Ultrahigh-purity titanium tetrachloride production method and device

Abstract

The invention relates to an ultra-pure titanium tetrachloride production method and device, and the method comprises the steps: sequentially carrying out catalytic reaction adsorption separation on a titanium tetrachloride raw material to remove metal vanadium, carrying out microfiltration to preliminarily remove particle impurities, carrying out rectification separation to remove organic impurities and water, and carrying out nanofiltration to further remove particle impurities to obtain ultra-pure titanium tetrachloride. Compared with the prior art, the method and the device for producing the high-purity and high-purity titanium tetrachloride by using the industrial-grade titanium tetrachloride are efficient, stable and energy-saving, and have the advantages of short flow, low energy consumption, good separation effect, strong process continuity, high purity, low impurity content and the like, and the produced ultra-pure titanium tetrachloride can meet the production requirements of chips of more than 12 inches.

Description

Technical Field

[0001] The present invention belongs to the technical field of separation and purification, and relates to a method and device for producing titanium tetrachloride. Background Art

[0002] Titanium tetrachloride is an important intermediate raw material for preparing precursors in the fields of optoelectronics, semiconductors, and aerospace. Impurities in titanium tetrachloride have an important impact on the quality of the precursor. At present, in the quality standard of refined titanium tetrachloride in Japan, the main detections are the contents of titanium tetrachloride TiCl 4 , silicon tetrachloride SiCl 4 , vanadyl trichloride VOCl 3 , ferric chloride FeCl 3 content and chromaticity. The United States has added free chlorine and the contents of copper Cu, tin Sn, antimony Sb, nickel Ni, arsenic As, and lead Pb to the Japanese standard, mainly with high requirements for metal content. In the Chinese standard of refined titanium tetrachloride, it is similar to the Japanese standard, only having requirements for the contents of titanium tetrachloride TiCl 4 , silicon tetrachloride SiCl 4 , vanadyl trichloride VOCl 3 , ferric chloride FeCl 3 content and chromaticity, and having no requirements for the contents of metal ions and organic substances, which cannot meet the requirements of high-end manufacturing industries such as aerospace and semiconductors for titanium tetrachloride.

[0003] Ultra-high purity titanium tetrachloride is usually purified from industrial-grade titanium tetrachloride. The difficulty lies in removing metal impurities such as vanadium and particles at low cost. Chinese Patent Application CN201410075517.7 proposes using magnesium hydride as a vanadium remover to remove vanadium. However, magnesium hydride is a strong reducing agent with high chemical reactivity, and it reacts violently with water or acid, which can cause combustion, is unsafe to operate, and has a high cost; Chinese Patent Applications CN201910731322.6, CN201910731756.6, and CN201922206634.3 propose obtaining ultra-high purity titanium tetrachloride by rectification and purification. Specific product indicators are not described, and only removing vanadium to the ppb level by rectification has extremely high energy consumption; Chinese Patent Application CN 201810120467.8 uses aluminum and aluminum trichloride as vanadium removers to remove vanadium, a microporous filter, sub-boiling rectification, and finally obtains ultra-high purity titanium tetrachloride by rectification. Sub-boiling rectification is not suitable for industrialization; Chinese Patent Applications CN201910352302.8, CN202111311408.7, and CN202111060165.4 use a combination of organic substances to remove vanadium and rectification to obtain ultra-high purity titanium tetrachloride, which introduces organic impurities and cannot remove vanadium to the ppb level. Summary of the Invention

[0004] The object of the present invention is to provide a method and device for efficiently, stably and energy-savingly producing high-purity and high-purity titanium tetrachloride from industrial-grade titanium tetrachloride.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] In a first aspect of the present invention, a method for producing ultra-high-purity titanium tetrachloride is provided, including: subjecting a titanium tetrachloride raw material to catalytic reaction adsorption separation in sequence to remove metallic vanadium, microfiltration to preliminarily remove particulate impurities, rectification separation to remove organic impurities and water, and nanofiltration to further remove particulate impurities, so as to obtain ultra-high-purity titanium tetrachloride.

[0007] Further, in the catalytic reaction adsorption separation process, the adsorbent used is a zeolite molecular sieve loaded with copper and / or aluminum;

[0008] When loaded with copper, the copper loading is 3-8 wt%; when loaded with aluminum, the aluminum loading is 2-4 wt%;

[0009] When loaded with copper and aluminum, the mass ratio of copper to aluminum is 2-3:1.

