Garbage treatment method based on enhanced molten pool smelting technology

Abstract

The invention provides a garbage treatment method based on an enhanced molten pool smelting technology, which comprises the following steps: sorting to obtain garbage with a calorific value, and drying, crushing, screening and forming the obtained pretreated components to obtain solid recycled fuel; and then the solid recycled fuel is placed in an intensified molten pool smelting furnace for fusion immersion combustion treatment or replaces at least part of fossil fuel to be placed in the intensified molten pool smelting furnace together with the to-be-smelted material for smelting treatment. According to the garbage treatment method provided by the invention, not only can the generation amount of fly ash and the generation amount of leachate be effectively reduced, but also the technological process of the garbage treatment process can be shortened, so that the garbage treatment efficiency is further improved, and the garbage treatment cost is reduced. According to the method, resource utilization, energy utilization and harmless treatment of the waste garbage can be achieved, meanwhile, good economic value can be achieved, and the method has the advantages of being high in volume reduction efficiency, free of secondary hazardous waste, high in treatment efficiency, small in environmental influence, remarkable in economic benefit and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of waste treatment, and in particular to a waste treatment method based on enhanced molten pool smelting technology. Background Art

[0002] With the acceleration of urbanization, the problem of urban domestic waste treatment has become increasingly prominent. Incineration power generation technology has become the mainstream method of urban domestic waste treatment because it can quickly reduce the volume and quantity of waste, treat it harmlessly, and recover energy. Incineration power generation facilities mainly use technologies such as mechanical grate furnaces, fluidized bed incinerators and rotary kilns. Among them, mechanical grate furnaces occupy a dominant position due to their stability and processing capacity. However, secondary pollutants generated during the incineration process, such as fly ash and leachate, have become an environmental problem that needs to be solved urgently.

[0003] Fly ash, as the main byproduct of waste incineration, contains high concentrations of dioxins, heavy metals and persistent organic pollutants, and is a hazardous waste. At present, the main methods for the disposal of fly ash include chelation stabilization landfill, cement kiln co-treatment and high-temperature melting vitrification. Although chelation stabilization landfill can reduce the release of pollutants to a certain extent, the landfill site is limited and there are long-term environmental safety and management issues; cement kiln co-treatment requires complex pretreatment, such as water washing and dechlorination, which not only increases costs but also may affect the quality of cement; and although high-temperature melting vitrification can effectively solidify heavy metals, its high energy consumption and the generation of secondary fly ash are also a major challenge. Garbage leachate is a high-concentration organic wastewater generated during the storage or treatment of garbage before incineration. It has complex composition, high pollutant concentration and is extremely difficult to treat. The traditional treatment method is to treat and concentrate the leachate in the incineration site and then spray it back into the incinerator. This practice results in excessively high salt content in the incineration ash, which increases the difficulty of subsequent treatment and resource utilization. At the same time, high-salt wastewater corrodes the grate furnace and flue gas treatment equipment, affecting the operating efficiency and stability of the incinerator. Finding a simple and convenient method to reduce the generation of fly ash and leachate during garbage disposal and reduce the cost of garbage disposal has become the current development direction of garbage disposal.

[0004] The development of solid recovered fuel (SRF) has opened up a new way for the energy utilization of municipal solid waste. SRF is a new type of fuel prepared by drying and sorting municipal solid waste. Compared with traditional refuse-derived fuel (RDF), SRF has stricter production standards and complies with ISO's standardized classification and specifications, ensuring the stability and environmental performance of the fuel. In addition, SRF has a high calorific value and a low content of chlorine-containing pollutants, which is conducive to achieving efficient and clean combustion, reducing negative impacts on the environment, and reducing greenhouse gas emissions. It is a renewable energy option to replace fossil fuels.

[0005] Based on the above technical background, there is an urgent need to find a method that can effectively reduce the amount of secondary pollutants such as fly ash and leachate generated in the waste incineration process, realize the resource utilization, energy utilization and harmless treatment of urban domestic waste, aiming to reduce the cost of waste disposal, resource utilization of waste, reduce dependence on fossil fuels, and be environmentally friendly. Summary of the invention

[0006] The main purpose of the present invention is to provide a waste treatment method based on enhanced molten pool smelting technology to reduce the amount of secondary pollutants such as fly ash and leachate generated during waste incineration. The treatment method aims to reduce the cost of waste treatment, reduce the generation of pollutants, realize the resource utilization, energy utilization and harmless treatment of waste, and also have good economic value.

[0007] The garbage treatment method based on enhanced molten pool smelting technology provided by the present invention comprises the following steps: pretreatment: sorting the garbage to obtain pretreated components with calorific value, the pretreated components with calorific value comprising: paper product garbage, wood product garbage and plastic product garbage; preparing solid recovered fuel: drying, crushing, screening and molding the pretreated components to obtain solid recovered fuel; wherein the net calorific value of the solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine in the solid recovered fuel is ≤3%; enhanced molten pool smelting furnace treatment: placing the solid recovered fuel in an enhanced molten pool smelting furnace for molten immersion combustion treatment; or, placing the solid recovered fuel, fossil fuel and the material to be smelted in an enhanced molten pool smelting furnace for smelting treatment; obtaining glassy slag.

[0008] Furthermore, the temperature of the molten immersion combustion treatment is 1100-1400°C; preferably, the temperature of the smelting treatment is 1000-1700°C.

