Treatment method and application of iron-containing oil sludge and waste incineration fly ash

Abstract

The invention relates to the technical field of solid waste treatment, and particularly discloses a treatment method and application of iron-containing oil sludge cooperating with waste incineration fly ash. According to the method, the high-calcium component in the garbage fly ash is used as a demulsifier, and effective separation of the iron-containing oil sludge oil-water-solid mixture is realized. A progressive circulating closed heating technology is further adopted, according to the component characteristics of the two solid wastes, low-medium-high temperature segmented temperature control is utilized, and optimized feeding compatibility is combined. According to the invention, efficient degradation of dioxin is realized, clean fuel gas is generated in a medium-temperature section and is fed back to a treatment process as a heat source, and recycling of resources is realized. Meanwhile, high-calcium and high-iron components are converted into high-quality iron-based materials, and resource utilization of hazardous waste is achieved. According to the method, the valuable high-quality iron-based material and the clean fuel gas are prepared from the two kinds of dangerous solid organic waste, efficient treatment of the two kinds of dangerous organic waste is achieved in a harmless and recycling mode, and the purpose of treating waste with waste is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid waste treatment, and in particular relates to a treatment method and application of iron-containing oil sludge in conjunction with waste incineration fly ash. Background Art

[0002] Ferrous sludge is an organic hazardous waste generated during the steel rolling process in the steel industry, while waste incineration fly ash is a dioxin-containing hazardous waste generated by the incineration of municipal waste. Ferrous sludge and waste incineration fly ash are rich in calcium and iron components, but traditional treatment methods have difficulty effectively utilizing these components. Organic pollutants such as dioxins not only harm the environment but also significantly restrict their treatment and disposal. Direct landfill and incineration are traditional methods for treating fly ash and sludge, respectively. While simple and capable of handling large volumes, they cannot effectively degrade refractory organic matter and heavy metals, and some toxic and hazardous substances still pose long-term environmental risks. In particular, the complex oil-water-solid three-phase structure and high oil content of ferrous sludge mean that direct reuse can damage steelmaking equipment. Therefore, a suitable treatment method is needed to simultaneously achieve oil-water-solid three-phase separation in ferrous sludge and effectively treat toxic and hazardous substances in fly ash and sludge. The current pyrolysis technology is unable to achieve complete degradation of dioxins, which not only affects the safe treatment of fly ash, but also restricts the feasibility of its resource utilization. Summary of the Invention

[0003] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and provide a method and application for the treatment of iron-containing oil sludge in conjunction with waste incineration fly ash. This method achieves deep degradation of dioxins and oil-containing components in the iron-containing oil sludge, generates clean gas that can replace fossil fuels in the combustion process, and synthesizes high-quality iron-based materials, thereby realizing the harmless treatment and resource utilization of hazardous organic pollutants through the coordinated treatment of iron-containing oil sludge and chemical components of waste incineration fly ash and progressive cycle closed heating technology.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] The first aspect of the present invention is to provide a method for treating iron-containing oil sludge in conjunction with waste incineration fly ash, the method comprising the following steps:

[0006] The waste incineration fly ash and iron-containing oil sludge are mixed in a certain proportion; the mixture is treated by circulating heating, and the mixture is dried, and dioxins are efficiently enriched and degraded at low temperatures in the low temperature zone of 100℃ to 300℃; the resource conversion of the oil-containing phase is achieved in the medium temperature zone of 350-500℃ to obtain clean gas, which is recycled into the heating process to reduce processing energy consumption; and the deep degradation of dioxins is achieved in the high temperature zone of 900℃ to 1300℃, while high-quality iron-based materials are synthesized.

[0007] Furthermore, the iron content of the iron-containing sludge is not less than 45%, the oil content is not less than 48%, the solid content is not less than 29%, and the density is 0.90g / cm 3 ~0.92g / cm 3 .

[0008] Furthermore, the calcium content in the waste incineration fly ash is not less than 40%, and the particle size is less than 100 μm.

