An oxidizing furnace and its feeding ring for titanium dioxide chloride production

Abstract

The application discloses an oxidation furnace and a feeding ring thereof for titanium white powder production, and the oxidation furnace feeding ring comprises a main pipe, a first branch pipe, a second branch pipe, a first rectifying section, a second rectifying section, a first ring gap and a second ring gap; wherein one end of the main pipe is provided with a first outlet and a second outlet; the first outlet of the main pipe is detachably connected with the first branch pipe, and the first branch pipe is connected to the first rectifying section and the first ring gap in sequence; the second outlet of the main pipe is connected with the second branch pipe; and the second branch pipe is connected to the second rectifying section and the second ring gap in sequence. The oxidation furnace adopts the first branch pipe and the second branch pipe to add titanium tetrachloride in sections, the first branch pipe is detachable and replaceable, the scab before the ring gap of the oxidation furnace is reduced, the stable operation of the oxidation furnace is favorable, and the adjustment of the particle size of different titanium white powder products is realized.

Description

Technical Field

[0001] This invention belongs to the field of titanium dioxide production technology, and particularly relates to an oxidation furnace and its feeding ring for the production of titanium dioxide. Background Technology

[0002] In the production process of titanium dioxide by the chloride process, titanium tetrachloride undergoes a gas-phase oxidation reaction to obtain titanium dioxide particles. After passing through a pipeline for cooling and gas-solid separation, the particles are then pulped and subjected to post-processing steps similar to those of the sulfuric acid process.

[0003] Titanium tetrachloride oxidation is a crucial step in the preparation of titanium dioxide because the oxidation furnace is the core equipment in the chlorination process for titanium dioxide production. The reactor's structure, airflow mixing characteristics, and process operating conditions determine the final quality of the titanium dioxide.

[0004] Currently, the feeding ring of the oxidation furnace in the titanium dioxide chlorination industry mainly uses a single titanium tetrachloride feeding channel to mix and react with oxygen. This results in scaling in the contact area of ​​the raw materials and the subsequent reaction area, which can easily lead to production stoppages due to pipeline blockage. At the same time, the adjustment capability of the single-channel feeding device is limited, making it impossible to produce multiple titanium dioxide products with different particle sizes from a single oxidation furnace.

[0005] In summary, the titanium dioxide industry urgently needs an oxidation furnace that can solve the scaling problem and produce titanium dioxide products with multiple particle sizes. Summary of the Invention

[0006] Based on this, in order to overcome the shortcomings of the existing technology, an oxidation furnace and its feeding ring for the production of titanium dioxide chloride are provided. The present invention effectively solves the above problems by using a feeding ring with dual feeding channels, and has a good prospect for promotion and application in the titanium dioxide chloride industry.

[0007] To achieve the above objectives, the following technical solution is adopted:

[0008] The present invention provides a feeding ring for an oxidation furnace used in the production of titanium dioxide with chloride, the feeding ring comprising a main pipe, a first branch pipe, a second branch pipe, a first rectifier section, a second rectifier section, a first annular gap, and a second annular gap;

[0009] The main pipe has a first outlet and a second outlet at one end; the first outlet of the main pipe is detachably connected to the first branch pipe, which is sequentially connected to the first rectifier section and the first annular gap.

[0010] The second outlet of the main pipe is connected to the second branch pipe; the second branch pipe is connected in sequence to the second rectifier section and the second annular gap;

[0011] Titanium tetrachloride enters the feeding ring of the oxidation furnace through the main pipe, and then enters the mixing reaction zone of the oxidation furnace through the first and second annular gaps to undergo an oxidation reaction with oxygen.

[0012] Furthermore, the oxidation furnace feeding ring also includes:

[0013] A raw material inlet is provided for inputting titanium tetrachloride; the raw material inlet is located at one end of the main pipe.

[0014] Furthermore, the first outlet of the main pipe is located above the second outlet.

[0015] Furthermore, the first annular slit is positioned further forward than the second annular slit in the direction of oxygen flow, so that titanium tetrachloride entering the mixing reaction zone from the first annular slit reacts with oxygen first, compared to titanium tetrachloride entering the mixing reaction zone from the second annular slit.

[0016] Furthermore, the first branch pipe is connected to the first outlet of the main pipe via a flange to allow for the replacement of first branch pipes of different diameters.

[0017] Furthermore, the second outlet of the main pipe is fixedly connected to the second branch pipe. Preferably, the second outlet of the main pipe and the second branch pipe are fixedly connected by welding.

