Electric crusher with staged discharges for rock material

Abstract

The invention relates to a grinder (1) comprising a grinding chamber, at least one first positioning element (21) made of an electrically insulating material, at least one second positioning element (22) made of an electrically insulating material and whose dimensions are smaller than the dimensions of a first positioning element (21) to form a second filtering space, and at least one pair of electrodes comprising a first electrode (10) and a second electrode (31) arranged opposite each other on either side of the second filtering space. Figure 4

Description

Title of the invention: Electric crusher with staged discharges for rock material. Technical field

[0001] The present invention relates to the field of rock crushing and more particularly concerns a rock material crusher and a rock material crushing process by electrical discharge. Previous technique

[0002] It is known to crush rock to extract metals such as, for example, copper. Such extraction can be carried out purely mechanically or, more efficiently, by high-voltage electrical discharges.

[0003] In mechanical solutions, it is necessary to completely crush the rock material to transform it into rock powder and to be able to extract the metal, which can prove to be particularly long and require a very large amount of energy.

[0004] In electrical solutions, the discharges break the rock into smaller and smaller pieces until it is possible to extract the metal.

[0005] Thus, for example, patent application EP3261768A1 describes a device comprising electrodes arranged above a conveyor belt. However, such a solution does not allow the rocks to be sorted according to their size, and the pieces must then be passed over the belt several times to obtain sufficient particle size, which can prove to be time-consuming and costly, particularly in terms of energy.

[0006] Patent application WO99 / 03588 describes a gravity-guided grinding process which may, however, again require significant energy and considerable time.

[0007] Other solutions exist, for example described in documents JP11033430, EP2691180A1, DE102014008989, WO20200120437, but they do not allow the rock to be crushed efficiently.

[0008] The solution described in patent application GB2421203 describes an interesting method for crushing increasingly smaller rocks, but it does have several drawbacks. Due to the oblique configuration of the electrodes, at approximately 45°, pieces of rock that cannot pass through the gap between the electrodes of a pair of electrodes become stuck on the electrodes but may not reach the gap. Also, during an electrical discharge, the current will take the shortest path in the vacuum under a piece of rock, which will prevent it from being fragmented and will jam the device, thus requiring operator intervention to clean the crusher.

[0009] US patent application US 2021 / 069724 A1 describes a rock crusher comprising a crushing chamber, a pair of electrodes, and a generator. The crusher filters the material according to its size but does not fragment all the rock elements, which can again clog the device, thus requiring operator intervention to clean the crusher.

[0010] There is therefore a need for a simple and effective solution to remedy at least some of these drawbacks. Description of the invention

[0011] To this end, the invention first relates to a rock crusher using electrical discharge, said crusher comprising:

[0012] - a grinding chamber comprising at least one side wall defining a internal space, an upper face through which the rock material is introduced and a lower face through which the crushed rock material is collected,

[0013] - at least a first positioning element, made of a material electrically insulating, mounted in the internal space at the level of the lower face of the chamber and positioned so as to form a first filtering space allowing crushed rock material to be evacuated through the lower face of the chamber, said at least a first positioning element comprising on its upper surface, along the first filtering space, a support portion configured to support rock material,

[0014] - at least a second positioning element, made of a material electrically insulating and whose dimensions are smaller than the dimensions of a first positioning element, each second positioning element having a free edge and being mounted in the internal space above a first positioning element such that said free edge delimits a second filtering space extending above the support portion of the first positioning element located below and down to the first filtering space, the free edge of the second positioning element and the support portion of the first positioning element located below thus allowing rock material to be positioned in said second filtering space,

[0015] - at least one pair of electrodes comprising a first electrode and a second electrodes, arranged facing each other on either side of the second filtering space,

[0016] - at least one generator configured to apply a voltage between the first electrode and at least a second electrode so as to cause an electrical discharge to grind the rock material elements positioned in the second filter space and thus allow at least some of the ground rock material to pass into the first filter space to be collected.

