Method for producing TiCl4 through low-temperature chlorination of low-valent titanium

Abstract

The invention relates to the technical field of titanium chemical industry, and discloses a method for producing TiCl4 by low-temperature chlorination of low-valence titanium, which comprises the following steps: S1, adding a low-grade titanium-containing material and a carbonaceous reducing agent into a reduction furnace, and heating and smelting in the reduction furnace to obtain a low-valence titanium-containing material; s2, crushing the low-valence titanium-containing material; s3, adding the crushed low-valence titanium material into a low-temperature chlorination furnace for low-temperature preheating; and S4, heating to a reaction temperature, continuously introducing chlorination gas into the low-temperature chlorination furnace, and carrying out a low-temperature chlorination reaction to obtain TiCl4. According to the method, the low-grade titanium-containing material is reduced into the low-valence titanium-containing material, then the low-valence titanium-containing material is crushed, and finally the low-temperature chlorination reaction is performed to prepare TiCl4, so that the smelting power consumption of the reduction reaction is reduced, the problem of process economy is solved, and the TiCl4 is efficiently and selectively separated and extracted by performing the reaction in the low-temperature chlorination slag after crushing, and the extraction efficiency of titanium is improved.

Description

Technical Field

[0001] The invention relates to the technical field of titanium chemical industry, and in particular to a method for producing TiCl4 by low-valent titanium low-temperature chlorination. Background Art

[0002] Titanium tetrachloride (TiCl4), as an intermediate material for the production of titanium sponge and titanium dioxide, plays a vital role in its industrial development. At present, the main processes for producing titanium tetrachloride at home and abroad are boiling chlorination process and molten salt chlorination process. However, in recent years, high-grade titanium raw materials suitable for boiling chlorination process and molten salt chlorination process, such as high-titanium slag and rutile, are being consumed at an accelerated rate and are increasingly dependent on imports. It is particularly important to develop titanium extraction technology from low-grade titanium-containing materials.

[0003] Low-grade titanium-containing materials can be produced into titanium tetrachloride by low-temperature chlorination process. Although this technology has achieved breakthroughs in industrial application technology, there are still many problems. On the one hand, the high-temperature carbonization reaction has high smelting power consumption. In order to reduce the smelting power consumption, CN108866343B discloses a two-step reduction carbonization method of titanium-containing blast furnace slag. In the first step, more than 70% of the tetravalent Ti in the titanium-containing blast furnace slag is reduced to low-valent Ti. In the second step, the pre-reduced slag is heated to 1400℃~1600℃, and then a carbonaceous reducing agent is added for refining. This method can shorten the reduction cycle and reduce power consumption to a certain extent, but it still needs to be refined into TiC, and the power consumption is still high. On the other hand, during the low-temperature chlorination reaction, the target component TiC is partially wrapped inside the particles, resulting in a low overall titanium extraction rate. In order to improve the reaction efficiency of carbonized blast furnace slag, CN114058879B discloses a method for boiling chlorination of carbonized slag, which is to suspend fine particles and settle coarse particles in the carbonized slag by setting the air flow velocity to achieve coarse and fine separation, and then crush the coarse particles and re-chlorinate. Although this scheme improves the reaction efficiency to a certain extent through re-chlorination, it also makes the process and device of low-temperature chlorination complicated.

[0004] Therefore, there is a need in the prior art for improving the method for producing TiCl4 by low-temperature chlorination of low-valent titanium. Summary of the invention

[0005] In view of this, the purpose of the embodiments of the present invention is to propose a method for producing TiCl4 by low-temperature chlorination of low-valent titanium, so as to solve the problems of large-scale chlorination of CaO and MgO components, high power consumption of reduction reaction and low titanium conversion rate when preparing TiCl4 from low-grade titanium-containing materials, and to achieve the effect of green, efficient and economical separation and extraction of titanium resources from low-grade titanium-containing materials.

