Method for promoting dezincification of blast furnace ash through ore grinding intensified dissociation

Abstract

The invention relates to a method for promoting dezincification of blast furnace ash through ore grinding intensified dissociation, which comprises the following steps: (1) screening blast furnace ash in screening equipment, and removing a small amount of large particles on a screen to obtain a screened substrate; (2) taking a certain amount of the screened substrate, adding water for size mixing, and carrying out primary Zn removal by virtue of a hydrocyclone, so as to obtain a hydrocyclone substrate; (3) taking a certain amount of the cyclone substrate, adding the cyclone substrate into water to carry out size mixing, then putting the cyclone substrate into a flotation machine, adding a flotation reagent to carry out flotation, and removing flotation concentrate foam to obtain a flotation substrate cyclone liquid; (4) the flotation substrate rotational flow liquid is placed in a ball mill to be ground, and ball-milled turbid liquid is obtained; and (5) the ball-milling suspension is placed in a flotation machine, a flotation reagent is added, flotation concentrate foam is removed, and tailings are filtered, washed and dried. According to the method, resource utilization of the blast furnace ash is achieved, investment is small, operation cost is low, and cost reduction and efficiency improvement can be achieved for enterprises to a great extent.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, and in particular to a method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation. Background Art

[0002] China's steel industry is huge in scale, and its position and role in the national economy are very important, and are directly related to the country's infrastructure construction and national defense security. A large amount of solid waste will be generated in the steel production process. The resource utilization of solid waste can achieve the goal of CO2 emission reduction, and at the same time can effectively reduce environmental pollution and alleviate resource shortages. Especially in order to achieve the goals of carbon peak and carbon neutrality, the steel industry needs to accelerate technological transformation and green transformation.

[0003] Blast furnace bag dust collection ash is a by-product of the blast furnace ironmaking process, referred to as blast furnace ash, which is rich in Fe, C, Zn and other components and has a high utilization value; the resource recycling of blast furnace ash in my country's steel mills will save a large amount of iron ore, carbon and zinc resources, and is of great significance to improving resource utilization efficiency of steel mills, promoting energy conservation, carbon reduction and efficiency improvement, and improving green and low-carbon circular development.

[0004] The most convenient way to utilize blast furnace bag dust is to return it directly to sintering. However, due to the low melting point of Zn, zinc enrichment is easily formed during the sintering process with the continuous addition of new raw materials, and the zinc load of the blast furnace increases, which has an adverse effect on the life of the blast furnace lining, the heat flow distribution of the blast furnace and the energy consumption of the blast furnace. Therefore, it is necessary to remove the Zn in the blast furnace bag dust and reuse it.

[0005] The resource utilization methods of blast furnace bag dust removal ash mainly include pyrometallurgical process, hydrometallurgical process and physical separation process; the pyrometallurgical process has large equipment investment and high operating energy consumption, and is suitable for ash with high Zn content; the hydrometallurgical process has a low leaching rate, a long treatment process, severe equipment corrosion, and the treatment volume is difficult to meet large-scale applications; the physical separation process has the characteristics of low investment and high separation efficiency.

[0006] When Fe and C products are recovered from blast furnace bag ash and returned for sintering, strict requirements are placed on their Zn content (generally, the Zn content is less than 0.5%). However, the current physical separation process mainly focuses on the effective separation of Fe, C and Zn in bag dust removal ash, ignoring the requirement for ultra-low Zn content in the recovered components, making it difficult to meet the return sintering index. Therefore, the development of a method for recycling blast furnace ash with ultra-low Zn content is of great significance to energy conservation and consumption reduction in steel enterprises. Summary of the invention

[0007] In view of the current status of the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a method for promoting the dezincification of blast furnace ash by grinding and strengthening dissociation, which is suitable for large-scale promotion, and can also provide a method for reducing the Zn content of the recovered components in the blast furnace bag ash to an extremely low level (0.5%) so as to meet the requirement of returning to the blast furnace for further sintering, thereby realizing the resource utilization of blast furnace ash, and strengthening the dissociation of Zn components on the surface of Fe particles to have the advantage of low operating cost, thereby greatly reducing costs and increasing efficiency for enterprises, so as to achieve large-scale promotion of grinding and strengthening dissociation to promote dezincification of blast furnace ash.