[0017] The electric crusher with staged discharges according to the invention makes it possible to crush rock efficiently thanks to positioning elements that allow the rock material to be positioned in the filter spaces according to their size between the first and second electrodes of an electrode pair. The use of several increasingly finer filter spaces makes it possible to obtain increasingly finer crushed material from top to bottom, until the desired size is reached at the outlet through the first filter space.

[0018] According to one aspect of the invention, the first electrode and the second electrode of a pair of electrodes are configured to generate an electric arc in the filter space around which they are placed when a voltage is applied between said first electrode and said second electrode.

[0019] In one embodiment, at least one first electrode is an anode and at least one second electrode is a cathode.

[0020] In another embodiment, at least one first electrode is a cathode and at least one second electrode is an anode.

[0021] Advantageously, the grinder comprises more than two positioning elements, each made of an electrically insulating material and stacked one on top of the other, the dimensions of a higher positioning element being smaller than the dimensions of the immediately lower positioning element so as to form a filtering space with a width greater than the width of at least one filtering space formed by the immediately lower positioning element and opening onto said filtering space formed by the immediately lower positioning element.

[0022] In one embodiment, the electrodes, in particular the second electrode(s), are mounted between two positioning elements in a space called "inter-element" by extending radially in the internal space.

[0023] In another embodiment, at least part of the electrodes, in particular the second electrode(s), is mounted in a positioning element by extending radially in the internal space.

[0024] Advantageously, the at least second electrode may be a single all-metallic electrode, for example in the form of a disc, or comprise an electrical insulator comprising one or more metallic electrodes.

[0025] Alternatively or in addition, the at least one second electrode may comprise several electrodes, each having an elongated shape and extending radially while being equally distributed around the longitudinal axis of the stack.

[0026] In one embodiment, at least one first electrode and at least one second electrode are linear, for example in the form of a rod.

[0027] In one embodiment, the grinder comprises a single first electrode of cylindrical shape, preferably of circular or polygonal cross-section (for example square or hexagonal).

[0028] In one embodiment, the positioning elements are mounted around the first electrode and the filtering spaces are formed against the outer wall of said first electrode.

[0029] Advantageously, in this embodiment, the positioning elements are cylindrical in shape and arranged coaxially with the first electrode.

[0030] Advantageously, still in this embodiment, the crusher includes a truncated conical element pierced in its center, mounted in the upper part of the chamber in order to direct the rock material introduced into the chamber towards the filtering spaces.

[0031] In another embodiment, the positioning elements are mounted inside the first electrode and the filtering spaces are formed against the inner wall of said first electrode.

[0032] Advantageously, in this embodiment, the positioning elements are cylindrical in shape and arranged coaxially with the first electrode.

[0033] Advantageously, still in this embodiment, the crusher includes a conical element mounted on the highest positioning element in order to direct the rock material introduced into the chamber towards the filtering spaces.

[0034] Advantageously, still in this embodiment, the side wall of the chamber comprises the first electrode or constitutes the first electrode.

[0035] In another embodiment, at least one first electrode and at least one second electrode are linear, for example in the form of a metal rod.

[0036] Advantageously, in this embodiment, the positioning elements are rectangular in shape.

[0037] Advantageously, the crusher includes in its upper part at least one fluid inlet configured to deliver a flow of fluid to convey the pieces of rock material through successive filter spaces according to their size to crush them and then discharge them.

[0038] Preferably, the width of each filter space is adapted to the size of the rocks to be crushed so as to ensure the positioning of the rocks between the electrodes before crushing and the evacuation of the rocks after crushing according to the desired final size.

[0039] Preferably, the width of the first filter space is less than 5 mm, preferably even less than 3 mm, preferably even less than 2 mm, for example to recover fine rock powder which may, for example, contain a large proportion of ore.

[0040] Advantageously, the portions of material delimiting a filtering space can extend radially or axially or form a bend or a slope, for example at 45°, to filter the pieces of rock.

[0041] In one embodiment, the filtering space or spaces of a stage are formed in the positioning element of said stage or in an electrically insulating support inserted in a dedicated space.

[0042] Preferably, the crusher includes a collector fixed under the bottom of the crusher so that the first filter space opens into said collector.

[0043] In one embodiment, the crusher further includes at least one presence sensor configured to detect the presence of rock material between the first electrode and at least one second electrode.

