CN110433956B

CN110433956B - Method for recovering zinc, iron and/or carbon from blast furnace gas ash

Info

Publication number: CN110433956B
Application number: CN201910754389.1A
Authority: CN
Inventors: 李金惠; 马黎阳; 余嘉栋; 曹明锋; 林琳; 王健月
Original assignee: Tangshan Xinlian Environmental Protection Technology Co ltd
Current assignee: Tangshan Xinlian Environmental Protection Technology Co ltd
Priority date: 2019-08-15
Filing date: 2019-08-15
Publication date: 2021-04-20
Anticipated expiration: 2039-08-15
Also published as: CN110433956A

Abstract

The invention provides a method for recovering zinc, iron and/or carbon from blast furnace gas ash, which comprises the following steps: preparing blast furnace gas ash into ore pulp, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the particle size of less than 0.025mm and iron-containing and carbon-containing materials with the particle size of more than 0.025 mm; and carrying out spiral separation on the obtained iron and carbon-containing materials, and dehydrating after separation to obtain carbon products and iron products. The invention divides the blast furnace gas ash into zinc-containing particles and iron-and carbon-containing materials through 0.025 mm-level wet screening, selects spiral sorting to sort the iron and the carbon according to the density difference of the iron and the carbon and the granularity characteristics of the iron-and carbon-containing materials, thereby realizing the separation and recovery of the zinc, the iron and/or the carbon in the blast furnace gas ash, the zinc content in the zinc-rich product reaches 6.01 wt%, the iron content in the iron product reaches 50.45 wt%, and the carbon content in the carbon product reaches 51.14 wt%.

Description

Method for recovering zinc, iron and/or carbon from blast furnace gas ash

Technical Field

The invention belongs to the technical field of resource recovery, relates to a method for recovering resources from blast furnace gas ash, and particularly relates to a method for recovering zinc, iron and/or carbon from blast furnace gas ash.

Background

The blast furnace gas ash refers to a fine particle group discharged along with blast furnace gas in a blast furnace steelmaking process, is fine solid particles formed by incomplete combustion of minerals, and usually contains 5-15 wt% of metallic zinc, 15-40 wt% of metallic iron, 25-50% of non-metallic carbon and the balance of other elements.

Because of the technical limitation at present, the blast furnace gas ash is one of the inevitable solid excrement in the blast furnace smelting process at present, a large amount of blast furnace gas ash to be treated still exists at present, the effective recovery of the blast furnace gas ash can relieve the resource pressure of zinc and iron, reduce the harm of resource shortage, and also can reduce the stacking harm of the blast furnace gas ash.

At present, the recovery method of blast furnace gas recovery mainly comprises a beneficiation enrichment method, a hydrometallurgy method and a high-temperature smelting method.

CN 107604110A discloses a method for selecting iron from blast furnace gas ash, which comprises the steps of introducing the blast furnace gas ash into an air classification-air magnetic separation system for treatment, and separating large-particle gas ash through air classification to obtain air-separated iron concentrate; separating magnetic materials in the fine-grained gas ash through air magnetic separation to obtain magnetic separation iron ore concentrate, and directly returning the air separation iron ore concentrate and the magnetic separation iron ore concentrate to sintering and smelting processes for use; the secondary gas ash collected by the bag-type dust collector is zinc-rich mineral powder, the method utilizes the matching of the length of the air blower and the length of the air duct to sort and concentrate particles with large granularity and medium quality, and then utilizes a magnetic separation method to recycle metal iron in the materials, the method does not introduce chemical agents and add water, can realize high-efficiency dry sorting, and the recovery rate of iron elements can reach more than 87%.

CN 106011476A discloses a process for extracting scandium from gas ash, wherein the gas ash containing scandium is leached by waste acid and then filtered, the solution obtained after filtration is reduced by a reducing agent and then neutralized by the gas ash containing scandium, the neutralized slag is leached at normal pressure by the waste acid, and the filtrate obtained after leaching is subjected to extraction and back extraction of oxalic acid for precipitation to obtain scandium oxalate. The process uses mixed waste acid consisting of sulfuric acid, hydrochloric acid and nitric acid to carry out acid leaching on the scandium-containing gas ash, and then carries out extraction and back extraction on the leachate to obtain scandium salt and indium salt, thereby recycling rare metals and being capable of simultaneously recycling electro-deposited zinc.

