A liquid phase vaporization detoxification method suitable for blast furnace gas hydrolysis desulfurization process

Abstract

The present invention discloses a liquid phase vaporization detoxification method suitable for blast furnace gas hydrolysis desulfurization process, which utilizes a liquid organic amine solution to be vaporized in a dedicated vaporization device, and the vaporized gas reacts with the blast furnace gas in the gas phase. The process device is installed on the pipeline connecting the gravity dust collector and the bag dust collector; the liquid phase detoxification liquid is vaporized into a gas phase at high temperature and then reacts with HCl, HF, HCN, HNO3, SO3 in the blast furnace gas. 2‑ 、SO4 2‑ The inorganic acid radicals react with the ions, generating stable chlorides and salts that adhere to the blast furnace gas dust and are collected in a bag filter before being discharged. The method of the present invention achieves an acidic poison removal rate exceeding 90%, thereby protecting the hydrolysis catalyst from poisoning and deactivation, significantly extending its service life. This process requires minimal initial investment and occupies a small footprint. Its skid-mounted design facilitates installation and transportation, and the system utilizes integrated PLC control for simple operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of front-end purification and desulfurization of blast furnace gas in the steel industry, and in particular relates to a process device and method for detoxifying blast furnace gas in the ironmaking industry. Background Art

[0002] Blast furnace gas is commonly used as fuel for hot blast furnaces, regenerative furnaces, and boilers, and is discharged directly after combustion. Because blast furnace gas contains acidic substances such as sulfides and chlorides, direct emission after combustion can result in excessive sulfur dioxide levels in the flue gas. To meet emerging environmental protection requirements, steel companies and environmental protection companies are implementing refined desulfurization of blast furnace gas at its source.

[0003] Since the sulfides in blast furnace gas are mainly COS and H2S, hydrogen sulfide can be removed by dry desulfurization agents or wet desulfurization, but COS can only be hydrolyzed into H2S by catalytic hydrolysis and then removed. Therefore, the existing front-end desulfurization of blast furnace gas requires hydrolysis catalytic conversion. The active center of the hydrolysis catalyst is an alkaline center. Blast furnace gas contains a large amount of strong acidic substances such as hydrogen chloride, sulfate, sulfite, nitrate, hydrocyanic acid, and hydrofluoric acid. Therefore, these poisons need to be removed by a protective agent. The existing methods of water washing or alkali spraying and the protective agent in the dechlorination protection reactor can only remove a single chloride in the gas. In addition, due to the influence of CO2, the chlorine capacity is small and it is easy to agglomerate. As a result, the hydrolysis catalyst can only operate for a few months before being poisoned and deactivated, and the hydrolysis agent has to be replaced, resulting in high operating costs and frequent catalyst replacement in the front-end fine desulfurization process.

[0004] Patent CN111378801A discloses a method and apparatus for removing hydrogen chloride from blast furnace gas pipelines by spraying powder. Patent CN114606026A discloses a method for simultaneously desulfurizing and dechlorinating blast furnace gas. Both methods employ a method of converting powder into a solid and spraying it into the blast furnace gas pipeline. The powders used are sodium carbonate, sodium bicarbonate, and the like. This involves a gas-solid reaction with a slow reaction rate. A large amount of powder is required to remove chlorine from the blast furnace gas. Furthermore, both methods are unable to remove other acidic poisons from the blast furnace gas.

[0005] Patent CN114292673A discloses a method and apparatus for dechlorination of blast furnace gas by wet full evaporation. This process requires a spray pump for pressurized dechlorination. The atomized liquid formed after spraying is dispersed in the blast furnace gas, which is affected by the gas-liquid distribution. Furthermore, the dechlorination liquid is a sodium carbonate solution, and the solid matter formed by vaporization in the blast furnace gas reacts with the chlorine in the blast furnace gas. Due to the low solubility of sodium carbonate or ammonium bicarbonate, they easily clog the nozzle at high temperatures. After evaporation, the reaction remains essentially a gas-solid reaction, resulting in high dosage, low removal efficiency, and inability to remove other acidic poisons. As is well known, the rates of both gas-liquid and gas-solid reactions are lower than those of gas-gas reactions. When the injection amount is small, both reactions result in insufficient reaction and poor removal efficiency. Summary of the Invention

[0006] Based on the above problems, in order to solve the problems of short service life and rapid activity decline of organic sulfur hydrolysis catalysts in the ultra-low emission process of blast furnace gas, combined with the characteristics of large gas volume, complex components and high impurity content of blast furnace gas, the use of traditional liquid spray and dry dechlorination agents requires additional reactors and has problems such as short replacement time, increased system pressure difference, and single removal of poisons. The present invention provides a method for removing acidic poisons in the gas by spraying vaporized organic amine gas into a pipeline after gravity dust removal through a gas-gas homogeneous reaction. The method is a liquid phase vaporization detoxification method suitable for the blast furnace gas hydrolysis desulfurization process.

