Dry grinding and dry separation system and method for magnetic minerals

Abstract

The invention relates to the technical field of grinding, and particularly discloses a dry grinding and dry separation system and method for magnetic minerals. The dry grinding and dry separation system comprises a pre-crushing mechanism connected with the feeding system, a secondary grinding mechanism connected with a discharge port of the pre-crushing mechanism, a screening mechanism connected with a discharge port of the secondary grinding mechanism, a winnowing system connected with the screening mechanism, and a separation system communicated with a discharge port of the winnowing system; the dust collecting system and the dry magnetic separator are connected with the sorting system. According to the dry grinding and dry separation method, superfine powder and light ore can be effectively discarded, so that the treatment load of subsequent equipment is reduced, the influence of the fine powder on dry magnetic separation is reduced, the magnetic separation efficiency is improved, and the concentrate grade is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding, and more specifically, to a dry grinding and dry separation system and method for magnetic minerals. Background Art

[0002] In the prior art, in common dry grinding and dry separation systems for magnetic minerals such as iron ore, a high-pressure roller mill is used for final grinding, a screen machine + a dynamic classifier is used for classification, and dry magnetic separation is used for separation to finally obtain concentrate.

[0003] There are some defects in using the above treatment methods, that is:

[0004] 1. The process of the final grinding system is relatively long. The raw materials generally have a large particle size, while the returned materials have a small particle size and contain a certain amount of fine powder. When the two are mixed and enter the high-pressure roller mill, due to the large particle size difference, a dense cake cannot be formed, which affects the extrusion effect of the high-pressure roller mill, resulting in problems such as a large circulation volume and unstable operation in this section of the system.

[0005] 2. Among the materials entering the dry magnetic separator, there are a considerable amount of light minerals, ultrafine powder, etc., which affect the magnetic separation effect and reduce the concentrate grade. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a dry grinding and dry separation system and method for magnetic minerals. The present invention can effectively discard waste of ultrafine powder and light minerals, thereby reducing the processing load of subsequent equipment, reducing the influence of fine powder on dry magnetic separation, improving the magnetic separation efficiency, and improving the concentrate grade;

[0007] The solution adopted by the present invention to solve the technical problem is:

[0008] A dry grinding and dry separation system for magnetic minerals includes a pre-crushing mechanism connected to a feeding system, a secondary grinding mechanism connected to the discharge port of the pre-crushing mechanism, a screening mechanism connected to the discharge port of the secondary grinding mechanism, a pneumatic separation system connected to the screening mechanism, a separation system communicated with the discharge port of the pneumatic separation system, and a dust collection system and a dry magnetic separator connected to the separation system.

[0009] In some possible implementation manners, the pre-crushing mechanism includes a roller grinding device connected to the outlet end of the feeding system and an intermediate ore bin communicated with the discharge port of the roller grinding device.

[0010] In some possible implementation manners, the screening mechanism is provided with a screen oversize outlet, a screen undersize outlet, and a feed inlet; the screen oversize outlet is communicated with the secondary grinding mechanism through a pipeline one; the feed inlet is connected to the discharge port of the secondary grinding mechanism; the screen undersize outlet is connected to the feed inlet of the pneumatic separation system.

[0011] In some possible embodiments, the air separation system includes a first dynamic classifier connected to the outlet of the screened material, a dust collection device connected to the air outlet of the first dynamic classifier, and a fan connected to the dust collection device; the outer discharge port of the first dynamic classifier is connected to the secondary grinding mechanism.

[0012] In some possible embodiments, the sorting system includes a conveying device communicating with the discharge port of the dust collection device and conveying the material processed by the dust collection device, and a powder selection device used in cooperation with the conveying device; the powder selection device is respectively connected to the dust collection system and the dry magnetic separator.

[0013] In some possible embodiments, both the roller grinding device and the secondary grinding mechanism are high-pressure roller mills.

[0014] In some possible embodiments, the dust collection device and the dust collection system are respectively a bag filter, a cyclone separator or a pulse dust collector.

[0015] In some possible embodiments, the powder selection device is a dynamic classifier.

