CN109201354B - Magnetic hydrocyclone, combined magnetic-gravity separation system and combined magnetic-gravity separation method for weakly magnetic mineral concentration - Google Patents

Abstract

The invention discloses a magnetic hydrocyclone for weakly magnetic mineral concentration, which comprises a hydrocyclone, wherein a plurality of permanent magnets for forming magnetic field gradients are uniformly arranged on the outer wall of the hydrocyclone, and the direction of the magnetic field gradients is directed outwards from the inside of the hydrocyclone. The invention also provides a magnetic gravity combined sorting system and a method for carrying out magnetic gravity combined sorting by utilizing the magnetic gravity combined sorting system, comprising the following steps: s1: rough concentration is carried out on the weak magnetic minerals by using a strong magnetic separator or a high gradient magnetic separator to obtain rough concentrate; s2: and (3) conveying the rough concentrate obtained in the step (S1) into a magnetic hydrocyclone for separation to obtain settled sand and overflow, and collecting the settled sand to obtain a concentrate product. The method for combining magnetic and gravity separation fully utilizes the difference of specific magnetization coefficient and specific gravity between the weak magnetic mineral and gangue mineral, is used for the concentration of the weak magnetic mineral, and has the advantages of low energy consumption, high separation efficiency, low cost, easy adjustment and control and the like.

Description

Magnetic hydrocyclone and combined magnetic-gravimetric separation system for weakly magnetic mineral selection And magnetic gravity combined sorting method

Technical field

The invention belongs to the field of mineral processing, and in particular relates to a cyclone, a sorting system and a sorting method for weakly magnetic minerals.

Background technique

Weakly magnetic mineral resources mainly include hematite, limonite, siderite, ilmenite, wolframite, manganese ore and tantalum-niobium rare earth ore. These weakly magnetic mineral raw materials play an important role in my country's economic development. High gradient magnetic separation is a common method for processing weak magnetic minerals. However, due to the mechanical inclusion of gangue minerals, it is difficult to obtain qualified weak magnetic mineral concentrate products through a single high gradient magnetic separation operation. High gradient magnetic separation is usually used in production. Rough separation, the obtained coarse concentrate is then flotation selected to obtain the final concentrate product, the process is complex, the flotation reagent consumption is large, the production indicators are unstable, and pollution will occur. Compared with the magnetic flotation combined separation process, the magnetic gravity combined separation process has attracted increasing attention.

In recent years, high gradient magnetic separation has been used for rough separation of weakly magnetic minerals, and the obtained coarse concentrate is refined with a centrifuge to obtain better sorting indicators. However, in general, the recovery of fine-grained weakly magnetic minerals is The rate is still low. The development of new combined magnetic-gravimetric separation processes and equipment for weakly magnetic minerals is of great significance for the clean and efficient processing and utilization of weakly magnetic minerals.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the shortcomings and defects mentioned in the above background technology and provide a magnetic hydrocyclone, a combined magnetic and gravity separation system and a combined magnetic and gravity separation system for the selection of weakly magnetic minerals. Method: The magnetic hydrocyclone uses the magnetic field to strengthen the hydrocyclone's selection of weakly magnetic minerals, and the recovery rate of fine-grained weakly magnetic minerals is higher. In order to solve the above technical problems, the technical solutions proposed by the present invention are:

A magnetic hydrocyclone for the selection of weakly magnetic minerals, including a hydrocyclone. The outer wall of the hydrocyclone is evenly provided with a plurality of permanent magnets for forming a magnetic field gradient. The direction of the magnetic field gradient is given by The inside of the hydrocyclone points outward.

In the above magnetic hydrocyclone, preferably, the polarities of the permanent magnets on the side close to the outer wall of the hydrocyclone are alternately arranged, and the permanent magnets are all perpendicular to the outer wall of the hydrocyclone. The alternating polarity arrangement of the permanent magnets allows the N pole of one permanent magnet to move toward the S pole of the adjacent permanent magnet. The magnetic lines of force are densest near the hydrocyclone. The design of this structure can ensure that the magnetic field lines are densest at the outer wall of the hydrocyclone. The magnetic force is the largest and the effect is the best.