[0007] This is achieved specifically through the following technical solutions:

[0008] A process device for liquid-phase vaporization detoxification suitable for hydrolysis desulfurization of blast furnace gas comprises: existing equipment blast furnace, gravity dust collector, bag dust collector, protection reactor, hydrolysis reactor and pipelines connecting the various components. A liquid-phase vaporization detoxification device is installed on the pipeline after the existing gravity dust collector and before the bag dust collector, thus constituting the process device for liquid-phase vaporization detoxification of blast furnace gas desulfurization of the present invention. The device mainly comprises: a solution buffer tank, a solution delivery pump, a vaporizer, an ejector, and pipelines connecting the various components and a control system.

[0009] The liquid-phase vaporization detoxification device for blast furnace gas hydrolysis and desulfurization is used to vaporize the liquid-phase detoxification liquid and then spray it into the blast furnace gas pipeline for detoxification reaction, thereby achieving gas-phase removal of chlorides and other strongly acidic substances; a liquid-phase vaporization detoxification method suitable for blast furnace gas hydrolysis and desulfurization process, the method comprising the following steps:

[0010] (1) A liquid phase detoxification liquid suitable for a liquid phase vaporization detoxification method for hydrolysis desulfurization of blast furnace gas, wherein the mass percentages of the raw materials used are as follows, with the sum of the mass percentages being 100%.

[0011] Organic amine 50~95;

[0012] Antioxidant 0.5~5;

[0013] Additives 1~10;

[0014] The remainder is demineralized water;

[0015] The preparation method is as follows: organic amine is first added to desalted water, and then antioxidant and stabilizer are added in sequence, and then stirred to form a uniform system, and finally a stable liquid phase detoxification solution is obtained.

[0016] (2) The liquid phase detoxified liquid from step (1) is transported to a solution buffer tank via a ton barrel or tank truck, and a certain liquid level is maintained in the buffer tank; the liquid enters the solution delivery pump through the discharge valve at the bottom of the buffer tank, and enters the vaporizer after being pressurized;

[0017] (3) After the solution in step (2) is heated in the vaporizer, the liquid phase detoxification liquid is completely vaporized in the vaporizer, and the vaporized gas is extracted from the top of the vaporizer through a wire mesh demister and then transferred to step (4);

[0018] (4) The gas phase of step (3) is transported to the blast furnace gas pipeline through an injection pipe and an injector after the flow rate is adjusted by a regulating valve. The injector is arranged in the pipeline after the gravity dust collector and before the bag dust collector;

[0019] (5) Gas phase components and HCl, HF, HCN, HNO3, SO3 in blast furnace gas 2- 、SO4 2- The inorganic acid radical ions react to generate stable chlorides and salts that adhere to the blast furnace gas dust, are captured by the bag filter, and are then discharged through the lower dust collector of the bag filter.

[0020] In the step (1), the organic amine is one or more of tert-butylamine, sec-butylamine, isobutylamine, n-hexylamine, ethanolamine, and N,N-dimethylethanolamine; the antioxidant is one or more of hydroquinone, resorcinol, and catechol; the auxiliary agent is one or more of methanol, ethanol, and isopropanol; the solution can be completely vaporized into a gas phase within 130° C., and the solution pH is greater than 10.

[0021] In the step (2), the solution delivery pump adopts a variable frequency pump to control the solution delivery volume.

[0022] In the step (3), a heater is provided in the vaporizer, and the temperature and pressure in the vaporizer are controlled by the heater. The pressure in the vaporizer is 0.4-0.6 MPa, the temperature is 130-165°C, and the liquid level is 60-80%. The liquid level in the vaporizer is interlocked with the solution delivery pump in step (2). When the liquid level in the vaporizer is lower than the low liquid level line, the solution delivery pump automatically starts. When the liquid level in the vaporizer is higher than the high liquid level, the solution delivery pump automatically stops. The vaporizer heater is interlocked with the liquid level of the vaporizer. When the liquid level gauge is lower than the lowest liquid level line, the vaporizer heater is turned off. The vaporizer and the pressure in the vaporizer are feedback-regulated. The material of the vaporizer is 316L.

