A composite oxide desulfurizer based on iron-containing and zinc-containing dust sludge and a preparation method thereof

Abstract

The present application relates to a kind of composite oxides desulfurizer based on iron-containing zinc-containing dust mud and preparation method, comprising the following steps: blast furnace gas ash and converter dust mixing and washing, obtain dust slag;Dust slag is digested by acid leaching, and the digested solution containing iron, zinc and calcium is obtained by filtration;Surfactant and lye are added to the digested solution, and stirring reaction is carried out until precipitation is complete, to obtain suspension liquid;Suspension liquid is filtered, and the filter cake obtained is dried, ground and calcined, to obtain composite iron zinc calcium oxide;Composite iron zinc calcium oxide, pore-forming agent, adhesive, active additive and water are mixed uniformly, then extruded into shape, dried and calcined, to obtain composite oxide desulfurizer.The present application obtains composite iron zinc calcium oxide by acid leaching purification of blast furnace gas ash and converter dust, then kneads and calcines after mixing with additives, to obtain efficient composite iron zinc desulfurizer, which is used for removal of sulfide in blast furnace gas, and has high adsorption capacity for sulfur.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, specifically to a composite oxide desulfurizing agent based on iron- and zinc-containing dust and sludge and its preparation method. Background Technology

[0002] Iron-zinc dust and sludge, mainly comprising sintering dust, blast furnace gas ash / sludge, electric furnace dust, converter dust / sludge, and iron oxide scale, currently amounts to approximately 100 million tons annually. The improper utilization of these large quantities of solid waste can lead to significant consequences, including land occupation, environmental pollution, resource waste, and economic losses. Historically, most of this iron-zinc dust and sludge has been forcibly recycled by the steel industry and directly returned to sintering for reuse. However, this dust and sludge contains large amounts of harmful components such as Zn, Ca, K, Na, S, and Cl, exhibiting strong corrosiveness and adhesiveness. The continuous accumulation of these harmful elements during the production cycle adversely affects the iron-containing furnace charge and refractory materials within the furnace, consequently impacting the stable operation and lifespan of the blast furnace, resulting in poor economic efficiency and high safety hazards. Considering that the desulfurizing agents used in the fine desulfurization of blast furnace gas are iron oxide and zinc oxide, and that doping zinc into iron oxide can improve the absorption efficiency of H2S without affecting the regeneration of iron oxide, and that calcium oxide can also absorb H2S, theoretically, the iron, zinc and calcium elements in these dust and sludge can be used to prepare catalysts for the fine desulfurization of blast furnace gas. This would reduce the harm caused by the direct recycling of dust and sludge in the converter and enable resource recycling, thereby reducing the cost of treating pollutants in steel smelting tail gas. However, there are still some difficulties in actual operation.

[0003] Currently, some patent reports also utilize solid waste from industrial production to prepare desulfurizing agents. For example, patent CN113634115A discloses an iron oxide desulfurizing agent and its preparation method. After crushing slag iron ore, water is directly added to form a slurry, which is then mixed with active additives, a carrier, and a binder to produce the iron oxide desulfurizing agent. Patent CN101745309B discloses a method for using fly ash or blast furnace slag for flue gas desulfurization and comprehensive utilization. Blast furnace slag, ammonium fluoride, and water are mixed, and then pyrolusite and ferrous sulfate are added to prepare a desulfurization slurry. The slurry absorbs SO2 from the flue gas. Patent CN102424764B discloses a method for preparing a desulfurizing agent using steelmaking red mud. The steelmaking red mud is ground into a fine powder, kneaded with polystyrene microsphere emulsion, bentonite, and calcium stearate, and then calcined to obtain an iron oxide desulfurizing agent. These patents all directly utilize slag powder and auxiliary additives to obtain solid or slurry desulfurizing agents through simple mechanical mixing to absorb sulfides. The active phase is unevenly distributed and not fully utilized, with many impurities and limited adsorption capacity for sulfur. Moreover, the active components are singular and cannot be applied to complex working conditions. At the same time, there is currently little research on the preparation of desulfurizing agents using blast furnace gas ash and steelmaking converter dust. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a composite oxide desulfurizer based on iron- and zinc-containing dust and sludge and its preparation method, thereby solving the technical problems of limited adsorption capacity of desulfurizers and low utilization rate of blast furnace gas ash and converter dust in the prior art.