[0010] Further, in the microfiltration process, the filtration pore size of the microfilter used is 0.1-0.5 μm (micrometer).

[0011] Further, in the microfiltration process, the filter membrane used is one of a polytetrafluoroethylene membrane, a polyethersulfone membrane, a polyvinylidene fluoride membrane (PVDF), a polyimide membrane or a polyamide membrane.

[0012] Further, the rectification separation process is achieved by a single rectification column or at least 2 rectification columns arranged in series.

[0013] Further, the theoretical number of plates of the rectification column is 50-100, the top temperature is 140-150 °C, and the reflux ratio is 3-20. The operating pressure is preferably atmospheric pressure or slightly positive pressure.

[0014] Further, the rectification column is a dividing wall column.

[0015] Further, the form of the dividing wall column is one of an intermediate dividing wall, an upper dividing wall or a lower dividing wall; the theoretical number of plates is 100-150, the top temperature is 140-150 °C, and the reflux ratio is 6-18. The operating pressure is preferably atmospheric pressure or slightly positive pressure.

[0016] Further, the area ratio of the feed side to the product withdrawal side in the dividing wall column is 1:4-4:1.

[0017] Further, in the nanofiltration process, the pore size of the filter membrane used is 10-50 nm (nanometer).

[0018] The second aspect of the present invention provides an ultra-high purity titanium tetrachloride production device, including those connected in sequence

[0019] A catalytic reaction adsorption separation device, used to successively carry out catalytic reaction adsorption separation on titanium tetrachloride raw materials to remove metallic vanadium;

[0020] A microfilter, used to preliminarily remove particulate impurities;

[0021] A separator, used to remove organic impurities and water by rectification;

[0022] A nanofiltration device, used to further remove particulate impurities.

[0023] Furthermore, it includes those connected in sequence

[0024] An anhydrous and oxygen-free feeding system. Since titanium tetrachloride reacts with water, in order to prevent unnecessary reactions of industrial-grade titanium tetrachloride from outside the battery limit during the feeding process, an anhydrous and oxygen-free feeding environment needs to be provided;

[0025] A catalytic reaction adsorption separation device, used to remove vanadium from the titanium tetrachloride in the anhydrous and oxygen-free feeding system. Zeolite molecular sieves loaded with metallic copper and metallic aluminum are filled inside this device;

[0026] A microfilter. The titanium tetrachloride from the catalytic reaction adsorption separation device enters the microfilter to remove particles preferably with a size of more than 0.2 μm;

[0027] A separator. The titanium tetrachloride after removing large particles enters the separator to remove organic impurities and water. According to actual raw materials and product standard requirements, the number of separators can be increased by 1 - 2. The present invention can use a traditional rectification column or a dividing wall rectification column. Under the condition of meeting the same separation accuracy requirements, the dividing wall rectification column can reduce the number of conventional rectification columns. Two original conventional rectification columns are reduced to one, greatly reducing energy consumption and investment; among them, both the traditional rectification column and the dividing wall rectification column preferably include a condenser and a reboiler;

[0028] A nanofiltration device. The product titanium tetrachloride obtained by rectification preferably filters out particles with a size of more than 10 nm through the nanofiltration device;

[0029] An anhydrous and oxygen-free feeding system. The titanium tetrachloride obtained by nanofiltration enters the anhydrous and oxygen-free canning system to obtain titanium tetrachloride products.

[0030] The present invention feeds industrial-grade titanium tetrachloride raw materials (titanium tetrachloride mass content above 99%) into the catalytic reaction adsorption separation device to remove vanadium, enters the microfilter to remove large particles in the titanium tetrachloride and then enters the separator. The separator uses a conventional rectification column or a dividing wall column. The dividing wall column can halve the number of conventional rectification columns, reduce equipment, lower energy consumption, and shorten the process; the titanium tetrachloride distilled out from the separator enters the nanofiltration device to remove fine particles to obtain products.

[0031] Compared with the prior art, the present invention has the following characteristics:

[0032] 1) The present invention can use a traditional distillation column or a dividing wall distillation column. Under the condition of meeting the same separation accuracy requirements, the dividing wall distillation column can reduce the number of conventional distillation columns. The original two conventional distillation columns are reduced to one, greatly reducing energy consumption and investment.

