A method for co-disposing of waste incineration fly ash and cyanide-containing tailings pulp and products thereof

Abstract

The application discloses a method for cooperatively treating waste incineration fly ash and cyanide-containing tailings pulp and a product thereof, and the method comprises the following steps: mixing waste incineration fly ash, smelting solid waste and dredging dry sludge, uniformly stirring, grinding, and obtaining an external mixing mixture; mixing the external mixing mixture and dry cyanide-containing tailings, uniformly stirring, and grinding, and obtaining initial granulation material; mixing an oil separator precipitate and the initial granulation material, adding water, uniformly stirring, static pressure granulating, obtaining granulation material, standing and stacking, calcining, and obtaining calcined material as artificial aggregate. The application realizes granulation, calcination detoxification and resource utilization of waste incineration fly ash and cyanide-containing tailings by reasonably matching the waste incineration fly ash and the cyanide-containing tailings and by matching river dredging sludge, smelting solid waste and oil separator precipitate. The prepared artificial aggregate has the lowest heavy metal leaching toxicity of less than 0.001 mg / L, the lowest chlorine content of less than 0.02%, and the highest cylinder compressive strength of more than 15 MPa.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for co-treatment of waste incineration fly ash and cyanide-containing tailings slurry and a product thereof, and belongs to the field of hazardous waste resource utilization. BACKGROUND

[0002] With the acceleration of industrialization and the improvement of urbanization level, the production of waste incineration fly ash and cyanide-containing tailings slurry is increasing year by year. Waste incineration fly ash contains various heavy metals and organic pollutants, while cyanide-containing tailings slurry has extremely high environmental hazards due to the presence of highly toxic cyanide. Therefore, how to efficiently and safely treat these wastes has become a problem to be solved. Co-treatment as an innovative waste treatment method, which co-treats waste incineration fly ash and cyanide-containing tailings slurry, not only can improve the treatment efficiency, but also can reduce the treatment cost, has important theoretical feasibility and practical significance.

[0003] Waste incineration fly ash is a solid waste produced by high-temperature incineration of waste in waste incineration power plants. These fly ash is mainly composed of non-combustible minerals and incompletely combusted organic matter, and its production accounts for about 3% to 5% of the total amount of waste (furnace grate incineration). Due to the complex composition of waste, fly ash may contain various heavy metals (such as Pb, Cd, Cu, Cr, Zn, etc.) and organic pollutants (such as dioxins, furans, etc.). Heavy metals in waste incineration fly ash are easily leached by water, thereby polluting water bodies and soil. The accumulation of these heavy metals in the environment can have a negative impact on the growth and reproduction of plants and animals, ultimately affecting human health through the food chain.

[0004] Cyanide-containing tailings slurry is mainly derived from tailings, waste slag, sludge and dust slag produced in the process of metal smelting and mining. These wastes contain a large amount of cyanide, which is one of the common toxic and harmful wastes in industrial production. Cyanide is highly toxic to warm-blooded animals and humans, and its characteristics are high toxicity and fast action. Even in low-concentration hydrogen cyanide air, people may have symptoms such as headache, discomfort, and irregular heartbeat; at high concentrations, it may cause immediate death or rapid death. If cyanide-containing tailings slurry is discharged directly without treatment, it will pose a threat to aquatic organisms and human health. In addition, cyanide can also react with other substances in water bodies to produce more harmful substances.

