Method for weakening magnetic agglomeration before magnetite separation

Abstract

The invention relates to the technical field of magnetite separation, in particular to a method for weakening magnetic agglomeration before magnetite separation, which comprises the following steps of: connecting an air supply pipeline to a pulp supply pipeline behind a demagnetizer, and blowing air input into the air supply pipeline to enable pulp to form turbulent flow; according to the method, magnetic agglomeration of mineral particles in ore pulp is blown away through wind power blowing, residual magnetism, generated by previous magnetic separation, of magnetic materials in the ore pulp is weakened through mutual collision, the wind pressure P of wind power blowing is 0.30-2 MPa, and the pipeline caliber air volume Q is 0.5-10 m < 3 > / min. The method has the beneficial effects that the magnetic agglomeration phenomenon is weakened; magnetic inclusions in the ore pulp are destroyed or eliminated; and the grade of later-stage sorted concentrate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of magnetite beneficiation, in particular to a method for weakening magnetic agglomeration of magnetite before separation. Background Art

[0002] Magnetic separation utilizes the magnetic differences between useful minerals and gangue minerals for separation. It boasts a simple process and excellent separation results. However, the separation process typically does not complete the separation in a single stage. During the initial magnetic separation process, magnetic minerals in the slurry retain a certain degree of magnetism, forming magnetic chains that aggregate with the gangue minerals, affecting subsequent separation results. In typical separation processes, the slurry passes through a demagnetizer after each separation stage to eliminate residual magnetism. However, this cannot completely eliminate magnetic agglomeration, which can affect subsequent separation results.

[0003] The Chinese utility model patent with patent announcement number CN217016968U, "A high-intensity magnetic separator equipped with ultrasonic waves", provides a method of combining magnetic media and ultrasonic transducers, using the vibration and cavitation generated by ultrasonic waves to generate a large number of microjets, thereby preventing magnetic agglomeration of minerals in the magnetic field and achieving the effect of online cleaning of ore concentrates, reducing the mud content in the minerals, and improving the recovery rate and grade of the concentrates. However, the ultrasonic equipment is complex in design and difficult to operate, and the ultrasonic waves are difficult to control accurately. The ultrasonic equipment is set on the outer wall of the rotating ring, and the ultrasonic waves do not directly contact the slurry, which reduces the ability to prevent magnetic agglomeration. The ultrasonic magnetic separation capacity range is limited and its practicality is low. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention provides a method for weakening the magnetic agglomeration of magnetite before separation. A wind blowing process is added after the conventional demagnetization method to weaken the magnetic agglomeration phenomenon; the turbulence formed by the wind blowing destroys or eliminates the magnetic inclusions in the ore pulp; thus preparing for the subsequent magnetic separation and improving the grade of the concentrate in the subsequent separation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for weakening magnetic agglomeration of magnetite before separation. The method connects an air supply duct to the slurry supply duct after the demagnetizer. Air is blown into the air supply duct to create turbulent flow in the slurry. The wind blows away the magnetic agglomeration of mineral particles in the slurry, and the residual magnetism of magnetic materials in the slurry caused by the previous magnetic separation is weakened by mutual collision. The method specifically includes the following contents:

[0007] Magnetite magnetic separation process: first stage magnetic separator → traditional demagnetizer → wind blowing → second stage magnetic separator → concentrate;

[0008] The ore pulp speed v in the ore pulp pipeline is 0.2-5 m / s, and the ore slag particle size of -200 mesh accounts for 70-90% in the ore pulp.

[0009] The wind pressure P of the wind blowing is 0.30-2 MPa, the pipeline diameter wind volume Q is 0.5-10 m / min, and the ore pulp in the ore pulp pipeline reaches a turbulent effect. 3

[0010] Further, the air supply pipeline is arranged below and below the side of the ore pulp pipeline.

[0011] Further, the ore pulp pipeline and the air supply pipeline are coupled at an angle of 45°-90°.

[0012] Further, the diameter ratio of the ore pulp pipeline to the air supply pipeline is 5-10.