[0006] Based on the above purpose, the embodiment of the present invention provides a method for producing TiCl4 by low-valent titanium low-temperature chlorination, comprising the following steps: S1 low-grade titanium-containing material and carbonaceous reducing agent are added to a reduction furnace, and the temperature is increased in the reduction furnace to smelt to obtain low-value titanium-containing material; S2 crushes the low-valent titanium-containing materials; S3 adds the crushed low-valent titanium material into a low-temperature chlorination furnace for low-temperature preheating; After S4 is heated to the reaction temperature, chlorination gas is continuously introduced into the low-temperature chlorination furnace to carry out low-temperature chlorination reaction to obtain TiCl4.

[0007] In some embodiments, in S1, the low-grade titanium-containing material includes any one or more of titanium-containing blast furnace slag, low-grade titanium slag, rutile dust ash, and titanium slag dust ash.

[0008] In some embodiments, in S1, the carbonaceous reducing agent is any one or more of coke, lignite, and petroleum coke.

[0009] In some embodiments, in S1, the temperature of the reduction furnace for smelting is 1300-1800°C.

[0010] In some embodiments, in S1, in the low-valent titanium-containing material, the content of low-valent titanium is 3-60%, and the content of TiC is 3-10%, calculated by mass percentage.

[0011] In some embodiments, in S2, the particle size of the crushed low-valent titanium-containing material is 1-75 um, and the mass percentage is >70%.

[0012] In some embodiments, the crushed particle size range and proportion, measured by mass percentage, include any of the following: Low-price titanium materials with a particle size of 30-75um account for more than 70% by mass; The mass proportion of low-valent titanium materials with a particle size of 1~30um is greater than 70%.

[0013] In some embodiments, in S3, the low temperature preheating temperature is 300-500°C.

[0014] In some embodiments, in S4, the chlorination gas includes chlorine or a mixture of chlorine and nitrogen, the mass fraction of the chlorine is ≥50%, and the chlorine is any one of chlorine evaporated from liquid chlorine, electrolytic chlorine, and factory circulating chlorine.

[0015] In some embodiments, in S4, the reaction temperature is 400-600°C.

[0016] The present invention has at least the following beneficial technical effects: (1) The low-grade titanium-containing material is heated and smelted in a reduction furnace to obtain low-price titanium-containing material, which effectively reduces the smelting power consumption and ensures the process economy compared to producing titanium carbide slag.

[0017] (2) The low-valent titanium-containing materials are crushed to 1-75 um, ensuring that the titanium component of the low-valent titanium materials fully contacts and reacts with chlorine during the low-temperature chlorination process, thereby improving the efficiency of the chlorination reaction.

[0018] (3) The low-valent titanium-containing material undergoes a low-temperature chlorination reaction with chlorine gas at a reaction temperature of 400-600°C, which effectively inhibits the chlorination of CaO and MgO components, ensuring the stable and smooth process and the selective separation and extraction of titanium components. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] Figure 1 This is a schematic diagram of an embodiment of the method for producing TiCl4 by low-valent titanium low-temperature chlorination provided by the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0022] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0023] 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 places 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.

[0024] like Figure 1 The present invention provides a method for producing TiCl4 by low-temperature chlorination of low-valent titanium, comprising the following steps: S1 low-grade titanium-containing material and carbonaceous reducing agent are added to a reduction furnace, and the temperature is increased in the reduction furnace to smelt to obtain low-value titanium-containing material; S2 crushes the low-valent titanium-containing materials; S3 adds the crushed low-valent titanium material into a low-temperature chlorination furnace for low-temperature preheating; After S4 is heated to the reaction temperature, chlorination gas is continuously introduced into the low-temperature chlorination furnace to carry out low-temperature chlorination reaction to obtain TiCl4.

[0025] Further, in S1, the low-grade titanium-containing material includes any one or more of titanium-containing blast furnace slag, low-grade titanium slag, rutile dust, and titanium slag dust. The carbonaceous reducing agent is any one or more of coke, semi-coke, and petroleum coke.

[0026] Furthermore, the temperature of the heating smelting in the reduction furnace is 1300~1800℃. Since the low-grade titanium-containing material has poor fluidity below 1450℃, 1500~1700℃ is preferably used to ensure good fluidity of the slag during implementation. In the low-valent titanium-containing material obtained after smelting, the low-valent titanium content is 3~60% and the TiC content is 3~10% by mass percentage. In some embodiments, when high-titanium blast furnace slag is used alone for reduction, the low-valent titanium content is controlled to be 3~10% and the TiC content is 3~7%. When low-titanium blast furnace slag is selected and mixed with low-grade titanium slag, rutile dust removal ash, and titanium slag dust removal ash, or when medium-titanium blast furnace slag is selected and mixed with low-grade titanium slag, rutile dust removal ash, and titanium slag dust removal ash, the low-valent titanium content is controlled to be 10~60% and the TiC content is 3~10%.

