Dioxin generation inhibitor prepared from copper smelting tailings and preparation method thereof
A porous Fe2O3-CuO-SiO2 composite skeleton inhibitor was prepared by copper smelting tailings, and a manganese source was added and sulfided to form a FeS2-CuS surface layer. Combined with a hydrophobic layer sol, the problems of high cost and poor stability of existing dioxin generation inhibitors were solved, and efficient inhibition of dioxin generation and resource utilization were achieved.
Patent Information
- Application Number
- CN202510787036.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2025-09-30
AI Technical Summary
Existing dioxin generation inhibitors are expensive, unstable, and pose a risk of secondary pollution, making them difficult to use on a large scale. Existing treatment methods cannot effectively solve the problem of dioxin generation and emission during high-temperature smelting processes.
Copper smelting tailings are used as raw materials. After pretreatment, functional site performance enhancement and molding treatment, a porous Fe2O3-CuO-SiO2 composite skeleton inhibitor is prepared. The FeS2-CuS surface layer is formed by adding manganese source and sulfidation treatment, and combined with the hydrophobic layer sol to make a granular inhibitor.
It achieves efficient inhibition of dioxin formation, reduces the operating costs of metallurgical plants, avoids secondary pollution, provides an economical and efficient dioxin source control strategy, and realizes the resource utilization of copper smelting tailings.
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Figure CN120714601A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of gas purification, and in particular relates to a dioxin generation inhibitor prepared from copper smelting tailings and a preparation method thereof. Background Art
[0002] With the rapid development of the global copper metallurgical industry, the stockpile volume of copper tailings, a typical solid waste, has increased year by year. Traditional treatment methods (such as landfill and stockpiling) not only occupy land resources, but may also pollute the soil, water and atmosphere through filtration, dust and other pathways, seriously threatening the ecological environment and human health. Therefore, efficient and resource-based disposal of copper tailings can tap their potential as a resource and address the harm they cause to the ecology and human health. At the same time, the generation and emission of dioxins (PCDD / Fs) during high-temperature smelting processes have attracted much attention. As persistent organic pollutants (POPs), dioxins have become a difficult issue in global environmental governance due to their high toxicity, bioaccumulation and long-range migration.
[0003] Although existing dioxin suppression technologies (such as rapid cooling, activated carbon adsorption, catalytic degradation, etc.) have certain effects, they generally have problems such as high cost, complex process or secondary pollution risk, and cannot solve the problem of dioxin release at the source. By inhibiting dioxin formation, the problem of dioxin emissions can be solved from the source. The main components of existing dioxin generation inhibitors are metal oxides (Fe2O3, CuO, CaO, etc.), nitrogen-based materials (ammonia, urea, etc.) and sulfur-containing compounds (thiourea, sulfide, etc.). Inhibitors can reduce dioxin generation by interfering with the formation of chlorinated precursors, blocking free radical chain reactions, and fixing chlorine sources. However, existing dioxin generation inhibitors are often costly, have poor stability, and have a high risk of secondary pollution, making them difficult to apply on a large scale.
[0004] Copper smelting tailings are rich in metal oxides such as iron, aluminum, and silicon, as well as quartz and feldspar minerals. These can interfere with dioxin formation pathways through adsorption, catalytic oxidation, or chlorine source fixation. Some studies suggest that Fe₂O₃ in copper smelting tailings may inhibit dioxin formation by oxidizing chlorobenzene precursors or disrupting free radical chain reactions. The porous mineral structure can adsorb gaseous chlorine, reducing the formation of chlorophenol precursors. Research is needed to develop copper smelting tailings into highly effective dioxin inhibitors. Summary of the Invention
[0005] In order to achieve the above-mentioned purpose of "using waste to treat pollution", the present invention provides a dioxin generation inhibitor made from copper smelting tailings and a preparation method thereof. The preparation method uses copper smelting tailings, and through various treatment methods such as pretreatment, functional site performance enhancement and molding, to prepare an inhibitor that can effectively inhibit dioxin generation.