CN 107686895A discloses a comprehensive utilization method of metallurgical solid waste, in the method, iron-carbon-containing zinc dust and mud are added into the slag discharging process of high-temperature slag, sensible heat of the slag and carbon resources in the dust and mud are fully utilized, and the iron and zinc in the high-temperature slag and the dust and mud are subjected to reduction reaction, so that the synchronous recovery of valuable resources such as iron and zinc in the dust and mud and slag is realized; after iron and zinc are removed, high value-added utilization of the residual slag can be realized by controlling the components of the mixed slag and the cooling mode. The method utilizes the residual heat of the blast furnace slag to reach the reaction temperature of carbon reduction, and can effectively reduce energy consumption.

The above methods all alleviate the pressure of blast furnace gas ash on the ecological environment, but there are also problems that need to be improved.

The raw material of the wind magnetic separation is gravity separation and enrichment based on the density difference of metal elements of zinc, iron and lead and non-metal element of carbon in the blast furnace gas ash. Although their density difference satisfies the necessary condition of gravity separation, in the practical application process, the blast furnace gas ash has a small particle size, and the metal element particles and the carbon-containing particles cannot overcome the turbulence influence in the air medium, and only can randomly enter the product tank along with the air flow, so that the content of the mismatch is increased, and the gravity separation effect is deteriorated.

The direct implementation of various forms of hydrometallurgical leaching solutions on blast furnace gas ash has the problem that the leaching solutions are difficult to implement, the gas ash after being treated by blast furnace fire has high carbon content and very good surface hydrophobicity, so that the gas ash can only float on the surface of acid liquor in the leaching process and is difficult to be fully mixed for acid leaching reaction, and if the gas ash and high-temperature furnace slag are remelted, elements such as zinc, lead and the like in the blast furnace gas ash can be changed into impurity elements, thereby affecting the quality of steel products. Therefore, there is a need to provide a method for more rational treatment of blast furnace gas ash.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for jointly recovering zinc, iron and/or carbon from blast furnace gas ash, and the method can respectively obtain particles rich in the three elements of zinc, iron and carbon through a specific physical separation method according to the distribution rule of the three elements of zinc, iron and carbon in the blast furnace gas ash, thereby realizing the separation and recovery of the zinc, iron and/or carbon.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a method for the combined recovery of zinc, iron and/or carbon from blast furnace gas ash, comprising the steps of:

(1) preparing blast furnace gas ash into first ore pulp, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the particle size of less than 0.025mm and iron-containing and carbon-containing materials with the particle size of more than 0.025 mm;

(2) and (2) modulating the iron and carbon-containing material obtained in the step (1) into second ore pulp, carrying out spiral separation treatment, and dehydrating after the spiral separation is finished to obtain a carbon product and an iron product.

The process that different elements in blast furnace gas ash form particles is different, in the blast furnace smelting process, zinc element in the raw materials is reduced at high temperature to form zinc steam, and then the zinc steam and air are oxidized and condensed into zinc-containing particles with small particle size, so that the zinc element is enriched in small micro-particles with the particle size of less than 0.025 mm; the carbon element in the blast furnace gas ash is mainly coke fragments or coal powder discharged from the gas ash after the raw materials are not completely combusted, so the particle size of the carbon-containing particles is larger, the formation reason of the iron-containing particles is more complex, on one hand, the iron-containing particles are generated by gasification, liquefaction and solidification of molten iron in the iron making process, on the other hand, the iron-containing large particles are carried out in the escape process of the gas and the carbon powder, and the content of the iron element in different particle sizes is almost unchanged.

Therefore, the zinc element in the blast furnace gas ash is enriched in the particles with the granularity of less than 0.025mm, the carbon element is enriched in the particles with the granularity of more than 0.025mm, and the content difference of the iron element in each granularity level is not obvious, so the invention can obtain the zinc-containing particles and the iron-and-carbon-containing materials by grading with the granularity of 0.025 mm.

Preferably, the operation of preparing the first ore pulp from the blast furnace ash in the step (1) comprises: mixing blast furnace gas ash with water to obtain first ore pulp.