[0009] Furthermore, the mixture of waste incineration fly ash and iron-containing oil sludge satisfies a molar ratio of CaO to SiO2 of 1.8 to 2.2, a molar ratio of Ca to Fe of 0.2 to 0.5, and a molar ratio of Al2O3 to SiO2 of 0.1 to 0.2.

[0010] Furthermore, the mixture of waste incineration fly ash and iron-containing oil sludge satisfies a molar ratio of CaO to SiO2 of 2, a molar ratio of Ca to Fe of 0.5, and a molar ratio of Al2O3:SiO2 of 0.1.

[0011] Furthermore, the treatment process in the low temperature zone of 100°C to 300°C is as follows: microwave heating treatment for 30min to 60min under nitrogen / argon atmosphere to achieve drying of the mixture and effective degradation of dioxins accumulated in the oil phase.

[0012] Furthermore, the moisture content of the mixture is not greater than 5%.

[0013] Furthermore, the treatment process in the medium temperature zone of 300℃~500℃ is as follows: in nitrogen / argon atmosphere, oxygen-deficient O2 concentration is less than 3%, microwave heating treatment is carried out for 20min~40min, the resource conversion of the oil-containing phase is realized, clean gas is obtained, and the gas is recycled to the heating process.

[0014] Furthermore, the treatment process in the high temperature zone of 900°C to 1300°C is as follows: O2 concentration is 5% to 20%, microwave heating time is 10min to 30min, deep degradation of dioxins, solidification of heavy metals and generation of carbon-fixing materials are achieved.

[0015] The second aspect of the present invention is to provide the application of the above method in preparing high-quality iron-based materials.

[0016] Furthermore, the main component of the high-quality iron-based material is any one of monocalcium ferrite, dicalcium ferrite, and calcium ferrite.

[0017] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0018] (1) The present invention provides a method for treating iron-containing oil sludge in conjunction with waste incineration fly ash. This method uses the high calcium component in the waste fly ash as a "demulsifier" to achieve effective separation of the oil-water-solid mixture of iron-containing oil sludge. Further, a progressive cycle closed heating technology is adopted, and based on the composition characteristics of the two solid wastes, low-medium-high temperature segmented temperature control is utilized, combined with optimized feed compatibility. Not only is the efficient degradation of dioxins achieved, but clean fuel gas is also generated in the medium temperature section and fed back into the treatment process as a heat source, achieving the recycling of resources. At the same time, high calcium and iron components are converted into high-quality iron-based materials, achieving the resource utilization of hazardous waste. This full-process progressive temperature control technology not only significantly improves the treatment efficiency, but also achieves the goal of energy conservation and emission reduction by reducing energy consumption and recovering heat energy. This innovative method not only achieves the harmless treatment of hazardous waste, but also promotes the effective utilization of resources, contributes to the "dual carbon" policy, and provides strong support for the sustainable development of the steel industry and the municipal industry.

[0019] (2) The present invention utilizes the principle of “like dissolves like” and achieves the complete degradation of dioxins in the waste incineration fly ash by synergistically treating iron-containing oil sludge and waste incineration fly ash, thereby generating resource-based products.

[0020] (3) The present invention achieves efficient degradation of organic pollutants (iron-containing sludge oil-containing components, dioxins) and generation of clean gas through progressive cycle closed heating technology, and synthesizes high-quality iron-based materials, thereby achieving harmless treatment and resource utilization of hazardous waste.

