Desulfurizing agent as well as preparation method and application thereof

Abstract

The invention relates to the technical field of solid waste treatment, and discloses a desulfurizer preparation method, which comprises: (1) carrying out first heat treatment on a waste deacidification agent and / or a waste hydrolysis agent to obtain a material A; (2) dipping the material A in a metal salt solution to obtain a desulfurizer precursor; and (3) carrying out second heat treatment on the desulfurizer precursor to obtain the desulfurizer. The preparation method of the desulfurizer is simple, and the desulfurizer can be obtained only through the procedures of heat treatment, impregnation, secondary heat treatment and the like of the waste deacidification agent and / or the waste hydrolysis agent, so that the ecological environment problem caused by large-scale stockpiling or landfill of the waste deacidification agent and the waste hydrolysis agent is solved; and the prepared desulfurizer is used for a desulfurization process of a blast furnace gas fine desulfurization process, so that the operation cost of blast furnace gas fine desulfurization is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste treatment, and in particular to a desulfurizing agent and a preparation method and application thereof. Background Art

[0002] The dry process of fine desulfurization of blast furnace gas consists of the steps of deacidification-hydrolysis-desulfurization, in which the deacidification step is to remove acidic substances such as HCl and HCN in the blast furnace gas by using a deacidifier, the hydrolysis step is to convert carbonyl sulfide (COS) in the gas into hydrogen sulfide (H2S) by using a hydrolyzing agent (also called a hydrolysis catalyst), and the desulfurization step is to adsorb H2S in the gas by using a desulfurizing agent. In the dry process of fine desulfurization of blast furnace gas, the deacidification step and the hydrolysis step play a vital role. If the downstream sulfur content exceeds the standard, the deacidifier and the hydrolyzing agent need to be replaced. At present, the waste deacidifier and the waste hydrolyzing agent are mainly treated by stacking or landfilling, which not only wastes resources, but also may bring the risk of environmental pollution.

[0003] Therefore, how to provide a method for resource utilization of waste deacidification agents and waste hydrolysis agents is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0004] In view of this, the present invention uses waste deacidifying agent and / or waste hydrolyzing agent as raw materials to prepare desulfurizing agent, so as to solve the problem that solid wastes such as waste deacidifying agent and waste hydrolyzing agent replaced in the existing blast furnace gas fine desulfurization dry process are difficult to resource-process and dispose of.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a method for preparing a desulfurizing agent, comprising the following steps:

[0007] (1) subjecting the waste deacidification agent and / or waste hydrolysis agent to a first heat treatment to obtain material A;

[0008] (2) impregnating the material A in a metal salt solution to obtain a desulfurization agent precursor;

[0009] (3) The desulfurizing agent precursor is subjected to a second heat treatment to obtain a desulfurizing agent.

[0010] Preferably, the temperature of the first heat treatment in step (1) is 500-800° C. and the time is 5-20 h.

[0011] Preferably, the waste deacidifying agent is a deacidifying agent inactivated in a blast furnace gas desulfurization process, and the waste hydrolyzing agent is a hydrolyzing agent inactivated in a blast furnace gas desulfurization process.

[0012] Preferably, the impregnation is an equal volume impregnation.

[0013] Preferably, the active solution is a metal salt solution.

[0014] Preferably, the metal salt solution includes one or more of a metal nitrate solution, a metal sulfate solution, and a metal chloride solution.

[0015] Preferably, the impregnation step is: immersing the material A in a metal salt solution, performing ultrasonic treatment, and then allowing to stand.

[0016] Preferably, the frequency of the ultrasonic treatment is 18-40 kHz, and the time is 0.5-2 h.

[0017] Preferably, the standing time is 4-24 hours.

[0018] Preferably, the heat treatment temperature is 350-550° C. and the time is 5-10 h.

[0019] Preferably, before subjecting the spent deacidification agent and / or spent hydrolyzing agent to the first heat treatment, the method further comprises the following steps: removing impurities on the surface of the spent deacidification agent and / or spent hydrolyzing agent.

[0020] On the other hand, the present invention also provides a desulfurizing agent prepared by any of the above-mentioned preparation methods.

[0021] Furthermore, the present invention also provides a desulfurizer prepared by any of the preparation methods described above or the use of the desulfurizer in a blast furnace gas fine desulfurization process.