Preferably, the concentration of the first pulp of step (1) is 20-40 wt%, for example, it may be 20 wt%, 25 wt%, 30 wt%, 35 wt% or 40 wt%, preferably 25-35 wt%.

Preferably, the wet sieving of step (1) is performed in a high frequency sieve.

Preferably, the wet sieving operation of step (1) comprises: and (4) conveying the first ore pulp to a high-frequency screen by using a slurry pump, and carrying out wet screening.

Preferably, the first ore pulp also contains a dispersant.

Preferably, the dispersant comprises any one of or a combination of at least two of hydrolyzed polymaleic anhydride, sodium hexametaphosphate or water glass, typical but non-limiting combinations include hydrolyzed polymaleic anhydride with sodium hexametaphosphate, sodium hexametaphosphate with water glass, hydrolyzed polymaleic anhydride with water glass or hydrolyzed polymaleic anhydride, sodium hexametaphosphate with water glass.

Preferably, the concentration of the dispersant is 0.8 to 1.5 wt%, and may be, for example, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, or 1.5 wt%.

Preferably, the operation of modulating the iron-and-carbon-containing material obtained in the step (1) into the second ore pulp comprises the following steps: mixing iron-containing and carbon-containing materials with water to obtain second ore pulp;

preferably, the concentration of the second pulp is 15-25 wt%, for example 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt% or 25 wt%.

Preferably, the method comprises the step of dehydrating the zinc-containing particles of step (1) to obtain a zinc-rich product.

Preferably, the water obtained after dewatering the zinc-containing particles is used for preparing the first ore pulp and/or the second ore pulp.

Preferably, said spiral screening of step (2) is performed in a spiral classifier.

Preferably, the spiral sorting machine adopts 8 circles of spiral grooves, the outer edge inclination angle is 8 degrees, and the flow velocity in the grooves is 8 r/min.

Since the density of iron is 7.8g/cm³The density of the carbon is 1.8g/cm³The gravity separation technology based on density difference enables good selection of iron and carbon particles to be separated, but the iron and carbon particles are small in size, and the conventional air medium air separation effect is poor.

The invention utilizes a spiral separation method, strengthens the process of separating iron-containing particles and carbon-containing particles according to density by virtue of the stability of a shallow laminar water body, namely, slurry containing iron-containing materials and carbon materials forms the shallow laminar water body in a spiral chute of a spiral separator, the iron-containing particles with high density sink to the bottom of a material layer and move to the outer side of a tank body by virtue of the centrifugal action generated by a spiral water channel, the carbon-containing particles with low density float above the material layer and stay in the tank body, and finally, carbon products and iron products are respectively obtained at the inner side and the outer side of a discharge hole of the spiral separator.

Preferably, the water obtained after the dewatering in the step (2) is used for preparing the first ore pulp and/or the second ore pulp.

As a preferred technical scheme of the method, the method comprises the following steps:

(1) mixing blast furnace gas ash, water and a dispersing agent to prepare a first ore pulp with the concentration of 20-40 wt%, wherein the concentration of the dispersing agent in the first ore pulp is 0.8-1.5 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and carrying out 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;

(2) mixing iron-containing and carbon-containing materials with water to prepare second ore pulp with the concentration of 15-25 wt%, carrying out spiral separation on the second ore pulp in a spiral separator, dewatering after the spiral separation to obtain a carbon product and an iron product, dewatering zinc-containing particles obtained in the step (1) to obtain a zinc-rich product, and using the water obtained by dewatering to prepare the first ore pulp and/or the second ore pulp.

The recitation of numerical ranges herein includes not only the above-recited numerical values, but also any numerical values between non-recited numerical ranges, and is not intended to be exhaustive or to limit the invention to the precise numerical values encompassed within the range for brevity and clarity.