In the above magnetic hydrocyclone, preferably, the hydrocyclone includes a cylindrical section and a conical section connected to each other, the cylindrical section is located above the conical section, and an overflow pipe is provided above the cylindrical section. , the ore feeding port is provided above the side wall of the cylindrical section, and the sand sinking nozzle is provided at the bottom of the conical section.

In the above magnetic hydrocyclone, preferably, the inner diameter of the cylindrical section is in the range of 50-200mm, the length range is in the range of 50-150mm, the taper range of the conical section is in the range of 5-20°, and the inner diameter of the ore feeding port is The range is 10-40mm, the inner diameter range of the overflow pipe is 10-50mm, the depth range is 30-150mm, and the inner diameter range of the grit nozzle is 5-30mm.

In the above magnetic hydrocyclone, preferably, the magnitude of the magnetic field generated by the permanent magnet is 0.2-0.6T. The magnetic field strength can be selected according to the size of the hydrocyclone. The general magnetic field range is about 0.2-0.6T.

In a general hydrocyclone, the density of weakly magnetic minerals is usually greater than that of gangue minerals, so they will preferentially enter the underflow and become magnetic products. Gangue minerals enter the overflow and become non-magnetic products. However, the particle size of the minerals will also affect the The direction of minerals has a great influence. Small magnetic mineral particles are also subject to less centrifugal force, so they are easy to enter the overflow product and be lost, resulting in a decrease in recovery rate. The design principle of the magnetic hydrocyclone in the present invention is as follows: by evenly distributing strong permanent magnets with opposite polarities around the hydrocyclone, the direction of the magnetic field lines generated by the permanent magnets is from the N pole of one permanent magnet to the adjacent permanent magnet. The S pole of the magnet has the densest magnetic field lines near the hydrocyclone. The magnetic field gradient points from the inside of the hydrocyclone to the outside. Therefore, an outward magnetic field force is generated for the weakly magnetic mineral particles in it. In addition to centrifugal force, the magnetic minerals also It is subject to magnetic force from the inside to the outside, so it is more conducive to sand settling and becomes a magnetic product. The introduction of magnetism can greatly increase the recovery rate of fine-grained weakly magnetic minerals.

As a general technical concept, the present invention also provides a magnetic-gravimetric combined separation system, which includes a magnetic separator for roughly selecting weakly magnetic minerals and a magnetic hydrocyclone for selecting weakly magnetic minerals. .

As a general technical concept, the present invention also provides a method for magnetic-gravity combined sorting using the above-mentioned combined magnetic-gravity sorting system, which includes the following steps:

S1: Use a strong magnetic separator or a high gradient magnetic separator to roughly separate weakly magnetic minerals to obtain a coarse concentrate;

S2: Send the coarse concentrate obtained in S1 to a magnetic hydrocyclone for sorting to obtain sand settling and overflow, and collect the sand settling to obtain a concentrate product.

In the above method, preferably, the weakly magnetic mineral includes any one of hematite, limonite, siderite, manganese ore, wolframite and tantalum-niobium rare earth ore.

In the above method, preferably, the weakly magnetic minerals are crushed and slurried before rough selection. Crushing refers to pulverizing the weakly magnetic minerals to -200 mesh and accounting for 80-95%. Slurrying refers to crushing the pulverized minerals. The weakly magnetic minerals are adjusted to a slurry with a mass concentration of 25-35%.

In the above method, preferably, the rough selection is carried out under the conditions of 5000-10000GS.

In the above method, preferably, the coarse concentrate is adjusted to a slurry with a mass concentration of 30-45% and then sent to a magnetic hydrocyclone for sorting.

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

1. The magnetic hydrocyclone of the present invention is equipped with a permanent magnet on the outer wall of the hydrocyclone to form a centrifugal force-magnetic force field separation equipment. The strengthening effect of the magnetic field is used to obtain qualified concentrate products. Under this condition, the recovery rate of fine-grained weakly magnetic minerals can be improved as much as possible.

2. The magnetic-gravimetric combined sorting system and method of the present invention fully utilizes the difference in specific magnetization coefficient and specific gravity between weakly magnetic minerals and gangue minerals, and is used in the selection of weakly magnetic minerals. It has an environmentally friendly process and low energy consumption. , high sorting efficiency, low cost, easy to adjust and control, etc.