[0016] A dry grinding and dry separation method for magnetic minerals, based on the above-mentioned dry grinding and dry separation system for magnetic minerals, is characterized in that it specifically includes the following steps:

[0017] Step S1: After the raw ore material is metered and de-ironed by the feeding system, it enters the pre-crushing mechanism for pre-crushing treatment to obtain the metered material A;

[0018] Step S2: The material A enters the secondary grinding mechanism for final grinding, forms a cake after high-pressure extrusion, and enters the screening mechanism for particle size classification and screening; the coarse particles on the screen return to the secondary grinding mechanism through the oversize outlet for cyclic extrusion; the fine particles under the screen enter the air separation system through the undersize outlet.

[0019] Step S3: After the fine particles under the screen are dispersed, sorted and gas-solid separated by the air separation system, material B and coarse particles are obtained, and the coarse particles enter the secondary grinding mechanism for treatment;

[0020] Step S4: Material B enters the sorting system for further treatment to obtain ultra-fine powder, light minerals and material C. Among them, the ultra-fine powder and light minerals are treated by the dust collection system and used as tailings A; material C enters the dry magnetic separator for magnetic separation to obtain concentrate and tailings B, and the concentrate, tailings A and tailings B are respectively sent to the corresponding ore bins for stacking.

[0021] In some possible embodiments, in step S4, material B enters the sorting system for further processing to obtain ultrafine powder, light minerals, and material C; specifically, a dynamic classifier is used to separate material B; the separated light minerals and ultrafine powder are discarded, and the remaining material after removing the light minerals and ultrafine powder is fed into a dry magnetic separator as material C for magnetic separation to obtain concentrate and tailing B.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The present invention adds a pre-crushing mechanism compared with the prior art to achieve crushing of the raw ore material; the particle size of the crushed material becomes smaller and more uniform, and it is filled with micro-cracks inside, which is more conducive to subsequent grinding. Through the cooperation of the secondary grinding mechanism, the subsequent recycled material enters the secondary grinding mechanism and is mixed with the material crushed by the pre-crushing mechanism, with a small particle size difference, thereby forming a dense cake and reducing the circulation volume.

[0024] The present invention sets up a classification device to reclassify the material after air separation by the air separation system, and discard the separated ultrafine powder and light minerals, which can reduce the processing load of subsequent equipment, reduce the influence of fine powder on dry magnetic separation, improve the magnetic separation efficiency, and improve the concentrate grade. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the present invention;

[0026] Wherein: 1. Pre-crushing mechanism; 11. Roller mill device; 12. Transfer ore bin; 2. Secondary grinding mechanism; 3. Screening mechanism; 4. Air separation system; 41. Dynamic classifier I; 42. Dust collection system; 43. Fan; 5. Sorting system; 51. Conveying equipment; 52. Classification equipment; 6. Dust collection device; 60. Air release fan; 7. Dry magnetic separator. SPECIFIC EMBODIMENTS

[0027] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "attachment", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. The "first", "second" and similar terms mentioned in this application do not represent any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "one" or "a" do not represent a quantity limit either, but indicate that there is at least one. In the implementation of this application, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In the description of the embodiments of this application, unless otherwise stated, the meaning of "a plurality of" refers to two or more. For example, a plurality of positioning posts refers to two or more positioning posts. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The present invention will be described in detail below.

[0029] As Figure 1 shown:

[0030] A dry grinding and dry separation system for magnetic minerals, comprising a pre-crushing mechanism 1 connected to a feeding system, a secondary grinding mechanism 2 connected to the discharge port of the pre-crushing mechanism 1, a screening mechanism 3 connected to the discharge port of the secondary grinding mechanism 2, a pneumatic separation system 4 connected to the screening mechanism 3, a separation system 5 communicated with the discharge port of the pneumatic separation system 4, and a dust collection system 6 and a dry magnetic separator 7 connected to the separation system 5;

[0031] During use, the raw ore is metered, weighed, and de-ironed by the feeding system, and then fed into the pre-powdering mechanism. After being crushed by the pre-crushing mechanism 1, material A with a smaller particle size and micro-cracks inside is obtained, which is more conducive to subsequent grinding;