[0013] Further, the ore grade of the magnetic separation concentrate after the wind blowing is improved by 0.1%-0.5%.

[0014] Further, the magnetic field strength of the magnetic separator is 1500-5000 Oersted, and is gradually weakened.

[0015] Compared with the prior art, the beneficial effects of the present application are:

[0016] 1) By blowing the ore pulp in the pipeline with wind, the ore pulp transported in the pipeline forms a turbulent phenomenon, and the magnetic body eliminates or weakens the magnetism due to mutual collision, and the ore pulp turbulence in the pipeline causes the magnetic minerals to collide with each other, thereby weakening or eliminating the magnetism, weakening the magnetic agglomeration phenomenon in the ore pulp, preparing for subsequent magnetic separation, improving the efficiency of subsequent magnetic separation, and improving the yield of magnetic separation.

[0017] 2) The magnetic chain formed by the magnetic agglomeration phenomenon is destroyed, the gangue minerals in the ore pulp are more limited to avoid being mixed with the magnetic minerals, the gangue minerals in the magnetic minerals are reduced, the effect of the late magnetic separation is improved, the selection rate of the magnetic minerals is improved, and the grade of the selected concentrate is improved by 0.1%-0.5%. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a process flow diagram of a method for weakening the magnetic agglomeration of magnetite before separation provided by the present application. DETAILED DESCRIPTION

[0019] The specific embodiments of the present application will be further described below in conjunction with the drawings:

[0020] For example, Figure 1 ​The figure shows the working principle of a method for weakening magnetic agglomeration before magnetite separation: In the traditional magnetic separation process, a wind purge process is added to the ore pulp that has been demagnetized by the demagnetizer after the initial separation. By using wind to purge the ore pulp in the pipeline during the process, turbulence is generated in the ore pulp transported in the pipeline, which destroys the magnetic chain formed by magnetic agglomeration. This minimizes the inclusion of gangue minerals in the ore pulp with magnetic minerals, and the ore pulp in the pipeline is fully dispersed, allowing for subsequent magnetic separation processes, thereby improving the effect of subsequent magnetic separation. At the same time, the collision of magnetic bodies will eliminate or weaken the magnetism, and the turbulent flow of the ore pulp in the pipeline will cause the magnetic minerals to collide with each other, weakening or even eliminating the magnetism, preparing for the subsequent separation and improving the grade of the concentrate.

[0021] like Figure 1 As shown, a method for weakening the magnetic agglomeration of magnetite before separation is disclosed. The method connects an air supply duct to the slurry supply duct after the demagnetizer. The air in the air supply duct is blown to form turbulent flow in the slurry, so that the mineral particles in the slurry are blown away by the wind and the magnetic agglomeration is dispersed. The residual magnetism of the magnetic materials in the slurry caused by the previous magnetic separation is weakened by mutual collision. The method specifically includes the following contents:

[0022] Magnetite magnetic separation process: first stage magnetic separator → traditional demagnetizer → wind blowing → second stage magnetic separator → concentrate;

[0023] The slurry velocity in the slurry delivery pipeline is v = 0.2 ~ 5m / s, and the slag particle size in the slurry is -200 mesh, accounting for 70% to 90%:

[0024] The wind pressure of wind sweeping is P = 0.30 ~ 2MPa, and the air volume of the pipe diameter is Q = 0.5 ~ 10m 3 / min, the slurry in the slurry delivery pipeline reaches a turbulent flow effect.

[0025] Furthermore, the air supply duct is arranged below and below the slurry supply duct.

[0026] Furthermore, the slurry delivery pipe and the air supply pipe are connected to form an angle of 45° to 90° along the flow direction.

[0027] Furthermore, the diameter ratio of the slurry delivery pipe to the air delivery pipe is 5 to 10.

[0028] Furthermore, the grade of the magnetically separated concentrate after the wind blowing is increased by 0.1% to 0.5%.