Compared with the prior art, the invention has the beneficial effects that:

the invention divides the blast furnace gas ash into zinc-containing particles and iron-and carbon-containing materials through 0.025 mm-level wet screening, and then selects a spiral sorting method to sort the iron and the carbon according to the density difference of the iron and the carbon and the granularity characteristics of the iron-and carbon-containing materials, thereby realizing the separation and recovery of the zinc, the iron and/or the carbon in the blast furnace gas ash, wherein the zinc content in the zinc-rich product is up to 6.01 wt%, the iron content in the iron product is up to 48.84 wt%, and the carbon content in the carbon product is up to 40.88 wt%. The method is simple and easy to implement and easy to industrially popularize.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

Example 1

The present example provides a process for the combined recovery of zinc, iron and/or carbon from blast furnace gas ash, the process comprising the steps of:

(1) mixing blast furnace gas ash, water and sodium hexametaphosphate to prepare first ore pulp with the concentration of 30 wt%, wherein the concentration of the sodium hexametaphosphate in the first ore pulp is 1 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;

(2) mixing iron-containing and carbon-containing materials with water to prepare a second ore pulp with the concentration of 20 wt%, carrying out spiral separation on the second ore pulp in a spiral separator, dewatering after the spiral separation to obtain a carbon product and an iron product, dewatering zinc-containing particles obtained in the step (1) to obtain a zinc-rich product, and using the water obtained by dewatering to prepare the first ore pulp and/or the second ore pulp.

The elemental composition in the blast furnace gas ash in this example included: 2.18 weight percent of zinc, 31.30 weight percent of iron, 37.27 weight percent of carbon, 5.74 weight percent of chlorine, 1.53 weight percent of water and the balance of other elements.

Zinc-rich products: 6.01 wt% of zinc, 24.19 wt% of iron, 33.07 wt% of carbon, 1.83 wt% of chlorine and the balance of other elements;

iron product: 0.95 wt% of zinc; 50.45 wt% of iron, 19.12 wt% of carbon, 0.93 wt% of chlorine and the balance of other elements;

carbon product: 1.81 wt% of zinc; 20.10 wt% of iron, 51.14 wt% of carbon, 0.75 wt% of chlorine and the balance of other elements.

Example 2

(1) mixing blast furnace gas ash, water and sodium hexametaphosphate to prepare a first ore pulp with the concentration of 25 wt%, wherein the concentration of the sodium hexametaphosphate in the first ore pulp is 0.9 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;

(2) mixing iron-containing and carbon-containing materials with water to prepare a second ore pulp with the concentration of 18 wt%, carrying out spiral separation on the second ore pulp in a spiral separator, dewatering after the spiral separation to obtain a carbon product and an iron product, dewatering the zinc-containing particles obtained in the step (1) to obtain a zinc-rich product, and using the water obtained by dewatering to prepare the first ore pulp and/or the second ore pulp.

Zinc-rich products: 5.68 wt% of zinc, 26.00 wt% of iron, 34.18 wt% of carbon, 1.90 wt% of chlorine and the balance of other elements;

iron product: 1.12 wt% of zinc; 48.63 wt% of iron, 20.23 wt% of carbon, 0.89 wt% of chlorine and the balance of other elements;

carbon product: 1.92 wt% of zinc; 20.52 wt% of iron, 50.01 wt% of carbon, 0.80 wt% of chlorine and the balance of other elements.

Example 3

(1) mixing blast furnace ash, water and hydrolyzed polymaleic anhydride to prepare first ore pulp with the concentration of 35 wt%, wherein the concentration of the hydrolyzed polymaleic anhydride in the first ore pulp is 1.2 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;

(2) mixing iron-containing and carbon-containing materials with water to prepare a second ore pulp with the concentration of 22 wt%, carrying out spiral separation on the second ore pulp in a spiral separator, dewatering after the spiral separation to obtain a carbon product and an iron product, dewatering zinc-containing particles obtained in the step (1) to obtain a zinc-rich product, and using the water obtained by dewatering to prepare the first ore pulp and/or the second ore pulp.

Zinc-rich products: 5.49 wt% of zinc, 26.75 wt% of iron, 33.87 wt% of carbon, 1.88 wt% of chlorine, and the balance of other elements;

iron product: 1.09 wt% of zinc; 47.98 wt% of iron, 21.64 wt% of carbon, 0.98 wt% of chlorine and the balance of other elements;

carbon product: 1.95 wt% of zinc; 20.06 wt% of iron, 49.83 wt% of carbon, 0.82 wt% of chlorine, and the balance of other elements.

