A method for producing a vanadium-containing steel slag by dry process

Abstract

The present application relates to waste resource recycling technical field, especially to a kind of method for preparing vanadium-containing steel slag by dry method, comprising the following steps: S1, steel slag material is pre-dried;S2, the steel slag material after drying is screened by first screen mesh, and the material on the screen is crushed by high-pressure roller mill, and the crushed material is screened by first screen mesh, and the material on the screen is returned to high-pressure roller mill for cyclic crushing;S3, the multiple screened material is mixed uniformly by stirring equipment, and the screened powder is screened by second screen mesh, and the granular material on the screen is magnetically separated by first magnetic separator, and the iron-containing material and the remaining material after magnetic separation are magnetically separated by second magnetic separator, and the vanadium-containing steel slag and tailings are magnetically separated.The method of the present application can magnetically separate vanadium-containing steel slag from steel slag material, greatly improve the recovery and utilization rate of vanadium resources in steel slag material, and avoid the waste of vanadium resources.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste resource recycling, and in particular to a method for preparing vanadium-containing steel slag by dry method. BACKGROUND

[0002] Vanadium resources are important strategic resources, and the vanadium resources in Panxi region account for about one-third of the world. Vanadium-titanium magnetite, as one of the three symbiotic minerals, is the main form of existence. After the blast furnace ironmaking and converter vanadium extraction steelmaking, the valuable resource vanadium is effectively extracted, but a small amount of vanadium still exists in the slag. After breaking, screening and magnetic separation to extract valuable elements, 300,000 tons of 0-60mm steel slag material will be formed every year, the V2O5 content is maintained at 1.0-3.0%, and the recovery of vanadium is difficult, which leads to serious waste of vanadium resources. SUMMARY

[0003] The purpose of the present application is to provide a method for preparing vanadium-containing steel slag by dry method, which can magnetically separate vanadium-containing steel slag from steel slag material, greatly improve the recovery and utilization rate of vanadium resources in steel slag material, and avoid the waste of vanadium resources.

[0004] The present application provides a method for preparing vanadium-containing steel slag by dry method, comprising the following steps:

[0005] S1, pre-drying the steel slag material;

[0006] S2, screening the dried steel slag material with a first screen to remove the undersize material, breaking the oversize material with a high-pressure roller mill, and screening the broken material with a first screen, and returning the oversize material to the high-pressure roller mill for cyclic breaking;

[0007] S3, mixing the multiple undersize materials uniformly with a stirring device, screening the undersize powder with a second screen, magnetically separating the oversize granular material with a first magnetic separator to obtain iron-containing material and residual material, and magnetically separating the residual material with a second magnetic separator to obtain vanadium-containing steel slag and tailings.

[0008] The 0-60mm steel slag material is the residual material after screening, breaking and magnetic separation of the converter steel slag, and the indexes are shown in Table 1:

[0009] Table 1 Physical and chemical indexes of steel slag material, %

[0010]

[0011] The V2O5 content in the 0-60mm steel slag material is maintained at 1.0-3.0%, and the recovery of V is difficult, which is mainly present in the granular non-metallic material. In order to obtain V2O5 in the granular state, the powder part needs to be screened out with a suitable screen.

[0012] Preferably, step S1 includes: pre-drying the steel slag material with a moisture content of 8-12% in the 0-60mm range to control the moisture content to below 5%.

[0013] Preferably, the moisture content is controlled below 3%.

[0014] Preferably, step S2 includes: The dried steel slag material is screened using a 3-5mm first screen to remove undersize material. The undersize material enters the feed hopper, while the oversize material enters the feed hopper. The material in the feed hopper is conveyed to the elevator via a first conveyor belt, and then to the high-pressure roller mill hopper. It is necessary to maintain the material in the hopper at a certain height, using the material's own weight to ensure that the feed material is maintained within a certain pressure range. The high-pressure roller mill is used for crushing. By adjusting the transmission speed of the first conveyor belt, the material in the high-pressure roller mill hopper is kept at the same level until crushing is complete. After crushing, the crushed material is screened using a 3-5mm first screen. The oversize material is returned to the high-pressure roller mill for repeated crushing in the above manner. The process of screening the crushed material using a 3-5mm first screen after crushing is repeated.

[0015] Preferably, the feeding hoppers sequentially include: hopper #1, hopper #2, and hopper #3; after the material in hopper #1 is crushed, the material in hopper #2 is crushed, and after the material in hopper #2 is crushed, the material in hopper #3 is crushed.

[0016] Preferably, the feeding hoppers include, in sequence, hoppers #4, #5, #6, #7, #8, and #9; the undersized material is fed from hopper #4 to hopper #9 in sequence, and after hopper #9 has finished feeding, the undersized material screened out during the next round of crushing is fed from hopper #9 to hopper #4 in sequence.

[0017] Preferably, the undersized material is fed from silo #4 to silo #9 via a chute.

[0018] In one specific implementation, step S2 includes:

[0019] S21. The dried steel slag material is screened off by a 3-5mm first screen to remove the undersized material. The undersized material enters the No. 4 silo, and the oversized material enters the No. 1 silo. The material in the No. 1 silo is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill silo for crushing.