[0008] The technical solution adopted by the present invention to solve the above technical problems is: a method for promoting blast furnace ash dezincification by grinding enhanced dissociation, comprising the following steps:

[0009] (1) placing blast furnace ash in a screening device for screening, removing a small amount of large particles on the sieve, and obtaining a screening substrate;

[0010] (2) taking a certain amount of the screened substrate and adding water to prepare a slurry, and then performing primary Zn removal with the aid of a hydrocyclone, screening and drying the overflow product to obtain a fine particle Zn-rich product; collecting the underflow, filtering and drying, and obtaining a cyclone substrate;

[0011] (3) taking a certain amount of cyclone substrate, adding it to water for slurry preparation, then placing it in a flotation machine and adding a flotation agent for flotation, removing the flotation concentrate foam, and obtaining a flotation substrate cyclone liquid;

[0012] (4) grinding the flotation substrate cyclone liquid in a ball mill to obtain a ball-milled suspension;

[0013] (5) Place the ball mill suspension in a flotation machine and add flotation reagents to remove the froth of the flotation concentrate, and filter, rinse and dry the tailings.

[0014] Preferably, the screening device in step (1) is one of a fixed screen, a cylindrical screen, a linear vibrating screen, a rotary vibrating screen, an air flow screen, and a shaking screen; and the screen mesh number of the screening device in step (1) is 70 meshes.

[0015] Preferably, the slurry concentration of the sieved substrate in step (2) is 10-30%, and the pressure of the hydrocyclone in step (2) is 0.2 MPa.

[0016] Preferably, the slurry concentration of the cyclone substrate in step (3) is 10 to 30%.

[0017] Preferably, the flotation reagents in step (3) include a sulfiding agent, an inhibitor, an activator, a collector and a frother; the sulfiding agent is sodium sulfide; the inhibitor is one or more of water glass, sodium hexametaphosphate, and carboxymethyl starch; the activator is copper sulfate; the collector is butyl xanthate; and the frother is No. 2 oil.

[0018] Preferably, the amount of the vulcanizing agent is 1000-4000 g / t blast furnace ash, the amount of the inhibitor is 150-3000 g / t blast furnace ash, the amount of the activator is 300-800 g / t blast furnace ash, the amount of the collector is 400-1000 g / t blast furnace ash, and the amount of the foaming agent is 10-50 g / t blast furnace ash.

[0019] Preferably, the grinding time of the ball mill in step (4) is 5 to 60 minutes, and the rotation speed of the ball mill is 400 to 900 r / min.

[0020] Preferably, the flotation reagent in step (5) comprises a collector and a frother, the collector is butyl xanthate, and the frother is pinene alcohol.

[0021] Preferably, the amount of the collector in step (5) is 200-600 g / t blast furnace ash, and the amount of the foaming agent in step (5) is 10-20 g / t blast furnace ash.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] (1) The present invention adopts the process of cyclone + flotation to remove Zn, and reduces the Zn content of the recovered components in the blast furnace bag ash to an extremely low level (0.5%), thereby meeting the requirement of returning to the blast furnace for continued sintering, thereby realizing the resource utilization of blast furnace ash.

[0024] (2) The present invention uses a hydrocyclone to complete the first-stage Zn removal to avoid affecting subsequent flotation operations, thereby reducing the consumption of flotation reagents and thus reducing operating costs.

[0025] (3) The present invention also adds a grinding operation to perform the second stage of Zn removal, thereby reducing the particle size of the flotation ash and strengthening the dissociation of the Zn-containing components on the surface of the Fe particles, which is beneficial to improving the flotation Zn removal effect. The grinding operation is also placed between the two flotation operations, thereby effectively reducing the grinding amount, thereby reducing energy consumption, and further reducing the operating cost.