[0006] The technical solutions of the present invention are as follows:
[0007] In a first aspect, the present invention provides a method for preparing a dioxin generation inhibitor from copper smelting tailings, comprising the following steps:
[0008] S1. Pretreatment of copper smelting tailings:
[0009] Under stirring conditions, copper smelting tailings are added to dilute sulfuric acid and soaked to remove heavy metals and part of carbonates in the copper smelting tailings, thereby obtaining copper smelting tailings containing only components such as Fe2O3, CuO and SiO2; after filtering, washing and drying, the tailings are calcined in a muffle furnace to obtain a porous Fe2O3-CuO-SiO2 composite skeleton inhibitor;
[0010] S2, porous Fe2O3-CuO-SiO2 composite skeleton inhibitor function enhancement modification:
[0011] The porous Fe2O3-CuO-SiO2 composite skeleton inhibitor is immersed in a Mn source solution, subjected to ultrasound, and then calcined to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at a high temperature and an H2S / N2 mixed gas is introduced to allow the H2S to react with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor having a FeS2-CuS surface layer;
[0012] S3. Formation of dioxin generation inhibitor:
[0013] The inhibitor having the FeS2-CuS surface layer is mixed with a binder, stirred evenly, and formed into a granular inhibitor by a granulator; and a hydrophobic layer sol is sprayed on the surface of the granular inhibitor to form a molded inhibitor.
[0014] The copper smelting tailings are tailings formed by low-grade minerals that are not selected after the copper ore is crushed and flotation separated, and the main components are SiO2, Al2O3 and Fe2O3.
[0015] Preferably, in step S1, the concentration of the dilute sulfuric acid is 0.3-0.6 mol / L.
[0016] Preferably, in step S1, the copper smelting tailings are soaked in dilute sulfuric acid for 1-3 hours.
[0017] Preferably, in step S1, the calcination temperature is 600-700° C., and the calcination time is 1-3 hours.
[0018] Preferably, the specific surface area of the porous Fe2O3-CuO-SiO2 composite skeleton inhibitor obtained in step S1 is 150-300m 2 / g.
[0019] Preferably, in step S2, the Mn source is one or more of Mn(NO3)2, (CH3COO)2Mn and MnCl2; the concentration of the Mn source solution is 0.4-0.7 mol / L; and the mass ratio of the porous Fe2O3-CuO-SiO2 composite skeleton inhibitor to the Mn element is 10:1-5:1.
[0020] Preferably, in step S2, the ultrasonic temperature is 50-70°C, preferably 60-65°C, and the ultrasonic time is 3-5 hours.
[0021] Preferably, in step S2, the calcination temperature is 450-600° C., and the calcination time is 1-2 hours.
[0022] Preferably, in step S2, the H2S concentration in the H2S / N2 mixed gas is 3-10%, the introduction time is 1-2 hours, and the flow rate is 100-200 mL / min.
[0023] Preferably, in step S3, the binder is one or more of bentonite, carboxymethyl cellulose, water, and montmorillonite; and the mass ratio of the binder to the inhibitor having the FeS2-CuS surface layer is 1:10-1:5.
[0024] Preferably, in step S3, the particle size of the granular inhibitor is 2-4 mm.
[0025] Preferably, in step S3, the hydrophobic layer sol is one or more of commercial titanium dioxide sol, titanium nanotube sol, silicon dioxide sol, graphene sol, and carbon nanotube sol, and the spraying thickness is 50-100 mm.
[0026] In some specific embodiments, the method for preparing a dioxin generation inhibitor from copper smelting tailings comprises the following steps:
[0027] ①Pretreatment of copper smelting tailings:
[0028] Under stirring conditions, the copper smelting tailings are added to 0.3-0.6 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, and copper smelting tailings containing only components such as Fe2O3, CuO and SiO2 are obtained; after filtering, washing and drying, the above product is calcined at 650℃ in a muffle furnace for 2 hours to obtain a specific surface area of 150-300m 2 / g porous Fe2O3-CuO-SiO2 composite skeleton inhibitor.
[0029] ② Functional enhancement modification of porous Fe2O3-CuO-SiO2 composite skeleton inhibitor:
[0030] The porous Fe2O3-CuO-SiO2 composite skeleton inhibitor is immersed in a 0.4-0.7 mol / LMn(NO3)2 solution, placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 450-600°C to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at high temperature and introduced into a H2S / N2 mixed gas (H2S concentration is 3-10%) for 1 hour, so that H2S reacts with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor with a FeS2-CuS surface layer, thereby enhancing the Cl - Capture capability.
[0031] ③ Dioxin generation inhibitor molding:
[0032] The inhibitor having a FeS2-CuS surface layer is mixed with a bentonite binder at a mass ratio of bentonite to inhibitor of 1:10-1:5, stirred evenly, and formed into a granular inhibitor by a granulator; a hydrophobic layer sol is sprayed on the surface of the granular inhibitor to a thickness of 50-100 mm to form a molded inhibitor.
