FR2648058A1 - METHOD FOR ELECTRODYNAMIC SEPARATION OF CURRENT CONDUCTIVE NON-FERROMAGNETIC PARTICLES AND DEVICE FOR CARRYING OUT SAID METHOD - Google Patents

Abstract

The invention relates to a device for the electrodynamic separation of electrically conductive non-ferromagnetic particles comprising forming a high-frequency electromagnetic field and introducing into this field a powdery material to be separated which contains electromagnetic particles having different values of electrical conductivity. According to the invention, an electromagnetic circuit comprises a linear inductor 5 with one turn which is surrounded, at least over part of its length, by a U-shaped core 6, the inductor being arranged below the bearing surface d 'a means 10 for the introduction of the material to be separated so that the axis of the inductor 5 is parallel with the plane of the bearing surface of the means 10. The invention applies in particular to the enrichment of non-minerals. ferrous and noble metals and for the extraction of non-ferrous metals from a mixture of solid powdery materials as well as for the separation of particles of non-ferrous metals according to their electrical conductivity.

Description

The present invention relates to metallurgy

  non-ferrous and secondary metals and can be used

  for the concentration of non-ferrous and noble metal ores and for the extraction of non-ferrous metals from a mixture of solid pulverulent materials, in particular for the separation of fragmented complex metal waste, as well as for the separation of particles

  non-ferrous metals according to their conductivity, for example

  the separation of copper and lead or alumina

nium and lead.

  An electrodynamic process of separation is known

  of current conducting non-magnetic materials (US, A, 4248700), according to which a powdery material

  traveling is subject to the action of a magnetic field.

  that continuous, extended, heterogeneous, the material being moved at an angle to the magnetic lines of force

of the field.

  This method is implemented in a device (US, A, 4278700) which comprises a conveyor belt

  under which permanent polarity magnets are installed

  rised in opposition and arranged in parallel rows

  parallel to the axis of the conveyor belt.

  The method and device described above

  to separate only relatively

  which are current conductors. The period

  Magnetic magnets and the speed of movement of the conveyor belt do not allow the separation of particles of a small size. In addition, the magnetic field provided by the rows of permanent magnets is too weak and to obtain a deviatior, notable

  conductive particles of their trajectory, it is neces-

  to have a field of a large extent.

  However, a too large field reduces the efficiency of the electrodynamic separation device because of the large flows

dispersion.

  An electrodynamic process of separation is known

  tion of non-ferromagnetic current-conducting particles (FR, A, 2447754), in which a magnetic field

  is produced and a pulverulent material

  ter is brought perpendicular to the direction of the field. The field captures current conducting particles in matter by diverting them from their path and pulling them out of the flow of matter.

  to be treated and perpendicular to the direction of

  Vee. A device (FR, A, 2447754) for the application of this method comprises a conveyor belt and a linear induction motor which is arranged immediately under the belt so that the intensity of the formed field

  induction motor has an orien-

  perpendicular to the arrival center of the material.

  The method and the device for its implementation

  In accordance with the above-mentioned French patent, they have the same disadvantages as those of the aforementioned US patent. In particular, the particle size range

  to be sorted.Do not go below 10 mm in the

  because of the insufficient pace of the magnetic circuit.

  linear induction motor tick. The magnetic field

  progressive, like the field formed by permanent magnets

  according to the US, A, 4248700, provides only a weak

  current-conducting particles, which impli-

  that the use of an extensive magnetic field reducing the energy indices of the device, if we want to make sure

  a good efficiency of the separation.

  There is known a method of electrodynia separation

  non-ferromagnetic or current-conducting particles (FR, A, 2447228) in which a high-frequency magnetic field is formed, and a non-ferromagnetic powder material to be separated, which contains particulates, is introduced into the field; a different electrical conductivity. The flow of the material to be separated is brought into a plane perpendicular to the high frequency and high intensity gradient lines of force, the dispersions flows are reduced and it becomes possible to separate the smaller particles without being limited. by their size in the part'basse of the range of sizes to be treated. Thus, the disadvantages of the indicated methods and devices are eliminated here.

  higher for electrodynamic separation.