[0033] 2) The present invention provides a method and device for efficiently, stably and energy-savingly producing high-purity and high-purity titanium tetrachloride from industrial-grade titanium tetrachloride, and has the advantages of short process, low energy consumption, good separation effect, strong process continuity, high purity, low impurity content, etc. The ultra-high-purity titanium tetrachloride produced can meet the production requirements of chips above 12 inches. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of a production process device for ultra-high-purity titanium tetrachloride in Example 1;

[0035] Figure 2 is a schematic diagram of a production process device for ultra-high-purity titanium tetrachloride in Example 2;

[0036] Figure 3 is a schematic diagram of a production process device for ultra-high-purity titanium tetrachloride in Comparative Example 1;

[0037] Figure 4 is a schematic diagram of a production process device for ultra-high-purity titanium tetrachloride in Comparative Example 2;

[0038] Figure 5 is a schematic diagram of three types of dividing wall columns;

[0040] 1 - Anhydrous and oxygen-free feeding system; 2 - Industrial-grade titanium tetrachloride; 3 - Catalytic reaction adsorption separation device; 4 - Titanium tetrachloride after vanadium removal; 5 - Microfilter; 6 - Titanium tetrachloride after microfiltration; 7 - First separator; 8 - Light components; 9 - Titanium tetrachloride after light component removal; 10 - Second separator; 11 - Titanium tetrachloride after rectification; 12 - Heavy components; 13 - Nanofiltration membrane; 14 - Titanium tetrachloride after nanofiltration; 15 - Anhydrous and oxygen-free canning system; 16 - Single separator. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manner and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0042] As Figure 1As shown in the figure, a production process device for ultra-high purity titanium tetrachloride mainly includes an anhydrous and oxygen-free feeding system 1, a catalytic reaction adsorption separation device 3, a microfilter 5, a separator, a nanofiltration device 13, an anhydrous and oxygen-free canning system 15, and auxiliary equipment such as corresponding pumps and heat exchangers (since auxiliary equipment such as pumps and heat exchangers will not have a substantial impact on the invention, they are not mentioned in the present invention, especially in the embodiments). The present invention provides a production method and device for ultra-high purity titanium tetrachloride with a short process, low energy consumption, good separation effect, strong process continuity, high purity, and low impurity content, obtaining a product with a purity meeting the requirements of more than 99.9999% wt and metal ions below 100 ppt. Ultra-high purity titanium tetrachloride meeting the requirements of industries such as aerospace and semiconductors.

[0043] The process flow is as follows: Industrial-grade titanium tetrachloride 2 from the anhydrous and oxygen-free feeding system 1 enters the catalytic reaction adsorption separation device 3 to remove metallic vanadium, obtaining titanium tetrachloride 4 after vanadium removal; then it enters the microfilter 5 to remove particles with a size of more than 0.2 μm, obtaining microfiltered titanium tetrachloride 6. The microfilter 5 can use a polytetrafluoroethylene membrane, a polyethersulfone membrane, a polyvinylidene fluoride membrane, a polyimide membrane, a polyamide membrane, or other membranes with the same properties with a pore size of 0.1 - 0.5 μm; after microfiltration, it enters a single separator 16 or a first separator 7 and a second separator 10 arranged in series to remove light and heavy component impurities, removing light components 8 and heavy components 12, obtaining rectified titanium tetrachloride 11. The separator in the present invention uses a conventional distillation column or a dividing wall distillation column. Under the condition of meeting the same separation accuracy requirements, the dividing wall column can significantly reduce the number of conventional distillation columns, reducing the original 2 distillation columns to 1, significantly reducing energy consumption and investment. The area ratio range on both sides of the dividing wall distillation column is 2:8 to 8:2, and the forms mainly include middle dividing wall, upper dividing wall, and lower dividing wall (as Figure 5 shown). The present invention preferably adopts the middle dividing wall type. The titanium tetrachloride 11 obtained from the separator is filtered by the nanofiltration device 13 to remove particles larger than 10 nm, obtaining nanofiltrated titanium tetrachloride 14. The filter membrane in the nanofiltration device 13 can use a polytetrafluoroethylene membrane, a polyethersulfone membrane, a polyvinylidene fluoride membrane, a polyimide membrane, a polyamide membrane, or other membranes with the same properties with a pore size of 10 - 50 nm. After nanofiltration, it enters the anhydrous and oxygen-free canning system 15 to obtain an ultra-high purity titanium tetrachloride product with a purity of more than 99.9999% wt and each metal content below 100 ppt.

