Vanadium removal method of synergistic catalyst for crude titanium tetrachloride

Abstract

The invention relates to a vanadium removal method of a synergistic catalyst for crude titanium tetrachloride, and belongs to the technical field of organic matter refined titanium tetrachloride. Mixing and stirring an organic matter and crude titanium tetrachloride at normal temperature to obtain a mixed solution; adding a synergistic catalyst into the mixed solution, heating to 100-130 DEG C, and stirring for 1-4 hours for full reaction; wherein the synergistic catalyst is composed of an oxide carrier, a metal chloride complexing agent and active metal; and continuing to heat to 140-160 DEG C to distill the titanium tetrachloride to obtain fine titanium tetrachloride and residues easy to treat. By optimizing the selection of the organic matters and adding the synergistic catalyst, the generation of agglomerated carbon-containing small molecules can be reduced, and the carbon content in the titanium sponge is reduced, so that the rigidity and the production quality of the titanium sponge are improved.

Description

Technical Field

[0001] The invention relates to a method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst, belonging to the technical field of refining titanium tetrachloride from organic matter. Background Art

[0002] The purification of titanium tetrachloride is a key step in the production of high-quality titanium dioxide and titanium sponge. In this process, the organic refining method is widely used because of its abundant raw materials, low cost, non-toxicity and simple operation, but this method also has some challenges. One of the main problems is that the carbon content in the produced titanium sponge is too high, which is mainly due to the different structures of the residues produced by the reaction of different types of organic matter with crude titanium tetrachloride. Commonly used organic matter, such as fatty acids and vegetable oils, are easy to form carbon-containing small molecules due to their lower cracking temperature. These small molecules are four times enriched in titanium sponge as the refined titanium tetrachloride volatilizes, resulting in a decrease in the rigidity of titanium sponge and affecting its production quality. In addition, the residues produced by commonly used organic reagents such as fatty acids and vegetable oils are not easy to remove, which increases the complexity of the production process. Selecting organic species that are not easy to crack can reduce the generation of carbon-containing small molecules and residues, but this will slow down the vanadium removal rate and may increase production costs. In order to solve these problems, it is particularly important to invent an efficient synergistic catalytic reagent. This synergistic catalytic reagent can increase the cracking rate of organic matter, thereby reducing the amount of organic matter used and changing the structure of the residue.

[0003] Quan Hui et al., with publication number CN111087017A, invented a method for removing vanadium from crude titanium tetrachloride. In the invention, cracked diesel is mixed with hydrogen, and then hydrogenated in the presence of a hydrogenation catalyst. The reaction effluent is separated to obtain a liquid phase material; the crude titanium tetrachloride and the liquid phase material are countercurrently contacted in an evaporation tower to perform a sufficient devanadium reaction. The present invention uses a composition rich in ideal vanadium removal components to achieve an excellent vanadium removal effect on titanium tetrachloride, solving the technical problem of using organic matter to remove vanadium in the existing process, which produces a large amount of residue that affects heat transfer. The invention discloses the hydrogenation reaction conditions as shown in Table 1.

[0004] Table 1

[0005]

[0006] The distillation range of the catalytic cracking diesel of the invention with publication number CN111087017A is 150°C to 370°C. The reaction temperature of the hydrogenation catalyst is high when removing vanadium, resulting in high energy consumption and high cost, which is not conducive to actual production. In addition, the hydrogen catalyst is added to the catalytic cracking diesel, which increases the production cost and slows down the vanadium removal efficiency. The present invention can achieve more efficient organic matter cracking in the refining process of titanium tetrachloride, reduce residue generation, and reduce the carbon content in sponge titanium by developing and applying efficient synergistic catalytic reagents, thereby improving the rigidity and production quality of sponge titanium, which is of great significance for the production of high-quality titanium dioxide and sponge titanium. Summary of the invention

[0007] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst. The present invention can reduce the generation of agglomerated carbon-containing small molecules and reduce the carbon content in titanium sponge by optimizing the selection of organic matter and adding a synergistic catalyst, thereby improving the rigidity and production quality of titanium sponge. The present invention is achieved through the following technical solutions.

