RU2464101C1 - Magnetohydrostatic separator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to dressing of minerals and density classification of mixes of various nonmagnetic materials. Proposed separator comprises magnetic system with hyperbolic-profile pole tips, chamber with magnetic fluid arranged in pole gap, loading and discharging devices. two or more pairs of pole tips make some sections of pole gaps. Note here that efficient density of magnetic fluid of adjacent section satisfies the condition p_k>p_k+1, where p is efficient density of magnetic fluid, k is number of sections. Every pair of pole tips is furnished with magnetic field intensity regulators. Separator is equipped with device to adjust magnetic system inclination to horizon from 0 to 45 degrees.

EFFECT: higher efficiency of separation.

6 cl, 4 dwg

Description

The invention relates to the field of mineral processing and processing of secondary raw materials and can be used for density separation of mixtures of various non-magnetic materials.

Known magneto-hydrostatic separator (USSR Author's Certificate No. 1041154, IPC B03C 1/30, 1983), comprising an electromagnetic system with pole tips of a hyperbolic profile, a chamber with magnetic fluid located in the gap between the pole tips, a feeder and receivers of separation products. The working surfaces of the pole pieces on the feeder side are located in a horizontal plane at an angle to each other, the opening of which is performed in the direction from the input end to the working surface, in which the source material is divided into two fractions - heavy and light.

The disadvantages of this separator are low selectivity, which reduces to dividing the entire source material into only two groups - heavy and light, and, as a result, low separation performance, if necessary, separation of the source material into several fractions of different density.

The prototype of the invention is a ferrohydrostatic separator (USSR Author's Certificate No. 1136840. IPC B03C 1/30, 1985), comprising a magnetic system with pole pieces having a hyperbolic profile in both vertical and horizontal planes, a chamber with magnetic fluid located in the pole gap, loading and unloading devices.

The disadvantages of this separator are the difficulty of manufacturing poles with a hyperbolic profile both in the vertical and horizontal planes, as well as low selectivity, which is reduced to dividing the entire source material into only two groups - heavy and light, and, as a consequence, low separation performance if necessary separation of the starting material into several fractions of different density.

The technical result is to increase the efficiency and productivity of the magneto-hydrostatic separator.

The specified technical result is achieved in that the magneto-hydrostatic separator, comprising a magnetic system with pole pieces having a hyperbolic profile in the vertical plane, a chamber with magnetic fluid located in the interpolar gap, a loading and unloading device, according to the invention is equipped with a device for adjusting the angle of inclination of the magnetic system to the horizontal in the range from 0 to 45 degrees, two or more pairs of pole pieces form the same number of sections of the pole gap, moreover, the effective density of the magnetic fluid of neighboring sections satisfies the condition ρ _k > ρ _{k + 1} , where ρ is the effective density of the magnetic fluid, k is the serial number of the plot, each pair of pole pieces is equipped with magnetic field intensity regulators. In a vertical secant plane, the profile of the working surface of the pole piece has either a hyperbolic shape, or a trapezoidal shape, or a polygonal shape. The edges of the working surface of the pole pieces are rounded. The magnetic field regulators are made in the form of ferromagnetic plates mounted with the possibility of vertical movement between each pole piece and the core of the magnetic system, and in the form of magnetic shunts installed with the possibility of vertical movement above each pair of pole pieces.

The design of the proposed magneto-hydrostatic separator is illustrated by the drawings shown in figures 1-4:

Figure 1. Magnetohydrostatic separator (front view and top view).

Figure 2. Magnetohydrostatic separator (left view).

Figure 3. The shape of the surface profile of the pole tip: (a) - hyperbolic profile; (b) a trapezoidal profile; (c) and (d) - polygonal profile.

Figure 4. The location of the magnetic shunt above the pole pieces.