  However, the method and apparatus according to FR, A, 2447228 have a limitation with respect to the possibility of separating larger particles from a

  material to be treated. This is due to the fact that the elec-

  single-gradient tromagnet is generated by a

  closed magnetic cooking and that the extent of the field

  height of the flow of the material to be introduced.

  re is limited by the value of the air gap between

  polar noises of the magnetic circuit. For this reason, the largest dimension of the particles to be treated

  must not exceed half of the gap. For arrangements

  of the type described, this dimension can not

  pass 5 mm. We know, in fact, that the intensity of the field in the air gap between the polar expansions, so

  the magnetomotive force acting on the conductive particles

  electricity, is inversely proportional to the value of the gap at power three. That is why, by increasing the air gap for example twice, to obtain a magnetomotive force necessary

  to deflect the conductive particles from the electri-

  tricity, it is necessary to increase the intensity of the

  magnetic field. As a result, the increase in

  between the polar expansions of the magnetic circuit

  tick in order to raise the upper ceiling of the particle size to be treated leads to energetic expenditure

  so high that such an electromagnetic circuit

comes virtually unrealizable.

  Another factor preventing the increase of

  Part of the particles to be separated lies in the fact that at the same time as the size of the particles is increased, the friction force between them and the surface carrying them is increased; the magnetomotive force

  in-game may be insufficient to deflect

  of their initial trajectory. In addition, the method and the device mentioned above have a low separation efficiency because the arrival of the material to be treated takes place along the line of the maximum intensity of the high intensity gradient magnetic field and that the width of the layer of material to be introduced is limited by the extent of the

  field in the direction of the very narrow zone high gra-

  have intensity. In other words, the greater the intensity gradient of the field (which is advantageous when it is necessary to reduce the flow of dispersion and improve the efficiency of the separation), the greater the layer of matter.

  to introduce in this field must be narrow.

  The present invention relates to a method and a

  positive electrodynamic separation of non-particulate

  ferromagnetic electrically conductive using a magnetic field, where said field is shaped so

  to remove physical obstacles in the path of

  to be separated and to provide partial compensation

  friction forces between the conductive particles

  these electricity and the surface of their displacement as well as to increase the extent of the field in the direction of the width of the layer of material to move, which allows to increase the size of the particles to separate

  while improving the efficiency of the separation.

  The goal thus set is solved by the fact that

  electrodynamic separation process of non-particulate

  electrically conductive ferromagnets consisting in forming a high frequency electromagnetic field and

  to introduce, in this field, a pulverulent material with a sepa-

  having non-ferromagnetic particles of

  different electrical conductivity, the maximum intensity line

  male of this magnetic field being located in the plane of arrival of the material and the field having a high gradient

  of intensity in a direction perpendicular to the line of in-

  tensity in the plane of arrival of the material, is characterized in that said magnetic field further has a high intensity gradient perpendicular to the plane of arrival of the material and the line of maximum intensity of the field is

  angled with respect to the feed direction of the material.

  The goal is also achieved by the fact

  that an electrodynamic separation device of parti-

  non-ferromagnetic conductors of electricity of the type comprising an electromagnetic circuit and a

  medium to flat bearing surface to introduce a material

  to be separated in the field generated by the electrical circuit

  tromagnetic is characterized in that, according to the invention,

  the electromagnetic circuit comprises a single-turn linear inductor which is surrounded, at least over part of its length, with a magnetic core in the form of a U, in that the inductor is disoosed below the carrying surface of the means of transport of the material to

  separate so that the axis of the inductor is parallel

  is aligned with the plane of the bearing surface of the feed means of the

  material to be treated and forms an angle to the

feed rection of the material.