[0044] In one embodiment, the grinder is configured to automatically control a series of electrical discharges between at least one pair of electrodes.

[0045] Advantageously, the grinder being configured to automatically control a series of electrical discharges between at least one pair of electrodes at a frequency between one and a few hundred Hertz, up to 1000 Hertz.

[0046] The invention also relates to a method for crushing rock material by electrical discharge, said method, implemented by a crusher as described above arranged vertically in the operating position, comprising the steps of:

[0047] - introduction of rock material through the upper face of the chamber,

[0048] - positioning of rock material at least in the filtering space defined by the highest positioning element between the electrodes of at least one pair of electrodes, said rock material being supported by the support portion of the positioning element located immediately below the highest positioning element,

[0049] - triggering at least one electric discharge at each stage, preferably a series of discharges, from a voltage supplied by at least one generator, in order to crush the rocky material positioned between the electrodes of each stage,

[0050] - conveying increasingly finer rock material through the spaces of successive filtering from top to bottom,

[0051] - evacuation of the crushed material through the first filtering space, of preference towards a collector fixed under the lower face of the chamber.

[0052] Advantageously, the process includes introducing a fluid, for example water, through the top face of the chamber during grinding in order to circulate the pieces of rock material easily through the filter spaces.

[0053] Advantageously, the method includes a step of detecting rock material by a detection sensor in at least one of the filter spaces between the first electrode and a second electrode and applying a voltage across the terminals of the first electrode and said second electrode in order to trigger at least one grinding discharge. Brief description of the drawings

[0054] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

[0055] [Fig-1] Fig.1 schematically illustrates in perspective a form of realization of the crusher according to the invention.

[0056] [Fig.2] The [Fig.2] is a partial perspective top view of the crusher of the [Fig.1] without a cover.

[0057] [Fig.3] The [Fig.3] is a partial perspective view of the grinder of the [Fig.1] without the cover, side wall and first electrode.

[0058] [Fig.4] The [Fig.4] is a longitudinal cross-sectional view of the crusher of the [Fig.1].

[0059] [Fig. 5] Fig. 5 is a schematic longitudinal cross-sectional view of a first example of a first type of arrangement, with central filtration, of the crusher 1 according to the invention.

[0060] [Fig.6] The [Fig.6] is a schematic cross-sectional view of a circular shape of the crusher of the [Fig.5].

[0061] [Fig.7] The [Fig.7] is a schematic cross-sectional view of a square shape of the crusher of the [Fig.5].

[0062] [Fig.8] The [Fig.8] is a schematic longitudinal sectional view of a second example of the first type of arrangement, with central filtering, of the mill 1 according to the invention.

[0063] [Fig.9] The [Fig.9] is a schematic longitudinal sectional view of a third example of the first type of arrangement, with central filtering, of the mill 1 according to the invention.

[0064] [Fig. 10] The [Fig. 10] is a schematic longitudinal sectional view of a first example of a second type of arrangement, with peripheral filtering, of the mill 1 according to the invention.

[0065] [Fig. 11] The [Fig. 11] is a schematic longitudinal sectional view of a second example of the second type of arrangement, with peripheral filtering, of the mill 1 according to the invention.

[0066] [Fig. 12] The [Fig. 12] is a schematic longitudinal sectional view of a third example of the second type of arrangement, with peripheral filtering, of the mill 1 according to the invention.

[0067] [Fig. 13] The [Fig. 13] is a schematic longitudinal sectional view of an example of a third type of arrangement, with linear filtering, of the mill 1 according to the invention.

[0068] [Fig. 14] The [Fig. 14] is an enlarged schematic longitudinal sectional view of a bent filter space shape.

[0069] [Fig. 15] The [Fig. 15] is an enlarged schematic longitudinal sectional view of an inclined filter space shape.

[0070] [Fig. 16] The [Fig. 16] is a schematic perspective view of a positioning element having orifices at the level of its support portion, said orifices forming a plurality of filtering spaces.