[0021] (4) The present invention utilizes two types of hazardous solid organic wastes to prepare valuable high-quality iron-based materials and clean fuel gas, achieving efficient treatment of the two types of organic hazardous wastes in a harmless and resource-based manner, and achieving the goal of "treating waste with waste." BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic flow chart of a method for treating iron-containing oil sludge in conjunction with waste incineration fly ash provided by the present invention. DETAILED DESCRIPTION

[0023] To make the objects, technical solutions, and advantages of the present invention more apparent, the following describes the specific embodiments of the present invention in further detail with reference to the specific examples and accompanying drawings. Where specific test methods, instruments, or conditions are not specified in the examples, the methods or conditions described in the literature in the art or the product specifications were used. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0024] The present invention provides a method for treating iron-containing oil sludge in conjunction with waste incineration fly ash. The method comprises mixing iron-containing oil sludge and waste incineration fly ash in a certain proportion, and utilizing progressive cycle closed heating technology to perform harmless treatment on the mixed liquid. The obtained mixed liquid is filtered, dried, and cooled to obtain clean fuel and high-quality iron-based materials that can be used in the combustion process.

[0025] Among them, iron-containing sludge has an iron content of not less than 45% and a density of 0.90g / cm3 to 0.92g / cm3. 3 , which comes from the emulsion system produced in the rolling mill section during the long process of converter-refining-rolling in steel enterprises; the waste incineration fly ash has a calcium content of not less than 40% and a particle size of less than 100μm, and comes from the larger particles deposited on the bottom of the incinerator and on the grate during the incineration of municipal domestic waste and the fine particles that enter the flue gas purification system together with the flue gas.

[0026] The mixture of waste incineration fly ash and iron-containing oil sludge must satisfy a molar ratio of CaO to SiO2 of 1.8 to 2.2, a molar ratio of Ca to Fe of 0.2 to 0.5, and a molar ratio of Al2O3 to SiO2 of 0.1 to 0.2. Preferably, the molar ratio of CaO to SiO2 is 2, the molar ratio of Ca to Fe is 0.5, and the molar ratio of Al2O3 to SiO2 is 0.1.

[0027] The low temperature zone achieves drying of the mixture, efficient enrichment and low temperature degradation of dioxins, which means that at a temperature of 100°C to 300°C, under a nitrogen / argon inert atmosphere, microwave heating is performed using a microwave heating device for 30min to 60min to achieve drying of the mixture (moisture content <5%) and effective degradation of dioxins enriched in the oil phase; the medium temperature zone achieves resource conversion of the oil phase to obtain clean fuel gas, which is recycled to the heating process, and reduces processing energy consumption, which means that at a temperature of 350-500°C, under a nitrogen / argon inert atmosphere, fuel gas is burned by combustion. The device achieves efficient pyrolysis of the emulsified oil and produces clean fuel gas, which is then recycled to the burner via a gas purification, collection, and transmission device. The high-temperature zone achieves deep degradation of dioxins and the simultaneous synthesis of high-quality iron-based materials. Microwave heating at 900°C to 1300°C for 10 to 30 minutes is used to efficiently degrade dioxins in the mixture. Cooling is then performed via a solid product rapid cooling and waste heat recovery device, and the gaseous particulate matter generated during the heating process is collected. This not only achieves deep degradation of dioxins, but also simultaneously synthesizes a high-quality iron-based material primarily composed of calcium ferrite. Structural confirmation confirmed that the prepared high-iron-based material is primarily composed of monocalcium ferrite, dicalcium ferrite, or calcium ferrite.

[0028] Example 1

[0029] Iron-containing oil sludge and waste incineration fly ash are mixed at a specific mass ratio, such that the mixture has an n(CaO):n(SiO) ratio of 2, a Ca:Fe molar ratio of 0.5, and an Al2O3:SiO2 molar ratio of 0.1. A high-pressure mixer is used for uniform mixing. A progressively closed heating furnace is then used to conduct the reaction in the low-temperature zone at 300°C for 30 minutes. The reaction is then conducted in the medium-temperature zone at 500°C for 20 minutes, with the generated gas collected and reused in the current reaction process. Finally, the reaction is conducted in the high-temperature zone at 1300°C for 10 minutes. The resulting clean fuel gas produced in the medium-temperature zone is primarily composed of methane and hydrogen, while the solid produced in the high-temperature zone is a high-quality iron-based material primarily composed of dicalcium ferrite, with a mass fraction of 89.9%.

