WO2016041534A1

WO2016041534A1 - Strong magnetic field magnetic separator

Info

Publication number: WO2016041534A1
Application number: PCT/DE2015/000428
Authority: WO
Inventors: Mario Gerards; Sebastian-Henry Müller; Marco Steinberg
Original assignee: Mbe Coal & Minerals Technology Gmbh
Priority date: 2014-09-17
Filing date: 2015-08-27
Publication date: 2016-03-24
Also published as: DE102014013459A1

Abstract

The invention relates to a strong magnetic field magnetic separator for separating solid particles with different magnetic susceptibilities that are suspended in a carrier medium, having a rotor (1) with at least one ferromagnetic rotor disc (2a, 2b), an arrangement of open containers (matrix boxes) (5) at the periphery of each rotor disc (2a, 2b), wherein ferromagnetic bodies (matrix) (6) for the separating operation are arranged in the interior, at least one apparatus (10) for transferring the suspension into the matrix boxes (5), at least one apparatus (12, 14) for discharging retained particle fractions, and a statically arranged magnet system having at least one yoke (8a, 8b), wherein the limbs of each yoke (8a, 8b) bear magnetic coils (7) and the pole shoes (9a, 9b, 9c, 9d) are arranged and the coil currents are directed such that two mutually opposite pole shoes (9a, 9b, 9c, 9d) of different magnetic polarities are located at the height of each rotor disc (2a, 2b) at the periphery thereof. According to the invention, provision is made for the at least one yoke (8a, 8b) to consist of a) a magnetic material composed of at least 99.65% pure iron, preferably at least 99.85%, with a maximum carbon content of 0.02%, preferably at most 0.01%, or b) an iron-cobalt alloy with a cobalt content of between 15% and 50%, preferably between 15% and 20%.

Description

Strong-field magnetic separator

The invention relates to a Starkfeldmagnetscheider for separating suspended in a carrier medium solid particles with different magnetic susceptibility, having a rotor rotatably driven about an axis with at least one ferromagnetic rotor disk, wherein the axis has an angle, preferably a right angle to the horizontal, an annular Arrangement of open containers (matrix boxes) at the outer edge of each rotor disk for the medium to flow through the matrix boxes, wherein the flow direction is preferably directed from top to bottom and wherein inside the matrix boxes paramagnetic bodies (matrix) are arranged for the separation process, at least a device for discharging the carrier medium with the suspended solid particles into the matrix boxes, at least one device for discharging particle fractions retained in the matrix boxes due to magnetic attraction, and a statically arranged magnet system having at least one yoke for forming a closed magnetic circuit (with gaps in the region of the at least one rotor disk), wherein the legs of each yoke carry at least one magnetic coil and wherein the ends of the at least one yoke formed as pole shoes are arranged and the Current flows through the magnetic coils are directed so that at the level of each rotor disk and close to the periphery of the rotor disk are two mutually opposite pole pieces of different magnetic polarity.

confirmation copy Strong field magnetic separators are used to separate fractions of substances with different magnetizability, which can be characterized by specifying the magnetic susceptibility, in mixtures of solid particles, which are usually in the form of small grains. Of particular importance is this method in the enrichment, treatment and recovery of iron ores and other minerals. Compositions in granular form are suspended in a mostly liquid carrier medium (turbidity) and exposed to the effect of a strong magnetic field transversely to their direction of flow or to the gravitational field. Non-magnetizable and only extremely weak magnetic particles remain unaffected by the magnetic field and are thus separated from the magnetizable and deflected by the magnetic field and retained particles. The selectivity of this sorting process depends primarily on the magnetic field. The higher the field strength or the resulting magnetic flux density, the weaker the magnetizable particles can be deposited despite counteracting weight, flow and interparticular frictional forces. The effectiveness of this process determines the quality of the process of removing interfering or enriching or recovering valuable magnetically susceptible matter. The material throughput rates, which must be realized by the high-field magnetic separators used in the mineral ore industry, amount to several hundred tons per hour.

