阅读说明：本技术 一种回收含锌固废中锌元素的方法 (Method for recovering zinc element in zinc-containing solid waste ) 是由 于要伟 熊远东 李映 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种回收冶金粉尘中锌元素的方法,如下主要步骤：对原料进行预处理,得到湿压块或混合料,预热干燥后,得到干压块或预热料、尾气；尾气经布袋除尘处理获得成分为CO、CO-(2)的还原性气体；干压块或预热料加入竖炉,通过竖炉加装的微波装置加热至900-1000℃,进行锌氧化物还原,获得脱锌料渣或脱锌粗钢、包含锌蒸汽的烟气；还原性气体通入竖炉辅助锌氧化物还原；包含锌蒸汽的烟气通入冷凝器,冷凝富集,得到液态粗锌与具有余热的烟气；具有余热的烟气通入预热炉,辅助干燥和预热。该方法采用微波加热,降低能耗及成本,循环利用预热炉中产生的尾气以及微波竖炉还原过程产生的烟气,减少气体排放,是一种低碳、高效的从冶金固废中回收锌元素的方法。(The invention discloses a method for recovering zinc element in metallurgical dust, which mainly comprises the following steps: pretreating the raw materials to obtain wet briquettes or mixturesPreheating and drying the materials to obtain dry briquettes or preheated materials and tail gas; the tail gas is subjected to bag-type dust removal treatment to obtain CO and CO as components 2 A reducing gas of (a); adding the dry pressed block or the preheated material into a shaft furnace, heating to 900-; introducing reducing gas into the shaft furnace to assist the reduction of the zinc oxide; introducing the flue gas containing zinc steam into a condenser, condensing and enriching to obtain liquid crude zinc and flue gas with waste heat; and (4) introducing the flue gas with the waste heat into a preheating furnace to assist in drying and preheating. The method adopts microwave heating, reduces energy consumption and cost, recycles tail gas generated in a preheating furnace and flue gas generated in the reduction process of a microwave shaft furnace, reduces gas emission, and is a low-carbon and high-efficiency method for recovering zinc element from metallurgical solid waste.)

1. The method for recovering zinc element in the zinc-containing solid waste is characterized by comprising the following steps:

a, (1) mixing zinc-containing solid waste (such as metallurgical dust) with fine particle size with carbon-containing fine powder and a bonding agent according to a certain proportion, and pouring the mixture into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas;

b. adding the wet briquettes or the mixture into a preheating furnace for drying and preheating to obtain dry briquettes or preheating materials and tail gas;

c. b, performing bag dust removal on the tail gas discharged from the preheating furnace in the step b to obtain main components of CO and CO₂A reducing gas of (a); recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate;

d. b, conveying the dry pressed blocks or the preheated materials obtained in the step b to a material inlet of a shaft furnace, adding the dry pressed blocks or the preheated materials into the shaft furnace by using a screw feeder, heating the dry pressed blocks or the mixed materials to 900-1000 ℃ by using a microwave device additionally arranged on the shaft furnace, carrying out zinc oxide reduction, and obtaining dezincification materials or dezincification crude steel and smoke containing zinc steam;

e. subjecting the dedusted reducing gas (mainly comprising CO and CO) obtained in step c₂) Circularly adding the zinc oxide through an air inlet of the shaft furnace to assist the reduction of the zinc oxide in the dry briquetting or preheating material;

f. d, introducing the flue gas containing the zinc steam obtained in the step d into a condenser, and condensing the zinc steam to obtain liquid crude zinc and dezincification flue gas with waste heat;

g. and f, circularly introducing the dezincification flue gas with the waste heat obtained in the step f into a preheating furnace, and utilizing the rest heat to assist drying and waste heat wet briquetting or mixing materials, so as to reduce energy consumption.

2. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein the zinc-containing solid waste is pretreated differently according to physical properties thereof to have certain metallurgical properties.

3. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein in the step a, the source of the zinc-containing solid waste and the zinc content are not limited.

4. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein in the step a, the gas (tail gas) generated in the preheating furnace from the carbon-containing fine powder is recycled for the whole process flow.

5. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein in the step g, gas (flue gas) discharged from a condenser is recycled for the whole process flow.

6. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein the microwaves are generated by a microwave device installed on said shaft furnace.

7. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein the dry briquettes or the preheated material is added into the shaft furnace by using a screw feeder.

8. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein a cloth bag dust removal process is adopted for dust removal.

9. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein the condenser is used for condensing the zinc element in the flue gas containing zinc steam discharged from the enrichment shaft furnace.

10. The method for recovering zinc element from zinc-containing solid waste according to claim 1, wherein the fly ash generated by the bag-type dust removal process can be recycled as the zinc-containing solid waste, thereby improving the resource utilization rate.

Technical Field

The invention relates to the technical field of shaft furnace reduction dezincification and the field of comprehensive utilization of solid waste, in particular to a method for recovering zinc element in metallurgical solid waste.

Background

Zn is an important metal element widely applied to the industries of alloy manufacture, batteries, ship rust prevention, automobiles, buildings and the like. The replacement of materials in the industries of steel production, non-ferrous metal smelting, automobiles, buildings and the like can generate a large amount of zinc-containing solid wastes (such as metallurgical dust, galvanized steel scrap and the like). The metallurgical dust generated in the metal smelting process is treated by adopting an open-air stacking or direct landfill method, which has great influence on the environment and the ecology. Meanwhile, if galvanized steel scrap produced by replacing materials in the industries of automobiles, buildings and the like is directly added into an electric furnace without being subjected to dezincification treatment, serious corrosion damage can be caused to smelting equipment. Due to technical limitation and economic benefit, a large amount of zinc-containing solid waste is not effectively recycled and utilized at present.

Aiming at the recovery of zinc element in the zinc-containing solid waste, scholars at home and abroad propose various methods, such as a physical method, a wet method, a plasma method, a fire method and the like. The physical method mainly comprises a magnetic separation method and a hydrocyclone separation method, and has the advantages of simple method, low cost and low zinc recovery rate. The wet method mainly recovers zinc element through acid leaching and alkali leaching processes, adopts acid-base solution to separate zinc compound in zinc-containing solid waste, and then recovers the zinc compound through purification, electrolysis and other modes. When the plasma method is used for recovering the zinc element in the zinc-containing solid waste, the process efficiency is higher, the product quality is good, but the problems of high raw material quality requirement, large equipment investment, high energy consumption, short service life of a furnace lining and the like exist. The process for recovering zinc element from zinc-containing solid waste by a pyrogenic process mainly comprises a rotary kiln method, a rotary hearth furnace method and a smelting reduction method, and has the characteristics of long production flow, unstable process, high carbon emission, large environmental pollution, low efficiency, low investment and high operation cost.

With the recent proposal of national targets of 'carbon neutralization' and 'carbon peak reaching', in order to respond national strategies and fulfill national responsibility, the development of an environment-friendly, low-energy-consumption and high-efficiency dezincification process is urgently needed, so that the environment is harmed by zinc-containing solid waste accumulation while the resources are utilized in a green, cyclic and efficient manner.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a method for recovering zinc element from zinc-containing solid waste (including metallurgical dust, galvanized steel scrap and the like) on the premise of cleanness, high efficiency and good economic benefit, so as to reduce resource waste and solve the problem of large accumulation of the zinc-containing solid waste.

