Acid-containing tail gas washing treatment system

Abstract

An acid-containing tail gas washing treatment system, comprising: a washing water storage tank (1), the washing water storage tank (1) being provided with a first washing water inlet (11), a second washing water inlet (12), and a washing water outlet; a first buffer kettle (2), the first buffer kettle (2) being provided with a first tail gas inlet (21), a washing liquid inlet, and a first liquid discharging port; a swirler (3), the swirler (3) being provided with a first swirler inlet, a second swirler inlet (31), and a swirler outlet; a main tower (4), communicated with the swirler outlet, an exhaust port being formed in the top of the main tower (4); and a regulation and control device (5), the regulation and control device (5) comprising a regulation and control unit, a gas acidity detector (51), and a first control valve (52). The acid-containing tail gas washing treatment system is provided with the regulation and control unit, the gas acidity detector (51), and the first control valve (52), the pH value of gas from the exhaust port of the main tower (4) can be measured, and the regulation and control unit compares the pH value of the gas with a preset range, controls the opening degree of the first control valve (52), and adjusts the adding flow rate of liquid alkali, so that the gas discharged from the exhaust port of the main tower (4) always meets the requirements, thereby achieving the objective of environmental protection.

Description

Acid-containing tail gas washing treatment system Technical Field

[0001] The present invention relates to the technical field of nickel ore processing, and in particular to a system for washing and treating acid-containing tail gas. Background Art

[0002] Laterite nickel ore is a loose, clay-like aggregate containing oxides of elements such as nickel, iron, magnesium, cobalt, silicon, and aluminum, formed through long-term geological processes such as weathering, leaching, dissemination, and alteration of nickel-bearing olivine bedrock in tropical or subtropical regions. The iron element is severely oxidized to a +3 valence state, giving it an overall reddish-brown appearance, hence the name laterite nickel ore. Unlike nickel sulfide ore, laterite nickel ore is a difficult-to-process oxide ore, making it difficult to effectively enrich nickel through beneficiation methods. Therefore, the current common treatment method for nickel extraction from laterite nickel ore is beneficiation, high-pressure acid leaching, and extraction.

[0003] Laterite nickel ore produces acidic tail gas during processing, which needs to be treated before it can be discharged. For example, patent CN201410495026.8 provides an acidic tail gas scrubbing device, comprising: a condenser, the condenser having a tail gas inlet, a cooling water inlet located above the tail gas inlet, a wash water outlet located below the tail gas inlet, and an air outlet located above the cooling water inlet; a venturi, the upper end of the venturi being the air inlet, the lower end of the venturi being the discharge port, the air inlet of the venturi being connected to the air outlet of the condenser; a water inlet pipe, the water inlet pipe being tangentially connected to the upper part of the venturi so that the wash water can enter the upper part of the venturi tangentially; a separator, the separator being provided with a feed inlet, a drain port, and an exhaust port; and a connecting elbow, the connecting elbow being connected to the lower end of the venturi, the connecting elbow being tangentially connected to the feed inlet of the separator.

[0004] However, there are the following problems: the acid content in the tail gas fluctuates, and the existing technology cannot adjust the flow rate of the alkali solution, which may result in too much or too little alkali solution, affecting the treatment effect of the acidic tail gas.

[0005] Summary of the Invention

[0006] In view of this, the present invention provides an acid tail gas washing treatment system, which can adjust the flow rate of alkali solution to ensure the acid tail gas treatment effect.

