Efficient grinding process for viscous magnetite

Abstract

The invention discloses an efficient grinding process for viscous magnetite, and belongs to the technical field of mineral separation. According to the method, the processes of two-section closed-circuit crushing, pre-ore washing and grading, dry-type pre-selection and tailing discarding, high-pressure roller mill series connection ultrafine crushing, wet-type tailing discarding and tower grinding are adopted, coarse-crushed viscous magnetite is subjected to ore washing and grading through an ore washing sieve, and fine-fraction minerals can be prevented from being bonded and blocking a crusher and a screen. Secondly, through the processes of ultrafine crushing of a high-pressure roller mill, tower milling, lump ore pre-selection, wet type tailing discarding and the like, multi-throwing and multi-crushing are realized before grinding, the material grinding granularity is effectively reduced, the grinding grade is improved, the treatment capacity of the next procedure is reduced, meanwhile, the ore grinding amount of an ore grinding machine is reduced, and the concepts of multi-crushing and less grinding and'throwing and early throwing 'are fully played; the problem of non-uniform distribution of grinding particle sizes is solved, the ore grinding efficiency can be better improved, mineral over-grinding is reduced, the separation efficiency is improved, and the energy consumption of ore grinding operation can also be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, in particular to a high-efficiency crushing and grinding process for viscous magnetite. Background Art

[0002] The conventional crushing and grinding process currently in common use often has problems such as clogging crushers, vibrating screens and other equipment and feed ports, low production efficiency, and uneven distribution of mill particle sizes when processing sticky magnetite. Sticky magnetite contains fine particles and easily sticky materials. During the crushing process, it is easy to clog the crusher and screen, causing serious equipment wear, resulting in high energy consumption of the crushing system, unstable equipment operation, and low crushing efficiency. At the same time, in order to facilitate the passage of materials, the discharge port and screen holes are large, which easily leads to coarse crushing particles. The product particle size of the sticky magnetite after crushing is coarse and unevenly distributed, resulting in poor grinding effect of equipment such as ball mills for sticky magnetite, high energy consumption, and unfavorable subsequent separation operations, affecting the quality and recovery rate of concentrate products. Summary of the invention

[0003] The purpose of the present invention is to provide a high-efficiency crushing and grinding process for sticky magnetite, which can better improve the grinding efficiency, reduce mineral over-grinding, improve the sorting efficiency, and reduce the energy consumption of the grinding operation to solve the problems raised by the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A high-efficiency crushing and grinding process for sticky magnetite comprises the following steps:

[0006] S1: Coarse crushing of incoming ore from the mine;

[0007] S2: The coarsely crushed product is pre-washed and graded through a double-layer ore washing screen to obtain products of three particle sizes: +30mm, -30+5mm, and -5mm;

[0008] S3: +30mm particle size products are crushed after iron removal, and the crushed products are returned to the pre-washing and classification;

[0009] S4: -30+5mm particle size products are subjected to dry magnetic separation to obtain pre-selected concentrate and tailings;

[0010] S5: the pre-selected concentrate in S4 is put into high pressure roller mill for roller pressing;

[0011] S6: The product after the high pressure roller mill is screened, the +8mm particle size product is returned to the high pressure roller mill, and the -8mm particle size product is combined with the -5mm particle size product in S2 for coarse powder wet pre-selection;

[0012] S7: Screening the wet pre-selected tailings to obtain three products: -8 to +2 mm gravel, -2 to 0.1 mm coarse sand, and -0.1 to 0 mm fine tailings;

[0013] S8: Screening the wet pre-selected concentrate, and the products with a particle size of +1 mm on the screen undergo secondary high-pressure roller grinding, and the products after roller grinding continue to be screened;

[0014] S9: The -1mm particle size product under the sieve in S8 is subjected to wet tailings discarding by a high-efficiency magnetic separator to obtain concentrate and tailings;

[0015] S10: The concentrate from the high-efficiency magnetic separator in S9 is classified by a cyclone to obtain sand settling and overflow, and the overflow enters the separation operation;

[0016] S11: The sand in S10 enters the tower mill for grinding, and the discharged ore products from the tower mill return to S10 for cyclone classification;

[0017] S12: The high-efficiency magnetic separation tailings in S9 are put into graded sand dredging operation to obtain fine sand of -1 to 0.1 mm and fine tailings of -0.1 to 0.1 mm.

[0018] Furthermore, the block tail products of S4 are reused as building materials.