[0030] Example 2

[0031] Iron-containing oil sludge and waste incineration fly ash are mixed at a specific mass ratio, such that the mixture has an n(CaO):n(SiO) ratio of 2.2, a Ca:Fe molar ratio of 0.5, and an Al2O3:SiO2 molar ratio of 0.1. A high-pressure mixer is used for uniform mixing, and a progressively closed heating furnace is used for reaction in the low-temperature zone of 100°C for 60 minutes. Next, the reaction is carried out in the medium-temperature zone at 350°C for 40 minutes, with the generated gas collected and reused in the current reaction process. Finally, the reaction is carried out in the high-temperature zone at 1000°C for 20 minutes. The resulting clean fuel gas produced in the medium-temperature zone is primarily composed of methane and hydrogen, while the solid produced in the high-temperature zone is a high-quality iron-based material primarily composed of monocalcium ferrite, with a mass fraction of 86.3%.

[0032] Example 3

[0033] Iron-containing oil sludge and waste incineration fly ash are mixed in a specific mass ratio to achieve a n(CaO):n(SiO) ratio of 2, a Ca:Fe molar ratio of 0.2, and an Al2O3:SiO2 molar ratio of 0.2. A high-pressure mixer is used for uniform mixing. A progressively closed heating furnace is then used for reaction in the low-temperature zone of 200°C for 60 minutes. Next, the reaction is carried out in the medium-temperature zone of 500°C for 40 minutes, with the generated gas collected and reused in the current reaction process. Finally, the reaction is carried out in the high-temperature zone of 1200°C for 15 minutes. The resulting clean fuel gas produced in the medium-temperature zone is primarily composed of methane and hydrogen, while the solid produced in the high-temperature zone is a high-quality iron-based material composed primarily of monocalcium ferrite and iron oxide, with the mass fraction of monocalcium ferrite being 41.6% and the mass fraction of iron oxide being 50.0%.

[0034] Example 4

[0035] Iron-containing oil sludge and waste incineration fly ash are mixed at a specific mass ratio to achieve a n(CaO):n(SiO) ratio of 2.2, a Ca:Fe molar ratio of 0.2, and an Al2O3:SiO2 molar ratio of 0.2. A high-pressure mixer is used for uniform mixing. A progressively closed heating furnace is then used for reaction in the low-temperature zone at 300°C for 40 minutes. The reaction is then continued in the medium-temperature zone at 350°C for 30 minutes, with the generated gas collected and reused in the current reaction process. Finally, the reaction is continued in the high-temperature zone at 1000°C for 30 minutes. The resulting clean fuel gas produced in the medium-temperature zone is primarily composed of methane and hydrogen, while the solid produced in the high-temperature zone is a high-quality iron-based material composed primarily of calcium ferrite, iron oxide, and calcium oxide. The mass fraction of calcium ferrite is 42.0%, and the mass fraction of iron oxide is 50.4%.

[0036] Example 5

[0037] Iron-containing oil sludge and waste incineration fly ash are mixed at a specific mass ratio to achieve a n(CaO):n(SiO) ratio of 1.8, a Ca:Fe molar ratio of 0.2, and an Al2O3:SiO2 molar ratio of 0.2. A high-pressure mixer is used for uniform mixing. A progressively closed heating furnace is then used for reaction in the low-temperature zone at 300°C for 60 minutes. The reaction is then continued in the medium-temperature zone at 500°C for 40 minutes, with the generated gas collected and reused in the current reaction process. Finally, the reaction is continued in the high-temperature zone at 900°C for 10 minutes. The resulting clean fuel gas produced in the medium-temperature zone is primarily composed of methane and hydrogen, while the solid produced in the high-temperature zone is a high-quality iron-based material composed primarily of monocalcium ferrite and a portion of calcium aluminosilicate. The mass percentage of monocalcium ferrite is 72.1%, while the mass percentage of calcium aluminosilicate is 27%.