[0071] [Fig. 17] The [Fig. 17] schematically illustrates one embodiment of the process according to the invention. Description of the implementation methods

[0072] Figures 1 to 4 show an example of a crusher 1 according to the invention and Figures 5 to 13 show different examples of internal arrangement of the crusher 1 according to the invention.

[0073] Example of figures 1 to 4

[0074] With reference to [Fig.1], the crusher 1 comprises a crushing chamber 2 provided with a side wall 3, a cover 4, a bottom 5.

[0075] With reference to [Fig.2], the side wall 3 of the chamber 2 is cylindrical with a circular cross-section and defines an internal space 2A in which a first cylindrical electrode 10, also with a circular cross-section, is placed.

[0076] Chamber 2 comprises an upper face 2B and an lower face 2C ([Fig.3]).

[0077] With further reference to [Fig. 1], the side wall 3 has at its upper edge a circular rim 3A allowing the cover 4 to be fixed using screws.

[0078] The cover 4 has a vertical inlet conduit 4A allowing pieces of rock material to be inserted into the chamber 2.

[0079] With reference to figures 2 and 3, the crusher 1 comprises a conical element 6.

[0080] With reference to Figures 3 and 4, the crusher 1 comprises a first element of positioning 21, a second positioning element 22, a second electrode 31, a generator (not visible in the example of figures 1 to 4 but represented in the arrangement examples given below with reference 40), and a rock powder collector 50.

[0081] The first positioning element 21 is circular in shape, is mounted on the bottom 5 and is made of an electrically insulating material.

[0082] With reference to [Fig.4], the first positioning element 21 has radial dimensions smaller than the diameter of the first electrode so as to form a first circular EPI filtering space.

[0083] The first EPI filter space allows the crushed material to be evacuated through the bottom 5 of the crusher 1 towards the collector 50.

[0084] The second positioning element 22 is made of an electrically insulating material and also has a cylindrical shape with a circular cross-section and a radius smaller than that of the first positioning element 21 so that a portion of the upper surface of the first positioning element 21, designated "support portion" PP1, remains apparent and accessible to the pieces of rock that are inserted into the crusher 1.

[0085] The second electrode 31 has the form of a metallic disc with a radius substantially equal to the radius of the second positioning element 22 and is mounted coaxially and integrated into the second positioning element 22 so as to be protected from rock falling into the second filter space EP2.

[0086] The free edge 31A of the second electrode 31 is thus projected opposite the first electrode 10. The space formed between the first electrode 10 and the second electrode 31, above the support portion PP1, is designated the second filter space EP2. The second filter space EP2 is in fluidic communication with the first filter space EPI to allow the passage of the crushed rock material, according to its size.

[0087] The generator makes it possible to apply a voltage between the first electrode 10 and the second electrode 31 in order to break and grind the pieces of rock material positioned on the support portion PP1 between the first electrode 10 and the second electrode 31. Once ground sufficiently finely, the rock is evacuated through the first space EPI.

[0088] Examples of arrangement of figures 5 to 13

[0089] In the examples in Figures 5 to 13, the crusher 1 comprises four positioning elements 21, 22, 23, 24 but could, in other embodiments, comprise two, three or more than four.

[0090] Similarly, the crusher 1 includes three second electrodes 31, 32, 33 but this number could be different in another embodiment, with at least one second electrode 31. According to one aspect of the invention, there is at least one second electrode 31, 32, 33 per stage from the second positioning element 21 in order to crush rocks of different sizes at each stage, increasingly finely.

[0091] Each positioning element 21, 22, 23, 24 is made of an electrically insulating material and has a cylindrical shape with a circular cross-section.

[0092] In the arrangement examples of figures 5 to 13, each pair of consecutive positioning elements 21, 22, 23, 24 is separated by a so-called "inter-element" space in which a second electrode 31, 32, 33 is mounted. In other words, the second electrodes are mounted between the positioning elements 21, 22, 23, 24.

[0093] In the examples in Figures 5 to 13, each second electrode 31, 32, 33 has a shape identical to that of the cross-section of the cylindrical chamber 2 (circular, square, polygonal, etc.) and can thus, for example, be in the form of a disk, a square or a polygon with a hole in its center and arranged coaxially in the chamber 2.