[0023] In the step (4), two or three groups of injectors are provided, and each group of injectors is uniformly provided with 10 to 20 small holes of φ2 to φ5 mm. A check valve and a shut-off valve are provided on the injection pipe to prevent blast furnace gas from flowing back into the injection pipe and the vaporizer; the shut-off valve is interlocked with the vaporizer pressure setting, and when the pressure in the vaporizer is lower than the pressure in the blast furnace gas pipe, the shut-off valve is closed; the injection pipe requires steam or electric heating, and the heating temperature is greater than 130°C.

[0024] In the step (5), the blast furnace gas flow rate is 100,000~400,000 Nm 3 / h, pressure 0.15~0.2MPa, temperature 130~150℃, linear speed 15~30m / s, dust content less than 10mg / m 3 The content of gas phase after the liquid phase detoxification liquid is vaporized in blast furnace gas is 50~200mg / m 3 The injection amount is adjusted in real time according to the concentration of acidic poisons such as hydrogen chloride at the gas outlet.

[0025] Advantages of the present invention:

[0026] 1. The detoxification solution is a liquid organic amine solution, which can be completely vaporized into alkaline gas components within 130 ° C. The gas components react with the acidic substances in the blast furnace gas. The reaction time is fast, and the products after the reaction are stable chlorides and salts. They have strong adsorption properties and can be directly adsorbed on the blast furnace dust. Then, they are captured and removed by the original bag dust collector, thereby achieving the purpose of removing poisons.

[0027] 2. The detoxification adopts gas-gas homogeneous reaction. The gas-gas reaction is better than gas-liquid and gas-solid reaction. The removal rate of acidic poisons is greater than 90%. While removing chlorides, it can also remove strong acidic substances such as sulfate, sulfite, nitrate, and hydrocyanate, thereby protecting the hydrolysis catalyst from poisoning and inactivation.

[0028] 3. The detoxification reaction mechanism is as follows:

[0029] R-NH2+HCL=R-NH3Cl

[0030] R-NH2+HF=R-NH3F

[0031] R-NH2+HCN=R-NH3CN

[0032] R-NH2+HNO3=R-NH3NO3

[0033] 2R-NH2+H2SO3=(R-NH3)2SO3

[0034] 2R-NH2+H2SO4=(R-NH3)2SO4

[0035] After the organic amine solution is vaporized, it reacts with the acidic substances in the blast furnace gas, and the generated stable organic amine salt substances crystallize and precipitate, and then are captured by the bag dust collector of the blast furnace gas and discharged, thereby achieving the effect of removing acidic poisons. Compared with the reaction after the vaporization of ordinary ammonia solution, the ammonium chloride, ammonium nitrate, ammonium sulfate, etc. generated by the reaction of ammonia water vaporization with blast furnace gas are easily decomposed under working conditions above 100°C and cannot form solid ammonium salt substances, resulting in the inability to capture them by the bag dust collector, poor removal effect, and inability to remove most acidic substances; in view of the easy oxidation characteristics of organic amines, antioxidants are added to the organic amine solution to increase the stability of the organic amine solution. At the same time, in order to increase the solubility of the antioxidant in the organic amine solution, alcohol cosolvents are added.

[0036] 4. The detoxification process device adopts skid-mounted integration, with low one-time investment, saving floor space, easy installation and transportation. The system adopts PLC integrated control, simple operation, and no special supervision is required.

[0037] 5. The liquid-phase vaporization detoxification method used in the present invention is suitable for hydrolysis and desulfurization of blast furnace gas. It has strong adaptability to blast furnace operating conditions, does not increase system resistance, and can adjust the injection amount of detoxification liquid at any time according to the gas volume and acidic substances in the blast furnace gas. In addition, the daily amount of detoxification liquid used is small, the cost is low, and the additional cost is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flowchart of the existing blast furnace gas dry dechlorination process;

[0039] Among them: 1- blast furnace, 2- gravity dust collector, 3- bag dust collector, 4- protection reactor, 5- hydrolysis reactor.