[0019] Furthermore, the gravel and coarse sand obtained in S7 are used as building materials, and the fine tailings are used for filling or discharged into the tailings pond.

[0020] Furthermore, the fine sand obtained in S12 is used as a comprehensive utilization product, and the fine tailings are used to fill or discharge the tailings pond.

[0021] Furthermore, the wet pre-selection in S6 adopts a medium-to-high field strength and high-particle wet magnetic separator, and a demagnetizer is provided on the concentrate pipeline of the wet magnetic separator to demagnetize the concentrate product after magnetic separation.

[0022] Furthermore, the equipment used in the high pressure roller milling process in S5 is a double-roll high pressure roller mill.

[0023] Furthermore, in S1, the ore from the mine is crushed in an open circuit using a coarse crusher, and the coarse crushed product is sent to S2 for ore washing and screening.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The high-efficiency crushing and grinding process of sticky magnetite of the present invention adopts a two-stage one-closed-circuit crushing - pre-washing and grading - dry pre-selection and tailings discarding - high-pressure roller mill in series ultra-fine crushing - wet tailings discarding - tower grinding process, so that the sticky magnetite after coarse crushing is washed and graded by a washing screen, which can prevent the fine-grained minerals from sticking together and clogging the crusher and the screen.

[0026] 2. The high-efficiency crushing and grinding process of sticky magnetite of the present invention realizes more throwing and more crushing before entering the mill through processes such as ultra-fine crushing by high-pressure roller mill, tower mill, lump ore pre-selection, and wet tailings discarding, thereby effectively reducing the particle size of the material entering the mill, improving the grade of the material entering the mill, reducing the processing volume of the next step, and at the same time reducing the grinding volume of the grinding machine, reducing the operating energy consumption, giving full play to the concepts of "more crushing and less grinding" and "early discarding when possible" to achieve high-efficiency crushing and grinding of sticky magnetite. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 In the embodiment of the present invention, a high-efficiency crushing and grinding process for sticky magnetite is provided, which mainly prevents fine-grained minerals from clogging the crusher and the screen by pre-washing and grading, and also prevents the crushed product from being too coarse; through high-pressure roller grinding and dry and wet tailings throwing processes, "more crushing and less grinding" and "early throwing when possible" are achieved, and at the same time, the particle size of the material entering the mill is effectively reduced, and the problem of uneven distribution of the particle size entering the mill is solved. The specific process steps are as follows:

[0030] S1: Coarsely crush the incoming ore from the mine; specifically, a jaw crusher is used for one-time open-circuit crushing, and the coarsely crushed product enters S2 for ore washing and screening.

[0031] S2: The coarsely crushed product is pre-washed and graded through a double-layer ore washing screen to obtain products of three particle sizes: +30mm, -30+5mm, and -5mm;

[0032] S3: +30mm particle size products are crushed after iron removal, and the crushed products are returned to the pre-washing and classification;

[0033] S4: -30+5mm particle size products are subjected to dry magnetic separation to obtain pre-selected concentrate and tailings, which are then reused as building materials;

[0034] S5: the pre-selected concentrate in S4 is put into a high pressure roller mill for roller pressing; the high pressure roller mill is a double-roller high pressure roller mill;

[0035] S6: The products after high pressure roller mill are screened, the +8mm particle size products are returned to the high pressure roller mill, and the -8mm particle size products are combined with the -5mm particle size products in S2 for coarse powder wet pre-selection; wherein, the wet pre-selection adopts a medium-high field strength particle wet magnetic separator, and a demagnetizer is set on the concentrate pipeline of the wet magnetic separator to demagnetize the concentrate product after magnetic separation;

[0036] S7: Screening the wet pre-selected tailings to obtain three products: -8 to +2 mm gravel, -2 to 0.1 mm coarse sand, and -0.1 to 0 mm fine tailings; the gravel and coarse sand obtained are used as building materials, and the fine tailings are used for filling or discharged into the tailings pond;

[0037] S8: Screening the wet pre-selected concentrate, and the products with a particle size of +1 mm on the screen undergo secondary high-pressure roller grinding, and the products after roller grinding continue to be screened;

[0038] S9: The -1mm particle size product under the sieve in S8 is subjected to wet tailings discarding by a high-efficiency magnetic separator to obtain concentrate and tailings;

[0039] S10: The concentrate from the high-efficiency magnetic separator in S9 is classified by a cyclone to obtain sand settling and overflow, and the overflow enters the separation operation;

[0040] S11: The sand in S10 enters the tower mill for grinding, and the discharged ore products from the tower mill return to S10 for cyclone classification;

[0041] S12: The high-efficiency magnetically separated tailings in S9 are subjected to graded sand dredging operations to obtain fine sand of -1 to 0.1 mm and fine tailings of -0.1 to 0.1 mm; the obtained fine sand is used as a comprehensive utilization product, and the fine tailings are used to fill or stack the tailings pond.

