A rotary table filtering device and filtering method for improving concentration of titanium liquid

Abstract

The application discloses a rotary table filtering device and filtering method for improving titanium liquid concentration, relates to the field of titanium liquid, and comprises a filter disc, a feeding port and a discharging spiral, characterized in that the filter disc comprises a plurality of filter plates, the filter plates are provided with filter screens, the lower end of the filter disc is provided with a cam mechanism, the cam mechanism is in contact with the filter screens, and the cam mechanism makes the filter screens concave downward or convex upward. The filter screens are concave downward or convex upward through the cam mechanism, the filter cake on the filter screens is rapidly separated, the second blade is moved up and down and rotated, the rapid separation of the filter cake is accelerated, water is sprayed from below and the side of the second blade to flush the inside of the filter cake, the contact area of ferrous sulfate and water is increased, and the titanium liquid concentration is improved under the action of less water.

Description

Technical Field

[0001] This invention relates to the field of titanium dioxide, and more specifically to a rotary table filtration device and filtration method for increasing the concentration of titanium liquid. Background Technology

[0002] In the sulfuric acid process for titanium dioxide production, titanium liquor needs to be crystallized to separate ferrous sulfate heptahydrate crystals. This separation is usually achieved by rotary vacuum filtration. The quality of the rotary vacuum filtration device directly affects the residual titanium content in the ferrous sulfate, thus affecting the titanium yield.

[0003] The mixture of titanium liquid and ferrous sulfate is commonly known as crystallization slurry. After most of the ferrous sulfate heptahydrate is removed by vacuum filtration on a rotary table, the titanium liquid after ferrous sulfate removal is concentrated with steam to meet the requirements of the hydrolysis process. After hydrolysis, a white metatitanic acid precipitate is obtained and enters the next process.

[0004] Ferrous sulfate adsorbs a large amount of soluble titanium dioxide. As a byproduct of the sulfuric acid process for titanium dioxide production, ferrous sulfate is used in feed production where high purity is required. At the same time, the high adsorption of titanium dioxide by ferrous sulfate crystals also leads to a decrease in the titanium dioxide yield of the sulfuric acid process for titanium dioxide, thus affecting the production cost of titanium dioxide.

[0005] When the crystallizing slurry is separated from ferrous sulfate by a turntable, the fine crystal particles can cause the filter cloth to become clogged during filtration, resulting in low permeability of the filter cloth. In addition, the fine crystals have a large surface area and adsorb a much larger amount of titanium than the coarse crystal particles. Therefore, the fine crystal particles are also the main reason for the high residual titanium content in the separated ferrous sulfate crystals.

[0006] Existing processes, such as the vacuum rotary table filter described in application number 202122983327.3, use one or more scrapers and corresponding spray pipes to progressively wash and filter out ferrous heptahydrate crystals in multiple layers, reducing the titanium content entrained in the ferrous sulfate. By incorporating a compressed air backflushing component, the ferrous sulfate clogged in the filter cloth pores is cleared, achieving continuous high-efficiency filtration. While this process increases the contact area between ferrous sulfate and water by scraping the filter cake in multiple layers, each layer is compressed together, and a large amount of titanium dioxide remains adsorbed between the crystal particles. Furthermore, multiple scraping processes require water spraying, consuming a significant amount of water and failing to effectively increase the titanium concentration in the filtrate. Summary of the Invention

[0007] One object of the present invention is to provide a rotary table filter device and filtration method for increasing the concentration of titanium liquid. The filter cake is separated by a cam mechanism and a filter screen that can be concave downward and convex upward, thereby increasing the contact area between ferrous sulfate and water and thus increasing the concentration of titanium liquid.