[0027] Further, in S2, in terms of mass percentage, the particle size of the crushed low-valent titanium-containing material is mainly 1-75um, accounting for more than 70% by mass, and the crushed material can be a coarse-grained material (particle size of 75-30um), a fine-grained material (particle size of 30-1um) and a full-grained material (particle size of 1-75um). In some embodiments, in terms of mass percentage, the crushed particle size range and proportion are low-valent titanium-containing materials with a particle size of 30-75um, accounting for more than 70% by mass.

[0028] In other embodiments, in terms of mass percentage, the low-valent titanium-containing material with a particle size of 1-30 um accounts for more than 70% by mass.

[0029] Further, in S3, the low-temperature preheating temperature is 300-500° C. The preheating temperature of the low-valent titanium material should be higher than the triggering temperature of the low-temperature chlorination reaction of 300° C., and to ensure that the low-temperature chlorination reaction is stably triggered and the reaction proceeds rapidly, in some embodiments of the present invention, the low-valent titanium material in the low-temperature chlorination furnace is preheated to 300-500° C., and during implementation, the preheating temperature can be 400° C. and 450° C.

[0030] Furthermore, in S4, the chlorine gas introduced into the low-temperature chlorination furnace is one or more of chlorine gas evaporated from liquid chlorine, electrolytic chlorine, factory circulating chlorine, etc., and the mass fraction of the chlorine gas is ≥50%.

[0031] Only chlorine gas or a mixture of chlorine gas and nitrogen gas is introduced into the low-temperature chlorination furnace. When implementing, it is preferred to introduce a mixture of chlorine gas and nitrogen gas. On the one hand, when the chlorine gas is stopped, the nitrogen gas can maintain the fluidized state of the low-temperature chlorination furnace; on the other hand, the low-temperature chlorination reaction is intense, and the nitrogen gas can reduce the chlorine concentration. By adjusting the nitrogen ratio, the effect of adjusting the intensity of the reaction can be achieved.

[0032] The low-temperature chlorination reaction temperature is 400-600°C, preferably 500°C, so that the low-valent titanium-containing material and chlorine gas undergo a low-temperature chlorination reaction to obtain a reaction product with TiCl4 as the main component.

[0033] In summary, the method of producing TiCl4 by low-cost chlorination of low-valent titanium in the present invention, low-grade titanium-containing materials are reduced to low-value titanium-containing materials under low smelting power consumption conditions, and low-temperature chlorination reaction is carried out after crushing to selectively produce TiCl4, which effectively solves the problem of green, efficient and low-cost production of TiCl4 from low-grade titanium-containing materials. The invention can be promoted and applied to the technical fields of extracting titanium resources from titanium-containing blast furnace slag in Panxi and Chengde areas of my country, and extracting titanium resources from low-titanium blast furnace slag and medium-titanium blast furnace slag abroad, and can also provide technical references for the comprehensive utilization of low-grade co-existing resources.

[0034] The present invention will be further explained below in conjunction with specific embodiments.

[0035] Example 1 Step 1: high-titanium blast furnace slag is used as a low-grade titanium-containing material, and coke is used as a carbonaceous reducing agent and added into a reduction furnace, and the reduction furnace is heated and smelted to obtain a low-value titanium-containing material, and the reduction temperature is 1300°C; Step 2: crush the low-valent titanium-containing material, and the particle size of the carbide slag after crushing is 75-30um, and the mass proportion is greater than 70% (coarse particle size); Step 3: adding the crushed low-valent titanium material into a low-temperature chlorination furnace for low-temperature preheating, wherein the low-temperature preheating temperature is 300° C.; Step 4: Chlorine gas is introduced into the low-temperature chlorination furnace, and a low-temperature chlorination reaction is carried out in the chlorination furnace at a temperature of 400° C. to obtain a reaction product mainly composed of TiCl4.