[0033] In a second aspect, the present invention provides a dioxin production inhibitor prepared by the above preparation method.
[0034] This invention modifies copper smelting tailings to act as a dioxin inhibitor, utilizing the active Fe2O3 species in the tailings. Through specialized treatment methods, the tailings are transformed into a porous structure. This not only achieves high-value utilization of solid waste and reduces the burden of tailings disposal, but also provides a cost-effective new strategy for controlling dioxin pollution in industrial flue gas. This technology converts solid waste into an inexpensive material with both gas-phase inhibition and solid-phase catalysis capabilities. This material is then directly added to the incinerator's exhaust duct, achieving the dual goals of resource utilization and dioxin source control through a "waste-to-poison" approach. This provides a new direction for high-value utilization of solid waste.
[0035] The beneficial effects of the present invention are:
[0036] (1) The dioxin generation inhibitor is prepared from copper smelting tailings, realizing solid waste resource utilization and waste treatment. The proposed dioxin generation inhibitor can replace high-cost activated carbon and commercial catalysts. The proposed method for preparing dioxin generation inhibitor from copper smelting tailings not only provides a solution to the problem of land resource occupation and disposal of copper smelting tailings, but also reduces the operating costs of metallurgical plants.
[0037] (2) Adopt green modification processes such as pickling-sulfurization-molding to efficiently activate copper smelting tailings. The pickling process removes impurities such as heavy metals and inert substances on the surface of copper smelting tailings that affect the function of inhibitors. Sulfurization further optimizes the existence form and distribution characteristics of active components in copper smelting tailings, significantly improving its inhibitory performance against dioxin formation. Hydrophobic layer sol spraying can prevent water molecules in the flue gas environment from poisoning the active components in the dioxin formation inhibitor, so that the dioxin formation inhibitor can play a long-lasting and stable role. The preparation process is green and environmentally friendly, does not introduce harmful chemical reagents, and avoids secondary pollution while activating copper smelting tailings.
[0038] (3) The dioxin inhibitor is prepared using copper smelting tailings, which can efficiently utilize the Fe and Cu components in the copper smelting tailings. At the same time, the addition of manganese source impregnation can form more stable Mn-Fe-Cu ternary active metal oxide species on the inhibitor surface, thereby improving the activity of the dioxin inhibitor. The acid washing and sulfurization treatment processes are used to make the surface of the dioxin generation inhibitor have more abundant chlorine adsorption sites, thereby inhibiting the generation of chlorine-containing dioxins. The dioxin generation inhibitor can solve the problem of dioxin generation from the source. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 This is a schematic diagram of the preparation method of the dioxin generation inhibitor produced from copper smelting tailings proposed by the present invention. DETAILED DESCRIPTION
[0040] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.
[0041] The copper smelting tailings in the embodiment are tailings formed by the unselected low-grade minerals after the copper ore is crushed and flotation-separated from a copper smelting plant in Jiangxi Province, and the main components are SiO2, Al2O3 and Fe2O3.
[0042] Example 1
[0043] The preparation method of a dioxin generation inhibitor made from copper smelting tailings of this embodiment is as follows: Figure 1 As shown, the specific steps include:
[0044] (1) Under stirring conditions, 1.5 kg of copper smelting tailings were added to 2 L of 0.5 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, and copper smelting tailings containing only components such as Fe2O3, CuO and SiO2 were obtained; after filtering, washing and drying, the tailings were calcined at 650 ° C in a muffle furnace for 2 hours to obtain 1.3 kg of porous Fe2O3-CuO-SiO2 composite skeleton precursor. The porous Fe2O3-CuO-SiO2 composite skeleton precursor was characterized by low-temperature nitrogen adsorption and the specific surface area was measured to be 167 m 2 / g.
[0045] (2) The porous Fe2O3-CuO-SiO2 composite skeleton precursor is immersed in 4.8L of 0.5mol / L Mn(NO3)2 solution, placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 600°C to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at a high temperature and a 5% H2S / N2 mixed gas is introduced at a flow rate of 120mL / min for 1 hour to allow H2S to react with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor having a FeS2-CuS surface layer.
[0046] (3) The inhibitor having the FeS2-CuS surface layer was mixed with a bentonite binder in a mass ratio of 1:10, stirred evenly, and formed into a 3.5 mm granular inhibitor by a granulator; the surface of the granular inhibitor was sprayed with a commercial titanium dioxide sol (Xuancheng Jingrui New Materials Co., Ltd., VK-TA33, titanium dioxide content 15%) as a hydrophobic layer sol, with a spraying thickness of 75 mm, to form a molded inhibitor.