[0026] (4) The present invention has the advantages of low investment and low operating cost, which will greatly reduce costs and increase efficiency for enterprises and is suitable for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a process flow chart of Example 1 of the present invention;

[0028] Figure 2 It is the component distribution diagram of Fe and Zn in the blast furnace ash of the present invention;

[0029] Figure 3 It is a process flow chart of Comparative Example 1 of the present invention;

[0030] Figure 4 It is a process flow chart of Comparative Example 2 of the present invention;

[0031] Figure 5 This is a relationship diagram of the effect of the grinding operation on the particle size of blast furnace ash in the present invention;

[0032] Figure 6 The figure is a relationship diagram showing the influence of the grinding operation of the present invention on the dissociation degree of Fe and Zn in blast furnace ash. DETAILED DESCRIPTION

[0033] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0034] In order to keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of well-known functions and well-known components are omitted.

[0035] Example 1

[0036] like Figure 1 As shown, a method for grinding and strengthening dissociation to promote dezincification of blast furnace ash comprises the following steps:

[0037] (1) 200 g of blast furnace ash (element composition as shown in Table 1 and Figure 2 The product is placed in a 70-mesh screening device for screening, and a small amount of large particles on the screen are removed to avoid affecting the subsequent process, thereby obtaining a screening substrate; the screening device is one of a fixed screen, a cylindrical screen, a linear vibrating screen, a rotary vibrating screen, an airflow screen, and a shaking screen.

[0038] (2) 100 g of the sieved substrate in step (1) was added with water to prepare a slurry with a concentration of 20%, and primary Zn removal was performed by means of a hydrocyclone, and the inlet pressure of the hydrocyclone was adjusted to 0.2 MPa; the overflow product was sieved and dried to obtain a fine particle Zn-rich product; the underflow was collected, filtered and dried to obtain a cyclone substrate.

[0039] (3) 100 g of the cyclone substrate in step (2) was added into water for slurry preparation to a concentration of 20%, stirred evenly, placed in a flotation machine, and the following amounts of flotation reagents were added: sulfiding agent (300 mg of sodium sulfide), inhibitor (100 mg of water glass), inhibitor (200 mg of sodium hexametaphosphate), inhibitor (15 mg of carboxymethyl starch), activator (50 mg of copper sulfate), collector (80 mg of butyl xanthate) and frother (3 mg of No. 2 oil) for flotation; the flotation concentrate foam was removed to obtain a flotation substrate cyclone liquid.

[0040] The inhibitor is one or more of water glass, sodium hexametaphosphate and carboxymethyl starch.

[0041] (4) The flotation substrate cyclone liquid of step (3) is placed in a ball mill and ground for 20 minutes at a rotation speed of 650 r / min. After the grinding, a ball mill suspension is obtained, the purpose of which is to strengthen the separation of Fe-Zn conjoined bodies and increase the dissociation degree of the Zn component.

[0042] (5) The ball-milled suspension in step (4) is placed in a flotation machine, and the following flotation reagents are added: a collector (40 mg of butyl xanthate) and a frother (1.5 mg of pinene alcohol); the flotation concentrate foam is removed, and the tailings are filtered, rinsed, and dried to obtain a tailings recovery rate of 45.6%, wherein the Fe content is 67.2% and the Zn content is 0.5%.

[0043] Example 2

[0044] A method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation, comprising the following steps:

[0045] (1) 200 g of blast furnace ash (element composition as shown in Table 1 and Figure 2 The product is placed in a 70-mesh screening device for screening, and a small amount of large particles on the screen are removed to avoid affecting the subsequent process, thereby obtaining a screening substrate; the screening device is one of a fixed screen, a cylindrical screen, a linear vibrating screen, a rotary vibrating screen, an airflow screen, and a shaking screen.

