C6 compound, application and vanadium removal method

Abstract

The invention discloses a C6 compound, application and a vanadium removal method, the C6 compound is obtained by reacting olefin and TiCl4 at 120-160 DEG C, the volume ratio of the olefin to the TiCl4 is (15-25): (1-5), and the olefin is alpha-olefin or isoprene with the carbon atom number larger than or equal to 9. The C6 compound has a good vanadium removal effect, does not cause the problem of high carbon content impurities in refined TiCl4, does not generate wall-adhered residues to block equipment in a vanadium removal process, is easy to clean, and has a vanadium removal rate of 99.62%; the recycled C6 compound can be reutilized, namely can be used for recycling vanadium-containing compounds, and can also be used for vanadium removal experiments again after being treated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vanadium removal, in particular to a C6 compound, use and method for removing vanadium. BACKGROUND

[0002] Titanium (Ti) and its alloys are widely used in the fields of naval equipment, aerospace, chemical industry and biomedical engineering due to their excellent mechanical properties and good biocompatibility. As the basic raw material for titanium products, the purity of titanium sponge directly affects the performance of the final product. Currently, Kroll method is mainly used in the industrial production of titanium sponge, and the preparation of high-purity titanium tetrachloride (TiCl4) is the key prerequisite for improving the quality of titanium sponge and its downstream products. However, the TiCl4 prepared by the mainstream boiling chlorination method often contains a large amount of metal and non-metal chloride impurities, which usually need to be separated and removed by physical methods such as distillation. Among them, vanadyl trichloride (VOCl3) is difficult to remove effectively by conventional distillation because of its similar boiling point with TiCl4 and easy mutual solubility, so it becomes the core problem restricting the preparation of high-purity TiCl4. Currently, the industrial production of high-purity TiCl4 mainly adopts two processes of aluminum powder method and organic reagent method. The aluminum powder method is widely used due to its good stability and less residue, but its cost is relatively high, and the ultra-fine aluminum powder has an explosion risk, which needs to be handled carefully. In comparison, the organic reagent method has a wide source of raw materials and a lower cost, and has been industrialized in many large titanium enterprises, showing good continuous operation performance and the advantage of simplified process flow. However, not all organic reagents can efficiently remove vanadium. Mineral oil is often selected as a vanadium removal agent in industry, but the compositions of mineral oil from different manufacturers differ greatly, leading to inconsistent reaction performance of VOCl3 and other impurities in crude TiCl4, and the key vanadium removal components are still unclear. In addition, the use of mineral oil can introduce carbon impurities, causing the increase of C content and affecting the quality of titanium sponge. At the same time, the residues produced in the process are easy to adhere to the inner wall of the pipeline, which can cause equipment blockage during long-term operation and need to be cleaned regularly, so the residue adhesion problem also needs to be solved.

[0003] CN118387917A (Kunming University of Science and Technology, publication date 2024.7.26) proposes a new vanadium removal agent HCOOH and H2C2O4, which can be mixed with crude TiCl4 and heated and distilled to obtain fine TiCl4 meeting industrial standards. Although the composition of the vanadium removal agent used is clear and the cost is low, since organic acids are used, oxygen impurities are introduced, which also affects the quality of titanium sponge. Etao et al. of Bohai University used commercial white oil as base oil, added sodium stearate and different contents of aromatic hydrocarbons, characterized the density, flash point, whiteness, kinematic viscosity and components of the mixed oil, and combined with the vanadium removal effect of the mixed oil, a new organic vanadium removal reagent was obtained, which greatly improved the stability of vanadium removal, but still had the problem of introducing carbon impurities, in addition, the residue produced in the vanadium removal process still adhered to the wall.

[0004] Etao et al. of Bohai University directly added high-purity copper powder to the finished mineral oil, utilized the synergistic effect of copper powder and organic matter, efficiently removed VOCl3, improved the residue adhesion problem, and improved the continuous production performance of the process. However, the use of high-purity copper powder also increased the cost, and still increased the carbon impurity content in fine TiCl4. Therefore, it is of great significance to develop a new type of efficient and low-impurity vanadium removal agent to improve the quality and economy of titanium sponge production. SUMMARY

[0005] To solve the above problems, the purpose of the present application is to provide a C6 compound, a use and a vanadium removal method, which has good vanadium removal effect and does not cause high carbon content impurities in fine TiCl4. In the vanadium removal process, no residue is produced to block the equipment, and it is easy to clean. The recovered C6 compound can be reused, i.e. it can be used to recover vanadium-containing compounds, or it can be treated and used again for vanadium removal experiments.