[0009] Furthermore, the solid recovered fuel meets the SRF product quality standard-international standard ISO 21640:2021; preferably, the oxygen volume concentration of the enhanced molten pool smelting furnace is ≥25%; preferably, the enhanced molten pool smelting furnace is equipped with a stirring medium spray gun, which is used to spray stirring medium into the molten pool of the enhanced molten pool smelting furnace; preferably, the stirring medium is at least one of oxygen, oxygen-enriched air with an oxygen volume concentration ≥25%, oxygen and solid recovered fuel, and oxygen-enriched air with an oxygen volume concentration ≥25% and solid recovered fuel; preferably, the spray gun is located at least one of the bottom, top and side of the enhanced molten pool smelting furnace; preferably, the solid recovered fuel is sprayed into the enhanced molten pool smelting furnace as a stirring medium through the spray gun, and / or, the solid recovered fuel is added to the enhanced molten pool smelting furnace through the feeding inlet of the enhanced molten pool smelting furnace; preferably, the solid recovered fuel is at least one of block, columnar, flocculent or granular.

[0010] Furthermore, the time of the molten immersion combustion treatment is 0.5 to 2 hours; preferably, the time of the smelting treatment is 1 to 4 hours; preferably, during the smelting treatment, the weight ratio of the solid recovered fuel to the fossil fuel is (1 to 50): (50 to 100).

[0011] Furthermore, the enhanced molten pool smelting furnace is at least one of an SRF molten submerged combustion furnace, a zinc leaching slag melting furnace, a copper slag reduction furnace, a high-lead slag reduction furnace and a waste lead-acid battery lead paste reduction furnace; preferably, the material to be smelted is at least one of zinc leaching slag, copper slag, high-lead slag and waste lead-acid battery lead paste.

[0012] Furthermore, the pretreatment process also includes: sorting out glass materials and sand containing SiO2 and / or Al2O3 as slag-forming flux; preferably, the slag-forming flux is added during the molten immersion combustion process or the smelting process.

[0013] Furthermore, when the molten immersion combustion treatment is carried out, the weight ratio of the solid recovered fuel to the slag-forming flux is (50-100):(1-50); and / or, when the smelting treatment is carried out, the original ingredients for enhanced smelting in the enhanced molten pool smelting furnace include: materials to be smelted, fossil fuels and slag-forming flux, and the mass ratio of the solid recovered fuel to the original ingredients for enhanced smelting is (1-50):100.

[0014] Furthermore, the particle size of the garbage components after the crushing process is 3 to 8 mm.

[0015] Furthermore, the drying temperature is 60 to 150° C., and the drying time is 0.5 to 2.0 h.

[0016] Furthermore, the molten immersion combustion treatment and smelting treatment process will produce fly ash, which is returned to the enhanced molten pool smelting furnace for waste treatment; preferably, the glassy slag is used as a building material; preferably, the heat generated during the molten immersion combustion treatment process is used to generate electricity or heat domestic water.

[0017] The present invention provides a waste treatment method based on enhanced molten pool smelting technology, in which the waste with calorific value is first obtained by sorting, and then the obtained pre-treated components are dried, crushed, screened and formed to obtain solid recovered fuel; the obtained solid recovered fuel is then used for molten immersion combustion treatment or replaced at least part of the fossil fuel and placed together with the material to be smelted in an enhanced molten pool smelting furnace for smelting treatment. In the waste treatment method based on enhanced molten pool smelting technology provided by the present invention, it is possible to realize the resource utilization, energy utilization and harmless treatment of waste garbage, and it can also have good economic value. First, the solid recovered fuel that meets the standards is obtained after the waste garbage is treated, and the chlorine content is at a low level, which can not only effectively reduce the harmful gases such as dioxins generated in the waste treatment process, but also effectively decompose the organic matter that is difficult to decompose. In addition, the above-mentioned pretreatment method can also reduce the amount of garbage leachate generated in the waste treatment process, reducing the cost of further treating the leachate. Secondly, the enhanced molten pool smelting furnace is used to treat the garbage. The enhanced molten pool smelting furnace has the advantages of fast heat and mass transfer speed, and decomposes at a higher temperature, which can effectively reduce the amount of fly ash generated, and there is no need to further collect and treat the generated fly ash. Thirdly, compared with the traditional method of incinerating garbage, which requires the use of a grate furnace and a fly ash harmless treatment device to complete the garbage treatment, the method of using the enhanced molten pool smelting furnace provided by the present invention to treat garbage can only use the enhanced molten pool smelting furnace to complete the garbage treatment process. The method provided by the present invention can shorten the process of garbage treatment, further improve the garbage treatment efficiency, and reduce the cost of garbage treatment. In addition, the reduction of the chlorine content in the pretreatment components after pretreatment of the waste garbage can further reduce the corrosion of the enhanced molten pool smelting furnace, which is beneficial to extend the service life of the enhanced molten pool smelting furnace.

[0018] In summary, the waste treatment method based on enhanced molten pool smelting technology provided by the present invention converts waste domestic waste into solid recycled fuel, and then uses enhanced molten pool smelting technology to treat it, which not only avoids the generation of secondary pollutants, but also realizes efficient utilization of resources, and has the advantages of high volume reduction efficiency, no secondary hazardous waste, high treatment efficiency, small environmental impact, and significant economic benefits. At the same time, the shortening of the waste treatment process can also further reduce the cost of waste treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram of the process of the waste treatment method based on the enhanced molten pool smelting technology proposed by the present invention;

[0021] Figure 2 A schematic diagram of an enhanced molten pool smelting furnace according to Example 1 of the present invention is shown, wherein the above-mentioned figure includes the following figure marks: 1. charging port; 2. smoke outlet; 3. liquid level line; 4. spray gun hole; 5. slag outlet. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] How to effectively reduce secondary pollutants such as fly ash and leachate generated by waste incineration and realize the resource and energy utilization and harmless treatment of urban domestic waste is a problem that needs to be solved urgently.