In order to achieve the purpose, the invention adopts the following inventive concept:

the invention relates to a method for recovering zinc element in zinc-containing solid waste, which adopts different modes for pretreatment according to the physical properties of raw materials: (1) mixing the zinc-containing solid waste (such as metallurgical dust) with fine particle size, carbon-containing fine powder and binder at a certain ratio, and pouring into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas;

in the zinc-containing solid waste pretreatment (1) and (2), carbon-containing fine powder is heated in the preheating furnace to generate tail gas; the tail gas discharged from the preheating furnace is subjected to bag-type dust removal treatment to obtain main components of CO and CO₂A reducing gas of (a); recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate;conveying the dry pressing block or the preheating material to a material inlet of a shaft furnace, adding the dry pressing block or the preheating material into the shaft furnace by using a screw feeder, heating the dry pressing block or the preheating material to 900-1000 ℃ by using a microwave device additionally arranged on the shaft furnace, and carrying out zinc oxide reduction to obtain a dezincification material or dezincification rough steel and smoke containing zinc steam; treating the tail gas discharged from the preheating furnace by using the bag-type dust collector to obtain the reducing gas (the main components of which are CO and CO)₂) Introducing the gas inlet of the shaft furnace, adding the gas inlet into the shaft furnace to assist the reduction of the zinc oxide, and improving the reduction rate of the zinc oxide; introducing the flue gas containing the zinc steam into an air inlet of a condenser, condensing and enriching the zinc steam contained in the flue gas in the condenser to obtain liquid crude zinc and flue gas with waste heat; introducing the flue gas with the waste heat into an air inlet of the preheating furnace, and drying and preheating the wet briquettes or the mixture by using the rest heat; and treating the flue gas with the waste heat as a zinc-containing raw material and the tail gas by the bag-type dust collector, and introducing the treated flue gas into the shaft furnace to circularly enrich uncondensed zinc steam and improve the recovery rate of zinc.

The method utilizes microwave (clean energy) to heat the shaft furnace, thereby reducing energy consumption and cost; the method has the advantages that the carbon-containing fine powder is used as a main reducing agent, tail gas generated by heat of the carbon-containing fine powder in a preheating furnace and flue gas generated in the reduction process of the microwave shaft furnace are recycled, gas emission is reduced, environmental pollution is avoided, carbon emission of the whole process is reduced, the zinc recovery rate is improved, and the method is a low-carbon and high-efficiency method for recovering zinc element from metallurgical solid waste.

According to the inventive concept, the invention adopts the following technical scheme:

a method for recovering zinc element in metallurgical dust comprises the following steps:

a, (1) mixing zinc-containing solid waste (such as metallurgical dust) with fine particle size with carbon-containing fine powder and a bonding agent according to a certain proportion, and pouring the mixture into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas;

b. adding the wet briquettes or the mixture into a preheating furnace for drying and preheating to obtain dry briquettes or preheating materials and tail gas;

c. b, performing bag dust removal on the tail gas discharged from the preheating furnace in the step b to obtain main components of CO and CO₂A reducing gas of (a); recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate;

d. b, conveying the dry pressed blocks or the preheated materials obtained in the step b to a material inlet of a shaft furnace, adding the dry pressed blocks or the preheated materials into the shaft furnace by using a screw feeder, heating the dry pressed blocks or the mixed materials to 900-1000 ℃ by using a microwave device additionally arranged on the shaft furnace, carrying out zinc oxide reduction, and obtaining dezincification materials or dezincification crude steel and smoke containing zinc steam;

e. subjecting the dedusted reducing gas (mainly comprising CO and CO) obtained in step c₂) Circularly adding the zinc oxide through an air inlet of the shaft furnace to assist the reduction of the zinc oxide in the dry briquetting or preheating material;

f. d, introducing the flue gas containing the zinc steam obtained in the step d into a condenser, and condensing the zinc steam to obtain liquid crude zinc and dezincification flue gas with waste heat;

g. and f, circularly introducing the dezincification flue gas with the waste heat obtained in the step f into a preheating furnace, and utilizing the rest heat to assist drying and waste heat wet briquetting or mixing materials, so as to reduce energy consumption.

Preferably, in the step a, the source of the zinc-containing solid waste and the content of zinc element thereof are not limited.

Preferably, in the step a, the zinc-containing solid waste with fine particle size, the carbon-containing fine powder and the binder are mixed according to a certain proportion, wet briquettes are obtained through cold pressing, and dry briquettes with certain strength and certain metallurgical property are obtained after the wet briquettes are dried.

