Method for utilizing waste incineration fly ash and iron tailings

Abstract

The application belongs to the field of solid waste resource, and particularly relates to a method for utilizing waste incineration fly ash and iron tailings. The method for utilizing waste incineration fly ash and iron tailings comprises the following steps: mixing waste incineration fly ash with fine-milled iron tailings, and then performing a smelting reduction reaction to obtain iron alloy, geopolymer material block and secondary fly ash. The waste incineration fly ash and the iron tailings are treated at high temperature, and the heavy metal oxides in the fly ash and the iron oxides in the iron tailings are reduced to metal iron and heavy metals, respectively. The iron grade of the iron alloy can reach more than 95%, and the recovery rate can reach more than 90%. The volatile heavy metals are chlorinated and enter the secondary fly ash. In addition, the amorphous geopolymer material mainly composed of silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron is obtained. The application not only realizes detoxification of the waste incineration fly ash, but also realizes high-value resource utilization of the waste incineration fly ash and the iron tailings.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of solid waste resource utilization, and particularly relates to a utilization method of waste incineration fly ash and iron tailings. BACKGROUND

[0002] Waste incineration fly ash is a byproduct of the process of incinerating household garbage. In recent years, the incineration of household garbage has developed rapidly in China, and the amount of waste incineration fly ash will inevitably increase with the increase of the scale and capacity of household garbage incineration. The amount of waste incineration fly ash in 2022 has reached 100 million tons. With the continuous improvement of flue gas purification level, the fine particles captured by the flue gas purification system, i.e. household garbage incineration fly ash (hereinafter referred to as "fly ash"), becomes more and more "dirty". Because it is rich in heavy metals and dioxin pollutants which are highly toxic, it is listed as hazardous waste, and the treatment of fly ash has always been the focus and key link in pollution control and risk management of incineration plants.

[0003] At present, waste incineration fly ash is mainly landfilled by solidification and stabilization, but landfill not only occupies a large amount of land, but also the long-term effectiveness of the solidification and stabilization of heavy metals and dioxins in fly ash needs to be constantly verified, and most importantly, many useful substances in fly ash have not been effectively utilized, so it is urgent to develop a high-clean resource utilization method for waste incineration fly ash.

[0004] Iron tailings are waste after beneficiation, and are the main component of industrial solid waste. According to incomplete statistics, the tailings and waste rocks discharged worldwide each year are more than 10 billion tons. There are more than 8,000 state-owned mines and more than 110,000 township collective mines in China, with nearly 5 billion tons of tailings stored, and more than 500 million tons of tailings discharged annually, of which 150 million tons of iron tailings are discharged annually by black metallurgical mines. Since the valuable iron has been mostly extracted, the remaining material has a relatively low utilization rate, and most of it is stored in tailings ponds. Not only does the storage occupy a large amount of land, but also the tailings pond is a dangerous source and poses a safety risk. Once an accident occurs, it will affect the life safety of the surrounding residents. Therefore, it is necessary to develop a comprehensive utilization method for iron tailings to realize the essential safety of tailings ponds through resource utilization of iron tailings. SUMMARY

[0005] The purpose of the present application is to provide a utilization method of waste incineration fly ash and iron tailings. The present application utilizes the useful components in waste incineration fly ash and iron tailings, and prepares iron alloy, geopolymer material and secondary fly ash through co-melting reduction process, thereby completely realizing the resource utilization of waste incineration fly ash and iron tailings, achieving the purpose of waste control with waste, and providing a brand-new resource utilization path for the comprehensive utilization of waste incineration fly ash and iron tailings.

[0006] The utilization method of waste incineration fly ash and iron tailings of the present application adopts the following technical scheme:

[0007] A method for utilizing waste incineration fly ash and iron tailings, comprising the following steps: mixing the waste incineration fly ash with the finely ground iron tailings, and then performing a smelting reduction reaction to obtain an iron alloy, a geopolymer material block, and secondary fly ash.

[0008] Preferably, the mass percentage of the iron tailings is 20-80%, and the mass percentage of the waste incineration fly ash is 20-80%.

[0009] Preferably, the finely ground iron tailings are obtained by the following steps: grinding the iron tailings at a grinding concentration of 55-70% for 5-25 min, and then finely grinding the iron tailings to a size of not less than 80% of -150 μm.