[0038] Comparative Example 1

[0039] Iron-containing oil sludge and waste incineration fly ash were mixed at a specific mass ratio to achieve a n(CaO):n(SiO) ratio of 0.1, a Ca:Fe molar ratio of 1, and an Al2O3:SiO2 molar ratio of 1. A high-pressure mixer was used for uniform mixing. A progressively closed heating furnace was then used for reaction in the low-temperature zone of 50°C for 60 minutes. The reaction was then continued in the medium-temperature zone of 200°C for 40 minutes. Finally, the reaction was continued in the high-temperature zone of 500°C for 10 minutes. The resulting medium-temperature zone produced no clean gas, and some of the oil phase (such as emulsified oil and other organic matter) was not fully cracked, nor was dioxin degradation. The solids produced in the high-temperature zone of the system consisted of a mixture of 30.6% calcium aluminosilicate, 20.0% calcium ferrite, 14.4% calcium oxide, 10.0% iron oxide, 6.7% silicon oxide, 3.3% aluminum oxide, and 15% hydrocarbons and oil.

[0040] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for treating iron-containing oil sludge in conjunction with waste incineration fly ash, characterized in that: The processing method comprises the following steps: The waste incineration fly ash and iron-containing oil sludge are mixed in a certain proportion; the mixture is treated by circulating heating, and the mixture is dried, and dioxins are efficiently enriched and degraded at low temperatures in the low temperature zone of 100℃ to 300℃; the resource conversion of the oil-containing phase is achieved in the medium temperature zone of 350-500℃ to obtain clean gas, which is recycled into the heating process to reduce processing energy consumption; and the deep degradation of dioxins is achieved in the high temperature zone of 900℃ to 1300℃, while high-quality iron-based materials are synthesized.

2. The processing method according to claim 1, characterized in that The iron content of the iron-containing oil sludge is not less than 45%, the oil content is not less than 48%, the solid content is not less than 29%, and the density is 0.90g / cm 3 ~0.92g / cm 3 .

3. The processing method according to claim 1, characterized in that The calcium content of the waste incineration fly ash is not less than 40%, and the particle size thereof is less than 100 μm.

4. The processing method according to claim 1, wherein The mixture of waste incineration fly ash and iron-containing oil sludge satisfies the following conditions: the molar ratio of CaO to SiO2 is 1.8-2.2, the molar ratio of Ca to Fe is 0.2-0.5, and the molar ratio of Al2O3 to SiO2 is 0.1-0.

2.

5. The processing method according to claim 4, characterized in that The mixture of waste incineration fly ash and iron-containing oil sludge satisfies the following conditions: the molar ratio of CaO to SiO2 is 2, the molar ratio of Ca to Fe is 0.5, and the molar ratio of Al2O3 to SiO2 is 0.

1.

6. The processing method according to claim 1, wherein The treatment process in the low temperature zone of 100° C. to 300° C. is as follows: microwave heating treatment for 30 min to 60 min in a nitrogen / argon atmosphere.

7. The processing method according to claim 1, characterized in that The treatment process in the medium temperature zone of 300° C. to 500° C. is as follows: in a nitrogen / argon atmosphere, with an oxygen-deficient O2 concentration of less than 3%, microwave heating treatment is performed for 20 min to 40 min.

8. The processing method according to claim 1, wherein The treatment process in the high temperature zone of 900° C. to 1300° C. is as follows: the O2 concentration is 5% to 20%, and the microwave heating time is 10 minutes to 30 minutes.

9. The processing method according to claim 6, characterized in that The moisture content of the mixture is not more than 5%.

10. Use of the method according to any one of claims 1 to 9 in preparing high-quality iron-based materials, characterized in that: The main component of the high-quality iron-based material is any one of monocalcium ferrite, dicalcium ferrite and calcium ferrite.

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