Strong oxidation wet washing thallium removal device

Abstract

A strong oxidation wet washing thallium removal device comprises a dust remover, an ozone reactor and a thallium washing tower, one end of the dust remover is connected with a waste gas outlet, the other end of the dust remover is connected with the ozone reactor, the middle position of the thallium washing tower is connected with the ozone reactor, and the dust remover is provided with a dust removal structure capable of reducing dust in smoke. The ozone reactor is provided with an ozone inlet capable of mixing nitric oxide in the flue gas with ozone to generate oxidation reaction to generate nitric oxide, the thallium washing tower is provided with a clear water spraying device, so that the nitric oxide is mixed with water to form nitric acid, thallium in the flue gas is in contact with the water to form thallium ions, and the thallium ions are combined with other anions to form thallium salt. The device can solve the headache problem of thallium ion discharge in the lithium battery industry, and also solves the problem of denitration catalyst poisoning at the same time, so that multiple purposes are achieved at one stroke.

Description

Technical Field

[0001] The utility model belongs to the field of waste gas treatment, and in particular relates to a strong oxidation wet scrubbing thallium removal device. Background Art

[0002] The lithium used to prepare lithium batteries is basically prepared from lithium carbonate. Lithium carbonate is prepared from lithium ores such as spodumene and petalite through high-temperature heating, acid-base treatment, precipitation, drying and other steps. Among them, after high-temperature heating, the lithium ore reacts with carbonate to produce products such as lithium carbonate and silicate. Then, lithium carbonate is separated from the reaction solution through acid-base treatment, precipitation, drying and other steps to obtain the final product. During the high-temperature heating process of the rotary roasting kiln, high-temperature flue gas is generated. The flue gas contains harmful substances such as NOx, SO2, and Ti (thallium), which need to be removed by tail gas treatment.

[0003] At present, the basic treatment method for lithium carbonate kiln flue gas is: rotary kiln roasting flue gas + cyclone dust collector + high-temperature dust and nitrogen integrated removal system + air preheater + fan + wet desulfurization system + chimney. This method can remove harmful substances such as NOx, SO2, and dust, but it cannot remove thallium in the flue gas, and thallium will also adhere to the surface of the catalyst, causing the catalyst to lose activity and affecting the denitrification efficiency. Utility Model Content

[0004] In view of the above-mentioned prior art, the purpose of the utility model is to provide a strong oxidation wet scrubbing thallium removal device for removing thallium.

[0005] The technical solution of the utility model is implemented as follows: a strong oxidation wet scrubbing thallium removal device comprises a dust collector, an ozone reactor and a thallium scrubber, one end of the dust collector is connected to the exhaust gas outlet, the other end of the dust collector is connected to the ozone reactor, the middle position of the thallium scrubber is connected to the ozone reactor, the dust collector is provided with a dust removal structure capable of reducing dust in the flue gas, the ozone reactor is provided with an ozone air inlet capable of mixing nitrogen monoxide in the flue gas with ozone to generate an oxidation reaction to generate nitrogen oxides, the thallium scrubber is provided with a clean water spraying device to mix the nitrogen oxides with water to form nitric acid, the thallium in the flue gas contacts with water to form thallium ions, and the thallium ions combine with other anions to form thallium salts.

[0006] The beneficial effect of such a design is that the device can remove thallium from flue gas. The thallium in flue gas may exist in the form of thallium salt or in the form of a single substance and may not be easily soluble in water. However, the use of nitrogen oxides in flue gas to generate nitric acid can make various thallium elements more easily generate water-soluble thallium nitrate, making the removal of thallium in flue gas more thorough. The device can solve the thallium ion emission problem that has been a headache for the lithium battery industry, and also solve the problem of denitrification catalyst poisoning, which can be said to kill two birds with one stone.

[0007] Furthermore, the dust collector is a bag dust collector, which can use the filtering effect of fiber fabric to filter dust-containing gas. When the dust-containing gas enters the bag dust collector, the dust with large particles and high specific gravity settles down due to gravity and falls into the ash hopper. When the gas containing finer dust passes through the filter material, the dust is retained, so that the gas is purified to avoid affecting other chemical reactions.