[0008] This objective is achieved using the following technical solution:

[0009] A rotary table filtration device for increasing the concentration of titanium liquid is disclosed. Existing filtration devices typically include a filter disc, an inlet, and a discharge screw. The inventors have divided the filter disc into several filter plates, each with a filter screen. A cam mechanism is located at the lower end of the filter disc. This cam mechanism acts on the filter screen, causing the downwardly concave screen to convex upwards. As the filter cake is pushed upwards by the filter screen, it cracks, thereby increasing the contact area between the ferrous sulfate and water within the filter cake. A spray mechanism is installed on the filter plate, located directly above the cam mechanism. The water sprayed by the spray mechanism acts on the separated filter cake.

[0010] In existing processes, multiple layers of filter cake are scraped off to increase the contact area between ferrous sulfate and water. However, after scraping, each layer of filter cake adheres to the surface, consuming a large amount of water and preventing the adhered ferrous sulfate from contacting the water. In this process, the filter screen is initially concave downwards. The crystallized slurry is filtered on the filter screen, and a filter cake is formed on the concave screen under vacuum filtration. A cam mechanism rotates, causing the filter screen to bulge upwards and act on the filter cake on the screen, forcing the filter cake to separate from the inside, thus increasing the contact area between ferrous sulfate and water.

[0011] Furthermore, a stirring mechanism is provided on the filter plate. The stirring mechanism includes a first actuating rod, the lower end of which is connected to a first blade. A second actuating rod is fitted onto the first actuating rod, and a second blade is provided on the second actuating rod. The second actuating rod can move up and down on the first actuating rod, and the first and second actuating rods rotate coaxially. Driven by the filter disc, the filter cake rotates on the filter plate. When the filter cake rotates to the position of the first and second actuating rods, the cam mechanism pushes the filter screen upward, and at the same time, the first and second actuating rods insert into the filter cake from the side, accelerating the separation of the filter cake.

[0012] Simultaneously, when the cam mechanism causes the filter screen to bulge upwards, the filter screen contacts the lower end of the first blade. The first and second actuating rods rotate coaxially. The rotation of the first blade acts on the filter screen, separating the fine particles and crystals on the filter cloth from the filter cloth and preventing clogging. At the same time, the rotation of the second blade acts on the inside of the filter cake, accelerating the separation of the filter cake. During the rotation, the second actuating rod moves up and down on the first actuating rod, thereby driving the second blade to rotate circumferentially while moving up and down, improving the separation inside the filter cake.

[0013] Secondly, existing spraying mechanisms are positioned above the filter cake. After the filter cake is scraped off, it is sprayed through the spraying mechanism. In this invention, the first and second blades each have a first water spray hole on their sides, and the lower surfaces of both blades have a second water spray hole. The first and second actuating rods are internally connected, and the upper end of the second actuating rod is connected to the spraying mechanism. The first water spray holes on the sides of the first blades spray onto the filter screen, initially separating fine crystal particles. The second water spray holes on the lower surfaces of the first blades spray onto the filter screen from top to bottom, accelerating the separation of fine crystal particles from the filter screen.

[0014] This invention also includes a rotary table filtration method for increasing the concentration of titanium liquid, comprising:

[0015] The crystallization slurry is sprayed into the filter disc through the feed inlet;

[0016] The filter disc rotates, and under the action of vacuum filtration, filter cake is formed on several filter plates of the filter disc;

[0017] The cam mechanism causes the filter screen on the filter plate to sink downwards or bulge upwards, causing the filter cake to crack.

[0018] The rotation of the filter disc causes the sides of the first and second actuating rods to insert into the filter cake, and drives the first and second blades to rotate. The second blades move up and down with the second actuating rod, causing the filter cake to separate.

[0019] Water is sprayed from below and to the sides of the first and second blades to rinse the filter cake. The temperature of the water sprayed from below and to the sides of the first blade is greater than 30 degrees Celsius.

[0020] The rotating area of ​​the first and second blades is the inscribed circle of the filter plate, which increases the working area of ​​the first and second blades on the filter plate. The sides of the first and second action rods are provided with sharp points to facilitate quick insertion into the filter cake.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] This invention discloses a rotary table filtration device and filtration method for increasing the concentration of titanium liquid. The cam mechanism causes the filter screen to be concave downward or convex upward, which enables the filter cake on the filter screen to be separated quickly. Then, the up-and-down movement and rotation of the second blade accelerates the rapid separation of the filter cake. Furthermore, water is sprayed from below and to the side of the second blade to rinse the inside of the filter cake, which increases the contact area between ferrous sulfate and water. With a small amount of water, the concentration of titanium liquid is increased.