From the prior art, for example. From the patent US 3,830,367, as well as from many used in industrial practice magnetic separators, eg. The JONES ^® WHIMS (Wet High Intensity Magnetic Separator), high field magnetic separators are known in which, according to basic principle in the liquid carrier medium , mostly water, suspended granular particles are abandoned in up-and-down apertured boxes. The individual boxes are arranged like a ring around a horizontal rotor disk made of a material with high magnetic permeability or Suszeptibiltät. By rotating the disc, the boxes are replaced by a strong magnetic field between two pole pieces. leads, which are arranged opposite one another, with a small gap spaced apart like a pair of tongs on peripheral portions of the rotor disk or the outer box walls. Therefore, a magnetic flux passes over the disk, and soft magnetic bodies, called matrix, arranged inside the boxes are magnetized in front of the pole shoes. The magnetically susceptible portions of the suspension remain adhered to the surfaces of the matrix, while the non-or extremely weak magnetic particles fall through the matrix boxes down. In a continuous operation, the matrix boxes each rotate out of the area in front of a pole piece. On the way to the opposite pole piece, in particular on the middle of the path, where the magnetic field influence is the lowest, the retained magnetic particles can be removed and discharged under high pressure, for example with the aid of a cleaning fluid stream. Even non-magnetic material residues can be removed. Decisive for the efficiency of the separation process is a high magnetic force in the region of the separation space, ie in the matrices. The reason for the structure of the magnetic field or magnetic flux over the rotor disk is the generation of strong magnetic fields in the interior of current-carrying coils. These are connected in pairs by a yoke, in which the external magnetic field generates a magnetic flux, which flows through the yoke and its pole shoes like a circle and the rotor disks with the boxes.

The applicability of the Starkfe.ldmagnetscheider described is due in two ways. First, there is always a limited separation efficiency, given by the magnetic susceptibility limit below which very weakly magnetizable particles are not separated on average. This depends on the magnetic field strength in the separation space, to which, in addition to influences of material and shape of the matrix as well as the design of the pole shoes or yokes, ultimately the strength of the magnetic flux through the yokes has the most important influence. This is limited by the material-specific saturation of the magnetic see polarization (or the magnetization or magnetic flux density / induction) of the yoke, as it results for its ferromagnetic material from the associated hysteresis curve. In the prior art, the separation efficiency in this regard is essentially given by the magnetic saturation polarization of the structural steels commonly used for the yokes. Second, the practicality of a Starkfeldmagnetscheiders in practice due to its energy efficiency. The main energy requirement arises for the current flow in the magnetic coils for generating a magnetic flux density in the yokes, which is caused by the coil magnetic field, as high as possible. Again, in the prior art, the energy efficiency of the ratio of the magnetic flux depending on the external magnetic field by the hysteresis of the ferromagnets used for the yokes, especially mild steel, limited. Energy efficiency is always related to the economically relevant factors, such as, in particular, the investment and maintenance costs required for this purpose. For a practice-relevant improvement of high-field magnetic separators, the expert thus raises an optimization problem that includes both the separation efficiency and the economic efficiency of the plant, given mainly on their energy needs.

The object of the invention is therefore to provide a high-field magnetic separator for the separation of suspended in a carrier medium solid particles with different magnetic susceptibility available, which has an increased separation efficiency and improved energy efficiency.