[0024] In order to solve the above problems, the present invention proposes a garbage treatment method based on enhanced molten pool smelting technology, which comprises the following steps: pretreatment: sorting the garbage to obtain pretreated components with calorific value, the pretreated components with calorific value include: paper product garbage, wood product garbage and plastic product garbage; preparing solid recovered fuel: drying, crushing, screening and molding the pretreated components to obtain solid recovered fuel; wherein the net calorific value of the solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine in the solid recovered fuel is ≤3%; enhanced molten pool smelting furnace treatment: placing the solid recovered fuel in an enhanced molten pool smelting furnace for molten immersion combustion treatment; or, placing the solid recovered fuel, fossil fuel and the material to be smelted in an enhanced molten pool smelting furnace for smelting treatment; obtaining glassy slag.

[0025] In the process of the above waste treatment, the collected waste is first sorted to obtain waste with calorific value (such as paper products, wood products, plastic products, etc.), and hazardous waste (such as discarded batteries, etc.) and waste without calorific value (such as metal products) are removed to obtain pre-treatment components. The obtained pre-treatment components are then dried, crushed, screened and formed to obtain solid recovered fuel; wherein the net calorific value of the solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine in the solid recovered fuel is ≤3%. Finally, the solid recovered fuel prepared above is placed in an enhanced molten pool smelting furnace for treatment: the solid recovered fuel is placed in an enhanced molten pool smelting furnace for molten immersion combustion treatment; or, the solid recovered fuel, fossil fuel and the material to be smelted are placed in an enhanced molten pool smelting furnace for smelting treatment; both treatment methods can eventually obtain glassy slag.

[0026] The above-mentioned waste treatment process includes two treatment methods: first, placing the solid recovered fuel in an enhanced molten pool smelting furnace for molten immersion combustion treatment. This treatment method can collect the heat generated during the combustion of the solid recovered fuel for power generation, heating, etc., which not only achieves the purpose of treating waste, but also can realize the reuse of resources in the waste treatment process. Second, placing the solid recovered fuel, fossil fuel and the material to be smelted in an enhanced molten pool smelting furnace for smelting treatment. On the one hand, this treatment method can treat waste, and on the other hand, it can also be used to replace part of the fossil fuel to provide heat and participate in the metal smelting process. The above-mentioned use of the obtained solid recovered fuel for molten immersion combustion treatment or replacing at least part of the fossil fuel and the material to be smelted in the enhanced molten pool smelting furnace for smelting treatment can also obtain glassy slag. The obtained glassy slag can be used to produce microcrystalline glass, glass fiber and the like for building decoration materials, and can also be used as a road material for paving roadbeds and other purposes (process as shown in the figure). Figure 1 shown).

[0027] The garbage treatment method based on the enhanced molten pool smelting technology provided by the present invention can realize the resource utilization, energy utilization and harmless treatment of waste garbage, and also has good economic value. First, the waste garbage is sorted, dried, crushed and screened to obtain solid recycled fuel that meets the standards. The chlorine content in the obtained solid recycled fuel is at a low level. While effectively decomposing the organic matter that is difficult to decompose, it can also reduce the harmful gases such as dioxins generated during the garbage treatment process. In addition, the above-mentioned pretreatment method can also reduce the amount of garbage leachate generated during the garbage treatment process, reducing the cost of further treating the leachate. Second, the garbage is treated with an enhanced molten pool smelting furnace. The enhanced molten pool smelting furnace has the advantages of fast heat and mass transfer speed, and decomposes at a higher temperature, especially it can effectively reduce the amount of fly ash generated, and there is no need to further collect and treat the generated fly ash. Third, compared with the traditional method of incinerating garbage, which requires the use of a grate furnace and a fly ash harmless treatment device (such as a fly ash high-temperature melting furnace) to complete the garbage treatment process, the method of treating garbage using an enhanced molten pool smelting furnace provided by the present invention can complete the garbage treatment process using only an enhanced molten pool smelting furnace, which can effectively shorten the garbage treatment process, improve garbage treatment efficiency, and reduce garbage treatment costs. In addition, the reduction in the chlorine content in the pretreatment components after pretreatment of the waste garbage can further reduce the corrosion of the enhanced molten pool smelting furnace, which is beneficial to extend the service life of the enhanced molten pool smelting furnace. The formed glassy slag can be used as a building material, further improving the resource efficiency of the waste garbage. The above advantages can effectively reduce the cost of garbage treatment.

[0028] In summary, the waste treatment method based on enhanced molten pool smelting technology provided by the present invention converts urban domestic waste into solid recovery fuel, and then uses enhanced molten pool smelting technology for treatment, which not only avoids the generation of secondary pollutants (such as fly ash and leachate), but also realizes efficient utilization of resources, and has the advantages of high volume reduction efficiency, no secondary hazardous waste, high treatment efficiency, small environmental impact, and significant economic benefits. At the same time, the shortening of the waste treatment process can further reduce the cost of waste treatment.

[0029] In a preferred embodiment, the temperature of the melt immersion combustion treatment is 1100-1400°C, specifically 1100°C, 1200°C, 1300°C, 1400°C or any temperature between any two of the above values. When the prepared solid recovered fuel is melt immersion combustion treated, the temperature is controlled at 1100-1400°C, which can not only further reduce the generation of fly ash and harmful gases such as dioxins, but also make the formed glassy slag of better quality, making it more conducive to use as a building material.