[0008] A method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0009] (1) mixing an organic substance and crude titanium tetrachloride at room temperature and stirring to obtain a mixed solution;

[0010] (2) adding a synergistic catalyst to the mixed solution, heating it to 100-130° C., and stirring it for 1-4 hours to fully react; wherein the synergistic catalyst is composed of an oxide carrier, a metal chloride complexing agent, and a small amount of active metal;

[0011] (3) Continue to raise the temperature to 140-160° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily-handled residue.

[0012] The organic matter in step (1) is one of hydrocarbon polymers, oil organic matter, hydrocarbon chain organic matter or a mixture of any proportions thereof, and the mass ratio of the organic matter to the crude titanium tetrachloride is 0.5 to 3:1000.

[0013] The hydrocarbon-containing polymer in step (1) is polyethylene, polypropylene or polyvinyl chloride.

[0014] The oily organic matter in step (1) is mineral oil, animal oil, vegetable oil or oleic acid.

[0015] The oxide carrier in the synergistic catalyst in step (2) is Al 2 O 3 The amount of oxide support added is such that the mass ratio of oxide support to crude titanium tetrachloride is 0.1 to 2.5:1000.

[0016] In the step (2), the metal chloride complexing agent in the synergistic catalyst is a chloride containing a valence state change, and the chloride containing a valence state change is FeCl 2 、FeCl 3 , CuCl or CuCl 2 The mass ratio of the metal chloride complexing agent added to the crude titanium tetrachloride is 0.5 to 3:1000.

[0017] In the step (2), the active metal is Fe or Ti, and the mass ratio of the active metal added to the crude titanium tetrachloride is 0.5 to 2:1000.

[0018] The beneficial effects of the present invention are:

[0019] (1) The oxide carrier used in the synergistic catalyst of the present invention can accelerate the reaction rate and reduce the reaction temperature. In addition, the synergistic catalyst of the present invention can change the product structure, and the residue can be better processed, which is more conducive to the removal of vanadium from organic matter.

[0020] (2) The structure of the residue product of the present invention is changed, and the chain-like, large-pore residue morphology is generated, that is, the carbon-containing small molecules that are not easy to agglomerate, which will further reduce the carbon content in the sponge titanium in the later stage.

[0021] (3) The metal chloride complexing agent used in the synergistic catalyst of the present invention can better catalyze the decomposition of organic carbon and hydrogen atoms in the form of complexation due to the change in valence state, converting VOCl 3 Reduction to VOCl 2 or VCl 3 Remove vanadium.

[0022] (4) A small amount of metal can be used to reduce titanium tetrachloride to low-valent titanium TiCl under the action of other synergistic catalysts 3 , low-valent titanium will VOCl 3 Converted to VOCl 2 , promoting the vanadium removal rate.

[0023] (5) The synergistic catalyst used in the present invention mainly increases the vanadium removal rate and reduces the amount of organic matter by catalyzing the decomposition of organic matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a SEM morphology characterization diagram of the residue in Example 1 of the present invention;

[0025] Figure 2 This is a SEM morphology characterization diagram of the residue in Example 2 of the present invention;

[0026] Figure 3 This is a SEM morphology characterization diagram of the residue in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0028] Example 1

[0029] The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0030] (1) Organic matter (polyethylene organic matter containing hydrocarbon polymer) and 1000 g crude titanium tetrachloride (the V content of which is expressed as VOCl 3 Mainly, the volume ratio content is 0.002785%) according to the mass ratio of 2:1000 at room temperature to obtain a mixed solution;

[0031] (2) Add the synergistic catalyst to the mixed solution, raise the temperature to 115°C, and stir for 2 hours to fully react; the synergistic catalyst is Al 2 O 3 、FeCl 3 Mixed with a small amount of Fe to form a synergistic catalyst, the mass ratio of the oxide carrier to the crude titanium tetrachloride is 0.5:1000; the mass ratio of the metal chloride complexing agent added to the crude titanium tetrachloride is 1:1000; the mass ratio of the active metal added to the crude titanium tetrachloride is 0.5:1000;

[0032] (3) Continue to raise the temperature to 140° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily handled residue.

[0033] In this example, the obtained refined titanium tetrachloride was subjected to ICP detection of V element content. The detection results are shown in Table 2. It can be seen from Table 2 that the volume ratio of V element is 0.0000013%, and the vanadium removal rate is 99.95%.