[0044] The titanium tetrachloride raw material in the present invention is industrial-grade titanium tetrachloride. The national standard for industrial-grade titanium tetrachloride has a purity of more than 99% by mass, a mass content of silicon tetrachloride below 0.03%, a mass content of vanadyl trichloride below 0.0024%, a mass content of ferric trichloride below 0.003%, and a mass content of other impurities below 0.0446%. The specific raw material indicators are shown in Table 1 below.

[0045] Table 1 Raw material titanium tetrachloride indicators

[0046]

[0047] Example 1:

[0048] As Figure 1 shown, industrial-grade titanium tetrachloride 2 from the anhydrous and oxygen-free feeding system 1 enters the catalytic reaction adsorption separation device 3 to remove metallic vanadium. The catalytic adsorption separation device 3 is a fixed-bed reactor, and the catalyst is the ZSM-5 zeolite molecular sieve of Nankai University loaded with metallic copper and metallic aluminum, wherein the loading amount of metallic copper is 5 wt%, the loading amount of metallic aluminum is 3 wt%, and the copper loading amount / aluminum loading amount (weight ratio) is 2.5:1. The catalytic reaction conditions are 130 °C and the pressure is atmospheric pressure; then it enters the microfilter 5 to remove particles larger than 0.2 μm. The filter membrane in the microfilter 5 can adopt a polytetrafluoroethylene membrane with a pore size of 0.2 μm and a uniformity coefficient of 1.1; after microfiltration, it enters the dividing-wall distillation column 16, adopting the A type, with the area ratio of both sides being 5:5, the top pressure of the column being 0.121 MPa, the top temperature of the column being 144 °C, the bottom temperature of the column being 151 °C, the number of theoretical plates being 100, and the reflux ratio being 8 to remove light and heavy component impurities. The titanium tetrachloride 11 obtained from the dividing-wall distillation column 16 is filtered by the nanofiltration device 13 to remove particles larger than 10 nm. The filter membrane in the nanofiltration device 13 can adopt a polyvinylidene fluoride membrane with a pore size of 10 nm and a uniformity coefficient of 1.25. After nanofiltration, it enters the anhydrous and oxygen-free canning system 15 to obtain an ultra-high purity titanium tetrachloride product, and the product indexes are shown in Table 2.

[0049] Example 2:

[0050] As Figure 2As shown, industrial-grade titanium tetrachloride 2 from the anhydrous and oxygen-free feeding system 1 enters the catalytic reaction adsorption separation device 3 to remove metallic vanadium. The catalytic adsorption separation device is a fixed-bed reactor. The catalyst (same as in Example 1) is zeolite molecular sieve loaded with metallic copper and metallic aluminum, where the loading amount of metallic copper is 5%, the loading amount of metallic aluminum is 3%, and the ratio of copper loading amount to aluminum loading amount (by weight) is 2.5:1. Then it enters the microfilter 5 to remove particles larger than 0.2 μm. The microfilter 5 can use a polytetrafluoroethylene membrane with a pore size of 0.2 μm and a uniformity coefficient of 1.1. After microfiltration, it enters the separator. The separator uses a first separator 7 and a second separator 10 arranged in series, that is, two conventional distillation columns. The top pressure of the first separator 7 is 0.121 kPa, the top temperature is 144.3 °C, the bottom temperature is 145 °C, the number of theoretical plates is 50, the reflux ratio is 12, and the bottom discharges. The top pressure of the second separator 10 is 0.126 MPa, the top temperature is 144.7 °C, the bottom temperature is 151.4 °C, the number of theoretical plates is 50, the reflux ratio is 3, to remove light and heavy component impurities. The titanium tetrachloride 11 obtained from the distillation column 10 filters out particles through the nanofiltration device 13. The filter membrane of the nanofiltration device 13 can use a polytetrafluoroethylene membrane with a pore size of 20 nm and a uniformity coefficient of 1.15. After nanofiltration, it enters the anhydrous and oxygen-free canning system 15. Other conditions are the same as in Example 1 to obtain an ultra-high purity titanium tetrachloride product. The product indexes are shown in Table 2.

