Intelligent screening process for low-silicon silicon slag

Abstract

The invention discloses a low-silicon silicon slag intelligent screening process, which belongs to the technical field of silicon slag screening, and comprises the following steps: step 1, carrying out preliminary crushing treatment on silicon slag; 2, the crushed silicon slag is transferred into a screening machine to be screened into large-particle-grade silicon slag, medium-particle-grade silicon slag and small-particle-grade silicon slag; 3, transferring the small-size silicon slag into a tailing surge bin for storage, and transferring the large-size silicon slag into the step 1 for crushing treatment again; and fourthly, the medium-grade silicon slag is transferred into a first-grade sorting machine to be subjected to sorting treatment to obtain first-grade low-silicon alloy and tailings, the tailings are transferred into a tailings buffering bin to be stored, and the first-grade low-silicon alloy is transferred into a second-grade sorting machine to be subjected to sorting treatment to obtain second-grade low-silicon alloy and third-grade low-silicon alloy. According to the process provided by the invention, the low-silicon alloy in the silicon slag and the silicon slag can be quickly and efficiently separated and recycled, the recovery of low-silicon alloy resources in the silicon slag is realized, the enterprise benefit is improved, and meanwhile, the resource waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon slag screening, and in particular to an intelligent screening process for low-silicon silicon slag. Background Art

[0002] Silicon alloys include ferrosilicon alloys, industrial silicon, silicon-barium alloys, silicon-calcium alloys, etc. Among them, ferrosilicon alloys, silicon-barium alloys and silicon-barium alloys are mainly used as alloy additives for steelmaking, steel casting, foundry industry and other production of high-quality steel, low-carbon steel, stainless steel, cast steel, etc. Industrial silicon is mainly used as the basic raw material of silicon-aluminum and silicon-based alloys, organic silicon, and polysilicon. Its downstream applications are in the information industry, new energy and other related industries. Silicon alloys are widely used and in great demand.

[0003] During the production of silicon alloys, about 70kg of silicon slag is produced for every ton of silicon alloys produced. The silicon slag contains low-silicon alloys and has good recycling value. At present, silicon alloy production companies deal with silicon slag by selling a small amount of high-quality silicon slag to cement and refractory materials factories, and most of the poor-quality silicon slag is landfilled, which wastes resources and has a serious impact on the environment.

[0004] In the prior art, patent CN217616779U uses a color sorter to sort silicon slag crushed between 2 and 10 mm, and uses the photoelectric sensor in the color sorter to automatically extract the multi-dimensional characteristics of the silicon slag material such as texture, shape, color, texture, and gloss. The control system separates the tailings from the material through a compressed air nozzle to achieve the sorting of low-silicon alloys and slag. However, the problem is that the color sorting accuracy of the color sorter is related to the material processing capacity, the movement speed of the conveyor belt, and the color difference between the target screening object and other materials in the raw materials. Silicon slag screening has the characteristics of large processing capacity and low color difference between low-silicon alloys and slag, which leads to the need to set up multiple color sorters for multiple screening processes, which has the disadvantages of long screening process and high investment cost.

[0005] Patent CN116947050A uses sodium silicate and caustic soda to prepare a solution with a density of 1.04-1.15 kg / m3 to react with silicon slag produced during the industrial silicon smelting process. The elemental silicon floats up with the chemical reaction and overflows into the separator, and the tailings fall to the bottom of the sedimentation space to achieve the separation of elemental silicon and tailings. The elemental silicon content in the recovered product is 90.1%, and the elemental silicon content in the tailings is 5.6%. This method can effectively separate elemental silicon and tailings, but it has the disadvantages of large amounts of sodium silicate and caustic soda, large water consumption, and large amount of wastewater treatment. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides an intelligent screening process for low-silicon silicon slag, which can quickly and efficiently separate and reuse the low-silicon alloy and slag in the silicon slag produced in the process of smelting silicon-based alloys in a submerged arc furnace, thereby realizing the recovery of low-silicon alloy resources in the silicon slag, bringing good benefits to enterprise production and reducing resource waste.

