Method for removing impurity vanadium in crude titanium tetrachloride

Abstract

The invention discloses a method for removing impurity vanadium in crude titanium tetrachloride, and belongs to the technical field of refined titanium tetrachloride. Nanoscale TiH2 is prepared through an electrochemical method, and the method specifically comprises the steps that hydride of active metal serves as an anode electrode, graphite serves as a cathode electrode, an anion exchange membrane is placed between the cathode and the anode, and an anhydrous organic solvent and chloride of the active metal are added to the anode electrode; the method comprises the following steps: introducing H2 at a cathode electrode, adding TiCl4 and a surfactant, and finally obtaining nanoscale TiH2 on the cathode electrode, and the nanoscale TiH2 prepared by the method has strong reducing ability, so that the nanoscale TiH2 can be used for removing vanadium impurities in crude titanium tetrachloride. The invention provides a novel method for preparing nanoscale TiH2 and removing impurity vanadium in crude titanium tetrachloride.

Description

Technical Field

[0001] The invention relates to a method for removing vanadium as an impurity in crude titanium tetrachloride, belonging to the technical field of refined titanium tetrachloride. Background Art

[0002] Refining titanium tetrachloride is mainly to remove VOCl3 impurities in crude titanium tetrachloride that have a boiling point close to TiCl4. Currently, a variety of chemical methods are used to remove vanadium impurities in crude titanium tetrachloride to reduce the problems of whiteness of titanium dioxide and hardness of sponge titanium caused by residual vanadium impurities in subsequent production.

[0003] Quan Hui et al., whose publication number is CN111087017A, invented a method for removing vanadium from crude titanium tetrachloride. The invention mainly involves mixing catalytic cracking diesel with hydrogen, conducting a hydrogenation reaction in the presence of a hydrogenation catalyst, and separating the reaction effluent to obtain a liquid material; the two streams of crude titanium tetrachloride and the liquid material are contacted in countercurrent in an evaporation tower to carry out a sufficient vanadium removal reaction.

[0004] Zhou Li et al., in publication number CN106241860A, disclosed a method for removing vanadium from crude titanium tetrachloride; the method comprises the steps of first contacting mineral oil with crude titanium tetrachloride and then adding aluminum powder to the liquid phase after solid-liquid separation to remove vanadium.

[0005] E Tao et al., with publication number CN109956498B, disclosed a composite organic material for vanadium removal, including organic base oil, aromatic oil (dimethylaniline), silicone oil (dimethyl silicone oil), graphene (copper-loaded graphene oxide) and metal chloride (zinc chloride).

[0006] Gao Zai et al., with publication number CN114702064A, disclosed a crude titanium tetrachloride vanadium removal reagent, which mainly includes palmitic acid, oleic acid and linoleic acid components, and vanadium is removed by a reasonable ratio of the vanadium removal reagent.

[0007] Although these methods are effective, they usually use the principle of removing vanadium with organic matter, which will inevitably leave residual carbon in the refined titanium tetrachloride, which will eventually be enriched in the titanium sponge and affect the product quality of the titanium sponge. Summary of the invention

[0008] In order to solve the shortcomings of the existing method for removing vanadium from crude titanium tetrachloride, the purpose of the present invention is to provide a method for removing vanadium impurities in crude titanium tetrachloride, the method specifically comprises: placing nano-scale TiH2 in crude titanium tetrachloride, stirring at a constant temperature, reacting at the same constant temperature after the stirring, and performing distillation after the reaction to obtain refined titanium tetrachloride and residue.

[0009] Preferably, the amount of nano-sized TiH2 added to the crude titanium tetrachloride is 1 g / L to 4 g / L.

[0010] Preferably, the constant temperature is 90-130°C.

[0011] Preferably, the reaction time is 1 to 4 hours.

[0012] Preferably, the distillation temperature is 145-160°C.

