A method for synchronous harmless resource utilization of waste lead paste and waste incineration fly ash

Abstract

The application discloses a method for synchronously harmless and resourceful treatment of waste lead paste and waste incineration fly ash. The method comprises the following steps: mixing raw materials including waste lead paste, waste incineration fly ash and solid fuel to form a lump, drying and roasting the lump in sequence, and recovering a lead-containing component from flue gas and particulate matters, wherein the main component of the remaining solid residue is CaSO4. Through the high-temperature roasting process, the method realizes degradation of dioxin pollutants in the waste incineration fly ash, and realizes resourceful utilization of all components of the waste lead paste and the waste incineration fly ash.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for synchronous harmless resource utilization of waste lead paste and waste incineration fly ash, in particular to a method for recovering lead-containing components and obtaining calcium sulfate products by high-temperature roasting of waste lead paste and waste incineration fly ash, belonging to the field of hazardous waste co-harmless and resource utilization. BACKGROUND

[0002] Lead-acid batteries are widely used in transportation, communication, power and other fields due to their low cost, stable voltage and large capacity. With the increasing market demand for lead-acid batteries and the continuous depletion of lead ore resources, recycling lead resources from waste lead paste is of great significance to ensure lead supply. In addition, efficient resource utilization of waste lead paste helps to reduce the serious threat to the ecological environment and human health.

[0003] At present, the resource utilization of waste lead paste mainly includes pyrometallurgical and hydrometallurgical processes. Compared with the hydrometallurgical process, the pyrometallurgical process has the advantages of short process, large treatment capacity and low investment. However, the existing direct reduction process has high energy consumption and large loss of lead and its compounds during the treatment process. SUMMARY

[0004] In view of the problems of large amount of waste lead paste and waste incineration fly ash, high content of toxic components and difficult resource utilization in the prior art, the present application aims to provide a method for synchronous harmless resource utilization of waste lead paste and waste incineration fly ash. This method makes full use of the composition characteristics of waste lead paste rich in lead compounds and waste incineration fly ash rich in chlorine. By high-temperature roasting of waste lead paste and waste incineration fly ash, lead can be converted into low-boiling-point lead-containing components such as PbO and PbCl2, which can be recovered from flue gas and particulate matter. The main component of the solid residue is CaSO4, which can be used as a building material. At the same time, the high-temperature roasting process realizes the degradation of dioxin pollutants in waste incineration fly ash, achieving synchronous harmless and full-component resource utilization of waste lead paste and waste incineration fly ash. This method has important significance for resource recycling and ecological environment protection.

[0005] In order to achieve the above technical purpose, the present application provides a method for synchronous harmless resource utilization of waste lead paste and waste incineration fly ash. The method is to mix and form a lump of raw materials including waste lead paste, waste incineration fly ash and solid fuel. The obtained lump is sequentially dried and roasted, and lead-containing components are recovered from the roasting flue gas and particulate matter. The main component of the remaining solid residue is CaSO4.

[0006] The key technical solution of the present application is to utilize waste lead paste and waste incineration fly ash for collaborative treatment, utilize the chloride salt components in the waste incineration fly ash to chlorinate and volatilize the lead components in the waste lead paste, so that the PbSO4, PbO2, PbO, Pb and other lead components in the waste lead paste are subjected to chlorination reaction to generate low-boiling-point lead chloride and efficiently volatilize into flue gas, and the lead-containing components are captured in a flue gas purification unit, so that high-grade lead-containing components can be obtained, and the decomposition of dioxins in the waste incineration fly ash is realized by using a high-temperature process, and the main component of the solid-phase residue after roasting is CaSO4, which can be used for building materials, so that the waste lead paste and the waste incineration fly ash are simultaneously harmless and fully component resourceized.

[0007] As a preferred solution, the molar ratio of chlorine to lead in the waste lead paste and the waste incineration fly ash mixture satisfies: n(Cl) / 2n(Pb) is 0.8-1.1; and further preferably, the molar ratio satisfies: n(Cl) / 2n(Pb) is 0.9-1.1. If the chlorine content in the material is too low, the lead-containing components will be left, and the recovery rate will be reduced. When the chlorine content in the material is too high, the chlorine-containing components are easy to generate HCl at high temperature, and the equipment corrosion is intensified.

