Method for promoting separation and dezincification of blast furnace ash through ultrasonic intensified dissociation

Abstract

The invention relates to a method for promoting separation and dezincification of blast furnace ash through ultrasonic intensified dissociation, which comprises the following steps of: (1) taking a certain amount of blast furnace ash and putting the blast furnace ash into screening equipment for screening to remove large particles on a screen and obtain undersize minerals; (2) taking a certain amount of undersize minerals, adding the undersize minerals into water, uniformly stirring, putting the mixture into ultrasonic equipment, stirring by utilizing ultrasonic waves, filtering and drying to obtain ultrasonically pretreated minerals; (3) weighing a certain amount of the ultrasonically pretreated minerals, adding water for size mixing, and putting the mixture into a hydrocyclone device; collecting the overflow product to obtain a zinc-rich product; and collecting underflow, and filtering and drying to obtain a dezincification product. According to the method, fine-grained minerals adsorbed on the surfaces of large particles can fall off, weak adhesive force among the particles can be destroyed through the cavitation effect of ultrasonic waves so as to promote falling off of zinc-containing particles and enhance the dissociation degree of zinc components in the blast furnace ash, and therefore the separation effect is improved.

Description

Technical Field

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

[0002] Blast furnace bag ash, referred to as blast furnace ash, is dust collected by dry method during steel smelting. As a by-product of the steel industry, its output is huge. One ton of iron will produce about 10 to 100 kilograms of blast furnace ash.

[0003] The main components of blast furnace ash are iron, carbon, zinc, etc., which are treated as solid waste products of steel mills. The common methods are open-air stacking or landfilling, which not only causes waste of metal resources, but also damages the ecological environment. Therefore, the resource processing of blast furnace bag ash is an important manifestation of energy conservation and emission reduction advocated by the country and the realization of repeated utilization of metal resources.

[0004] At present, the main treatment for blast furnace ash in industry is dezincification, so that the dust can be reused as raw material for ironmaking. The dezincification process is mainly divided into pyrolysis and hydrolysis. Although the pyrolysis process has a high dezincification rate, it has a high reduction temperature and high coke consumption, and can generally only process dust ash with a high zinc content, and its operating cost is also relatively high. Although the wet treatment has low energy consumption and low cost, its process is complex, the environmental pollution is large, and the raw material requirements are relatively high. Hydrocyclone pretreatment wet dezincification is the simplest, least investment, smallest footprint, and lowest operating cost process technology among the existing dust ash dezincification recovery technologies, and has good development prospects and value.

[0005] Since the zinc in blast furnace ash mainly exists in the form of zinc oxide, most of it is attached to the surface of other minerals, and a small amount is in the form of monomer piles, especially on the surface of iron-containing particles. Therefore, the dissociation degree of zinc-containing minerals in blast furnace ash is relatively low, which makes the separation efficiency of the pre-treatment wet dezincification process of the hydrocyclone low and the dezincification effect of separation poor. Therefore, how to enhance the dissociation degree of zinc-containing components in blast furnace ash is the difficulty in improving the dezincification effect of separation and realizing the resource utilization of blast furnace ash. Summary of the invention

[0006] 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 sorting process method which combines ultrasonic pretreatment with a hydrocyclone to pretreat blast furnace ash to promote the shedding of zinc-containing particles and enhance the dissociation degree of zinc components in blast furnace ash, thereby promoting the enrichment degree of zinc particles in blast furnace ash to fine particle size to improve the sorting effect. The method also has the advantages of high efficiency, low energy consumption, convenience and speed, so as to be suitable for continuous large-scale application of ultrasonic enhanced dissociation to promote blast furnace ash sorting and dezincification.