[0047] The performance of the dioxin generation inhibitor was evaluated in a pilot plant at a metallurgical plant with a flue gas temperature of 400°C and an initial dioxin concentration of 1.2 ng TEQ / m 3 After using 1.5 kg of the dioxin inhibitor, the dioxin concentration in the flue gas dropped to 0.02 ng TEQ / m 3 .
[0048] Example 2
[0049] (1) Under stirring conditions, 1.5 kg of copper smelting tailings were added to 2 L of 0.6 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, and copper smelting tailings containing only components such as Fe2O3, CuO and SiO2 were obtained; after filtering, washing and drying, the tailings were calcined at 650 ° C in a muffle furnace for 2 hours to obtain 1.3 kg of porous Fe2O3-CuO-SiO2 composite skeleton precursor. The obtained porous Fe2O3-CuO-SiO2 composite skeleton precursor was characterized by low-temperature nitrogen adsorption and had a specific surface area of 274 m 2 / g.
[0050] (2) The porous Fe2O3-CuO-SiO2 composite skeleton precursor is immersed in 4L, 0.6mol / L Mn(NO3)2 solution, placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 450°C to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at high temperature and a 10% H2S / N2 mixed gas is introduced at a flow rate of 150mL / min for 1 hour to allow H2S to react with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor having a FeS2-CuS surface layer.
[0051] (3) The inhibitor having the FeS2-CuS surface layer was mixed with a bentonite binder in a mass ratio of 1:5, stirred evenly, and formed into a 4 mm granular inhibitor by a granulator; the surface of the granular inhibitor was sprayed with a carbon nanotube hydrophobic layer sol (Jiangsu Xianfeng Nanomaterial Technology Co., Ltd., 1333-86-4, purity ≥95%), with a spraying thickness of 50 mm to form a molded inhibitor.
[0052] The performance of the dioxin generation inhibitor was evaluated in a pilot plant at a metallurgical plant with a flue gas temperature of 400°C and an initial dioxin concentration of 1.6 ng TEQ / m 3 After adding 1.5 kg of the dioxin inhibitor, the dioxin concentration in the flue gas dropped to 0.12 ng TEQ / m 3 .
[0053] Example 3
[0054] (1) Under stirring conditions, 1.5 kg of copper smelting tailings were added to 2 L of 0.3 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, and copper smelting tailings containing only components such as Fe2O3, CuO and SiO2 were obtained; after filtering, washing and drying, the tailings were calcined at 650 ° C in a muffle furnace for 2 hours to obtain 1.3 kg of porous Fe2O3-CuO-SiO2 composite skeleton precursor. The prepared porous Fe2O3-CuO-SiO2 composite skeleton precursor was characterized by low-temperature nitrogen adsorption and the specific surface area was measured to be 175 m 2 / g.
[0055] (2) The porous Fe2O3-CuO-SiO2 composite skeleton precursor is immersed in 7L, 0.4mol / L Mn(NO3)2 solution, placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 500°C to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at high temperature and a 10% H2S / N2 mixed gas is introduced at a flow rate of 100mL / min for 1 hour to allow H2S to react with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor having a FeS2-CuS surface layer.
[0056] (3) The inhibitor having the FeS2-CuS surface layer was mixed with a bentonite binder in a mass ratio of 1:5, stirred evenly, and formed into a 4 mm granular inhibitor by a granulator; the surface of the granular inhibitor was sprayed with a carbon nanotube hydrophobic layer sol (Jiangsu Xianfeng Nanomaterial Technology Co., Ltd., 1333-86-4, purity ≥95%), with a spraying thickness of 100 mm, to form a molded inhibitor.
[0057] The performance of the dioxin generation inhibitor was evaluated in a pilot plant at a metallurgical plant with a flue gas temperature of 400°C and an initial dioxin concentration of 1.5 ng TEQ / m 3 After adding 1.5 kg of the dioxin inhibitor, the dioxin concentration in the flue gas dropped to 0.08 ng TEQ / m 3 .