[0040] Figure 2 The present invention provides a flow chart of a liquid phase vaporization detoxification method suitable for blast furnace gas hydrolysis desulfurization process:

[0041] Among them: 1- blast furnace, 2- gravity dust collector, 3- bag dust collector, 4- protection reactor, 5- hydrolysis reactor, 6- solution buffer tank, 7- solution delivery pump, 8- vaporizer, 9- ejector. DETAILED DESCRIPTION

[0042] The following combination Figure 1 、 Figure 2 The present invention is further described with reference to the accompanying drawings and examples, but the present invention is not limited to the examples.

[0043] A steel plant has a blast furnace gas hydrolysis fine desulfurization device. The process before TRT is as shown in the attached figure. Figure 1 As shown: the blast furnace gas from the blast furnace 1 passes through the gravity dust collector 2 for coarse dust removal and then enters the bag dust collector 3, thereby removing most of the dust in the blast furnace gas. In order to purify the sulfides in the blast furnace gas, the bag dust collector 3 is connected to the protection reactor 4 and the hydrolysis reactor 5 in sequence. The blast furnace gas after hydrolysis is removed by TRT, thereby achieving the purpose of fine desulfurization.

[0044] The blast furnace gas condition after gravity dust collector 2 is: flow rate of 100,000~400,000 Nm 3 / h, temperature 130~150℃, pressure 0.15~0.2MPa, linear speed 15~30m / s, dust content less than 10mg / m 3 The hydrolysis catalyst in the hydrolysis desulfurization unit was poisoned and deactivated after only two months of operation.

[0045] In order to extend the service life of the hydrolysis catalyst, a liquid phase vaporization and detoxification device for blast furnace gas hydrolysis desulfurization is added to the pipeline connecting the gravity dust collector 2 and the bag dust collector 3. The specific process is as follows:

[0046] (1) First, add the liquid detoxification liquid into the solution buffer tank 6 through a ton barrel or tank truck to maintain a certain liquid level.

[0047] (2) The solution enters the solution delivery pump 7 through the discharge valve at the bottom of the solution buffer tank 6. The variable frequency control is adopted, and the variable frequency value of the solution delivery pump 7 is controlled by the liquid level in the vaporizer 8. The specific control method is: the solution delivery pump 7 enters the vaporizer 8 after being pressurized. When the liquid level in the vaporizer 8 is higher than the set liquid level, the variable frequency hertz decreases, thereby reducing the speed of the solution delivery pump 7 and reducing the solution delivery; when the liquid level in the vaporizer 8 is lower than the set liquid level, the variable frequency hertz increases, thereby increasing the speed of the solution delivery pump 7 and increasing the solution delivery. The liquid level in the vaporizer 8 can be stably adjusted by PLC adjustment.

[0048] (3) The solution of step (2) is heated by a heater in the vaporizer 8. After heating, the liquid phase detoxified liquid is vaporized and evaporated in the vaporizer. The heating load of the heater is controlled by the pressure in the vaporizer to control the temperature of the solution in the vaporizer 8 to 130-165°C, the liquid level to 60-80%, and the pressure to 0.4-0.6 MPa. The pressure in the vaporizer 8 controls the heater load in the following manner: when the pressure in the vaporizer 8 is lower than the set pressure, the heater load is increased, thereby increasing the pressure and temperature in the vaporizer 8; when the pressure in the vaporizer 8 is higher than the set pressure, the heater load is reduced, thereby reducing the pressure in the vaporizer 8. A PLC is used to adjust the pressure and temperature in the vaporizer 8. The gas phase evaporated from the vaporizer 8 passes through a wire mesh demister and is then extracted from the top outlet to step (4).

[0049] (4) The gas phase of step (3) is flow-regulated by a regulating valve and then transported to the blast furnace gas pipeline through an injection pipe and an injector 9. The injector 9 is arranged in the pipeline after the gravity dust collector 2 and before the bag dust collector 3. Two or three groups of injectors are arranged, and each group of injectors has 10 to 20 small holes of φ2 to φ5 mm uniformly opened. A check valve and a shut-off valve are provided on the injection pipe to prevent the blast furnace gas from flowing back into the injection pipe and the vaporizer. The shut-off valve is interlocked with the pressure setting of the vaporizer. When the pressure in the vaporizer is lower than the pressure in the blast furnace gas pipeline, the shut-off valve is closed. The injection pipe needs steam or electric heating, and the heating temperature is greater than 130°C.

