Device and method for separating titanium dioxide primary product and residual chlorine

Abstract

The invention discloses a device and method for separating a titanium dioxide primary product and residual chlorine, the device comprises an outer cylinder, a spiral assembly and a negative pressure device, the spiral assembly is arranged in the outer cylinder; the spiral assembly comprises an inner barrel and a spiral plate, the inner side edge of the spiral plate is fixed to the outer wall of the inner barrel in a threaded mode, and the outer side edge of the spiral plate is adjacent to the inner wall of the outer barrel; a vent hole penetrating into the outer cylinder body is formed in the inner cylinder body; a first end of the inner cylinder is provided with a gas inlet, and a second end of the inner cylinder is provided with a gas outlet; and the negative pressure equipment is communicated with the gas outlet. By arranging the negative pressure equipment, matching with the vent holes and combining with a spiral stirring and conveying feeding mode, the separation efficiency can be greatly improved, and the chlorine content on the surface of titanium dioxide can be greatly reduced. And the separated chlorine gas is collected, enriched and recycled, or is absorbed by alkali liquor, so that the harm of the chlorine gas to the environment and human bodies is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of titanium dioxide chloride production, and in particular to a device and method for separating primary titanium dioxide products from residual chlorine. Background Art

[0002] The principle of titanium dioxide production by the chloride process is mainly that titanium tetrachloride and oxygen directly oxidize at high temperature to obtain primary titanium dioxide and chlorine. Although most of the chlorine is removed by bag filter filtration in the current production process, there is still chlorine adsorbed on the surface of the primary titanium dioxide, causing a series of quality problems of the primary product, such as chloride ions entering the subsequent production process, resulting in lower pH, high viscosity and other problems. Therefore, removing the chlorine element in the form of chlorine at the beginning of production is beneficial to improving product quality and reducing subsequent production costs.

[0003] In the existing production of titanium dioxide by chloride process, there is little attention paid to residual chlorine and few treatment methods. Many enterprises only reduce the chlorine content by open-air stacking. However, chlorine volatilizes into the air, seriously endangering the environment and the health of personnel, and is inefficient and unsustainable. In addition, the residual chlorine in titanium dioxide reacts with water in the air to produce hydrochloric acid and hypochlorous acid, and the chlorine content is even more difficult to remove. Hydrogen peroxide and alkali solution are also required to adjust the pH value of the reaction system during the pulping stage. There are few devices and methods for separating residual chlorine from titanium dioxide by chloride process in the prior art. The difficulty lies in the small particle size of titanium dioxide by chloride process (180±20 nm) and the toxicity and corrosiveness of chlorine. Therefore, seeking a device or method that can remove the chlorine element when it is still in the form of chlorine gas in the early stage of production has become a research focus of technicians in this field.

[0004] Based on this, the existing technology still needs to be improved. Summary of the invention

[0005] In order to solve the above technical problems, the embodiments of the present invention provide a device and method for separating primary titanium dioxide from residual chlorine, so as to solve a series of technical problems caused by the presence of chloride ions in primary titanium dioxide products in the prior art.

[0006] In order to solve the above technical problems, on the one hand, some embodiments of the present invention disclose a device for separating primary titanium dioxide and residual chlorine, comprising an outer cylinder, a spiral component and a negative pressure device, wherein the spiral component is arranged in the outer cylinder; The spiral assembly comprises an inner cylinder and a spiral plate, the inner side edge of the spiral plate is fixed to the outer wall of the inner cylinder in a threaded shape, and the outer side edge of the spiral plate is adjacent to the inner wall of the outer cylinder; Furthermore, the inner cylinder is provided with a vent hole penetrating into the outer cylinder; The first end of the inner cylinder is provided with a gas inlet, and the second end of the inner cylinder is provided with a gas outlet; The negative pressure device is connected to the gas outlet. In some embodiments, an inert gas storage tank is further included, and the gas inlet is connected to the inert gas storage tank via an air inlet valve.

[0007] In some embodiments, the diameter of the vent hole is smaller than the particle size of the primary titanium dioxide product.

[0008] In some embodiments, a material inlet and a material outlet are respectively provided at both ends of the outer cylinder, and the material inlet and the gas outlet are located on the same side.

[0009] In some embodiments, a vibration pump is further included, wherein a vibration member of the vibration pump is on the outer wall of the outer cylinder.

[0010] In some embodiments, the vibration frequency of the vibration pump is 20-500 Hz.