[0051] Comparative Example 1:

[0052] Reference Figure 3 , compared with Example 1, the catalytic adsorption reaction device 3 for vanadium removal is not set, and others are the same as in Example 1. The product indexes are shown in Table 2. The vanadium content seriously exceeds the standard.

[0053] Comparative Example 2:

[0054] Reference Figure 4 , compared with Example 2, the nanofiltration device 13 is not set, and others are the same as in Example 2. The product indexes are shown in Table 2. The particles seriously exceed the standard, and iron and calcium also exceed the standard.

[0055] Test Example 1

[0056] The components in the titanium tetrachloride of Examples 1-2 and Comparative Examples 1-2 were detected for content. The detection instruments were: for raw material metal elements and elements such as boron, silicon, and arsenic, PerkinElmer ICP-OES / Avio550MAX was used; for product metal elements and elements such as boron, silicon, and arsenic, Agilent ICP-MS / MS 8900 was used; for raw material and product impurity content, Agilent GC-MS gas chromatography was used; and for particle size analyzer, RION-KS-19AF was used. The results are shown in Tables 1-2.

[0057] Table 2 Product indexes obtained after treatment by the present invention

[0058]

[0059]

[0060]

[0061] The above table is for illustrating the components contained in the titanium tetrachloride raw material, without limiting the applicability of the invention. The mass content of the titanium tetrachloride product produced by the method of the present invention can reach more than 99.9999%, the metal content is below 100 ppt, the silicon content and arsenic content are below 100 ppt, and the boron content is below 300 ppt, meeting the requirements for titanium tetrachloride in the semiconductor process below 14 nm.

[0062] The above description of the embodiments is for facilitating those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A method for producing ultra-high purity titanium tetrachloride, characterized in that, the method comprises: subjecting the titanium tetrachloride raw material to catalytic reaction adsorption separation in sequence to remove metallic vanadium, microfiltration to preliminarily remove particulate impurities, rectification separation to remove organic impurities and water, and nanofiltration to further remove particulate impurities, thereby obtaining ultra-high purity titanium tetrachloride.

2. The method for producing ultra-high purity titanium tetrachloride according to claim 1, characterized in that, during the catalytic reaction adsorption separation process, the adsorbent used is a zeolite molecular sieve loaded with copper and / or aluminum; when loaded with copper, the copper loading is 3-8 wt%; when loaded with aluminum, the aluminum loading is 2-4 wt%; when loaded with copper and aluminum, the mass ratio of copper to aluminum is 2-3:

1.

3. The method for producing ultra-high purity titanium tetrachloride according to claim 1, characterized in that, during the microfiltration process, the filtration pore size of the microfilter used is 0.1-0.5 μm.

4. The method for producing ultra-high purity titanium tetrachloride according to claim 1, characterized in that, during the microfiltration process, the filter membrane used is one of polytetrafluoroethylene membrane, polyethersulfone membrane, polyvinylidene fluoride membrane, polyimide membrane or polyamide membrane.

5. The method for producing ultra-high purity titanium tetrachloride according to claim 1, characterized in that, the rectification separation process is realized by a single rectification column or at least 2 rectification columns arranged in series.

6. The method for producing ultra-high purity titanium tetrachloride according to claim 5, characterized in that, the theoretical number of plates of the rectification column is 50-100, the top temperature is 140-150 °C, and the reflux ratio is 3-20.

7. The method for producing ultra-high purity titanium tetrachloride according to claim 5, characterized in that, the rectification column is a dividing wall column.

8. The method for producing ultra-high purity titanium tetrachloride according to claim 7, characterized in that, the theoretical number of plates of the dividing wall column is 100-150, the top temperature is 140-150 °C, the reflux ratio is 6-18, and the area ratio of the feed side to the product withdrawal side is 1:4-4:

1.

9. The method for producing ultra-high purity titanium tetrachloride according to claim 1, characterized in that, during the nanofiltration process, the pore size of the filter membrane used is 10-50 nm.

10. An ultra-high purity titanium tetrachloride production device, characterized in that, comprising sequentially connected a catalytic reaction adsorption separation device for subjecting the titanium tetrachloride raw material to catalytic reaction adsorption separation to remove metallic vanadium; a microfilter for preliminarily removing particulate impurities; a separator for rectification to remove organic impurities and water; a nanofiltration device for further removing particulate impurities.

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