[0005] To achieve the above-mentioned technical objectives, the technical solution provided by this invention is as follows:

[0006] In a first aspect, the present invention provides a method for preparing a composite oxide desulfurizing agent based on iron- and zinc-containing dust and sludge, comprising the following steps:

[0007] (1) Mix and wash the blast furnace gas ash and converter dust to obtain dust residue;

[0008] (2) The dust residue was acid-leached and digested, and filtered to obtain a digestion solution containing iron, zinc and calcium;

[0009] (3) Add surfactant and alkali solution to digestion solution, stir until precipitation is complete, and obtain suspension;

[0010] (4) The suspension was filtered, and the resulting filter cake was dried, ground and calcined to obtain composite iron-zinc-calcium oxide;

[0011] (5) After the composite iron-zinc calcium oxide, pore-forming agent, binder, active additive and water are mixed evenly, they are extruded and shaped, dried and then calcined to obtain the composite oxide desulfurizer.

[0012] Preferably, in step (1), blast furnace gas ash and converter dust are mixed at a mass ratio of (7-10):1. Blast furnace gas ash and converter dust are generated in the ironmaking and steelmaking processes of steel plants.

[0013] Preferably, in step (1), after mixing blast furnace gas ash and converter dust, mixed dust is obtained. Water is added to the mixed dust at a ratio of 2kg:(2~4)L for washing, and the washing time is 2~4h. Then, the dust is filtered to obtain slag.

[0014] Preferably, in step (2), acid leaching digestion is carried out by mixing the dust and acid solution at a ratio of 1 kg: (1-3) L and heating and stirring; the concentration of the acid solution is 0.5-5 mol / L.

[0015] In a further preferred embodiment, the heating temperature during acid leaching and digestion is 60–100°C; the stirring time is 2–4 hours; and the acid solution includes one or more of sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, hydrogen peroxide, perchloric acid, and aqua regia.

[0016] Preferably, in step (3), the surfactant includes one or more of polyethylene glycol, sodium dodecyl sulfonate, polyvinyl alcohol, hexadecyltrimethylammonium bromide, ethylenediamine, sodium dodecylbenzene sulfonate, etc.; the amount of surfactant used is 5 to 20% of the mass of the dust and sludge after cleaning.

[0017] Preferably, in step (3), after adding the surfactant to the digestion solution, the mixture is stirred for 2 to 6 hours to dissolve it completely; after adding the alkali solution, the mixture is stirred at 60 to 100°C and the pH of the digestion solution is adjusted to 7 to 10 until iron, zinc and calcium are completely precipitated.

[0018] More preferably, the concentration of the alkali solution is 0.5–2 mol / L; the alkali in the alkali solution includes one or more of the following: sodium hydroxide, ammonia, urea, sodium carbonate, ammonium carbonate, and ammonium bicarbonate.

[0019] Preferably, in step (4), the filter cake is dried in an oven at 80-120°C for 6-24 hours; the calcination is carried out in a muffle furnace under an air atmosphere, first at a low temperature of 100-300°C for 4-10 hours, and then at 300-700°C for 6-12 hours.

[0020] Preferably, in step (5), the adhesive includes one or more of polyethylene oxide, guar gum powder, silica sol, glycerin, starch, boehmite, calcium oxide, and clay; the pore-forming agent includes one or more of starch, sawdust, polyvinyl alcohol, methyl methacrylate, ammonium bicarbonate, and toner; and the active additives include one or more of zinc chloride, basic zinc carbonate, γ-Al2O3, sodium carbonate, potassium carbonate, and ammonium bicarbonate.

[0021] Preferably, in step (5), the materials comprise, by mass percentage, 75-90% composite oxide dry powder, 2-15% pore-forming agent, 3-15% adhesive, 3-19% active additive, and 1-2% water.

