Vanadium removal reagent for removing vanadium impurities in titanium tetrachloride and use method of vanadium removal reagent

Abstract

The invention relates to the technical field of titanium tetrachloride, and provides a vanadium removal reagent for removing vanadium impurities in titanium tetrachloride and a use method of the vanadium removal reagent, the vanadium removal reagent is prepared from the following components in percentage by mass: 20-60% of anthracene compounds, 1-10% of phenanthrene compounds, 5-20% of pyrene compounds, 10-30% of thiophene compounds and 10-30% of naphthalene compounds, the sum of the mass percentages of all the components is 100%, and the vanadium removal reagent is used for reacting with vanadium oxychloride in titanium tetrachloride to remove vanadium impurities. According to the scheme, the defects that the vanadium removal efficiency is low, the speed is low, dangerous reagents are used and secondary carbon pollution is introduced in a traditional process are overcome, and the purity of the obtained titanium tetrachloride product completely meets the strict application requirements in the high-end field.

Description

Technical Field

[0001] This invention relates to the field of titanium tetrachloride technology, and more particularly to a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride and its method of use. Background Technology

[0002] Titanium tetrachloride is an indispensable chemical raw material in high-end fields such as aerospace, electronics, and metallurgy, and its purity directly determines the performance of downstream products. For example, the mechanical properties of titanium alloys used in aerospace and the transmission characteristics of optical fibers in the electronics field both place extremely stringent requirements on the purity of titanium tetrachloride raw materials. However, in the production process of titanium tetrachloride, the deep removal of vanadium impurities has always been a technical bottleneck restricting the improvement of product quality. This vanadium impurity mainly exists in the form of vanadium oxychloride (VOCl3). Due to its physicochemical properties, especially its boiling point, being very similar to those of titanium tetrachloride, and its relatively small difference in volatility, traditional physical separation methods such as distillation and rectification are difficult to achieve effective separation. Industry data shows that the vanadium impurity content in titanium tetrachloride produced by traditional processes is usually between 0.01% and 0.5%, far from meeting the extreme requirement of less than 0.0007% vanadium content in high-end applications.

[0003] In existing technologies, copper wire vanadium removal and hydrogen sulfide vanadium removal are commonly used to remove vanadium impurities, but both methods have significant drawbacks. Copper wire vanadium removal has a slow reaction rate and low vanadium removal efficiency, and requires a large amount of copper, resulting in high production costs and making it unsuitable for large-scale industrial production. Hydrogen sulfide vanadium removal involves the use of highly toxic hydrogen sulfide gas, posing a serious threat to production safety, operator health, and environmental protection. Furthermore, the sulfide precipitates generated during the reaction can easily clog equipment and pipelines, increasing the complexity and cost of system maintenance. Moreover, these methods can easily introduce new carbon impurities during vanadium removal due to the vanadium removal reagent itself or side reactions, leading to excessive carbon content in the product. The presence of carbon impurities significantly degrades the performance of titanium tetrachloride, for example, causing increased brittleness in the preparation of high-end titanium alloys, thus severely limiting its application in high-value fields.

[0004] Therefore, there is an urgent need for a vanadium removal reagent and its matching method that can efficiently and selectively remove vanadium impurities while avoiding the introduction of secondary pollution, especially carbon impurities. Summary of the Invention

[0005] In view of the problems of low vanadium removal efficiency, high production cost, and difficulty in meeting the needs of large-scale industrial production in the existing technology, as well as the easy introduction of new carbon impurities due to the vanadium removal reagent itself or side reactions during the removal of vanadium impurities, resulting in excessive carbon content in the product, the present invention provides a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride and its application method.

[0006] According to a first aspect of the present invention, the present invention provides a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride, comprising the following components in the indicated mass percentages: 20-60% anthracene compounds, 1-10% phenanthrene compounds, 5-20% pyrene compounds, 10-30% thiophene compounds, and 10-30% naphthalene compounds, wherein the sum of the mass percentages of the components is 100%, and the vanadium removal reagent is used to react with vanadium oxychloride in titanium tetrachloride to remove vanadium impurities.