[0010] Preferably, the smelting reduction reaction is performed by the following steps: mixing the waste incineration fly ash with the finely ground iron tailings, and then placing the mixture in a crucible, and placing the crucible in a muffle furnace to perform a smelting reduction at 1050-1300 °C for 30-180 min. During the smelting reduction, the iron alloy gathers to form iron alloy large particles with a particle size of not less than 5 mm and located at the bottom of the smelting product due to the difference in density between the iron alloy and the slag. After natural cooling or water quenching, the smelting product is taken out of the crucible, and the iron alloy large particles naturally fall off from the smelting product. The remaining smelting product with glass characteristics is the geopolymer material block.

[0011] Preferably, the smelting reduction reaction is performed by the following steps: mixing the waste incineration fly ash with the finely ground iron tailings, and then placing the mixture in a smelting furnace to perform a smelting reduction at 1050-1300 °C for 30-180 min. Then, the iron alloy liquid flows out from the tapping hole at the bottom of the smelting furnace, and the slag liquid flows out from the slag tapping hole of the smelting furnace. After natural cooling or water quenching, the slag is obtained as the geopolymer material block.

[0012] Preferably, during the smelting reduction reaction, a flue gas trapping device is used to trap the flue gas to obtain secondary fly ash, which is a mixture of NaCl 10-80%, KCl 10-80%, PbCl2 1-10%, ZnCl2 1-10%, and CdCl2 0-10%.

[0013] Further preferably, before the smelting reduction reaction, the waste incineration fly ash, the finely ground iron tailings, and an additive are mixed, the mass percentage of the additive is 0-10%, and the additive is sodium carbonate or / and aluminum oxide.

[0014] Further preferably, the geopolymer material block is finely ground to a mass fraction of -45 µm of ≥70% and a specific surface area of ≥400 m 2 / kg, namely, amorphous polymer material composed of silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron, wherein the glass substance content is greater than or equal to 90%; the compressive strength of the mixture of the amorphous polymer material with a mass fraction of 70-95% and cement with a mass fraction of 5-30% is greater than or equal to 70 MPa, and the flexural strength is greater than or equal to 6 MPa after 28 days.

[0015] Further preferably, the mass percentage of main elements of the waste incineration fly ash is as follows: Ca 10-60%, C 5-20%, Si 0.1-10%, Al 0.1-8%, Cl 10-30%, Fe 0.1-8%, Na 0.1-6%, K 0.1-6%, S 0.1-3%, Zn 0-1%, Pb 0-1%, Cr 0-1%, Cu 0-1%, Ni 0-1%, and Cd 0-1%.

[0016] Further preferably, the mass percentage of main elements of the iron tailings is as follows: Fe2O3 5-25%, SiO2 25-70%, Al2O3 5-25%, CaO 2-20%, and MgO 2-10%.

[0017] Beneficial effects:

[0018] The waste incineration fly ash is a system with high calcium, high chlorine and high carbon, and trace heavy metals in the form of oxides or sulfides; the iron tailings are mainly composed of magnetite, augite and quartz, and are a system with high iron, high silicon and a certain amount of aluminum. The waste incineration fly ash and the iron tailings are treated at high temperature, the carbon in the waste incineration fly ash reacts with CO2