[0005] Waste incineration fly ash and cyanide-containing tailings slurry share certain similarities in waste characteristics, such as the presence of heavy metals and toxic substances. Therefore, similar technical routes and methods can be employed in their treatment. Currently, treatment technologies for waste incineration fly ash and cyanide-containing tailings slurry are relatively mature, including chemical stabilization, solidification / stabilization, and thermal treatment. These technologies can effectively remove harmful substances from the waste and reduce its environmental impact. When co-processing these two types of waste, their respective characteristics can be comprehensively considered to select appropriate treatment technologies, achieving efficient and safe waste disposal. Co-processing can fully utilize the characteristics of both types of waste, maximizing resource utilization. Through co-processing waste incineration fly ash and cyanide-containing tailings slurry, harmful substances can be effectively removed or stabilized, reducing the degree of environmental pollution. This helps protect the ecological environment and human health, achieving sustainable development. Co-processing requires the comprehensive application of multiple technologies and methods, which will drive the progress and innovation of related technologies. By researching and developing new treatment technologies and methods, the efficiency and safety of waste treatment can be improved, providing new ideas and methods for the development of the waste treatment field. Summary of the Invention

[0006] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method and products for the resource-based co-processing of waste incineration fly ash and cyanide-containing tailings slurry.

[0007] Technical Solution: To solve the above-mentioned technical problems, the present invention provides a method for co-processing fly ash from waste incineration and cyanide-containing tailings slurry, comprising the following steps:

[0008] (1) Mix the fly ash from waste incineration, solid waste from metallurgy and dredged dry mud, stir evenly, grind, and obtain the external admixture;

[0009] (2) Mix the external admixture and dry cyanide tailings, stir evenly, grind, and obtain the initial granulated material;

[0010] (3) Mix the oil separator sediment and the initial granulated material, add water, stir evenly, granulate under static pressure to obtain granulated material, let it stand and stack, calcinate, and the obtained calcined material is artificial aggregate.

[0011] In step (1), the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud is 40~120:20~80:100. The heavy metal leaching concentration of the prepared artificial aggregate is less than 0.1 mg / L, the soluble chlorine content of the prepared artificial aggregate is less than 0.15%, and the barrel compressive strength of the prepared artificial aggregate is greater than 8 MPa.

[0012] The smelting solid waste mentioned in step (1) is any one of blast furnace gas mud, blast furnace gas ash or steel slag.

[0013] The water content of the dredged dry sludge in step (1) is less than 5% to 25%.

[0014] The grinding time in step (2) is 0.25 to 2.75 hours.

[0015] The mass ratio of the external admixture and the dry cyanide tailings in step (2) is 40 to 80:100, the heavy metal leaching concentration of the prepared artificial aggregate is less than 0.01 mg / L, the soluble chlorine content of the prepared artificial aggregate is less than 0.05%, and the barrel compression strength of the prepared artificial aggregate is greater than 11 MPa.

[0016] The water content of the dry cyanide tailings in step (2) is less than 5% to 25%.

[0017] The grinding time in step (2) is 0.25 to 2.75 hours.

[0018] The mass ratio of the oil separator precipitate and the initial granulation material in step (3) is 2.5 to 22.5:100, the heavy metal leaching concentration of the prepared artificial aggregate is less than 0.01 mg / L, the soluble chlorine content of the prepared artificial aggregate is less than 0.01%, and the barrel compression strength of the prepared artificial aggregate is greater than 14 MPa.

[0019] The initial water content of the granulation material in step (3) is controlled to be 30% to 50%.

[0020] The standing and stacking time in step (3) is 1 to 3 days.

[0021] The calcination temperature in step (3) is 750 to 1250 DEG C, and the calcination time is 20 to 60 minutes.

[0022] The application further provides an artificial aggregate prepared by the method.