[0013] Preferably, the preparation method of nano-scale TiH2 is as follows: an active metal hydride is used as an anode electrode, graphite is used as a cathode electrode, the anode electrode and the cathode electrode are separated by an anion exchange membrane, the electrolyte on one side of the anode electrode is composed of an anhydrous organic solvent and a chloride of an active metal, and is heated during electrolysis; the electrolyte on one side of the cathode electrode is composed of TiCl4 and a surfactant, and H2 is introduced at the cathode electrode at the same time, and power is applied to finally obtain nano-scale TiH2 on the cathode electrode.

[0014] Preferably, the amount of the active metal chloride added to the anhydrous organic solvent is 0.02-0.05 g / mL.

[0015] Preferably, the anhydrous organic solvent is one of tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetonitrile (CH3CN), glycerol (C3H8O3) or acetone (CH3COCH3).

[0016] Preferably, the active metal is one of Li, Na, Fe or Al.

[0017] Preferably, the heating temperature is 50-100°C.

[0018] Preferably, the volume ratio of TiCl4 to surfactant is (50-200):(2-5).

[0019] Preferably, the surfactant is one of cetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), formamide, rhamnolipid (Rha) or lignin sulfonate dispersant.

[0020] Beneficial effects of the present invention

[0021] (1) The nano-sized TiH2 prepared by the method of the present invention has a small particle size and can fully react with crude titanium tetrachloride. In addition, the H in TiH2 has a strong reducing ability and can effectively reduce VOCl3, thereby removing vanadium impurities without introducing an additional carbon source, directly avoiding the problem of carbon residue in refined titanium tetrachloride from the source, and improving the purity of titanium tetrachloride. This is a more ideal method for removing vanadium.

[0022] (2) Compared with the organic vanadium removal method, the vanadium removal method using TiH2 does not produce difficult-to-treat organic residues and is more environmentally friendly and efficient.

[0023] (3) In the process of vanadium removal, the Ti element in TiH2 can be reasonably utilized to achieve the recovery of titanium tetrachloride, which not only improves the utilization rate of raw materials but also reduces production costs.

[0024] (4) Compared with the four commonly used chemical methods for vanadium removal (aluminum powder vanadium removal, hydrogen sulfide vanadium removal, copper wire vanadium removal, and organic matter vanadium removal), the nano-scale TiH2 used in the present invention has the advantages of being non-flammable, non-corrosive to equipment, and easy to recycle titanium tetrachloride. Both the Ti and H elements of TiH2 can be utilized, which is suitable for purifying crude titanium tetrachloride containing high vanadium. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a process diagram for the electrochemical preparation of nano-sized TiH2 according to the present invention.

[0026] Figure 2 The figure is a simplified flow chart of the method for removing vanadium from crude titanium tetrachloride using nano-sized TiH2 of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0028] The chemical reactions involved in the embodiments are as follows:

[0029] Chemical reactions involved in the electrochemical preparation of nano-sized TiH2:

[0030] The overall reaction is 4MeH+TiCl4=4MeCl+TiH2+H2↑ or 2MeH2+TiCl4=2MeCl+TiH2+H2↑ (Me refers to the active metal)

[0031] Anode reaction formula: 4MeH+4Cl - -4e - =4MeCl+2H2↑; 2MeH2+4Cl - -4e - =2MeCl2+2H2↑, etc.

[0032] Cathode reaction formula: TiCl4+H2+4e - =TiH2+4Cl - ;

[0033] The chemical reactions involved in the process of removing vanadium using nano-scale TiH2 are as follows:

[0034] The main reaction is as follows:

[0035] VOCl3+TiH2+3TiCl4→VCl3↓+4TiCl3↓+H2O

[0036] VOCl3+TiH2+2TiCl4→VOCl2↓+3TiCl3↓+H2↑

[0037] 3VOCl3+TiH2→3VOCl2↓+TiCl3↓+H2↑

[0038] The side effects are as follows:

[0039] VOCl3+TiCl3→VOCl2↓+TiCl4

[0040] 2VOCl3+H2(g)→2VOCl2↓+2HCl↑

[0041] VOCl3+H2(g)→VCl3↓+H2O↑

[0042] TiCl4+2H2O→TiO2↓+4HCl

[0043] Example 1

[0044] A method for removing vanadium impurities in crude titanium tetrachloride, the specific steps are as follows:

