Production method of special high-oxygen-content titanium tetrachloride product for smelting titanium alloy

Abstract

The invention belongs to the field of titanium chemical industry, and particularly relates to a production method of special high-oxygen-content titanium tetrachloride for smelting titanium alloy, which comprises the following steps: a raw material preparation procedure: pretreating titanium slag and petroleum coke to ensure that the proportion of the titanium slag with the particle size of less than 0.1 mm is greater than 90% and the proportion of the petroleum coke with the particle size of less than 0.15 mm is greater than 90%; and a chlorination process: adding the pretreated titanium slag, petroleum coke and a fused salt medium into a fused salt chlorination furnace, heating to 850-900 DEG C, and introducing chlorine to carry out chlorination reaction to generate a titanium tetrachloride product with high oxygen content. According to the method, the high-oxygen-content titanium tetrachloride product is produced by controlling the granularity and purity of the raw materials and chlorination reaction conditions, so that component elements in titanium tetrachloride are uniform from the source, and the quality of a titanium material is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metallurgy, and more specifically, relates to a production method of a titanium tetrachloride product with a high oxygen content specially used for smelting titanium alloy. Background Art

[0002] Sponge titanium is the main material for producing titanium materials, and the oxygen content is an important indicator. At present, titanium materials are usually produced at home and abroad by adding titanium-containing residues. Residue addition refers to the use of titanium and titanium alloy residues instead of sponge titanium for smelting when a vacuum consumable arc furnace or a cooling hearth furnace is used to smelt titanium and titanium alloys. The main forms of titanium and titanium alloy residues are: cutting, block residues, long strip scraps, ingot caps, round cake residues, etc. Due to the small amount of residues and large fluctuations in element content between different batches, there are large fluctuations in impurity components and poor quality of titanium billets during the titanium smelting process.

[0003] Chinese patent CN 214496452 ​​U discloses a titanium sponge oxygen enrichment device, including a feeding mechanism, a cooling mechanism, a heating furnace arranged between the feeding mechanism and the cooling mechanism, and a conveyor mesh belt connecting the feeding mechanism and the cooling mechanism, the conveyor mesh belt is used to convey titanium sponge, and runs through the inlet and outlet of the heating furnace, the heating furnace is evenly distributed with a first electric heating radiation tube, the heating furnace is provided with an air inlet pipe matching the cross section of the heating furnace near the outlet end, the air inlet pipe is evenly distributed with gas nozzles, a premixer and a preheater are provided outside the heating furnace, the premixer is provided with an oxygen inlet pipe, a protective gas inlet pipe and an oxygen analyzer, the preheater is evenly distributed with a second electric heating radiation tube, the preheater is provided with a temperature sensor, and the premixer, the preheater and the air inlet pipe are connected in sequence through pipelines. This technical solution can make the preheated mixed gas form a stable airflow in the opposite direction of the titanium sponge conveying direction, improve the oxygen enrichment effect of titanium sponge, and avoid the phenomenon of large fluctuations in oxygen content in titanium ingots.

[0004] Chinese patent CN 102816941 B discloses a process and device for producing high-oxygen titanium sponge, which controls the oxygen content in titanium tetrachloride to achieve the purpose of stabilizing the oxygen content in titanium sponge. According to the requirements of titanium alloy for oxygen content, titanium sponge with oxygen content that meets the requirements is produced, and titanium dioxide does not need to be added during the titanium sponge smelting process, thus avoiding the component segregation and local defects caused by the addition of titanium dioxide. At the same time, it also reduces the difficulty of alloy mixing, improves the uniformity of the composition and the stability of the quality of the titanium ingot, and effectively improves the performance of the titanium alloy material.