[0020] S22. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 5 hopper, and the material on the screen enters the No. 2 hopper. The material in the No. 2 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0021] S23. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 6 hopper, and the material on the screen enters the No. 3 hopper. The material in the No. 3 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0022] S24. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 7 hopper, and the material on the screen enters the No. 1 hopper. The material in the No. 1 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0023] S25. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 8 hopper, and the material on the screen enters the No. 2 hopper. The material in the No. 2 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0024] S26. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 9 hopper, and the material on the screen enters the No. 3 hopper. The material in the No. 3 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0025] S27. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 9 hopper, and the material on the screen enters the No. 1 hopper. The material in the No. 1 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0026] S28. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 8 hopper, and the material on the screen enters the No. 2 hopper. The material in the No. 2 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill.

[0027] S29. The crushed material on the screen is screened off by a 3-5mm first screen to remove the undersize material. The undersize material enters the No. 7 hopper, and the material on the screen enters the No. 3 hopper. The material in the No. 3 hopper is conveyed to the elevator by the first conveyor belt. The elevator then conveys the material to the high-pressure roller mill hopper, where it is crushed by the high-pressure roller mill. The crushing process is then complete.

[0028] Preferably, the first screen is a 3mm screen.

[0029] Preferably, in step S3, a mixer is used to mix the undersize materials from different batches evenly. After mixing, a second screen of 0.5-1mm is used for sieving to remove the undersize powder. The granular material on the screen is then magnetically separated using a first magnetic separator of 800-1000 gauss to select the iron-containing material and the remaining material after magnetic separation. The remaining material is then magnetically separated again using a second magnetic separator of 5000-10000 gauss to select the magnetically separated material and the remaining material after magnetic separation. The magnetically separated material is vanadium-containing steel slag, and the remaining material after magnetic separation is tailings.

[0030] Preferably, step S3 includes:

[0031] S31. Weigh the undersize material in silos 4, 5, 6, 7, 8 and 9 respectively, and calculate the weight ratio of the undersize material.

[0032] S32. Set the feeding speed of materials from hoppers #4 to #9 to the conveyor belt according to the ratio, and transport them to the mixing equipment via the second conveyor belt for uniform mixing;

[0033] S33. Use a second screen of 0.5-1mm to screen out the granular material on the screen and the powder material under the screen;

[0034] S34. The granular material on the screen is magnetically separated by a first magnetic separator with an 800-1000 gauss, and the iron-containing material and the remaining material after magnetic separation are separated.

[0035] S35. The remaining material after magnetic separation is subjected to a second magnetic separator with a speed of 5000-10000 gauss to separate vanadium-containing steel slag and tailings.

[0036] Preferably, the second screen is a 0.5mm screen.

[0037] Preferably, the magnetic field strength of the first magnetic separator is 800 Gauss, and the magnetic field strength of the second magnetic separator is 6000 Gauss.

[0038] Beneficial effects:

[0039] The technical solution of this invention uses a first screen to screen steel slag material. The material above the screen is crushed by a high-pressure roller mill. The material below the screen is screened by a second screen to remove the powder. The granular material above the screen is magnetically separated by a first magnetic separator to remove iron-containing material. The remaining material is magnetically separated again by a second magnetic separator to remove vanadium-containing steel slag. This greatly improves the recovery rate of vanadium resources in steel slag material and avoids the waste of vanadium resources. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a process flow diagram of the dry method for preparing vanadium-containing steel slag according to the present invention. Detailed Implementation

[0042] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] like Figure 1 As shown, this embodiment provides a dry method for obtaining vanadium-containing steel slag, including the following steps:

[0046] (1) The physicochemical properties of steel slag materials with a diameter of 0-60 mm are shown in Table 2:

[0047] Table 2 Physicochemical properties of steel slag materials, %

[0048]

[0049] (2) After the material is dried by the drying equipment, the moisture content is 3.27%.

[0050] (3) Use a 3mm screen to screen it. The material on the screen enters the No. 1 silo, and the material under the screen enters the No. 4 silo.

[0051] (4) The material on the screen of No. 1 silo is conveyed to the elevator by the belt, and the elevator conveys the material to the silo of the high pressure roller mill. By adjusting the transmission speed of the conveyor belt, the material in the silo of the high pressure roller mill is kept at roughly the same level until the crushing is completed.

[0052] (5) The material crushed by the high-pressure roller mill is screened with a 3mm screen. The material on the screen enters the No. 2 silo, and the material under the screen enters the No. 5 silo.

[0053] (6) After the screen material in hopper #1 is completely crushed, crushing of material in hopper #2 will begin.

[0054] (7) The undersized material is fed from the No. 4 silo to the No. 9 silo in sequence, and the oversized material is used alternately in the No. 1, No. 2 and No. 3 silos in sequence.