[0030] Preferably, the temperature of the smelting treatment is 1000-1700°C, specifically 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, 1600°C, 1700°C or any temperature between any two of the above values. When the solid recovered fuel obtained from garbage treatment replaces part of the fossil fuel and is placed in the enhanced molten pool smelting furnace together with the material to be smelted for smelting treatment, the temperature of the smelting treatment is controlled to be 1000-1700°C, which can not only reduce the use of fossil fuels, but also achieve the purpose of treating waste garbage; further, the heat generated by the combustion of the solid recovered fuel can be further used for the smelting treatment of the material to be smelted. The specific temperature of smelting can be determined according to the smelting temperature required by the metal to be smelted in the smelting process. Controlling the smelting temperature within the above range can further reduce the generation of fly ash and harmful gases such as dioxins, and can also make the quality of the recovered glassy slag better.

[0031] In a preferred embodiment, the solid recovered fuel (SRF) meets the SRF product quality standard - international standard ISO 21640:2021. Controlling the prepared solid recovered fuel to meet the SRF product quality standard can further reduce the amount of harmful substances generated in the waste treatment process. Preferably, the oxygen volume concentration of the enhanced molten pool smelting furnace is ≥25%, specifically 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any concentration between any two of the above values. Controlling the oxygen volume concentration in the enhanced molten pool smelting furnace within the above range can make the solid recovered fuel burn more fully. Preferably, the enhanced molten pool smelting furnace is equipped with a stirring medium spray gun, which is used to spray a stirring medium into the molten pool of the enhanced molten pool smelting furnace; preferably, the stirring medium is at least one of oxygen, oxygen-enriched air with an oxygen volume concentration ≥25%, oxygen and solid recovered fuel, and oxygen-enriched air with an oxygen volume concentration ≥25% and solid recovered fuel. The above-mentioned stirring medium is injected through a spray gun, and the high-speed jet characteristics of the spray gun can make the stirring medium fully stir the molten pool, further improving the heat and mass transfer efficiency and chemical reaction process of the molten pool smelting furnace. Among them, when oxygen and solid recovered fuel or oxygen-enriched air with an oxygen volume concentration of ≥25% and solid recovered fuel are used as stirring media, the system reaction can be carried out more fully.

[0032] Preferably, the spray gun is located at least one of the bottom, top and side of the enhanced molten pool smelting furnace. The enhanced molten pool smelting furnace is equipped with a stirring medium spray gun that can play the role of stirring, heat transfer and mass transfer by blowing stirring medium. Using the above stirring medium and setting the spray gun in the above manner can make the effect of molten immersion combustion treatment or smelting treatment better. Preferably, solid recovered fuel is sprayed into the enhanced molten pool smelting furnace through a spray gun as a stirring medium; and / or, the solid recovered fuel is added to the enhanced molten pool smelting furnace through the feeding inlet of the enhanced molten pool smelting furnace. Preferably, the solid recovered fuel is at least one of block, columnar, flocculent or granular. Both of the above-mentioned feeding methods for solid recovered fuel are acceptable. In particular, when the solid recovered fuel is flocculent or granular, the solid recovered fuel can be better sprayed into the enhanced molten pool smelting furnace through a spray gun as a stirring medium, which can make the solid recovered fuel treatment more sufficient.

[0033] In a preferred embodiment, the time of the molten immersion combustion treatment is 0.5 to 2 hours; preferably, the time of the smelting treatment is 1 to 4 hours. Controlling the time of the molten immersion combustion treatment and the time of the smelting treatment within the above range can not only fully decompose and transform the waste garbage and avoid residual harmful substances, but also control the treatment cycle, improve the turnover rate of the treatment facilities, and further reduce the cost of waste treatment. Preferably, during the smelting treatment, the weight ratio of solid recovered fuel to fossil fuel is (1 to 50): (50 to 100). In the process of using solid recovered fuel to replace part of the fossil fuel and placing it together with the material to be smelted in the enhanced molten pool smelting furnace for smelting treatment, controlling the ratio of solid recovered fuel to fossil fuel within the above range can achieve the purpose of treating the waste garbage, and can also have sufficient heat supply, so that the material to be smelted can have good quality, further reducing the use of fossil fuels.

[0034] In a preferred embodiment, the enhanced molten pool smelting furnace is at least one of an SRF molten submerged combustion furnace, a zinc leaching slag melting furnace, a copper slag reduction furnace, a high-lead slag reduction furnace, and a waste lead-acid battery lead paste reduction furnace; the present invention has no special requirements for the enhanced molten pool smelting furnace, and the above is only an example. It is not difficult for those skilled in the art to understand that the molten pool smelting furnace in the field of non-ferrous metallurgy can be used as an enhanced molten pool smelting furnace in the garbage treatment method based on the enhanced molten pool smelting technology provided by the present invention. Preferably, the material to be smelted is at least one of zinc leaching slag, copper slag, high-lead slag, and waste lead-acid battery lead paste. The solid recovered fuel prepared in the garbage treatment method based on the enhanced molten pool smelting technology proposed in the present invention can meet the above-mentioned temperature requirements. The garbage treatment process can not only realize the recycling of waste garbage resources, but also further realize efficient waste metal recovery, and fully realize the resource utilization of waste garbage.