[0005] The existing technologies all obtain high-oxygen content titanium materials by adding oxygen during the titanium sponge smelting process, which not only adds extra steps but also increases the manufacturing cost of titanium materials. Therefore, there is an urgent need for a production method of high-oxygen content raw materials with uniform component elements for melting titanium alloys. Summary of the invention

[0006] In view of this, the present invention proposes a production method of titanium tetrachloride with high oxygen content specially used for smelting titanium alloy, which can make the component elements in titanium tetrachloride uniform from the source and ensure the quality of titanium materials.

[0007] In order to solve at least one of the above technical problems, the present invention adopts the following technical solution: According to the present invention, a method for producing a titanium tetrachloride product with a high oxygen content specially used for smelting titanium alloy is provided, comprising: a raw material preparation step, in which titanium slag and petroleum coke are pretreated so that the proportion of the titanium slag with a particle size of less than 0.1 mm is greater than 90%, and the proportion of the petroleum coke with a particle size of less than 0.15 mm is greater than 90%; a chlorination step, in which the pretreated titanium slag, petroleum coke and molten salt medium are added to a molten salt chlorination furnace, heated to 850-900°C, and chlorine gas is introduced for a chlorination reaction to generate a titanium tetrachloride product with a high oxygen content.

[0008] According to one embodiment of the present invention, in the raw material preparation process, the proportion of titanium slag with a particle size less than 0.05 mm is greater than 20%.

[0009] According to one embodiment of the present invention, in the raw material preparation process, the proportion of petroleum coke with a particle size less than 0.05 mm is greater than 20%.

[0010] According to one embodiment of the present invention, in the raw material preparation process, the moisture content of the petroleum coke is in the range of 0.6-0.8%.

[0011] According to one embodiment of the present invention, in the chlorination process, the moisture content of the molten salt medium is controlled in the range of 0.8-1.2%.

[0012] According to one embodiment of the present invention, in the chlorination process, the chlorine concentration is greater than 85%.

[0013] According to one embodiment of the present invention, in the chlorination process, the moisture content of the chlorine gas is controlled in the range of 0.1-0.2%.

[0014] According to one embodiment of the present invention, after the chlorination process is completed, the C content in the remaining molten salt is less than 1.5%, and the TiO2 content is less than 1%, calculated by mass percentage.

[0015] According to one embodiment of the present invention, the high oxygen content titanium tetrachloride product comprises titanium tetrachloride and at least one of the following components: COCl2, CO, CO2, CCl3COCl, CHCl2COCl, CH2ClCOCl and TiOCl2.

[0016] According to one embodiment of the present invention, the oxygen content of the high oxygen content titanium tetrachloride product is 0.04%-0.10% by mass.

[0017] By adopting the above technical solution, the present invention has at least one of the following advantages compared with the prior art: 1. According to the method of the present invention, titanium tetrachloride products with high oxygen content are produced by controlling the particle size, purity and chlorination reaction conditions of the raw materials, without the need to modify existing equipment, with low cost and convenient operation; 2. The high oxygen content titanium tetrachloride product produced according to the method of the present invention has uniform composition elements, which is conducive to ensuring the quality of subsequent titanium materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A flow chart of a method for producing a high-oxygen-content titanium tetrachloride product specifically for smelting titanium alloy according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0021] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0022] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] According to the present invention, a method for producing a titanium tetrachloride product with a high oxygen content specially used for melting titanium alloy is provided, such as Figure 1 As shown, the overall process includes the following steps: In the raw material preparation process, titanium slag and petroleum coke are pre-treated so that the proportion of titanium slag particles less than 0.1 mm is greater than 90%, and the proportion of petroleum coke particles less than 0.15 mm is greater than 90%; In the chlorination process, the pretreated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 850~900℃, and chlorine gas is introduced for chlorination reaction to generate a titanium tetrachloride product with a high oxygen content.