[0023] Reaction mechanism: mixed waste incineration fly ash, smelting solid waste, dredging dry mud, fully contact in the process of stirring and grinding. Mixed with doped materials and dry cyanide tailings, fully contact in the process of stirring and grinding. Mix the oil separator precipitate and the initial granulation material, add appropriate water, stir and static pressure, the inorganic chloride salt in the waste incineration fly ash dissolves into the liquid phase, the calcium-based material reacts with water to generate calcium hydroxide. Calcium hydroxide and dissolved chloride salt promote the alkali dissolution and bond breaking of the oil separator precipitate through weak alkali activation, thereby improving the diffusion of methyl silicic acid and reducing its hydrophobicity, and improving its hydrophilic reactivity. Calcium hydroxide and dissolved chloride salt can also promote the dissolution and polymerization of silicate and aluminate in smelting solid waste, dredging dry mud and cyanide tailings through weak alkali activation, and further react with alkali-dissolved methyl silicic acid diffused into the pores to generate silicate, aluminate, calcium, sodium and potassium-based chlorinated gel. The generated gel adsorbs cyanide and fully wraps other unreacted materials to form granulation material. The granulation is introduced into the kiln for calcination, and the unreacted calcium hydroxide and chloride salt can catalyze and accelerate the decomposition of cyanide during calcination. At the same time, chloride salt is easy to react with iron-based minerals in smelting solid waste to generate iron trichloride gas during calcination, thereby inhibiting the generation of heavy metal chloride gas in waste incineration fly ash and cyanide-containing tailings. Under the penetration of molten chloride salt, the organic silicon in the oil separator precipitate is rapidly carbonized and forms a silicon-based melt. The formed molten chloride salt and carbon-containing silicon-based melt wrap the silicate and aluminate gel and other unreacted materials, promoting the melting and slagging of the gel. The carbonized body in the melt is beneficial to the selective capture and adsorption of heavy metal pollutants and inorganic salts, thereby strengthening the formation of heavy metals and inorganic salts in the melt and glassy solidification.

[0024] Advantages: Compared with the prior art, the present application has the following advantages: the present application matches waste incineration fly ash and cyanide-containing tailings, and matches river dredging sludge, smelting solid waste and oil separator precipitate, realizes the granulation and calcination detoxification of waste incineration fly ash and cyanide-containing tailings, and realizes resource utilization. The heavy metal leaching toxicity of the prepared artificial aggregate is less than 0.001 mg / L, the chlorine content is less than 0.02%, and the aggregate cylinder strength is higher than 15 MPa. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The flowchart of the preparation method of the present application. DETAILED DESCRIPTION

[0026] The technical solutions of the present application will be further described below with reference to the accompanying drawings.

[0027] MSWI fly ash: MSWI fly ash was provided by Jiangsu Changshu Puhua No. 2 Thermal Power Energy Co., Ltd. and mainly included 38.92% CaO, 19.84% Cl, 12.51% SO3, 11.79% Na2O, 5.26% K2O, 3.98% SiO2, 1.40% Fe2O3, 1.25% Al2O3, and other components (loss on ignition and other unavoidable impurities);

[0028] BF gas mud: BF gas mud was provided by Panzhihua New Steel Vanadium Co., Ltd. and mainly included 41.26% TFe, 32.84% C, 8.63% SiO2, 5.23% ZnO, 3.13% CaO, 2.65% Al2O3, 1.59% K2O, and other components (loss on ignition and other unavoidable impurities);

[0029] BF gas ash: BF gas ash was provided by Panzhihua New Steel Vanadium Co., Ltd. and mainly included 43.59% Fe2O3, 15.32% CaO, 6.51% MgO, 4.69% SiO2, 1.87% Al2O3, and other components (loss on ignition and other unavoidable impurities);

[0030] Steel slag: Steel slag was taken from Jiangyin Huaxi Iron and Steel Co., Ltd. and the chemical components of the steel slag included 35.92% CaO, 26.34% Fe2O3, 19.16% SiO2, 7.32% Al2O3, 4.56% MgO, 2.28% MnO, 1.17% P2O5, 0.84% TiO2, 0.62% SO3, and other (unavoidable loss on ignition);

[0031] Oil separator precipitate: Oil separator precipitate was provided by Sinopec Group Petroleum Chemical Co., Ltd.