[0032] The material A crushed by the pre-crushing mechanism 1 is metered and sent to the secondary grinding mechanism 2 for final grinding;

[0033] In the final grinding stage, the material A is formed into a cake after high-pressure extrusion and then conveyed into the screening mechanism 3;

[0034] The screening mechanism 3 vibrates and disperses the crushed material A again for particle size classification screening, obtaining coarse-grained materials on the screen and fine-grained materials under the screen; among them, the coarse-grained materials on the screen are returned to the secondary grinding mechanism 2 for cyclic extrusion; the fine-grained materials under the screen are fed into the subsequent pneumatic separation system 4;

[0035] The fine particulate materials screened out are processed by the air separation system 4 to separate out coarse particulate materials and fine particulate materials; specifically, the coarse particulate materials enter the secondary grinding mechanism 2 for cyclic extrusion treatment again, and the fine particulate materials in the air separation system 4, after waiting for material and gas separation, obtain material B, and material B is sent into the sorting system 5;

[0036] Material B is processed again in the sorting system 5 to obtain ultrafine powder, light minerals and material C. Among them, the ultrafine powder and light minerals are processed by the dust collection system 6 and used as tailings A; material C enters the dry magnetic separator 7 for magnetic separation to obtain concentrate and tailings B, and tailings A, concentrate and tailings B are respectively sent to the corresponding ore bins for stacking.

[0037] The present invention realizes two-stage grinding through the pre-crushing mechanism 1 and the secondary grinding mechanism 2; the materials crushed by the pre-crushing mechanism 1 are mixed with the subsequent returned materials in the secondary grinding mechanism 2, and the particle size difference of the mixed materials is small, so that the density of the formed cake is high, the circulation amount is reduced, and the operation of the whole system is more stable; by setting the sorting system 5 to realize reverse enrichment and carry out waste throwing treatment on light minerals and ultrafine powder, the processing load of subsequent equipment can be reduced, the influence of ultrafine powder and light minerals on dry magnetic separation can be reduced, the magnetic separation efficiency can be improved, and the concentrate grade can be improved.

[0038] In some possible implementation manners, in order to effectively realize the crushing and metering of the iron-removed raw ore materials by the pre-crushing mechanism 1, so that the crushed material A is beneficial to subsequent grinding; the pre-crushing mechanism 1 includes a roller grinding device 11 connected to the outlet end of the feeding system and used for crushing the raw ore materials, and a transfer ore bin 12 communicated with the outlet of the roller grinding device 11; the crushed material A enters the transfer ore bin 12, after being metered, enters the secondary grinding mechanism 2 for secondary grinding.

[0039] In some possible implementation manners, a screen upper material outlet, a screen lower material outlet and a feed inlet are arranged on the screening mechanism 3; the screen upper material outlet is communicated with the secondary grinding mechanism 2 through a first pipeline; the feed inlet is connected to the outlet of the secondary grinding mechanism 2; the screen lower material outlet is connected to the feed inlet of the air separation system 4.

[0040] Specifically, a screen is arranged in the screening mechanism 3, and the screen divides the inside of the screening mechanism 3 into bin A with a screen upper material outlet and bin B with a screen lower material outlet; the screen upper coarse particulate matters in bin A after screening by the screening mechanism 3 are sent into the secondary grinding mechanism 2 through the first pipeline for grinding treatment; the screen lower fine particulate materials in bin B are fed into the air separation system 4.

[0041] In some possible embodiments, the air separation system 4 includes a first dynamic powder separator 41 connected to the sieve discharge outlet, a dust collection device 42 connected to the air outlet of the first dynamic powder separator 41, and a blower 43 connected to the dust collection device 42; the external discharge port of the first dynamic powder separator 41 is connected to the secondary grinding mechanism 2.

[0042] Specifically, the blower 43 provides powder separation power support for the first dynamic powder separator 41 and the dust collection device 42.

[0043] The fine particulate matter under the sieve enters the first dynamic powder separator 41 and is dispersed and separated by wind force inside it; among them, the separated coarse-grained materials are discharged from the external discharge port at the lower part of the first dynamic powder separator 41 and returned to the secondary grinding mechanism 2 for cyclic extrusion.