[0023] Meanwhile, water sprayed from the first blade and below and to the side of the first blade acts on the filter screen to prevent the filter cloth from being clogged by fine crystal particles. At the same time, rinsing the fine crystals can effectively avoid the problem of high residual titanium content in the separated ferrous sulfate crystals. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0025] Figure 1 This is a schematic diagram of the device structure in Example 1;

[0026] Figure 2 This is a schematic diagram of the downward-recessed structure of the filter screen in Example 1;

[0027] Figure 3 This is a schematic diagram of the upward-protruding structure of the filter screen in Example 1;

[0028] Figure 4 This is a schematic diagram of the stirring mechanism in Example 2;

[0029] Figure 5 This is a schematic diagram of the second action rod structure in Example 2;

[0030] Figure 6 This is a schematic diagram of the structure in Example 2 where the tapered roller is located at the upper end of the worm.

[0031] Figure 7 This is a schematic diagram of the structure in Example 2 where the tapered roller is located at the lower end of the worm.

[0032] Figure 8 This is a schematic diagram of the lower end structure of the filter screen and the first blade in Example 2, showing the downward concave filter screen.

[0033] Figure 9 This is a schematic diagram of the structure in Example 2 where the filter screen protrudes upwards and contacts the lower end of the first blade;

[0034] Figure 10 This is a schematic diagram of the structure in Example 2 where the first blade has a first water spray hole on its side.

[0035] Figure 11 This is a schematic diagram of the structure in Example 2 where the lower end face of the first blade is provided with a second water spray hole.

[0036] The attached diagram shows the markings and corresponding component names:

[0037] 1-Filter plate, 2-Inlet, 3-Baffle, 4-Discharge screw, 5-Clamping plate, 6-Second action rod, 7-Second blade, 8-First action rod, 9-First blade, 10-Worm, 11-Conical roller, 12-Rotating rod, 13-Second connection, 14-First connecting rod, 15-Filter plate, 16-Filter screen, 17-Cam mechanism, 18-Second water spray hole, 19-First water spray hole, 20-Protrusion. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0039] In the description of this invention, it should be understood that the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0040] Example 1

[0041] This device includes a filter disc 1, a feed inlet 2, and a discharge screw 4, such as Figure 1 As shown, the filter disc 1 includes several filter plates 15, each of which is equipped with a filter screen 16. During vacuum filtration, the filter disc 1 rotates circumferentially, and the crystallizing slurry passes through the feed inlet onto the filter screen, forming a filter cake on the screen. The filtrate is then recovered through the filter screen. The filter plate 15 includes a clamping plate 5, and the filter screen 16 is disposed on the clamping plate 5.

[0042] A cam mechanism 17 is provided at the lower end of the filter disc 1. The cam mechanism includes a cam and a structure that rotates the cam circumferentially. When the minimum radial distance of the cam contacts the filter screen 16, such as... Figure 2 As shown, the filter screen 16 is concave downwards. When the maximum radial distance of the cam contacts the filter screen 16, as... Figure 3 As shown, the filter screen 16 protrudes upwards. The filter plate 15 is fan-shaped, and several filter plates form a circle. As the filter disc rotates, the cam acts on each filter screen.

[0043] In some embodiments, the device is equipped with a cam mechanism, which is located between the feed inlet 2 and the discharge screw 4. Under the action of vacuum filtration, the filter cake is compacted on the filter screen. When the filter plate with the filter cake rotates onto the cam mechanism, the cam of the cam mechanism rotates, and the maximum radial direction of the cam contacts the filter screen, causing the filter screen to bulge upward and the filter cake on the filter screen to separate. At the same time, the spraying mechanism located directly above the cam mechanism 17 sprays the separated filter cake and sprays the ferrous sulfate inside the filter cake over a large area to prevent a large amount of soluble titanium dioxide from being adsorbed on the ferrous sulfate and to increase the concentration of titanium liquid.