[0032] Example 1 Influence of mass ratio of MSWI fly ash, smelting solid waste, and dredged dry mud on strength and leaching toxicity of prepared artificial aggregate

[0033] The river dredging sludge is dried to have a water content of less than 5%, to obtain the dried dredging sludge. The cyanide-containing tailings slurry is dried to have a water content of less than 5%, to obtain the dried cyanide-containing tailings. The waste incineration fly ash, the smelting solid waste and the dried dredging sludge are weighed according to the mass ratio of 25:20:100, 30:20:100, 35:20:100, 40:12.5:100, 40:15:100, 40:17.5:100, 40:20:100, 80:20:100, 120:20:100, 40:50:100, 80:50:100, 120:50:100, 40:80:100, 80:80:100, 120:80:100, 120:90:100, 120:100:100, 120:110:100, 130:80:100, 140:80:100, 150:80:100, respectively, mixed, uniformly stirred, and ground for 0.25 hours, to obtain the external admixture, wherein the smelting solid waste is the blast furnace gas sludge. The external admixture and the dried cyanide-containing tailings are weighed according to the mass ratio of 40:100, mixed, uniformly stirred, and ground for 0.25 hours, to obtain the initial granulation material. The oil separator precipitate and the initial granulation material are mixed according to the mass ratio of 2.5:100, uniformly stirred, and pressure granulated, to obtain the granulation material, wherein the initial water content of the granulation material is controlled to be 30%. The granulation material is placed and stacked for 1 day, and then introduced into a kiln for calcination, to obtain the calcined material, which is the artificial aggregate, wherein the calcination temperature is 750°C, and the calcination time is 20 minutes.

[0034] Bucket compression strength test: The bucket compression strength of the artificial aggregate is determined according to the “Lightweight Aggregate and Test Methods for Lightweight Aggregate Part 1: Lightweight Aggregate” (GB-T17431.1-2010).

[0035] Preparation of leaching solution: The leaching solution of the artificial aggregate is prepared according to the “Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method” (HJ 557-2010).

[0036] Determination of heavy metal ion concentration in leaching solution: The concentrations of lead and cadmium in the leaching solution are determined according to the “Determination of 32 Elements in Water by Inductively Coupled Plasma Atomic Emission Spectrometry” (HJ 776-2015). The total chromium in the leaching solution is determined according to the “Determination of Chromium in Water by Flame Atomic Absorption Spectrophotometry” (HJ 757-2015).

[0037] Determination of chlorine content: The chlorine content in the artificial aggregate is determined according to the “Construction Sand” (GB / T 14684-2011). The results are shown in Table 1.

[0038] Table 1 Influence of mass ratio of waste incineration fly ash, smelting solid waste and dredging dry sludge on strength and leaching toxicity of the prepared artificial aggregate

[0039]

[0040] As can be seen from Table 1, when the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud is less than 40:20:100 (for example, the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud = 35:20:100, 30:20:100, 25:20:100, 40:17.5:100, 40:15:100, 40:12.5:100 and lower ratios not listed in Table 1), the addition of waste incineration fly ash and smelting solid waste is less, and the subsequent reaction is unbalanced, resulting in that the heavy metal leaching concentration and the chlorine content of the prepared artificial aggregate are significantly increased with the decrease of the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud, and the barrel pressure strength of the prepared artificial aggregate is significantly reduced with the decrease of the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud. When the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud is equal to 40-120:20-80:100 (for example, the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud = 40:20:100, 80:20:100, 120:20:100, 40:50:100, 80:50:100, 120:50:100, 40:80:100, 80:80:100, 120:80:100), the mixed waste incineration fly ash, smelting solid waste and dredged dry mud are fully contacted in the stirring and grinding process, and the materials are fully reacted in the subsequent compounding and calcination process. Finally, the heavy metal leaching concentration of the prepared artificial aggregate is less than 0.1 mg / L, the soluble chlorine content of the prepared artificial aggregate is less than 0.15%, and the barrel pressure strength of the prepared artificial aggregate is greater than 8 MPa. When the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud is greater than 120:80:100 (for example, the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud = 120:90:100, 120:100:100, 120:110:100, 130:80:100, 140:80:100, 150:80:100 and higher ratios not listed in Table 1), the addition of waste incineration fly ash and smelting solid waste is excessive, and the material matching is unbalanced, resulting in that the heavy metal leaching concentration and the chlorine content of the prepared artificial aggregate are significantly increased with the further increase of the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud, and the barrel pressure strength of the prepared artificial aggregate is significantly reduced with the further increase of the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud. Therefore, in general, when the mass ratio of waste incineration fly ash, smelting solid waste and dredged dry mud is equal to 40-120:20-80:100, it is most beneficial to the preparation of artificial aggregate.