[0007] In order to achieve the above-mentioned object, the technical solution of the present invention is to provide an acid-containing tail gas washing treatment system, comprising: a wash water storage tank, the wash water storage tank being provided with a first wash water inlet for introducing alkaline wash water, a second wash water inlet for introducing liquid alkali, and a wash water outlet for discharging the wash liquid;

[0008] a first buffer kettle, the first buffer kettle being provided with a first exhaust gas inlet connected to the exhaust gas exhaust device, a washing liquid inlet connected to the washing water outlet, and a first liquid discharge port for discharging liquid;

[0009] a cyclone, the cyclone being provided with a first cyclone inlet connected to the liquid discharge port, a second cyclone inlet communicating with the wash water outlet, and a cyclone outlet for discharging liquid;

[0010] A main tower, the main tower is connected to the cyclone outlet, and an exhaust port is provided on the top of the main tower;

[0011] and a control device, the control device comprising a control unit, a gas acidity detector and a first control valve, the gas acidity detector being arranged at the exhaust port and being used to detect the acidity or alkalinity of the gas, the first control valve being arranged at the second wash water inlet, the control unit being electrically connected to the gas acidity detector and the first control valve, and the control unit being used to control the degree of opening of the first control valve according to the detection information of the gas acidity detector.

[0012] Furthermore, a wash water pump is provided at the wash water outlet of the wash water storage tank, and the wash water pump is connected to the wash water outlet, the first buffer kettle and the cyclone, and is used to pump the absorption liquid in the wash water storage tank to the first buffer kettle and the cyclone.

[0013] Furthermore, it includes a first wash water pump and a second wash water pump, the first wash water pump is connected to the wash water outlet, the first buffer tank and the cyclone; the second wash water pump is connected to the wash water outlet, the first buffer tank and the cyclone.

[0014] Furthermore, the cyclone includes a tank body, the first inlet of the cyclone is opened at the top of the tank body, the second inlet of the cyclone is opened on the side wall of the tank body and the air inlet direction of the second inlet of the cyclone is tangent to the tank body, and the cyclone outlet is opened at the bottom of the tank body.

[0015] Furthermore, the main tower forms an exhaust section, a swirl section and a liquid storage section in sequence from high to low, the swirl inlet is opened on the swirl section and the air intake direction of the swirl inlet is tangent to the swirl section, the exhaust port is arranged in the exhaust section, and the gas acidity detector is arranged on the inner wall of the exhaust section.

[0016] Furthermore, a plurality of interlaced partitions are provided in the exhaust portion.

[0017] Furthermore, the liquid storage part is connected to a discharge pipe, and the discharge pipe is used to discharge the liquid in the liquid storage part.

[0018] Furthermore, the liquid storage part is also connected to a reflux pipe, one end of the reflux pipe extends into the bottom of the liquid storage part, and the other end of the reflux pipe is connected to the discharge pipe. A reflux pump is provided on the reflux pipe for returning part of the liquid discharged from the discharge pipe to the bottom of the liquid storage part.

[0019] Furthermore, it includes a second buffer kettle, which is provided with a second tail gas inlet for introducing accidentally escaped gas, a liquid alkali inlet for introducing liquid alkali, and a second drain port for discharging liquid, and the second drain port is connected to the vortex inlet.

[0020] Furthermore, the control device also includes an airflow sensor and a second control valve. The airflow sensor is arranged at the second exhaust gas inlet to sense whether there is gas passing through the second exhaust gas inlet. The second control valve is arranged at the liquid alkali inlet. The control unit is electrically connected to the airflow sensor and the second control valve. The control unit is also used to control the opening and closing of the second control valve according to the sensing signal of the airflow sensor.

[0021] Furthermore, it also includes a liquid alkali filter box, which contains liquid alkali. An air inlet pipe is embedded in the liquid alkali filter box, one end of the air inlet pipe is passed under the liquid surface of the liquid alkali, and the other end is connected to the exhaust port. A gas discharge port is opened on the liquid alkali filter box.

[0022] Furthermore, the inner surface of the tank body is sprayed with a tungsten carbide wear-resistant coating.