[0044] The separated fine-grained materials are carried by the air flow from the air outlet of the first dynamic powder separator 41 into the dust collection device 42. After realizing material-gas separation in the dust collection device 42, material B is obtained, and material B is discharged from the discharge port of the dust collection device 42 and enters the separation system 5; the gas purified by the dust collection device 42 is discharged into the atmosphere by the blower 43.

[0045] In some possible embodiments, the separation system 5 includes a conveying device 51 communicating with the discharge port of the dust collection device 42 and used for conveying the material B processed by the dust collection device 42, and a powder separation device 52 used in cooperation with the conveying device 51; the powder separation device 52 is respectively connected to the dust collection system 6 and the dry magnetic separator 7.

[0046] The material B discharged from the discharge port of the dust collection device 42 is sent to the powder separation device 52 by the conveying device 51 for separation, and ultra-fine powder, light minerals, and material C are separated; among them:

[0047] The separated ultra-fine powder and light minerals are carried by the air flow from the air outlet of the powder separation device 52 into the dust collection system 6. After realizing material-gas separation in the dust collection system 6, they are discharged from the discharge port of the dust collection system 6 and used as tailings A; the gas purified by the dust collection system 6 is discharged into the atmosphere by the air release blower 60 connected to the dust collection system 6.

[0048] The material C separated by the powder separation device 52 is discharged from the discharge port of the powder separation device 52 and fed into the dry magnetic separator 7 for magnetic separation. The discharge of the dry magnetic separator 7 is divided into two types: concentrate and tailings B, which are respectively sent to the corresponding ore bins for stacking.

[0049] In some possible embodiments, both the roller grinding device 11 and the secondary grinding mechanism 2 are high-pressure roller mills in the prior art.

[0050] In some possible embodiments, the dust collection device 42 and the dust collection system 6 are respectively bag dust collectors, cyclone separators or pulse dust collectors in the prior art.

[0051] In some possible embodiments, the powder selection device 52 is a dynamic powder separator in the prior art.

[0052] Furthermore, both the feeding system 1 and the conveying device 51 include belt conveyors; wherein, a metal detector and a de-ironing device are provided on the belt conveyor of the feeding system 1, so as to realize the conveying and de-ironing of the material A.

[0053] A dry grinding and dry separation method for magnetic minerals, based on the above-mentioned dry grinding and dry separation system for magnetic minerals, specifically includes the following steps:

[0054] Step S1: After the raw ore material is metered and de-ironed by the feeding system, it enters the pre-crushing mechanism 1 for pre-crushing treatment to obtain the metered material A;

[0055] Step S2: The material A enters the secondary grinding mechanism 2 for final grinding, forms a cake after high-pressure extrusion, enters the screening mechanism 3 for screening treatment and particle size classification screening through the sieve in the screening mechanism 3; the coarse particles on the sieve return to the secondary grinding mechanism 2 for cyclic extrusion through the oversize outlet; the fine particles under the sieve enter the air separation system 4 through the undersize outlet;

[0056] Step S3: After being dispersed, separated and gas-solid separated by the air separation system 4, the fine particles under the sieve obtain the material B and coarse particles. The coarse particles enter the secondary grinding mechanism 2 for cyclic extrusion, and the material B enters the separation system 5;

[0057] Step S4: The material B entering the separation system 5 is processed again to obtain ultrafine powder, light minerals and material C, wherein:

[0058] The ultrafine powder and light minerals are treated by the dust collection system 6 and used as tailings A;

[0059] The material C enters the dry magnetic separator 7 for magnetic separation to obtain concentrate and tailings B, and the tailings A, concentrate and tailings B are respectively sent to the corresponding ore bins for storage.

[0060] In some possible embodiments, the material B entering the separation system 5 in step S4 is processed again to obtain ultrafine powder, light minerals and material C; specifically, it means that a dynamic powder separator is used to separate the material B, wherein the light minerals and ultrafine powder are separated and discarded, and the remaining material after removing the light minerals and ultrafine powder is used as the material C and fed into the dry magnetic separator 7 for magnetic separation in the dry magnetic separator 7.