[0035] In a preferred embodiment, the pretreatment process further includes: sorting out glass materials and sand containing SiO2 and / or Al2O3 as slag-forming flux; preferably, the above-mentioned slag-forming flux is added in the molten immersion combustion process or the smelting process. The glass materials and sand containing SiO2 and / or Al2O3 sorted out in the sorting process are reused as slag-forming flux in the immersion combustion process and the smelting process, which can effectively reduce the use of slag-forming flux. The waste components in the waste recycling garbage can also be further utilized, which is conducive to further improving the recycling efficiency of the waste garbage and reducing the smelting cost. Preferably, when the molten immersion combustion treatment is carried out, the weight ratio of solid recovered fuel to slag-forming flux is (50-100): (1-50); and / or, when the smelting treatment is carried out, the mass ratio of solid recovered fuel to original ingredients for enhanced smelting is (1-50): 100, wherein the original ingredients for enhanced smelting include materials to be smelted, fossil fuels and slag-forming solvents. Controlling the weight ratio of the solid recovered fuel to the slag-forming flux within the above ranges can achieve better effects of the molten submerged combustion process and the smelting process.

[0036] In a preferred embodiment, the particle size of the garbage component after the crushing process is 3 to 8 mm. Controlling the particle size of the garbage component after the crushing process within the above range can further improve the quality of the solid recovered fuel, make it easier to shape, and enable more uniform combustion and more efficient release of heat energy, which is conducive to further improving the utilization efficiency of the solid recovered fuel.

[0037] In a preferred embodiment, the drying temperature is 60-150° C. and the drying time is 0.5-2.0 h. The drying process is beneficial to remove moisture from the pretreated components, further improve the calorific value and combustion efficiency of the solid recovered fuel, and improve the energy utilization rate of the solid recovered fuel.

[0038] The molten immersion combustion treatment and smelting treatment process will produce fly ash. In a preferred embodiment, the generated fly ash is returned to the enhanced molten pool smelting furnace for waste treatment. The method proposed in the present invention for molten immersion combustion treatment and smelting treatment of waste garbage using an enhanced molten pool smelting furnace can not only greatly reduce the amount of fly ash generated, but also directly return the small amount of fly ash generated to the enhanced molten pool smelting furnace for waste treatment. Compared with the methods of treating fly ash in the prior art by chelating stable coupling landfill treatment, cement kiln co-treatment and high-temperature molten vitrification treatment, the method for treating fly ash proposed in the present invention has a short process, low cost, simple and convenient operation, and does not require additional collection and treatment, and can effectively avoid the secondary pollution, explosion and other dangers that may be caused by the storage of fly ash. Preferably, the glassy slag is used as a building material; preferably, the heat generated during the molten immersion combustion treatment process is used to generate electricity or heat domestic water. Using glassy slag as a building material realizes the resource utilization and building material utilization of waste slag, reduces waste emissions, and at the same time, uses the heat generated by the molten immersion combustion process to generate electricity or supply domestic hot water, further improving energy utilization efficiency and increasing economic benefits.

[0039] By way of example and not limitation, Figure 2 A schematic diagram of the enhanced molten pool smelting furnace used in Example 1 is given. In actual application, solid recovered fuel can be added to the enhanced molten pool smelting furnace through the feeding port 1 for molten immersion combustion treatment; or, solid recovered fuel, fossil fuel and the material to be smelted are added to the enhanced molten pool smelting furnace through the feeding port 1 for smelting treatment. The feeding amount is controlled below the liquid level line 3 to avoid blockage of the feeding port 1 caused by splashing, which affects continuous operation; the jet medium sprayed from the spray gun hole 4 located in the bottom direction of the enhanced molten pool smelting furnace can be oxygen-enriched air and / or solid recovered fuel. While providing a reaction medium for the reaction of the system, the jet medium can also fully stir the reaction materials in the enhanced molten pool smelting furnace, so that the heat and mass transfer in the system is more uniform and the waste treatment is more sufficient. In addition, solid recovered fuel can also be sprayed into the enhanced molten pool smelting furnace through a spray gun, which can play the above-mentioned stirring and mixing role while adding solid recovered fuel thereto. A small amount of fly ash generated during the treatment process of the enhanced molten pool smelting furnace can be discharged from the smoke outlet 2 to the outside of the enhanced molten pool smelting furnace for collection, and the glassy slag generated during the treatment process of the enhanced molten pool smelting furnace can be collected through the slag outlet 5 for use as building materials.

[0040] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0041] Example 1

[0042] Pretreatment: sort out waste such as paper products, wood products, plastic products, etc. to obtain pretreatment components; at the same time, separate glass materials and sand and gravel as slag-making flux;

[0043] Preparation of solid recovered fuel: drying the pretreated components at 100°C for 1 hour, crushing them to obtain particles with a particle size of 3 to 8 mm, and then screening and molding them to obtain granular solid recovered fuel; the net calorific value of the obtained solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine is ≤3%, meeting the SRF product quality standard-international standard ISO 21640:2021;

[0044] Enhanced molten pool smelting furnace treatment: the solid recovered fuel and fossil fuel coal obtained above are added into the enhanced molten pool smelting furnace through the feeding port in a weight ratio of 50:100 for smelting treatment, and oxygen-enriched air is introduced into the enhanced molten pool smelting furnace by spraying through the nozzle of the spray gun. Among them, the enhanced molten pool smelting furnace is a zinc leaching slag melting furnace with bottom blowing, side blowing and top blowing equipment, the oxygen volume content in the oxygen-enriched air is 60%, and the materials to be smelted are zinc leaching slag and zinc oxide ore. The temperature in the enhanced molten pool smelting furnace is 1400°C, the smelting treatment time is 3h, and the mass ratio of solid recovered fuel to the original ingredients of enhanced smelting (materials to be smelted, fossil fuels and slag-making flux) is 1:100. After the above smelting treatment, glassy slag is obtained, and the obtained glassy slag can be recycled as a building material for further use;

[0045] Fly ash treatment: The fly ash generated by the above waste treatment process is returned to the zinc leaching slag melting furnace for waste treatment.