[0023] Compared with the prior art, the acid-containing tail gas scrubbing treatment system and method provided by the present invention has the following beneficial effects:

[0024] Compared with the prior art, the present invention is provided with a control unit, a gas acidity detector, and a first control valve, which can detect the pH value of the gas at the exhaust port of the main tower. The control unit compares the pH value of the gas with a preset range, controls the opening degree of the first control valve, and adjusts the addition flow rate of liquid alkali, so that the gas discharged from the exhaust port of the main tower always meets the requirements, thereby achieving the purpose of environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic diagram of an acid-containing tail gas scrubbing treatment system provided by the present invention;

[0026] FIG2 is a schematic structural diagram of the cyclone in FIG1 ;

[0027] In the figure: 1-wash water storage tank, 11-first wash water inlet, 12-second wash water inlet, 13-wash water pump, 2-first buffer kettle, 21-first tail gas inlet, 3-cyclone, 31-cyclone second inlet, 32-tank body, 4-main tower, 41-exhaust section, 411-partition, 42-cyclone section, 43-liquid storage section, 431-discharge pipe, 432-reflux pipe, 433-reflux pump, 5-regulating device, 51-gas acidity detector, 52-first control valve, 53-air flow sensor, 54-second control valve, 6-second buffer kettle. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] Please refer to Figure 1. The present invention provides an acid-containing tail gas scrubbing treatment system, which includes: a wash water storage tank 1, a first buffer kettle 2, a cyclone 3, a main tower 4, and a control device 5. The wash water storage tank 1 is provided with a first wash water inlet 11 for introducing alkaline wash water, a second wash water inlet 12 for introducing liquid alkali, and a wash water outlet for discharging the wash liquid. The first buffer kettle 2 is provided with a first tail gas inlet 21 connected to the tail gas discharge device, a wash liquid inlet connected to the wash water outlet, and a first drain port for discharging the liquid; the cyclone 3 is provided with a first cyclone inlet connected to the drain port, a second cyclone inlet connected to the wash water outlet, and a first drain port for discharging the liquid. a second cyclone inlet 31 and a cyclone outlet for discharging liquid; the main tower 4 is connected to the cyclone outlet, and an exhaust port is provided on the top of the main tower 4; the control device 5 includes a control unit, a gas acidity detector 51 and a first control valve 52, the gas acidity detector 51 is provided at the exhaust port and is used to detect the acidity and alkalinity of the gas, the first control valve 52 is provided at the second wash water inlet 12, the control unit is electrically connected to the gas acidity detector 51 and the first control valve 52, and the control unit is used to control the opening degree of the first control valve 52 according to the detection information of the gas acidity detector 51.

[0030] Compared with the prior art, the present invention is provided with a control unit, a gas acidity detector 51, and a first control valve 52, which can detect the pH value of the gas at the exhaust port of the main tower 4. The control unit compares the pH value of the gas with a preset range, controls the opening degree of the first control valve 52, and adjusts the flow rate of liquid alkali addition so that the gas discharged from the exhaust port of the main tower 4 always meets the requirements, thereby achieving the purpose of environmental protection.

[0031] Specifically, the wash water storage tank 1 is used to store alkaline liquid, some of which comes from alkaline wastewater from the production process, and some of which comes from separately added liquid caustic soda. The second wash water inlet 12 for adding liquid caustic soda is provided because the alkalinity of the alkaline wastewater from the production process is unstable and may not be sufficient to scrub acidic gases. Therefore, the second wash water inlet 12 is provided to replenish the alkaline liquid so that the alkaline liquid in the wash water storage tank 1 can meet the needs of scrubbing acidic gases.

[0032] Specifically, a wash water pump 11 is provided at the wash water outlet of the wash water storage tank 1, and the wash water pump 11 is connected to the wash water outlet, the first buffer tank 2 and the cyclone 3, and is used to pump the absorption liquid in the wash water storage tank 1 to the first buffer tank 2 and the cyclone 3.

[0033] Furthermore, the system includes a first wash water pump and a second wash water pump. The first wash water pump is connected to the wash water outlet, the first buffer tank, and the cyclone. The second wash water pump is connected to the wash water outlet, the first buffer tank, and the cyclone. The first and second wash water pumps serve as backup for each other. When one pump needs to be shut down for maintenance, the other pump can be switched to ensure the operation of the acidic tail gas scrubbing treatment system.