[0007] The technical solution adopted by the present invention to solve the above technical problems is: a method for promoting blast furnace ash separation and dezincification by ultrasonic enhanced dissociation, comprising the following steps:

[0008] (1) taking a certain amount of blast furnace ash and placing it in a screening device for screening to remove large particles on the sieve and obtain minerals under the sieve;

[0009] (2) taking a certain amount of the sieve-undertreated mineral and adding it to water, stirring it evenly, placing it in an ultrasonic device to stir it with ultrasonic waves, filtering and drying it to obtain the ultrasonically pretreated mineral;

[0010] (3) Weighing a certain amount of ultrasonically pretreated mineral, adding water to slurry, and placing it in a hydrocyclone device; collecting overflow products to obtain zinc-rich products; collecting underflow, filtering and drying to obtain dezincified products;

[0011] (4) XRF was used to evaluate the dezincification products.

[0012] 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.

[0013] Preferably, the mass ratio of the undersize mineral to water in step (2) is 1:2 to 1:10.

[0014] Preferably, the ultrasonic stirring time of the ultrasonic device in step (2) is 5 to 60 minutes.

[0015] Preferably, the operating frequency of the ultrasonic device in step (2) is 20 to 40 kHz.

[0016] Preferably, the slurry concentration in step (3) is 10 to 25%.

[0017] Preferably, the operating pressure of the hydrocyclone in step (3) is 0.2 MPa.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] (1) The present invention adopts an ultrasonic stirring method to pretreat blast furnace ash, which can not only remove fine-grained minerals adsorbed on the surface of large particles, but also utilize the cavitation effect of ultrasound to destroy the weak adhesion between particles to promote the removal of zinc-containing particles and enhance the dissociation degree of zinc components in blast furnace ash, thereby promoting the enrichment of zinc particles in blast furnace ash to fine particle size, thereby improving the sorting effect.

[0020] (2) The present invention further separates the ultrasonically pretreated minerals through a hydrocyclone, which can effectively separate fine-sized particles in blast furnace ash, thereby achieving efficient separation of zinc-containing components.

[0021] (3) The separation process combining ultrasonic pretreatment with hydrocyclone adopted in the present invention has the advantages of high efficiency, low energy consumption, convenience and speed, and is suitable for continuous large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram of the mineral particle size distribution after ultrasonic stirring and mechanical stirring of blast furnace ash in the present invention;

[0023] Figure 2 This is a cumulative yield trend chart of blast furnace ash subjected to ultrasonic stirring treatment and mechanical stirring treatment according to the present invention;

[0024] Figure 3 The present invention is a comparison diagram of the microscopic morphology changes of Fe and Zn dissociation states after the blast furnace ash is subjected to ultrasonic stirring treatment for 0 minutes, 5 minutes, 10 minutes, 20 minutes and 30 minutes respectively;

[0025] Figure 4 This is a diagram showing the effect of ultrasonic stirring treatment on the dissociation state of Fe and Zn in blast furnace ash in the present invention;

[0026] Figure 5 This is a diagram showing the effect of the separation treatment of the hydrocyclone on the particle size of the blast furnace ash separation product in the present invention. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] A method for promoting separation and dezincification of blast furnace ash by ultrasonic enhanced dissociation, comprising the following steps: Example 1

[0030] (1) Take 1000g of blast furnace ash from a steel plant, and its elemental analysis is shown in Table 1. It can be seen that the blast furnace ash is mainly composed of iron-containing minerals, accounting for 48.5%, and there are also impurity minerals and a small amount of zinc-containing minerals, accounting for 3.64%, which has a high recycling value.

[0031] Table 1 Elemental composition of blast furnace ash

[0032]

[0033] The blast furnace ash is placed in a screening device with a mesh number of 70 to be screened to remove large particles on the screen and obtain minerals under the screen.

[0034] (2) 500 g of the undersize mineral obtained in step (1) is added to 2000 g of water, stirred evenly, and then placed in an ultrasonic device, and ultrasonically stirred for 10 minutes at a frequency of 20 kHz to promote the dissociation of zinc-containing particles, and then filtered and dried to obtain an ultrasonically pretreated mineral.

[0035] (3) Weigh 200 g of the ultrasonically pretreated mineral obtained in step (2), add water to adjust the slurry to a concentration of 20%, place it in a hydrocyclone device, and adjust the inlet pressure to 0.2 MPa; collect the overflow product to obtain a zinc-rich product; collect the underflow, filter and dry it to obtain a dezincified product.