[0007] In some embodiments, the anthracene compound is anthracene, the phenanthrene compound is phenanthrene, the pyrene compound is pyrene, the thiophene compound is thiophene, and the naphthalene compound is naphthalene.

[0008] In some embodiments, the thiophene compound is an alkylthiophene.

[0009] In some embodiments, the product comprises the following components in the following mass percentages: 40-50% anthracene compounds, 1-5% phenanthrene compounds, 5-10% pyrene compounds, 20-30% thiophene compounds, and 10-25% naphthalene compounds, wherein the sum of the mass percentages of the components is 100%.

[0010] According to a second aspect of the present invention, the present invention also provides a method of using a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride as described in any of the preceding claims, comprising: Step a: Pre-treat the vanadium removal reagent by heating it to 70-130℃; Step b: Mix the pretreated vanadium removal reagent with titanium tetrachloride containing vanadium oxychloride impurities, and stir the mixture at 136-140℃ for 0.5-4 hours. Step c: Distill the mixture after the reaction to obtain titanium tetrachloride with vanadium impurities removed.

[0011] In some embodiments, the mass ratio of the pretreated vanadium removal reagent in step b to titanium tetrachloride containing vanadium oxychloride impurities is 1:500 to 1:2000.

[0012] In some embodiments, the distillation separation in step c is atmospheric distillation, collecting the fraction at 136-140°C.

[0013] In some embodiments, after distillation in step c, the resulting titanium tetrachloride is further subjected to fractional distillation.

[0014] In some embodiments, the distillation is carried out in a packed column, wherein the packing in the packed column is stainless steel Pall rings, the top temperature of the column is controlled at 135-137°C, the bottom temperature of the column is controlled at 138-141°C, and the reflux ratio is 4:1 to 12:1.

[0015] In some embodiments, the pretreatment in step a and the reaction step in step b are carried out under inert gas protection.

[0016] The aforementioned vanadium removal reagent and its application method for removing vanadium impurities from titanium tetrachloride, through specific component compounding and optimized processes, synergistically achieve highly efficient and deep removal of vanadium impurities while eliminating the introduction of carbon impurities. The product has extremely high purity, and the process is safe and cost-controllable. Specifically, the specific ratios of anthracene, phenanthrene, pyrene, thiophene, and naphthalene compounds complement each other. Anthracene compounds form stable complexes, phenanthrene compounds enhance activity and regulate physical properties, pyrene compounds promote pyrolysis, thiophene compounds alter the reaction pathway through coordination, and naphthalene compounds improve dispersion and contact, collectively ensuring the high efficiency and selectivity of the reaction. In the accompanying application method, preheating ensures reagent activity, precise control of reaction temperature and time ensures complete reaction, and subsequent distillation achieves efficient product separation. Overall, the technical solution of this application overcomes the shortcomings of traditional processes, such as low vanadium removal efficiency, slow rate, use of hazardous reagents, and introduction of secondary carbon pollution. The purity of the obtained titanium tetrachloride product fully meets the stringent application requirements of high-end fields. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a flowchart illustrating a method for using a vanadium removal reagent to remove vanadium impurities from titanium tetrachloride, as provided in one embodiment of the present invention. Detailed Implementation

[0019] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0020] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0021] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Terms such as "including" or "contains" mean that the element preceding the word covers the element listed after the word, and do not exclude the possibility of covering other elements as well.

[0022] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0024] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.

[0025] According to a first aspect of the present invention, the present invention provides a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride, the vanadium removal reagent comprising the following components in mass percentages: 20-60% anthracene compounds, 1-10% phenanthrene compounds, 5-20% pyrene compounds, 10-30% thiophene compounds, and 10-30% naphthalene compounds, wherein the sum of the mass percentages of each component is 100%, the vanadium removal reagent being used to react with vanadium oxychloride in titanium tetrachloride to remove vanadium impurities.