[0022] Preferably, in step (5), the composite iron-zinc calcium oxide, pore-forming agent, binder, active additive and water are mixed first and then sent to a high-power mixer for mixing, and the mixing time is 5 to 10 minutes.

[0023] Preferably, in step (5), drying involves placing the extruded sample in a cool place at room temperature for 12–24 hours, and then placing it in an oven at 60–120°C for 6–24 hours.

[0024] Preferably, in step (5), the roasting is carried out in a muffle furnace under an air atmosphere, first at a low temperature of 100-300℃ for 4-10 hours, and then at 300-700℃ for 6-12 hours.

[0025] Secondly, the present invention provides a composite oxide desulfurizer prepared by the above preparation method.

[0026] Compared with the prior art, the beneficial effects of the present invention include:

[0027] 1. This invention purifies blast furnace gas ash and converter dust by acid leaching to obtain iron-zinc composite oxides, which are then mixed with binders, pore-forming agents, and active additives, followed by kneading and calcination to obtain a highly efficient composite iron-zinc-calcium oxide desulfurizer. This desulfurizer is used for the removal of sulfides from blast furnace gas, exhibiting a high sulfur adsorption capacity and a sulfur penetration capacity of up to 56%. This invention utilizes dust and sludge generated during steel smelting to prepare the desulfurizer, enabling resource recycling of solid waste, reducing the environmental harm caused by dust and sludge, and lowering actual production costs.

[0028] 2. By utilizing the iron and zinc contained in the dust and sludge to synthesize a composite iron-zinc-calcium oxide desulfurizer, the adsorption and reaction sites for H2S are increased, which is beneficial to the absorption of H2S.

[0029] 3. The surfactant added to the digestion solution can combine with metal ions to form chelates, inducing the iron species to transform into highly active iron oxide crystal phase, thereby improving the absorption effect of the desulfurizer on H2S.

[0030] 4. The present invention employs a two-stage calcination process, which facilitates the slow release of surfactants and pore-forming agents, while also enhancing the interaction between iron-zinc oxides and additives, thereby improving desulfurization efficiency. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 merely illustrative and not intended to limit the invention.

[0033] To efficiently utilize the iron and zinc elements in blast furnace gas ash and converter dust, this invention proposes a composite oxide desulfurizer based on iron- and zinc-containing dust and sludge, and its preparation method. The aim is to achieve green and low-carbon treatment of iron- and zinc-containing dust and sludge, especially solid wastes such as blast furnace gas ash and converter dust, through a simple and easy preparation method, and to obtain a low-cost blast furnace gas desulfurizer. This will enable the efficient utilization of iron- and zinc-containing dust and sludge in the steel industry and contribute to the reduction of pollution emissions from steel smelting tail gas.

[0034] See Figure 1This invention provides a composite oxide desulfurizer based on iron- and zinc-containing dust and sludge, and its preparation method. The preparation method is simple and feasible, utilizing iron- and zinc-containing dust and sludge from iron and steel smelting to prepare a highly efficient blast furnace gas desulfurizer for the efficient utilization of solid waste and reduction of industrial exhaust gas emissions in the steel industry. Specifically, it includes the following steps:

[0035] (1) Mix blast furnace gas ash and converter dust ash and wash with water to obtain dust residue;

[0036] (2) The dust residue was acid-leached and digested, and filtered to obtain a digestion solution containing iron, zinc and calcium; after digestion, the metals exist in the solution in ionic form;

[0037] (3) Add surfactant and alkali to digestion solution, stir to neutralize until precipitation is complete, and obtain suspension;

[0038] (4) The suspension was filtered and washed with water. The resulting filter cake was dried, ground and calcined to obtain composite iron-zinc-calcium oxide.

[0039] (5) After the composite iron-zinc calcium oxide, pore-forming agent, binder, active additive and water are mixed evenly, they are extruded and shaped, dried and then calcined to obtain the composite oxide desulfurizer.

[0040] In this invention, the addition of a surfactant first promotes the formation of metal chelates between metal ions and surfactant groups. Then, an alkaline solution is added for neutralization. After calcination, the formation of a highly active iron oxide crystal phase is effectively promoted, thereby improving the absorption effect of the desulfurizer on H2S.