[0046] Example 2

[0047] Pretreatment: sort out waste such as paper products, wood products, plastic products, etc. to obtain pretreatment components; at the same time, separate glass materials and sand and gravel as slag-making flux;

[0048] Preparation of solid recovered fuel: drying the pretreated components at 60°C for 2h, crushing them to obtain particles with a particle size of 3 to 8mm, and then screening and molding them to obtain granular solid recovered fuel; the net calorific value of the obtained solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine is ≤3%, meeting the SRF product quality standard-international standard ISO 21640:2021;

[0049] Enhanced molten pool smelting furnace treatment: The above-obtained slag-forming flux and the above-obtained solid recovered fuel are mixed in a weight ratio of 50:1 and added into the enhanced molten pool smelting furnace through the feeding port and the spray gun nozzle for molten immersion combustion treatment, and oxygen-enriched air is introduced into the enhanced molten pool smelting furnace through the spray gun nozzle. Among them, the enhanced molten pool smelting furnace is an SRF molten immersion combustion furnace with bottom blowing, side blowing and top blowing equipment, the oxygen volume content in the oxygen-enriched air is 30%, the temperature in the enhanced molten pool smelting furnace is 1100°C, the molten immersion combustion treatment time is 2h, and the heat generated during the molten immersion combustion treatment is used to heat domestic water. After the above-mentioned smelting treatment, glassy slag is obtained, and the obtained glassy slag can be recycled and further used as a building material;

[0050] Fly ash treatment: The fly ash generated by the above waste treatment process is returned to the SRF molten submerged combustion furnace for waste treatment.

[0051] Example 3

[0052] Pretreatment: sort out waste such as paper products, wood products, plastic products, etc. to obtain pretreatment components; at the same time, separate glass materials and sand and gravel as slag-making flux;

[0053] Preparation of solid recovered fuel: drying the pretreated components at 150°C for 0.5h, crushing them to obtain particles with a particle size of 3 to 8mm, and then screening and molding them to obtain block solid recovered fuel; the net calorific value of the obtained solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine is ≤3%, meeting the SRF product quality standard-international standard ISO 21640:2021;

[0054] Enhanced molten pool smelting furnace treatment: the solid recovered fuel obtained above is added into the enhanced molten pool smelting furnace through the feeding port for molten immersion combustion treatment, and oxygen-enriched air is introduced into the enhanced molten pool smelting furnace by spraying through the nozzle of the spray gun. Among them, the enhanced molten pool smelting furnace is an SRF molten immersion combustion furnace with bottom blowing, side blowing and top blowing equipment, the oxygen volume content in the oxygen-enriched air is 60%, the temperature in the enhanced molten pool smelting furnace is 1400°C, the molten immersion combustion treatment time is 0.5h, and the heat generated during the molten immersion combustion treatment is used for power generation. After the above smelting treatment, glassy slag is obtained, and the obtained glassy slag can be recycled and further used as a building material;

[0055] Fly ash treatment: The fly ash generated by the above waste treatment process is returned to the SRF molten submerged combustion furnace for waste treatment.

[0056] Example 4

[0057] Pretreatment: sort out waste such as paper products, wood products, plastic products, etc. to obtain pretreatment components; at the same time, separate glass materials and sand and gravel as slag-making flux;

[0058] Preparation of solid recovered fuel: drying the pretreated components at 100°C for 1 hour, crushing them to obtain particles with a particle size of 3 to 8 mm, and then screening and molding them to obtain granular solid recovered fuel; the net calorific value of the obtained solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine is ≤3%, meeting the SRF product quality standard-international standard ISO 21640:2021;

[0059] Strengthened molten pool smelting furnace treatment: The solid recovered fuel and fossil fuel coal obtained above are added to the strengthened molten pool smelting furnace through the feeding port in a weight ratio of 50:50 for smelting treatment, and oxygen-enriched air is introduced into the strengthened molten pool smelting furnace through the spray gun port. Among them, the strengthened molten pool smelting furnace is a waste lead-acid battery lead paste reduction furnace with bottom blowing, side blowing and top blowing equipment, the oxygen volume content in the oxygen-enriched air is 80%, the material to be smelted is waste lead-acid battery lead paste, the temperature in the strengthened molten pool smelting furnace is 1200℃, the smelting treatment time is 2h, and the mass ratio of solid recovered fuel to the original ingredients of the strengthened smelting (material to be smelted, fossil fuel and slag-making flux) is 50:100. After the above smelting treatment, glassy slag is obtained, and the obtained glassy slag can be recycled as a building material for further use.

[0060] Fly ash treatment: The fly ash generated by the above waste treatment process is returned to the lead paste reduction furnace for waste removal.