[0041] Example 2 Influence of the mass ratio of external mixing material and dry cyanide tailings on the strength and leaching toxicity of the prepared artificial aggregate

[0042] The river dredging sludge is dried to have a water content of less than 15%, to obtain the dried dredging sludge. The cyanide-containing tailings slurry is dried to have a water content of less than 15%, to obtain the dried cyanide-containing tailings. The refuse incineration fly ash, the smelting solid waste and the dried dredging sludge are weighed according to the mass ratio of 120:80:100, mixed, stirred uniformly, and ground for 1.5 hours, to obtain the mixed material, wherein the smelting solid waste is blast furnace gas ash. The mixed material and the dried cyanide-containing tailings are weighed according to the mass ratios of 25:100, 30:100, 35:100, 40:100, 60:100, 80:100, 85:100, 90:100 and 95:100, respectively, mixed, stirred uniformly, and ground for 1.5 hours, to obtain the initial granulation material. The oil separator precipitate and the initial granulation material are mixed according to the mass ratio of 12.5:100, and appropriate water is added, stirred uniformly, and pressure granulated, to obtain the granulation material, wherein the initial water content of the granulation material is controlled to be 40%. The granulation material is placed and stacked for 2 days, and then introduced into a kiln for calcination, to obtain the calcined material, which is artificial aggregate, wherein the calcination temperature is 1000℃, and the calcination time is 40 minutes.

[0043] The barrel compression strength test, the leaching liquid preparation, the heavy metal ion concentration determination in the leaching liquid and the chlorine content determination are the same as those in Example 1, and the results of this example are shown in Table 2.

[0044] Table 2 Influence of mass ratio of mixed material and dried cyanide-containing tailings on strength and leaching toxicity of prepared artificial aggregate

[0045]

[0046] As shown in Table 2, when the mass ratio of the admixture and the dry cyanide tailings is less than 40: 100 (e.g., the mass ratio of the admixture and the dry cyanide tailings = 35: 100, 30: 100, 25: 100, and lower ratios not listed in Table 2), the admixture is added in a small amount, and the subsequent reaction is unbalanced, resulting in the heavy metal leaching concentration and the chlorine content of the prepared artificial aggregate significantly increasing as the mass ratio of the admixture and the dry cyanide tailings decreases, and the barrel compression strength of the prepared artificial aggregate significantly decreasing as the mass ratio of the admixture and the dry cyanide tailings decreases. When the mass ratio of the admixture and the dry cyanide tailings is equal to 40-80: 100 (e.g., the mass ratio of the admixture and the dry cyanide tailings = 40: 100, 60: 100, 80: 100), the admixture and the dry cyanide tailings are mixed, and the materials are fully contacted during the stirring and grinding process, and the materials fully react during the subsequent mixing and calcination process. Finally, the heavy metal leaching concentration of the prepared artificial aggregate is less than 0.01 mg / L. The soluble chlorine content of the prepared artificial aggregate is less than 0.05%. The barrel compression strength of the prepared artificial aggregate is greater than 11 MPa. When the mass ratio of the admixture and the dry cyanide tailings is greater than 80: 100 (e.g., the mass ratio of the admixture and the dry cyanide tailings = 85: 100, 90: 100, 95: 100, and higher ratios not listed in Table 2), the admixture is added in an excessive amount, and the materials are unbalanced, resulting in the heavy metal leaching concentration and the chlorine content of the prepared artificial aggregate significantly increasing as the mass ratio of the admixture and the dry cyanide tailings further increases, and the barrel compression strength of the prepared artificial aggregate significantly decreasing as the mass ratio of the admixture and the dry cyanide tailings further increases. Therefore, in general, when the mass ratio of the admixture and the dry cyanide tailings is equal to 40-80: 100, it is most beneficial for the preparation of the artificial aggregate.