[0041] The present invention will be further described in detail below through specific embodiments. The blast furnace gas ash and converter dust are dust and slag generated during the ironmaking and steelmaking processes in steel plants.

[0042] Example 1

[0043] (1) Mix blast furnace gas ash and converter dust at a mass ratio of 9:1. Take 2 kg of the mixture and put it into 3000 mL of clean water and stir and wash for 2 hours. Filter and wash to obtain clean dust.

[0044] (2) Place 1 kg of cleaned dust into a 3000 mL tank of 2 mol / L sulfuric acid solution and stir mechanically at 90 °C for 2 h to completely dissolve it. Then filter it in a filter bucket to obtain a digestion solution containing iron, zinc and calcium.

[0045] (3) Weigh 100g of polyethylene glycol and dissolve it in the digestion solution above, stirring for 3 hours until it is completely dissolved. Slowly add 0.5mol / L sodium hydroxide solution to the digestion solution above, and stir at 90℃ to allow it to react fully. Adjust the pH of the solution to 8 until the iron, zinc and calcium in the solution are completely precipitated, resulting in a suspension containing a mixed precipitate of iron hydroxide, zinc hydroxide and calcium hydroxide.

[0046] (4) After the above suspension is filtered and washed, the filter cake is placed in a 100°C oven for 12 hours to dry the moisture. Then the filter cake is ground into powder and then calcined in a muffle furnace at 250°C for 4 hours in an air atmosphere and calcined at 450°C for 6 hours to obtain composite iron-zinc-calcium oxide.

[0047] (5) The composite iron-zinc-calcium oxide, pore-forming agent, binder, active additive, and water obtained above are mixed in a ratio of 80:5:5:9:1 and fed into a high-power mixer for 10 minutes. The mixed material is then extruded using a screw extruder. The extruded sample is first placed at room temperature in a cool place for 24 hours, then placed in a 100°C oven for 24 hours, and subsequently calcined in a muffle furnace at a low temperature of 250°C for 4 hours in an air atmosphere, and then calcined at 450°C for 6 hours to obtain the composite oxide desulfurizer.

[0048] Comparative Example 1

[0049] The difference from Example 1 is that the digestion step (2) and the neutralization and precipitation step (3) are removed, while the other steps and conditions are the same as in Example 1; that is, after the dust and sludge are washed, they are crushed and then mixed directly with pore-forming agent, binder, active additive and water in a ratio of 80:5:5:9:1 without digestion and neutralization, and then kneaded to make desulfurizing agent.

[0050] Comparative Example 2

[0051] The difference from Example 1 is that the step of adding the surfactant in step (3) is omitted; all other steps and conditions are the same as in Example 1. The difference lies in:

[0052] (3) Measure 0.5 mol / L sodium hydroxide solution and slowly add it to the above digestion solution. Stir at 90°C to allow it to react fully. Adjust the pH of the solution to 8 until the iron, zinc and calcium in the solution are completely precipitated, and a mixed precipitate of iron hydroxide, zinc hydroxide and calcium hydroxide is obtained.

[0053] Comparative Example 3

[0054] The difference from Example 1 is that the blast furnace gas ash in step (1) is removed, and only converter dust is used as the raw material; the other steps and conditions are the same as in Example 1. The difference is:

[0055] (1) 2 kg of converter dust collected from the steelmaking process was placed in 3000 mL of clean water and stirred and washed for 2 hours. The clean dust was obtained by filtration and washing.

[0056] Comparative Example 4

[0057] The difference from Example 1 is that the converter dust in step (1) is removed, and only blast furnace gas ash is used as the raw material; the other steps and conditions are the same as in Example 1. The difference is:

[0058] (1) 2 kg of blast furnace gas ash collected from the ironmaking process was placed in 3000 mL of clean water and stirred and washed for 2 hours. The ash was then filtered and washed to obtain clean dust.