[0022] The present invention provides a desulfurizing agent and a preparation method and application thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0023] The preparation method of the desulfurizer of the present invention is simple, and only needs to subject the waste deacidifying agent and / or waste hydrolyzing agent to the first heat treatment, impregnation, second heat treatment and other processes, without the need for a large amount of equipment investment. The waste deacidifying agent and waste hydrolyzing agent have a high specific surface area and a relatively developed pore structure, and the desulfurizer is obtained by reloading the active components therein with the help of an active solution. This not only solves the ecological and environmental problems caused by large-scale storage or landfill of the waste deacidifying agent and waste hydrolyzing agent, but also uses the prepared desulfurizer for the desulfurization process of the blast furnace gas fine desulfurization process, effectively reducing the operating cost of the blast furnace gas fine desulfurization. DETAILED DESCRIPTION

[0024] The present invention will be described below by specific examples, and it will be appreciated by those skilled in the art that the following specific examples are only for illustrative purposes, and do not limit the scope of the present invention in any way. In addition, in the following examples, unless otherwise specified, the reagents and equipment used are all commercially available. If in the following examples, specific treatment conditions and treatment methods are not clearly described, then conditions and methods known in the art can be used to process.

[0025] In one aspect of the present invention, the present invention provides a method for preparing a desulfurizing agent, comprising the following steps:

[0026] (1) Removing impurities from the surface of spent deacidifying agent and / or spent hydrolyzing agent.

[0027] In the present invention, the waste deacidification agent and / or waste hydrolysis agent can be placed in an atmosphere such as air or nitrogen for purging to remove dust and other impurities on the surface thereof. There is no special limitation on parameters such as pressure during the purging process, and they can be adjusted conventionally.

[0028] (2) The spent deacidifying agent and / or spent hydrolyzing agent from which surface impurities have been removed is subjected to a first heat treatment to obtain material A.

[0029] In the present invention, the waste deacidifying agent and / or waste hydrolyzing agent from which surface impurities have been removed is placed in a muffle furnace for a first heat treatment, thereby removing volatile substances such as carbon black on the surface of the waste deacidifying agent and / or waste hydrolyzing agent and restoring the original specific surface area of ​​such materials.

[0030] In the present invention, the waste deacidification agent is a deacidification agent inactivated in the blast furnace gas fine desulfurization process, and the waste hydrolyzing agent is a hydrolyzing agent inactivated in the blast furnace gas fine desulfurization process, both of which have a high specific surface area and a developed pore structure. The waste deacidification agent and the waste hydrolyzing agent have similar components, both of which contain carbon black, dust, aluminum oxide, potassium chloride, potassium carbonate, sodium carbonate, sodium hydroxide, etc., but because the deacidification process is located at the front end of the hydrolysis process, the deacidification agent adsorbs more dust and carbon black. The dust attached to the surface of the waste catalyst and the waste hydrolyzing agent can be removed by step (1), and the volatile substances such as carbon black can be removed by the first heat treatment of step (2).

[0031] In the present invention, the temperature of the first heat treatment is 500-800°C, and the time is 5-20h. The first heat treatment temperature can be, for example, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, etc., and the time can be 5h, 10h, 15h, 20h, etc. If the temperature is too low, the carbon black volatile substances on the surface of the waste deacidification agent and / or the waste hydrolyzer cannot be effectively removed, and if the temperature is too high, the active components such as potassium carbonate, potassium sulfate, potassium chloride on the surface of the waste deacidification agent and / or the waste hydrolyzer will decompose and volatilize, reducing the sulfur capacity of the desulfurizer finally prepared.

[0032] (3) The material A is immersed in a metal salt solution to obtain a desulfurization agent precursor.

[0033] In the present invention, the metal salt solution is a metal salt solution, including one or more of a metal nitrate solution, a metal carbonate solution, a metal sulfate solution, and a metal chloride solution. Since the active component of the desulfurizer is a transition metal oxide such as iron oxide, copper oxide, and zinc oxide, and the nitrate solution of the transition metal oxide is easier to decompose, and nitrate is more soluble in water and has a higher solubility, which is conducive to the uniform loading of the active component, the metal salt solution is preferably a nitrate solution, such as iron nitrate, copper nitrate, zinc nitrate, etc. By adding the active solution, the loading rate of the active component on the surface and pores of the deacidifying agent and the hydrolyzing agent can be effectively improved.