Preferably, the flue gas with the waste heat is taken as a zinc-containing raw material and is treated by the bag-type dust collector together with the tail gas, and then the flue gas and the tail gas are introduced into the shaft furnace, so that uncondensed zinc steam is circularly enriched, and the recovery rate of zinc is improved.

Preferably, the microwaves are generated by microwave means mounted on said shaft furnace. The microwave is clean energy, has uniform heat transfer and high heating efficiency, and can effectively improve the industrial production efficiency of the method.

Preferably, a screw feeder is used to feed dry briquettes or pre-heated material into the shaft furnace.

Preferably, the dust removal adopts a bag dust removal process.

Compared with the prior art, the invention has the following obvious substantive characteristics and obvious advantages:

1. the method adopts a cold pressing consolidation process to treat the zinc-containing solid waste (metallurgical dust) with fine particle size, so that the zinc-containing solid waste has certain strength and certain metallurgical performance;

2. the method recycles the tail gas generated in the processes of wet briquetting and drying and preheating the mixture and the flue gas generated in the process of microwave reduction of the shaft furnace, avoids environmental pollution and heat energy loss caused by tail gas emission, improves the utilization rate of raw materials, reduces the production cost and energy consumption, and reduces carbon emission;

3. the method of the invention is additionally provided with the microwave generating device on the basis of the shaft furnace, utilizes the microwave as a main heat source, is easy for industrialization, has low equipment investment cost, reduces energy consumption and improves the recovery efficiency of zinc element.

Drawings

FIG. 1 is a schematic flow chart of a method of a preferred embodiment of the present invention.

FIG. 2 is a process flow and gas circulation path diagram of the method of the preferred embodiment of the invention.

Fig. 3 is a schematic structural diagram of the apparatus according to the preferred embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise specifically stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly and may include, for example, a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, and a communication between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The first embodiment is as follows:

in this embodiment, as shown in fig. 1, the method of the present invention comprises the following steps:

a, (1) mixing zinc-containing solid waste (such as metallurgical dust) with fine particle size with carbon-containing fine powder and a bonding agent according to a certain proportion, and pouring the mixture into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas;

b. adding the wet briquettes or the mixture into a preheating furnace for drying and preheating to obtain dry briquettes or preheating materials and tail gas;

c. b, performing bag-type dust removal on the tail gas discharged from the preheating furnace in the step b to obtain reducing gas with main components of CO and CO 2; recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate;

d. b, conveying the dry pressed blocks or the preheated materials obtained in the step b to a material inlet of a shaft furnace, adding the dry pressed blocks or the preheated materials into the shaft furnace by using a screw feeder, heating the dry pressed blocks or the mixed materials to 900-1000 ℃ by using a microwave device additionally arranged on the shaft furnace, carrying out zinc oxide reduction, and obtaining dezincification materials or dezincification crude steel and smoke containing zinc steam;

e. c, circularly adding the dedusted reducing gas (the main components of which comprise CO and CO2) obtained in the step c through an air inlet of the shaft furnace to assist the reduction of zinc oxide in the dry briquettes or the preheated materials;

f. d, introducing the flue gas containing the zinc steam obtained in the step d into a condenser, and condensing the zinc steam to obtain liquid crude zinc and dezincification flue gas with waste heat;

g. and f, circularly introducing the dezincification flue gas with the waste heat obtained in the step f into a preheating furnace, and utilizing the rest heat to assist drying and waste heat wet briquetting or mixing materials, so as to reduce energy consumption.

And treating the flue gas with the waste heat as a zinc-containing raw material and the tail gas by the bag-type dust collector, and introducing the treated flue gas into the shaft furnace to circularly enrich uncondensed zinc steam and improve the recovery rate of zinc.

The method of the invention recycles the gas generated in the metallurgical dust treatment process, avoids the environmental pollution and the heat energy loss caused by the tail gas emission, reduces the carbon emission, improves the utilization rate of the raw materials, reduces the production cost and the energy consumption, and obviously improves the recovery rate of the zinc element by combining the microwave dezincification process.