[0026] The core of this invention lies in providing a composite vanadium removal reagent specifically designed to remove vanadium impurities (mainly in the form of vanadium oxychloride VOCl3) from titanium tetrachloride. This reagent is composed of a variety of polycyclic aromatic hydrocarbons and heterocyclic aromatic hydrocarbons with specific structures, formulated in precise proportions. Each component exerts a synergistic effect within the system. The specific ratios of anthracene, phenanthrene, pyrene, thiophene, and naphthalene compounds complement each other. Anthracene compounds form stable complexes, phenanthrene compounds enhance activity and regulate physical properties, pyrene compounds promote pyrolysis, thiophene compounds alter the reaction pathway through coordination, and naphthalene compounds improve dispersion and contact, collectively ensuring the high efficiency and selectivity of the reaction.

[0027] Specifically, anthracene compounds refer to compounds containing anthracene (C 14 H 10 Anthracene compounds, with their core structure, possess a conjugated structure formed by the fusion of three benzene rings. This conjugated large π-bond system readily undergoes electron transfer with VOCl3, enabling them to form stable complexes through electron transfer. Phenanthrene compounds (such as phenanthrene, C...) 14 H 10 The molecular structure is similar to anthracene compounds but with a different spatial configuration. It is an isomer of anthracene, and its different spatial configuration is used to regulate reactivity and reagent flowability. In reagent systems, it works synergistically with anthracene compounds to enhance the overall reactivity and selectivity of the reagent with VOCl3, and to adjust reagent viscosity; pyrene compounds (such as pyrene, C...) 16 H 10 ( ) Possesses a linear fused structure of four benzene rings, providing a larger molecular plane and adsorption capacity. It has a large conjugated system and strong adsorption capacity, and can form specific intermediates with VOCl3, promoting its cracking and carbonization. Thiophene compounds are a class of sulfur-containing heterocyclic aromatic hydrocarbons. The sulfur atoms in their molecules provide lone pairs of electrons, which can coordinate with vanadium ions. The sulfur atoms in thiophene compounds have lone pairs of electrons and high chemical reactivity. They can undergo coordination reactions with vanadium ions in VOCl3, changing the chemical properties of VOCl3 and promoting its cracking and carbonization reaction. Naphthalene compounds (such as naphthalene, C 10 H8) has a bicyclic structure. Naphthalene compounds have low boiling points and good solubility, which helps to dilute and promote dispersion. They can also adjust the physicochemical properties of the reagent and increase the contact area between the reagent and VOCl3. The sum of the mass percentages of all components is 100%.

[0028] As a more specific embodiment, a preferred formulation of the vanadium removal reagent comprises the following components in the following mass percentages: 40-50% anthracene compounds, 1-5% phenanthrene compounds, 5-10% pyrene compounds, 20-30% thiophene compounds, and 10-25% naphthalene compounds, wherein the sum of the mass percentages of each component is 100%. This preferred formulation range optimizes the synergistic effect of the components and maximizes the vanadium removal efficiency.

[0029] In some embodiments, to obtain optimal reaction results and operational characteristics, the anthracene compound is preferably high-purity anthracene, the phenanthrene compound is preferably phenanthrene, the pyrene compound is preferably pyrene, and the naphthalene compound is preferably naphthalene. Using these pure substances allows for precise control of the reaction and avoids unpredictable side reactions.

[0030] In other embodiments, the thiophene compound may be thiophene itself or a derivative thereof. For example, as a viable alternative, the thiophene compound may be an alkylthiophene, such as methylthiophene or ethylthiophene. Alkylthiophenes are compounds in which one or more alkyl groups (such as methyl or ethyl) are attached to the thiophene ring, such as 2-methylthiophene or 3-methylthiophene. The introduction of alkyl groups can further modulate the polarity of the reagent and its solubility and dispersion properties in titanium tetrachloride, sometimes resulting in better reaction kinetics.

[0031] According to a second aspect of the present invention, the present invention also provides a method for using a vanadium removal reagent as described in any of the preceding claims for removing vanadium impurities from titanium tetrachloride, wherein the method has mild process conditions and is easy to implement industrially. Please refer to... Figure 1 , Figure 1 The flowchart shown illustrates a method for using a vanadium removal reagent to remove vanadium impurities from titanium tetrachloride, according to an embodiment of the present invention. The method includes: step a) pretreatment by heating the vanadium removal reagent to 70-130°C; step b) mixing the pretreated vanadium removal reagent with titanium tetrachloride containing vanadium oxychloride impurities, and stirring the mixture at 136-140°C for 0.5-4 hours; and step c) distilling the resulting mixture to obtain titanium tetrachloride free of vanadium impurities. This method achieves a highly efficient and safe vanadium removal process through pretreatment, reaction, and distillation steps. Preheating ensures reagent activity, precise control of reaction temperature and time ensures complete reaction, and subsequent distillation achieves efficient product separation.