[0019] The reaction generates CO, which provides a reducing agent for the reduction reaction; meanwhile, carbon can also directly participate in the reduction reaction. The heavy metal oxides (such as Cu, Ni, Cr, etc.) in the waste incineration fly ash, the magnetite in the iron tailings, and the iron oxides in the augite are reduced to metallic iron and other metals under a high-temperature reducing atmosphere, realizing the reduction of the metal-containing minerals in the system. Compared with the reduction process using coal, coke, etc. as the reducing agent for the iron tailings, the present application uses carbon in the fly ash as the reducing agent, saves carbon resources, has a lower high-temperature melting and reduction reaction temperature, and has lower energy consumption, thereby saving carbon resources and realizing energy saving and emission reduction. The contents of Na and K in the waste incineration fly ash are relatively high, and the content of SiO2 in the iron tailings is very high. The high content of SiO2 can control the melting point of the SiO2-Al2O3-CaO slag phase system, and, in combination with the effects of the alkaline metals Na and K, the melting point of the system is reduced to 1050-1300 DEG C, and the system is completely in a liquid state. The process has a lower temperature than the direct melting temperature of the waste incineration fly ash; compared with the direct reduction process for the iron tailings and iron ore using additives such as sodium carbonate and fluorite, no additives are needed, and resources can be saved. And the high content of Si can also reduce the viscosity of the system. In the low-viscosity liquid phase system, iron particles can quickly gather into large-size iron particles and gather in the lower part of the liquid phase system, while the slag phase with a smaller specific gravity gathers in the upper part, so that the large-size iron particles and the slag phase are layered due to the difference in specific gravity. At the same time, the large-size iron particles form an alloy with the heavy metals with ferrophilic properties, and the iron grade in the iron alloy can reach more than 95%, and the iron recovery rate reaches more than 90%, realizing the recovery of the ferrophilic heavy metals in the waste incineration fly ash and the iron in the iron tailings. At the same time, compared with the metallic iron obtained by reduction in the direct reduction of the iron tailings and refractory iron ore, the iron alloy obtained by the present application has a higher iron grade and contains Cu, Ni, Cr, etc., and has a higher added value. (3) The SiO2-Al2O3-CaO-FeO system reaches a molten state, and after cooling, a non-crystalline geopolymer material mainly composed of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra is obtained. 70-95% of the non-crystalline geopolymer material is mixed with 5-30% of cement to prepare a cementitious material, and the 28-day compressive strength is > 70 Mpa, and the flexural strength is > 6 Mpa, which can completely replace cement. In the cementation process of the non-crystalline geopolymer material and cement, the silicon-oxygen bonds and aluminum-oxygen bonds in the non-crystalline geopolymer material are broken and reorganized under the catalytic action of the alkalinity of the cement, forming new silicon (aluminum or phosphorus) oxygen tetrahedron structures, which is a geopolymer polymerization process, and finally a hardened product mainly composed of non-crystalline substances containing silicon (aluminum or phosphorus) oxygen tetrahedron unit structures is obtained.

[0020] (4) The dioxins in the waste incineration fly ash will be decomposed to generate CO2, H2O, HCl and other inorganic substances at 750 DEG C, losing toxicity, while the melting temperature of the present application is 1100 DEG C, which can completely decompose dioxins. The present application uses a flue gas capture system to capture secondary fly ash, and heavy metals such as Zn, Pb and Cd are chlorinated with chlorine-containing compounds in fly ash to form chlorides and volatilize into secondary fly ash. Through the flue gas capture, the secondary fly ash mainly composed of NaCl, KCl, PbCl2, ZnCl2 and CdCl2 is obtained, in which the grade of Pb and Zn reaches more than 4%, which can be used as raw materials for industrial Pb and Zn; iron-loving heavy metals such as Cu, Ni and Cr can form alloys with metal iron to be recovered, so that the fly ash detoxification and the recovery of valuable metals in the fly ash are realized at the same time through the process. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Flow chart of the embodiment of the present application;

[0022] Figure 2 XRD pattern of the iron alloy in Example 1;

[0023] Figure 3 XRD pattern of the geopolymer material block in Example 1;

[0024] Figure 4 XRD pattern of the secondary fly ash in Example 1;

[0025] Figure 5 Schematic diagram of the bottom of the smelting furnace. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0027] Example 1

[0028] A method for utilizing waste incineration fly ash and iron tailings, comprising the following steps:

[0029] (1) The iron tailings are ball milled in a ball mill at a grinding concentration of 60% for 10 min, and finely ground to 91% of -150 μm.

[0030] (2) Mix 20% waste incineration fly ash, 60% iron tailings, 7% sodium carbonate and 3% alumina evenly and put them into a crucible. Place the crucible in a muffle furnace and calcine and reduce it at 1050℃ for 180 min. Then remove the crucible from the muffle furnace and cool it with water. Then, put the crucible into an oven and dry it at 70℃ for 20 min. After drying, take out the product from the crucible. During the removal process, the ferroalloy spheres fall off from the geopolymer material block and separate, obtaining alloy iron and geopolymer material block. The test results show that the iron grade in the ferroalloy is 95.31%, the iron recovery rate is 90.12%, and it contains trace amounts of iron-loving metals such as Ni, Cu and Cr.