[0036] (4) The dezincification product was evaluated by XRF (X-ray fluorescence spectrometry), and the iron content was 48.7% and the zinc content was 2.6%.

[0037] Example 2

[0038] (1) 1000 g of blast furnace ash from a steel plant was taken, and the blast furnace ash was placed in a screening device with a mesh size of 70 to be screened to remove large particles on the screen and obtain minerals under the screen.

[0039] (2) 500 g of the undersize mineral obtained in step (1) is added to 5000 g of water, stirred evenly, and then placed in an ultrasonic device, and ultrasonically stirred for 60 minutes at a frequency of 40 kHz to promote the dissociation of zinc-containing particles, and then filtered and dried to obtain an ultrasonically pretreated mineral.

[0040] (3) Weigh 200 g of the ultrasonically pretreated mineral obtained in step (2), add water to adjust the slurry to a concentration of 10%, place it in a hydrocyclone device, adjust the inlet pressure to 0.2 MPa, collect the overflow product to obtain a zinc-rich product; collect the underflow, filter and dry it to obtain a dezincified product.

[0041] (4) The dezincification product was evaluated by XRF (X-ray fluorescence spectrometry), and the iron content was 47.9 and the zinc content was 2.8%.

[0042] Example 3

[0043] (1) 1000 g of blast furnace ash from a steel plant was taken, and the blast furnace ash was placed in a screening device with a mesh size of 70 to be screened to remove large particles on the screen and obtain minerals under the screen.

[0044] (2) 500 g of the undersize mineral obtained in step (1) was added to 1000 g of water and stirred evenly. The mixture was then placed in an ultrasonic device and stirred with ultrasound at a frequency of 20 kHz for 5 minutes to promote the dissociation of zinc-containing particles. The mixture was then filtered and dried to obtain an ultrasonically pretreated mineral.

[0045] (3) Weigh 200 g of the ultrasonically pretreated mineral obtained in step (2), add water to adjust the slurry to a concentration of 25%, place it in a hydrocyclone device, adjust the inlet pressure to 0.2 MPa, collect the overflow product to obtain a zinc-rich product; collect the underflow, filter and dry it to obtain a dezincified product.

[0046] (4) The dezincification product was evaluated by XRF (X-ray fluorescence spectrometry), and the iron content was 48.0% and the zinc content was 2.7%.

[0047] Comparative Example 1

[0048] This example is a comparative example of the above-mentioned Example 1, and its purpose is to verify that the degree of promotion of ultrasound on the dissociation of fine-grained minerals in blast furnace ash is beyond the reach of traditional stirring.

[0049] (1) 1000 g of blast furnace ash from a steel plant was taken, and the blast furnace ash was placed in a screening device with a mesh size of 70 to be screened to remove large particles on the screen and obtain minerals under the screen.

[0050] (2) 500 g of the undersize mineral obtained in step (1) was added to 1000 g of water and stirred evenly. The mixture was then placed in a mechanical stirring device and stirred at 400 r / min for 30 minutes. The mixture was then filtered and dried to obtain a stirred pretreated mineral.

[0051] (3) Weigh 200 g of the stirred pretreated mineral obtained in step (2), add water to adjust the slurry to a concentration of 25%, place it in a hydrocyclone device, adjust the inlet pressure to 0.2 MPa, collect the overflow product to obtain a zinc-rich product; collect the underflow, filter and dry it to obtain a dezincified product.

[0052] (4) The dezincification product was evaluated by XRF (X-ray fluorescence spectrometry), and the iron content was 48.6% and the zinc content was 3.1%.

[0053] Comparative Example 2

[0054] This embodiment is a comparative embodiment of the above-mentioned embodiment 1. This embodiment neither uses screening equipment to screen out large particles of minerals, nor uses ultrasonic equipment or mechanical stirring equipment.

[0055] (1) Weigh 200 g of blast furnace ash from a steel plant that is the same as that in Example 1, add water to prepare a slurry with a concentration of 20%, place it in a hydrocyclone device, adjust the inlet pressure to 0.2 MPa, collect the overflow product to obtain a zinc-rich product; collect the underflow, filter and dry it to obtain a dezincified product.