[0061] Example 5

[0062] Pretreatment: sort out waste such as paper products, wood products, plastic products, etc. to obtain pretreatment components; at the same time, separate glass materials and sand and gravel as slag-making flux;

[0063] Preparation of solid recovered fuel: drying the pretreated components at 100°C for 1 hour, crushing them to obtain particles with a particle size of 3 to 8 mm, and then screening and molding them to obtain granular solid recovered fuel; the net calorific value of the obtained solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine is ≤3%, meeting the SRF product quality standard-international standard ISO 21640:2021;

[0064] Enhanced molten pool smelting furnace treatment: the solid recovered fuel and fossil fuel coal obtained above are added into the enhanced molten pool smelting furnace through the feeding port in a weight ratio of 1:100 for smelting treatment, and oxygen-enriched air is introduced into the enhanced molten pool smelting furnace by spraying through the nozzle of the spray gun. Among them, the enhanced molten pool smelting furnace is a copper slag reduction furnace with bottom blowing, side blowing and top blowing equipment, the oxygen volume content in the oxygen-enriched air is 60%, the material to be smelted is copper slag, the temperature in the enhanced molten pool smelting furnace is 1300°C, the smelting treatment time is 2h, and the mass ratio of solid recovered fuel to the original ingredients of enhanced smelting (material to be smelted, fossil fuel and slag-making flux) is 50:100. After the above smelting treatment, glassy slag is obtained, and the obtained glassy slag can be recycled as a building material for further use;

[0065] Fly ash treatment: The fly ash generated by the above waste treatment process is returned to the copper slag reduction furnace for waste treatment.

[0066] Example 6

[0067] The difference between Example 6 and Example 2 is that the temperature of the melt immersion combustion treatment is 900°C.

[0068] Comparative Example 1

[0069] Comparative Example 1 uses a grate furnace to treat garbage.

[0070] Garbage reception and storage: The garbage is weighed by the scale and unloaded into the garbage bin. The garbage in the garbage bin is mixed and stirred by a grab bucket. Leachate will be produced during the storage of the garbage in the garbage bin, and the leachate produced is collected.

[0071] Grate furnace waste incineration: The garbage crane delivers the mixed and stirred garbage into the feed hopper and then into the mechanical grate incinerator, where it burns at 850-1100°C. The high-temperature flue gas generated by the combustion passes through the natural circulation boiler to generate high-temperature steam, which is used for heating or to drive the steam turbine generator set to generate electricity. The burned slag falls into the slag discharge device, and after cooling, it is transported to the brick factory for use. The fly ash generated is collected in the fly ash harmless treatment device.

[0072] Fly ash and leachate treatment system: The fly ash collected by the fly ash harmless treatment device (semi-dry flue gas purification device) is hazardous waste and is landfilled after high-temperature melting and harmless treatment; the leachate is concentrated and then sprayed back to the incinerator for further treatment.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Comparative Example 1 is that the incineration process adopts fluidized bed equipment.

[0075] The amount of fly ash generated when treating waste in Examples 1 to 6 and Comparative Examples 1 and 2 was statistically analyzed, and the results are shown in Table 1. The fly ash generation ratio refers to the ratio of the amount of fly ash generated / the amount of waste treated × 100%; the leachate generation ratio refers to the ratio of the amount of filtrate generated / the amount of waste treated × 100%. When the glass content of the glassy slag is ≥ 85%, its quality is defined as good; when the glass content is < 85%, its quality is defined as poor.

[0076] Table 1

[0077]

[0078] It should be further explained here that the “ / ” in the “quality of glassy slag” in Table 1 means that the method of the corresponding embodiment cannot produce glassy slag.

[0079] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0080] (I) Realizing the resource utilization of waste

[0081] The solid recycled fuel is placed in an enhanced molten pool smelting furnace for molten immersion combustion treatment, which can collect the heat generated during the combustion of the solid recycled fuel for power generation, heating, etc., which not only achieves the purpose of treating waste, but also can realize the reuse of resources in the waste treatment process;

[0082] The method of placing solid recycled fuel, fossil fuel and materials to be smelted together in an enhanced molten pool smelting furnace for smelting can, on the one hand, treat waste garbage, and on the other hand, can also be used to replace part of the fossil fuels to provide heat and participate in the metal smelting process.

[0083] The solid recovered fuel is used for molten immersion combustion or replaces at least part of the fossil fuel and is placed in an enhanced molten pool smelting furnace with the material to be smelted for smelting, and glassy slag can be obtained, which can be further utilized as a building material. The above method realizes the resource utilization, energy utilization and harmless treatment of urban domestic waste to the greatest extent, while reducing the use of fossil fuels in the smelting process, further reducing production costs, being environmentally friendly and having high economic value.

[0084] (II) Reduce the amount of waste fly ash and leachate generated

[0085] The above two methods of treating garbage proposed in the present invention can also avoid secondary pollutants such as fly ash and leachate generated by traditional garbage incineration, and have the advantages of complete volume reduction, no secondary hazardous waste generation, high efficiency, high degree of resource and energy utilization, environmental friendliness, good economic benefits, etc. In addition, the above garbage treatment method based on enhanced molten pool smelting technology produces less secondary fly ash, and a small amount of secondary fly ash and smoke is mixed with the silica flux screened out by SRF preparation pretreatment and granulated and returned to the furnace to achieve maximum resource utilization, heavy metals enter the glassy slag and are solidified, and no secondary pollutants are discharged.

[0086] (III) Reduce the generation of harmful gases

[0087] In the enhanced molten pool smelting furnace, under the action of oxygen enrichment and spray gun jet stirring, the heat and mass transfer and chemical reactions in the furnace are very fast and violent. The high temperature environment can avoid the production of dioxins in the traditional domestic waste incineration process. At the same time, the above-mentioned treatment process reacts thoroughly and can fully decompose the persistent and difficult-to-decompose organic matter in domestic waste and fly ash.