Example two:

the present embodiment is a diagram of the process stages and gas circulation paths, as shown in fig. 2, and is characterized in that:

pretreating by adopting different modes according to the physical properties of raw materials: (1) mixing the zinc-containing solid waste (such as metallurgical dust) with fine particle size, carbon-containing fine powder and binder at a certain ratio, and pouring into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas;

in the zinc-containing solid waste pretreatment (1) and (2), carbon-containing fine powder is heated in the preheating furnace to generate tail gas; the tail gas discharged from the preheating furnace is subjected to bag-type dust removal treatment to obtain main components of CO and CO₂A reducing gas of (a); recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate; conveying the dry pressing block or the preheating material to a material inlet of a shaft furnace, adding the dry pressing block or the preheating material into the shaft furnace by using a screw feeder, heating the dry pressing block or the preheating material to 900-1000 ℃ by using a microwave device additionally arranged on the shaft furnace, and carrying out zinc oxide reduction to obtain a dezincification material or dezincification rough steel and smoke containing zinc steam; treating the tail gas discharged from the preheating furnace by using the bag-type dust collector to obtain the reducing gas (the main components of which are CO and CO)₂) Introducing the gas inlet of the shaft furnace, adding the gas inlet into the shaft furnace to assist the reduction of the zinc oxide, and improving the reduction rate of the zinc oxide; introducing the flue gas containing the zinc steam into an air inlet of a condenser, condensing and enriching the zinc steam contained in the flue gas in the condenser to obtain liquid crude zinc and flue gas with waste heat; introducing the flue gas with the waste heat into an air inlet of the preheating furnace, and drying and preheating the wet briquettes or the mixture by using the rest heat; and treating the flue gas with the waste heat as a zinc-containing raw material and the tail gas by the bag-type dust collector, and introducing the treated flue gas into the shaft furnace to circularly enrich uncondensed zinc steam and improve the recovery rate of zinc.

The method for recovering zinc element from metallurgical dust and the specific steps of gas circulation in the process flow are described in detail with reference to fig. 2.

Step S1: pretreatment and dry preheating of zinc-containing solid waste

Pretreating by adopting different modes according to the physical properties of raw materials: (1) mixing the zinc-containing solid waste (such as metallurgical dust) with fine particle size, carbon-containing fine powder and binder at a certain ratio, and pouring into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas; the tail gas discharged from the preheating furnace is subjected to bag-type dust removal treatment to obtain main components of CO and CO₂A reducing gas of (a); recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate;

in the embodiment, the galvanized steel scrap is directly mixed with the carbon-containing fine powder to form a mixture, or zinc-containing solid waste with fine particle size is mixed with the carbon-containing fine powder and the adhesive according to a certain proportion, wet briquettes are obtained through cold pressing, and dry briquettes with certain strength and certain metallurgical property are obtained after the wet briquettes are dried, so that the charging amount of raw materials can be effectively increased, and the production efficiency is improved; the source and the zinc content of the zinc-containing solid waste are not limited, so that the requirement of the method on raw materials is reduced, and the universality of the method is improved; tail gas generated in the processes of drying by the preheating furnace and preheating the wet briquetting or mixture is treated by a cloth bag dust removal process, particles in the tail gas can be effectively filtered, and the dust removal efficiency is higher compared with dust removers such as an electric dust remover, a Venturi dust remover, a water film cyclone dust remover and a cyclone dust remover;

step S2: reduction in a microwave shaft furnace

Conveying the dry pressing block or the preheating material to a material inlet of a shaft furnace, adding the dry pressing block or the preheating material into the shaft furnace by using a screw feeder, heating the dry pressing block or the preheating material to 900-1000 ℃ by using a microwave device additionally arranged on the shaft furnace, and carrying out zinc oxide reduction to obtain a dezincification material or dezincification rough steel and smoke containing zinc steam; the preheating grateThe discharged tail gas is treated by the bag-type dust collector to obtain the reducing gas (the main components are CO and CO)₂) Introducing the gas inlet of the shaft furnace, adding the gas inlet into the shaft furnace to assist the reduction of the zinc oxide, and improving the reduction rate of the zinc oxide;