[0007] The technical solution of the present invention is as follows:

[0008] In a first aspect of the present invention, a low-silicon silicon slag intelligent screening process is provided, comprising:

[0009] Step 1, preliminary crushing of silicon slag;

[0010] Step 2: The crushed silicon slag is transported to a screening machine through a transport mechanism for screening into large-sized silicon slag, medium-sized silicon slag and small-sized silicon slag;

[0011] Step 3, transferring the small-sized silicon slag to a tailings buffer bin for storage, and transferring the large-sized silicon slag to step 1 for crushing again;

[0012] Step 4: Transfer the medium-sized silicon slag to a first-level sorting machine for sorting into a first-level low-silicon alloy and tailings, transfer the tailings to a tailings buffer bin for storage, and transfer the first-level low-silicon alloy to a second-level sorting machine for sorting into a second-level low-silicon alloy and a third-level low-silicon alloy.

[0013] In some embodiments of the present invention, the step one is specifically: sending the silicon slag produced during the smelting process of the electric arc furnace to a crusher through a receiving hopper for crushing.

[0014] In some embodiments of the present invention, the crusher is one of a jaw crusher, a roll crusher and a cone crusher.

[0015] In some embodiments of the present invention, the particle size of the large-size silicon slag is greater than 10 mm; the particle size of the medium-size silicon slag is 5 to 10 mm; and the particle size of the small-size silicon slag is 0 to 5 mm.

[0016] In some embodiments of the present invention, the screening machine adopts one of a circular vibrating screen, a linear vibrating screen, and an equal-thickness screen.

[0017] In some embodiments of the present invention, both the primary sorting machine and the secondary sorting machine are X-ray sorting machines.

[0018] In some embodiments of the present invention, the metal silicon content of the tailings is less than the metal silicon content of the primary low-silicon alloy.

[0019] In some embodiments of the present invention, the metal silicon content of the secondary low-silicon alloy is greater than that of the primary low-silicon alloy; the metal silicon content of the tertiary low-silicon alloy is greater than that of the secondary low-silicon alloy.

[0020] In some embodiments of the present invention, the X-ray sorter can set the threshold for separation of primary low-silicon alloy and tailings, as well as the threshold for separation of secondary low-silicon alloy and tertiary low-silicon alloy according to the metallic silicon content in the silicon slag through the control system of the X-ray sorter.

[0021] In some embodiments of the present invention, the transport mechanism uses a belt conveyor to transport the silicon slag.

[0022] One or more technical solutions of the present invention have the following beneficial effects:

[0023] The low-silicon silicon slag intelligent screening process provided by the present invention can quickly and efficiently separate and reuse the low-silicon alloy and slag in the silicon slag produced in the process of smelting silicon-based alloys in a submerged arc furnace, thereby realizing the recovery of low-silicon alloy resources in the silicon slag. By adopting the control system of an X-ray sorting machine to set different silicon slag separation thresholds, silicon slag with different metallic silicon contents can be intelligently sorted, with low human participation, thus bringing good benefits to enterprise production and reducing resource waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a process flow chart of a low-silicon silicon slag intelligent screening process provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0026] Example 1

[0027] In a typical embodiment of the present invention, a low-silicon silicon slag intelligent screening process is proposed, comprising:

[0028] Step 1, preliminary crushing of silicon slag;

[0029] Step 2: The crushed silicon slag is transported to a screening machine through a transport mechanism for screening into large-sized silicon slag, medium-sized silicon slag and small-sized silicon slag;

[0030] Step 3, transferring the small-sized silicon slag to a tailings buffer bin for storage, and transferring the large-sized silicon slag to step 1 for crushing again;

[0031] Step 4: Transfer the medium-sized silicon slag to a first-level sorting machine for sorting into a first-level low-silicon alloy and tailings, transfer the tailings to a tailings buffer bin for storage, and transfer the first-level low-silicon alloy to a second-level sorting machine for sorting into a second-level low-silicon alloy and a third-level low-silicon alloy.

