Acidolysis tail gas treatment device for titanium dioxide production

Abstract

The utility model relates to the technical field of chemical production, and particularly discloses an acidolysis tail gas treatment device for titanium dioxide production, which comprises an obliquely arranged re-spraying pipeline, a plurality of water washing nozzles uniformly arranged at the top in the re-spraying pipeline, and a plurality of water washing nozzles arranged at the top in the re-spraying pipeline, the flow dividing groove is communicated with the bottom of the re-spraying pipeline and is used for carrying out gas-liquid separation; the pressure tank is communicated with the flow dividing groove; the alkaline washing tower is communicated with the pressure tank, a throttle valve is arranged between the pressure tank and the alkaline washing tower, and a plurality of alkaline washing nozzles are arranged in the alkaline washing tower; and the emptying chimney is communicated with the top of the alkaline washing tower, so that the problem that the acidolysis tail gas is difficult to realize stable up-to-standard emission due to unstable intermittent acidolysis tail gas emission in the traditional titanium dioxide production is solved.

Description

Technical Field

[0001] The present application relates to the technical field of chemical production, and specifically discloses an acidolysis tail gas treatment device for titanium dioxide production. Background Art

[0002] Titanium dioxide is an important inorganic chemical pigment, the main component of which is titanium dioxide. There are two production processes for titanium dioxide: the sulfuric acid process and the chlorination process. In the process of preparing titanium dioxide by the sulfuric acid process, ferrotitanium powder and concentrated sulfuric acid are usually subjected to an acid hydrolysis reaction in an acid hydrolysis reactor to produce titanyl sulfate, which is then hydrolyzed to form metatitanic acid, which is then calcined and crushed to obtain the titanium dioxide product. The advantage of the sulfuric acid process is that it can use cheap and easily available ilmenite and sulfuric acid as raw materials, the technology is relatively mature, the equipment is simple, and anti-corrosion materials are easy to solve.

[0003] In the process of preparing titanium dioxide powder by sulfuric acid method, the acidolysis tail gas is mainly water vapor, and takes away a small amount of acid mist, and produces a small amount of SO2. At present, the tail gas treatment of titanium dioxide production is mainly carried out by water washing and alkaline water washing. The acidolysis reaction of titanium dioxide powder by sulfuric acid method is divided into intermittent acidolysis and continuous acidolysis. In the process of intermittent acidolysis, the emission of acidolysis tail gas is unstable, the instantaneous emission is too large, and it is difficult to achieve stable emission standards after treatment. Therefore, in view of this, the inventor provides an acidolysis tail gas treatment device for titanium dioxide production to solve the above problems. Utility Model Content

[0004] The utility model aims to solve the problem in the traditional titanium dioxide production that the intermittent acidolysis tail gas emission is unstable, which makes it difficult to achieve stable emission of the acidolysis tail gas up to the standard.

[0005] In order to achieve the above-mentioned purpose, the basic scheme of the utility model provides an acid hydrolysis tail gas treatment device for titanium dioxide production, comprising:

[0006] The top of the inclined composite spraying pipeline is connected to the top of the acid decomposition reactor in the titanium dioxide production line, and a plurality of water washing nozzles are evenly arranged on the top of the composite spraying pipeline;

[0007] A diversion trough, connected to the bottom of the composite spraying pipeline, for gas-liquid separation;

[0008] A pressure tank, connected to the diversion tank;

[0009] An alkali washing tower is connected to the pressure tank and a throttle valve is provided between the pressure tank and the alkali washing tower, and a plurality of alkali washing nozzles are provided in the alkali washing tower;

[0010] The vent chimney is connected to the top of the alkali washing tower.

[0011] Furthermore, a riser is provided between the diverter trough and the pressure tank, one end of the riser extends vertically downward and communicates with the top of the diverter trough, and the other end of the riser is communicated with the side wall of the pressure tank.

[0012] Furthermore, a plurality of water washing nozzles are evenly arranged in the vertical section of the riser, and the direction of the water washing nozzles is opposite to the gas flow direction in the riser.

[0013] Furthermore, an activated carbon layer is provided at the top of the alkali washing tower, a filter layer is provided at the bottom of the alkali washing tower, and the alkali washing nozzles are located between the activated carbon layer and the filter layer.

[0014] Furthermore, the directions of the alkali washing nozzles are staggered along the top and bottom of the alkali washing tower.