[0044] In some embodiments, the device is equipped with multiple cam mechanisms, which are evenly arranged between the feed inlet 2 and the discharge screw 4. Under the action of vacuum filtration, the filter cake is compacted on the filter screen. The cam mechanism causes the cam to rotate, and the minimum and maximum radial distances of the cam continuously contact the filter screen, forcing the filter cake to separate faster. With a small amount of water, ferrous sulfate is sprayed over a large area, increasing the concentration of titanium liquid.

[0045] Example 2

[0046] Based on the above embodiments, a stirring mechanism is provided on the filter plate 15, and the stirring mechanism is located directly above the cam mechanism, such as... Figure 4 As shown, the stirring mechanism includes a first actuating rod 8, the lower end of which is connected to a first blade 9. A second actuating rod 6 is mounted on the first actuating rod 8, and a second blade 7 is provided on the second actuating rod 6. The second actuating rod 6 can move up and down on the first actuating rod 8, and the first actuating rod 8 and the second actuating rod 6 can rotate coaxially. When the cam mechanism 17 causes the filter screen 16 to protrude upward, the filter screen 16 contacts the lower end of the first blade 9.

[0047] In some embodiments, such as Figure 5 As shown, a protrusion 20 is provided on the second actuating rod 6, and a sliding groove is provided on the first actuating rod 8. The protrusion 20 is located in the sliding groove. The second actuating rod 6 slides up and down on the first actuating rod through the protrusion. At the same time, when the first actuating rod or the second actuating rod rotates, the protrusion and the sliding groove drive the first actuating rod or the second actuating rod to rotate together.

[0048] In some embodiments, a first rotating gear is connected to the second actuating rod, and the first rotating gear meshes with the second actuating rod. The rotation of the first rotating gear causes the second actuating rod to move up and down on the first actuating rod. A second rotating gear is connected to the first actuating rod, and the circumferential rotation of the second rotating gear drives the first actuating rod and the second actuating rod to rotate.

[0049] In some embodiments, a first connecting rod 14 is provided on the filter disc 1, the upper end of a second actuating rod passes through the first connecting rod 14, and a worm gear 10 is provided at the upper end of the second actuating rod. A second connecting rod 13 is vertically connected to the first connecting rod 14, and a rotating rod 12 is connected to the second connecting rod 13. A tapered roller 11 with a certain weight is connected to the rotating rod 12. The tapered roller 11 is located inside the worm gear 10 and rotates inside the worm gear 10, generating friction for the transmission of input torque. The worm gear has helical motion and moves up and down on the first connecting rod 14. In the original state, such as Figure 6 As shown, the tapered roller 11 is located at the upper end of the worm. When the tapered roller 11 rotates, as... Figure 7As shown, the tapered roller 11 drives the worm gear 10 to rotate and move upward. The worm gear drives the second action rod 6 and the second blade 7 to move upward on the first action rod. At the same time, the second action rod drives the first action rod to rotate, and the first blade and the second blade rotate circumferentially.

[0050] During use, when the filter disc 1 rotates to the position of the first and second actuating rods, the sides of the first actuating rod 8 and the second actuating rod 6 are provided with pointed tips, such as... Figure 8 As shown, the first and second actuating rods are inserted into the filter cake from the side. The first and second blades rotate to separate the interior of the filter cake, and the second blade 7 moves up and down to further separate the interior of the filter cake. When the filter disc 1 rotates to the position of the first and second actuating rods, the cam rotates simultaneously, as shown... Figure 9 As shown, when the filter screen 16 protrudes upward, the filter screen 16 contacts the lower end of the first blade 9, and the first blade rotates further to prevent small crystals from clogging the filter screen.