[0006] The present application is realized by the following technical solutions:

[0007] A C6 compound obtained by reacting an olefin and TiCl4 at 120-160℃, the volume ratio of the olefin and TiCl4 being 15-25:1-5, the olefin being an α-olefin with carbon atom number ≥9 or isoprene.

[0008] The α-olefin with carbon atom number ≥9 is at least one of 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-decene or their respective α-olefin homologous isomers.

[0009] The volume ratio of the olefin and TiCl4 is 20:1.

[0010] The use of the C6 compound as described above in vanadium removal.

[0011] A method for vanadium removal involves distilling vanadium-containing crude TiCl4 and the previously described C6 compound. The mass ratio of vanadium-containing crude TiCl4 to C6 compound is 200-300:1. The distillation temperature is 145-160℃. After all TiCl4 has been distilled and cooled to room temperature, ethanol is added. The C6 compound is dispersed in the ethanol. The ethanol and C6 compound are separated by vacuum filtration, followed by washing, drying, and grinding to recover the C6 compound. The recovered C6 compound, when used in vanadium removal experiments on crude TiCl4 under the same conditions, still exhibits good vanadium removal capabilities, maintaining a VOCl3 removal rate of 90.31%. Specifically, this invention prevents wall adhesion: after the purification experiment, ethanol is added to the apparatus, and C6 disperses in the ethanol without wall adhesion. C6 is then separated by vacuum filtration, achieving secondary material recovery.

[0012] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0013] 1. 1-Dodecene is a product of petroleum cracking, which is inexpensive, readily available, and has a simple process for preparing C6 compounds.

[0014] 2. The preparation process is well-defined, and there will be no issues with vanadium removal efficiency due to unknown components.

[0015] 3. While achieving good vanadium removal, it does not cause the problem of high carbon content impurities in refined TiCl4.

[0016] 4. No residue will be produced that sticks to the walls and clogs the equipment during the reaction process, and it is easy to clean.

[0017] 5. The recovered C6 compounds can be reused, either by recovering vanadium-containing compounds or by being processed and reused in vanadium removal experiments. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0019] Figure 1 This refers to the change in VOCl3 content during the refining process of this invention.

[0020] Figure 2 TiCl4 before and after purification of C6 compounds; (a) TiCl4 before purification, (b) TiCl4 after purification.

[0021] Figure 3 The SEM microstructures of the C6 compound are shown in (a) at low magnification and (b) at high magnification.

[0022] Figure 4 The vanadium removal effect diagrams are shown for C6 prepared using different olefins as raw materials in Examples 2-5. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0024] Example 1: The olefin is 1-dodecene.

[0025] Step 1: Preparation of C6

[0026] First, in a 100 ml flask, 1.5 ml of purified TiCl4 was added to 30 ml of 1-dodecene. The mixture was magnetically stirred under vacuum at 80 °C until completely mixed. After purging the solution with N2 for 10 min, the temperature was raised to 150 °C and stirred for 60 min to produce a black solution with a black precipitate. The product was cooled to room temperature and centrifuged at 8000 rpm for 5 min to separate and collect the black precipitate. The precipitate was then washed three times with ethanol and dried under vacuum at 60 °C for 12 h. The dried precipitate was thoroughly ground to obtain vanadium removal agent C6.

[0027] Step 2: Vanadium removal experiment of C6:

[0028] 200 g of crude TiCl4 (VOCl3: 1.1 wt%) and 1 g of the prepared C6 vanadium removal agent were added to a distillation apparatus and distilled at 156 °C for 2 h. Every 30 min, 1 ml of the distilled TiCl4 was taken and 20–30 ml of hydrochloric acid solution (V... 去离子水 / V 浓盐酸 =1 / 1), then dilute to 100 ml with deionized water as the ICP test solution. The purification results are as follows: Figure 1 As shown, the V content decreased from 1.1 wt% to 0.005 wt%, with a removal rate as high as 99.62%. The carbon impurity content in the purified TiCl4 was found to be 15 ppm, which meets the standards for industrial production.

[0029] Step 3: Recycling and reuse of C6:

[0030] After all TiCl4 was distilled and cooled to room temperature, ethanol was added to the distillation apparatus. The C6 compounds were easily dispersed in the ethanol. The mixture was then separated by vacuum filtration, followed by repeated washing, drying, and grinding to recover the C6 compounds. The recovered C6 compounds were used for vanadium removal experiments on crude TiCl4 under the same conditions, still exhibiting good vanadium removal capabilities, with a VOCl3 removal rate remaining at 90.31%.

[0031] Example 2: The olefin is 1-octadecene.