[0011] In some embodiments, the outer cylinder, the inner cylinder and the spiral plate are made of stainless steel, nickel steel, zirconium alloy, titanium alloy or polytetrafluoroethylene.

[0012] On the other hand, an embodiment of the present invention further discloses a method for separating primary titanium dioxide products from residual chlorine, which is implemented by using the aforementioned device for separating primary titanium dioxide products from residual chlorine.

[0013] In some embodiments, as the material moves between the outer cylinder and the inner cylinder, the negative pressure device is intermittently activated and deactivated; Furthermore, when the negative pressure device is started, the air intake valve at the other end of the inner cylinder is closed, and when the negative pressure device is closed, the air intake valve at the other end of the inner cylinder is opened.

[0014] In some embodiments, the invention includes: Step 1: Open the valves at the material inlet and the material outlet respectively, and the spiral assembly rotates to drive the material to move from the material inlet to the material outlet between the outer cylinder and the inner cylinder; Step 2: close the air inlet valve at the gas inlet, and simultaneously open the negative pressure device for the first time, and maintain the negative pressure in the inner cylinder for a predetermined time; Step 3: close the negative pressure device and open the air inlet valve at the gas inlet to introduce inert gas into the inner cylinder to restore the pressure in the inner cylinder to the first pressure; Step 4: Repeat steps 2 and 3 until the material is transported.

[0015] By adopting the above technical solution, the present invention has at least the following beneficial effects: The present invention provides a device and method for separating primary titanium dioxide from residual chlorine. By setting negative pressure equipment, coordinating the setting of vents, and combining the feeding method of spiral stirring and conveying, the separation efficiency can be greatly improved and the chlorine content on the surface of titanium dioxide can be reduced. The separated chlorine gas can be collected, enriched and reused, or absorbed by alkali solution to reduce its harm to the environment and human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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 described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The present invention is a schematic diagram of the structure of a device for separating primary titanium dioxide and residual chlorine disclosed in some embodiments of the present invention.

[0018] Description of reference numerals: 1. Outer cylinder; 2. Inner cylinder; 3. Spiral plate; 4. Negative pressure equipment; 5. Inert gas storage tank; 6. Vibration pump; 7. Vent; 8. Gas inlet; 9. Gas outlet; 10. Material inlet; 11. Material outlet. DETAILED DESCRIPTION

[0019] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

[0020] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.

[0021] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0022] In addition, the words "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" does not mean vertical in the strict sense, but is within the tolerance range. "Parallel" does not mean parallel in the strict sense, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0023] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.

[0024] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.

[0025] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0026] like Figure 1As shown, some embodiments of the present invention disclose a device for separating primary titanium dioxide and residual chlorine, comprising an outer cylinder 1, a spiral assembly and a negative pressure device 4, wherein the spiral assembly is arranged in the outer cylinder 1, and is used to transport the primary titanium dioxide material (containing chlorine) from one side of the outer cylinder 1 to the other side; The spiral assembly may include an inner cylinder 2 and a spiral plate 3, the inner side edge of the spiral plate 3 being threadedly fixed to the outer wall of the inner cylinder 2, and the outer side edge of the spiral plate 3 being adjacent to the inner wall of the outer cylinder 1, and the rotation of the inner cylinder 2 drives the spiral plate 3 to rotate, thereby realizing the transportation of the titanium dioxide primary product, and its transportation principle is basically the same as that of the screw conveyor in the prior art; and, the inner cylinder 2 is provided with an air vent 7 penetrating into the outer cylinder 1, and the air vent 7 can realize the mutual communication of gas between the inner cavity of the inner cylinder 2 and the outside of the inner cylinder 2 (that is, the material conveying cavity formed between the inner cylinder 2 and the outer cylinder 1); the first end of the inner cylinder 2 is provided with a gas inlet 8, and the second end of the inner cylinder 2 is provided with a gas outlet 9; the negative pressure device 4 is connected to the gas outlet 9. When in use, the gas inlet 8 can be closed, the negative pressure device 4 can be opened, and the gas can be pumped outward at the gas outlet 9, thereby forming a negative pressure in the inner cavity of the inner cylinder 2, so that the pressure in the inner cavity of the inner cylinder 2 is greater than the pressure of the material conveying cavity outside the inner cylinder 2. Under the action of the pressure difference, the chlorine in the titanium dioxide primary product in the material conveying cavity diffuses / moves into the inner cylinder 2, and is finally discharged from the gas outlet 9 under the drive of the negative pressure device 4. Generally, a corresponding storage tank can be set to store the chlorine for subsequent reuse. At the same time, in order to ensure the normal progress of material transportation, after maintaining the negative pressure for a period of time, it is necessary to close the negative pressure device 4, and at the same time open the closed switch of the gas inlet 8, such as the air inlet valve, and the gas enters through the air inlet valve to restore the pressure balance inside and outside the inner cylinder 2, avoiding the difficulty of material movement caused by the negative pressure. This negative pressure state can be intermittent, and by controlling the length of the outer cylinder 1 and the inner cylinder 2, that is, the material conveying length, the chlorine in the titanium dioxide primary product can be better removed, and the separation between the two can be achieved. The negative pressure device 4 mentioned above can be any device that can form negative pressure, including but not limited to a vacuum pump and an exhaust fan, and the vacuum degree can be adjusted according to the operation status of the device.

