottom of the primary distillation kettle (1) and returning them to the chlorination furnace (8) for titanium tetrachloride recovery; S3, the material in the primary distillation kettle (1) enters the primary distillation tower (2) after distillation, the top temperature of the primary distillation tower (2) is controlled, and chlorides of silicon, tin, etc. with low boiling points are removed; S4, inputting the titanium tetrachloride treated in the primary distillation tower (2) into the primary distillation kettle (3), adding an organic vanadium removal agent into the primary distillation kettle (3) to promote the conversion of the vanadium-containing compound into a vanadium-containing high-boiling-point substance; S5, discharging vanadium-containing high-boiling-point substances from the bottom of the primary distillation kettle (3), and recovering titanium tetrachloride therein through a slurry evaporation furnace (7), while the residual substances are collected as high-grade vanadium slag, and an organic vanadium removal agent is added to remove vanadium-containing impurities in the crude titanium tetrachloride; S6. The titanium tetrachloride treated in the primary distillation kettle (3) is distilled into a primary distillation tower (4), and finally input into a secondary refining system for further refining to obtain high-purity refined titanium tetrachloride.

2. The method for refining titanium tetrachloride according to claim 1, characterized in that: The temperature in the primary distillation kettle (1) is controlled within a range such that high-boiling chlorides with a boiling point greater than 136 degrees are discharged from the bottom of the kettle; the top temperature of the primary distillation tower (2) is controlled within a range such that low-boiling chlorides such as silicon and tin are in a gaseous state, while titanium tetrachloride is in a liquid state; the organic vanadium removal agent added to the primary distillation kettle (3) reacts with vanadium-containing impurities to generate high-boiling substances which are discharged from the bottom of the kettle; and the secondary refining system performs final refining on the titanium tetrachloride to obtain high-purity refined titanium tetrachloride.

3. The method for refining titanium tetrachloride according to claim 2, characterized in that: The top of the primary distillation tower (2) is connected in sequence to a first condenser (21), a low-boiling-point material tank (22), and a second condenser (23). When the temperature in the primary distillation kettle (1) rises to more than 136 degrees, titanium tetrachloride vapor carrying low-boiling-point impurities enters the primary distillation tower (2), and the tower top temperature is controlled at 125-136 degrees. Then, the vapor passes through the first condenser (21) for liquefaction and enters the low-boiling-point material tank (22).

4. The method for refining titanium tetrachloride according to claim 1, characterized in that: The bottom of the primary distillation kettle (1) is connected to a primary high-boiling-point substance tank (11), and one side of the primary high-boiling-point substance tank (11) is connected to a chlorination furnace (8).

5. The method for refining titanium tetrachloride according to claim 3, characterized in that: The top of the primary distillation kettle (3) is connected to a primary distillation tower (4), and the vanadium-containing liquid titanium tetrachloride is distilled from the reflux pipe of the primary distillation tower (2) through a pipeline and then transferred to the primary distillation kettle (3), and the tower top temperature is controlled to be 125-136 degrees, so that the low-boiling-point substances in the distilled crude titanium tetrachloride are further removed after being refined by the primary distillation tower (4) and condensed (41) at the tower top.

6. The method for refining titanium tetrachloride according to claim 1, characterized in that: The bottom of the primary distillation kettle (3) is connected to a primary high boiling point material tank (31), and one side of the primary high boiling point material tank (31) is connected to a slurry evaporation furnace (7).

7. The method for refining titanium tetrachloride according to claim 1, characterized in that: The three-stage refining system includes a secondary distillation kettle (5) and a secondary distillation tower (6).

8. The method for refining titanium tetrachloride according to claim 7, characterized in that: The titanium tetrachloride refluxed through the reflux pipe of the primary distillation tower (4) enters the secondary distillation kettle (5) for further refining. The titanium tetrachloride that has been further refined in the secondary distillation kettle (5) is taken out through the reflux pipe, condensed into refined titanium, and finally discharged into the refined titanium tank (62) after being treated in the low-temperature brine condensation tank (61) to obtain a refined titanium tetrachloride product.

9. The method for refining titanium tetrachloride according to claim 8, characterized in that: The bottom of the secondary distillation kettle (5) is connected to a secondary high boiling point material tank (51), and one side of the secondary high boiling point material tank (51) is connected to a slurry evaporation furnace (7). Vanadium-containing high boiling point materials are discharged from the bottom of the secondary distillation kettle (5), and titanium tetrachloride is recovered from the slurry evaporation furnace (7), while the residual materials are collected as high-grade vanadium slag.

10. The method for refining titanium tetrachloride according to claim 7, characterized in that: Valves are installed at the bottom of the primary still (1), the first still (3) and the second still (5).

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