[0034] Specifically, the first buffer kettle 2 is fed with the high-pressure kettle tail gas, high-temperature preheated tail gas, medium-temperature preheated tail gas, low-temperature preheated tail gas and flash sealing gas tail gas in the acid leaching process. The tail gas is mixed with the absorption liquid in the first buffer kettle 2 and then sent into the cyclone 3. An atomizing nozzle is provided at the inlet of the washing liquid, and the absorption liquid is in an atomized state when entering the first buffer kettle 2.

[0035] Referring to Figure 2 , the cyclone 3 comprises a tank 32. The first inlet is located at the top of the tank 32, and the second inlet is located on the sidewall of the tank 32. The second inlet's intake direction is tangential to the tank 32, and the cyclone outlet is located at the bottom of the tank 32. The absorption liquid enters the tank 32 tangentially through the second inlet, forming a vortex within the tank 32. This creates a negative pressure within the vortex. The gas buffered in the first buffer tank 2 is thoroughly mixed and absorbed in the central portion of the tank 32 due to the pressure differential. The processing capacity of the tank 32 is regulated by the flow rate at the second inlet. Because the exhaust gas is relatively hot, it also cools in the tank 32. Therefore, the cyclone 3 can both absorb the exhaust gas and cool it.

[0036] Furthermore, the inner surface of the tank body 32 is sprayed with a tungsten carbide wear-resistant coating, and the thickness of the tungsten carbide wear-resistant coating is 0.15 mm, which increases the wear resistance of the tank body 32 and helps to extend the service life of the cyclone 3.

[0037] Specifically, the main tower 4 is vertically arranged and sequentially forms an exhaust section 41, a swirl section 42, and a liquid storage section 43 from top to bottom. The swirl inlet is located on the swirl section, and the air intake direction of the swirl inlet is tangential to the swirl section. The exhaust port is located in the exhaust section 41, and the gas acidity detector 51 is located on the inner wall of the exhaust section 41. The swirl section 42 performs gas-liquid separation, allowing the scrubbed gas to enter the exhaust section 41 upward and the liquid to fall into the liquid storage section 43.

[0038] Furthermore, a plurality of interlaced partitions 411 are provided in the exhaust portion 41 . The partitions 411 can block the airflow and slow down the flow rate of the airflow, thereby facilitating detection by the gas acidity detector 51 .

[0039] Furthermore, the liquid storage portion 43 is connected to a discharge pipe 431 , and the discharge pipe 431 is used to discharge the liquid in the liquid storage portion 43 .

[0040] Furthermore, the liquid storage part 43 is also connected to a reflux pipe 432, one end of the reflux pipe 432 extends into the bottom of the liquid storage part 43, and the other end of the reflux pipe 432 is connected to the discharge pipe 431. A reflux pump 433 is provided on the reflux pipe 432, which is used to return part of the liquid discharged from the discharge pipe 431 to the bottom of the liquid storage part 43, so as to churn the liquid in the liquid storage part 43 and avoid the formation of particles and deposition.

[0041] Furthermore, considering that laterite nickel ore will be depressurized due to excessive pressure during processing, some acidic gas will escape, so the acidic tail gas washing treatment system also includes a second buffer kettle 6, which is provided with a second tail gas inlet for introducing unexpectedly escaped gas, a liquid alkali inlet for introducing liquid alkali, and a second liquid discharge port for discharging liquid, and the second liquid discharge port is connected to the swirl inlet; the unexpectedly escaped gas is mixed with the liquid alkali in the second buffer kettle 6 and then introduced into the main tower 4. The purpose of directly introducing liquid alkali into the second buffer kettle 6 is to directly treat the unexpectedly escaped gas. Because the unexpectedly escaped gas escapes without undergoing subsequent treatment steps, its acidity is relatively strong. The alkaline wastewater in the production process is relatively weak and cannot meet the neutralization requirements of the unexpectedly escaped gas. Therefore, in this embodiment, liquid alkali is directly introduced into the second buffer kettle 6 to treat the unexpectedly escaped gas.