[0027] In some embodiments of the present invention, a device for separating a primary titanium dioxide product from residual chlorine is disclosed. On the basis of the above embodiments, in order to avoid air from entering and adversely affecting the chlorine in the primary titanium dioxide product, an inert gas storage tank 5 may be provided, and the gas inlet 8 is connected to the inert gas storage tank 5 through an air inlet valve to replace the entry of air. Furthermore, in order to ensure the dryness of the primary titanium dioxide product and avoid the reaction of chlorine with moisture in the gas to increase the difficulty of separation, a drying component may be provided at the gas inlet 8 to dry the gas entering the inner cylinder 2. In order to prevent the primary titanium dioxide product from entering the inner cylinder 2 through the vent 7 under the action of negative pressure and causing a decrease in yield, generally, the diameter of the vent 7 is designed to be smaller than the particle size of the primary titanium dioxide product. Both the discharge of chlorine and the guarantee of the yield of the primary titanium dioxide product are achieved.

[0028] Specifically, in some embodiments of the present invention, a material inlet 10 and a material outlet 11 are respectively provided at both ends of the outer cylinder 1, and the material inlet 10 and the gas outlet 9 are located on the same side. That is, the material outlet 11 is on the same side as the gas inlet 8. The purpose of this design is to be able to better discharge the chlorine in the boring. Under the negative pressure state, due to the presence of the negative pressure device 4, the negative pressure at the gas outlet 9 is the largest, that is, when the material enters from the material inlet 10, it is subjected to a large negative pressure. At the same time, since it has just entered the screw feeder, the pressure it receives is limited, and the overall looseness is the largest, which is conducive to the derivation of chlorine, so that more chlorine can be separated smoothly at this stage. The separated chlorine is either collected and enriched for reuse, or absorbed by alkali solution to reduce its harm to the environment and human body.

[0029] A device for separating primary titanium dioxide and residual chlorine disclosed in some embodiments of the present invention, on the basis of the above embodiments, in order to prevent the primary titanium dioxide from adhering to the inner wall of the outer cylinder 1 and affecting the transportation, further includes a vibration pump 6, and the vibration part of the vibration pump 6 is on the outer wall of the outer cylinder 1. The vibration frequency of the vibration pump 6 is 20-500HZ. By vibrating the vibration pump 6, the chlorine discharge efficiency can be further improved. The material of the outer cylinder 1, the inner cylinder 2 and the spiral plate 3 is generally selected to be a material that does not affect the quality of the titanium dioxide product and / or corrosion resistance, such as stainless steel, nickel steel, zirconium alloy, titanium alloy or polytetrafluoroethylene. At the same time, pressure, temperature and flow sensors can be set at the gas inlet 8 and the gas outlet 9 as needed to adjust and control the pressure and temperature in the equipment at any time.

[0030] The embodiment of the present invention also discloses a method for separating primary titanium dioxide from residual chlorine, which is implemented by using the aforementioned device for separating primary titanium dioxide from residual chlorine. As the material moves between the outer cylinder 1 and the inner cylinder 2, the negative pressure device 4 is started and closed intermittently; and when the negative pressure device 4 is started, the air intake valve at the other end of the inner cylinder 2 is closed, and when the negative pressure device 4 is closed, the air intake valve at the other end of the inner cylinder 2 is opened.