[0032] Furthermore, the step one is specifically as follows: sending the silicon slag produced during the smelting process of the electric arc furnace to a crusher through a receiving hopper for crushing.

[0033] Furthermore, the crusher is one of a jaw crusher, a roll crusher and a cone crusher.

[0034] In this embodiment, the molten silicon slag produced in the process of smelting silicon alloy in the ore-fired furnace exists in a block form after slagging and cooling, and has a large particle size, and needs to be crushed and screened. The silicon slag is crushed once by one of a jaw crusher, a roll crusher, and a cone crusher.

[0035] Furthermore, the particle size of the large-size silicon slag is greater than 10 mm; the particle size of the medium-size silicon slag is 5 to 10 mm; and the particle size of the small-size silicon slag is 0 to 5 mm.

[0036] Furthermore, the screening machine adopts one of a circular vibrating screen, a linear vibrating screen, and an equal-thickness screen.

[0037] In this embodiment, the silicon slag after the first crushing treatment is transported by a belt conveyor to the screening process, and the silicon slag is screened by one of a circular vibrating screen, a linear vibrating screen, and an equal-thickness screen into small-grade silicon slag with a particle size of 0-5 mm, medium-grade silicon slag with a particle size of 5-10 mm, and large-grade silicon slag with a particle size greater than 10 mm. The small-grade silicon slag is transported by a belt conveyor to a tailings buffer bin for storage, and then transported to a building materials manufacturing plant; the medium-grade silicon slag is transported by a belt conveyor to a medium-grade silicon slag buffer bin for storage, and then transported by a belt conveyor to the sorting process for processing, and the large-grade silicon slag returns to the crushing process for crushing again.

[0038] Furthermore, both the primary sorting machine and the secondary sorting machine are X-ray sorting machines.

[0039] Furthermore, the metal silicon content of the tailings is less than that of the primary low-silicon alloy. In this embodiment, the tailings are silicon slag with a metal silicon content of less than 35%; the primary low-silicon alloy is silicon slag with a metal silicon content of more than 35%.

[0040] Furthermore, the metal silicon content of the secondary low-silicon alloy is greater than that of the primary low-silicon alloy; the metal silicon content of the tertiary low-silicon alloy is greater than that of the secondary low-silicon alloy. In this embodiment, the secondary low-silicon alloy is silicon slag with a metal silicon content of 35%-60%; the tertiary low-silicon alloy is silicon slag with a metal silicon content greater than or equal to 60%.

[0041] Furthermore, the X-ray sorter can set the threshold for separation of the primary low-silicon alloy and tailings, and the threshold for separation of the secondary low-silicon alloy and the tertiary low-silicon alloy according to the metallic silicon content in the silicon slag through the control system of the X-ray sorter.

[0042] Furthermore, the transfer mechanism uses a belt conveyor to transfer the silicon slag.

[0043] In this embodiment, the medium-sized silicon slag after screening is fed to the belt conveyor through the vibrating feeder under the medium-sized silicon slag buffer bin, and is transported by the belt conveyor to the first-level X-ray sorter for first-level screening. The silicon slag is transmission scanned by X-rays, and the target value of the metallic silicon content of the first-level X-ray sorter is set. The screening system of the first-level X-ray sorter transmits the scanning result to the control system, and the first-level low-silicon alloy with a metallic silicon content greater than or equal to 35% is blown into the belt conveyor by the compressed air sprayed by the spray valve device and transported to the second-level silicon slag screening process. The tailings with a metallic silicon content less than 35% are thrown onto the belt conveyor and transported to the tailings buffer bin for storage.

[0044] After the primary screening process, the primary low-silicon alloy with a metallic silicon content greater than or equal to 35% is transported to the secondary X-ray sorter for screening via a belt conveyor. The secondary X-ray sorter is set to a threshold for separating the secondary low-silicon alloy and the tertiary low-silicon alloy at a metallic silicon content greater than or equal to 60%. The primary low-silicon alloy is sorted into: a tertiary low-silicon alloy with a metallic silicon content greater than or equal to 60%; and a secondary low-silicon alloy with a metallic silicon content greater than or equal to 35% and less than 60%, thereby achieving graded recovery of low-silicon alloys.