[0029] Furthermore, the magnetic field strength of the magnetic separator is 1500 to 5000 Oersteds and is gradually weakened.

[0030] Embodiment: The process parameters of the slurry in the slurry delivery pipe of the embodiment of the present invention are shown in Table 1; the process parameters of the wind blowing of the air supply pipe of the embodiment of the present invention are shown in Table 2; the comparison of the mineral processing grade parameters of the embodiment of the present invention and the mineral processing grade parameters of the traditional process is shown in Table 3.

[0031] The slurry delivery pipeline after the demagnetizer is connected to the air supply pipeline, and the air supply pipeline is connected at the lower position of the slurry delivery pipeline. The slurry delivery pipeline and the air supply pipeline are connected at a 60° angle, and the diameter ratio of the slurry delivery pipeline and the air supply pipeline is 8; the iron grade of the feed ore is 35%, and the particle size of -200 mesh accounts for 72%; after magnetic separation and tailings are discarded by the first-stage magnetic separator, the magnetic field strength of the first-stage magnetic separator is 3500 Oersted, and the concentrate is re-ground to -200 mesh, accounting for 85%. After demagnetization by the demagnetizer and wind blowing, it is fed into the second-stage magnetic separator for magnetic separation, and the magnetic field strength of the second-stage magnetic separator is 2500 Oersted.

[0032] Table 1 - Slurry process parameters

[0033] Slurry delivery pipeline slurry velocity v (m / s) Slag particle size -200 mesh proportion (%) Example 1.5 85

[0034] Table 2- Wind Blowing Process Parameters

[0035] Example Wind pressure P (MPa) <![CDATA[风量Q(m 3 / min)]]> Example 1 0.5 2.0 Example 2 1.0 2.7 Example 3 1.5 3.0

[0036] Table 3 - Comparison of the mineral processing grade parameters of the embodiment of the present invention and the mineral processing grade parameters of the traditional process

[0037] Example Iron grade (%) Iron concentrate recovery rate (%) Comparative Example 61.00 90.01 Example 1 61.21 90.04 Example 2 61.35 90.06 Example 3 61.38 90.07

[0038] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solutions and concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for weakening magnetic agglomeration of magnetite before separation, characterized in that: This method connects an air supply pipe to the slurry supply pipe after the demagnetizer. The air in the air supply pipe is blown to form turbulent flow in the slurry. The wind blows away the magnetic agglomeration of the mineral particles in the slurry, and the residual magnetism of the magnetic materials in the slurry caused by the previous magnetic separation is weakened by mutual collision. Specifically, it includes the following contents: Magnetite magnetic separation process: first stage magnetic separator → traditional demagnetizer → wind blowing → second stage magnetic separator → concentrate; The slurry velocity in the slurry delivery pipeline is v = 0.2 ~ 5m / s, and the slag particle size in the slurry is -200 mesh, accounting for 70% to 90%: The wind pressure of wind sweeping is P = 0.30 ~ 2MPa, and the air volume of the pipe diameter is Q = 0.5 ~ 10m 3 / min, the slurry in the slurry delivery pipeline reaches a turbulent flow effect.

2. The method for weakening magnetic agglomeration of magnetite before separation according to claim 1, characterized in that: The air supply duct is arranged below and below the slurry supply duct.

3. The method for weakening magnetic agglomeration of magnetite before separation according to claim 1, characterized in that: The slurry delivery pipe and the air delivery pipe are connected to form an angle of 45° to 90°.

4. The method for weakening magnetic agglomeration of magnetite before separation according to claim 1, characterized in that: The diameter ratio of the slurry delivery pipe to the air delivery pipe is 5 to 10.

5. The method for weakening magnetic agglomeration of magnetite before separation according to claim 1, characterized in that: After the wind blowing, the grade of the magnetically separated concentrate is increased by 0.1% to 0.5%.

6. The method for weakening magnetic agglomeration of magnetite before separation according to claim 1, characterized in that: The magnetic field strength of the magnetic separator is 1500 to 5000 Oersteds and is gradually weakened.

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