the microwave is a clean energy source, the heat transfer is uniform, the activation energy of the reduction reaction of the zinc oxide is reduced through the molecules of the activation reaction, and the speed of the reduction reaction is improved, so that the conversion speed of the zinc oxide in the reduction process of the shaft furnace is improved, the industrial productivity is improved, and the energy consumption can be reduced on the basis of environmental friendliness by heating the shaft furnace through the microwave; in the process of reducing zinc oxide by the microwave shaft furnace, the carbon-containing fine powder mixed with metallurgical dust and briquetted in the step S1 is used as a main reducing agent, and the main components obtained after tail gas is subjected to cloth bag dust removal treatment are CO and CO₂The reducing gas of (2) to improve the reduction efficiency of the zinc oxide; the method recycles the gas generated in the drying and preheating processes, and obviously reduces gas emission, carbon emission and energy consumption;

step S3: condensing and recovering liquid crude zinc

Introducing the flue gas containing the zinc steam into an air inlet of a condenser, condensing and enriching the zinc steam contained in the flue gas in the condenser to obtain liquid crude zinc and flue gas with waste heat;

introducing the flue gas with the waste heat into an air inlet of the preheating furnace, and drying and preheating the wet briquettes or the mixture by using the rest heat; and treating the flue gas with the waste heat as a zinc-containing raw material and the tail gas by the bag-type dust collector, and introducing the treated flue gas into the shaft furnace to circularly enrich uncondensed zinc steam and improve the recovery rate of zinc.

Example three:

the present embodiment is a schematic structural diagram of the apparatus of the method of the invention, as shown in fig. 3, and is characterized in that:

in this embodiment, in order to implement the method for recovering zinc from metallurgical dust, the implementation of the method will be described in detail with reference to the apparatus for recovering zinc from metallurgical dust shown in fig. 3. The equipment for recovering zinc from metallurgical dust described below is only one specific example of the method for recovering zinc from metallurgical dust according to the above-described embodiment of the present invention, and it is not understood that the method for recovering zinc from metallurgical dust according to the embodiment of the present invention must be exclusively implemented using the equipment described below.

The equipment for recovering zinc element in metallurgical dust comprises: cold press 10, preheater 20, sack cleaner 30, shaft furnace 40, condenser 50, screw feeder 60.