Example 4

(1) mixing blast furnace gas ash, water and water glass to prepare a first ore pulp with the concentration of 20 wt%, wherein the concentration of the water glass in the first ore pulp is 0.8 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;

(2) mixing iron-containing and carbon-containing materials with water to prepare second ore pulp with the concentration of 15 wt%, carrying out spiral separation on the second ore pulp in a spiral separator, dewatering after the spiral separation to obtain a carbon product and an iron product, dewatering zinc-containing particles obtained in the step (1) to obtain a zinc-rich product, and using the water obtained by dewatering to prepare the first ore pulp and/or the second ore pulp.

Zinc-rich products: 5.01 wt% of zinc, 28.03 wt% of iron, 34.67 wt% of carbon, 1.95 wt% of chlorine and the balance of other elements;

iron product: 1.23 wt% of zinc; 45.39 wt% of iron, 25.48 wt% of carbon, 0.98 wt% of chlorine and the balance of other elements;

carbon product: 2.01 wt% of zinc; 21.17 wt% of iron, 47.31 wt% of carbon, 0.75 wt% of chlorine and the balance of other elements.

Example 5

(1) mixing blast furnace gas ash, water and sodium hexametaphosphate to prepare first ore pulp with the concentration of 40 wt%, wherein the concentration of the sodium hexametaphosphate in the first ore pulp is 1.5 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;

(2) mixing iron-containing and carbon-containing materials with water to prepare second ore pulp with the concentration of 25 wt%, carrying out spiral separation on the second ore pulp in a spiral separator, dewatering after the spiral separation to obtain a carbon product and an iron product, dewatering zinc-containing particles obtained in the step (1) to obtain a zinc-rich product, and using the water obtained by dewatering to prepare the first ore pulp and/or the second ore pulp.

Zinc-rich products: 4.89 wt% of zinc, 28.52 wt% of iron, 35.22 wt% of carbon, 1.91 wt% of chlorine and the balance of other elements;

iron product: 1.29 wt% of zinc; 45.51 wt% of iron, 26.59 wt% of carbon, 0.91 wt% of chlorine and the balance of other elements;

carbon product: 2.03 wt% of zinc; 21.06 wt% of iron, 46.16 wt% of carbon, 0.83 wt% of chlorine and the balance of other elements.

Example 6

(1) mixing blast furnace gas ash with water to prepare first ore pulp with the concentration of 30 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and carrying out 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-containing and carbon-containing materials with the granularity of more than 0.025 mm;

Zinc-rich products: 4.04 wt% of zinc, 30.51 wt% of iron, 36.61 wt% of carbon, 1.99 wt% of chlorine and the balance of other elements;

iron product: 1.33 wt% of zinc; 44.43 wt% of iron, 31.71 wt% of carbon, 0.95 wt% of chlorine and the balance of other elements;

carbon product: 1.96 wt% of zinc; 23.62 percent of iron, 40.36 percent of carbon, 0.88 percent of chlorine and the balance of other elements.

Comparative example 1

The present comparative example provides a process for the combined recovery of zinc, iron and/or carbon from blast furnace gas ash, the process comprising the steps of:

(1) mixing blast furnace gas ash, water and sodium hexametaphosphate to prepare first ore pulp with the concentration of 30 wt%, wherein the concentration of the sodium hexametaphosphate in the first ore pulp is 1 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.02 mm-grade wet screening to obtain zinc-containing particles with the granularity of less than 0.02mm and iron-and-carbon-containing materials with the granularity of more than 0.02 mm;

The elemental composition of the blast furnace gas ash in this comparative example included: 2.18 weight percent of zinc, 31.30 weight percent of iron, 37.27 weight percent of carbon, 5.74 weight percent of chlorine, 1.53 weight percent of water and the balance of other elements.

Zinc-rich products: 6.14 wt% of zinc, 25.26 wt% of iron, 32.57 wt% of carbon, 1.78 wt% of chlorine and the balance of other elements;

iron product: 1.35 wt% of zinc; 49.15 wt% of iron, 25.13 wt% of carbon, 0.95 wt% of chlorine and the balance of other elements;

carbon product: 1.98 wt% of zinc; 21.68 wt% of iron, 45.23 wt% of carbon, 0.81 wt% of chlorine and the balance of other elements.