The separator electromagnetic system (Figs. 1, 2) consists of a ferromagnetic core 1 with a magnetization winding 2. Along the length of the core in its upper part are pairwise symmetrical and parallel pole pieces 3, forming the number of sections of the interpolar gap corresponding to the number of pairs, expanding towards the output end of the separator (the drawings show an example of a separator with four pairs of pole pieces). A chamber 4 made of non-magnetic material is placed in the interpolar gap. In the chamber 4 there is a magnetic fluid 5, which is held due to the magnetic field created by the winding 2 when electric current I flows through it. The separator contains a loading device 6 and an unloading device with containers 7 for separation products, the number of containers corresponds to the number of sections of the pole gap and the number pairs of pole pieces 3. Between the core 1 and each pole piece there are ferromagnetic plates 8, when moving in a vertical direction between the heart 1 and ICOM pole piece an air gap Δ _1. Above each pair of pole pieces installed magnetic shunts 9 (figure 4), made in the form of plates of ferromagnetic material. The air gap Δ ₂ between the magnetic shunt 9 and the pair of pole pieces 3 is regulated by moving the shunt 9. The separator is equipped with a device for adjusting the angle α of the magnetic system to the horizon in the range from 0 to 45 degrees (not shown in the drawings).

In a vertical secant plane, the interpolar gap formed by pairs of pole pieces expands upward. The geometry of the working surface of the pole tip has either hyperbolic, or trapezoidal, or polygonal shape (figure 3).

The number of separated fractions in a mixture of non-magnetic materials is equal to the number of sections of the interpolar gap and the number of pairs of pole pieces. The magnitude of the interpolar gap between the pair of pole pieces, their profile geometry, the air gaps Δ ₁ and Δ ₂ for each pair of pole pieces are selected from the condition ρ _k > ρ _{k + 1} , where ρ is the effective density of the magnetic fluid, k is the serial number of the section.

In the inventive magnetohydrostatic separator, the effect of changing the effective density of a magnetic fluid located in an inhomogeneous magnetic field is used. In this case, the magnetic force f _m acts per unit volume of the magnetic fluid in the direction of increasing magnetic field strength

f _M = µ ₀ · M · | ∇H |,

where μ ₀ is the magnetic permeability of the vacuum, M is the magnetization of the magnetic fluid, | ∇H | - modulus of the gradient of the magnetic field.

If the directions of gravity (ρ _Ж · g) and magnetic force f _m coincide, then the effective density of the magnetic fluid ρ exceeds the density ρ _{Ж of the} magnetic fluid in the absence of a magnetic field

By adjusting the effective density of the magnetic fluid by changing the magnetic field, one can influence the magnitude of the Archimedean force and carry out the separation of non-magnetic materials by their density.

For the first pair of pole pieces, the minimum gap δ ₁ between them, the geometry of their profile and the current I in the winding are selected from the condition that the effective density of the magnetic fluid exceeds the density of the heaviest fraction in the mixture of non-magnetic materials

ρ ₁ > (ρ _Fmax. = ρ _{Ф, 1} ),

where ρ ₁ is the effective density of the magnetic fluid in the first section, ρ _{Ф max.} is the density of the heaviest fraction in the mixture of non-magnetic materials, ρ _{Ф, 1} is the density of the heaviest fraction in the mixture of non-magnetic materials in the first section.

As a result, all fractions of the initial mixture will be on the surface of the magnetic fluid.

For the second and each next pair of pole pieces, the minimum gap δ _to between them, the geometry of their profile are selected from the condition of separation of a fraction with a density ρ _{Ф (k-1)} from the mixture:

R _{f, k-1} > ρ _k > ρ _{f, k} ,

where ρ _k is the effective density of the magnetic fluid in the k-th section, P _{Ф, k-1} is the density of the heaviest fraction in the mixture of non-magnetic materials in the k-1st section. ρ _{Ф, k} is the density of the heaviest fraction in the mixture of non-magnetic materials in the k-th section.

The specific magnetic force f _m in the upper half of the working gap filled with magnetic fluid can vary from a maximum value of f _{m max} to a minimum value of f _{m min} . Accordingly, the effective density of the magnetic fluid varies from ρ _max to ρ _min .