[0059] Comparative Example 5

[0060] The difference from Example 1 is that the low-temperature roasting process in steps (4) and (6) is removed, and the roasting conditions in steps (4) and (5) are changed to roasting only in a muffle furnace at 450°C for 6 hours in an air atmosphere; the other steps and conditions are the same as in Example 1. The difference is:

[0061] (4) After the above suspension is filtered and washed, the filter cake is placed in a 100°C oven for 12 hours to dry the moisture. Then the filter cake is ground into powder and then calcined in a muffle furnace at 450°C in air atmosphere for 6 hours.

[0062] (5) The composite iron-zinc oxide obtained above, along with pore-forming agent, binder, active additive, and water, are mixed in a ratio of 80:5:5:9:1 and fed into a high-power mixer for 10 minutes. The mixed material is then extruded using a screw extruder. The extruded sample is first placed at room temperature in a cool place for 24 hours, then placed in a 100°C oven for 24 hours, and subsequently calcined in a muffle furnace at 450°C in air atmosphere for 6 hours.

[0063] Performance testing

[0064] The desulfurizing agents prepared in Example 1 and Comparative Examples 1-5 were evaluated for their fine desulfurization activity. The specific evaluation steps included:

[0065] Weigh 1.0g of desulfurizing agent and fill it into the center of the quartz tube (0.8cm inner diameter) adsorption column of the fixed-bed tubular furnace. Then, introduce 2010mg / Nm³ of desulfurizing agent. 3 The activity test was conducted using a mixed atmosphere of H2S, 0.3% O2, and N2 as the equilibrium gases. The total flow rate of the experimental gases was 500 mL / min, and the reaction space velocity was 1000 h⁻¹. -1Open the gas valve switch and adjust each gas path to the specified concentration according to the operating conditions, maintaining stable airflow. Set the temperature to 40℃. Control the relative humidity of the mixed atmosphere by adjusting the N2 flow rate, ensuring the relative humidity of the reaction atmosphere is 60%. After the conditions stabilize, pass the mixed gas containing a certain concentration of hydrogen sulfide through the adsorption column. Use an SP-6802 gas chromatograph to monitor the outlet concentration online, measuring the outlet tail gas content at 30-minute intervals. The outlet tail gas is absorbed with alkaline solution. When the hydrogen sulfide outlet concentration reaches 10% of the inlet concentration, it is considered that H2S has penetrated. Continue monitoring until the outlet concentration reaches 90% of the inlet concentration, which is considered that H2S has been adsorbed saturated, and stop the measurement. Use a wet gas flow meter to record the flow rates at the beginning and penetration points to calculate the breakthrough sulfur capacity.

[0066] The desulfurization activity test results of the desulfurizing agents prepared in Example 1 and Comparative Examples 1-5 as catalysts / adsorbents are shown in Table 1 below.

[0067] Table 1. Desulfurization activity test results of the desulfurizing agents prepared in Example 1 and Comparative Examples 1-5.

[0068] Example 1 56 Comparative Example 1 43 Comparative Example 2 50 Comparative Example 3 48 Comparative Example 4 51 Comparative Example 5 52

[0069] As shown in Table 1, the present invention optimizes the formulation and preparation method of the desulfurizing agent, thereby improving the desulfurization efficiency of the desulfurizing agent.

[0070] (1) Firstly, in terms of the raw materials used in the desulfurizing agent, the present invention uses blast furnace gas ash and converter dust ash to replace the traditional ferrous sulfate source, thereby realizing the resource utilization of iron and steel metallurgical solid waste. As can be seen from Example 1 and Comparative Examples 3 and 4, the present invention can effectively improve the desulfurization effect by compounding blast furnace gas ash and converter dust ash in a certain proportion.

[0071] (2) On the other hand, the present invention adds a surfactant during the iron oxide synthesis process. The chelate formed by the surfactant and iron ions can regulate the generation of active iron oxide species and improve the desulfurization efficiency. The desulfurization machine obtained after removing the surfactant in Comparative Example 2 showed a significant decrease in the sulfur penetration capacity, which also proves this point.

[0072] (3) The digestion and neutralization precipitation steps were removed in Comparative Example 1, and the dust and slag were directly kneaded, which contained a lot of impurities and did not fully activate the H2S adsorption and reaction sites.