[0031] (3) During the roasting and reduction process, the secondary fly ash is collected by the flue gas collection system to obtain a mixture of secondary fly ash containing 48.26% NaCl, 37.71% KCl, 5.12% PbCl2, 4.72% ZnCl2 and 1.51% CdCl2.

[0032] (4) The geopolymer material block was finely ground until the mass fraction of -45µm was 72.34% and the specific surface area was 456m². 2 / kg of amorphous geopolymer material, which is an amorphous material composed of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra, with an amorphous glass content of 92%. A cementitious material is prepared by mixing 80% of the amorphous geopolymer material with 20% cement. The compressive strength after 28 days is 82 MPa, and the flexural strength is 7.1 MPa. The flowchart is as follows. Figure 1 As shown.

[0033] Depend on Figure 2 It can be seen that, since the XRD content of Ni, Cr, and Cu is less than 5%, they are not shown in the XRD, and the main phase of the obtained ferroalloy is metallic iron. Figure 3 It can be seen that the XRD pattern of the obtained geopolymer material block mainly shows amorphous diffraction peaks, indicating that it has an amorphous glass structure. Since the slag phase system of iron tailings and waste incineration fly ash is mainly composed of silicon, aluminum, and oxygen, it indicates that the obtained geopolymer is mainly an amorphous structure composed of silicon and aluminum-oxygen tetrahedra. Figure 4 It can be seen that the secondary fly ash obtained is mainly composed of chlorides such as NaCl, KCl, ZnCl2, PbCl2, and CdCl2.

[0034] The mass percentage of the main elements of the waste incineration fly ash in this embodiment is as follows: Ca 50.25%, C 0.89%, Si 1.83%, Al 2.11%, Cl 14.14%, Fe 1.14, Na 2.21%, K 4.09%, and S 1.56%. The waste incineration fly ash also includes the following mass percentage of heavy metal elements: Zn 0.48%, Pb 0.12%, Cu 0.08%, Ni 0.02%, Cr 0.12%, and Cd 0.01%.

[0035] The main chemical composition percentage of the iron tailings is as follows: Fe2O3 12.15%, SiO2 48.50%, Al2O3 16.43%, CaO 8.92%, and MgO 5.44%.

[0036] Embodiment 2

[0037] A method for utilizing waste incineration fly ash and iron tailings, comprising the following steps:

[0038] The iron tailings are ball milled in a ball mill at a grinding concentration of 55% for 5 min, and finely ground to 83% of -150 μm. 50% of the waste incineration fly ash is mixed with 50% of the iron tailings, and then placed in a smelting furnace to be smelted and reduced at 1300°C for 30 min. During the smelting process, the system becomes a liquid phase. Due to the density difference between the iron alloy and the slag liquid, the iron alloy with a large density will gather at the bottom. The iron alloy liquid flows out from the tapping hole at the bottom of the smelting furnace, and the slag liquid flows out from the slag tapping hole. As shown in FIG. 1, the iron alloy and the geopolymer material block are obtained by natural cooling; through testing, the iron grade of the iron alloy is 97.31%, the iron recovery rate is 91.48%, and it contains trace amounts of Ni, Cu, Cr, and other iron-loving metals. Figure 5

[0039] 4.85%, ZnCl2 4.31%, and CdCl2 1.08%. The geopolymer material block is finely ground, and the mass fraction of -45 µm is 89.34%, the specific surface area is 585 m 2 ​ / kg of amorphous geopolymer material, which is an amorphous material composed of silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron, wherein the amorphous vitreous content is 98%. The cementitious material is prepared by mixing 90% of the amorphous geopolymer material with 10% of cement, and the compressive strength is 86 MPa and the flexural strength is 8.9 MPa at 28 days. In this embodiment, the mass percentage of the main elements of the waste incineration fly ash is: Ca 43.52%, C 17.92%, Si 3.77%, Al 2.24%, Cl 16.78%, Fe 1.23%, Na 2.21%, K 2.58%, and S 0.96%. The waste incineration fly ash also includes the following mass percentage of heavy metal elements: Zn 0.35%, Pb 0.28%, Cu 0.07%, Ni 0.02%, Cr 0.08%, and Cd 0.05%.