Description of the drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are: For some embodiments of the present invention, those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a magnetic hydrocyclone in Embodiment 1 of the present invention.

FIG. 2 is a top view of FIG. 1 .

Figure 3 is a process flow chart of the magnetic-gravity combined separation method of the present invention.

Figure 4 is a schematic structural diagram of the magnetic medium in the neutral ring high gradient magnetic separator in Embodiment 2.

Figure 5 is a schematic diagram of the rotating ring structure of the neutral ring high gradient magnetic separator in Example 2.

illustration:

1. Overflow pipe; 2. Permanent magnet; 3. Cylindrical section; 5. Conical section; 6. Sand settling nozzle; 7. Feeding port; 10. Non-magnetic part; 20. Magnetic part; 40. Swivel ring ; 50. Feeding system.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

Unless otherwise defined, all technical terms used below have the same meanings as commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of the present invention.

Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased in the market or prepared by existing methods.

Example 1:

As shown in Figures 1 and 2, the magnetic hydrocyclone used for the selection of weakly magnetic minerals in this embodiment includes a hydrocyclone. The outer wall of the hydrocyclone is evenly provided with a plurality of permanent magnets for forming a magnetic field gradient. Magnet 2, the direction of the magnetic field gradient points from the inside of the hydrocyclone to the outside.

In this embodiment, the polarities of the permanent magnets 2 are alternately arranged on the side close to the outer wall of the hydrocyclone, and the permanent magnets 2 are all perpendicular to the outer wall of the hydrocyclone. The highest magnetic field generated by permanent magnet 2 is 0.4T.

In this embodiment, the hydrocyclone includes a cylindrical section 3 and a conical section 5 connected to each other. The cylindrical section 3 is located above the conical section 5. An overflow pipe 1 is provided above the cylindrical section 3. The side wall of the cylindrical section 3 is above An ore feeding port 7 is provided, and a sand settling nozzle 6 is provided at the bottom of the cone section 5 . The outer walls of the cylindrical section 3 and the conical section 5 are both provided with permanent magnets 2 . Seven permanent magnets 2 are evenly distributed on the outer wall of the cylindrical section 3, and eight permanent magnets 2 are evenly distributed on the outer wall of the conical section 5.

In this embodiment, the inner diameter of the cylindrical section 3 is 150mm, the length is 150mm, the taper of the conical section 5 is 10°, the length of the conical section is 250mm, the inner diameter of the ore feeding port 7 is 20mm, and the inner diameter of the overflow pipe 1 is 30mm. , the depth is 30-150mm, and the inner diameter of the grit nozzle 6 is 20mm.

The combined magnetic and gravity separation system of this embodiment includes the above-mentioned magnetic hydrocyclone and a vertical ring pulsating high gradient magnetic separator.

As shown in Figure 3, the method of using the magnetic-gravitational combined separation system in this embodiment to carry out the combined magnetic-gravitational separation of hematite includes the following steps:

S1: Crush the weakly magnetic hematite with a grade of 25% to -200 mesh to account for 85%, and adjust the slurry to a mass concentration of 30% as feed material;

S2: Use a vertical ring pulsating high gradient magnetic separator to roughly select the above-mentioned ore under the conditions of 5000-10000GS to obtain a coarse concentrate with an iron grade of 45%, and slurry the coarse concentrate to 35%;

S3: Use a pump to send the sand into the magnetic hydrocyclone through the ore feeding port 7 for sorting to obtain the sand settling and overflow. The feeding pressure is 0.07MPa. Collect the sand settling to obtain the concentrate product, with an iron grade of 54%.

Example 2:

The magnetic hydrocyclone in this embodiment is the same as in Embodiment 1.

The magnetic-gravimetric combined separation system of this embodiment includes the above-mentioned magnetic hydrocyclone and a vertical ring high gradient magnetic separator.