[0051] In some embodiments, such as Figure 10 As shown, both the first blade 9 and the second blade 7 have first spray holes 19 on their sides, such as... Figure 11 As shown, the lower end faces of the first blade 9 and the second blade 7 are both provided with second water spray holes 18. The first actuating rod 8 and the second actuating rod 6 are internally connected, and the upper end of the second actuating rod 6 is connected to the spraying mechanism. When the first blade and the second blade rotate inside the filter cake, water is sprayed out from their sides and lower end faces at the same time, which can further increase the contact area between water and ferrous sulfate and avoid the adsorption of high titanium dioxide by ferrous sulfate crystals.

[0052] Furthermore, the filter screen 16 is in contact with the lower end of the first blade 9, and the water sprayed from the lower end of the first blade acts directly on the filter screen to avoid clogging the filter screen.

[0053] In some embodiments, the device is also provided with a baffle 3, which is located between the feed inlet 2 and the discharge screw 4. The baffle 3 is used to block the filter cake on the filter screen and prevent the filter cake from moving when it interacts with the first and second action rods.

[0054] Example 3

[0055] Based on the above embodiments, a turntable filtration method for increasing the concentration of titanium liquid includes:

[0056] The crystallization slurry is sprayed into the filter plate 1 through the feed inlet 2. In this embodiment, the feed inlet 2 includes a discharge rod located on the filter screen. The discharge rod is provided with a plurality of outlets. The outlets are in contact with the filter screen. When discharging, the crystallization slurry is sprayed into the filter screen through the outlets.

[0057] The filter disc 1 rotates, and under the action of vacuum filtration, filter cake is formed on several filter plates 15 of the filter disc 1.

[0058] The cam mechanism 17 causes the filter screen 16 on the filter plate 15 to sink downwards or bulge upwards, causing the filter cake to crack.

[0059] The rotation of filter disc 1 causes the sides of the first actuating rod 8 and the second actuating rod 6 to insert into the filter cake, and drives the first blade 9 and the second blade 7 to rotate, thus separating the filter cake.

[0060] Water is sprayed from below and to the sides of the first blade 9 and the second blade 7 to rinse the filter cake.

[0061] The discharge screw 4 removes the filter cake from the filter screen.

[0062] The area where the first blade 9 and the second blade 7 rotate is the inscribed circle of the filter plate 15.

[0063] The temperature of the water sprayed from below and to the side of the first blade 9 is greater than 30 degrees Celsius.

[0064] In some embodiments, the feed rate of the crystallization slurry to filter disc 1 is 60m³. 3 / h, while adding washing water to filter screen 16, the temperature of the washing water is 35°, the rotation speed of filter disc 1 is 2min / r, and the ferrous sulfate prepared by this method has a residual titanium content of 0.18%, a water content of 18%, and a titanium solution concentration of 165g / L.

[0065] In some embodiments, the feed rate of the crystallization slurry to filter disc 1 is 55m³. 3 / h, while adding washing water to filter screen 16, the temperature of the washing water is 30°, the rotation speed of the disc is 2min / r, and the residual titanium of ferrous sulfate prepared by this method is 0.16%, the water content is 19%, and the titanium solution concentration is 163g / L.

[0066] In some embodiments, washing water is added to the filter screen 16 at a temperature of 34°C and a disc rotation speed of 2 min / r. The ferrous sulfate prepared by this method has a residual titanium content of 0.20%, a moisture content of 20%, and a titanium solution concentration of 161 g / L.

[0067] Example 3

[0068] Based on the above embodiments, a turntable filtration method for increasing the concentration of titanium liquid includes:

[0069] After filter disc 1 is running normally, control the disc rotation speed to 2-3 min / r;

[0070] The crystallization slurry is transported through a pipeline to inlet 2 for filtration, with a flow rate of 40-65 m³ / h. 3 / h;

[0071] Add 15%-20% of the volume of the crystallization slurry to the spray mechanism of filter plate 1, and the temperature of the turntable filtrate is 30-35°.