[0042] Furthermore, considering that the generation of unexpected escaping gas is not constant, the control device 5 also includes an airflow sensor 53 and a second control valve 54. The airflow sensor 53 is located at the second tail gas inlet to sense whether gas is passing through the second tail gas inlet, and the second control valve 54 is located at the liquid caustic soda inlet. The control unit is electrically connected to the airflow sensor 53 and the second control valve 54, and is further configured to control the opening and closing of the second control valve 54 based on the sensing signal from the airflow sensor 53. When unexpected escaping gas is delivered to the second tail gas inlet, the control unit drives the second control valve 54 to open, allowing liquid caustic soda to flow into the second buffer kettle 6 to absorb acidic gases. When no unexpected escaping gas is generated, the control unit drives the second control valve 54 to close, stopping the supply of liquid caustic soda to avoid waste of liquid caustic soda.

[0043] Furthermore, the system includes a liquid caustic soda filter box containing liquid caustic soda. An air inlet pipe is embedded in the filter box, one end of which is inserted below the liquid caustic soda level and the other end is connected to the exhaust port. A gas discharge port is also provided in the filter box. The gas discharged from the main tower 4 is further washed with liquid caustic soda to ensure that the exhaust gas does not contain acidic gases.

[0044] During use, alkaline wastewater from the production process is first passed into the wash water storage tank 1 for storage to form an absorption liquid. The tail gas discharged from the production end and the absorption liquid are sequentially sent to the first buffer kettle 2, the cyclone 3, and the main tower 4 for absorption and separation. The accidentally escaped gas is mixed with liquid caustic soda in the second buffer kettle 6 and sent to the main tower 4 for absorption and separation. Non-acidic gas is discharged from the exhaust section 41, and the liquid that has absorbed the acidic gas falls into the liquid storage section 43. The discharge pipe 431 discharges the liquid in the liquid storage section 43 to the outside. The reflux pipe 432 and the reflux pump 433 return part of the liquid to the bottom of the liquid storage section 43 to cause the liquid to tumble and prevent particle deposition in the liquid. The gas acidity detector 51 in the exhaust section 41 detects the acidity of the gas. The control unit controls the opening degree of the first control valve 52 based on the detection information of the gas acidity detector 51 to adjust the flow rate of the liquid caustic soda so that the gas discharged from the exhaust port of the main tower 4 always meets the requirements, thereby achieving environmental protection purposes.

[0045] Compared with the prior art, the present invention has the following advantages:

[0046] Compared with the prior art, the present invention is provided with a control unit, a gas acidity detector, and a first control valve, which can detect the pH value of the gas at the exhaust port of the main tower. The control unit compares the pH value of the gas with a preset range, controls the opening degree of the first control valve, and adjusts the addition flow rate of liquid alkali, so that the gas discharged from the exhaust port of the main tower always meets the requirements, thereby achieving the purpose of environmental protection.

[0047] The above-described specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the present invention.

Claims

1. A system for washing and treating acid-containing tail gas, characterized in that: include: A washing water storage box, wherein the washing water storage box is provided with a first washing water inlet for introducing alkaline washing water, a second washing water inlet for introducing liquid alkali, and a washing water outlet for discharging washing liquid; a first buffer kettle, wherein the first buffer kettle is provided with a first tail gas inlet connected to the tail gas discharge device, a washing liquid inlet connected to the washing water outlet, and a first liquid discharge port for discharging liquid; A cyclone, wherein the cyclone is provided with a first cyclone inlet connected to the liquid discharge port, a second cyclone inlet connected to the wash water outlet, and a cyclone outlet for discharging liquid; A main tower, the main tower is connected to the outlet of the cyclone, and an exhaust port is provided at the top of the main tower; and a regulating device, the regulating device comprising a regulating unit, a gas acidity detector and a first control valve, the gas acidity detector being arranged at the exhaust port and used for detecting the acidity or alkalinity of the gas, the first control valve being arranged at the second wash water inlet, the regulating unit being electrically connected to the gas acidity detector and the first control valve, and the regulating unit being used for controlling the opening degree of the first control valve according to the detection information of the gas acidity detector.