[0040] The mass percentage of the main chemical components of the iron tailings is: Fe2O322.31%, SiO227.45%, Al2O323.43%, CaO 16.23%, and MgO 1.78%.

[0041] Example 3

[0042] A method for utilizing waste incineration fly ash and iron tailings, comprising the following steps:

[0043] The iron tailings are ball milled in a ball mill at a grinding concentration of 70% for 25 min, and finely ground to 96% of -150 μm. 75% of the waste incineration fly ash, 20% of the iron tailings, and 5% of sodium carbonate are uniformly mixed and then placed in a smelting furnace, and calcined and reduced at 1200℃ for 60 min. During the smelting process, the system becomes a liquid phase, the iron liquid flows out from the iron port, and the slag liquid flows out from the slag port, and is naturally cooled to obtain an iron alloy and a geopolymer material block. The assay shows that the iron grade of the iron alloy is 96.56%, the iron recovery rate is 90.95%, and it also contains trace amounts of Ni, Cu, Cr, and other iron-loving metals. During the smelting and reducing process, the secondary fly ash is captured by a flue gas capture system to obtain a mixture of NaCl 54.59%, KCl 30.88%, PbCl2 5.23%, ZnCl2 4.35%, and CdCl2 1.81%. The geopolymer material block is finely ground, and the mass fraction of -45 μm is 93.07%, the specific surface area is 511 m 2 / kg of amorphous polymer material, the amorphous polymer material is an amorphous material composed of silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron and a small amount of phosphorus-oxygen tetrahedron, wherein the amorphous glass content is 95%. The cementitious material prepared by mixing 85% of the amorphous polymer material with 15% of cement has a 28-day compressive strength of 78 MPa and a flexural strength of 7.3 MPa. In this embodiment, the mass percentage of the main elements of the waste incineration fly ash is: Ca 19.85%, C 6.89%, Si 9.58%, Al 7.56%, Cl 28.59%, Fe 8.58%, Na 4.08%, K 1.59%, S 1.20%, and the waste incineration fly ash further includes the following mass percentage of heavy metal elements: Zn 0.41%, Pb 0.32%, Cu 0.05%, Ni 0.01%, Cr 0.05%, and Cd 0.06%.

[0044] The mass percentage of the main chemical components of the iron tailings is: Fe2O3 8.72%, SiO2 64.56%, Al2O3 11.89%, CaO 2.92%, and MgO 2.44%.

[0045] The present application uses waste incineration fly ash and iron tailings as raw materials, and adds additives if necessary, to obtain three products of ferroalloy, geopolymer material and secondary fly ash through low-energy consumption high-temperature smelting reduction. The waste incineration fly ash in the present application can provide the reducing agent carbon required for high-temperature smelting reduction reaction, compared with direct reduction process and other processes, the use of relatively high-cost coke and coal powder is avoided, the processing cost is reduced, and the pollution to the environment in the coking process is reduced. At the same time, the heavy metal oxides (such as Cu, Ni, Cr, etc.) in the waste incineration fly ash, the iron oxides in the magnetite and augite in the iron tailings are reduced to metallic iron and other metals under high-temperature reducing atmosphere, realizing the reduction of metal oxides in the system and the directional recovery of heavy metals. In addition, volatile metals and chlorine in fly ash form chlorides at high temperature, obtaining geopolymer material with wide application value, realizing the reduction and harmless of waste incineration fly ash, and the full resource utilization of waste incineration fly ash and resource utilization and iron tailings, providing a new path for the resource utilization of waste incineration fly ash and iron tailings.