[0024] In the raw material preparation process, the purpose of pre-treating titanium slag and petroleum coke is to make them meet the requirements of appropriate particle size and purity. Titanium slag is the residue after ilmenite is smelted in an electric furnace to extract titanium iron. It is rich in titanium. Using titanium slag as a titanium source to produce titanium tetrachloride can realize the secondary utilization of waste and save production costs; petroleum coke is used as a reducing agent. In an embodiment of the present invention, it is preferred to control the proportion of titanium slag with a particle size less than 0.1mm to be greater than 90%, of which the proportion less than 0.05mm is greater than 20%; the proportion of petroleum coke with a particle size less than 0.15mm is greater than 90%, of which the proportion less than 0.05mm is greater than 20%. The moisture content of petroleum coke is preferably in the range of 0.6~0.8%. Titanium slag and petroleum coke within the above-mentioned particle size and purity range are conducive to uniform mixing and maintain high reaction activity.

[0025] In the chlorination process, the molten salt chlorination furnace uses molten salts such as sodium chloride or potassium chloride as a reaction medium for chlorination reaction. Pretreated titanium slag, petroleum coke, and sodium chloride as a molten salt medium are added to the molten salt chlorination furnace, and the molten salt in the furnace is heated by an AC heating electrode to raise the temperature of the molten salt to 850~900℃. Chlorine is introduced, and in the environment of molten salt, chlorine reacts with titanium oxide in titanium slag under the reducing atmosphere provided by petroleum coke to generate titanium tetrachloride gas and other chloride impurities, such as aluminum chloride, ferric chloride, etc. The main reaction formula can be expressed as: TiO2+2Cl2+C→TiCl4+CO2. Since molten salt has good heat and mass transfer properties, it can promote the full reaction, and the generated metal chloride can be further collected after escaping from the molten salt in gaseous form for subsequent production processes. In an embodiment of the present invention, the moisture content of sodium chloride as a reaction medium is preferably controlled in the range of 0.8~1.2%. Too much water not only affects the reaction efficiency, but also reacts with chlorine to produce corrosive substances such as hydrochloric acid, which affects the service life of the equipment. Too much water vapor mixed with titanium tetrachloride vapor will also affect the quality of the final product. If the moisture content of sodium chloride is reduced to below 0.8%, the molten salt needs to be strictly dried, such as long-term high-temperature drying, which consumes a lot of energy and is not conducive to reducing costs.

[0026] Further, in an embodiment of the present invention, the chlorination process needs to control the chlorine concentration to be greater than 85%, and the moisture content of the chlorine is controlled within the range of 0.1-0.2%. On the one hand, a higher chlorine concentration can accelerate the reaction rate, so that the reaction between the titanium-containing slag and the chlorine in the molten salt chlorination furnace proceeds more rapidly; on the other hand, a higher chlorine concentration helps the reaction proceed more fully, which can improve the conversion rate of the raw materials, reduce the residual raw materials, and increase the output of the metal chloride. A high moisture content will absorb a large amount of heat and vaporize, destroying the stable temperature field in the molten salt chlorination furnace, which is not conducive to the stable and continuous reaction; at high temperatures, moisture will react with chlorine to generate corrosive hydrochloric acid and other substances, which will corrode the furnace body of the molten salt chlorination furnace and the internal pipes, components, etc., shortening the service life of the equipment; and the side reactions caused by moisture are prone to produce impurities mixed into the final metal chloride product, resulting in reduced product purity.

[0027] After the chlorination process is completed, the remaining molten salt is mixed with incompletely reacted titanium slag, petroleum coke and incomplete decomposition products of the two. In an embodiment of the present invention, after the chlorination reaction is fully completed, the C content in the remaining molten salt is less than 1.5% and the TiO2 content is less than 1% by mass percentage. The obtained high-oxygen content titanium tetrachloride product contains at least one of COCl2, CO, CO2, CCl3COCl, CHCl2COCl, CH2ClCOCl and TiOCl2 in addition to pure titanium tetrachloride to increase the oxygen content of the high-oxygen content titanium tetrachloride product. The high-oxygen content titanium tetrachloride product produced by the method of the present invention can have an oxygen content of up to 0.04%-0.10%.