[0061] The present invention is not limited to the foregoing specific embodiments. The present invention extends to any new feature or any new combination disclosed in this specification, as well as any new combination of the steps of any new method or process disclosed.

Claims

1. A dry grinding and dry separation system for magnetic minerals, characterized in that, It includes a pre-crushing mechanism connected to a feeding system, a secondary grinding mechanism connected to the discharge port of the pre-crushing mechanism, a screening mechanism connected to the discharge port of the secondary grinding mechanism, a pneumatic separation system connected to the screening mechanism, a sorting system communicated with the discharge port of the pneumatic separation system, and a dust collection system and a dry magnetic separator connected to the sorting system.

2. The dry grinding and dry separation system for a magnetic mineral according to claim 1, characterized in that The pre-crushing mechanism includes a roller mill device connected to the outlet end of the feeding system and an intermediate ore bin communicated with the discharge port of the roller mill device.

3. The dry grinding and dry separation system for a magnetic mineral according to claim 1, characterized in that, The screening mechanism is provided with an oversize material outlet, an undersize material outlet and a feed inlet; the oversize material outlet is communicated with the secondary grinding mechanism through a first pipeline; the feed inlet is connected to the discharge port of the secondary grinding mechanism; the undersize material outlet is connected to the feed inlet of the pneumatic separation system.

4. A dry grinding and dry separation system for magnetic minerals according to claim 1, characterized in that, The pneumatic separation system includes a dynamic classifier I connected to the undersize material outlet, a dust collection device connected to the air outlet of the dynamic classifier I, and a fan connected to the dust collection device; the outer discharge port of the dynamic classifier I is connected to the secondary grinding mechanism.

5. The dry grinding and dry separation system for a magnetic mineral according to claim 1, wherein The sorting system includes a conveying device communicated with the discharge port of the dust collection device and used for conveying the material processed by the dust collection device, and a sizing device used in cooperation with the conveying device; the sizing device is respectively connected to the dust collection system and the dry magnetic separator.

6. A dry grinding and dry separation system for magnetic minerals according to claim 2, characterized in that, Both the roller mill device and the secondary grinding mechanism are high-pressure roller mills.

7. A dry grinding and dry separation system for magnetic minerals according to claim 4, characterized in that, The dust collection device and the dust collection system are respectively a bag filter, a cyclone separator or a pulse dust collector.

8. A dry grinding and dry separation system for magnetic minerals according to claim 5, characterized in that, The sizing device is a dynamic classifier.

9. A dry grinding and dry separation method for magnetic minerals, based on the dry grinding and dry separation system for magnetic minerals according to any one of claims 1-8, characterized in that, Specifically, it includes the following steps: Step S1: The raw ore material is metered and de-ironed by the feeding system and then enters the pre-crushing mechanism for pre-crushing treatment to obtain the metered material A. Step S2: The material A enters the secondary grinding mechanism for final grinding, forms a cake after high-pressure extrusion, and enters the screening mechanism for particle size classification and screening; the oversize coarse-grained material returns to the secondary grinding mechanism through the oversize material outlet for cyclic extrusion; the undersize fine-grained material enters the pneumatic separation system through the undersize material outlet. Step S3: The undersize fine-grained material is dispersed, sorted and gas-solid separated by the pneumatic separation system to obtain material B and coarse-grained material, and the coarse-grained material enters the secondary grinding mechanism for treatment. Step S4: The material B enters the sorting system for further treatment to obtain ultra-fine powder, light minerals and material C. Among them, the ultra-fine powder and light minerals are treated by the dust collection system and used as tailings A; the material C enters the dry magnetic separator for magnetic separation to obtain concentrate and tailings B, and the tailings A, concentrate and tailings B are respectively sent to the corresponding ore bins for storage.

10. A dry grinding and dry separation method for magnetic minerals according to claim 9, characterized in that In step S4, the material B enters the sorting system for further treatment to obtain ultra-fine powder, light minerals and material C; specifically, it means that a dynamic classifier is used to separate the light minerals from the material B, select the ultra-fine powder and perform waste rejection treatment, and then the remaining material after removing the light minerals and ultra-fine powder is used as material C and fed into the dry magnetic separator.

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