[0034] In the present invention, the impregnation is an equal volume impregnation, and the amount of water required for the specific metal salt solution preparation process is determined according to the static water absorption rate of the waste deacidification agent and the waste catalyst. The present invention does not need to soak the waste deacidification agent and the waste hydrolyzer for desalination, and directly utilizes the characteristics of the waste deacidification agent and the waste hydrolyzer with a high specific surface and a more developed pore structure to prepare the desulfurizer precursor in an equal volume impregnation manner. In this process, the newly added metal salt can be loaded onto the surface and pores of the waste deacidification agent and the waste hydrolyzer, and the active components such as potassium carbonate, sodium carbonate, sodium hydroxide, etc. originally present in the waste deacidification agent and the waste hydrolyzer can also be reloaded onto the surface and pores of the waste deacidification agent and the waste hydrolyzer. The adsorption capacity of the waste deacidification agent and the waste hydrolyzer is improved, and this process does not produce any waste liquid, which is safe and environmentally friendly.

[0035] In the present invention, the impregnation step is: immersing the material A in a metal salt solution, performing ultrasonic treatment, and then standing. Wherein, the frequency of the ultrasonic treatment is 18-40kHz, the time is 0.5-2h, and the standing time is 4-24h. Wherein, the ultrasonic frequency can be, for example, 18kHz, 25kHz, 30kHz, 35kHz, 40kHz, etc., the ultrasonic time can be, for example, 0.5h, 1h, 1.5h, 2h, etc., and the standing time can be 4h, 10h, 15h, 20h, 24h, etc. The ultrasonic treatment process can make the active components such as potassium carbonate, sodium carbonate, and sodium hydroxide disperse more evenly on the surface and pores of the waste deacidification agent and the waste hydrolyzer, and at the same time, the active components on the surface of the waste deacidification agent and the waste hydrolyzer can be reloaded, thereby improving the adsorption capacity of the desulfurizer, and the loading process can be stabilized during the standing process, so that the active molecules can be fully attached to the surface and pores of the waste deacidification agent and the waste hydrolyzer.

[0036] (4) The desulfurizing agent precursor is subjected to a second heat treatment to obtain a desulfurizing agent.

[0037] In the present invention, the desulfurizer precursor can be placed in a muffle furnace for a second heat treatment to remove the moisture adsorbed by the waste deacidifying agent and the waste hydrolyzing agent in step S300. In addition, since the active components in the active solution used in the impregnation loading process are metal oxides such as copper oxide, zinc oxide, and iron oxide, the metal salts such as copper nitrate and zinc nitrate can be decomposed into metal oxides such as iron oxide and copper oxide through the second heat treatment, and then the metal oxides such as iron oxide and copper oxide are used as active components to react with hydrogen sulfide to generate metal sulfides.

[0038] In the present invention, the temperature of the second heat treatment is 350-550°C, and the time is 5-10h. The second heat treatment temperature can be, for example, 350°C, 400°C, 450°C, 500°C, 550°C, etc. If the second heat treatment temperature is too high, the potassium carbonate, potassium sulfate and other substances originally present in the waste deacidification agent and the waste hydrolyzing agent will decompose, and the energy consumption is high; if the second heat treatment temperature is too low, the newly added active components such as copper nitrate and iron nitrate will not decompose. Since the desulfurization active components are oxides rather than metal salts, the desulfurization effect of the desulfurizer finally prepared will be affected.

[0039] In another aspect of the present invention, the present invention also provides a desulfurizer prepared by the above-mentioned preparation method, which has high sulfur capacity, good adsorption capacity and high strength. Since the desulfurizer is prepared using the method described above, the desulfurizer has all the characteristics and advantages of the method described above, which will not be repeated here.

[0040] In another aspect of the present invention, the present invention also provides a desulfurizer prepared by the above preparation method or the use of the desulfurizer in a blast furnace gas fine desulfurization process.

[0041] The waste deacidifying agent involved in the following embodiments or comparative examples is a deacidifying agent inactivated in the blast furnace gas fine desulfurization process, and its composition and the mass content of each component are as follows: 2.5% potassium chloride, 5.8% potassium carbonate, 1.7% potassium sulfate, and 90% aluminum oxide.

[0042] The waste hydrolyzing agent is a deactivated hydrolyzing agent in the blast furnace gas desulfurization process, and its composition is as follows: 0.3% potassium chloride, 8.2% potassium carbonate, 1.5% potassium sulfate, and 90% aluminum oxide.

[0043] Example 1

[0044] (1) After purging the waste hydrolyzing agent under air atmosphere for 1 hour, the waste hydrolyzing agent was placed in a muffle furnace and heat treated at 550° C. for 5 hours to obtain material A;

[0045] (2) dissolving copper nitrate in distilled water and stirring until completely dissolved to obtain a copper nitrate solution; wherein the volume ratio of the amount of distilled water added to the sum of the water absorption of the waste deacidification agent and the waste hydrolyzing agent is 1:1, and the mass of copper oxide in the copper nitrate accounts for 20% of that of the desulfurization agent;

[0046] (3) immersing material A in a copper nitrate solution for 1 hour and then allowing to stand for 4 hours to obtain a desulfurization agent precursor;

[0047] (4) The desulfurizer precursor is placed in a muffle furnace and heat treated at 350° C. for 5 h to obtain a desulfurizer.