[0034] The residue in this embodiment was characterized by SEM morphology, and the SEM morphology characterization diagram is as follows: Figure 1 As shown, the residue morphology is long-chain fiber.

[0035] Example 2

[0036] The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0037] (1) Organic matter (polypropylene organic matter containing hydrocarbon polymer) and 1000g crude titanium tetrachloride (the V content of which is expressed as VOCl 3 Mainly, the volume ratio content is 0.002785%) according to the mass ratio of 2:1000 at room temperature to obtain a mixed solution;

[0038] (2) Add the synergistic catalyst to the mixed solution, raise the temperature to 120°C, and stir for 2 hours to fully react; the synergistic catalyst is Al2 O 3 、FeCl 3 Mixed with a small amount of Fe to form a synergistic catalyst, the mass ratio of the oxide carrier to the crude titanium tetrachloride is 1:1000; the mass ratio of the metal chloride complexing agent added to the crude titanium tetrachloride is 1.5:1000; the mass ratio of the active metal added to the crude titanium tetrachloride is 0.5:1000;

[0039] (3) Continue to raise the temperature to 140° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily handled residue.

[0040] In this example, the refined titanium tetrachloride obtained was subjected to ICP detection of V element content. The detection results are shown in Table 2. It can be seen from Table 2 that the volume ratio of V element is 0.0000008%, and the vanadium removal rate is 99.97%.

[0041] The residue in this embodiment was characterized by SEM morphology, and the SEM morphology characterization diagram is as follows: Figure 2 As shown, the residue morphology is long chain short chain.

[0042] Example 3

[0043] The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0044] (1) Organic matter (oleic acid organic matter of oil) and 1000g crude titanium tetrachloride (the V content of which is expressed as VOCl 3 Mainly, the volume ratio content is 0.002785%) according to the mass ratio of 1.5:1000 at room temperature to mix and stir to obtain a mixed solution;

[0045] (2) Add the synergistic catalyst to the mixed solution, raise the temperature to 100°C, and stir for 1 hour to fully react; the synergistic catalyst is Al 2 O 3 、FeCl 3 Mixed with a small amount of Fe to form a synergistic catalyst, the mass ratio of the oxide carrier to the crude titanium tetrachloride is 1:1000; the mass ratio of the metal chloride complexing agent added to the crude titanium tetrachloride is 2:1000; the mass ratio of the active metal added to the crude titanium tetrachloride is 1:1000;

[0046] (3) Continue to raise the temperature to 140° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily handled residue.

[0047] In this example, the refined titanium tetrachloride obtained was subjected to ICP detection of V element content. The detection results are shown in Table 2. It can be seen from Table 2 that the volume ratio of V element is 0.0000018%, and the vanadium removal rate is 99.94%.

[0048] Comparative Example 1

[0049] The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0050] (1) Organic matter (polyethylene organic matter containing hydrocarbon polymer) and 1000 g crude titanium tetrachloride (the V content of which is expressed as VOCl 3 Mainly, the volume ratio content is 0.002785%) according to the mass ratio of 4:1000 at room temperature to mix and stir to obtain a mixed solution;

[0051] (2) Add Al to the mixture 2 O 3 , heating to 115°C, stirring for 2 hours to fully react; wherein the mass ratio of the oxide support to the crude titanium tetrachloride is 2:1000;

[0052] (3) Continue to raise the temperature to 140° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily handled residue.

[0053] In this comparative example, the refined titanium tetrachloride obtained was subjected to ICP detection of V element content. The detection results are shown in Table 2. It can be seen from Table 2 that the volume ratio of V element is 0.0000432%, and the vanadium removal rate is 98.45%.

[0054] The residue in this embodiment was characterized by SEM morphology, and the SEM morphology characterization diagram is as follows: Figure 3 As shown, the residue morphology is a long chain of spheres.

[0055] Comparative Example 2

[0056] The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0057] (1) Organic matter (polypropylene organic matter containing hydrocarbon polymer) and 1000g crude titanium tetrachloride (the V content of which is expressed as VOCl 3 Mainly, the volume ratio content is 0.002785%) according to the mass ratio of 5:1000 at room temperature to mix and stir to obtain a mixed solution;

[0058] (2) Add FeCl to the mixture 3 , heating to 120°C, stirring for 2 hours to fully react; wherein the mass ratio of the metal chloride complexing agent added to the crude titanium tetrachloride is 3:1000;

[0059] (3) Continue to raise the temperature to 140° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily handled residue.