[0042] In summary: The present invention provides a high-efficiency crushing and grinding process for sticky magnetite, which adopts a two-stage one-closed-circuit crushing-pre-washing and grading-dry pre-selection and tailings discarding-high-pressure roller mill in series ultra-fine crushing-wet tailings discarding-tower grinding process. The sticky magnetite after coarse crushing is washed and graded by a washing screen, which can prevent the fine-grained minerals from sticking together and clogging the crusher and the screen. Secondly, through the processes of high-pressure roller mill ultra-fine crushing, tower grinding, lump ore pre-selection, wet tailings discarding, etc., more throwing and more crushing can be achieved before entering the mill, effectively reducing the particle size of the material entering the mill, improving the grade of the material entering the mill, reducing the processing volume of the next step, and at the same time reducing the grinding volume of the mill, reducing the operating energy consumption, giving full play to the concept of "more crushing and less grinding" and "early throwing when possible", and realizing efficient crushing and grinding of sticky magnetite.

[0043] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A high-efficiency grinding process for sticky magnetite, characterized in that: The following steps are involved: S1: Coarse crushing of incoming ore from the mine; S2: The coarsely crushed product is pre-washed and graded through a double-layer ore washing screen to obtain products of three particle sizes: +30mm, -30+5mm, and -5mm; S3: +30mm particle size products are crushed after iron removal, and the crushed products are returned to the pre-washing and classification; S4: -30+5mm particle size products are subjected to dry magnetic separation to obtain pre-selected concentrate and tailings; S5: the pre-selected concentrate in S4 is put into high pressure roller mill for roller pressing; S6: The product after the high pressure roller mill is screened, the +8mm particle size product is returned to the high pressure roller mill, and the -8mm particle size product is combined with the -5mm particle size product in S2 for coarse powder wet pre-selection; S7: Screening the wet pre-selected tailings to obtain three products: -8 to +2 mm gravel, -2 to +0.1 mm coarse sand, and -0.1 to 0 mm fine tailings; S8: Screening the wet pre-selected concentrate, and the products with a particle size of +1 mm on the screen undergo secondary high-pressure roller grinding, and the products after roller grinding continue to be screened; S9: The -1mm particle size product under the sieve in S8 is subjected to wet tailings discarding by a high-efficiency magnetic separator to obtain concentrate and tailings; S10: The concentrate from the high-efficiency magnetic separator in S9 is classified by a cyclone to obtain sand settling and overflow, and the overflow enters the separation operation; S11: The sand in S10 enters the tower mill for grinding, and the discharged ore products from the tower mill return to S10 for cyclone classification; S12: The high-efficiency magnetic separation tailings in S9 are put into graded sand dredging operation to obtain fine sand of -1 to 0.1 mm and fine tailings of -0.1 to 0.1 mm.

2. The high-efficiency grinding process for sticky magnetite according to claim 1, characterized in that: The tailings of S4 blocks are reused as building materials.

3. The high-efficiency grinding process for sticky magnetite according to claim 1, characterized in that: The gravel and coarse sand obtained in S7 are used as building materials, and the fine tailings are used for filling or discharged into the tailings pond.

4. The high-efficiency grinding process for sticky magnetite according to claim 1, characterized in that: The fine sand obtained in S12 is used as a comprehensive utilization product, and the fine tailings are used to fill or discharge the tailings pond.

5. The high-efficiency grinding process for sticky magnetite according to claim 1, characterized in that: The wet pre-selection in S6 adopts a medium-to-high field strength and high-particle wet magnetic separator. A demagnetizer is installed on the concentrate pipeline of the wet magnetic separator to demagnetize the concentrate product after magnetic separation.

6. The high-efficiency grinding process for sticky magnetite according to claim 1, characterized in that: The equipment used in the high pressure roller grinding process in S5 is a double-roll high pressure roller grinding machine.

7. The high-efficiency grinding process for sticky magnetite according to claim 1, characterized in that: In S1, the ore from the mine is crushed in an open circuit using a coarse crusher, and the coarse crushed products are sent to S2 for ore washing and screening.

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