[0045] The silicon slag from the ore-arc furnace provided by a domestic ferrosilicon production enterprise was taken as the treatment object, and the main chemical composition of the silicon slag is shown in Table 1. 100 kg of silicon slag was weighed and sent to a jaw crusher (model: PE600×900) for a crushing process. The crushed material was transported to a circular vibrating screen (model 4YA1540) by a belt conveyor for screening. After screening, the small-sized silicon slag of 0 to 5 mm was 31.26 kg, the medium-sized silicon slag of 5 to 10 mm was 47.39 kg, and the large-sized silicon slag greater than 10 mm was 21.35 kg. The large-sized silicon slag was returned to the jaw crusher (model: PE600×900) for a second crushing and screening process. The treated material was mixed with the material of the same size after the first crushing. After mixing, the small-sized silicon slag was 36.33 kg, and the medium-sized silicon slag was 63.67 kg.

[0046] The 63.67kg medium-sized silicon slag crushed and screened was sent to the first-level X-ray sorter for screening. The separation threshold of the first-level X-ray sorter was set to a metal silicon content greater than or equal to 35%. After the screening was completed, the tailings with a metal silicon content less than 35% were 16.39kg, and the first-level low-silicon alloy content greater than or equal to 35% was 47.27kg. The first-level low-silicon alloy material with a metal silicon content greater than or equal to 35% was screened in the second-level X-ray sorter. The separation threshold of the second-level X-ray sorter was set to a metal silicon content greater than or equal to 60%. After the screening was completed, the second-level low-silicon alloy content with a metal silicon content greater than or equal to 35% and less than 60% was 15.87kg, and the third-level low-silicon alloy content greater than or equal to 60% was 22.05kg.

[0047] The secondary low-silicon alloy screened out by the secondary X-ray sorter accounts for 22.05%, the tertiary low-silicon alloy accounts for 15.87%, and the tailings after screening and 0-5mm small-particle silicon slag account for 62.08% in total. The main chemical compositions of the low-silicon alloy and tailings are shown in Table 1.

[0048] Table 1 Main chemical element composition (%) of silicon slag produced by a domestic ferrosilicon plant and its products after separation and treatment

[0049] element Si TFe Al Ca C S Small-sized silicon slag 37.78 36.88 7.31 11.40 6.21 0.17 Three-grade low silicon alloy 73.12 20.60 2.41 2.67 0.875 0.02 Secondary low silicon alloy 48.05 28.39 6.67 10.27 6.28 0.14 Tailings 21.59 21.37 8.80 14.13 7.73 0.22

[0050] Example 2

[0051] The classification treatment of the obtained silicon slag can be adjusted according to actual needs to obtain graded silicon slag with different metallic silicon contents.

[0052] The silicon slag from the ore-melting furnace provided by a domestic industrial silicon production enterprise was taken as the treatment object, and the main chemical composition of the silicon slag is shown in Table 1. 100 kg of silicon slag was weighed and sent to a jaw crusher (model: PE600×900) for a crushing process. The crushed material was transported to a circular vibrating screen (model 4YA1540) by a belt conveyor for screening. After screening, the small-scale silicon slag with a particle size of 0 to 5 mm was 28.56 kg, the medium-scale silicon slag with a particle size of 5 to 10 mm was 42.38 kg, and the large-scale silicon slag with a particle size greater than 10 mm was 29.06 kg. The large-scale silicon slag was returned to the jaw crusher (model: PE600×900) for a second crushing and screening process. The treated material was mixed with the material of the same particle size after the first crushing. After mixing, the small-scale silicon slag was 40.39 kg, and the medium-scale silicon slag was 59.61 kg.