[0060] In this example, the refined titanium tetrachloride obtained was subjected to ICP detection of V element content. The detection results are shown in Table 2. It can be seen from Table 2 that the volume ratio of V element is 0.0000263%, and the vanadium removal rate is 99.05%.

[0061] Comparative Example 3

[0062] The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst comprises the following steps:

[0063] (1) Organic matter (oleic acid organic matter of oil) and 1000g crude titanium tetrachloride (the V content of which is expressed as VOCl 3 Mainly, the volume ratio content is 0.002785%) according to the mass ratio of 5:1000 at room temperature to mix and stir to obtain a mixed solution;

[0064] (2) adding a small amount of Fe to the mixed solution, heating to 100°C, and stirring for 1 hour to fully react; wherein the mass ratio of the active metal added to the crude titanium tetrachloride is 1:1000;

[0065] (3) Continue to raise the temperature to 140° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily handled residue.

[0066] In this example, the refined titanium tetrachloride obtained was subjected to ICP detection of V element content. The detection results are shown in Table 2. It can be seen from Table 2 that the volume ratio of V element is 0.0000289%, and the vanadium removal rate is 98.96%.

[0067]

[0068] According to the results of the embodiments and comparative examples, it can be seen that when any one of the synergistic catalysts is added alone, the required organic content increases, and the resulting residue morphology is aggregated together through spherical connections, which is easy to produce small molecular carbon, and is easy to be enriched in the titanium sponge with the distillation of titanium tetrachloride. Adding three synergistic catalysts in different proportions at the same time reduces the amount of organic matter added, and the resulting residue morphology is chain-like, with large pores, and is not easy to agglomerate to form carbon-containing small molecules, thereby reducing the carbon content in the titanium sponge. The present invention discloses a method for removing vanadium from crude titanium tetrachloride using a synergistic catalytic agent, which catalyzes the cracking of stable carbon-hydrogen polymerized organic matter, effectively reduces the amount of organic matter added, changes the residue morphology, and reduces the carbon content in the titanium sponge.

[0069] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst, characterized in that the steps include: (1) mixing an organic substance and crude titanium tetrachloride at room temperature and stirring to obtain a mixed solution; (2) adding a synergistic catalyst to the mixed solution, heating it to 100-130° C., and stirring it for 1-4 hours to fully react; wherein the synergistic catalyst is composed of an oxide carrier, a metal chloride complexing agent, and an active metal; (3) Continue to raise the temperature to 140-160° C. to distill titanium tetrachloride to obtain refined titanium tetrachloride and an easily-handled residue.

2. The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst according to claim 1, wherein: The organic matter in step (1) is one of hydrocarbon polymers, oil organic matter, hydrocarbon chain organic matter or a mixture of any proportions thereof, and the mass ratio of the organic matter to the crude titanium tetrachloride is 0.5 to 3:1000.

3. The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst according to claim 2, wherein: The hydrocarbon-containing polymer in step (1) is polyethylene, polypropylene or polyvinyl chloride.

4. The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst according to claim 2, wherein: The oily organic matter in step (1) is mineral oil, animal oil, vegetable oil or oleic acid.

5. The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst according to claim 1, characterized in that: In the step (2), the oxide carrier in the synergistic catalyst is Al2O3, and the amount of the oxide carrier added is such that the mass ratio of the oxide carrier to the crude titanium tetrachloride is 0.1 to 2.5:1000.

6. The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst according to claim 1, characterized in that: In the step (2), the metal chloride complexing agent in the synergistic catalyst is FeCl2, FeCl3, CuCl or CuCl2, and the added amount of the metal chloride complexing agent is 0.5 to 3:1000 in mass ratio to the crude titanium tetrachloride.

7. The method for removing vanadium from crude titanium tetrachloride using a synergistic catalyst according to claim 1, characterized in that: In the step (2), the active metal is Fe or Ti, and the mass ratio of the active metal added to the crude titanium tetrachloride is 0.5 to 2:1000.

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