[0015] Furthermore, a demister is provided on the top of the alkali washing tower, and a fan is provided between the demister and the venting chimney.

[0016] Furthermore, some of the alkali washing nozzles are connected to an external pipe that can supply seed crystal washing water into the alkali washing tower, and the remaining alkali washing nozzles are connected to an alkali solution circulation pipe that can supply diluted alkali solution into the alkali washing tower.

[0017] The principle and effect of this scheme are:

[0018] 1. Compared with the prior art, the utility model first passes the acidolysis tail gas into the re-spraying pipeline, uses the nozzle inside the re-spraying pipeline to wash and cool the acidolysis tail gas, and passes the acidolysis tail gas mixed with the cleaning liquid into the diverter trough for gas-liquid separation. The separated liquid is discharged into the sewage treatment station as production wastewater for neutralization treatment, and the separated gas enters the pressure tank for storage, and enters the alkali washing tower through the throttle valve for alkali washing, thereby absorbing the acid mist and other substances contained in the acidolysis tail gas, so that the emission of the acidolysis tail gas meets the emission standards, and the pressure tank and the throttle valve cooperate to temporarily store and relieve the pressure of the acidolysis tail gas, thereby avoiding the acidolysis tail gas from entering the alkali washing tower instantly and in large quantities, thereby improving the treatment effect of the acidolysis tail gas, and solving the problem that in the traditional titanium dioxide production, the intermittent acidolysis tail gas emission is unstable, which makes it difficult to achieve stable emission of the acidolysis tail gas up to the standard.

[0019] 2. In the utility model, a water washing nozzle is arranged in the vertical section of the riser, which can further remove the acid in the acidolysis tail gas, and the seed washing water and the diluted alkali solution are used to perform alkali washing on the acidolysis tail gas in turn, thereby further improving the treatment effect of the acidolysis tail gas. After the acidolysis tail gas after alkali washing reaches the pollutant emission standard, it is introduced into the vent chimney through the demister and the fan and discharged into the air. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A system diagram of an acid hydrolysis tail gas treatment device for titanium dioxide production proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0023] The reference numerals in the drawings of the specification include: acid hydrolysis reactor 1, re-spraying pipeline 2, diversion trough 3, alkali washing tower 4, fan 5, venting chimney 6, riser 7, pressure tank 8.

[0024] A device for treating tail gas from acid decomposition for titanium dioxide production, for example Figure 1 As shown: it includes a re-spraying pipeline 2, a diversion trough 3, a riser 7, a pressure tank 8, an alkali washing tower 4, an venting chimney 6, etc. which are arranged in sequence, as follows:

[0025] The re-spraying pipe 2 is obliquely arranged at one end of the acidolysis reactor 1 in the titanium dioxide production line, and the top of the re-spraying pipe 2 is interconnected with the top of the acidolysis reactor 1 in the titanium dioxide production line, so that the acidolysis exhaust gas generated in the acidolysis reactor 1 enters the re-spraying pipe 2, and a plurality of water washing nozzles are evenly arranged on the top of the re-spraying pipe 2 to clean and cool the acidolysis exhaust gas entering the re-spraying pipe 2, and to absorb part of the acid mist.

[0026] The diverter trough 3 is arranged below the bottom of the composite spraying pipeline 2. The acidolysis tail gas that has been cleaned and cooled enters the diverter trough 3, and undergoes gas-liquid separation in the diverter trough 3. The separated liquid is discharged into the sewage treatment station as production wastewater for neutralization and treatment, and the separated gas enters the riser 7. One end of the riser 7 is vertically downward and connected to the top of the diverter trough 3, and the other end of the riser 7 is connected to the side wall of the pressure tank 8. A number of water washing nozzles are also evenly arranged in the vertical section of the riser 7, and the direction of the water washing nozzle is opposite to the gas flow direction in the riser 7, that is, it is arranged downward, so that the water washing nozzle can also wash the acidolysis tail gas flowing in the riser 7 with water, thereby further removing the acid in the acidolysis tail gas.

[0027] The pressure tank 8 can be used for temporary storage of acidolysis tail gas. A throttle valve is provided between the pressure tank 8 and the alkali washing tower 4 for connection. The throttle valve can control the flow of the acidolysis tail gas entering the alkali washing tower 4, thereby preventing the acidolysis tail gas from entering the alkali washing tower 4 in large quantities instantaneously.