[0094] The first electrode 10 and each second electrode 31, 32, 33 form three pairs of electrodes, each supplied by the same generator 40 or by a dedicated generator 40, preferably mounted inside the chamber 2.

[0095] The generator 40 is configured to deliver a voltage between the electrodes of each pair of electrodes so as to cause an electrical discharge between said electrodes in the corresponding EPI, EP2, EP3, EP4 filtering space.

[0096] The voltage delivered by the generator 40 is adapted to provide a discharge capable of crushing the rock material elements positioned between each first electrode 10 and second electrode 31, 32, 33 of each electrode pair. For example, the voltage can be several hundred kilovolts or several gigavolts.

[0097] First type of arrangement (figures 5 to 9): central filtering

[0098] In this type of arrangement, the first electrode 10 is central and is preferably an anode. The first electrode 10 is cylindrical and can be a solid cylinder (Figures 5 to 8) or a hollow cylinder ([Fig. 9]) in which at least one generator 40 is mounted.

[0099] The positioning elements 21, 22, 23, 24 are stacked coaxially around the first cylindrical electrode 10 along the longitudinal axis of said first electrode 10 on a base 2. The diameter of the positioning elements 21, 22, 23, 24 decrease from bottom to top.

[0100] The cross-section of each positioning element 21, 22, 23, 24 has a shape identical to the cross-section of the first cylindrical electrode 10, but with larger dimensions so as to allow the positioning element 21, 22, 23, 24 to be placed around the first electrode 10, radially forming a filtering space EP1, EP2, EP3, EP4 between the positioning element 21, 22, 23, 24 and the first electrode 10. Each space of The EPI, EP2, EP3, EP4 filtering thus formed allows the reception of rock material of dimensions less than its width.

[0101] Thus, in the example of [Fig.5]:

[0102] - the first positioning element 21 is arranged around the first electrode 10 of the first electrode 10, forming a first EPI filtering space with the first electrode 10,

[0103] - the second positioning element 22 is arranged above the first positioning element 21 around the first electrode 10 radially forming a second filter space EP2 with the first electrode 10, the width of said second filter space EP2 being greater than the width of the first filter space EPI and the first support portion PP1 of the first positioning element 21 being configured to support the rock material elements located in said second filter space EP2,

[0104] - the third positioning element 23 is arranged above the second positioning element 22 around the first electrode 10 radially forming a third filter space EP3 with the first electrode 10, the width of said third filter space EP3 being greater than the width of the second filter space EP2 and the second support portion PP2 of the second positioning element 22 being configured to support the rock material elements located in said third filter space EP3,

[0105] - the fourth positioning element 24 is arranged above the third positioning element 23 around the first electrode 10 radially forming a fourth filter space EP4 with the first electrode 10, the width of said fourth filter space EP4 being greater than the width of the third filter space EPI and the third support portion PP3 of the third positioning element 23 being configured to support the rock material elements located in said fourth filter space EP4.

[0106] A truncated cone-shaped directional element (not shown) can be positioned coaxially above the stack of positioning elements 21, 22, 23, 24 with the smallest diameter facing down flush with the fourth filter space EP4 in order to guide the pieces of rock introduced into the crusher 1 directly towards the fourth filter space EP4.

[0107] Figures 6 and 7 show two examples of the shape of the crusher 1 (cross-sectional views). In the example in [Fig. 6], the positioning elements 21, 22, 23, 24, the filter spaces EPI, EP2, EP3, EP4, the first electrode 10 and the second electrodes 31, 32, 33 are circular. In the example in [Fig. 7], the positioning elements 21, 22, 23, 24, the filter spaces EPI, EP2, EP3, EP4, the first electrode 10 and the second electrodes 31, 32, 33 are square in shape.

[0108] In the example of [Fig.8], a generator 40 is housed in one part of the internal space of the chamber 2 and the stack of positioning elements 21, 22, 23, 24 and of the second electrodes 31, 32, 33 is housed in the other part.

[0109] Second type of arrangement (figures 10 to 12): peripheral filtering

[0110] In this type of arrangement, the first electrode 10 is peripheral and is preferably a cathode. The first electrode 10 is a hollow cylinder ([Fig.9]) in which are mounted the stack of positioning elements 21, 22, 23, 24 and the second electrodes 31, 32, 33.