[0028] The following is a specific embodiment of the production method of a high oxygen content titanium tetrachloride product specially used for smelting titanium alloy according to the present invention and its specific process parameters.

[0029] Example 1 The production method of the titanium tetrachloride product with a high oxygen content dedicated to smelting titanium alloy in this embodiment comprises the following steps: In the raw material preparation process, titanium slag and petroleum coke are pretreated so that the particle size of titanium slag is less than 0.1mm, accounting for 95%, and the particle size is less than 0.05mm, accounting for 25%; the particle size of petroleum coke is less than 0.15mm, accounting for more than 93%, and the particle size is less than 0.05mm, accounting for 22%. The moisture content of petroleum coke is 0.6%.

[0030] In the chlorination process, the pretreated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 850°C, and chlorine gas is introduced for chlorination reaction to generate titanium tetrachloride products with high oxygen content. Among them, the moisture content of sodium chloride is 0.9%, the concentration of chlorine gas is 87%, and the moisture content of chlorine gas is 0.15%.

[0031] After the chlorination process is completed, the C content in the remaining molten salt is 1.4%, and the TiO2 content is 0.8%. According to measurement, the oxygen content of the high oxygen content titanium tetrachloride product obtained using this embodiment is 0.08%.

[0032] Example 2 The production method of the titanium tetrachloride product with a high oxygen content dedicated to smelting titanium alloy in this embodiment comprises the following steps: In the raw material preparation process, titanium slag and petroleum coke are pretreated so that the particle size of titanium slag is less than 0.1mm, accounting for 92%, and the particle size is less than 0.05mm, accounting for 23%; the particle size of petroleum coke is less than 0.15mm, accounting for more than 97%, and the particle size is less than 0.05mm, accounting for 25%. The moisture content of petroleum coke is 0.8%.

[0033] In the chlorination process, the pretreated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 860°C, and chlorine gas is introduced for chlorination reaction to generate a high oxygen content titanium tetrachloride product. Among them, the moisture content of sodium chloride is 1.2%, the concentration of chlorine gas is 90%, and the moisture content of chlorine gas is 0.12%.

[0034] After the chlorination process is completed, the C content in the remaining molten salt is 1.2%, and the TiO2 content is 0.5%. According to measurement, the oxygen content of the high oxygen content titanium tetrachloride product obtained using this embodiment is 0.10%.

[0035] Example 3 The production method of the titanium tetrachloride product with a high oxygen content dedicated to smelting titanium alloy in this embodiment comprises the following steps: In the raw material preparation process, titanium slag and petroleum coke are pretreated so that the particle size of titanium slag is less than 0.1mm, accounting for 90%, and the particle size is less than 0.05mm, accounting for 25%; the particle size of petroleum coke is less than 0.15mm, accounting for more than 90%, and the particle size is less than 0.05mm, accounting for 22%. The moisture content of petroleum coke is 0.6%.

[0036] In the chlorination process, the pretreated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 880°C, and chlorine gas is introduced for chlorination reaction to generate a high oxygen content titanium tetrachloride product. Among them, the moisture content of sodium chloride is 1.0%, the concentration of chlorine gas is 95%, and the moisture content of chlorine gas is 0.16%.

[0037] After the chlorination process is completed, the C content in the remaining molten salt is 1.0%, and the TiO2 content is 0.6%. According to measurement, the oxygen content of the high oxygen content titanium tetrachloride product obtained using this embodiment is 0.04%.

[0038] Example 4 The production method of the titanium tetrachloride product with a high oxygen content dedicated to smelting titanium alloy in this embodiment comprises the following steps: In the raw material preparation process, titanium slag and petroleum coke are pretreated so that the particle size of titanium slag is less than 0.1mm, accounting for 92%, and the particle size is less than 0.05mm, accounting for 23%; the particle size of petroleum coke is less than 0.15mm, accounting for more than 97%, and the particle size is less than 0.05mm, accounting for 25%. The moisture content of petroleum coke is 0.7%.