The cold press 10 has a feed inlet 11 and a discharge outlet 12, as described in detail below. The preheating furnace 20 is provided with a feeding hole 21, a discharging hole 22, a preheating furnace gas inlet 23 and a preheating furnace tail gas outlet 24. The bag-type dust collector 30 has a dust collector inlet 31 and a dust collector outlet 32. The shaft furnace 40 has a charging port 41, a shaft furnace discharge port 42, a shaft furnace gas inlet 43, a shaft furnace gas outlet 44, and a microwave device 45. The condenser 50 has a condenser air inlet 51, a condenser air outlet 52, and a crude zinc discharge outlet 53. After metallurgical dust, carbon-containing fine powder and a binder are mixed according to a certain proportion, the mixture is added into a cold press from a feed inlet 11 of the cold press 10, and wet briquettes are prepared and then discharged from a discharge outlet 12 of the cold press 10. The wet briquettes are conveyed to a feed port 21 of a preheating furnace 20 through a belt, and are added into the preheating furnace 20 from the feed port 21 of the preheating furnace 20 to be dried and preheated, and after a certain time, dry briquettes and tail gas are obtained. The dry briquettes are discharged from the discharge port 22 of the preheating furnace 20, transported to the feed port 41 of the shaft furnace 40 through a belt, and added into the shaft furnace 40 equipped with the microwave generating device 45 by using the screw feeder 60. The tail gas is discharged from the gas outlet 24 of the preheating furnace 20, is transported to the gas inlet 31 of the dust collector of the bag-type dust collector 30 through a pipeline, enters from the gas inlet 31 of the dust collector, and is subjected to bag-type dust collection treatment to obtain the main components of CO and CO₂The reducing gas is discharged from a gas outlet 32 of a dust collector of the bag-type dust collector 30, the reducing gas is transported to a gas inlet 43 of a shaft furnace 40 through a pipeline and is circularly added into the shaft furnace 40, a microwave generating device 45 additionally arranged on the shaft furnace 40 heats the shaft furnace 40, carbon-containing fine powder in dry briquettes is used as a main reducing agent, and the reducing gas assists in carrying out microwave reduction on zinc oxide to obtain dezincification slag and flue gas containing zinc steam. The dezincification slag is discharged from a discharge port 42 of the shaft furnace and collected, and the flue gas containing zinc vapor is discharged from a gas outlet 44 of the shaft furnace 40 through a pipeThe zinc vapor enters the condenser 50 from the condenser air inlet 51, and after being condensed and enriched in the condenser 50, dezincification flue gas and liquid zinc are obtained, and the liquid zinc is discharged and collected through a crude zinc discharge port 53 of the condenser 50. The dezincification flue gas is discharged from a condenser air outlet 52 of the condenser 50, enters the preheating furnace 20 from a preheating furnace air inlet 23 of the preheating furnace 20 through a pipeline, and is used for assisting in drying and heating wet briquettes in the preheating furnace 20, so that the energy utilization efficiency is improved.

Reference in the above description to the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. And the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In summary, the invention provides a method for recovering zinc element in metallurgical dust, which comprises the following main steps: pretreating by adopting different modes according to the physical properties of raw materials: (1) mixing the zinc-containing solid waste (such as metallurgical dust) with fine particle size, carbon-containing fine powder and binder at a certain ratio, and pouring into a cold press to prepare wet briquettes; conveying the wet briquettes to a preheating furnace for drying and preheating to obtain dry briquettes and tail gas with higher strength; (2) directly mixing zinc-containing solid waste (such as galvanized steel scrap) with certain strength with carbon-containing fine powder to obtain a mixture, and conveying the mixture to a preheating furnace for preheating to obtain a preheating material and tail gas;

in the zinc-containing solid waste pretreatment (1) and (2), carbon-containing fine powder is heated in the preheating furnace to generate tail gas; the tail gas discharged from the preheating furnace is subjected to bag-type dust removal treatment to obtain main components of CO and CO₂A reducing gas of (a); recycling the dedusting ash obtained by bag dedusting as a raw material, thereby improving the resource utilization rate; transporting the dry briquettes or the pre-heated material to a shaft furnaceA feeding port, wherein the feeding port is added into the shaft furnace by using a screw feeder, the dry pressing block or the preheating material is heated to 900-; treating the tail gas discharged from the preheating furnace by using the bag-type dust collector to obtain the reducing gas (the main components of which are CO and CO)₂) Introducing the gas inlet of the shaft furnace, adding the gas inlet into the shaft furnace to assist the reduction of the zinc oxide, and improving the reduction rate of the zinc oxide; introducing the flue gas containing the zinc steam into an air inlet of a condenser, condensing and enriching the zinc steam contained in the flue gas in the condenser to obtain liquid crude zinc and flue gas with waste heat; introducing the flue gas with the waste heat into an air inlet of the preheating furnace, and drying and preheating the wet briquettes or the mixture by using the rest heat; and treating the flue gas with the waste heat as a zinc-containing raw material and the tail gas by the bag-type dust collector, and introducing the treated flue gas into the shaft furnace to circularly enrich uncondensed zinc steam and improve the recovery rate of zinc.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made according to the purpose of the invention, and any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention should be replaced with equivalents as long as the object of the present invention is met, and the technical principle and the inventive concept of the present invention are not departed from the scope of the present invention.