[0073] (4) Example 1 adopted a segmented calcination process compared with Comparative Example 5, which helps the slow release of surfactants and pore-forming agents, while enhancing the interaction between iron and zinc oxides and additives, and improving desulfurization efficiency.

[0074] (5) This invention utilizes iron- and zinc-containing dust and sludge generated during steel smelting to prepare a desulfurizing agent for fine desulfurization of blast furnace gas, thereby realizing the recycling of resources in the steel industry and helping the steel industry reduce pollution and carbon emissions.

[0075] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a composite oxide desulfurizing agent based on iron- and zinc-containing dust and sludge, characterized in that, Includes the following steps: (1) Mix and wash the blast furnace gas ash and converter dust to obtain dust residue; (2) The dust and residue were acid-soaked and digested, and the digestion solution was obtained by filtration; (3) First, add surfactant to digestion solution to dissolve it completely, then add alkali solution and stir to neutralize until precipitation is complete, and obtain suspension; (4) The suspension is filtered, and the resulting filter cake is dried, ground, and calcined. The calcination is carried out in a muffle furnace under an air atmosphere, first at a low temperature of 100-300°C. o Calcination at C for 4–10 hours, followed by heating at 300–700 °C o Calcination at C for 6–12 h yields composite iron-zinc-calcium oxide; (5) The composite iron-zinc calcium oxide, pore-forming agent, binder, active additive and water are mixed evenly and then extruded into shape, dried and then calcined. The calcination is carried out in a muffle furnace under an air atmosphere, first at a low temperature of 100-300°C. o Calcination at C for 4–10 hours, followed by heating at 300–700 °C o The composite oxide desulfurizer was obtained by calcining at C for 6–12 h.

2. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (1), blast furnace gas ash and converter dust are mixed at a mass ratio of (7-10):1 to obtain mixed dust. Water is added to the mixed dust at a ratio of 2kg:(2-4)L for washing, and the washing time is 2-4 hours. The dust is then filtered to obtain slag.

3. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (2), acid leaching and digestion is carried out by mixing the dust and acid solution at a ratio of 1 kg: (1-3) L and heating and stirring; the concentration of the acid solution is 0.5-5 mol / L. In the acid leaching digestion, the heating temperature is 60-100°C. o C; Stirring time is 2–4 hours; Acids include one or more of sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid, hydrogen peroxide, perchloric acid, and aqua regia.

4. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (3), the surfactant includes one or more of polyethylene glycol, sodium dodecyl sulfonate, polyvinyl alcohol, hexadecyltrimethylammonium bromide, ethylenediamine, and sodium dodecylbenzene sulfonate; the amount of surfactant used is 5 to 20% of the mass of the dust.

5. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (3), after adding the surfactant to the digestion solution, stir for 2–6 hours to ensure complete dissolution; after adding the alkali solution, stir at 60–100 °C. o C. Stir the reaction mixture and adjust the pH of the digestion solution to 7-10 until iron, zinc and calcium are completely precipitated.

6. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (4), the filter cake is placed at 80-120°C. o Dry in an oven at temperature C for 6–24 hours.

7. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (5), the adhesive includes one or more of polyethylene oxide, guar gum powder, silica sol, glycerin, starch, boehmite, calcium oxide, and clay; the pore-forming agent includes one or more of starch, sawdust, polyvinyl alcohol, methyl methacrylate, ammonium bicarbonate, and toner; and the active additives include one or more of zinc chloride, basic zinc carbonate, γ-Al2O3, sodium carbonate, potassium carbonate, and ammonium bicarbonate.

8. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (5), by mass percentage, it includes 75-90% composite oxide dry powder, 2-15% pore-forming agent, 3-15% adhesive, 3-19% active additive, and 1-2% water.

9. The preparation method of the composite oxide desulfurizer based on iron- and zinc-containing dust and sludge according to claim 1, characterized in that, In step (5), drying involves first placing the extruded sample at room temperature for 12–24 hours, and then placing it in a container with a temperature of 60–120 °C. o Dry in a C oven for 6–24 hours.

10. The composite oxide desulfurizer prepared by the preparation method according to any one of claims 1-9.

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