[0008] As a preferred solution, the mass of the solid fuel accounts for 5-15% of the total mass of the raw materials; and the solid fuel includes coke, coal powder, anthracite and the like, and the mass is measured according to the fixed carbon content. The solid fuel combustion provides heat for the reaction, and creates a local unreduced atmosphere, which promotes the synchronous resourceization process.

[0009] As a preferred solution, the raw materials further include a binder with a mass percentage of ≤5%, such as bentonite, starch, humic acid and the like.

[0010] As a preferred solution, the drying temperature is 80-150℃, and the time is 30-180min.

[0011] As a preferred solution, the roasting temperature is 900-1350℃, and the time is 10-60min. If the roasting temperature is too low, the reaction rate of the system will be slow, and the reaction degree will be low; if the temperature is too high, the solid-state material will be melted, and then adhered to the furnace lining, which affects the smooth running and service life of the equipment, and the high temperature will increase the energy consumption of the treatment process. Further preferably, the temperature is 1000-1350℃.

[0012] The mixing methods involved in the present application include stirring mixing, spiral mixing, mechanical gripper mixing and the like.

[0013] The balling methods involved in the present application include disc balling, cylinder balling, briquetting, extrusion forming and the like.

[0014] The application relates to a recycling method of PbO, PbCl2 and other lead-containing components in flue gas and particulate matters, which comprises bag dust collection, cyclone dust removal, electric dust removal, washing type dust removal and the like.

[0015] Compared with the prior art, the application has the following advantages and beneficial technical effects:

[0016] 1) The application realizes harmless treatment and resource utilization of all components of the waste lead paste and the waste incineration fly ash by scientific compounding and high-temperature metallurgical principle. The waste lead paste and the waste incineration fly ash are cooperatively treated by high-temperature roasting, the lead components in the waste lead paste are chlorinated and volatilized by using the chloride salt components in the waste incineration fly ash, the PbSO4, PbO2, PbO and Pb in the waste lead paste are chlorinated to generate low-boiling-point lead chlorides which are efficiently volatilized into flue gas, the lead-containing components are captured in a flue gas purification unit, high-grade lead-containing components are obtained, dioxins in the waste incineration fly ash are decomposed by using the high-temperature process, and the main component of the solid-phase residue after roasting is CaSO4 which can be used for building materials. The method realizes harmless treatment and resource utilization of all components of the waste lead paste and the waste incineration fly ash.

[0017] 2) The application has the characteristics of short treatment process, high efficiency, strong operability, easy large-scale promotion and the like, and has important significance for resource recycling and ecological environment protection. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A process flow diagram for synchronous harmless resource utilization of the waste lead paste and the waste incineration fly ash. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the application, the following will combine the preferred embodiments to describe the application more comprehensively and in detail, but the protection scope of the application is not limited to the following specific embodiments.

[0020] Unless otherwise defined, all the professional terms used in the following have the same meaning as that understood by the person skilled in the art. The professional terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the protection scope of the application.

[0021] Unless otherwise specified, all the reagents and raw materials used in the application can be commercially available products or can be prepared by the known method.

[0022] The waste lead paste mainly comprises PbSO4 and PbO2, and contains a certain amount of PbO and a small amount of elemental Pb. The waste incineration fly ash comprises solid wastes collected from a flue gas purification / dust removal system in a waste incineration power generation process, and mainly comprises CaO, SiO2, Al2O3, NaCl, KCl and the like. The specific components are shown in Tables 1 and 2.

[0023] Table 1 Main phase composition of waste lead paste (%)

[0024] PbSO4 PbO2 PbO Pb Spent lead paste 50.4 25.3 7.2 1.2

[0025] Table 2 Main chemical composition of waste incineration fly ash (%)

[0026] SiO2 Al2O3 CaO Cl Municipal solid waste incineration fly ash 10.5 4.3 37.3 16.25

[0027] Comparative Example 1

[0028] The difference from Example 1 is that n(Cl) / 2n(Pb) = 0.6.

[0029] The removal rate of Pb in the mixture is 42.33%, which indicates that the low proportion of chlorine obviously affects the removal rate of lead.

[0030] Comparative Example 2

[0031] The difference from Example 1 is that the mixture is calcined at 800°C for 45 min.

[0032] The removal rate of Pb in the mixture is 54.2%, which indicates that the low calcination temperature obviously affects the removal rate of lead.