[0031] When in use, a titanium dioxide and chlorine mixed system with a certain flow rate enters the gap between the outer cylinder 1 and the inner cylinder 2, i.e., the material conveying chamber, through the material inlet 10 at the gap between the outer cylinder 1 and the inner cylinder 2. Due to the push of the screw (screw assembly), the material moves forward outside the inner cylinder 2. Gas (including but not limited to inert gases such as nitrogen, dry air, etc.) enters the inner cylinder 2 through the gas inlet 8, and diffuses and purges the titanium dioxide containing chlorine to the outside through the small holes (vents 7) in the tube wall. The negative pressure device 4 is connected to the gas outlet 9 as an additional device to form a local negative pressure and improve the dechlorination efficiency. In addition, the outside of the outer cylinder 1 can be vibrated by setting a vibration pump 6 to promote the falling off of the titanium dioxide attached to the inner wall of the outer cylinder 1.

[0032] The embodiment of the present invention further discloses a method for separating primary titanium dioxide and residual chlorine, which, based on the above embodiment, comprises: Step 1: Open the valves at the material inlet and the material outlet respectively, and the spiral assembly rotates to drive the material to move from the material inlet to the material outlet between the outer cylinder and the inner cylinder; Step 2: close the air inlet valve at the gas inlet, and simultaneously open the negative pressure device for the first time, and maintain the negative pressure in the inner cylinder for a predetermined time; Step 3: close the negative pressure device and open the air inlet valve at the gas inlet to introduce inert gas into the inner cylinder to restore the pressure in the inner cylinder to the first pressure; Step 4: Repeat steps 2 and 3 until the material is transported.

[0033] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0034] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A device for separating primary titanium dioxide and residual chlorine, characterized in that: It comprises an outer cylinder, a spiral assembly and a negative pressure device, wherein the spiral assembly is arranged in the outer cylinder; The spiral assembly comprises an inner cylinder and a spiral plate, the inner side edge of the spiral plate is fixed to the outer wall of the inner cylinder in a threaded shape, and the outer side edge of the spiral plate is adjacent to the inner wall of the outer cylinder; Furthermore, the inner cylinder is provided with a vent hole penetrating into the outer cylinder; The first end of the inner cylinder is provided with a gas inlet, and the second end of the inner cylinder is provided with a gas outlet; The negative pressure device is connected to the gas outlet.

2. The device for separating primary titanium dioxide and residual chlorine according to claim 1, characterized in that: It also includes an inert gas storage tank, and the gas inlet is connected to the inert gas storage tank through an air inlet valve.

3. The device for separating primary titanium dioxide and residual chlorine according to claim 1, characterized in that: The diameter of the vent hole is smaller than the particle size of the primary titanium dioxide product.

4. The device for separating primary titanium dioxide and residual chlorine according to claim 1, characterized in that: A material inlet and a material outlet are respectively provided at both ends of the outer cylinder, and the material inlet and the gas outlet are located on the same side.

5. The device for separating primary titanium dioxide and residual chlorine according to claim 1, characterized in that: It also includes a vibration pump, wherein the vibration element of the vibration pump is on the outer wall of the outer cylinder.

6. The device for separating primary titanium dioxide and residual chlorine according to claim 5, characterized in that: The vibration frequency of the vibration pump is 20-500 Hz.

7. The device for separating primary titanium dioxide and residual chlorine according to claim 1, characterized in that: The outer cylinder, the inner cylinder and the spiral plate are made of stainless steel, nickel steel, zirconium alloy, titanium alloy or polytetrafluoroethylene.

8. A method for separating primary titanium dioxide and residual chlorine, characterized in that: The method is realized by using the device for separating primary titanium dioxide and residual chlorine as described in any one of claims 1 to 7.

9. The method for separating primary titanium dioxide and residual chlorine according to claim 8, characterized in that: As the material moves between the outer and inner cylinders, the negative pressure device is activated and shut down intermittently; Furthermore, when the negative pressure device is started, the air intake valve at the other end of the inner cylinder is closed, and when the negative pressure device is closed, the air intake valve at the other end of the inner cylinder is opened.

10. The method for separating primary titanium dioxide and residual chlorine according to claim 9, characterized in that: include: Step 1: Open the valves at the material inlet and the material outlet respectively, and the spiral assembly rotates to drive the material to move from the material inlet to the material outlet between the outer cylinder and the inner cylinder; Step 2: Close the air inlet valve at the gas inlet and open the negative pressure device for the first time to maintain the negative pressure in the inner cylinder for a predetermined time; Step 3: close the negative pressure device and open the air inlet valve at the gas inlet to introduce inert gas into the inner cylinder to restore the pressure in the inner cylinder to the first pressure; Step 4: Repeat steps 2 and 3 until the material is transported.

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