[0048] The sulfur capacity of the desulfurizer prepared in this example is 112 mg / g, and the strength is 132 N / cm. The sulfur capacity test method is in accordance with "HG / T 5759-2020 Normal Temperature Iron Oxide Desulfurizer"; the strength test method is in accordance with the part of the average value of the crushing resistance of spherical desulfurizer particles in "HG / T 5759-2020 Normal Temperature Iron Oxide Desulfurizer".

[0049] Example 2

[0050] (1) After purging the waste hydrolyzing agent under air atmosphere for 1 hour, the waste hydrolyzing agent was placed in a muffle furnace and heat treated at 550° C. for 5 hours to obtain material A;

[0051] (2) dissolving zinc nitrate in distilled water and stirring until completely dissolved to obtain a zinc nitrate solution; wherein the volume ratio of the amount of distilled water added to the sum of the water absorption of the waste deacidification agent and the waste hydrolyzing agent is 1:1, and the mass of zinc oxide in the zinc nitrate accounts for 20% of that of the desulfurization agent;

[0052] (3) immersing material A in a copper nitrate solution for 1 hour and then allowing to stand for 4 hours to obtain a desulfurization agent precursor;

[0053] (4) The desulfurizer precursor is placed in a muffle furnace and heat treated at 550° C. for 5 h to obtain a desulfurizer.

[0054] The desulfurizer prepared in this example has a sulfur capacity of 110 mg / g and a strength of 135 N / cm.

[0055] Example 3

[0056] (1) After the waste hydrolyzing agent is purged under air atmosphere for 1 hour, it is placed in a muffle furnace and heat treated at 800° C. for 5 hours to obtain material A;

[0057] (2) dissolving ferric nitrate in distilled water and stirring until completely dissolved to obtain a ferric nitrate solution; wherein the volume ratio of the amount of distilled water added to the sum of the water absorption of the waste deacidification agent and the waste hydrolyzing agent is 1:1, and the mass of iron oxide in the ferric nitrate accounts for 20% of the mass of the desulfurization agent;

[0058] (3) immersing material A in a copper nitrate solution for 1 hour and then allowing to stand for 4 hours to obtain a desulfurization agent precursor;

[0059] (4) The desulfurizer precursor is placed in a muffle furnace and heat treated at 350° C. for 5 h to obtain a desulfurizer.

[0060] The desulfurizer prepared in this example has a sulfur capacity of 120 mg / g and a strength of 132 N / cm.

[0061] Example 4

[0062] (1) After purging the waste hydrolyzing agent under air atmosphere for 1 hour, the waste hydrolyzing agent was placed in a muffle furnace and heat treated at 550° C. for 5 hours to obtain material A;

[0063] (2) dissolving a mixture of copper nitrate and zinc nitrate in distilled water and stirring until completely dissolved to obtain a ferric nitrate solution; wherein the volume ratio of the amount of distilled water added to the sum of the water absorption of the waste deacidification agent and the waste hydrolyzing agent is 1:1, the mass of copper oxide and zinc oxide in the copper nitrate and zinc nitrate accounts for 20% of the desulfurization agent, and the molar ratio of copper oxide to zinc oxide is 1:1;

[0064] (3) immersing material A in a copper nitrate solution for 1 hour and then allowing to stand for 4 hours to obtain a desulfurization agent precursor;

[0065] (4) The desulfurizer precursor is placed in a muffle furnace and heat treated at 450° C. for 5 h to obtain a desulfurizer.

[0066] The desulfurizer prepared in this example has a sulfur capacity of 123 mg / g and a strength of 136 N / cm.

[0067] Example 5

[0068] This embodiment is basically the same as embodiment 4, with the only difference being that in step (1), heat treatment is performed at 500° C. for 5 h.

[0069] The desulfurizer prepared in this example has a sulfur capacity of 125 mg / g and a strength of 136 N / cm.

[0070] Example 6

[0071] Example 6 is substantially the same as Example 4, the only difference being that the waste hydrolyzing agent is replaced by a mixture of the waste hydrolyzing agent and the waste deacidifying agent in a mass ratio of 1:1.

[0072] The desulfurizer prepared in this example has a sulfur capacity of 105 mg / g and a strength of 135 N / cm.