The object of the invention is achieved by a high-field magnetic separator for the separation of suspended in a carrier medium solid particles with different magnetic susceptibility with the features of claim 1. Further advantageous embodiments are specified in the subclaims to claim 1. According to the invention, a high-field magnetic separator is provided, in the magnet system of which each yoke is made of a magnetic material having a magnetic saturation polarization of at least 2.0 T, the magnetic material of each yoke consisting of at least 99.65% pure iron, preferably at least 99.85 %, at a maximum carbon content of 0.02%, preferably at most 0.01%, or is an iron-cobalt alloy having a cobalt content of between 15% and 50%, preferably between 15% and 20%. Data for the magnetic saturation polarization (saturation induction) basically refer to the theoretical, ideal values of the corresponding magnetic material. Due to various production steps, inhomogeneities and similar influences, which are partly associated with heat, the actual value for a yoke made of this magnetic material may deviate from these values which are to be regarded as guidelines. In conventional high-field magnetic separators, the yokes are usually made of structural steel. The typical unalloyed structural steel S235JR (or ST 37), for example, has mechanical physical properties that make it suitable for production and use in high-field magnetic separators. Its carbon content is less than about 0.15%. Its particularly advantageous magnetic saturation polarization (or saturation induction) is 1.9 T. The materials proposed according to the invention clearly exceed the magnetic properties of previous yoke materials in high-field magnetic separators. They can be used to generate magnetic fields with higher field strengths, which is advantageous for the separation and recovery of particularly weak magnetic components from the solid particles suspended in the carrier medium and beyond the hitherto available separability possibilities, for example in the enrichment of ores or in recovery processes , reaches out.

The magnetic material (a) of the first alternative according to the invention for the yoke material (for example, under the trade name ARMCO traded ^®) has values for the saturation magnetic polarization by about 2.15 T, so that the Strong field magnetic separator has an increased separation efficiency. In a typical embodiment (sometimes classified as so-called grade 3), this magnetic material consists of 99.85% Fe, 0.01% C, 0.08% Mn, 0.01% P, 0.005% S, 0.005% N, 0 , 03% Cu and 0.01% Sn; It has a magnetic saturation polarization of 2.15 T. The lower the carbon content of this material (a), the better it can be cold formed in the production of the yoke, welding and other mechanical processing steps undergo. The corrosion resistance is very high and the mechanical static properties of this material allow use as a yoke carrying a coil in the typical dimension of magnetic separators.

Test measurements have also shown or confirmed under the conditions of use which are typical for high field magnetic separators that the magnetic material (a) has a very narrow hysteresis curve and a correspondingly favorable ratio of the magnetic flux density B in the yokes to the magnetic field strength H of the Coil field has. Thus, a Starkfeldmagnetscheider with yokes from the magnetic material (a) in operation for the same magnetic field strengths lower, mainly for the construction of the magnetic field of the current-carrying magnetic coils energy consumption than the conventional, such as equipped with steel yokes Starkfeldmagnetscheider. This means in particular for the continuous continuous operation and at large, suitable for a high material throughput dimensions a significant economic advantage. Furthermore, then, economically favorable, the solenoid coils used can be smaller and also need to be cooled correspondingly less. Previous tests even make energy savings of the order of 50% seem possible.

In the feasibility assessment of possible yoke magnetic materials, the skilled person is faced with an optimization problem, in addition to the magnetic properties and the physical or material properties of the Magnetic material are also the economic factors for the investment and operation of the strong field magnetic separators are included. The material in question must be available on the market in the quantities required for large-scale production of magnetic separators, at a price that allows for the economically profitable use of a high-field magnetic separator. Because of the above-mentioned improvements in magnetic properties over conventional high-field magnetic separators and because of the good availability of the material (a) at current commercial prices, material (a) provides a suitable solution to the mentioned optimization problem for an economically favorable increase in efficiency of high-field magnetic separators by improved yoke material represents.