[0018] Furthermore, the ratio of the diameter of the first branch pipe to the diameter of the second branch pipe is in the range of 1:5 to 1:20.

[0019] The present invention also provides an oxidation furnace for the production of titanium dioxide with chloride. The oxidation furnace is used to perform an oxidation reaction of titanium tetrachloride mixed with oxygen and to discharge chlorine and titanium dioxide. The oxidation furnace includes a toluene combustion chamber, an oxidation furnace feeding ring as described above, a mixing reaction zone, and an AlCl3 generator. The toluene combustion chamber is connected to the mixing reaction zone, and the AlCl3 generator is connected to the raw material inlet of the feeding ring. The toluene combustion chamber allows oxygen to be introduced into the mixing reaction zone of the oxidation furnace. The AlCl3 generator allows preheated titanium tetrachloride to be introduced into the AlCl3 generator to react with aluminum powder and then introduced into the oxidation furnace feeding ring, so that titanium tetrachloride enters the mixing reaction zone through the first ring gap and the second ring gap to undergo an oxidation reaction with oxygen.

[0020] Furthermore, the mixing reaction zone also includes:

[0021] An oxygen inlet is provided for introducing oxygen from the toluene combustion chamber into the mixing reaction zone of the oxidation furnace.

[0022] The titanium dioxide and chlorine generated after the oxidation reaction are exported through the product outlet to the subsequent system.

[0023] The present invention also provides a method for producing titanium dioxide by means of an oxidation furnace as described above, the method comprising:

[0024] Titanium tetrachloride is preheated with oxygen;

[0025] Start the toluene lance in the oxidizer, introduce oxygen into the toluene combustion chamber of the oxidizer to react together, and then enter the feeding ring;

[0026] Preheated titanium tetrachloride is passed into an AlCl3 generator to react with aluminum powder, and then passed into the feeding ring of an oxidation furnace.

[0027] Titanium tetrachloride enters the first annular gap through the first branch pipe, thereby reacting with oxygen in the mixed reaction zone. The generated titanium dioxide and the remaining oxygen are transported to the vicinity of the second annular gap and further react with the titanium tetrachloride that enters the oxidation furnace through the second annular gap.

[0028] After the reaction, titanium dioxide and chlorine are generated and then enter the subsequent system for gas-solid separation.

[0029] The present invention has the following beneficial technical effects:

[0030] The oxidation furnace of the present invention uses a first branch pipe and a second branch pipe to add titanium tetrachloride in stages, so that it reacts with oxygen in stages to generate titanium dioxide. The titanium dioxide generated by the reaction of titanium tetrachloride under the first branch pipe with oxygen washes the wall of the reaction zone near the second annular seam under the second branch pipe, reducing the scaling in front of the annular seam of the oxidation furnace and facilitating the stable operation of the oxidation furnace.

[0031] The first branch pipe of the oxidation furnace of the present invention is detachable and replaceable. By adjusting the diameter of the first branch pipe, different segmented feeding ratios can be achieved, thereby adjusting the particle size of different titanium dioxide products. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of an oxidation furnace according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the feeding ring of an oxidation furnace according to an embodiment of the present invention.

[0035] [List of Labels in the Attached Image]

[0036] 1-Oxidation furnace, 2-Oxygen inlet, 4-Product outlet;

[0037] 5-Main pipe, 6-First branch pipe, 7-Second branch pipe, 8-First rectifier section, 9-Second rectifier section, 10-First annular joint, 11-Second annular joint. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0039] Scaling is one of the main problems affecting the normal operation of oxidation reactors. Scaling in oxidation furnaces is caused by the gradual sintering of newly formed aerosol-like titanium dioxide particles with a large surface area and viscosity, and flocculent material remaining in the high-temperature zone, forming hard scalds. Scaling changes the spatial shape of the oxidation furnace, blocks the feed port, and affects the airflow direction, often forcing the furnace to be shut down for treatment.

[0040] like Figure 1 As shown, the oxidation furnace 1 used in this embodiment for the production of titanium dioxide is used to perform an oxidation reaction of titanium tetrachloride and oxygen and to discharge chlorine and titanium dioxide. The oxidation furnace 1 includes a toluene combustion chamber, an oxidation furnace feeding ring, a mixing reaction zone, and an AlCl3 generator. The toluene combustion chamber is connected to the mixing reaction zone, and the AlCl3 generator is connected to the raw material inlet of the feeding ring. The toluene combustion chamber allows oxygen to enter the mixing reaction zone of the oxidation furnace through oxygen port 2. The AlCl3 generator allows preheated titanium tetrachloride to be fed into the AlCl3 generator to react with aluminum powder and then fed into the oxidation furnace feeding ring.

