Reconstruction method of anosovite of chlorination process titanium dioxide oxidation unqualified primary product and anosovite

Abstract

The invention relates to the technical field of metallurgy, in particular to an anosovite reconstruction method for a chlorination process titanium dioxide oxidation unqualified primary product and anosovite, and the reconstruction method comprises the following steps: step 1, dechlorinating the chlorination process titanium dioxide oxidation unqualified primary product to obtain a first mixture; 2, the first mixture and petroleum coke are mixed, ground and smashed, and a second mixture is obtained; 3, adding a solvent into the second mixture to obtain a third mixture; 4, the third mixture is subjected to heat preservation for a first time at the first temperature, and a melt is obtained; and step 5, cooling the melt to room temperature by adopting gradient cooling to obtain anosovite. According to the reconstruction method disclosed by the invention, the problems of resource waste and low grade rate caused by unqualified primary products produced due to factors such as starting and stopping in the current production process are effectively solved.

Description

Technical Field

[0001] This disclosure relates to the field of metallurgical technology, and in particular to a method for reconstructing black titanium dioxide from substandard primary products obtained by oxidation of titanium dioxide produced by the chloride process, and black titanium dioxide itself. Background Technology

[0002] Titanium dioxide (TiO2) produced by the chloride process is characterized by high purity, uniform particle size (0.2-0.3 μm), and strong stability. Its core advantages lie in its environmental friendliness (no waste acid pollution from the sulfuric acid process) and superior product performance (superior hiding power and weather resistance compared to sulfuric acid process products), leading to its widespread application in coatings, plastics, papermaking, and other fields. The production process of titanium dioxide via the chloride process mainly includes four steps: chlorination of titanium raw materials to produce titanium tetrachloride (TiCl4); distillation purification to remove impurities; gas-phase oxidation to produce TiO2 particles; and surface coating treatment to enhance application performance.

[0003] However, in the current chloride process for titanium dioxide production, due to factors such as start-up and shutdown, and fluctuations in equipment operation, approximately 5-8% of the initial titanium dioxide product exhibits quality problems such as incomplete crystal structure and uneven particle size, and is therefore deemed substandard. From an economic cost perspective, the industry currently handles these substandard initial products primarily in two ways: first, by mixing them into qualified initial products in a certain proportion for subsequent processing, which negatively impacts the quality of the final product and reduces its market competitiveness; second, by downgrading the substandard initial products for reuse, which not only results in a serious waste of resources but also makes it difficult to improve the grade of titanium dioxide production, thus hindering the economic benefits of enterprises.

[0004] Based on the above, how to effectively solve the problem of handling substandard initial products in the production of titanium dioxide using the chloride process, and achieve efficient resource utilization and improved product quality rate, is a problem that those skilled in the art need to consider. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides a method for reconstructing black titanium dioxide from substandard oxidized titanium dioxide produced by the chloride process, and the black titanium dioxide itself. This addresses the existing problem of effectively handling substandard oxidized titanium dioxide in the chloride process, achieving efficient resource utilization and improved product quality.

[0006] To address the aforementioned technical problems, some embodiments of the present invention disclose a method for reconstructing black titanium dioxide from substandard initial products obtained through the chloride process, comprising the following steps: Step 1: Dechlorinate the substandard titanium dioxide produced by the chloride process to obtain the first mixture; Step 2: Mix the first mixture with petroleum coke and grind it to obtain the second mixture; Step 3: Add solvent to the second mixture to obtain the third mixture; Step 4: Hold the third mixture at the first temperature for the first time to obtain a melt; Step 5: Cool the melt to room temperature using a gradient cooling method to obtain black titanium stone.

[0007] In some embodiments, in step 1: the dechlorination treatment includes adding hydrogen peroxide solution to the unqualified initial product of titanium dioxide oxidized by the chloride process.

[0008] In some embodiments, the hydrogen peroxide solution has a mass percentage concentration of 27%, and the mass percentage of hydrogen peroxide to the unqualified titanium dioxide oxidized raw product is 0.005%-0.02%:1.