[0047] Example 3 Effect of the mass ratio of the oil separator precipitate and the initial granulation material on the strength and leaching toxicity of the prepared artificial aggregate

[0048] The river dredging sludge is dried to have a water content of less than 25%, to obtain the dried dredging sludge. The cyanide-containing tailing slurry is dried to have a water content of less than 25%, to obtain the dried cyanide-containing tailing. The refuse incineration fly ash, the smelting solid waste and the dried dredging sludge are weighed according to the mass ratio of 120:80:100, mixed, stirred uniformly, and ground for 2.75 hours, to obtain the mixed material, wherein the smelting solid waste is steel slag. The mixed material and the dried cyanide-containing tailing are weighed according to the mass ratio of 80:100, mixed, stirred uniformly, and ground for 2.75 hours, to obtain the initial granulation material. The separator precipitate and the initial granulation material are mixed according to the mass ratio of 1:100, 1.5:100, 2:100, 2.5:100, 12.5:100, 22.5:100, 25:100, 27.5:100 and 30:100, added with appropriate water, stirred uniformly, and pressure granulated, to obtain the granulation material, wherein the initial water content of the granulation material is controlled to be 50%. The granulation material is placed for 3 days, and then introduced into a kiln for calcination, to obtain the calcined material, which is artificial aggregate, wherein the calcination temperature is 1250℃, and the calcination time is 60 minutes.

[0049] The barrel compression strength test, the leaching liquid preparation, the heavy metal ion concentration determination in the leaching liquid and the chlorine content determination are the same as those in Example 1, and the results of this example are shown in Table 3.

[0050] Table 3: Effect of the mass ratio of separator precipitate and initial granulation material on the strength and leaching toxicity of the prepared artificial aggregate

[0051]