Comparative example 2

(1) mixing blast furnace gas ash, water and sodium hexametaphosphate to prepare first ore pulp with the concentration of 30 wt%, wherein the concentration of the sodium hexametaphosphate in the first ore pulp is 1 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.03 mm-grade wet screening to obtain zinc-containing particles with the granularity of less than 0.03mm and iron-and-carbon-containing materials with the granularity of more than 0.03 mm;

The blast furnace gas ash used in examples 1 to 5 and comparative examples 1 to 2 of the present invention is the same batch of blast furnace gas ash, and the blast furnace gas ash comprises the following elements: 2.18 weight percent of zinc, 31.30 weight percent of iron, 37.27 weight percent of carbon, 5.74 weight percent of chlorine, 1.53 weight percent of water and the balance of other elements.

Zinc-rich products: 5.01 wt% of zinc, 30.11 wt% of iron, 34.18 wt% of carbon, 1.84 wt% of chlorine and the balance of other elements;

iron product: 0.91 wt% of zinc; 48.28 wt% of iron, 26.09 wt% of carbon, 1.01 wt% of chlorine and the balance of other elements;

carbon product: 1.83 weight percent of zinc; 19.23 wt% of iron, 46.83 wt% of carbon, 0.85 wt% of chlorine and the balance of other elements.

In conclusion, the blast furnace gas ash is separated into zinc-containing particles and iron-and-carbon-containing materials through 0.025 mm-grade wet screening, and then the iron and the carbon are separated by a spiral separation method according to the density difference of the iron and the carbon and the granularity characteristics of the iron-and-carbon-containing materials, so that the separation and recovery of zinc, iron and/or carbon in the blast furnace gas ash are realized, the content of zinc in a zinc-rich product is up to 6.01 wt%, the content of iron in an iron product is up to 50.45 wt%, and the content of carbon in a carbon product is up to 51.14 wt%. The method is simple and easy to implement and easy to industrially popularize.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recovering zinc, iron and/or carbon from blast furnace gas ash, comprising the steps of:

(1) mixing blast furnace gas ash and water, preparing into a first ore pulp with the concentration of 20-40 wt%, and carrying out 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-containing and carbon materials with the granularity of more than 0.025 mm; the first ore pulp also contains a dispersant with the concentration of 0.8-1.5 wt%;

(2) modulating the iron-and-carbon-containing material obtained in the step (1) into second ore pulp with the concentration of 15-25 wt%, carrying out spiral separation treatment, and dehydrating after the spiral separation is finished to obtain a carbon product and an iron product;

dehydrating the zinc-containing particles obtained in the step (1) to obtain a zinc-rich product; water obtained after the zinc-containing particles are dehydrated is used for preparing first ore pulp and/or second ore pulp;

and (3) the water obtained after the dehydration in the step (2) is used for preparing the first ore pulp and/or the second ore pulp.

2. The process according to claim 1, characterized in that the concentration of the first pulp of step (1) is 25-35 wt%.

3. The method of claim 1 or 2, wherein the wet sieving of step (1) is performed in a high frequency sieve.

4. The method of claim 3, wherein the operation of wet sieving of step (1) comprises: and (4) conveying the first ore pulp to a high-frequency screen by using a slurry pump, and carrying out wet screening.

5. The method of claim 1, wherein the dispersant comprises any one of hydrolyzed polymaleic anhydride, sodium hexametaphosphate, or water glass, or a combination of at least two thereof.

6. The method according to claim 1, wherein the operation of modulating the iron-and carbon-containing material obtained in step (1) into a second pulp comprises: and mixing the iron-containing and carbon-containing materials with water to obtain second ore pulp.

7. The method of claim 1, wherein said spiral sorting of step (2) is performed in a spiral sorter.

8. Method according to claim 1, characterized in that it comprises the following steps:

(1) mixing blast furnace gas ash, water and a dispersing agent to prepare a first ore pulp with the concentration of 20-40 wt%, wherein the concentration of the dispersing agent in the first ore pulp is 0.8-1.5 wt%, conveying the first ore pulp to a high-frequency sieve by using a slurry pump, and performing 0.025 mm-level wet screening to obtain zinc-containing particles with the granularity of less than 0.025mm and iron-and-carbon-containing materials with the granularity of more than 0.025 mm;