The main requirement when choosing the profile geometry of a pair of pole pieces in each section, starting from the second (k≥2), is that in the upper half of the interpolar gap filled with magnetic fluid, the difference in the values of the effective density should not exceed the difference in the densities of the separated fractions

(ρ _{k max} -ρ _{k min} ) <(ρ _{Ф (k-1)} -ρ _{Ф k} ).

The edges on the surface of the pole pieces facing the interpolar gap are rounded to exclude the concentration of magnetic lines of force and a sharp local change in the effective density of the magnetic fluid.

Magnetohydrostatic separator operates as follows.

In the magnetization winding 2, the current I is set, which is necessary to hold the required amount of magnetic fluid 5 in the separator’s working gap. Using the tilt angle adjustment device, the magnetic separator system is set at an angle α to the horizontal (0 <α <45 °), resulting in floating the surface of the magnetic fluid particles will move along this surface in the direction of the output end of the separator. The angle α is selected from the conditions for ensuring the necessary performance and accuracy of the separator operation process. From the loading device 6 to the surface of the magnetic fluid in the area of the first stage enters a mixture of non-magnetic particles to be separated. The magnitude of the current I in the winding 2 proportionally affects the magnitude of the magnetic field and the magnetic force f _m The current is regulated so that as the particles move along the inclined surface of the magnetic fluid, the fractions are sequentially divided by density in each section of the interpolar gap. The accuracy of the separation of fractions by density is improved by additionally adjusting the magnetic field strength within each section of the gap by moving the plates 8 and / or magnetic shunt 9. When lifting the plates 8, the magnetic resistance for magnetic flux due to the gap Δ ₁ increases, which leads to a decrease in the magnetic field in the gap and a decrease in the force f _m When lowering the magnetic shunt 9 (Fig. 4), the gap Δ ₂ is reduced and the effect of shunting the magnetic flux is enhanced, as a result of which the magnetic field strength in the interpolar gap and the force f _m decrease.

As a result, the mixture of non-magnetic materials coming from the loading device 6 (FIG. 2) is sorted by density in separate fractions falling into containers 7. In the proposed magneto-hydrostatic separator, when the separated mixture is loaded once, the number of fractions separated by density increases, which increases productivity and efficiency operation of a magnetohydrostatic separator.

Claims (6)

1. Magnetohydrostatic separator comprising a magnetic system with pole pieces having a hyperbolic profile in the vertical plane, a chamber with magnetic fluid located in the pole gap, loading and unloading devices, characterized in that two or more pairs of pole pieces form the same number of sections pole gap, the effective density of the magnetic fluid adjacent segments satisfies the condition ρ _k = ρ _{k + 1,} where ρ - effective density of the magnetic fluid, k - smacking kovy section number, each pair of pole pieces provided with a magnetic field strength regulators, a separator provided with a control device the inclination angle of the magnetic system to the horizontal in the range of 0 to 45 °. 2. The magnetohydrostatic separator according to claim 1, characterized in that in the vertical secant plane, the profile of the working surface of the pole piece has either a hyperbolic shape, or a trapezoidal shape, or a polygonal shape. 3. The magnetohydrostatic separator according to claim 2, characterized in that the edges of the working surface of the pole pieces are rounded. 4. The magnetohydrostatic separator according to claim 1, characterized in that the magnetic field regulators are made in the form of ferromagnetic plates mounted with the possibility of vertical movement between each pole piece and the core of the magnetic system, and in the form of magnetic shunts installed with the possibility of vertical movement above each a pair of pole pieces. 5. The magnetohydrostatic separator according to claim 1, characterized in that the magnetic field regulators are made only in the form of ferromagnetic plates mounted with the possibility of vertical movement between each pole piece and the core of the magnetic system. 6. The magnetohydrostatic separator according to claim 1, characterized in that the magnetic field regulators are made only in the form of magnetic shunts mounted with the possibility of vertical movement over each pair of pole pieces.

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