[0045] (1) Nano-sized TiH2 was prepared by electrochemical method: the anode electrode was an active metal hydride NaH with a mass of 45 g. 50 mL of dimethyl sulfoxide (DMSO) organic solvent and 2 g of NaCl were added to the anode electrode and heated to 100 °C during electrolysis. The cathode electrode was a graphite electrode. H2 was passed into the electrode and 50 mL of TiCl4 and 2 mL of surfactant hexadecyltrimethylammonium bromide (CTAB) were added. An anion exchange membrane was placed in the middle. Finally, nano-sized TiH2 was obtained on the cathode electrode.

[0046] (2) Weigh 0.1 g of nano-sized TiH2 and place it in 100 mL of crude titanium tetrachloride. The composition of the crude titanium tetrachloride is shown in Table 1.

[0047] (3) Heat the device containing TiH2 and crude titanium tetrachloride to 110°C, stir evenly and allow to react for 2 hours.

[0048] (4) After the reaction is completed, the temperature is raised to 150° C. for distillation to separate the refined titanium tetrachloride and the residue.

[0049] The particle size distribution of TiH2 prepared in this embodiment is 60-130nm. The refined titanium tetrachloride obtained in this embodiment is subjected to ICP detection of V element content. The detection results are shown in Table 1. It can be seen from Table 1 that the V element is 1.0065ppm and the purity of refined titanium tetrachloride is 99.91%.

[0050] Example 2

[0051] A method for removing vanadium impurities in crude titanium tetrachloride, the specific steps are as follows:

[0052] (1) Nano-sized TiH2 was prepared by electrochemical method: the anode electrode was an active metal hydride MgH2 with a mass of 70 g. 150 mL of acetonitrile (CH3CN) organic solvent and 5 g of FeCl3 were added to the anode electrode and heated to 80°C during electrolysis. The cathode electrode was a graphite electrode. H2 was passed into the electrode and 150 mL of TiCl4 and 3 mL of surfactant polyethylene glycol (PEG) were added. An anion exchange membrane was placed in the middle. Finally, nano-sized TiH2 was obtained on the cathode electrode.

[0053] (2) Weigh 0.2 g of nano-sized TiH2 and place it in 100 mL of crude titanium tetrachloride. The composition of the crude titanium tetrachloride is shown in Table 1.

[0054] (3) The temperature of the device containing TiH2 and crude titanium tetrachloride was raised to 90°C, and the mixture was stirred evenly and allowed to react for 4 hours.

[0055] (4) After the reaction is completed, the temperature is raised to 145°C for distillation to separate the refined titanium tetrachloride and the residue.

[0056] The particle size distribution of TiH2 prepared in this embodiment is 76-150nm. The refined titanium tetrachloride obtained in this embodiment is subjected to ICP detection of V element content. The detection results are shown in Table 1. It can be seen from Table 1 that the V element is 1.4896ppm and the refined titanium tetrachloride is 99.94%.

[0057] Example 3

[0058] A method for removing vanadium impurities in crude titanium tetrachloride, comprising the steps of:

[0059] (1) Nano-sized TiH2 was prepared by electrochemical method: the anode electrode was an active metal hydride LiH with a mass of 60 g. 200 mL of anhydrous tetrahydrofuran (THF) organic solvent and 10 g of LiCl were added to the anode electrode and heated to 50°C during electrolysis. The cathode electrode was a graphite electrode. H2 was passed into the electrode and 200 mL of TiCl4 and 2 mL of surfactant hexadecyltrimethylammonium bromide (CTAB) were added. An anion exchange membrane was placed in the middle. Finally, nano-sized TiH2 was obtained on the cathode electrode.

[0060] (2) Weigh 0.4 g of nano-sized TiH2 and place it in 100 mL of crude titanium tetrachloride. The composition of the crude titanium tetrachloride is shown in Table 1.

[0061] (3) Heat the device containing TiH2 and crude titanium tetrachloride to 130°C, stir evenly and allow to react for 1 hour.