[0055] (8) During the crushing process, the proportion of undersize material in the next round of crushing gradually decreases. In order to avoid the fact that feeding material from No. 4 to No. 9 in sequence still cannot fully meet the test requirements, after No. 9 is fed, the undersize material screened out in the next round of crushing is fed from No. 9 to No. 4 in sequence. When the material returns to No. 7 for feeding, the material crushing process is completely ended.

[0056] (9) When the crushing and screening is completed, the weight ratio of the material undersize from bins 4 to 9 (4# to 9#) is shown in Table 3, based on the data displayed by the weighing sensor:

[0057] Table 3 Distribution of Undersize Material Proportion

[0058] 4# 5# 6# 7# 8# 9# Total 21.51 19.87 16.78 15.57 14.49 11.78 100.00

[0059] (10) Set the feeding speed of material from No. 4 silo to No. 9 silo to the conveyor belt according to the ratio, and convey it to the mixing equipment through the conveyor belt. Mix for 5 minutes to ensure uniform mixing.

[0060] (11) The well-stirred material is sieved through a 0.5mm sieve to separate granular material and powder.

[0061] (12) Particle materials are separated by an 800 Gauss magnetic separator to remove iron-containing materials and residual materials.

[0062] (13) The remaining material from the magnetic separation was separated by a 6000 Gauss magnetic separator to separate the vanadium-containing steel slag and tailings.

[0063] (14) After mixing different batches of iron-containing materials evenly, samples were taken for testing. The content of metallic iron was 5.17% and the total iron content was 32.81%.

[0064] (15) After mixing different batches of vanadium-containing steel slag evenly, samples were taken for testing, and the V2O5 content was 4.76%.

[0065] In this embodiment, after crushing the granular portion and screening out the powder, the intermediate material is subjected to two magnetic separations. The first separation removes iron-containing materials, and the second separation removes vanadium-containing steel slag from the remaining material. The V2O5 content reaches 4.76%, which greatly improves the recovery rate of vanadium resources in steel slag materials and avoids the waste of vanadium resources.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dry method for preparing vanadium-containing steel slag, characterized in that, Includes the following steps: S1. Pre-dry the 0~60mm steel slag material in advance to control the moisture content to below 5%; S2. The dried steel slag material is screened off by the first screen, and the material on the screen is crushed by the high-pressure roller mill. After crushing, it is screened by the first screen, and the material on the screen is returned to the high-pressure roller mill for recycling. Specifically, the dried steel slag material is screened out using a 3-5mm first screen to remove the undersized material. The undersized material enters the feeding hopper, while the oversized material enters the feeding hopper. The material in the feeding hopper is conveyed to the elevator via the first conveyor belt, and then to the high-pressure roller mill hopper via the elevator. The high-pressure roller mill is used for crushing. By adjusting the transmission speed of the first conveyor belt, the material in the high-pressure roller mill hopper is kept at the same level until the crushing is completed. S3. After the materials that have passed through multiple screenings are mixed evenly using a stirring device, the powder material that passes through the screen is removed using a second screen. The granular material on the screen is then magnetically separated using a first magnetic separator to remove iron-containing materials and the remaining material. The remaining material is then magnetically separated again using a second magnetic separator to remove vanadium-containing steel slag and tailings. The second screen is a 0.5mm screen. The magnetic field strength of the first magnetic separator is 800 Gauss, and the magnetic field strength of the second magnetic separator is 6000 Gauss.

2. The method for obtaining vanadium-containing steel slag by dry process according to claim 1, characterized in that, The feeding hoppers include, in sequence, hopper #1, hopper #2, and hopper #3; after the material in hopper #1 is crushed, the material in hopper #2 is crushed, and after the material in hopper #2 is crushed, the material in hopper #3 is crushed.

3. The method for obtaining vanadium-containing steel slag by dry process according to claim 2, characterized in that, The feeding hoppers include, in sequence, hoppers #4, #5, #6, #7, #8, and #9. Undersized material is fed from hopper #4 to hopper #9 in sequence. After hopper #9 has finished feeding, the undersized material separated during the next round of crushing is fed from hopper #9 to hopper #4 in sequence.

4. The method for obtaining vanadium-containing steel slag by dry process according to claim 3, characterized in that, The undersized material is fed from silo #4 to silo #9 via a chute.

5. The method for dry preparation of vanadium-containing steel slag according to claim 4, characterized in that, The first screen is a 3mm screen.

6. The method for dry preparation of vanadium-containing steel slag according to claim 4, characterized in that, Step S3 includes: S31. Weigh the undersize material in silos 4, 5, 6, 7, 8 and 9 respectively, and calculate the weight ratio of the undersize material. S32. Set the feeding speed of materials from hoppers #4 to #9 to the second conveyor belt according to the ratio, and transport them to the mixing equipment through the second conveyor belt for uniform mixing; S33. Use a second screen of 0.5~1mm to screen out the granular material on the screen and the powder material under the screen; S34. The granular material on the screen is separated by a first magnetic separator with an 800~1000 Gauss, and the iron-containing material and the remaining material after magnetic separation are separated. S35. The remaining material after magnetic separation is subjected to a second magnetic separator with a strength of 5000~10000 Gauss to separate vanadium-containing steel slag and tailings.

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