[0032] Step 1: Preparation of C6

[0033] First, in a 100 ml flask, 1 ml of purified TiCl4 was added to 30 ml of 1-octadecene. The mixture was magnetically stirred under vacuum at 80 °C until completely mixed. After purging the solution with N2 for 10 min, the temperature was raised to 150 °C and stirred for 60 min to produce a black solution with a black precipitate. The product was cooled to room temperature and centrifuged at 8000 rpm for 5 min to separate and collect the black precipitate. The precipitate was then washed three times with ethanol and dried under vacuum at 60 °C for 12 h. The dried precipitate was thoroughly ground to obtain vanadium removal agent C6.

[0034] The subsequent steps are the same as in Example 1.

[0035] Example 3: The olefin is 1-decene.

[0036] Step 1: Preparation of C6

[0037] First, in a 100 ml flask, 2.5 ml of purified TiCl4 was added to 30 ml of 1-decene. The mixture was magnetically stirred under vacuum at 80 °C until completely mixed. After purging the solution with N2 for 10 min, the temperature was raised to 150 °C and stirred for 60 min to produce a black solution with a black precipitate. The product was cooled to room temperature and centrifuged at 8000 rpm for 5 min to separate and collect the black precipitate. The precipitate was then washed three times with ethanol and dried under vacuum at 60 °C for 12 h. The dried precipitate was thoroughly ground to obtain vanadium removal agent C6.

[0038] The subsequent steps are the same as in Example 1.

[0039] Example 4: The olefin is isoprene.

[0040] Step 1: Preparation of C6

[0041] First, in a 100 ml flask, 3 ml of purified TiCl4 was added to 30 ml of isoprene. The mixture was magnetically stirred under vacuum at 80 °C until completely mixed. The solution was then purged with N2 for 10 min, heated to 150 °C, and stirred for 60 min to produce a black solution with a black precipitate. The product was cooled to room temperature and centrifuged at 8000 rpm for 5 min to separate and collect the black precipitate. The precipitate was then washed three times with ethanol and dried under vacuum at 60 °C for 12 h. The dried precipitate was thoroughly ground to obtain vanadium removal agent C6.

[0042] The subsequent steps are the same as in Example 1.

[0043] Example 5 1-Hexadecene

[0044] Step 1: Preparation of C6

[0045] First, in a 100 ml flask, 2 ml of purified TiCl4 was added to 30 ml of 1-hexadecene. The mixture was magnetically stirred under vacuum at 80 °C until completely mixed. After purging the solution with N2 for 10 min, the temperature was raised to 150 °C and stirred for 60 min to produce a black solution with a black precipitate. The product was cooled to room temperature and centrifuged at 8000 rpm for 5 min to separate and collect the black precipitate. The precipitate was then washed three times with ethanol and dried under vacuum at 60 °C for 12 h. The dried precipitate was thoroughly ground to obtain vanadium removal agent C6.

[0046] The subsequent steps are the same as in Example 1.

[0047] Example 6 1-Tetradecene

[0048] Similar to Example 5, except that the added olefin is 1-tetradecene.

[0049] Figure 4 The diagrams show the vanadium removal effects of different olefins synthesized into C6 in Examples 2-6. Figure 4 and Figure 1 It can be seen that C6 prepared from α-olefins and isoprene with different numbers of C atoms all exhibit excellent vanadium removal performance, with a VOCl3 removal rate of over 98% in crude TiCl4. The above conclusions further prove the significant beneficial effect of this method.

[0050] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A C6 compound, characterized in that, It is obtained by reacting olefins and TiCl4 at 120-160℃, with a volume ratio of olefin to TiCl4 of 15-25:1-5. The olefin is an α-olefin or isoprene with ≥9 carbon atoms.

2. The C6 compound according to claim 1, characterized in that, The α-olefins with ≥9 carbon atoms are 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-decene, or at least one of their respective α-olefin isomers.

3. The C6 compound according to claim 1, characterized in that, The volume ratio of olefin to TiCl4 is 20:

1.

4. Use of the C6 compound as described in claim 1 or 2 in vanadium removal.

5. A method for removing vanadium, characterized in that, The crude TiCl4 containing vanadium and the C6 compound as described in any one of claims 1-3 are distilled.

6. The method according to claim 4, characterized in that, The mass ratio of crude TiCl4 and C6 compounds containing vanadium is 200-300:

1.

7. The method according to claim 1, characterized in that, The distillation temperature is 145-160℃.

8. The method according to claim 1, characterized in that, After all TiCl4 has been distilled and cooled to room temperature, ethanol is added. The C6 compound is dispersed in the ethanol. The ethanol and C6 compound are separated by vacuum filtration, and the C6 compound is recovered by washing, drying and grinding.

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