[0009] In some embodiments, in step 2, the mass ratio of the first mixture to the petroleum coke is 3:1 to 2:1.

[0010] In some embodiments, in step 2, the first mixture is mixed with petroleum coke and ground to a particle size of 100μm-500μm to obtain a second mixture.

[0011] In some embodiments, the solvent is a CaO-MgO based solvent.

[0012] In some embodiments, the first temperature is 1000℃-2000℃.

[0013] In some embodiments, in step 4, the first time is 2-6 hours.

[0014] In some embodiments, in step 5, the cooling rate of the gradient cooling is 50℃ / min-10℃ / min.

[0015] On the other hand, some embodiments of the present invention also disclose a black titanium stone, which is prepared by the above-mentioned method for reconstructing black titanium stone from unqualified primary products of titanium dioxide oxidized by the chloride process.

[0016] By adopting the above technical solution, the present invention has at least the following beneficial effects: 1. This invention reduces and smelts substandard titanium dioxide produced by the chloride process into black titanium dioxide through a series of process steps, including dechlorination, mixing and grinding, high-temperature melting, and gradient cooling. This effectively solves the problems of resource waste and low grade rate caused by substandard initial products produced due to start-up and shutdown in the current production process, and provides a brand-new strategy and idea for the industrial treatment of substandard initial products.

[0017] 2. This reduction smelting process directly converts high-valence titanium oxides in substandard primary products into low-valence titanium oxides under a weak reducing atmosphere. Compared with the traditional high-temperature strong reduction process, it significantly reduces energy consumption and the emission of harmful gases during the reduction process, thus reducing environmental pollution.

[0018] 3. The prepared black titanium stone forms a stable solid solution structure, which stabilizes the valence state of titanium and exhibits excellent chemical stability. This black titanium stone is more suitable for the production of titanium dioxide or sponge titanium, and is better compatible with downstream production processes, significantly improving the production efficiency of downstream processes.

[0019] 4. This invention not only optimizes the processing path for substandard titanium dioxide produced by the chloride process, avoiding the impact of substandard initial products on the quality of final products, but also realizes the high-value utilization of resources, improves the economic benefits and market competitiveness of enterprises, and has broad prospects for industrial application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method for reconstructing black titanium dioxide from substandard titanium dioxide produced by the chloride process, according to an embodiment of this disclosure. Detailed Implementation

[0022] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0023] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0024] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0025] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0026] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0027] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0028] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0029] In the current chloride process for titanium dioxide production, due to factors such as start-up and shutdown, and fluctuations in equipment operation, approximately 5-8% of the initial titanium dioxide product exhibits quality problems such as incomplete crystal structure and uneven particle size, and is therefore deemed substandard. From an economic cost perspective, the industry currently handles these substandard initial products primarily in two ways: first, by mixing them into qualified initial products in a certain proportion for subsequent processing, which negatively impacts the quality of the final product and reduces its market competitiveness; second, by downgrading the substandard initial products for reuse, which not only results in a serious waste of resources but also makes it difficult to improve the grade of titanium dioxide production, thus hindering the economic benefits of enterprises.

[0030] Therefore, such as Figure 1 As shown, some embodiments of the present invention disclose a method for reconstructing black titanium dioxide from substandard primary products obtained through the chloride process, comprising the following steps: Step 1: Dechlorinate the substandard titanium dioxide produced by the chloride process to obtain the first mixture; Step 2: Mix the first mixture with petroleum coke and grind it to obtain the second mixture; Step 3: Add solvent to the second mixture to obtain the third mixture; Step 4: Hold the third mixture at the first temperature for the first time to obtain a melt; Step 5: Cool the melt to room temperature using a gradient cooling method to obtain black titanium stone.

[0031] In the above method, step 1: the dechlorination treatment includes adding hydrogen peroxide solution to the unqualified initial product of titanium dioxide oxidized by the chlorination process.