[0032] In some embodiments, the pretreatment in step a and the reaction step in step b are carried out under an inert gas atmosphere. The use of an inert gas atmosphere prevents reagent oxidation and side reactions, ensuring the stability and safety of the reaction process.

[0033] As a feasible embodiment, step a is a reagent pretreatment step, in which a solid or liquid vanadium removal reagent is placed in a reaction vessel and heated to 70-130°C to melt it or maintain good fluidity. This heating process is preferably carried out under the protection of an inert gas (such as nitrogen or argon) to prevent certain components from being oxidized by oxygen in the air at high temperatures. Step b is a reaction step, in which the preheated vanadium removal reagent is added to crude titanium tetrachloride raw material containing VOCl3 impurities in a certain mass ratio. The reaction temperature is controlled at 136-140°C (close to the boiling point of titanium tetrachloride, 136.4°C), and mechanical stirring at 50-100 r / min is applied to ensure that the two phases are fully mixed and reacted for 0.5-4 hours. Step c is a separation step, in which the mixture is subjected to simple atmospheric distillation after the reaction. Since the boiling point of the vanadium compound complex or decomposition products generated by the reaction is much higher than that of titanium tetrachloride, they can be easily separated by distillation. The fraction collected at 136-140°C is the preliminarily purified titanium tetrachloride.

[0034] In some embodiments, the mass ratio of the pretreated vanadium removal reagent in step b to titanium tetrachloride containing vanadium oxychloride impurities is 1:500 to 1:2000. This ratio range ensures efficient vanadium removal while avoiding excessive waste of reagents and the risk of introducing excessive carbon impurities.

[0035] According to several embodiments of the present invention, the distillation separation in step c is atmospheric distillation, collecting the fraction at 136-140°C. Using atmospheric distillation and controlling the fraction temperature provides a simple and efficient way to separate and purify titanium tetrachloride.

[0036] As a preferred embodiment, to obtain ultra-high purity titanium tetrachloride product to meet the requirements of top-level applications such as aerospace, a precision distillation step can be added after the atmospheric distillation in step c. The crude titanium tetrachloride obtained by atmospheric distillation is sent to a distillation column (e.g., a packed column) for further purification.

[0037] According to several embodiments of the present invention, distillation is carried out in a packed column, the packing in the packed column is stainless steel Pall rings, the top temperature of the column is controlled at 135-137°C, the bottom temperature of the column is controlled at 138-141°C, and the reflux ratio is 4:1 to 12:1.

[0038] In one specific embodiment, the distillation process is carried out in a packed column with a height of 10-15 meters. The column is filled with stainless steel Pall rings (a commonly used, highly efficient structured packing material whose structure provides a large specific surface area, promoting full mass transfer between the gas and liquid phases). The distillation operating parameters are precisely controlled: the top temperature is maintained at 135-137°C, the bottom temperature at 138-141°C, and the reflux ratio (the ratio of reflux flow rate to distillate flow rate) is maintained between 4:1 and 12:1. These stringent process conditions ensure the effective separation of trace light components and heavy impurities with boiling points very close to that of titanium tetrachloride, ultimately yielding an ultra-high purity titanium tetrachloride product with extremely low vanadium and carbon content at the top of the column. For example, in a very specific implementation, the distillation operating parameters can be strictly set as follows: top temperature 136°C, bottom temperature 139°C, and reflux ratio 8:1. Under these conditions, optimal product purity can be obtained.