[0036] Example 2 Step 1: high-titanium blast furnace slag is used as a low-grade titanium-containing material, and coke is used as a carbonaceous reducing agent and added into a reduction furnace, and the reduction furnace is heated and smelted to obtain a low-value titanium-containing material, and the reduction temperature is 1500°C; Step 2: crush the low-valent titanium-containing material, and the particle size of the carbide slag after crushing is 75-30um, and the mass proportion is greater than 70% (coarse particle size); Step 3: adding the crushed low-valent titanium material into a low-temperature chlorination furnace for low-temperature preheating, wherein the low-temperature preheating temperature is 400° C.; Step 4: Chlorine gas is introduced into the low-temperature chlorination furnace, and a low-temperature chlorination reaction is carried out in the chlorination furnace at a temperature of 500° C. to obtain a reaction product mainly composed of TiCl4.

[0037] Example 3 Step 1: high-titanium blast furnace slag is used as a low-grade titanium-containing material, and coke is used as a carbonaceous reducing agent and added into a reduction furnace, and the reduction furnace is heated and smelted to obtain a low-value titanium-containing material, and the reduction temperature is 1800°C; Step 2: crush the low-valent titanium-containing material, and the particle size of the carbide slag after crushing is 75-30um, and the mass proportion is greater than 70% (coarse particle size); Step 3: adding the crushed low-valent titanium material into a low-temperature chlorination furnace for low-temperature preheating, wherein the low-temperature preheating temperature is 500° C.; Step 4: introducing chlorine gas into the low-temperature chlorination furnace, and carrying out a low-temperature chlorination reaction in the chlorination furnace at a temperature of 600° C. to obtain a reaction product mainly composed of TiCl4.

[0038] The method of the present invention first reduces low-grade titanium-containing materials to low-valent titanium-containing materials, then crushes them, and finally performs low-temperature chlorination reaction to produce TiCl4, which not only reduces the smelting power consumption of the reduction reaction and solves the problem of process economy, but also reacts in low-temperature chlorination slag after crushing to efficiently and selectively separate and extract TiCl4, thereby improving the extraction efficiency of titanium.

[0039] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0040] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0041] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0042] 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 above embodiments of the present invention, 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 TiCl4 by low-temperature chlorination of low-valent titanium, characterized in that: include: S1: adding a low-grade titanium-containing material and a carbonaceous reducing agent into a reduction furnace, and heating and smelting in the reduction furnace to obtain a low-grade titanium-containing material; S2 crushes the low-valent titanium-containing material; S3: adding the crushed low-valent titanium material into a low-temperature chlorination furnace for low-temperature preheating; After S4 is heated to the reaction temperature, chlorination gas is continuously introduced into the low-temperature chlorination furnace to perform a low-temperature chlorination reaction to obtain TiCl4.

2. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S1, the low-grade titanium-containing material includes any one or more of titanium-containing blast furnace slag, low-grade titanium slag, rutile dust ash, and titanium slag dust ash.

3. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S1, the carbonaceous reducing agent is any one or more of coke, blue coke, and petroleum coke.

4. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S1, the temperature of the reduction furnace for smelting is 1300-1800°C.

5. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S1, in the low-valent titanium-containing material, the low-valent titanium content is 3-60% and the TiC content is 3-10% by mass.

6. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S2, the particle size of the crushed low-valent titanium-containing material is 1-75 um, and its mass percentage is greater than 70%.

7. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 6, characterized in that: In terms of mass percentage, the crushed particle size range and proportion include any of the following: The low-valent titanium-containing material with a particle size of 30-75 μm accounts for more than 70% by mass; The low-valent titanium-containing material with a particle size of 1-30 um accounts for more than 70% by mass.

8. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S3, the low temperature preheating temperature is 300~500℃.

9. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S4, the chlorination gas includes chlorine or a mixture of chlorine and nitrogen, the mass fraction of the chlorine is ≥50%, and the chlorine is any one of chlorine evaporated from liquid chlorine, electrolytic chlorine, and factory circulating chlorine.

10. The method for producing TiCl4 by low-valent titanium low-temperature chlorination according to claim 1, characterized in that: In S4, the reaction temperature is 400-600°C.

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