[0032] In the above method, the mass percentage concentration of hydrogen peroxide solution is 27%, and the mass percentage of hydrogen peroxide to the unqualified titanium dioxide oxidant is 0.005%-0.02%:1.

[0033] In the above method, in step 2, the mass ratio of the first mixture to petroleum coke is 3:1-2:1.

[0034] In the above method, in step 2, the first mixture is mixed with petroleum coke and ground to a particle size of 100μm-500μm to obtain the second mixture.

[0035] In the above method, in step 3, the solvent is a CaO-MgO solvent.

[0036] In the above method, in step 4, the first temperature is 1000℃-2000℃.

[0037] In the above method, in step 4, the first time is 2-6 hours.

[0038] In the above method, in step 5, the cooling rate of the gradient cooling is 50℃ / min - 10℃ / min. Some embodiments of the present invention also disclose a black titanium stone, which is prepared by the above-mentioned method for reconstructing black titanium stone from unqualified initial products of titanium dioxide oxidized by the chloride process.

[0039] Example: In Examples 1 to 5 of this invention, 100 grams of substandard titanium dioxide oxidized by the chloride process were taken and prepared as black titanium dioxide according to the above method. The hydrogen peroxide concentration was 27%, and the mass ratio of hydrogen peroxide to the substandard titanium dioxide oxidized by the chloride process was 0.015%:1. The process parameters for the examples are shown in Table 1, and the quality and reduction rate of the prepared black titanium stone are shown in Table 2.

[0040] Table 1: Process Parameters of Examples

[0041] Table 2: Black Titanium Stone Mass and Reduction Rate in Examples

[0042] Comparative example: Comparative Examples 1-2: 100g of unqualified titanium dioxide produced by the chloride process was oxidized without dechlorination (no hydrogen peroxide solution was added), and the other preparation steps were consistent with the method disclosed herein.

[0043] Comparative Examples 3-4: 100g of unqualified titanium dioxide oxidized by the chloride process was taken. Step 3 of the method disclosed in this disclosure was not performed (no solvent was added). The other preparation steps were the same as those in this disclosure. The hydrogen peroxide concentration was 27%, and the mass ratio of hydrogen peroxide to unqualified titanium dioxide oxidized by the chloride process was 0.015%.

[0044] The process parameters for the comparative example are shown in Table 3, and the quality and reduction rate of the prepared black titanium stone are shown in Table 4.

[0045] Table 3: Comparative Example Process Parameters

[0046] Table 4: Comparative Black Titanium Stone Mass and Reduction Rate

[0047] Due to the characteristics of the process, the initial product of titanium dioxide produced by the chloride process, which fails to meet oxidation standards, contains 0.5%-1.2% residual Cl. - (Mainly existing in the form of TiCl4 adsorbed state, surface chloride salts, etc.), in the method disclosed herein, a 27% hydrogen peroxide solution (mass ratio 0.005%-0.02%) is added for dechlorination. Hydrogen peroxide, as a strong oxidant, can react with residual low-valent chlorides (such as TiCl3) in the initial product to generate water-soluble HCl (TiCl3 + H2O2 + H2O → TiO2 + 3HCl). Subsequently, the HCl is volatilized and removed through water washing or drying, so that Cl... - The residual amount decreased.

[0048] In the method disclosed herein, dechlorination treatment is used to avoid Cl... - At high temperatures, it reacts with petroleum coke (C) to produce highly toxic Cl2 or organochlorides (such as CCl4), while simultaneously preventing Cl... - It reacts with CaO-MgO flux to produce CaCl2, due to excess Cl - This leads to an abnormally high flux viscosity, affecting oxygen ion conduction efficiency. Furthermore, the dechlorination treatment ensures the surface activity of the initial product, and residual Cl... -Cl- will adsorb onto the surface of TiO2 particles, blocking their reactive sites with petroleum coke. Dechlorination treatment can remove the surface adsorption layer, improving the specific surface area utilization of TiO2 particles and laying the foundation for subsequent reduction reactions. Unremoved Cl- - The petroleum coke adsorbs onto the surface of TiO2 particles, preventing effective contact between the petroleum coke and TiO2. See Example 1 (72.2% reduction rate after dechlorination) and Comparative Example 1 (44.2% reduction rate without dechlorination).