[0046] (2) 100 g of the sieved substrate in step (1) was added with water to prepare a slurry with a concentration of 10%, and primary Zn removal was performed by means of a hydrocyclone, and the inlet pressure of the hydrocyclone was adjusted to 0.2 MPa; the overflow product was sieved and dried to obtain a fine particle Zn-rich product; the underflow was collected, filtered and dried to obtain a cyclone substrate.

[0047] (3) 100 g of the cyclone substrate in step (2) was added into water for slurry preparation to a concentration of 10%, stirred evenly, placed in a flotation machine, and the following amounts of flotation reagents were added: sulfiding agent (100 mg of sodium sulfide), inhibitor (15 mg of water glass), activator (50 mg of copper sulfate), collector (40 mg of butyl xanthate) and frother (1 mg of No. 2 oil) for flotation; the flotation concentrate foam was removed to obtain a flotation substrate cyclone liquid.

[0048] The inhibitor is one or more of water glass, sodium hexametaphosphate and carboxymethyl starch.

[0049] (4) The flotation substrate cyclone liquid of step (3) is placed in a ball mill and ground for 5 minutes at a rotation speed of 400 r / min. After the grinding, a ball mill suspension is obtained, the purpose of which is to strengthen the separation of Fe-Zn conjoined bodies and increase the dissociation degree of the Zn component.

[0050] (5) The ball-milled suspension in step (4) is placed in a flotation machine, and the following flotation reagents are added: a collector (20 mg of butyl xanthate) and a frother (1 mg of pinene alcohol); the flotation concentrate foam is removed, and the tailings are filtered, rinsed, and dried to obtain a tailings recovery rate of 37.6%, wherein the Fe content is 53.2% and the Zn content is 1.8%.

[0051] Example 3

[0052] A method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation, comprising the following steps:

[0053] (1) 200 g of blast furnace ash (element composition as shown in Table 1 and Figure 2 The product is placed in a 70-mesh screening device for screening, and a small amount of large particles on the screen are removed to avoid affecting the subsequent process, thereby obtaining a screening substrate; the screening device is one of a fixed screen, a cylindrical screen, a linear vibrating screen, a rotary vibrating screen, an airflow screen, and a shaking screen.

[0054] (2) 100 g of the sieved substrate in step (1) was added with water to prepare a slurry with a concentration of 30%, and primary Zn removal was performed by means of a hydrocyclone, and the inlet pressure of the hydrocyclone was adjusted to 0.2 MPa; the overflow product was sieved and dried to obtain a fine particle Zn-rich product; the underflow was collected, filtered and dried to obtain a cyclone substrate.

[0055] (3) 100 g of the cyclone substrate in step (2) was taken, added into water for slurry preparation, the concentration of which was 20%, stirred evenly, placed in a flotation machine, and the following amounts of flotation reagents were added: sulfiding agent (sodium sulfide 400 mg), inhibitor (sodium hexametaphosphate 300 mg), activator (copper sulfate 80 mg), collector (butyl xanthate 100 mg) and frother (No. 2 oil 5 mg) for flotation; the flotation concentrate foam was removed to obtain a flotation substrate cyclone liquid.

[0056] The inhibitor is one or more of water glass, sodium hexametaphosphate and carboxymethyl starch.

[0057] (4) The flotation substrate cyclone liquid of step (3) is placed in a ball mill and ground for 60 minutes at a rotation speed of 900 r / min. After the grinding, a ball mill suspension is obtained, the purpose of which is to strengthen the separation of Fe-Zn conjoined bodies and increase the dissociation degree of the Zn component.

[0058] (5) The ball-milled suspension in step (4) is placed in a flotation machine, and the following flotation reagents are added: a collector (60 mg of butyl xanthate) and a frother (2 mg of pinene alcohol); the flotation concentrate foam is removed, and the tailings are filtered, rinsed, and dried to obtain a tailings recovery rate of 44.5%, wherein the Fe content is 55.8%, and the Zn content is 1.3%.