[0111] The positioning elements 21, 22, 23, 24 are stacked coaxially in the internal space 115 of the first electrode 10 along the longitudinal axis of the first cylindrical electrode 10. The diameter of the positioning elements 21, 22, 23, 24 decreases from bottom to top.

[0112] The edge of each positioning element 21, 22, 23, 24 has a shape identical to the shape of the cross-section of the first cylindrical electrode 10, but with smaller dimensions, so that said positioning element 21, 22, 23, 24 can be placed in the internal space delimited by the first electrode 10, radially forming a filter space EPI, EP2, EP3, EP4 between said positioning element 21, 22, 23, 24 and the first electrode 10. Each filter space EPI, EP2, EP3, EP4 thus formed allows for the reception of rock material of smaller diameter or width. The filter spaces EPI, EP2, EP3, EP4 communicate fluidly with each other to circulate increasingly smaller pieces of rock material towards the collector 50.

[0113] Thus, in the example of [Fig.10]:

[0114] - the first positioning element 21 is arranged in the center of the first electrode 10 so as to radially form a first EPI filtering space between said first positioning element 21 and the first electrode 10,

[0115] - the second positioning element 22 is arranged above the first positioning element 21 at the center of the first electrode 10 so as to radially form a second filtering space EP2 between said second positioning element 22 and the first electrode 10, the width of said second filtering space EP2 being greater than the width of the first filtering space EPI and the support portion PP1 of the first positioning element 21 being configured to support the rock material elements located in said second filtering space EP2,

[0116] - the third positioning element 23 is arranged above the second positioning element 22 at the center of the first electrode 10 so as to form radially a third filter space EP3 between said third positioning element 23 and the first electrode 10, the width of said third filter space EP3 being greater than the width of the second filter space EP2 and the support portion PP2 of the second positioning element 22 being configured to support the rock material elements located in said third filter space EP3,

[0117] - the fourth positioning element 24 is arranged above the third positioning element 23 at the center of the first electrode 10 so as to radially form a fourth filter space EP4 between said fourth positioning element 24 and the first electrode 10, the width of said fourth filter space EP4 being greater than the width of the third filter space EPI and the third support portion PP3 of the third positioning element 23 being configured to support the rock material elements located in said fourth filter space EP4.

[0118] A cone-shaped directional element (not shown) can be positioned coaxially above the stack of positioning elements 21, 22, 23, 24 with the point upwards in order to direct the rocks introduced towards the center of the crusher 1 from above directly towards the fourth filtering space EP4.

[0119] In the example of [Fig. 10], the generator 40 is advantageously housed in the center of the first electrode 10 and the positioning elements 21, 22, 23, 24 in order to optimize the size of the crusher 1.

[0120] In the example of [Fig. 11], several generators 40 are advantageously housed in the center of the first electrode 10 and the positioning elements 21, 22, 23, 24 in a superimposed manner in order to optimize the size of the crusher 1, each generator 40 being connected to the first electrode 10 and to one and only one second electrode 31, 32, 33.

[0121] In the example of [Fig. 12], a single generator 40 is housed in one part of the internal space of the chamber 2 and the stack of positioning elements 21, 22, 23, 24 and of the second electrodes 31, 32, 33 is housed in the other part.

[0122] Third _ type of arrangement _([Fig. 13])

[0123] Figure 13 shows another example of the arrangement of the crusher 1 according to the invention 1 in which positioning elements 21, 22, 23, 24 are rectangular and positioned opposite each other in pairs. Each stage comprises a first linear electrode 10-1, 10-2, 10-3 in the form of a rod and a second linear electrode 31, 32, 33 also in the form of a rod, arranged opposite the first electrode 10-1, 10-2, 10-3. The filtering spaces EP1, EP2, EP3, EP4 are formed between the edges of the opposite positioning elements.

[0124] Additional equipment

[0125] Advantageously, the grinder 1 may further comprise an electronic controller and presence sensors (not shown) arranged in the filter spaces EPI, EP, EP3, EP4.