[0008] Furthermore, the upper end of the thallium washing tower is connected to the acid washing tower, and the acid washing tower is provided with an alkaline liquid spray device that can react with the acid gas. Since the flue gas may contain acid gases such as sulfur dioxide, the use of the alkaline liquid spray device can reduce harmful gases in the flue gas through chemical reactions.

[0009] Furthermore, a liquid storage tank is provided at the lower end of the thallium washing tower, and the liquid storage tank is provided with a circulating spray pipeline, so that the circulating water is more water-saving, and the nitric acid contained in the water can make the thallium element more easily soluble in the water.

[0010] Furthermore, the liquid storage tank is provided with a pH detection device or an ion concentration detection device, which can use the principle of conductivity to detect the ion concentration in the water. When the ion concentration reaches a certain range, a liquid pump can be used to pump out the liquid for concentrated crystallization or other methods can be used to extract the thallium element for recycling.

[0011] Furthermore, an alkali solution pool is provided at the lower end of the acid washing tower, and the alkali solution pool is provided with a circulation pipeline to sequentially use the alkali solution, thereby improving the utilization rate of the alkali solution and reducing the use cost.

[0012] Furthermore, a plurality of spoilers are provided below the clean water spray device, and the spoilers can form turbulence to allow the flue gas to fully contact with the liquid, thereby making the gas purification more complete.

[0013] Furthermore, a centrifugal turbine is provided above the clean water spray device, and the centrifugal turbine can use centrifugal force to blow the larger mass components in the flue gas to the inner wall of the thallium washing tower. A spray structure can be provided on the inner wall to further dissolve some particles in the flue gas.

[0014] Furthermore, a baffle is provided above the centrifugal turbine so that the gas can only flow from the periphery of the turbine, so that part of the flue gas with a larger mass circulates downward, and the flue gas with a smaller mass flows upward from the periphery, and harmful particles in the flue gas can be more fully dissolved.

[0015] Furthermore, a water absorbing layer is provided on the inner wall of the thallium washing tower, and the water absorbing layer can absorb a certain amount of moisture so that some particles of the flue gas can be dissolved in water after being blown to the inner wall of the thallium washing tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The utility model is a schematic diagram of a strong oxidation wet scrubbing thallium removal device. DETAILED DESCRIPTION

[0017] As required, detailed embodiments of the present invention are disclosed herein, but it should be understood that the disclosed embodiments are only exemplary of the present invention, and the present invention may be implemented in different and alternative forms. The drawings are not necessarily drawn to scale, and certain features may be exaggerated or reduced to show the details of specific components. Therefore, the specific structural and functional details disclosed herein should not be understood as having a limiting meaning, but only as a representative basis to teach those skilled in the art to adopt the present invention differently. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, a strong oxidation wet scrubbing thallium removal device comprises a dust collector 1, an ozone reactor 2 and a thallium scrubber 3. One end of the dust collector 1 is connected to the exhaust gas outlet, the other end of the dust collector 1 is connected to the ozone reactor 2, and the middle position of the thallium scrubber 3 is connected to the ozone reactor 2. The dust collector 1 is provided with a dust removal structure to reduce dust in the flue gas. The ozone reactor 2 is provided with an ozone inlet to mix nitrogen monoxide in the flue gas with ozone to generate nitrogen oxides by oxidation reaction. The thallium scrubber 3 is provided with a clean water spray device to mix nitrogen oxides with water to form nitric acid. The thallium in the flue gas contacts with water to form thallium ions, and the thallium ions combine with other anions to form thallium salts. The dust collector 1 is a bag dust collector 1. The upper end of the thallium scrubber 3 is connected to the acid scrubber 4, and the acid scrubber 4 is provided with an alkaline liquid spray device to react with acidic gas. The lower end of the thallium scrubber 3 is provided with a liquid reservoir 9, and the liquid reservoir 9 is provided with a circulating spray pipeline. The liquid storage tank 9 is provided with a pH detection device or an ion concentration detection device. An alkali liquid pool 10 is provided at the lower end of the acid washing tower 4, and the alkali liquid pool 10 is provided with a circulation pipeline to sequentially use the alkali liquid. A plurality of spoilers 8 are provided below the clean water spray device. A centrifugal turbine 6 is provided above the clean water spray device. A baffle 11 is provided above the centrifugal turbine 6 so that the gas can only flow from the periphery of the centrifugal turbine 6, the gas with a smaller density will flow upward, and the gas with a larger density will flow downward to form a vortex circulation flow, and contact the inner wall of the thallium washing tower 3 for many times, and the inner wall of the thallium washing tower 3 is provided with a water absorption layer 7. The water absorption layer 7 is a corrosion-resistant plastic mesh or a sponge is directly used.