[0046] Due to the synergistic effect of the co-melting reduction of the waste incineration fly ash and the iron tailings, the melting point of the system is lower, the melting temperature is lower than 1300 DEG C, and the energy consumption is saved; meanwhile, the high content of SiO2 in the iron tailings can obviously control the viscosity of the fly ash and the iron tailings SiO2-Al2O3-CaO slag phase system, which is beneficial to the aggregation of the iron particles, and the aggregation into the iron alloy liquid flows out through the tapping hole of the smelting furnace. If the reduction is carried out through a muffle furnace, finally, a large spherical particle with a particle size of more than 5mm is formed, and after cooling, it is automatically separated from the oligomer block. The iron grade of the obtained iron alloy is more than 95%, and the iron recovery rate is more than 90%; the obtained geopolymer material is mainly composed of silicon oxygen tetrahedron and aluminum oxygen tetrahedron, and the specific surface area is 456-585m 2 / kg, 70-95% geopolymer material and 5-30% cement are mixed to prepare a cementitious material, and the 28-day compressive strength is 78-86Mpa, and the flexural strength is 7.3-8.9Mpa. The geopolymer material has a wider application and better effect. The secondary fly ash product (mainly including NaCl, KCl, PbCl2, ZnCl2 and CdCl2) is obtained by the smoke gas collection system, and can be used as a raw material for industrial preparation of lead and zinc. Compared with the traditional iron tailings direct reduction process, the process of the present application is simpler and does not need magnetic separation, and the cost is lower. Compared with the direct melting of fly ash, the process has lower energy consumption, and the obtained product has higher utilization value. In summary, the present application provides a new technical route for the resource utilization of fly ash and iron tailings.

[0047] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0048] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for utilizing waste incineration fly ash and iron tailings, characterized by, The method comprises the following steps: The iron alloy, the geopolymer material block and the secondary fly ash are prepared by mixing the waste incineration fly ash and the finely ground iron tailings and then performing a smelting reduction reaction. The smelting reduction reaction comprises the following steps: the waste incineration fly ash and the finely ground iron tailings are mixed and then placed in a smelting furnace to perform a smelting reduction at 1050-1200°C for 30-180 min, then the iron alloy liquid flows out from the tapping hole at the bottom of the smelting furnace, the slag liquid flows out from the slag tapping hole of the smelting furnace, and the molten slag is naturally cooled or water-quenched to obtain the geopolymer material block. The mass percentage of the main components of the iron tailings is as follows: Fe2O3 5-25 %, SiO2 64.56-70 %, Al2O3 5-25 %, CaO 2-20 %, and MgO 2-10 %. The geopolymer material block is finely ground to a mass fraction of ≥70% and a specific surface area of ≥400 m 2 / kg, to obtain an amorphous geopolymer material composed of silicon-oxygen tetrahedron and aluminum-oxygen tetrahedron, wherein the glass substance content is ≥90%; the amorphous geopolymer material with a mass fraction of 70-95% and cement with a mass fraction of 5-30% are mixed, and the compressive strength after 28 days is ≥70 Mpa and the flexural strength is ≥6 Mpa. The mass percentage of the main elements of the waste incineration fly ash is as follows: Ca 10-60 %, C 5-20 %, Si 0.1-10 %, Al 0.1-8 %, Cl 10-30 %, Fe 0.1-8 %, Na 0.1-6 %, K 0.1-6 %, S 0.1-3 %, Zn 0-1 %, Pb 0-1 %, Cr 0-1 %, Cu 0-1 %, Ni 0-1 %, and Cd 0-1 %. Before the smelting reduction reaction, the waste incineration fly ash, the finely ground iron tailings and an additive are mixed, the mass percentage of the additive is 5-10 %, and the additive is sodium carbonate.

2. The method for utilizing waste incineration fly ash and iron tailings according to claim 1, characterized by, The mass percentage of the iron tailings is 20-80 %, and the mass percentage of the waste incineration fly ash is 20-80 %.

3. The method for utilizing waste incineration fly ash and iron tailings according to claim 1, characterized by, The finely ground iron tailings are obtained by the following steps: the iron tailings are ground at a grinding concentration of 55-70 % for 5-25 min, and the grinding is performed to a size of not less than 80 % of-150 μm.

4. The method for utilizing waste incineration fly ash and iron tailings according to claim 1, characterized by, During the smelting reduction reaction, a flue gas collecting device is used to collect the flue gas to obtain the secondary fly ash, and the secondary fly ash is a mixture of NaCl 10-80 %, KCl 10-80 %, PbCl2 1-10 %, ZnCl2 1-10 %, and CdCl2 0-10 %.

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