  In the method and the device according to

  the invention, the electromagnetic field is of the type

  two gradients, that is to say that it is formed in a

  free space which is not limited by the polar expansions of an electromagnetic circuit nor by other

  which may constitute an obstacle to the passage of

  its particles of a material to be separated through the magnetic field. The presence of a field intensity gradient

  in a direction perpendicular to the plane of introduction of the

  This material reveals a component of the electronic force

  dynamic acting in the same direction and offsetting,

  to a certain extent, the gravitational force of the

  which facilitates the separation of large

  conductive elements of electricity.

  Thanks to the formation of a magnetic field whose

  the axis of maximum intensity forms an angle with the direction

  introduction of the material, another component of

  the electrodynamic force arises, which acts on the

  conductive cules in the direction of the axis of maximum intensity and which deflects these particles, along this axis, the transport surface. Moreover, with such an orientation of the field relative to the feed direction of the material, it becomes possible to introduce a material to be separated into a wide layer, the maximum width "c" of such a layer being calculated according to the formula c =. sin, o

  is the range of the maximum intensity line

  male of the field and is the angle between this line and the direction

supplying material.

  As a result, the efficiency of the separation

Liore.

  According to the method of the invention for separating

  In the electrodynamic mode, the line of the greatest intensity of the field is advantageously located at an angle of 30 to 45 with respect to the direction of arrival of the material; according to

  an advantageous embodiment of the separating device

  electrodynamic axis, the axis of the inductor forms an angle of

  - 45 with the direction of arrival of the material.

  When the angle formed between the line of the most

  the intensity of the field and the direction of arrival of the

  The material is at values included in the age indicated,

  energy consumption is minimal although the efficiency

  the city of separation is always high.

  According to an advantageous embodiment of the electrodynamic separation device, the core of the

  electromagnetic circuit is in a transverse section

  dirty in the form of a folium of Descartes which is truncated from

side of the nodal point.

  Avect such a realization of the nucleus, the field

  which is formed by the electromagnetic circuit

  gnetic has a maximum intensity gradient which helps to increase the efficiency of the separation. The invention will be better understood and other purposes, details and advantages thereof will become more apparent in the

  light of the following explanatory description of a

  embodiment given solely by way of nonlimiting example, with references to the appended nonlimiting drawings in which: - Figure 1 shows the principle on which is

  based on the electrodynamic separation process of

  non-ferromagnetic conducting electrically conductive cells according to the invention;

  - Figure 2 shows curves showing the relationship

  between the reduced power required to form an electromagnetic field and the orientation of an angle formed between the maximum field strength line and the feed direction of the material to be separated in the method of the invention;

  FIG. 3 shows a device for realizing

  the electrodynamic separation process according to the present invention; FIG. 4 is a plan view of the device of FIG. 3; and FIG. 5 shows, in cross-section, the core of the electromagnetic circuit for the devices

  putting the electrodynamic separation process of the

  tion and a diagram of. intensity variations.

  The electrodynamic separation process of

  Non-ferromagnetic electrically conductive particles according to the present invention consists of the following. A non-ferromagnetic powder material in the form of a mixture containing particles having different electrical conductivity values, for example particles 1

  (Figure 1) non-ferrous or noble metals and

  2 of non-electrically conductive materials is brought into a single layer, in a plane 3 in a high frequency and high intensity gradient electromagnetic field and at a velocity V. The direction of introduction of the material is shown by the arrow in Figure 1. The electromagnetic field is formed so that its line

  4 maximum intensity is in the introduction plan 3.

  material and forms an angle X with the direction of this introduction. To better understand the principle of electrodynamic separation according to the invention, it

  the rectangular coordinate system should be

  res, where the X and Y axes are in the plane 3 of arrival of the

  material, the Y axis merges with line 4 of the intensi-

  maximum of the field while the Z axis is perpendicular

  to the plane 3 of arrival of the material. The components of the intensity of the field along these axes are referenced

  respectively by H, H and H. The electromagnetic field

X Y Z

  that is formed so as to have two gradients of inten-

  sity, which means that its intensity varies in two

  perpendicular directions: towards the X axis and direc-

  Z axis. In the direction of the Y axis, the intensity gradient

  sity is equal to zero and the field extent along the Y axis must correspond to the width of the layer of material to be introduced into the field. It should be noted that the field

  electromagnetic energy is formed in a free space that does not

  there is no limit to the maximum size of the

  particles to separate. In practice, this maximum size is limited by the energy consumption required for

formation of the magnetic field.