[0041] like Figure 2 As shown, the mixing reaction zone also includes:

[0042] Oxygen inlet: The oxygen inlet is used to introduce oxygen from the toluene combustion chamber into the mixing reaction zone of the oxidation furnace;

[0043] Product export 4: The titanium dioxide and chlorine generated after the oxidation reaction are sent to the subsequent system through the product export.

[0044] Figure 2 Also shown is an oxidation furnace feeding ring for the production of titanium dioxide with chloride, the oxidation furnace feeding ring including a main pipe 5, a first branch pipe 6, a second branch pipe 7, a first rectifier section 8, a second rectifier section 9, a first annular slot 10, and a second annular slot 11;

[0045] One end of the main pipe 5 is provided with a first outlet and a second outlet, with the first outlet of the main pipe 5 located above the second outlet.

[0046] The first outlet of the main pipe 5 is detachably connected to the first branch pipe 6, which is connected in sequence to the first rectifier section 8 and the first annular gap 10.

[0047] The second outlet of the main pipe 5 is connected to the second branch pipe 7; the second branch pipe 7 is connected in sequence to the second rectifier section 9 and the second annular gap 11.

[0048] Titanium tetrachloride enters the feeding ring of the oxidation furnace through the main pipe 5, and then enters the mixing reaction zone of the oxidation furnace through the first annular gap 10 and the second annular gap 11 to undergo an oxidation reaction with oxygen.

[0049] The raw material inlet is used to input titanium tetrachloride; the raw material inlet is located at one end of the main pipe 5.

[0050] like Figure 2 As shown, with the oxygen flow direction as the reference, the first annular slit 10 is positioned further forward than the second annular slit 11, i.e., closer to the oxygen inlet. Thus, although titanium tetrachloride enters the reaction zone through both the first and second annular slits 10, it reacts with oxygen first, compared to titanium tetrachloride entering through the second annular slit 11. The titanium dioxide generated from the reaction of titanium tetrachloride with oxygen under the first branch pipe 6 scours the wall of the reaction zone near the second annular slit 11 under the second branch pipe 7, reducing scaling in front of the annular slits of the oxidizer and promoting stable operation of the oxidizer.

[0051] The first branch pipe 6 is connected to the first outlet of the main pipe 5 via a flange, allowing for the replacement of branch pipes 6 with different diameters. The second outlet of the main pipe 5 is fixedly connected to the second branch pipe 7. Preferably, the second outlet of the main pipe 5 and the second branch pipe 7 are fixedly connected by welding. Therefore, the second branch pipe 7 has a fixed diameter.

[0052] The ratio of the diameter of the first branch pipe 6 to the diameter of the second branch pipe 7 is in the range of 1:5 to 1:20. The first branch pipe 6 of the oxidation furnace of this invention is detachable and replaceable. By adjusting the diameter of the first branch pipe 6, different segmented feeding ratios can be achieved, thereby adjusting the particle size of different titanium dioxide products. For example, it is necessary to achieve different segmented titanium tetrachloride feeding ratios by adjusting the ratio range of the diameter of the first branch pipe 6 to the diameter of the second branch pipe 7.

[0053] The methods for producing titanium dioxide using the above-mentioned oxidation furnace include:

[0054] Titanium tetrachloride is preheated with oxygen in a preheating furnace to reach the required process temperature range during production.

[0055] Start the toluene gun in the oxidizer, introduce oxygen into the toluene combustion chamber of the oxidizer to react together, and then enter the feeding ring so that the oxygen and titanium tetrachloride can reach the oxidation reaction temperature;

[0056] Preheated titanium tetrachloride is passed into an AlCl3 generator to react with aluminum powder, and then passed into the feeding ring of an oxidation furnace.

[0057] Titanium tetrachloride enters the first annular slit 10 through the first branch pipe 6, thereby reacting with oxygen in the mixing reaction zone. The generated titanium dioxide and the remaining oxygen are transported to the vicinity of the second annular slit 11 and react further with the titanium tetrachloride that enters the oxidation furnace through the second annular slit 11. In the reaction chamber, the high-temperature oxygen flow mixes with the preheated gaseous titanium tetrachloride and the crystal conversion agent AlCl3 and reacts rapidly, generating rutile titanium dioxide through reaction and nucleation.

[0058] After the reaction, titanium dioxide and chlorine are generated and then enter the subsequent system for gas-solid separation.