[0033] Example 1

[0034] The waste lead paste, waste incineration fly ash, anthracite and bentonite are mixed according to n(Cl) / 2n(Pb) = 0.95, the anthracite is added by 8%, and the bentonite is added by 3%, and then uniformly mixed. The mixture is prepared into a briquette with a particle size of 10-12 mm by mechanical briquetting, and then dried at 150°C for 60 min. After drying, the briquette is calcined at 1050°C for 45 min. The removal rate of Pb in the mixture is 91.27%, the flue gas dioxin concentration is less than the national standard GB18484-2001, and is less than 0.5 ng TEQ / Nm 3 .

[0035] Example 2

[0036] The waste lead paste is mixed with waste incineration fly ash, coke, and starch according to (n(Cl) / 2n(Pb))=0.8, the coke addition amount is 7%, and the starch addition amount is 2%. The mixture is uniformly mixed and prepared into pellets with a particle size of 10-12 mm by using a disc pelletizer. The pellets are dried at 75°C for 120 min, and then roasted at 900°C for 60 min. The removal rate of Pb in the mixture is 84.21%, and the dioxin concentration in the flue gas is less than 0.5 ng TEQ / Nm 3 .

[0037] Example 3

[0038] The waste lead paste is mixed with waste incineration fly ash, coke, and mineral powder binder according to (n(Cl) / 2n(Pb))=0.9, the coke addition amount is 10%, and the mineral powder binder addition amount is 0%. The mixture is uniformly mixed and prepared into pellets with a particle size of 10-12 mm by using a disc pelletizer. The pellets are dried at 75°C for 120 min, and then roasted at 900°C for 60 min. The removal rate of Pb in the mixture is 84.21%, and the dioxin concentration in the flue gas is less than 0.5 ng TEQ / Nm 3 .

[0039] Example 4

[0040] The waste lead paste is mixed with waste incineration fly ash, coal powder, and bentonite according to (n(Cl) / 2n(Pb))=1.1, the coal powder addition amount is 15%, and the bentonite addition amount is 5%. The mixture is uniformly mixed and prepared into pellets with a particle size of 10-12 mm by using a disc pelletizer. The pellets are dried at 75°C for 120 min, and then roasted at 900°C for 60 min. The removal rate of Pb in the mixture is 84.21%, and the dioxin concentration in the flue gas is less than 0.5 ng TEQ / Nm 3 .

[0041] Example 5

[0042] The waste lead paste is mixed with waste incineration fly ash, coke, and humic acid binder according to (n(Cl) / 2n(Pb))=0.9, the coke addition amount is 5%, and the humic acid binder addition amount is 3%. The mixture is uniformly mixed and prepared into pellets with a particle size of 10-12 mm by using a disc pelletizer. The pellets are dried at 75°C for 120 min, and then roasted at 900°C for 60 min. The removal rate of Pb in the mixture is 84.21%, and the dioxin concentration in the flue gas is less than 0.5 ng TEQ / Nm 3 .

Claims

1. A method for the simultaneous harmless and resource-based treatment of waste lead paste and fly ash from waste incineration, characterized in that: Raw materials, including waste lead paste, fly ash from waste incineration, and solid fuel, are mixed and formed into briquettes. The resulting briquettes are then dried and roasted sequentially. Lead-containing components are recovered from the roasting flue gas and particulate matter. The remaining solid residue is mainly composed of CaSO4. The roasting temperature is 900~1350℃, and the time is 10~60min. The mass of the solid fuel accounts for 5~15% of the total mass of the raw materials. The mass of the solid fuel is measured by its fixed carbon content.

2. The method for simultaneous harmless and resource-based treatment of waste lead paste and fly ash from waste incineration according to claim 1, characterized in that: The molar ratio of chlorine to lead in the mixture of waste lead paste and waste incineration fly ash satisfies the following condition: n(Cl) / 2n(Pb) is 0.8~1.

1.

3. The method for simultaneous harmless and resource-based treatment of waste lead paste and fly ash from waste incineration according to claim 1, characterized in that: The raw materials also contain a binder with a mass percentage of ≤5%.

4. The method for simultaneous harmless and resource-based treatment of waste lead paste and fly ash from waste incineration according to claim 1, characterized in that: The drying temperature is 80~150℃ and the time is 30~180min.

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