The method of using the magnetic hydrocyclone in this embodiment to carry out magnetic gravity combined separation of hematite includes the following steps:

S1: Crush the weakly magnetic hematite with a grade of 25% to -200 mesh to account for 80%, and adjust the pulp to a mass concentration of 35% as feed material;

S2: Use a vertical ring high gradient magnetic separator to roughly separate the above-mentioned ore under the conditions of 5000-10000GS to obtain a coarse concentrate, and slurry the coarse concentrate to 45%;

S3: Use a pump to send the sand into the magnetic hydrocyclone through the ore feeding port 7 for sorting to obtain the sand settling and overflow. The feeding pressure is 0.07MPa. Collect the sand settling to obtain the concentrate product.

In this embodiment, the vertical ring high gradient magnetic separator (without a pulsation generator for applying pulsating flow) includes a rotating ring 40, a magnetic field generating device and a feeding system 50. The feeding system 50 is located inside the rotating ring 40. Magnetic media stacks are continuously and evenly arranged in the rotating ring 40 , and the magnetic media stacks are composed of multiple magnetic media. Among them, the magnetic medium is provided with a non-magnetic part 10 and a magnetic permeable part 20 in sequence along the slurry flow direction. The non-magnetic part 10 and the magnetic permeable part 20 are fixed to each other. The edge of the non-magnetic part 10 is a smooth curved surface for drainage. structure or sharp-angle structure (such as semicircle, semiellipse or semirhombus), the magnetic conductive part 20 is required to be able to generate a larger magnetic field range (such as semicircle, semiellipse or semirhombus), and more The capture of magnetic particles in the ore. As shown in Figure 4, the cross-sections of the non-magnetic permeable part 10 and the magnetic permeable part 20 of the magnetic medium shown in the figure are both semicircular (the shapes of the non-magnetic permeable part 10 and the magnetic permeable part 20 can also be changed according to needs. ). As shown in Figure 5, it is a schematic structural diagram of the rotating ring 40 of the neutral ring high gradient magnetic separator in this embodiment.

In the vertical ring high gradient magnetic separator of this embodiment, the non-magnetic permeable part 10 in the magnetic medium faces the center of the rotating ring 40 , and the magnetic permeable part 20 and the non-magnetic permeable part 10 in the magnetic media stack at the bottom of the rotating ring 40 are aligned The binding surface is perpendicular to the direction of the background magnetic field.

The vertical ring high gradient magnetic separator in this embodiment has the following advantages: 1. The magnetic medium of the vertical ring high gradient magnetic separator is sequentially provided with a non-magnetic part 10 and a magnetic permeable part 20 along the slurry flow direction, which can feed the ore. When magnetic particles and non-magnetic particles pass through the magnetic medium, the non-magnetic part 10 has no magnetic force and will not capture the magnetic particles. Moreover, due to the drainage effect of the non-magnetic part 10, basically all the ore feed passes through the non-magnetic part 10 without It will accumulate in the non-magnetic part 10, which can eliminate the accumulation of particles upstream of conventional magnetic media, eliminate the accumulation of magnetic particles upstream of the magnetic medium, make most or all of the magnetic particles accumulate downstream of the magnetic medium, and reduce the accumulation of magnetic minerals by the ore flow. Direct impact on the area, thereby reducing or eliminating mechanical inclusions and improving the grade of recovered minerals. 2. The non-magnetic permeable part 10 and the magnetic permeable part 20 of the magnetic medium of the vertical ring high gradient magnetic separator adopt specific shapes. By controlling the shapes of the non-magnetic permeable part 10 and the magnetic permeable part 20, they are closely related to the non-magnetic permeable part. 10 In combination with the material of the magnetic conductive part 20, the magnetic medium generates a flow field and magnetic field that is more conducive to the collection of magnetic minerals, which can further enhance the effect of the magnetic medium, reduce or eliminate mechanical inclusions, and at the same time strengthen weakly magnetic minerals. The collection efficiency. 3. The magnetic medium of the vertical ring high gradient magnetic separator can be directly applied to the existing conventional magnetic separator. It can be used directly without improving the structure of the current magnetic separator, making practical application more convenient.

Using the vertical ring high gradient magnetic separator in this embodiment to cooperate with the magnetic hydrocyclone, on the one hand, the coarse concentrate obtained by the vertical ring high gradient magnetic separator has less impurity content and higher grade; on the other hand, The existence of magnetic hydrocyclone can improve the recovery rate of fine-grained weakly magnetic minerals as much as possible on the premise of obtaining qualified concentrate products.