The inventively proposed second alternative of a magnetic material for the yokes, material (b), consists in the use of iron-cobalt alloys. Already with a cobalt content of about 15%, such alloys have magnetic saturation polarizations of more than 2.1 T, which cause an increased separation efficiency of the magnetic separator. With a cobalt content of about 50% (and 50% Fe, possibly also with low admixtures of vanadium which are favorable for material processing), the saturation polarization is even around 2.35 T. Nonetheless, iron-cobalt alloys come with such high cobalt contents only in exceptional cases for use in high-field magnetic separators, since the prices of the material (b) increase significantly with increasing cobalt content. Furthermore, the high cobalt alloys exhibit difficult mechanical physical properties for the yoke manufacturing process. Cobalt contents of between about 15% and 20% are therefore preferred. A typical embodiment is given by the alloy with proportions of 17% Co, 81% Fe and 2% Cr; In this case, material (b) has a magnetic saturation polarization of more than 2.2 T. Besides the advantage of the high selectivity for very weak magnetic particles that can be achieved with it In the case of these alloys, too, according to the measured hysteresis behavior, a lower energy requirement of the high-field magnetic separator occurs in comparison to systems with Jochen made of structural steel. Although iron-cobalt alloys are available in sufficient quantities, the current commercial prices are significant, so from a cost point of view for normal operation normally the solution with material (a) is preferable. The use of material (b) is in individual cases, especially in smaller sized Starkfeldmagnetscheidern, but then close if very high magnetic flux densities are required for the targeted enrichment, recovery or separation of a special, very weak magnetic material component in the feed mixture. In order to reduce the investment costs, it is also possible, if necessary, not to manufacture all yokes made of an iron-cobalt alloy in the case of high-field magnetic separators with a plurality of rotor disks.

While for small throughputs and / or for test purposes high field magnetic separators with rotors consisting of only one rotor disk and in which the two associated opposite pole shoes are connected with only one yoke, more than one rotor disk are advantageously to be provided in order to achieve larger throughput quantities. A typical embodiment of the invention therefore provides that the rotor consists of two rotor disks arranged one below the other, spaced apart and rotatable about a common axis. In favor of short, low-loss paths of the magnetic flux and in terms of the lowest possible cost of materials in the yokes here two yokes are provided, which lead in approximately C-shaped (or U-shaped) in each case from one to the other rotor disk. The thus each two interconnected, stacked pole pieces have, as well as each two opposing pole pieces by appropriate adjustment of the directions of electrical current flow in the coils opposite magnetic polarities. In a further embodiment, the strength of the magnetic field between the for. By the respective coil pairs a pole piece belonging to a rotor disk, regardless of the strength of the magnetic field between the pole piece belonging to the other rotor disc controllable. In particular, this feature allows operation of the high-field magnetic separator in which the material content of the matrix boxes of the lower rotor disk has passed through the matrices of the upper rotor disk and has leaked out without adhesion directly to the carrier medium, but still due to impacts and friction may contain magnetic particles entrained by non-magnetic particles. Likewise, a hindrance with particularly high magnetic field strengths for depositing a very weakly magnetized particle fraction is conceivable here in a second stage. The rotational speed must be adapted to the resulting material throughput.

Insofar as the actual cutting process takes place in the interior of the matrix boxes by retention of the magnetic particles on the matrix, the geometric design of the surfaces of the soft magnetic bodies in the matrix boxes is of particular importance. An advantageous embodiment of the invention provides that the matrices are formed of sheets, which are formed of wear-resistant, stainless, magnetizable steel. The sheets are spaced from each other, wherein the distance is adjustable, so that the matrices can be adapted to the flow rate of the carrier medium with the suspended feed, to the average grain sizes and the magnetic properties of the particle fractions to be separated. In particular, disadvantageous backflow effects can be avoided by adding flow paths. It has been found that parallel checker plates (scoring plates) are particularly suitable for providing a large surface area for effective adhesion of the magnetically susceptible particles, as well as a suitable flow path and a sufficiently long pass time of the suspended particles through the matrix guarantee. Furthermore, the cleaning of the plates during the Austragsvorgang the retained particles can be perform comparatively quickly. In addition, the geometry of the matrix is important for the field strength distribution of the external magnetic field in the matrix boxes. Due to suitable field gradients, said corrugated plate arrangement causes locally increased magnetic field strengths, which have an advantageous effect on the process of separating and retaining the magnetic or in some cases only weakly magnetic particles.