[0049] In addition, without dechlorination, the residual Cl in the initial product at high temperatures (1000℃-2000℃) - It will be converted into Cl2, HCl, etc. In order to ensure that the emissions meet the standards, high-cost tail gas treatment equipment is required, which increases the production cost. The generated Cl2 and HCl gases are highly corrosive. If the equipment is not sealed properly (such as the furnace door of the silicon molybdenum furnace), it will lead to pipeline corrosion and leakage, causing safety accidents.

[0050] In this disclosed method, CaO and MgO are added at a high temperature of 1000℃-2000℃ to form a eutectic system. This system can form a stable molten medium within the process temperature range, encapsulating TiO2 and petroleum coke particles, eliminating contact gaps between solid particles, and transforming the reduction reaction from a localized surface reaction to a homogeneous overall reaction. The molten CaO-MgO has excellent oxygen ion conductivity, which can accelerate the migration of oxygen atoms in TiO2 to the surface of petroleum coke, reducing the activation energy of the reduction reaction. Refer to Example 1 (72.2% reduction rate after dechlorination) and Comparative Example 3 (49.3% reduction rate without dechlorination).

[0051] In summary, without dechlorination, the reduction rate drops to around 45%, potentially leading to excessive emissions of harmful gases, equipment corrosion and product degradation in downstream applications, and loss of process safety and stability. Without the addition of CaO-MgO flux, the reduction rate drops to around 50%, resulting in increased energy consumption, deterioration of the purity and stability of black titanium, loss of compatibility with downstream applications, and decreased process stability and environmental friendliness. Ultimately, this transforms the proposed technical solution from an environmentally friendly and efficient resource recycling technology into a highly polluting, high-risk, and high-cost ineffective process.

[0052] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0053] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A method for reconstructing black titanium dioxide from substandard primary products obtained through the chloride process of titanium dioxide oxidation, characterized in that, Includes the following steps: Step 1: Dechlorinate the substandard titanium dioxide produced by the chloride process to obtain the first mixture; Step 2: Mix the first mixture with petroleum coke and grind it to obtain the second mixture; Step 3: Add solvent to the second mixture to obtain a third mixture; Step 4: The third mixture is kept at a first temperature for a first time to obtain a melt; Step 5: The melt is cooled to room temperature using a gradient cooling method to obtain black titanium stone.

2. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 1, characterized in that, In step 1: the dechlorination treatment includes adding hydrogen peroxide solution to the unqualified initial product of titanium dioxide produced by the chloride process.

3. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 2, characterized in that, The hydrogen peroxide solution has a mass percentage concentration of 27%, and the mass percentage of hydrogen peroxide to the unqualified titanium dioxide oxidized product is 0.005%-0.02%:

1.

4. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 3, characterized in that, In step 2, the mass ratio of the first mixture to the petroleum coke is 3:1 to 2:

1.

5. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 4, characterized in that, In step 2, the first mixture is mixed with petroleum coke and ground to a particle size of 100μm-500μm to obtain the second mixture.

6. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 5, characterized in that, In step 3, the solvent is a CaO-MgO solvent.

7. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 6, characterized in that, In step 4, the first temperature is 1000℃-2000℃.

8. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 7, characterized in that, In step 4, the first time is 2-6 hours.

9. The method for reconstructing black titanium dioxide from substandard primary products obtained by the chloride process titanium dioxide oxidation according to claim 8, characterized in that, In step 5, the cooling rate of the gradient cooling is 50℃ / min-10℃ / min.

10. A type of black titanium stone, characterized in that, include: The method described in any one of claims 1-9 for reconstructing black titanium dioxide from substandard initial products obtained by oxidizing titanium dioxide using the chloride process is as follows.

Images