[0039] In summary, the vanadium removal reagent and its application method disclosed in this application for removing vanadium impurities from titanium tetrachloride achieve highly efficient and deep removal of vanadium impurities through specific component compounding and optimized processes, while simultaneously eliminating the introduction of carbon impurities. The product has extremely high purity, and the process is safe and cost-controllable. This solution overcomes the shortcomings of traditional processes, such as low vanadium removal efficiency, slow rate, use of hazardous reagents, and introduction of secondary carbon pollution. The purity of the obtained titanium tetrachloride product fully meets the stringent application requirements of high-end fields.

[0040] To further understand the method of using the vanadium removal reagent for removing vanadium impurities from titanium tetrachloride provided by the present invention, the following detailed description is provided in specific embodiments.

[0041] Example 1 This embodiment provides a specific application of a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride. The composition of the vanadium removal reagent A, by mass percentage, is: 40% anthracene compounds, 5% phenanthrene compounds, 10% pyrene compounds, 20% thiophene compounds, and 25% naphthalene compounds.

[0042] The raw material titanium tetrachloride contains 0.1% vanadium impurities in the form of vanadium oxychloride (VOCl3) and 0.0012% carbon impurities.

[0043] The specific operating steps are as follows: ① Take 10g of the vanadium removal reagent prepared in the above proportion and place it in a heating container equipped with an inert gas inlet device. Heat it to 90℃ at a heating rate of 5℃ / min and keep it at that temperature for 30min. During this period, nitrogen gas with a purity of ≥99.99% is continuously introduced for protection, and the nitrogen gas flow rate is 0.5L / min.

[0044] ② Add 10 kg of the above-mentioned raw material titanium tetrachloride to a 10 L capacity distillation vessel, turn on the stirring device, adjust the stirring speed to 70 r / min, and at the same time stabilize the temperature inside the vessel at 138℃ by jacket heating.

[0045] ③ The heated vanadium removal reagent, after being kept at a constant temperature, is added to the distillation vessel at a uniform rate using a dropping device. The dropping time is controlled at 15 min. After the dropping is completed, the reaction is continued for 0.5 hours under stirring conditions at 138℃ and 70 r / min.

[0046] ④ After the reaction is complete, turn off the stirring, maintain the temperature inside the vessel at 138℃, and carry out atmospheric distillation. Collect the fraction (titanium tetrachloride) at 136-140℃. The distillation time is 3 hours. The fraction in the first 10 minutes is discarded as the fore-fraction, and 8.5 kg of the middle fraction is collected.

[0047] ⑤ The collected intermediate fraction is fed into a packed column for rectification. The packed column is 12m high and filled with stainless steel Pall ring packing with a specification of Φ25mm. The top temperature of the column is controlled at 136℃ and the bottom temperature at 140℃. The reflux ratio is 7:1 and the rectification time is 5 hours. The top fraction is collected as the final product.

[0048] Test results: Inductively coupled plasma mass spectrometry (ICP-MS) showed that the vanadium impurity content in the final product titanium tetrachloride was 0.0001%, with a vanadium removal rate of 99.9%; high-frequency infrared carbon-sulfur analyzer showed that the carbon impurity content was 0.0004%, a reduction of 66.7% compared to the raw material.

[0049] Example 2 This embodiment provides another specific application of a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride. The composition of the vanadium removal reagent B, by mass percentage, is: 20% anthracene compounds, 10% phenanthrene compounds, 20% pyrene compounds, 30% thiophene compounds, and 20% naphthalene compounds.

[0050] The raw material titanium tetrachloride contains 0.45% vanadium impurities in the form of vanadium oxychloride (VOCl3) and 0.0015% carbon impurities.

[0051] The specific operating steps are as follows: ① Take 12.5g of the vanadium removal reagent prepared in the above proportion and place it in a heating container equipped with an inert gas inlet device. Heat it to 70℃ and keep it at that temperature for 30min. During this period, nitrogen gas with a purity of ≥99.99% is continuously introduced for protection, and the nitrogen gas flow rate is 0.5L / min.

[0052] ② Add 10 kg of the above-mentioned raw material titanium tetrachloride to a 10 L capacity distillation vessel, turn on the stirring device, adjust the stirring speed to 50 r / min, and at the same time stabilize the temperature inside the vessel at 136℃ by jacket heating.