The operation of the Starkfeldmagnetscheiders based on the fact that forms current flow in the coils, a magnetic flux through the yoke or yokes and their acting as a coil cores limbs, through the pole pieces and the rotor disc (s) and through the total flux a narrowing gap (the narrow gap between the pole pieces and the outer wall of the matrix boxes as well as the gaps in the dies) creates a closed magnetic circuit. Each rotor disk is therefore to manufacture in favor of a lossless magnetic flux from a magnetic material with favorable properties, in particular with high magnetic saturation induction. This is typical in conventional magnetic separators. used steel with a low carbon content. In order to improve the magnetic flux even further, an embodiment of the invention provides for the rotor disks similar to the Jochen use a magnetic material with high saturation induction at the same time suitable mechanical properties and in special cases still acceptable investment costs. It is therefore proposed to manufacture the at least one rotor disk of the rotor from a magnetic material, which consists of at least 99.65% pure iron, preferably of at least 99.85% pure iron, with a maximum carbon content of 0.02%, preferably at a maximum carbon content of 0.01%.

In an advantageous embodiment of the invention Starkfeldmagnetscheiders is provided for the device of the crop, ie the supply of the carrier medium with the suspended in it small, grain-like solid particles to the matrix boxes, and to arrange for the devices for discharging the particle fractions retained on the matrices over the circumference of the rotor disks, that is distributed over the ring formed by the matrix boxes Gutertgabe- and Austragvorrichtungen, as known from the prior art (see US 3,830,367) are already known in itself and are used for example in the magnetic separators of the trademark JONES ^®. Accordingly, on the way of each matrix box around the circumference of the associated rotor disk around the carrier medium, for example water, with the therein suspended, typically granular solid particles by means of a Gutzuführungsleitung continuously at a Aufgabestelle in the upwardly open matrix boxes initiated at the beginning of the arcuate movement path the matrix boxes is arranged through the immediately before a pole piece located area. The non-magnetic or extremely weak magnetic material component falls gravitationally down through the matrix boxes.

A first dispensing device, the washing device, is disposed at the other end of the area in front of the pole piece. By flowing with a comparatively low pressure washing fluid stream, typically water, are here between the magnetic grains loose trapped, remaining remnants of non-magnetic or extremely weak magnetic solid particles from the matrix boxes removed down. A further discharge device, the rinsing device, for discharging the magnetic particle fraction retained in the matrix boxes due to the remaining magnetic action, is arranged in the middle of the rotation path between the mutually opposite pole shoes. Here, due to the different polarity of the pole shoes, the magnetic field is largely neutralized, so that parts of the magnetic particle fraction fall gravitationally out of the matrix boxes. Still retained portions are removed under comparatively high pressure with a rinsing fluid stream, typically water, and optionally also with additional use of a high pressure gas stream and discharged down. The downstairs Fluids and particles emerging from the matrix boxes are collected in collecting channels and discharged accordingly. The arrangement of the three stations described so far is repeated symmetrically on the other side, ie on the return path of the matrix boxes from the second to the first pole piece. The embodiment of the invention is not fixed to the details of the Gutein- and Gutaustrags described here; rather, the illustrations of the devices are to be understood as a basic principle that is easy to modify by a person skilled in the art.

The invention will be explained in more detail with reference to the following figure. It shows:

Fig. 1 shows a Starkfeldmagnetscheider invention in the embodiment with two rotor disks.