[0072] Washing is performed by introducing washing water into the spraying mechanism, and the amount of washing water per unit time is 6%-8% of the crystallization slurry.

[0073] As the filter disc 1 rotates, a filter cake is formed on several filter plates 15 of the filter disc 1 under the action of vacuum filtration.

[0074] The cam of the cam mechanism 17 rotates, causing the filter screen 16 on the filter plate 15 to be concave downward or convex upward, causing the filter cake to crack; the sides of the first action rod 8 and the second action rod 6 are inserted into the filter cake, and drive the first blade 9 and the second blade 7 to rotate, causing the filter cake to separate.

[0075] Washing water is sprayed from below and to the sides of the first blade 9 and the second blade 7 to rinse the filter cake.

[0076] The discharge screw 4 removes the filter cake from the filter screen.

[0077] Tests showed that the ferrous sulfate prepared by this method had a residual titanium content of 0.15%, a moisture content of 18%, and a titanium solution concentration of 165 g / L.

[0078] The terms "first," "second," and "third" used in this document are merely for clarity of description and are not intended to restrict any order or emphasize importance. Furthermore, the term "connection" used in this document, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0079] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotary table filtration device for increasing the concentration of molten titanium, comprising a filter disc (1), a feed inlet (2), and a discharge screw (4), characterized in that, The filter disc (1) includes several filter plates (15), on which filter screens (16) are provided. A cam mechanism (17) is provided at the lower end of the filter disc (1). The cam mechanism (17) contacts the filter screen (16) and causes the filter screen (16) to be concave downward or convex upward. A spraying mechanism is provided on the filter plate (15), and the spraying mechanism is located directly above the cam mechanism (17). A stirring mechanism is provided on the filter plate (15). The stirring mechanism includes a first action rod (8), the lower end of which is connected to a first blade (9). A second action rod (6) is fitted on the first action rod (8). (6) is provided with a second blade (7), the second action rod (6) can move up and down on the first action rod (8), and the first action rod (8) and the second action rod (6) rotate coaxially. When the cam mechanism (17) causes the filter screen (16) to bulge upward, the filter screen (16) contacts the lower end of the first blade (9); the sides of the first blade (9) and the second blade (7) are provided with first water spray holes (19), and the lower end surfaces of the first blade (9) and the second blade (7) are provided with second water spray holes (18). The interiors of the first action rod (8) and the second action rod (6) are connected, and the upper end of the second action rod (6) is connected to the spraying mechanism.

2. A rotary table filtration method for increasing the concentration of titanium liquid, characterized in that, The filtration device according to claim 1 includes: The crystallization slurry is sprayed into the filter plate (1) through the feed port (2); The filter disc (1) rotates, and under the action of vacuum filtration, filter cake is formed on several filter plates (15) of the filter disc (1); The cam mechanism (17) causes the filter screen (16) on the filter plate (15) to be recessed downwards or protruded upwards, causing the filter cake to crack.

3. The rotary table filtration method for increasing the concentration of titanium liquid according to claim 2, characterized in that, Also includes: The filter disc (1) rotates so that the sides of the first action rod (8) and the second action rod (6) are inserted into the filter cake, and drive the first blade (9) and the second blade (7) to rotate, so that the filter cake is separated.

4. The rotary table filtration method for increasing the concentration of titanium liquid according to claim 3, characterized in that, Also includes: Water is sprayed from below and to the sides of the first blade (9) and the second blade (7) to rinse the filter cake.

5. The rotary table filtration method for increasing the concentration of titanium liquid according to claim 2, characterized in that, The area circle in which the first blade (9) and the second blade (7) rotate is the inscribed circle of the filter plate (15).

6. The rotary table filtration method for increasing the concentration of titanium liquid according to claim 4, characterized in that, The temperature of the water sprayed from below and to the side of the first blade (9) is greater than 30 degrees.

7. The rotary table filtration method for increasing the concentration of titanium liquid according to claim 2, characterized in that, The sides of the first action rod (8) and the second action rod (6) are provided with sharp points.

Images