Claims (9)

1. A magnetic-gravity combined separation system, characterized in that it includes a magnetic separator for roughly selecting weakly magnetic minerals and a magnetic hydrocyclone for selecting weakly magnetic minerals, and the magnetic separator The machine is a vertical ring high gradient magnetic separator. The magnetic hydrocyclone includes a hydrocyclone. The outer wall of the hydrocyclone is evenly provided with a plurality of permanent magnets (2) for forming a magnetic field gradient. The magnetic field The direction of the gradient is from the inside of the hydrocyclone to the outside; The vertical ring high gradient magnetic separator includes a rotating ring (40), a magnetic field generating device and a feeding system (50). The feeding system 50 is located inside the rotating ring (40), and the rotating ring (40) continuously and uniformly A magnetic medium stack is provided, and the magnetic medium stack is composed of a plurality of magnetic media; wherein, the magnetic medium is provided with a non-magnetic part (10) and a magnetic permeable part (20) along the direction of the slurry flow, and the non-magnetic part (10) is ) and the magnetic conductive part (20) are fixedly connected to each other, and the edge of the non-magnetic conductive part (10) is a smooth curved surface structure or a sharp-angle structure for drainage; The cross-sections of the non-magnetic conductive part (10) and the magnetic conductive part (20) are both semicircular; The non-magnetic permeable part (10) in the magnetic medium faces the center of the rotating ring (40), and the joining surface of the magnetic permeable part (20) and the non-magnetic permeable part (10) in the stack of magnetic media at the bottom of the rotating ring (40) is perpendicular to in the direction of the background magnetic field. 2. The magnetic-gravity combined separation system according to claim 1, characterized in that the polarities of the permanent magnets (2) are alternately arranged on the side close to the outer wall of the hydrocyclone, and the permanent magnets (2) ) are perpendicular to the outer wall of the hydrocyclone. 3. The combined magnetic and gravity separation system according to claim 1, characterized in that the hydrocyclone includes a cylindrical section (3) and a conical section (5) connected to each other, and the cylindrical section (3) is located at An overflow pipe (1) is provided above the conical section (5) and above the cylindrical section (3), and a feed port (7) is provided above the side wall of the cylindrical section (3). The bottom of the cone section (5) is provided with a grit nozzle (6). 4. The magnetic-gravimetric combined sorting system according to claim 3, characterized in that the inner diameter range of the cylindrical section (3) is 50-200mm, the length range is 50-150mm, and the conical section (5) The taper range is 5-20°, the inner diameter range of the ore feeding port (7) is 10-40mm, the inner diameter range of the overflow pipe (1) is 10-50mm, and the depth range is 30-150mm. The inner diameter range of the sand nozzle (6) is 5-30mm. 5. The magnetic-gravity combined sorting system according to any one of claims 1-4, characterized in that the magnetic field generated by the permanent magnet (2) has a size of 0.2-0.6T. 6. A method for performing magnetic-gravity combined sorting using the combined magnetic-gravity sorting system according to any one of claims 1 to 5, characterized in that it includes the following steps: S1: Use a vertical ring high gradient magnetic separator to roughly separate weakly magnetic minerals to obtain a coarse concentrate; S2: Send the coarse concentrate obtained in S1 to a magnetic hydrocyclone for sorting to obtain sand settling and overflow, and collect the sand settling to obtain a concentrate product. 7. The method according to claim 6, wherein the weakly magnetic minerals include any one of hematite, limonite, siderite, manganese ore, wolframite and tantalum-niobium rare earth ore. 8. The method according to claim 6 or 7, characterized in that the weakly magnetic minerals undergo crushing and slurrying treatment before rough selection. Crushing refers to crushing the weakly magnetic minerals to -200 mesh and accounting for 80-95 %, slurry adjustment refers to adjusting the crushed weakly magnetic minerals to a slurry with a mass concentration of 25-35%. 9. The method according to claim 6 or 7, characterized in that the coarse concentrate is adjusted to a slurry with a mass concentration of 30-45% and then sent to a magnetic hydrocyclone for sorting.