[0056] (2) The dezincification product was evaluated by XRF (X-ray fluorescence spectrometry), and the iron content was 48.8% and the zinc content was 3.1%.

[0057] in conclusion:

[0058] Figure 1 The mineral particle size distribution diagram of the raw mineral after ultrasonic stirring treatment and mechanical stirring treatment. Figure 2 The cumulative yield diagram of the original ore subjected to ultrasonic stirring treatment and mechanical stirring treatment shows that under the traditional mechanical stirring conditions, the particle size distribution and cumulative yield of blast furnace ash are very similar to those of the original ore, indicating that the traditional stirring effect has basically no dissociation effect on the blast furnace ash; but after ultrasonic stirring treatment, the particle size distribution and cumulative yield of blast furnace ash are obviously shifted towards the direction of small particle size, indicating that the ultrasonic stirring treatment promotes the dissociation of fine-particle-size particles of blast furnace ash.

[0059] Figure 3 The following is a comparison of the microscopic morphology of Fe and Zn dissociation states after ultrasonic stirring treatment of blast furnace ash for 0 minutes, 5 minutes, 10 minutes, 20 minutes, and 30 minutes. It can be seen from the figure that after ultrasonic stirring treatment, the number of discrete fine particles in blast furnace ash increased significantly, and the discrete effect gradually improved with the increase of ultrasonic stirring treatment time, which is consistent with the Figure 1 The particle size results are consistent, further proving that the dissociated fine particles are zinc-rich particles.

[0060] Figure 4 This is the EDS statistical analysis result chart. It can be seen that after ultrasonic stirring treatment, the number of zinc monomers in blast furnace ash increases and the number of iron-zinc complexes decreases.

[0061] Figure 5 This is the particle size distribution of the overflow and underflow products of the hydrocyclone. It can be clearly seen that the hydrocyclone can promote the separation of fine particles in blast furnace ash.

[0062] In summary, ultrasonic stirring treatment of blast furnace ash can effectively promote the dissociation of zinc-containing particles and enrich them to fine particle size; in addition, the separation of zinc-containing components can also be achieved through a hydrocyclone.

[0063] 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 blast furnace ash separation and dezincification by ultrasonic enhanced dissociation, characterized in that: The following steps are involved: (1) taking a certain amount of blast furnace ash and placing it in a screening device for screening to remove large particles on the sieve and obtain minerals under the sieve; (2) taking a certain amount of the sieve-undertreated mineral and adding it to water, stirring it evenly, placing it in an ultrasonic device to stir it with ultrasonic waves, filtering and drying it to obtain the ultrasonically pretreated mineral; (3) Weighing a certain amount of ultrasonically pretreated mineral, adding water to slurry, and placing it in a hydrocyclone device; collecting overflow products to obtain zinc-rich products; collecting underflow, filtering and drying to obtain dezincified products; (4) XRF was used to evaluate the dezincification products.

2. The method for promoting blast furnace ash separation and dezincification by ultrasonic enhanced 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 blast furnace ash separation and dezincification by ultrasonic enhanced dissociation according to claim 1, characterized in that: The mass ratio of the undersize mineral to water in step (2) is 1:2 to 1:

10.

4. The method for promoting blast furnace ash separation and dezincification by ultrasonic enhanced dissociation according to claim 1, characterized in that: The ultrasonic stirring time of the ultrasonic equipment in step (2) is 5 to 60 minutes.

5. The method for promoting blast furnace ash separation and dezincification by ultrasonic enhanced dissociation according to claim 1, characterized in that: The operating frequency of the ultrasonic equipment in step (2) is 20 to 40 kHz.

6. The method for promoting blast furnace ash separation and dezincification by ultrasonic enhanced dissociation according to claim 1, characterized in that: The slurry concentration in step (3) is 10-25%.

7. The method for promoting blast furnace ash separation and dezincification by ultrasonic enhanced dissociation according to claim 1, characterized in that: The operating pressure of the hydrocyclone in step (3) is 0.2 MPa.

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