[0053] ③ Add the heated vanadium removal reagent to the distillation vessel using a dropping device. The dropping time is controlled at 20 min. After the dropping is completed, continue the reaction at 136℃ and 50 r / min for 4 hours.

[0054] ④ After the reaction is complete, turn off the stirring, maintain the temperature inside the vessel at 136℃, and carry out atmospheric distillation. Collect the fraction (titanium tetrachloride) at 136-140℃. Discard the fraction in the first 10 minutes as the fore-fraction and collect 8.2 kg of the middle fraction.

[0055] ⑤ The collected intermediate fraction is fed into a packed column for rectification. The packed column is 10m high and filled with stainless steel Pall ring packing with a specification of Φ25mm. The top temperature of the column is controlled at 137℃ and the bottom temperature at 141℃. The reflux ratio is 4:1 and the rectification time is 6 hours. The top fraction is collected as the final product.

[0056] Test results: Inductively coupled plasma mass spectrometry (ICP-MS) showed that the vanadium impurity content in the final product titanium tetrachloride was 0.0005%, with a vanadium removal rate of 99.89%. High-frequency infrared carbon-sulfur analyzer showed that the carbon impurity content was 0.0005%, a reduction of 66.7% compared to the raw material.

[0057] Example 3 This embodiment provides another specific application of a vanadium removal reagent for removing vanadium impurities from titanium tetrachloride. The composition of the vanadium removal reagent C, by mass percentage, is: 60% anthracene compounds, 1% phenanthrene compounds, 5% pyrene compounds, 10% thiophene compounds, and 24% naphthalene compounds.

[0058] The raw material titanium tetrachloride contains 0.03% vanadium impurities in the form of vanadium trichloride (VOCl3) and 0.0010% carbon impurities.

[0059] The specific operating steps are as follows: ① Take 8.3g of the vanadium removal reagent prepared in the above proportion and place it in a heating container equipped with an inert gas inlet device. Heat it to 140℃ and keep it at that temperature for 30min. During this period, nitrogen gas with a purity of ≥99.99% is continuously introduced for protection, and the nitrogen gas flow rate is 0.5L / min.

[0060] ② Add 10 kg of the above-mentioned raw material titanium tetrachloride to a 10 L capacity distillation vessel, turn on the stirring device, adjust the stirring speed to 100 r / min, and at the same time, use the jacket heating to stabilize the temperature inside the vessel at 140℃.

[0061] ③ Add the heated vanadium removal reagent to the distillation vessel using a dropping device. The dropping time is controlled at 10 min. After the dropping is completed, continue to react for 1.5 hours under stirring conditions of 140℃ and 100 r / min.

[0062] ④ After the reaction is complete, turn off the stirring, maintain the temperature inside the vessel at 140℃, and carry out atmospheric distillation. Collect the fraction (titanium tetrachloride) at 136-140℃. Discard the fraction in the first 10 minutes as the fore-fraction and collect 8.7 kg of the middle fraction.

[0063] ⑤ The collected intermediate fraction is fed into a packed column for rectification. The packed column is 15m high and filled with stainless steel Pall ring packing with a specification of Φ25mm. The top temperature of the column is controlled at 135℃ and the bottom temperature at 138℃. The reflux ratio is 12:1 and the rectification time is 4 hours. The top fraction is collected as the final product.

[0064] Test results: Inductively coupled plasma mass spectrometry (ICP-MS) analysis showed that the vanadium impurity content in the final product titanium tetrachloride was 0.0001%, with a vanadium removal rate of 99.67%; high-frequency infrared carbon-sulfur analyzer analysis showed that the carbon impurity content was 0.0003%, a 70% reduction compared to the raw material.

[0065] Example 4 This embodiment provides the application of vanadium removal reagent D, whose composition by mass percentage is: 20% anthracene compounds, 10% phenanthrene compounds, 20% pyrene compounds, 40% thiophene compounds, and 10% naphthalene compounds.

[0066] The raw material titanium tetrachloride contains 0.25% vanadium impurities in the form of vanadium oxychloride (VOCl3) and 0.0018% carbon impurities.