  Introduced into the magnetic field, the

  non-electrically conductive cells 2 which are

  naked in the material to be separated are not influenced by this field and cross the line 4 of maximum intensity of the field without deviating from their trajectory. On the other hand, when the particles of non-ferromagnetic metals 1 arrive

  in the electromagnetic field, tidal currents

  are induced in these particles, which are proportionally

  their dimensions and the electrical conductivity of the material of which they are made. The frequency of the electromagnetic field is chosen so that the pronounced skin effect of the particles 1 is ensured, that is to say so as to have an effective depth of penetration of the alternating current in the material of the electromagnetic fields.

  particles 1 3 to 6 times the average

  none of these. To satisfy this condition, the frequency f of the electromagnetic field must satisfy the relationship f d2 10 Hz, in which d: average particle size of metals 1 in the prescribed range of sizes, m; : resistivity of the material of the particles 1,

Ohm by m.

  Vortex currents flowing along

  particle surfaces 1 in turn generate

  of these particles, electromagnetic fields which, as a result of the interaction with the electromagnetic field of departure inducing these vortex currents, show an electrodynamic force F which acts on the particles 1 in a direction which is perpendicular to the line 4 d the maximum intensity of the field and forms an angle with the plane 3 of introduction of the material, this angle being related to the values of the field gradients in the direction of X and Z. The electrodynamic force F tends

  to remove the particles of metals I in the direction of de-

  growth of the intensity of the magnetic field; the more the particles 1 are close to the line of maximum intensity of the field, the more important is the action of this force. The electrodynamic force F has two components: a component F2 directed perpendicularly to the plane 3 of introduction of the material and a component Fx acting in the plane 3 and which is directed perpendicularly to the line 4 of maximum intensity of the field. The component F tends to lift the particles 1 above the plane 3 z

  and thus partially offsets gravitation in

  the friction forces between the particles

  i and the surface of their displacement.

  i0 Because line 4 of maximum intensity of

  field is oriented to form an angle

  the direction of introduction of the material, the

  The F force of the electrodynamic force F can in turn be divided into two components: a component Fi which acts in the opposite direction of the direction of arrival of the material and a component F2 acting along the line 4 of intensity

  maximum of the field. F1 force exerts a braking action

  swimming on the particles, this force being equal in

  but acting contrary to the

  health of inertia of the static friction limit force for the particles 1. The force F2 exceeds, in size,

  the tangential component of the friction force limit

  particle static and has a direction opposite to the direction of this tangential component. This force F2 deflects the metal particles 1 from their starting trajectory

  and extracts the particles 1 from the material being separated

  along line 4 of maximum field strength. So the H value of the field strength can

  be such as to ensure the creation of electronic forces

  dynamic F and F that are important enough for x z

  compensate for the friction forces of the metal particles

  1, of a given size range, against the surface

  this of their displacement and to extract these particles 1 from the material to be treated at a prescribed angle i. That said, the value of the force F2 which deflects the particles 1 from

  their departure trajectory is obtained according to the expression

following statement: F2 = KHx grad Hx Cos

  o K is a coefficient proportional to the

  electrical resistance of the material of the particles 1, their volume and weight, and

  H is the intensity component of the field followed by

  x the X axis for the determined position of a particle. Since, on the action of the force F, the friction forces between the particles 1 and the surface of their displacement decrease, the two forces F1 and F2 can be reduced by a corresponding value, so the

  energy consumption leading to the separation of

  in a field with two intensity gradients, which is formed in accordance with the method according to the invention, becomes

  lower than the energy consumption in a magnetic field

  tick with unique intensity gradient. On the other hand, for the same power consumption required for the formation of the field, a field with two intensity gradients makes it possible to

  separate larger particles from non-metals

ferromagnetic.