[0126] Each sensor is configured to detect the presence of rock material in a volume of a filter space EPI, EP, EP3, EP4 and to send detection signals to the electronic controller. The electronic controller is configured to control the generator 40 so that said generator 40 applies a voltage across the terminals of the first electrode 10 and at least one second electrode in order to trigger an electrical crushing discharge in said volume following the detection of rock fragments in the space associated with the sensor. The electronic controller includes a processor capable of implementing a set of instructions to perform these functions.

[0127] The grinder 1 can advantageously be configured to automatically control a series of electrical discharges between the first electrode 10 and at least one second electrode, preferably at a frequency between 1 and 15 Hz.

[0128] Shape of filter spaces

[0129] In the preceding examples, the EPI, EP2, EP3, EP4 filter spaces had a straight vertical shape.

[0130] Figure 14 shows another example of the configuration of the first EPI filter space having an elbow shape and Figure 15 shows another example of the configuration of the first filter space having a shape inclined at 45°.

[0131] Figure 16 shows an advantageous configuration of a positioning element 21 comprising a multitude of EPI filtering spaces formed in the support portion.

[0132] Example of implementation

[0133] An example of implementation will now be described with reference to [Fig.17].

[0134] As a prerequisite, the crusher 1 is arranged vertically in the position of use.

[0135] The rock material is introduced into the crusher 1 in a step El so as to allow the rock material elements MT to descend by gravity from top to bottom in a step E2, according to their size, into the filter spaces EP4, EP3, EP2, EPI, and at a minimum into the upper filter space (EP2 in the example of [Fig.4] and EP4 in the examples of Figures 5 to 13).

[0136] The positioning elements 21, 22, 23, 24 allow the positioning of the MT rock material at least partially within the successive EP4, EP3, EP2, EPI filter spaces, from the highest positioning element to the first positioning element 21 depending on the available space and the size of the MT rock material elements.

[0137] A portion of the rock material MT comes to be positioned between the first electrode 10 and at least one of the second electrodes 31, 32, 33 in a step E3 being supported by the support portion PP1, PP2, PP3 of the positioning element 21, 22, 23 located immediately below.

[0138] A flow of liquid F (see for example [Fig.4]), preferably water, is advantageously introduced continuously from the top of the crusher 1 in a step E4 to circulate the pieces of rock material from top to bottom through the filter spaces EPI, EP2, EP3, EP4 throughout the process.

[0139] Once the rock material is positioned at least in one of the filter spaces EPI, EP2, EP3, EP4, the voltage supplied by the generator 40 is applied in a step E5 between the first electrode 10 and the second electrodes 31, 32, 33 in order to trigger an electrical discharge between the electrodes 10, 31, 32, 33 of each pair of electrodes thus formed and then grind the rock material positioned between said electrodes 10, 31, 32, 33.

[0140] In doing so, the material crushed by the electrical discharges descends into the lower filter space to be ground again by electrical discharge, being further carried along by the downward water flow, until finally reaching the first EPI filter space below which it can be discharged from the crusher 1 in a step E6 to the collector 50.

[0141] Results

[0142] A prior art mechanical solution for crushing a mass of rocky material, containing copper, to a diameter of less than 200 sqm requires a very large amount of energy because it is necessary to crush all the material mechanically.

[0143] By using a rock material with a diameter of less than 15 mm at the inlet of the crusher 1 (width of the fourth filter space) and 1.5 mm at the outlet of the crusher 1 (width of the first filter space), the crusher 1 according to the invention makes it possible to produce a significant quantity of rock dust during successive discharges, on the order of 25% of the total mass at the inlet, which contains more than 70% copper, compared to 25% for the previous conventional methods by mechanical crushing and less than 50% for the previous conventional methods by electrical crushing.