[0062] (4) After the reaction is completed, the temperature is raised to 160°C for distillation to separate the refined titanium tetrachloride and the residue.

[0063] The particle size distribution of TiH2 prepared in this embodiment is 70-155nm. The refined titanium tetrachloride obtained in this embodiment is subjected to ICP detection of V element content. The detection results are shown in Table 1. It can be seen from Table 1 that the V element is 0.9382ppm and the refined titanium tetrachloride is 99.95%.

[0064] Table 1 Evaluation of the reaction effect of crude titanium tetrachloride and TiH2

[0065]

[0066] In the present invention, the crude titanium tetrachloride includes the following components: TiCl4 99.4-99.68wt%, AlCl3 0.08-0.12wt%, FeCl3 0.1-0.15wt%, VOCl3 0.14-0.33wt%, which can be determined according to different crude titanium tetrachloride components. It should be understood that crude titanium tetrachloride is crude titanium tetrachloride obtained by reacting rutile or high-titanium slag with chlorine and then settling to remove solid matter, which includes not only VOCl3, TiCl4, FeCl3, AlCl3, but also impurity compounds that may exist in crude titanium tetrachloride such as SiCl4 and are insoluble in TiCl4.

[0067] Through the above examples, it is known that the use of the vanadium removal reagent nano-scale TiH2 of the present invention can realize the cyclic devanadium reaction of titanium tetrachloride, and can reduce the carbon source from the root of the vanadium removal reagent. Compared with aluminum powder vanadium removal, hydrogen sulfide vanadium removal, copper wire vanadium removal, and organic matter vanadium removal, the nano-scale TiH2 used in the present invention has the advantages of being non-flammable, non-corrosive to equipment, easy to recover titanium tetrachloride, and less residue. The Ti and H elements of TiH2 can be used, which is suitable for purifying crude titanium tetrachloride containing high vanadium. The present invention discloses a highly efficient vanadium removal method for crude titanium tetrachloride using nano-scale TiH2, which provides a more ideal and efficient vanadium removal method.

[0068] So far, the present invention has described the technical solutions of the present invention in detail through embodiments. However, for professionals in the field, the protection scope of the present invention is not limited to these specific embodiments. Without departing from the principles of the present invention, professionals can make equivalent adjustments or substitutions to the technical features of the present invention, but all these adjusted or substituted technical solutions will be considered to belong to the protection scope of the present invention.

Claims

1. A method for removing vanadium impurities in crude titanium tetrachloride, characterized in that: Nano-sized TiH2 is placed in crude titanium tetrachloride and stirred at a constant temperature. After the stirring, the mixture is reacted at the same constant temperature. After the reaction, the mixture is rectified to obtain refined titanium tetrachloride and residue.

2. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 1, characterized in that: The amount of nano-TiH2 added to the crude titanium tetrachloride is 1 g / L to 4 g / L.

3. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 1, characterized in that: The constant temperature is 90~130℃.

4. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 1, characterized in that: The reaction time is 1 to 4 hours.

5. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 1, characterized in that: The distillation temperature is 145-160°C.

6. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 1, characterized in that: The preparation method of nano-scale TiH2 is as follows: an active metal hydride is used as an anode electrode, graphite is used as a cathode electrode, the anode electrode and the cathode electrode are separated by an anion exchange membrane, the electrolyte on one side of the anode electrode is composed of an anhydrous organic solvent and a chloride of an active metal, and is heated during electrolysis; the electrolyte on the cathode electrode side is composed of TiCl4 and a surfactant, and H2 is introduced into the cathode electrode at the same time, and power is applied to finally obtain nano-scale TiH2 on the cathode electrode.

7. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 6, characterized in that: The amount of active metal chloride added to the anhydrous organic solvent is 0.02-0.05 g / mL.

8. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 6, characterized in that: The heating temperature is 50-100°C.

9. The method for removing vanadium impurities from crude titanium tetrachloride according to claim 6, characterized in that: The volume ratio of TiCl4 and surfactant is (50-200):(2-5).

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