[0050] (5) Gas phase components and HCl, HF, HCN, HNO3, SO3 in blast furnace gas 2- 、SO4 2- The inorganic acid radical ions react to generate stable chlorides and salts attached to the blast furnace gas dust, which are captured by the bag filter 3 and then discharged through the lower dust collector of the bag filter 3. The blast furnace gas coming out of the bag filter 3 is hydrolyzed and catalytically converted through the protection reactor 4 and the hydrolysis reactor 5. The converted blast furnace gas goes to the TRT inlet.

[0051] The blast furnace gas is detoxified by the above-mentioned apparatus and process steps, which will be described in detail in the following examples.

[0052] Examples 1-5

[0053] Example 1-5 is a liquid phase detoxification liquid used in a liquid phase vaporization detoxification method for hydrolysis and desulfurization of blast furnace gas. The components and weight ratio of the liquid phase detoxification liquid are shown in Table 1.

[0054] Table 1 Components and weight ratios of the liquid phase detoxification solution of Examples 1-5

[0055]

[0056] The liquid detoxification liquid of Examples 1-5 was vaporized and then injected into blast furnace gas for detoxification. The total content of acidic poisons in the condensate before and after the blast furnace gas injection was analyzed. The specific analysis results are shown in Table 2.

[0057] Table 2 Detoxification effect of Examples 1-5

[0058]

[0059] It can be seen from Examples 1-5 that when the gas phase flow rate is injected at 25 kg / h, the acidic poison removal rate of liquid detoxification liquids of different concentrations in blast furnace gas with different flow rates can reach more than 90%. In order to further investigate the effect of different injection flow rates on the detoxification effect, the experiment of Example 6 was carried out on the basis of Example 4. Example 6

[0060] On the basis of Example 4, the gas phase injection amount was adjusted by controlling the gas phase outlet flow rate, thereby investigating the detoxification effect of different injection amounts on blast furnace gas, and the blast furnace gas flow rate was stabilized at 300,000 Nm 3 / h, temperature 130~150℃, pressure 0.2MPa, the gas phase out of the vaporizer is controlled by the regulating valve to flow rate of 15kg / h, 20kg / h, 25kg / h, 30kg / h, 36kg / h, 60kg / h, and the content of the vaporized gas phase in the coal gas is 50mg / m 3 , 66.7mg / m 3 , 83.3mg / m 3 , 100mg / m 3 , 120mg / m 3 , 200mg / m 3 The vaporized gas phase is then injected into the blast furnace gas pipeline through an injector for detoxification. The acid poison content of the condensate before and after the blast furnace gas injection is analyzed. The analysis results are shown in Table 3.

[0061] Table 3 Detoxification results of Example 6

[0062]

[0063] As can be seen from Example 6, after detoxification of blast furnace gas, the acidic poison content in the gas decreased significantly, and the pH of the blast furnace gas condensate increased from acidic to neutral or alkaline. With increasing injection rate, the acidic poison removal rate in the blast furnace gas gradually increased. Further increases in injection rate resulted in a slower increase in the acidic poison removal rate. The injected gas had no effect on the pressure drop of the blast furnace gas bag filter, and the bag filter discharged dust normally. Based on this, the effect of injected detoxification liquid on the service life of the hydrolysis catalyst was investigated. Specifically, the following procedures were performed: Under the conditions of Example 6, injection rate of 36 kg / h was continued and operation was maintained for a long period of time. The results are shown in Table 4.

[0064] Table 4 Spray 37.5kg / h detoxification treatment results

[0065] project Service life of hydrolysis catalyst Before spraying 2~3 months After injection More than 10 months

[0066] It can be seen from Table 4 that when the detoxification device is added and a certain injection volume is maintained, the service life of the blast furnace gas front-end fine desulfurization hydrolysis catalyst is greatly extended, thereby reducing the catalyst replacement cycle and directly reducing the blast furnace gas fine desulfurization operating cost, with significant results.

[0067] Although the embodiments of the present invention have been described and illustrated, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of protection claimed by the present invention shall be subject to the scope defined in the claims.