Claims

1. Demands Rock material (1) crusher (1) by electrical discharge, said crusher (1) comprising: - a crushing chamber (2) comprising at least one side wall (3) defining an internal space (2A), an upper face (2B) through which the rock material (MT) is introduced and a lower face (2C) through which the crushed rock material (MT) is collected, - at least one first positioning element (21), made of an electrically insulating material, mounted in the internal space at the lower face of the chamber and positioned so as to form a first filtering space (EPI) allowing crushed rock material (MT) to be discharged through the lower face of the chamber (2), said at least one first positioning element (21) comprising on its upper surface, along the first filtering space, a support portion (PP1) configured to support rock material (MT), - at least one second positioning element (22), made of an electrically insulating material and whose dimensions are smaller than the dimensions of a first positioning element (21), each second positioning element (22) having a free edge (31 A) and being mounted in the internal space (2A) above a first positioning element (21) so that said free edge (31 A) delimits a second filtering space (EP2) extending above the support portion (PP1) of the first positioning element (21) located below and down to the first filtering space (EPI), the free edge (31 A) of the second positioning element (22) and the support portion (PP1) of the first positioning element (21) located below thus allowing rock material (MT) to be positioned in said second filtering space (EP2), - at least one pair of electrodes comprising a first electrode (10) and a second electrode (31), arranged opposite each other on either side of the second filtering space (EP2), - at least one generator (40) configured to apply a voltage between the first electrode (10) and at least one second electrode (31, 32, 33) so as to cause an electrical discharge to grind the rock material elements (MT) positioned in the second filtering space (EP2) and thus allow at least part of the crushed rock material (MT) to pass into the first filtering space (EPI) to be collected.

2. Crusher (1) according to claim 1, said crusher (1) comprising more than two positioning elements (21, 22, 23, 24) each made of an electrically insulating material and stacked one above the other, the dimensions of a higher positioning element being less than the dimensions of the immediately lower positioning element so as to form a filtering space of width greater than the width of at least one filtering space formed by the immediately lower positioning element and opening onto said filtering space formed by the immediately lower positioning element.

3. Crusher (1) according to any one of the preceding claims, said crusher (1) comprising a single first electrode (10) of cylindrical shape.

4. Crusher (1) according to the preceding claim, wherein the positioning elements (21, 22, 23, 24) are mounted inside the first electrode (10) and the filtering spaces are formed against the inner wall of said first electrode (10).

5. Crusher (1) according to claim 3, wherein the positioning elements (21, 22, 23, 24) are mounted around the first electrode (10) and the filtering spaces are formed against the outer wall of said first electrode (10).

6. Crusher (1) according to any one of claims 1 or 2, wherein at least one first electrode (10) and at least one second electrode (31, 32, 33) are of linear form.

7. Crusher (1) according to any one of the preceding claims, wherein the crusher (1) includes in its upper part at least one fluid inlet configured to deliver a flow of fluid to convey the pieces of rock material (MT) through successive filter spaces (EPI, EP2, EP3, EP4) according to their size to crush them and then discharge them.

8. Crusher (1) according to any one of the preceding claims, wherein the width of the first filter space (EPI) is less than 5 mm, preferably less than 3 mm, preferably even less than 2 mm.

9. Crusher (1) according to any one of the preceding claims, said crusher (1) further comprising at least one presence sensor configured to detect the presence of rock material (RM) between the electrodes of at least one pair of electrodes and thereby trigger a crushing shot.

10. A method for crushing rock material (RM) by electrical discharge, said method, implemented by a crusher (1) according to any one of the preceding claims arranged vertically in the operating position, comprising the steps of: - introduction of rock material (MT) through the upper face of chamber (2), - positioning of rock material (MT) at least in the filter space (EP2; EP4) defined by the highest positioning element (22; 24) between the electrodes (10; 31, 32, 33) of at least one pair of electrodes, said rock material (MT) being supported by the support portion (PP1, PP2, PP3) of the positioning element (21; 23) located immediately below the highest positioning element (22; 24), - triggering at least one electrical discharge at each stage, preferably a succession of discharges, from a voltage supplied by at least one generator (40) in order to grind the rock material (MT) positioned between said electrodes of each stage, - conveying the increasingly fine rock material (MT) through successive filtering spaces (EP4, EP3, EP2, EPI) from top to bottom, - evacuation of crushed rock material (MT) through the first filter space (EPI), preferably to a collector (50) fixed under the lower face of the chamber (2).

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