[0039] In the chlorination process, the pre-treated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 880°C, and chlorine gas is introduced for chlorination reaction to generate titanium tetrachloride products with high oxygen content. Among them, the moisture content of sodium chloride is 0.7%, the concentration of chlorine gas is 88%, and the moisture content of chlorine gas is 0.18%.

[0040] After the chlorination process is completed, the C content in the remaining molten salt is 0.8%, and the TiO2 content is 0.9%. According to measurement, the oxygen content of the high oxygen content titanium tetrachloride product obtained using this embodiment is 0.075%.

[0041] Example 5 The production method of the titanium tetrachloride product with a high oxygen content dedicated to smelting titanium alloy in this embodiment comprises the following steps: In the raw material preparation process, titanium slag and petroleum coke are pretreated so that the particle size of titanium slag is less than 0.1mm, accounting for 92%, and the particle size is less than 0.05mm, accounting for 23%; the particle size of petroleum coke is less than 0.15mm, accounting for more than 97%, and the particle size is less than 0.05mm, accounting for 25%. The moisture content of petroleum coke is 0.7%.

[0042] In the chlorination process, the pretreated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 860°C, and chlorine gas is introduced for chlorination reaction to generate a high oxygen content titanium tetrachloride product. Among them, the moisture content of sodium chloride is 1.2%, the concentration of chlorine gas is 90%, and the moisture content of chlorine gas is 0.12%.

[0043] After the chlorination process is completed, the C content in the remaining molten salt is 1.1%, and the TiO2 content is 0.5%. According to measurement, the oxygen content of the high oxygen content titanium tetrachloride product obtained using this embodiment is 0.06%.

[0044] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

[0046] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for producing a high oxygen content titanium tetrachloride product for smelting titanium alloy, characterized in that: include: In the raw material preparation process, titanium slag and petroleum coke are pre-treated so that the proportion of titanium slag particles less than 0.1 mm is greater than 90%, and the proportion of petroleum coke particles less than 0.15 mm is greater than 90%; In the chlorination process, the pretreated titanium slag, petroleum coke and molten salt medium are added to the molten salt chlorination furnace, heated to 850~900℃, and chlorine gas is introduced for chlorination reaction to generate a titanium tetrachloride product with a high oxygen content.

2. The method according to claim 1, characterized in that In the raw material preparation process, the proportion of titanium slag with a particle size less than 0.05 mm is greater than 20%.

3. The method according to claim 1, characterized in that In the raw material preparation process, the proportion of petroleum coke with a particle size less than 0.05 mm is greater than 20%.

4. The method according to claim 3, characterized in that In the raw material preparation process, the moisture content of petroleum coke ranges from 0.6 to 0.8%.

5. The method according to claim 1, characterized in that In the chlorination process, the moisture content of the molten salt medium is controlled in the range of 0.8-1.2%.

6. The method according to claim 5, characterized in that In the chlorination process, the chlorine concentration is greater than 85%.

7. The method according to claim 6, characterized in that In the chlorination process, the moisture content of the chlorine gas is controlled in the range of 0.1-0.2%.

8. The method according to claim 1, characterized in that After the chlorination process is completed, the C content in the remaining molten salt components is less than 1.5% and the TiO2 content is less than 1% by mass percentage.

9. The method according to claim 1, characterized in that: The high oxygen content titanium tetrachloride product comprises titanium tetrachloride and at least one of the following components: COCl2, CO, CO2, CCl3COCl, CHCl2COCl, CH2ClCOCl and TiOCl2.

10. The method according to claim 1, characterized in that In terms of mass percentage, the oxygen content of the high oxygen content titanium tetrachloride product is 0.04%-0.07%.

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