[0088] (IV) Reducing the cost of waste treatment equipment in many ways

[0089] The waste treatment method based on the enhanced molten pool smelting technology provided by the present invention has a small amount of fly ash generated, and a single enhanced molten pool smelting furnace device can achieve the functions that can only be achieved by two devices, the traditional garbage incineration grate furnace and the fly ash high-temperature melting furnace, without the need to build a fly ash harmless treatment device, which effectively optimizes the waste treatment process. In addition, the enhanced molten pool smelting furnace described in the present invention has a strong type selectivity, and the existing more mature SRF molten immersion combustion furnace, zinc leaching slag melting furnace, copper slag reduction furnace, high-lead slag reduction furnace, and waste lead-acid battery lead paste reduction furnace and other molten pool smelting furnaces in the non-ferrous metallurgy field can be realized, which is easy to implement in engineering.

[0090] In addition, before the waste is prepared into SRF, it first undergoes pre-treatment operations such as sorting and screening to control the calorific value and chlorine content of the SRF to meet international standards. Therefore, the salt and chlorine content of the SRF raw materials can be greatly reduced, avoiding corrosion to the furnace and waste heat boiler of the enhanced molten pool smelting furnace.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for treating waste based on enhanced molten pool smelting technology, characterized in that: The processing method comprises the following steps: Pretreatment: sorting the garbage to obtain pretreatment components with calorific value, wherein the pretreatment components with calorific value include: paper product garbage, wood product garbage and plastic product garbage; Preparation of solid recovered fuel: drying, crushing, screening and molding the pretreated components to obtain the solid recovered fuel; wherein the net calorific value of the solid recovered fuel is ≥3MJ / kg, and the weight content of chlorine in the solid recovered fuel is ≤3%; Enhanced molten pool smelting furnace treatment: placing the solid recovered fuel in an enhanced molten pool smelting furnace for molten immersion combustion treatment; or, placing the solid recovered fuel, fossil fuel and the material to be smelted together in an enhanced molten pool smelting furnace for smelting treatment; obtaining glassy slag.

2. The method for treating waste based on enhanced molten pool smelting technology according to claim 1, characterized in that: The temperature of the melt immersion combustion treatment is 1100-1400°C; Preferably, the temperature of the smelting treatment is 1000-1700°C.

3. The method for treating waste based on enhanced molten pool smelting technology according to claim 1, characterized in that: The solid recovered fuel meets the SRF product quality standard - international standard ISO 21640:2021; Preferably, the oxygen volume concentration of the enhanced molten pool smelting furnace is ≥25%; Preferably, the enhanced molten pool smelting furnace is equipped with a stirring medium spray gun, which is used to spray a stirring medium into the molten pool of the enhanced molten pool smelting furnace; preferably, the stirring medium is at least one of oxygen, oxygen-enriched air with an oxygen volume concentration of ≥25%, the oxygen and the solid recovered fuel, and the oxygen-enriched air with an oxygen volume concentration of ≥25% and the solid recovered fuel; Preferably, the lance is located at least one of the bottom, top and side of the enhanced molten pool smelting furnace; Preferably, the solid recycled fuel is sprayed into the enhanced molten pool smelting furnace through the spray gun as the stirring medium, and / or the solid recycled fuel is added into the enhanced molten pool smelting furnace through the charging inlet of the enhanced molten pool smelting furnace; Preferably, the solid recovered fuel is in at least one of block, columnar, flocculent or granular form.

4. The method for treating waste based on enhanced molten pool smelting technology according to any one of claims 1 to 3, characterized in that: The time of the molten immersion combustion treatment is 0.5 to 2 hours; Preferably, the smelting treatment time is 1 to 4 hours; Preferably, during the smelting process, the weight ratio of the solid recovered fuel to the fossil fuel is (1-50): (50～100)。 5. The method for treating waste based on enhanced molten pool smelting technology according to any one of claims 1 to 3, characterized in that: The enhanced molten pool smelting furnace is at least one of an SRF molten submerged combustion furnace, a zinc leaching slag melting furnace, a copper slag reduction furnace, a high-lead slag reduction furnace, and a waste lead-acid battery lead paste reduction furnace; Preferably, the material to be smelted is at least one of zinc leaching slag, copper slag, high-lead slag and lead paste of waste lead-acid batteries.

6. The method for treating waste based on enhanced molten pool smelting technology according to any one of claims 1 to 3, characterized in that: The pretreatment process also includes: sorting out glass materials containing SiO2 and / or Al2O3 and sand and stone as slag-making flux; Preferably, the slag-forming flux is added during the molten immersion combustion process or the smelting process.

7. The method for treating waste based on enhanced molten pool smelting technology according to claim 6, characterized in that: When the molten submerged combustion treatment is performed, the weight ratio of the solid recovered fuel to the slag-forming flux is (50-100):(1-50); Preferably, when the smelting treatment is carried out, the original ingredients for enhanced smelting in the enhanced molten pool smelting furnace include: the material to be smelted, the fossil fuel and the slag-forming flux, and the mass ratio of the solid recovered fuel to the original ingredients for enhanced smelting is (1-50):

100.

8. The method for treating waste based on enhanced molten pool smelting technology according to any one of claims 1 to 3, characterized in that: The particle size of the garbage components after the crushing process is 3 to 8 mm.

9. The method for treating waste based on enhanced molten pool smelting technology according to any one of claims 1 to 3, characterized in that: The drying temperature is 60-150° C., and the drying time is 0.5-2.0 h.

10. The method for treating waste based on enhanced molten pool smelting technology according to any one of claims 1 to 3, characterized in that: The molten submerged combustion treatment and the smelting treatment process will generate fly ash, and the generated fly ash is returned to the enhanced molten pool smelting furnace for waste treatment; Preferably, the glassy slag is used as a building material; Preferably, the heat generated during the molten submerged combustion process is used to generate electricity or heat domestic water.

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