[0052] As shown in Table 3, when the mass ratio of the oil separator precipitate and the initial granulating material is less than 2.5:100 (e.g., the mass ratio of the oil separator precipitate and the initial granulating material = 2:100, 1.5:100, 1:100, and lower ratios not listed in Table 3), the oil separator precipitate is added less, the subsequent reaction is unbalanced, and the heavy metal leaching concentration and the chlorine content of the prepared artificial aggregate are significantly increased as the mass ratio of the oil separator precipitate and the initial granulating material decreases, while the barrel pressure strength of the prepared artificial aggregate is significantly reduced as the mass ratio of the oil separator precipitate and the initial granulating material decreases. When the mass ratio of the oil separator precipitate and the initial granulating material is equal to 2.5-22.5:100 (e.g., the mass ratio of the oil separator precipitate and the initial granulating material = 2.5:100, 12.5:100, 22.5:100), the inorganic chloride salt in the waste incineration fly ash is dissolved into the liquid phase during the mixing of the oil separator precipitate and the initial granulating material, the addition of appropriate water, stirring, and static pressure process, and calcium-based materials react with water to generate calcium hydroxide. The calcium hydroxide and the dissolved chloride salt promote the alkali dissolution and the bond breaking and depolymerization of the oil separator precipitate through weak alkali activation, thereby improving the diffusion of methyl silicic acid and reducing its hydrophobicity, and improving its hydrophilic reactivity. The calcium hydroxide and the dissolved chloride salt also promote the dissolution and polymerization of silico-aluminates in smelting solid waste, dredged dry sludge, and cyanide tailings through weak alkali activation, and further react with the alkali-dissolved methyl silicic acid diffused into the pores to generate silico-aluminic calcium-sodium-potassium-based chlorinated gel. The generated gel adsorbs cyanide and fully wraps heavy metal pollutants and other unreacted materials, forming granulating material. The granulating material is introduced into a kiln for calcination, and unreacted calcium hydroxide and chloride salt can catalyze and accelerate the decomposition of cyanide during the calcination process. At the same time, chloride salt is easy to react with iron-based minerals in smelting solid waste during calcination to generate iron trichloride gas, thereby inhibiting the generation of heavy metal chlorinated gas in waste incineration fly ash and cyanide-containing tailings. Under the penetration of molten chloride salt, organic silicon in the oil separator precipitate is rapidly carbonized and forms a silicon-based melt. The formed molten chloride salt and carbon-containing silicon-based melt wrap the silico-aluminate gel and other unreacted materials, promoting the melting and slagging thereof. The carbonized body in the melt is beneficial to the selective capture and adsorption of heavy metal pollutants and inorganic salts, thereby strengthening the multiphase mineral generation and vitrification solidification of heavy metals and inorganic salts in the melt. Finally, the heavy metal leaching concentration of the prepared artificial aggregate is less than 0.01 mg / L. The soluble chlorine content of the prepared artificial aggregate is less than 0.01%. The barrel pressure strength of the prepared artificial aggregate is greater than 14 MPa.When the mass ratio of decanter sludge and initial granulation material is greater than 22.5:100 (such as the mass ratio of decanter sludge and initial granulation material = 25:100, 27.5:100, 30:100 in Table 3 and higher ratios not listed in Table 3), the decanter sludge is added in excess, the material matching is unbalanced, and the heavy metal leaching concentration and chlorine content of the prepared artificial aggregate are significantly increased with the further increase of the mass ratio of decanter sludge and initial granulation material, while the barrel pressure strength of the prepared artificial aggregate is significantly reduced with the further increase of the mass ratio of decanter sludge and initial granulation material. Therefore, in general, when the mass ratio of decanter sludge and initial granulation material is equal to 2.5-22.5:100, it is most beneficial to the preparation of artificial aggregate.

[0053] Influence of different process types on the strength and leaching toxicity of the prepared artificial aggregate

[0054] The process of the present application: The river channel dredged sludge is dried to have a water content of less than 25%, to obtain dried dredged sludge. The cyanide-containing tailings slurry is dried to have a water content of less than 25%, to obtain dried cyanide-containing tailings. The waste incineration fly ash and smelting solid waste are weighed according to a mass ratio of 120:80:100, respectively, mixed, uniformly stirred, and ground for 2.75 hours to obtain an external mixing material, wherein the smelting solid waste is steel slag. The external mixing material and the dried cyanide-containing tailings are weighed according to a mass ratio of 80:100, respectively, mixed, uniformly stirred, and ground for 2.75 hours to obtain an initial granulation material. The decanter sludge and the initial granulation material are mixed according to a mass ratio of 22.5:100, and appropriate water is added, uniformly stirred, and statically granulated to obtain a granulation material, wherein the initial water content of the granulation material is controlled to be 50%. The granulation material is placed and stacked for 3 days, and then introduced into a kiln for calcination to obtain a calcined material, which is an artificial aggregate, wherein the calcination temperature is 1250°C and the calcination time is 60 minutes.