[0058] Example 4
[0059] (1) Under stirring conditions, 1.5 kg of copper smelting tailings were added to 2 L of 0.5 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, and copper smelting tailings containing only components such as Fe2O3, CuO and SiO2 were obtained; after filtering, washing and drying, the tailings were calcined at 650 ° C in a muffle furnace for 2 hours to obtain 1.3 kg of porous Fe2O3-CuO-SiO2 composite skeleton precursor. The specific surface area of the precursor was measured to be 175 m2 by low-temperature nitrogen adsorption characterization test.2 / g.
[0060] (2) The porous Fe2O3-CuO-SiO2 composite skeleton precursor is immersed in 12L, 0.4mol / L Mn(NO3)2 solution, placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 500°C to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at a high temperature and a 3% H2S / N2 mixed gas is introduced at a flow rate of 180mL / min for 1 hour to allow H2S to react with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor having a FeS2-CuS surface layer.
[0061] (3) The inhibitor having the FeS2-CuS surface layer was mixed with a bentonite binder in a mass ratio of 1:10, stirred evenly, and formed into a 2 mm granular inhibitor by a granulator; the surface of the granular inhibitor was sprayed with a graphene hydrophobic layer sol (Nanjing Jicang Nano Technology Co., Ltd., GFSP-100, carbon content ≥98%), with a spraying thickness of 60 mm to form a molded inhibitor.
[0062] The performance of the dioxin generation inhibitor was evaluated in a pilot plant at a metallurgical plant with a flue gas temperature of 400°C and an initial dioxin concentration of 1.5 ng TEQ / m 3 After adding 1.5 kg of the dioxin inhibitor, the dioxin concentration in the flue gas dropped to 0.08 ng TEQ / m 3 .
[0063] Comparative Example 1
[0064] (1) Under stirring conditions, 1.5 kg of copper smelting tailings were added to 2 L of 0.5 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, and copper smelting tailings containing only components such as Fe2O3, CuO and SiO2 were obtained; after filtering, washing and drying, the tailings were calcined at 650°C in a muffle furnace for 2 hours to obtain 1.3 kg of porous Fe2O3-CuO-SiO2 composite skeleton precursor.
[0065] (2) The porous Fe2O3-CuO-SiO2 composite skeleton precursor is placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 600°C to form a Fe-Cu ternary oxide; the Fe-Cu oxide is placed at a high temperature and a 5% H2S / N2 mixed gas is introduced at a flow rate of 120 mL / min for 1 hour to allow H2S to react with the Fe2O3-CuO component in the Fe-Cu oxide to form an inhibitor having a FeS2-CuS surface layer.
[0066] (3) The inhibitor having the FeS2-CuS surface layer was mixed with a bentonite binder in a mass ratio of 1:10, stirred evenly, and formed into a 3.5 mm granular inhibitor by a granulator; a commercial titanium dioxide sol was sprayed on the surface of the granular inhibitor as a hydrophobic layer sol (Xuancheng Jingrui New Materials Co., Ltd., VK-TA33, titanium dioxide content 15%), with a spraying thickness of 75 mm, to form a molded inhibitor without a manganese source.
[0067] The performance of the dioxin generation inhibitor was evaluated in a pilot plant at a metallurgical plant with a flue gas temperature of 400°C and an initial dioxin concentration of 1.5 ng TEQ / m 3 After adding 1.5 kg of the dioxin inhibitor without manganese source, the dioxin concentration in the flue gas dropped to 1.0 ng TEQ / m 3 .
[0068] Comparative Example 2
[0069] (1) Under stirring conditions, 1.5 kg of copper smelting tailings were added to 2 L of 0.5 mol / L dilute sulfuric acid and soaked for 2 hours to remove heavy metals and part of carbonates in the copper smelting tailings, thereby obtaining copper smelting tailings containing only components such as Fe2O3, CuO and SiO2; after filtering, washing and drying, the tailings were calcined at 650 ° C in a muffle furnace for 2 hours to obtain a porous Fe2O3-CuO-SiO2 composite skeleton precursor.
[0070] (2) The porous Fe2O3-CuO-SiO2 composite skeleton precursor was immersed in 4.8 L of 0.5 mol / L Mn(NO3)2 solution, placed in an ultrasonic cleaning machine, shaken at 60°C for 4 hours, and calcined at 600°C to form a Mn-Fe-Cu ternary oxide.
[0071] (3) The above-mentioned Mn-Fe-Cu ternary oxide and bentonite binder were mixed in a mass ratio of 1:10, stirred evenly, and formed into a 2 mm granular inhibitor by a granulator; the surface of the granular inhibitor was sprayed with commercial titanium dioxide sol as a hydrophobic layer sol (Xuancheng Jingrui New Materials Co., Ltd., VK-TA33, titanium dioxide content 15%), with a spraying thickness of 75 mm to form an uncured molding inhibitor.