  The speed V of introduction of the material is chosen

  based on the specific technological requirements

  the quality and performance of the separation process.

  The value of the orientation angle 4 of the line

  4 of maximum intensity of the field relative to the direction

  the material to be treated is chosen on the basis of the need to ensure optimum

  metal particles 1, the material to be treated according to the

  4. For this purpose, the force F2 must be greater than the force F1, that is to say that

F2 / F1 = Ctg> 1 and + 45.

  If we assume that, in Figure 1, the angle is calculated clockwise from the direction

  of introduction of the material, the particles will be ex-

  treated to the right in the direction of delivery of the

  with O <+450, they will be extracted to the left with i <-45. When the force F2 is smaller than the force F1 (δ> 45), the metal particles 1 do not strictly follow their trajectory along the line 4 and the rate of shrinkage of the magnetic field decreases. As a result, the particles accumulate in the field action zone and prevent the material to be treated from penetrating.

  in this field, thus reducing the effectiveness of the separa-

  tion. The principle according to which the angle i is chosen is illustrated by FIG. 2 where the relations between the coefficient ú of non-particle extraction are given.

  ferromagnetic conductors of electricity and the

  reduced capacity necessary for the formation of an electric field.

  tromagnetic capable of separating these particles, on the one hand, and the angle cX on the other hand. The reduced power here indicates a ratio of the power P1 necessary for the formation of a field whose line of maximum intensity is of length y and forms an angle i with respect to the direction of introduction of the material, the power Pc c which is necessary for the formation of a similar field

  with a line of maximum intensity arranged perpendicular

  stretch to the direction of introduction of the material and

  whose length is c = y sinKi. The curves represent

  shown in Figure 2 are established by experimental methods.

  As shown in Figure 2, the place of the values of the angle i ranging from 30 to 45 is assumed to be optimal.

  compared to the coefficient _. characterizing the effectiveness

  quoted from the separation, and vis-à-vis the energy consumption that is necessary for the formation of a magnetic field. In the case where we have <300, the coefficient decreases significantly while the energy consumed

  to form a magnetic field soars.

  The device for carrying out the above-described method of electrodynamic separation according to the invention comprises an electromagnetic circuit with a single-turn linear inductor 5 which can be seen in FIG. 3, having a core 6, a means flat transport surface for introducing the material to be separated in the field generated by the electromagnetic circuit,

  a loading hopper 7, a receptacle 8 of the particles

  the conductors 5, for example, metal, and a receiver

  tackle 9 to collect non-conductive particles 2 electricity. In the example described here of embodiment of the invention, the means for the introduction of a material to be separated is a conveyor 10, but it can for example be presented as an inclined surface made of a non-magnetic material, along which material to be separated moves under the action of gravitational forces

* or by vibrating the moving surface.

  The inductor 5 is arranged under the band of the trans-

  10 in the immediate vicinity of the latter so that the longitudinal axis 11 of the inductor 5 is parallel to the surface of the conveyor belt 10. Since the inductor 5 is a linear inductor that is that is to say that it has the shape of a single turn extended in one direction, the axis 11 of the inductor 5 here indicates the axis

  rectilinear portion which serves to form the elec-

  tromagnétique. Above the conveyor belt 10, upstream of the inductor 5 (in the conveying direction of the conveyor) is arranged the loading hopper 7 while the receptacles and 9 are located lower than the strip 10, indeed the receptacle B for the particles

  conductors is located near the edge of the trans-

  carrier o is the end of the core 6, and the receptacle 9 for the non-conductive particles of electricity

  is disposed near the end of the conveyor 10. The

  in the form of a hollow conductor of recess section

  tangular which is inserted into the U-shaped slot, for example, rectangular, of the core 6. The open side of the inductor 5, which is not surrounded by the core 6, is oriented towards the conveyor belt 10. The closed volume 12 of the inductor 5 serves to receive a refrigerant. The inductor 5 is supplied with high frequency current by a generator 13 which can be seen in FIG. 4. Pipes 14 communicating with the inside 12 of the inductor 5 serve to introduce and evacuate the cooling fluid. As can be seen in Figure 4, the axis 11 of the inductor 5 forms an angle with the longitudinal axis of the conveyor 10 and therefore the direction of introduction of the material to be separated. For the reasons

  presented above, when describing the process

  of electrodynamic separation according to the invention, the advantageous values of the angle are between

  and 45-.