[0059] Table 1 Element composition of the raw ore

[0060]

[0061] Comparative Example 1

[0062] This embodiment is a comparative embodiment of embodiment 1, except that the grinding treatment in step (4) is not performed in this embodiment. The operation flow is as follows: Figure 3 As shown, the tailings yield is 48.8%, the iron oxide content is 70.3%, and the zinc oxide content is 1.5%.

[0063] Comparative Example 2

[0064] This embodiment is a comparative embodiment of embodiment 1. The difference is that in this embodiment, the grinding process in step (4) is moved before the two flotation operations. The operation process is as follows: Figure 4 As shown, the tailings yield is 45.5%, the iron oxide content is 71.9%, and the zinc oxide content is 1.36%.

[0065] Conclusion: If Figure 5 , Figure 6As shown in the figure, moving the grinding process between the two flotation operations can effectively enhance the dissociation of Zn-Fe conjoined bodies, which can not only enrich the Fe component, but also reduce the Zn content in the recovered blast furnace bag dust removal ash to an extremely low level (0.5%), meeting the requirement of directly returning it to the blast furnace for sintering; in addition, it can also reduce the particle size of the flotation ash and enhance the dissociation of the Zn-containing components on the surface of the Fe particles, which is beneficial to improving the flotation removal Zn effect.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation, characterized in that: The following steps are involved: (1) placing blast furnace ash in a screening device for screening, removing a small amount of large particles on the sieve, and obtaining a screening substrate; (2) taking a certain amount of the screened substrate and adding water to prepare the slurry, and then performing primary Zn removal with the aid of a hydrocyclone, screening and drying the overflow product to obtain a fine particle Zn-rich product; Collect the bottom flow, filter and dry to obtain the cyclone bottom; (3) taking a certain amount of cyclone substrate, adding it to water for slurry preparation, then placing it in a flotation machine and adding a flotation agent for flotation, removing the flotation concentrate foam, and obtaining a flotation substrate cyclone liquid; (4) grinding the flotation substrate cyclone liquid in a ball mill to obtain a ball-milled suspension; (5) Place the ball mill suspension in a flotation machine and add flotation reagents to remove the froth of the flotation concentrate, and filter, rinse and dry the tailings.

2. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 1, characterized in that: The screening device in step (1) is one of a fixed screen, a cylindrical screen, a linear vibrating screen, a rotary vibrating screen, an air flow screen, and a shaking screen; the screen mesh number of the screening device in step (1) is 70 meshes.

3. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 1, characterized in that: The slurry concentration of the sieved substrate in step (2) is 10-30%, and the pressure of the hydrocyclone in step (2) is 0.2 MPa.

4. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 1, characterized in that: The slurry concentration of the cyclone bottom in step (3) is 10-30%.

5. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 1, characterized in that: The flotation reagents in step (3) include a sulfiding agent, an inhibitor, an activator, a collector and a frother; the sulfiding agent is sodium sulfide; the inhibitor is one or more of water glass, sodium hexametaphosphate, and carboxymethyl starch; the activator is copper sulfate; the collector is butyl xanthate; and the frother is No. 2 oil.

6. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 5, characterized in that: The dosage of the vulcanizing agent is 1000-4000 g / t blast furnace ash, the dosage of the inhibitor is 150-3000 g / t blast furnace ash, the dosage of the activator is 300-800 g / t blast furnace ash, the dosage of the collector is 400-1000 g / t blast furnace ash, and the dosage of the foaming agent is 10-50 g / t blast furnace ash.

7. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 1, characterized in that: The grinding time of the ball mill in step (4) is 5 to 60 minutes, and the rotation speed of the ball mill is 400 to 900 r / min.

8. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 1, characterized in that: The flotation reagent in step (5) includes a collector and a frother, wherein the collector is butyl xanthate and the frother is pinene alcohol.

9. The method for promoting dezincification of blast furnace ash by grinding and strengthening dissociation according to claim 8, characterized in that: The amount of the collector in step (5) is 200-600 g / t of blast furnace ash, and the amount of the foaming agent in step (5) is 10-20 g / t of blast furnace ash.

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