[0019] The flue gas temperature is more suitable at 140℃. The lithium carbonate kiln will be equipped with an air preheater. If used in other kilns, the temperature should also be controlled at around 140℃. Too high or too low will affect the subsequent chemical reaction effect. The flue gas first enters the bag filter 1 for dust removal, reducing the dust to 10mg / Nm 3 Then it enters the ozone reactor 2 to oxidize the NO in the flue gas into N2O5. The chemical reaction is as follows:

[0020] NO +O3=NO2+ O2

[0021] 2NO2+O3=N2O5+ O2

[0022] N2O5 enters the thallium scrubber 3, where thallium ions and N2O5 are dissolved in water at the same time and react to generate thallium nitrate (TINO3). The chemical reaction is as follows:

[0023] N2O5+H2O=2HNO3

[0024] HNO3+TI +1 = H +1 +TINO3

[0025] The thallium washing tower 3 adopts clean water circulation spray washing, and keeps replenishing clean water or recycling the water in the liquid storage tank 9. After the generated thallium nitrate salt reaches a certain concentration, it is pumped out with a liquid pump for concentrated crystallization, and metallic thallium can also be refined. In this way, the washing of thallium and the removal of NOx are completed in the thallium washing tower at the same time.

Claims

1. A strong oxidation wet scrubbing thallium removal device, comprising a dust collector (1), an ozone reactor (2) and a thallium scrubber (3), wherein one end of the dust collector (1) is connected to an exhaust gas outlet, the other end of the dust collector (1) is connected to the ozone reactor (2), and the middle position of the thallium scrubber (3) is connected to the ozone reactor (2), the dust collector (1) is provided with a dust removal structure capable of reducing dust in flue gas, the ozone reactor (2) is provided with an ozone inlet capable of mixing nitrogen monoxide in the flue gas with ozone to generate an oxidation reaction to generate nitrogen oxides, the thallium scrubber (3) is provided with a clean water spraying device to mix nitrogen oxides with water to form nitric acid, thallium in the flue gas contacts with water to form thallium ions, and the thallium ions combine with other anions to form thallium salts.

2. The strong oxidation wet scrubbing thallium removal device according to claim 1 is characterized in that: The dust collector (1) is a bag dust collector (1).

3. The strong oxidation wet scrubbing thallium removal device according to claim 1 is characterized in that: The upper end of the thallium washing tower (3) is connected to the acid washing tower (4), and the acid washing tower (4) is provided with an alkaline liquid spraying device capable of reacting with the acid gas.

4. The strong oxidation wet scrubbing thallium removal device according to claim 1 is characterized in that: A liquid storage tank (9) is provided at the lower end of the thallium washing tower (3), and a circulating spray pipeline is provided in the liquid storage tank (9).

5. The strong oxidation wet scrubbing thallium removal device according to claim 4 is characterized in that: The liquid storage tank (9) is provided with a pH detection device or an ion concentration detection device.

6. The strong oxidation wet scrubbing thallium removal device according to claim 3 is characterized in that: An alkali solution pool (10) is provided at the lower end of the acid washing tower (4), and the alkali solution pool (10) is provided with a circulation pipeline for sequentially using the alkali solution.

7. The strong oxidation wet scrubbing thallium removal device according to claim 1 is characterized in that: A plurality of spoilers (8) are provided below the clean water spray device.

8. The strong oxidation wet scrubbing thallium removal device according to claim 1 is characterized in that: A centrifugal turbine (6) is provided above the clean water spraying device.

9. The strong oxidation wet scrubbing thallium removal device according to claim 8, characterized in that: A baffle (11) is provided above the centrifugal turbine (6) so that the gas can only flow from the periphery of the centrifugal turbine (6).

10. The strong oxidation wet scrubbing thallium removal device according to claim 1, characterized in that: The inner wall of the thallium washing tower (3) is provided with a water absorption layer (7).

Images