In Figure 1, a Starkfeldmagnetscheider is shown schematically with a rotor 1, whose (in the illustrated embodiment) two rotor discs 2a, 2b arranged horizontally and one above the other and rotatably mounted on a shaft 3 and in the operation of Starkfeldmagnetscheiders around the axis defined by the shaft vertical axis 4 turn. The inner region of the rotor disks 2a, 2b consists of ferromagnetic material. Ring-like around the circumference of the rotor disks 2a, 2b, a plurality of matrix boxes 5 are arranged which have up and down openings and in the interior of which soft magnetic bodies each form a so-called matrix 6. In the exemplary embodiment, the matrix 6 consists of spaced-apart, wear-resistant, corrugated steel sheets whose surfaces in the magnetized state are suitable for the adhesion of magnetically susceptible particles. By current flow in the magnetic coils 7, a magnetic field is generated in the interior thereof. The statically mounted magnetic coils 7 are supported by the legs acting as a coil core each of a yoke 8a, 8b, wherein the pole pieces 9a, 9b, 9c, 9d of the C- or U-shaped yokes 8a, 8b at the level of the rotor disks 2a, 2b in pairs each other lying exactly opposite in a portion of the circumference of the rotor disks 2a, 2b, the rotor disks 2a, 2b tong-like, but spaced by a narrow, filled with air gap. The two pole shoes 9a, 9b, 9c, 9d of each yoke 8a, 8b are arranged one above the other on the same side of the rotor 1, since each yoke 8a, 8b leads geometrically from the upper rotor disk 2a to the lower rotor disk 2b. The current flow in the magnetic coils 7 is directed so that on a rotor disk 2a _; , 2b opposite pole pieces 9a, 9b, 9c, 9d have different magnetic polarity.

When current flows in the magnetic coils 7, a magnetic flux is generated by the magnetic field in the interior of the yokes 8a, 8b. The magnetic flux forms via the yokes 8a, 8b, the pole pieces 9a, 9b, 9c, 9d and the rotor disks 2a, 2b with the matrix boxes 5 a closed magnetic circuit (with gaps in the region of the two rotor disks 2a, 2b). According to the proposal of the invention, each Joel) 8a, 8b consists either of a magnetic material of at least 99.65% pure iron, preferably at least 99.85%, at a maximum carbon content of 0.02%, preferably at most 0.01%, or from an iron-cobalt alloy having a cobalt content between 15% and 50%, preferably between 15% and 20%. The resulting magnetic saturation polarizations of the magnetic materials of the yokes 8a, 8b of more than 2.0 T (guide value) lead to high magnetic field strengths in the interior of the matrix boxes 5, where the separation of the magnetically susceptible particles takes place, and thus to a high separation efficiency of Starkfeldmag- netscheiders. In addition, the favorable hysteresis properties of the two magnetic materials result in a reduced energy requirement of the magnetic coils 7 compared with conventional solid state force majors equipped with steel yokes. to an improved energy efficiency of the plant.

According to the previously known method of operation of the wet-operated high-field magnetic separator type described here, the suspension of carrier medium, for example, water ser, and the fine-grained solid particles! n by Gutzuführungsleitungen a Gutaufgabevorrichtung 10 at the corner of each pole piece 9a, 9b, 9c, 9d continuously fed into the rotating ring of matrix boxes 5. While most of the non-magnetic and extremely weak magnetic particles exit downwards from the respective matrix box 5 and are discharged via a collecting channel 11, the magnetically sufficiently susceptible particles are retained on the matrix 6 under the influence of the magnetic field. By inclusion and friction, a proportion of non-magnetic particles is retained. This is removed by rotation of the area in front of the respective pole piece 9a, 9b, 9c, 9d by means of a washing fluid flow (not shown) arranged at the other corner of the respective pole piece 9a, 9b, 9c, 9d and derived trungsleitungen 13. The magnetized particle fraction retained on the matrices 6 falls in the magnetically almost neutral middle region of the rotation path between the pole shoes partly out of the matrix boxes 5 due to gravity. The remaining magnetic particle fraction is in each case determined by means of a flushing device 14 arranged in the center using a flushing fluid flow (not shown). which usually has to have a higher pressure than the washing fluid stream, removed from the matrix boxes 5 and discharged through associated discharge lines 15. After passing through these stations, the desired sorting is done.