[0067] The specific operating steps are as follows: ① Take 20g of the vanadium removal reagent prepared in the above proportion, place it in a heating container, heat it to 110℃, keep it at that temperature for 30min, and continuously purge nitrogen gas for protection during the process.

[0068] ② Add 10 kg of the above-mentioned raw material titanium tetrachloride to a 10 L capacity distillation vessel, start stirring, adjust the stirring speed to 80 r / min, and at the same time stabilize the temperature inside the vessel at 137℃ by jacket heating.

[0069] ③ The heated vanadium removal reagent after heat preservation is added to the distillation vessel through a dropping device. The dropping time is controlled at 10 min. After the dropping is completed, the reaction is continued at 137℃ and 80 r / min for 1.0 hour.

[0070] ④ After the reaction is complete, perform atmospheric distillation, collect the fraction at 136-140℃, discard the fore fraction, and collect 8.4 kg of the middle fraction.

[0071] ⑤ The collected intermediate fraction is fed into a packed column for rectification. The top temperature of the column is controlled at 136℃ and the bottom temperature at 139℃, with a reflux ratio of 8:1. The top fraction is collected as the final product.

[0072] Test results: The final product, titanium tetrachloride, was found to contain 0.0006% vanadium impurities and 0.0005% carbon impurities.

[0073] Example 5 This embodiment provides the application of vanadium removal reagent E, whose composition by mass percentage is: 50% anthracene compounds, 1% phenanthrene compounds, 5% pyrene compounds, 14% thiophene compounds, and 30% naphthalene compounds.

[0074] The raw material titanium tetrachloride contains 0.08% vanadium impurities in the form of vanadium trichloride (VOCl3) and 0.0009% carbon impurities.

[0075] The specific operating steps are as follows: ① Take 40g of the vanadium removal reagent prepared in the above proportion, heat it to 85℃, keep it at that temperature for 30 minutes, and continuously purge nitrogen gas for protection during the process.

[0076] ② Add 10 kg of the above-mentioned raw material titanium tetrachloride to a 10 L capacity distillation vessel, start stirring, adjust the stirring speed to 90 r / min, and at the same time stabilize the temperature inside the vessel at 139 ℃ by jacket heating.

[0077] ③ Add the heated vanadium removal reagent to the distillation vessel after heat preservation. The addition time is 5 minutes. After the addition is completed, continue to react for 2.5 hours under the conditions of 139℃ and 90r / min stirring.

[0078] ④ After the reaction is complete, perform atmospheric distillation, collect the fraction at 136-140℃, discard the fore fraction, and collect 8.6 kg of the middle fraction.

[0079] ⑤ The collected intermediate fraction is distilled, with the top temperature of the column controlled at 136℃ and the bottom temperature at 140℃, and the reflux ratio at 6:1. The top product is collected.

[0080] Test results: The final product, titanium tetrachloride, was found to contain 0.0002% vanadium impurities and 0.0003% carbon impurities.

[0081] Example 6 The composition of vanadium removal reagent F in this embodiment is the same as that in Example 1 (40% anthracene, 5% phenanthrene, 10% pyrene, 20% thiophene, and 25% naphthalene compounds).

[0082] The raw material titanium tetrachloride contains 0.15% vanadium impurities in the form of vanadium trichloride (VOCl3) and 0.0010% carbon impurities.

[0083] The specific operating steps are as follows: ① Take 5g of the vanadium removal reagent prepared in the above proportion, heat it to 100℃, keep it at that temperature for 30 minutes, and continuously purge nitrogen gas for protection during the process.

[0084] ② Add 10 kg of the above-mentioned raw material titanium tetrachloride to a 10 L capacity distillation vessel, start stirring, adjust the stirring speed to 70 r / min, and at the same time stabilize the temperature inside the vessel at 138℃ by jacket heating.

[0085] ③ Add the heated vanadium removal reagent to the distillation vessel over a 5-minute dropwise period. After the addition is complete, continue the reaction at 138℃ and 70 rpm for 3.5 hours with stirring. (Due to the extremely small amount of reagent used, the reaction time should be appropriately extended to ensure complete reaction.) ④ After the reaction is complete, perform atmospheric distillation, collect the fraction at 136-140℃, discard the fore fraction, and collect 8.5 kg of the middle fraction.