[0055] The process of the present application: The river channel dredged sludge is dried to have a water content of less than 25%, to obtain dried dredged sludge. The cyanide-containing tailings slurry is dried to have a water content of less than 25%, to obtain dried cyanide-containing tailings. The waste incineration fly ash and smelting solid waste are weighed according to a mass ratio of 120:80:100, respectively, mixed, uniformly stirred, and ground for 2.75 hours to obtain an external mixing material, wherein the smelting solid waste is steel slag. The external mixing material and the dried cyanide-containing tailings are weighed according to a mass ratio of 80:100, respectively, mixed, uniformly stirred, and ground for 2.75 hours to obtain an initial granulation material. The decanter sludge and the initial granulation material are mixed according to a mass ratio of 22.5:100, and appropriate water is added, uniformly stirred, and statically granulated to obtain a granulation material, wherein the initial water content of the granulation material is controlled to be 50%. The granulation material is placed and stacked for 3 days, and then introduced into a kiln for calcination to obtain a calcined material, which is an artificial aggregate, wherein the calcination temperature is 1250°C and the calcination time is 60 minutes.

[0056] Comparative Process 2: River dredging sludge is dried to have a water content less than 25%, to obtain dried dredging sludge. Cyanide tailings slurry is dried to have a water content less than 25%, to obtain dried cyanide tailings. Garbage incineration fly ash, smelting solid waste and dried dredging sludge are weighed according to the mass ratio of 120:80:100, mixed, stirred uniformly, and ground for 2.75 hours to obtain an external mixing material, wherein the smelting solid waste is steel slag. The external mixing material and the dried cyanide tailings are weighed according to the mass ratio of 80:100, mixed, stirred uniformly, and ground for 2.75 hours to obtain an initial granulation material. Appropriate water is added to the initial granulation material, stirred uniformly, and pressure granulated to obtain a granulation material, wherein the initial water content of the granulation material is controlled to be 50%. The granulation material is placed for 3 days, and then introduced into a kiln for calcination to obtain a calcined material, wherein the calcination temperature is 1250 DEG C, and the calcination time is 60 minutes.

[0057] The barrel compression strength test, the leaching liquid preparation, the heavy metal ion concentration determination in the leaching liquid, and the chlorine content determination are the same as those in Example 1, and the results of the present example are shown in Table 4.

[0058] Table 4 Influence of different process types on the strength and leaching toxicity of the prepared artificial aggregate

[0059]

[0060] As shown in Table 4, the strength of the artificial aggregate prepared by the process of the present application is much higher than that of the aggregate prepared by Comparative Process 1 and Comparative Process 2, and the leaching toxicity of the artificial aggregate prepared by the process is significantly lower than that of the aggregate prepared by Comparative Process 1 and Comparative Process 2.

Claims

1. A method for co-processing fly ash from waste incineration and cyanide-containing tailings slurry, characterized in that, Includes the following steps: (1) Mix the fly ash from waste incineration, solid waste from metallurgy and dredged sludge in a mass ratio of 40~120:20~80:100, stir evenly, grind, and obtain the external admixture; (2) Mix the external admixture and dry cyanide tailings at a mass ratio of 40~80:100, stir evenly, grind, and obtain the initial granulated material; (3) Mix the petrochemical separator sediment and initial granulation material in a mass ratio of 2.5~22.5:100, add water, stir evenly, granulate under static pressure to obtain granulation material, let stand and stack, calcine, and the obtained calcined material is artificial aggregate.

2. The method according to claim 1, characterized in that, The smelting solid waste mentioned in step (1) is any one of blast furnace gas mud, blast furnace gas ash or steel slag.

3. The method according to claim 1, characterized in that, The moisture content of the dredged sludge described in step (1) is less than 25%.

4. The method according to claim 1, characterized in that, The moisture content of the dried cyanide tailings described in step (2) is less than 25%.

5. The method according to claim 1, characterized in that, The grinding time in steps (1) and (2) is 0.25 to 2.75 hours.

6. The method according to claim 1, characterized in that, The initial moisture content of the granulated material in step (3) is controlled at 30%~50%.

7. The method according to claim 1, characterized in that, The static stacking time mentioned in step (3) is 1 to 3 days.

8. The method according to claim 1, characterized in that, The calcination temperature in step (3) is 750~1250℃, and the calcination time is 20~60 minutes.

9. An artificial aggregate prepared by the method according to any one of claims 1 to 8.

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