[0028] An activated carbon layer is arranged on the top of the alkali washing tower 4, a filter layer is arranged on the bottom of the alkali washing tower 4, a gas outlet is arranged on the top of the alkali washing tower 4, a liquid outlet is arranged on the bottom of the alkali washing tower 4, and a plurality of alkali washing nozzles are arranged between the activated carbon layer and the filter layer in the alkali washing tower 4, and the alkali washing nozzles respectively supply seed washing water and diluted alkali solution to the alkali washing tower 4, wherein the seed washing water is supplied by an outer pipe of the seed washing water, and the diluted alkali solution is circulated and supplied by an alkali solution circulation pipe and an alkali solution pump. Part of the acidic water at the bottom of the alkali washing tower 4 enters the sewage pipe and is sent to the sewage treatment station, and the acidolysis tail gas after alkali washing reaches the pollutant emission standard and flows out from the top of the alkali washing tower 4, and is introduced into the vent chimney 6 through the demister and the fan 5 and discharged into the air.

[0029] Compared with the prior art, the utility model first passes the acidolysis tail gas into the re-spraying pipe 2, uses the nozzle inside the re-spraying pipe 2 to wash and cool the acidolysis tail gas, and passes the acidolysis tail gas mixed with the cleaning liquid into the diverter trough 3 for gas-liquid separation, and the separated liquid is discharged into the sewage treatment station as production wastewater for neutralization treatment, and the separated gas enters the pressure tank 8 for storage, and enters the alkali washing tower 4 through the throttle valve for alkali washing, thereby adsorbing the acid mist and other substances contained in the acidolysis tail gas, so that the emission of the acidolysis tail gas meets the emission standards, and the pressure tank 8 cooperates with the throttle valve to temporarily store and relieve pressure on the acidolysis tail gas, thereby avoiding the acidolysis tail gas from entering the alkali washing tower 4 instantly and in large quantities, thereby improving the treatment effect of the acidolysis tail gas, and solving the problem of the difficulty in achieving stable emission of acidolysis tail gas in traditional titanium dioxide production due to unstable emission of intermittent acidolysis tail gas.

[0030] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A device for treating acidolysis tail gas for titanium dioxide production, characterized in that: include: The top of the inclined composite spraying pipeline is connected to the top of the acid decomposition reactor in the titanium dioxide production line, and a plurality of water washing nozzles are evenly arranged on the top of the composite spraying pipeline; A diversion trough, connected to the bottom of the composite spraying pipeline, for gas-liquid separation; A pressure tank, connected to the diversion tank; An alkali washing tower is connected to the pressure tank and a throttle valve is provided between the pressure tank and the alkali washing tower, and a plurality of alkali washing nozzles are provided in the alkali washing tower; The vent chimney is connected to the top of the alkali washing tower.

2. The acidolysis tail gas treatment device for titanium dioxide production according to claim 1, characterized in that: A riser is provided between the diverter trough and the pressure tank, one end of the riser extends vertically downward and communicates with the top of the diverter trough, and the other end of the riser is communicated with the side wall of the pressure tank.

3. The acidolysis tail gas treatment device for titanium dioxide production according to claim 2, characterized in that: A plurality of water washing nozzles are also evenly arranged in the vertical section of the riser, and the direction of the water washing nozzles is opposite to the gas flow direction in the riser.

4. The acidolysis tail gas treatment device for titanium dioxide production according to claim 1, characterized in that: An activated carbon layer is arranged on the top of the alkali washing tower, a filtering layer is arranged on the bottom of the alkali washing tower, and the alkali washing nozzles are all located between the activated carbon layer and the filtering layer.

5. The acidolysis tail gas treatment device for titanium dioxide production according to claim 4, characterized in that: The directions of the alkali washing nozzles are staggered along the top and bottom of the alkali washing tower.

6. The acidolysis tail gas treatment device for titanium dioxide production according to claim 1, characterized in that: A demister is also provided on the top of the alkali washing tower, and a fan is provided between the demister and the venting chimney.

7. The acidolysis tail gas treatment device for titanium dioxide production according to claim 1, characterized in that: Some of the alkali washing nozzles are connected to an external pipe that can supply seed crystal washing water into the alkali washing tower, and the remaining alkali washing nozzles are connected to an alkali liquid circulation pipe that can supply diluted alkali liquid into the alkali washing tower.

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