[0053] The 59.61kg medium-sized silicon slag crushed and screened was sent to the first-level X-ray sorter for screening. The separation threshold of the first-level X-ray sorter was set to a metal silicon content greater than or equal to 60%. After the screening was completed, the tailings with a metal silicon content less than 60% were 35.43kg, and the first-level low-silicon alloy with a metal silicon content greater than or equal to 60% was 16.33kg. The first-level low-silicon alloy material with a metal silicon content greater than or equal to 60% was transported to the second-level X-ray sorter for screening. The separation threshold of the second-level X-ray sorter was set to a metal silicon content greater than or equal to 80%. After the screening was completed, the metal silicon content was greater than or equal to 60%, the second-level low-silicon alloy content less than 80% was 16.33kg, and the third-level low-silicon alloy content greater than or equal to 80% was 7.85kg.

[0054] The third-level low-silicon alloy screened out by the secondary X-ray sorter accounts for 7.85%, the second-level low-silicon alloy accounts for 16.33%, and the tailings after screening and small-sized silicon slag between 0 and 5 mm account for 75.82% in total. The main chemical compositions of the low-silicon alloy and tailings are shown in Table 1.

[0055] Table 2 Main chemical element composition (%) of silicon slag produced by a domestic industrial silicon plant and its products after screening and treatment

[0056] element <![CDATA[SiO2]]> SiC Si <![CDATA[Al2O3]]> CaO MgO Small-sized silicon slag 29.69 6.55 27.50 19.02 15.06 0.69 Three-grade low silicon alloy 5.85 2.03 82.63 3.26 2.55 0.33 Secondary low silicon alloy 10.65 3.3 64.57 10.36 9.37 0.50 Tailings 42.30 9.01 16.11 26.28 20.50 0.89

[0057] The low-silicon silicon slag intelligent screening process provided by the present invention can quickly and efficiently separate and reuse the low-silicon alloy and slag in the silicon slag produced during the smelting of silicon-based alloys in a submerged arc furnace, thereby realizing the recovery of the low-silicon alloy resources in the silicon slag, bringing good benefits to the production of the enterprise and reducing resource waste.

[0058] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A low-silicon silicon slag intelligent screening process, characterized in that: include: Step 1, putting silicon slag into a crusher for preliminary crushing; Step 2: The crushed silicon slag is transported to a screening machine through a transport mechanism for screening into large-sized silicon slag, medium-sized silicon slag and small-sized silicon slag; Step 3, transferring the small-sized silicon slag to a tailings buffer bin for storage, and transferring the large-sized silicon slag to step 1 for crushing again; Step 4: Transfer the medium-sized silicon slag to a first-level sorting machine for sorting into a first-level low-silicon alloy and tailings, transfer the tailings to a tailings buffer bin for storage, and transfer the first-level low-silicon alloy to a second-level sorting machine for sorting into a second-level low-silicon alloy and a third-level low-silicon alloy.

2. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The step 1 is specifically as follows: the silicon slag produced during the smelting process of the electric arc furnace is sent to the crusher through the receiving hopper for crushing.

3. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The crusher is one of a jaw crusher, a roll crusher and a cone crusher.

4. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The particle size of the large-size silicon slag is greater than 10 mm; the particle size of the medium-size silicon slag is 5 to 10 mm; and the particle size of the small-size silicon slag is 0 to 5 mm.

5. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The screening machine adopts one of a circular vibrating screen, a linear vibrating screen and an equal thickness screen.

6. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The primary sorting machine and the secondary sorting machine both adopt X-ray sorting machines.

7. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The metal silicon content of the tailings is less than the metal silicon content of the primary low-silicon alloy.

8. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The metal silicon content of the secondary low-silicon alloy is greater than that of the primary low-silicon alloy; the metal silicon content of the tertiary low-silicon alloy is greater than that of the secondary low-silicon alloy.

9. The low-silicon silicon slag intelligent screening process according to claim 6, characterized in that: The X-ray sorter can set the threshold for separation of the primary low-silicon alloy and tailings, and the threshold for separation of the secondary low-silicon alloy and the tertiary low-silicon alloy according to the metallic silicon content in the silicon slag through the control system of the X-ray sorter.

10. The low-silicon silicon slag intelligent screening process according to claim 1, characterized in that: The transfer mechanism uses a belt conveyor to transfer the silicon slag.

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