[0072] The performance of the dioxin generation inhibitor was evaluated in a pilot plant at a metallurgical plant with a flue gas temperature of 400°C and an initial dioxin concentration of 1.5 ng TEQ / m 3 After adding 1.5 kg of the unsulfurized dioxin inhibitor, the dioxin concentration in the flue gas dropped to 0.85 ng TEQ / m 3 .
[0073] Comparative Example 3
[0074] The performance of a commercial activated carbon dioxin inhibitor (GH-25, Jiangsu Kaien Activated Carbon Co., Ltd.) was evaluated in a pilot plant at a metallurgical plant. The flue gas temperature was 400°C and the initial dioxin concentration in the flue gas was 1.5 ng TEQ / m 3 After adding 1.5 kg of commercial activated carbon, the dioxin concentration in the flue gas dropped to 0.52 ng TEQ / m 3 .
[0075] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered to fall within the scope of protection of the present invention.
Claims
1. A method for preparing a dioxin generation inhibitor from copper smelting tailings, characterized in that: The following steps are involved: S1. Pretreatment of copper smelting tailings: Under stirring conditions, the copper smelting tailings are added to dilute sulfuric acid and soaked to remove heavy metals and part of carbonate in the copper smelting tailings. After filtering, washing and drying, the tailings are calcined in a muffle furnace to obtain a porous Fe2O3-CuO-SiO2 composite skeleton inhibitor. S2, porous Fe2O3-CuO-SiO2 composite skeleton inhibitor function enhancement modification: The porous Fe2O3-CuO-SiO2 composite skeleton inhibitor is immersed in a Mn source solution, subjected to ultrasound, and then calcined to form a Mn-Fe-Cu ternary oxide; the Mn-Fe-Cu ternary oxide is placed at a high temperature and an H2S / N2 mixed gas is introduced to allow the H2S to react with the Fe2O3-CuO component in the Mn-Fe-Cu ternary oxide to form an inhibitor having a FeS2-CuS surface layer; S3. Formation of dioxin generation inhibitor: The inhibitor having the FeS2-CuS surface layer is mixed with a binder, stirred evenly, and formed into a granular inhibitor by a granulator; and a hydrophobic layer sol is sprayed on the surface of the granular inhibitor to form a molded inhibitor.
2. The preparation method according to claim 1, characterized in that In step S1, the concentration of the dilute sulfuric acid is 0.3-0.6 mol / L; In step S1, the copper smelting tailings are soaked in dilute sulfuric acid for 1-3 hours.
3. The preparation method according to claim 1, characterized in that In step S1, the calcination temperature is 600-700° C., and the calcination time is 1-3 hours; The specific surface area of the porous Fe2O3-CuO-SiO2 composite skeleton inhibitor obtained in step S1 is 150-300m 2 / g.
4. The preparation method according to claim 1, characterized in that In step S2, the Mn source is one or more of Mn(NO3)2, (CH3COO)2Mn and MnCl2; the concentration of the Mn source solution is 0.4-0.7 mol / L; the mass ratio of the porous Fe2O3-CuO-SiO2 composite skeleton inhibitor to the Mn element is 10:1-5:
1.
5. The preparation method according to claim 1, characterized in that In step S2, the ultrasonic temperature is 50-70°C and the ultrasonic time is 3-5 hours; In step S2, the calcination temperature is 450-600° C., and the calcination time is 1-2 hours.
6. The preparation method according to claim 1, characterized in that In step S2, the H2S concentration in the H2S / N2 mixed gas is 3-10%, the introduction time is 1-2 hours, and the flow rate is 100-200 mL / min.
7. The preparation method according to claim 1, characterized in that In step S3, the binder is one or more of bentonite, carboxymethyl cellulose, water, and montmorillonite; and the mass ratio of the binder to the inhibitor having the FeS2-CuS surface layer is 1:10-1:
5.
8. The preparation method according to claim 1, characterized in that In step S3, the particle size of the granular inhibitor is 2-4 mm.
9. The preparation method according to claim 1, characterized in that In step S3, the hydrophobic layer sol is one or more of commercial titanium dioxide sol, titanium nanotube sol, silicon dioxide sol, graphene sol, and carbon nanotube sol, and the spraying thickness is 50-100 mm.
10. A dioxin production inhibitor, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 9.
Citation Information
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