[0059] like Figure 2 As shown, the preheated gaseous titanium tetrachloride and the crystal conversion agent AlCl3 mixture enters the first annular gap 10 and the second annular gap 11 tangentially from the first branch pipe 6 and the second branch pipe 7. The axial high-temperature oxygen-containing flow mixes and reacts with the preheated gaseous titanium tetrachloride and the crystal conversion agent AlCl3 in a cross jet at a certain angle.

[0060] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. Although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0061] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A feed ring for an oxidation furnace for the production of chlorinated titanium white pigment, characterized in that, The oxidizer feeding ring includes a main pipe, a first branch pipe, a second branch pipe, a first rectifier section, a second rectifier section, a first annular gap, a second annular gap, and a raw material inlet; The main pipe has a first outlet and a second outlet at one end; the first outlet of the main pipe is detachably connected to the first branch pipe, which is sequentially connected to the first rectifier section and the first annular gap. The second outlet of the main pipe is connected to the second branch pipe; the second branch pipe is connected in sequence to the second rectifier section and the second annular gap; The raw material inlet is used to input titanium tetrachloride; the raw material inlet is located at one end of the main pipe; The first outlet of the main pipe is located above the second outlet; Titanium tetrachloride enters the feeding ring of the oxidation furnace through the main pipe, and enters the mixing reaction zone of the oxidation furnace through the first annular gap and the second annular gap to undergo oxidation reaction with oxygen; wherein, the first annular gap is set further forward than the second annular gap in the direction of oxygen flow, so that the titanium tetrachloride entering the mixing reaction zone through the first annular gap reacts with oxygen first compared to the titanium tetrachloride entering the mixing reaction zone through the second annular gap.

2. The feeding ring for an oxidation furnace used in the production of titanium dioxide according to claim 1, characterized in that, The first branch pipe is connected to the first outlet of the main pipe via a flange to allow for the replacement of the first branch pipe with different diameters.

3. The feeding ring for an oxidation furnace used in the production of titanium dioxide according to claim 1, characterized in that, The second outlet of the main pipe is fixedly connected to the second branch pipe.

4. The feeding ring for an oxidation furnace used in the production of titanium dioxide according to claim 1, characterized in that, The ratio of the diameter of the first branch pipe to the diameter of the second branch pipe is in the range of 1:5 to 1:

20.

5. An oxidation furnace for the production of titanium dioxide with chloride, characterized in that, The oxidation furnace is used to oxidize titanium tetrachloride by mixing it with oxygen and then discharge chlorine and titanium dioxide. The oxidation furnace includes a toluene combustion chamber, an oxidation furnace feeding ring as described in any one of claims 1-4, a mixing reaction zone, and an AlCl3 generator. The toluene combustion chamber is connected to the mixing reaction zone, and the AlCl3 generator is connected to the raw material inlet of the feeding ring. The toluene combustion chamber allows oxygen to enter the mixing reaction zone of the oxidation furnace. The AlCl3 generator allows preheated titanium tetrachloride to react with aluminum powder before entering the oxidation furnace feeding ring, so that titanium tetrachloride enters the mixing reaction zone through the first and second annular gaps to undergo an oxidation reaction with oxygen. The first annular gap is positioned further forward than the second annular gap in the direction of oxygen flow, so that titanium tetrachloride entering the mixing reaction zone through the first annular gap reacts with oxygen first, compared to titanium tetrachloride entering the mixing reaction zone through the second annular gap.

6. The oxidation furnace for producing titanium dioxide according to claim 5, characterized in that, The mixing reaction zone further includes: An oxygen inlet is provided for introducing oxygen from the toluene combustion chamber into the mixing reaction zone of the oxidation furnace. The titanium dioxide and chlorine generated after the oxidation reaction are exported through the product outlet to the subsequent system.

7. A method for producing titanium dioxide by means of an oxidation furnace as described in any one of claims 5-6, characterized in that, The method includes: Titanium tetrachloride is preheated with oxygen; Start the toluene lance in the oxidizer, introduce oxygen into the toluene combustion chamber of the oxidizer to react together, and then enter the feeding ring; Preheated titanium tetrachloride is passed into an AlCl3 generator to react with aluminum powder, and then passed into the feeding ring of an oxidation furnace. Titanium tetrachloride enters the first annular gap through the first branch pipe, thereby reacting with oxygen in the mixed reaction zone. The generated titanium dioxide and the remaining oxygen are transported to the vicinity of the second annular gap and further react with the titanium tetrachloride that enters the oxidation furnace through the second annular gap. After the reaction, titanium dioxide and chlorine are generated and then enter the subsequent system for gas-solid separation.

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