2. The acid-containing tail gas scrubbing treatment system according to claim 1, characterized in that: A wash water pump is provided at the wash water outlet of the wash water storage tank. The wash water pump is connected to the wash water outlet, the first buffer kettle and the cyclone, and is used to pump the absorption liquid in the wash water storage tank to the first buffer kettle and the cyclone.

3. The acid-containing tail gas scrubbing treatment system according to claim 2, characterized in that: It comprises a first washing water pump and a second washing water pump, wherein the first washing water pump is connected to the washing water outlet, the first buffer kettle and the cyclone; and the second washing water pump is connected to the washing water outlet, the first buffer kettle and the cyclone.

4. The acid-containing tail gas scrubbing treatment system according to claim 1, characterized in that: The cyclone comprises a tank body, the first inlet of the cyclone is opened at the top of the tank body, the second inlet of the cyclone is opened on the side wall of the tank body and the air inlet direction of the second inlet of the cyclone is tangent to the tank body, and the cyclone outlet is opened at the bottom of the tank body.

5. The acid-containing tail gas scrubbing treatment system according to claim 1, characterized in that: The main tower forms an exhaust section, a swirl section and a liquid storage section in sequence from high to low, a swirl inlet is opened on the swirl section and the air intake direction of the swirl inlet is tangent to the swirl section, the exhaust port is arranged in the exhaust section, and the gas acidity detector is arranged on the inner wall of the exhaust section.

6. The acid-containing tail gas scrubbing treatment system according to claim 5, characterized in that: A plurality of interlaced partitions are arranged in the exhaust part.

7. The acid-containing tail gas scrubbing treatment system according to claim 5, characterized in that: The liquid storage part is connected to a discharge pipe, and the discharge pipe is used to discharge the liquid in the liquid storage part.

8. The acid-containing tail gas scrubbing treatment system according to claim 7, characterized in that: The liquid storage part is also connected to a reflux pipe, one end of which extends into the bottom of the liquid storage part, and the other end of the reflux pipe is connected to the discharge pipe. The reflux pipe is provided with a reflux pump for returning part of the liquid discharged from the discharge pipe to the bottom of the liquid storage part.

9. The acid-containing tail gas scrubbing treatment system according to claim 1, characterized in that: It also includes a second buffer kettle, which is provided with a second tail gas inlet for introducing accidentally escaped gas, a liquid alkali inlet for introducing liquid alkali and a second liquid discharge port for discharging liquid, and the second liquid discharge port is connected to the vortex inlet.

10. The acid-containing tail gas scrubbing treatment system according to claim 9, characterized in that: The control device also includes an airflow sensor and a second control valve. The airflow sensor is arranged at the second exhaust gas inlet to sense whether there is gas passing through the second exhaust gas inlet. The second control valve is arranged at the liquid alkali inlet. The control unit is electrically connected to the airflow sensor and the second control valve. The control unit is also used to control the opening and closing of the second control valve according to the sensing signal of the airflow sensor.

11. The acid-containing tail gas scrubbing treatment system according to claim 1, characterized in that: It also includes a liquid alkali filter box, which contains liquid alkali. An air inlet pipe is embedded in the liquid alkali filter box. One end of the air inlet pipe is passed under the liquid surface of the liquid alkali, and the other end is connected to the exhaust port. A gas exhaust port is opened on the liquid alkali filter box.

12. The acid-containing tail gas scrubbing treatment system according to claim 4, characterized in that: The inner surface of the tank body is sprayed with a tungsten carbide wear-resistant coating.

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