  In the electromagnetic circuit shown in Figure 4, the core 6 surrounds the inductor 5 on one of its rectilinear portions along the entire width of the conveyor belt. In this case, the device ensures a single separation zone whose length is equal to the length of the core 6 and whose width h is equal to

  the width of the work surface. However, the inductor 5 can be embraced by the nucleus on its two por-

  rectilinear, in which case two separation zones are formed which are parallel to each other, which may be desirable to improve the efficiency of the separation. The second straight portion of the inductor

  is not surrounded by the nucleus can be arranged in a

  arbitrary in relation to the transport plan.

  In one embodiment of the compliant device

  to the invention, to the opposition of the mode represented in the

  1, the core of the inductor 5 does not "cover" the conveyor belt 10 over its entire width. that is to say, he

  It does not reach the edges of the strip.

  According to another embodiment of the invention

  a core 15, as can be seen in Figure 5, is in cross section as a curve called "folium Descartes" truncated on the side of its nodal point 16. The notch receiving the inductor 5 is formed of the side of the flat surface of the core 15. Such a shape of the core makes it possible to form an electromagnetic field having minimal deformations due to the end effect and with

  maximum intensity gradients in the area of the

  In order to increase the field gradients, the width h of the useful surface of the core 15

  should be as narrow as possible from the point of view of

  me thermal. The core 15 is provided with channels 17 for the

  circulation of the refrigerant. Channels. of cooling

  dissement can also be expected in the nucleus 6

  of Figure 3, if necessary.

  The electrodynamic separation device of the invention operates as follows. When the high-frequency current travels through the inductor 5 of FIG. 4, in the space above the core 6, an electromagnetic field with two gradients whose area of action,

  in the plane of the conveyor belt 10, is determined

  born by the length t and the width b of the core 6. The electromagnetic field has a maximum intensity

  towards the axis 11 of the inductor 5 (the Y axis)

  the entire length of the core 6, which suddenly decreases in the direction perpendicular to the axis 11 in the plane of the belt of the conveyor 10 (along the X axis) and in a

  direction perpendicular to the plane of the trans-

  carrier 10 (along the Z axis which is directed perpendicularly

  the stretch in the drawing of Figure 4).

  Variation of direction, with respect to the above-indicated meanings, of the intensity H of the magnetic field produced by the electromagnetic circuit having a ncvau in cross section such as a folium of

  Descartes truncated, are shown in Figure 5 which represents

  three intensity curves 18, 19 and 20 in three

1 1 1

  parallel planes 18, 19 and 20 respectively each spaced apart by a different distance from the working surface of the core 15. It should be noted that in the direction of the Y axis (that is to say along the length of the core )

the intensity of the field does not vary.

  The hopper 7 introduces, in a single layer, a non-ferromagnetic powder material containing metal particles 1 and particles 2 of materials

  non-conductive electricity or materials of

  Electrical conductivity on the conveyor belt 10. The material to be treated first arrives in the separation zone which is above the core 6 and which is

  characterized by the largest field gradients, the over-

  face of the separation zone being equal to Ad.h. By the-

  non-conductive particles 2 are transpor-

  conveyed through this separation zone to be collected in the receptacle 9. The metal particles 1 which are introduced into the

  separation zone are subject to an electrodyna-

  nomic. The decomposition of the electrodynamic force into

  components and the action of each component on the

  conductive particles of electricity have been described

  above when describing the method of the invention

  and are illustrated in FIG. 1. The component F2 of the electrodynamic force acting on the particles 1 in the direction of the line of the greatest intensity of the field, along the axis 11 of the inductor 5, ensures the displacement of the particles 1 in this direction and their removal from the surface of the conveyor belt 10

in the receptacle 8.