[0073] Example 7

[0074] Example 7 is substantially the same as Example 4, the only difference being that the waste hydrolyzing agent is replaced by the waste deacidifying agent.

[0075] The desulfurizer prepared in this example has a sulfur capacity of 95 mg / g and a strength of 135 N / cm.

[0076] Comparative Example 1

[0077] This comparative example is basically the same as Example 4, with the only difference being that in step (1), heat treatment is performed at 850° C. for 5 h.

[0078] The desulfurizer prepared in this comparative example has a sulfur capacity of 90 mg / g and a strength of 128 N / cm.

[0079] By comparing Example 4 with Comparative Example 1, it can be seen that if the first heat treatment temperature is too high, active components such as potassium carbonate, potassium sulfate, potassium chloride on the surface of the waste deacidifying agent and / or waste hydrolyzing agent may decompose and volatilize, reducing the sulfur capacity of the desulfurizing agent finally prepared.

[0080] Comparative Example 2

[0081] This comparative example is basically the same as Example 4, the only difference being that in step (2), the volume ratio of the amount of distilled water added to the sum of the water absorption of the waste deacidification agent and the waste hydrolyzing agent is 1.2:1.

[0082] The desulfurizer prepared in this comparative example has a sulfur capacity of 120 mg / g and a strength of 130 N / cm.

[0083] By comparing Example 4 with Comparative Example 2, it can be seen that if the amount of distilled water added during the impregnation process is large, the sulfur capacity and strength of the desulfurizer finally prepared are equivalent to those of the same volume impregnation, but it will cause a certain amount of solution waste, so equal volume impregnation is preferred.

[0084] Comparative Example 3

[0085] This comparative example is basically the same as Example 4, with the only difference being that in step (4), heat treatment is performed at 900° C. for 5 h.

[0086] The desulfurizer prepared in this comparative example has a sulfur capacity of 90 mg / g and a strength of 134 N / cm.

[0087] By comparing Example 4 with Comparative Example 3, it can be seen that if the temperature of the second heat treatment process is too high, potassium carbonate, potassium sulfate and other substances originally present in the waste deacidification agent and waste hydrolysis agent will decompose, resulting in a lower sulfur capacity of the desulfurization agent finally prepared.

[0088] In summary, the desulfurizer prepared by using waste deacidifying agent and waste hydrolyzing agent in the present invention has good sulfur capacity and strength, and can achieve good desulfurization effect by using it in the desulfurization process of blast furnace gas fine desulfurization process.

[0089] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a desulfurizing agent, characterized in that: The following steps are involved: (1) subjecting the waste deacidification agent and / or waste hydrolysis agent to a first heat treatment to obtain material A; (2) impregnating the material A in a metal salt solution to obtain a desulfurization agent precursor; (3) The desulfurizing agent precursor is subjected to a second heat treatment to obtain a desulfurizing agent.

2. The method for preparing a desulfurizing agent according to claim 1, characterized in that: In step (1), the temperature of the first heat treatment is 500-800°C and the time is 5h-20h.

3. The method for preparing a desulfurizing agent according to claim 1, characterized in that: The waste deacidifying agent is a deacidifying agent that is inactivated in the blast furnace gas fine desulfurization process; The waste hydrolyzing agent is a hydrolyzing agent deactivated in a blast furnace gas fine desulfurization process.

4. The method for preparing a desulfurizing agent according to claim 1, characterized in that: The impregnation is equal volume impregnation.

5. The method for preparing a desulfurizing agent according to claim 1, characterized in that: The metal salt solution includes one or more of a metal nitrate solution, a metal sulfate solution, and a metal chloride solution.

6. The method for preparing a desulfurizing agent according to claim 1, characterized in that: The impregnation step is: immersing the material A in a metal salt solution, performing ultrasonic treatment, and then standing; Wherein, the frequency of the ultrasonic treatment is 18-40kHz, and the time is 0.5-2h; The standing time is 4-24h.

7. The method for preparing a desulfurizing agent according to claim 1, characterized in that: The temperature of the second heat treatment in step (3) is 350-550°C and the time is 5-10h.

8. The method for preparing a desulfurizing agent according to any one of claims 1 to 7, characterized in that: Before subjecting the spent deacidifying agent and / or spent hydrolyzing agent to the first heat treatment, the method further comprises the following steps: removing impurities on the surface of the spent deacidifying agent and / or spent hydrolyzing agent.

9. A desulfurizing agent prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the desulfurizer prepared by the preparation method according to any one of claims 1 to 8 or the desulfurizer according to claim 9 in a blast furnace gas fine desulfurization process.