[0086] ⑤ The collected intermediate fraction is distilled, with the top temperature controlled at 136℃ and the bottom temperature at 140℃, and the reflux ratio at 10:1. The top fraction is collected as the final product.

[0087] Test results: The final product, titanium tetrachloride, was found to contain 0.0007% vanadium impurities and 0.0004% carbon impurities.

[0088] As can be seen from Examples 1-6 above, the vanadium impurity content of the final products in all examples was reduced to below 0.0007% (7 ppm), with a minimum of 0.0001% (1 ppm), and the vanadium removal rate reached 99.67% to 99.9%. This indicates that the technical solution of the present invention can stably meet the extremely stringent requirements of high-end applications for vanadium content in titanium tetrachloride to be below 0.0007%. Simultaneously, while efficiently removing vanadium, this technology effectively avoids the introduction of new carbon impurities. The carbon content of the final products is no higher than 0.0005% (5 ppm), and compared to the raw materials, the carbon impurity content is significantly reduced by 66.7% to 70%. This proves that the present invention successfully overcomes the defect of existing technologies that easily introduce secondary pollution and achieves the goal of "low-carbon" purification. In summary, the present invention, through an innovative composite reagent formulation and its supporting process, forms a highly efficient, economical, safe, and stable deep vanadium removal solution for titanium tetrachloride.

[0089] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0090] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A vanadium removal reagent for removing vanadium impurities from titanium tetrachloride, characterized in that, It consists of the following components in the indicated mass percentages: 20-60% anthracene compounds, 1-10% phenanthrene compounds, 5-20% pyrene compounds, 10-30% thiophene compounds, and 10-30% naphthalene compounds, wherein the sum of the mass percentages of the components is 100%, and the vanadium removal reagent is used to react with vanadium oxychloride in titanium tetrachloride to remove vanadium impurities.

2. The vanadium removal reagent for removing vanadium impurities from titanium tetrachloride according to claim 1, characterized in that, The anthracene compound is anthracene, the phenanthrene compound is phenanthrene, the pyrene compound is pyrene, the thiophene compound is thiophene, and the naphthalene compound is naphthalene.

3. The vanadium removal reagent for removing vanadium impurities from titanium tetrachloride according to claim 1, characterized in that, The thiophene compound is an alkylthiophene.

4. The vanadium removal reagent for removing vanadium impurities from titanium tetrachloride according to claim 1, characterized in that, It is composed of the following components in the indicated mass percentages: 40-50% anthracene compounds, 1-5% phenanthrene compounds, 5-10% pyrene compounds, 20-30% thiophene compounds, and 10-25% naphthalene compounds, wherein the sum of the mass percentages of the components is 100%.

5. A method of using the vanadium removal reagent as described in any one of claims 1-4 for removing vanadium impurities from titanium tetrachloride, characterized in that, include: Step a: Pre-treat the vanadium removal reagent by heating it to 70-130℃; Step b: Mix the pretreated vanadium removal reagent with titanium tetrachloride containing vanadium oxychloride impurities, and stir the mixture at 136-140℃ for 0.5-4 hours. Step c: Distill the mixture after the reaction to obtain titanium tetrachloride with vanadium impurities removed.

6. The method of use according to claim 5, characterized in that, The mass ratio of the pretreated vanadium removal reagent in step b to titanium tetrachloride containing vanadium oxychloride impurities is 1:500 to 1:2000.

7. The method of use according to claim 5, characterized in that, The distillation separation in step c is atmospheric distillation, and the fraction collected at 136-140℃ is collected.

8. The method of use according to claim 5, characterized in that, After distillation in step c, the resulting titanium tetrachloride is further subjected to fractional distillation.

9. The method of use according to claim 8, characterized in that, The distillation is carried out in a packed column, the packing of which is stainless steel Pall rings. The top temperature of the column is controlled at 135-137°C, the bottom temperature at 138-141°C, and the reflux ratio is 4:1 to 12:

1.

10. The method of use according to claim 5, characterized in that, The pretreatment in step a and the reaction step in step b are carried out under the protection of an inert gas.

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