  In case the kernel does not reach the edges

  of the conveyor belt 10, the metallic particles

  1 move along the axis 11 of the inductor 5 to the zone of the edge of the strip under which there is no

  kernel and transport more closely parallel to the

  The receptacle 8 for the conductive particles is in this case disposed at the end of the conveyor 10 at a suitable distance from the receptacle 9 of the non-conductive particles.

  Although the method and apparatus of the invention

  have been described in the case where electrically conductive particles (metallic) are separated

  of non-conductive particles, it is obvious that the invention

  can be used to separate

  electricity producers of materials having different values of electrical conductivity, for

  copper and lead. For this purpose, an elec-

  tromagnetic such that it ensures a departure of the copper particles from their starting trajectory without the lead particles having a conductivity

  significantly less change of trajectory.

  Below are summarized the results obtained

  during the practical application of the process according to the invention

tion.

Example 1

  With the aid of a single-turn linear inductor, a two-gradient electromagnetic field with a maximum intensity of 0.1 to 0.3 T and a frequency of 10 kHz was formed. The transporter driven at a speed of m / min introduced, in this field, fragmented cable waste containing the following materials: - aluminum: 81% - lead: 16%

- cable insulation: 3%.

  The particle size was 2.5 and

  mm, the efficiency of the device being 0.6 t / h. The an-

  between the axis of the inductor and the direction of

  the material was 450. The extraction rate of aluminum

minium reached 98.6 to 99.2% o.

Example 2

  Using a single-turn linear inductor, a two-gradient electromagnetic field with a maximum intensity of 0.1 to 0.3 T and a frequency of 440 kHz was formed. The carrier introduced in this field,

  a speed of 30 m / min, the waste of radio

  containing the following materials: - aluminum, brass and copper: 60% - ceramic and rubber: 40% The particle size was between

  1 and 5 mm, the efficiency of the device was 0.3 t / h.

  The angle formed between the axis of the inductor and the direction

  introduction of the material was 45. We got

  an extraction rate of the indicated metals of 91 to 92G%.

Claims (5)

R E V E N D I C AT IO N S ===========================   1. A process for the electrodynamic separation of non-ferromagnetic electrically conductive particles of the type consisting in forming an electromagnetic field at   high frequency and to introduce, in this field, a   Pulverulent material to be separated containing electromagnetic particles having different conductivity values   the maximum intensity of the elec-   tromagnetic contained in an introduction plan of the   material and the field with a high gradient of inten-   in the direction perpendicular to that line of inten-   maximum capacity in said plane of introduction of the material,   characterized in that the electromagnetic field has   to be a high intensity gradient in the direction   pendicular to said plane of introduction of the material and in that the line of maximum intensity of the field is arranged so as to form an angle with respect to the direction of introduction of the material.   2. Method according to claim 1, characterized   in that the maximum intensity line of the field is dis-   placed at an angle of 30 to 450 with the   direction of introduction of the material.   3. Apparatus for carrying out the method according to claim 1, of the type comprising an electromagnetic circuit and a flat bearing surface means for introducing a material to be treated in the field created by the electromagnetic circuit, characterized in that that the electromagnetic circuit has a. single-turn linear inductor (5) which is surrounded, at least over part of its length, by a U-shaped core (6), in that the inductor (5) is arranged below the surface   bearing means (10) for introducing the separating material   make sure that the axis (11) of the inductor (5) is parallel   aligns with the plane of the bearing surface of the means (10) for introducing the material to be separated and forms an angle   compared to this introductory direction.   4. Device according to claim 3, characterized   in that the axis (11) of the inductor (5) forms an angle of 30 to 450 with the direction of the introduction of the material.   5. Device according to any one of the   3 or 4, characterized in that the core (15) of the electromagnetic circuit has, in cross section, the form of a folium of Descartes truncated on the side of the point nodal (16).