Claims

1. A liquid phase vaporization detoxification method suitable for blast furnace gas hydrolysis desulfurization process, characterized in that: Utilize the existing equipment of blast furnace, gravity dust collector, bag dust collector, protection reactor, hydrolysis reactor, and the pipes connecting the various components, and install a liquid phase vaporization detoxification device on the pipe after the gravity dust collector and before the bag dust collector. The liquid phase vaporization detoxification device mainly includes: solution buffer tank, solution delivery pump, vaporizer, ejector, as well as the connecting pipes between the various components and control system; The liquid phase vaporization detoxification device is used to vaporize the liquid phase detoxification liquid and then spray it into the blast furnace gas pipeline for detoxification reaction, thereby achieving gas phase removal of chlorides and other strongly acidic substances; The liquid phase vaporization detoxification method for blast furnace gas hydrolysis desulfurization process comprises the following steps: (1) Prepare the liquid phase detoxification solution. The mass percentages of the raw materials used are as follows: Organic amine 50~95 Antioxidant 0.5~5 Cosolvent 1~10 The remainder is demineralized water; The preparation method comprises the following steps: firstly adding an organic amine to deionized water, then sequentially adding an antioxidant and a cosolvent, and then stirring the mixture to form a homogeneous system, thereby finally obtaining a stable liquid-phase detoxification solution; wherein the organic amine is one or more of tert-butylamine, sec-butylamine, isobutylamine, n-hexylamine, ethanolamine, and N,N-dimethylethanolamine; the antioxidant is one or more of hydroquinone, resorcinol, and catechol; and the cosolvent is one or more of methanol, ethanol, and isopropanol. (2) The liquid phase detoxified liquid from step (1) is transported to a solution buffer tank via a ton barrel or tank truck, and a certain liquid level is maintained in the buffer tank; the liquid enters the solution delivery pump through the discharge valve at the bottom of the buffer tank, and enters the vaporizer after being pressurized; (3) After the solution of step (2) is heated in the vaporizer, the liquid phase detoxification liquid is completely vaporized in the vaporizer, and the pressure in the vaporizer is controlled to be 0.4-0.6 MPa, the temperature to be 130-165°C, and the liquid level to be 60-80%. The vaporized gas is extracted from the top of the vaporizer through a wire mesh demister and then transferred to step (4); (4) The gas phase of step (3) is flow-regulated by a regulating valve and then transported to the blast furnace gas pipeline through an injection pipe and an injector; the injectors are provided in two or three groups, each group of injectors has 10 to 20 small holes uniformly opened, and the injectors are provided in the pipeline after the gravity dust collector and before the bag dust collector; (5) Gas phase components and HCl, HF, HCN, HNO3, SO3 in blast furnace gas 2- 、SO4 2- Inorganic acid radical ions react to generate stable chlorides and salts that adhere to the blast furnace gas dust, are captured by the bag filter, and are then discharged through the lower dust collector of the bag filter.

2. The method according to claim 1, characterized in that The liquid phase detoxification solution is completely vaporized into gas phase within 130° C., and the solution pH is greater than 10.

3. The method according to claim 1, characterized in that In step (2), the solution delivery pump uses a variable frequency pump to control the solution delivery volume.

4. The method according to claim 1, wherein In step (3), a heater is provided in the vaporizer, and the temperature and pressure in the vaporizer are controlled by the heater. The liquid level in the vaporizer is interlocked with the solution delivery pump in step (2). When the liquid level in the vaporizer is lower than the low liquid level line, the solution delivery pump automatically starts. When the liquid level in the vaporizer is higher than the high liquid level, the solution delivery pump automatically stops. The vaporizer heater is interlocked with the liquid level of the vaporizer. When the liquid level gauge is lower than the lowest liquid level line, the vaporizer heater is turned off. The vaporizer and the pressure in the vaporizer are feedback-regulated. The material of the vaporizer is 316L.

5. The method according to claim 1, wherein In step (4), the size of the injector opening is φ2~φ5mm, and a check valve and a shut-off valve are provided on the injection pipe to prevent blast furnace gas from flowing back into the injection pipe and the vaporizer. The shut-off valve is interlocked with the pressure in the vaporizer. When the pressure in the vaporizer is lower than the pressure in the blast furnace gas pipe, the shut-off valve is closed. The injection pipe requires steam or electric heating, and the heating temperature is greater than 130°C.

6. The method according to claim 1, wherein In step (5), the blast furnace gas flow rate is 100,000~400,000 Nm 3 / h, pressure 0.15~0.2MPa, temperature 130~150℃, linear speed 15~30m / s, dust content less than 10mg / m 3 The content of gas phase after decomposition of liquid phase detoxification liquid in blast furnace gas is 50~200mg / m 3 The injection amount is adjusted in real time according to the concentration of hydrogen chloride acid poison at the gas outlet.

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