The described Starkfeldmagnetscheider is stored in a stable, preferably made of steel frame (not shown). LIST OF REFERENCE NUMBERS

Rotor 9a, 9b, 9c, 9d Polschuh a rotor disk (upper) 10 Gutaufgabevorrichtung b rotor disk (lower) 11 collecting channel

Wave 12 washing device

Axis 13 discharge line (washing device)

matrix box

14 flushing device

matrix

15 discharge line (Spülvorrich¬

solenoid

tung)

a, 8b yoke

Claims

P A T E N T A N S P R E C H E

High-field magnetic separator for separating solid particles suspended in a carrier medium with different magnetic susceptibility,

including

a rotor (1) driven rotatably about an axis (4) with at least one ferromagnetic rotor disk (2a, 2b), wherein the axis (4) has an angle, preferably a right angle, to the horizontal,

an annular arrangement of open containers (matrix boxes) (5) on the outer edge of each rotor disk (2a, 2b) for the passage of the carrier medium through the matrix boxes (5), wherein

the flow direction is preferably directed from top to bottom, and

inside the matrix boxes (5) ferromagnetic bodies (matrix) (6) are arranged for the separation process,

at least one device for discharging the carrier medium with the suspended solid particles into the matrix boxes (5),

at least one device for discharging particle fractions retained due to magnetic attraction in the matrix boxes (5), and

a statically arranged magnet system having at least one yoke (8a, 8b) for forming a closed magnetic circuit (with gaps in the region of the at least one rotor disk (2a, 2b)), wherein

the legs of each yoke (8a, 8b) each carry at least one magnetic coil (7), and

the ends of the at least one yoke (8a, 8b) formed as pole pieces (9a, 9b, 9c, 9d) are arranged in such a way and the current flows through the magnet coils (7) are directed so that at the level of each rotor disc (2a, 2b) and two mutually opposite pole shoes (9a, 9b, 9c, 9d) of different magnetic polarity are located close to the periphery of the rotor disk (2a, 2b),

characterized in that

the at least one yoke (8a, 8b) is made of a magnetic material having a magnetic saturation polarization of at least 2.0T selected from

a) magnetic material of at least 99.65% pure iron, preferably at least 99.85%, with a maximum carbon content of 0.02%, preferably at most 0.01%, and

b) iron-cobalt alloy having a cobalt content between 15% and 50%, preferably between 15% and 20%.

2. Strong field magnetic separator according to claim 1,

characterized in that

the rotor (1) consists of two mutually spaced, spaced-apart and about a common axis (4) rotatable rotor discs (2a, 2b), and

the magnet system consists of two yokes (8a, 8) which each lead C-shaped from the upper to the lower rotor disk (2a, 2b).

3. Strong field magnetic separator according to claim 2,

characterized in that

the strength of the magnetic field between the pole pieces (9a, 9b) belonging to one rotor disk (2a) can be regulated independently of the strength of the magnetic field between the pole pieces (9c, 9d) belonging to the other rotor disk (2b).

4. Strong field magnetic separator according to one of claims 1 to 3,

characterized in that

the matrix (6) in the matrix boxes (5) consists of spaced, corrugated steel sheets, wherein the distance of the steel sheets is adjustable to one another.

5. Strong field magnetic separator according to one of claims 1 to 4,

characterized in that

relative to the rotation path of a matrix box (5) along the circumference of a rotor disk (2a, 2b) the at least one device (10) for feeding the carrier medium with the suspended solid particles into the matrix boxes (5) at the beginning of the area in front of a pole piece (9a, 9b, 9c, 9d) is arranged,

at least one device (washing device) (12) for discharging remaining residues of non-magnetic solid particles from the matrix boxes (5) is provided, which is arranged in each case at the end of the area in front of a pole piece (9a, 9b, 9c, 9d) and a wash - Has idstrom for removing the remaining, non-magnetic solid particles, and

at least one device (flushing device) (14) is provided for discharging the magnetic particle fraction retained in the matrix boxes (5), the at least one flushing device (14) in each case being centered on the rotation path between the pole shoes (9a, 9b, 9c, 9d) is arranged and has a flushing fluid stream for discharging the magnetic solid particles.

6. Strong field magnetic separator according to one of claims 1 to 5, characterized in that

the at least one rotor disk (2a, 2b) of the rotor (1) is made of a magnetic material which consists of at least 99.65% pure iron, preferably

at least 99.85% pure iron, at a maximum carbon content of 0.02%, preferably at a maximum carbon content of 0.01%.