ES2536283T3 - Drain-rinse device and procedure of solid granular materials, rich in filiform particles (i.e. metal wires) - Google Patents

Abstract

Device for draining and occasionally rinsing a solid granular material rich in filiform particles (6) and loaded with fine particles, comprising: - a first vibrating screen (1) comprising a perforated plate (2) with holes (9), comprising a transverse median (X), said perforated plate (2) presenting an inclination (α) of between 1 and 10 ° with respect to the horizontal plane passing through said transverse median (X), a head portion (3) and a tail portion (4), said head portion (3) being located below said horizontal plane of said first vibrating screen (1) and said tail portion (4) being located above said horizontal plane of said first screen vibrating (1), - a feed (5) of said solid granular material rich in filiform particles (6) and loaded with fine particles established to feed said solid granular material rich in filiform particles (6) on the head portion (3) from said first sieve I saw brant (1), - at least one feed of an aqueous phase (7) to remove said fine particles by dragging, - an outlet of said solid granular material rich in filiform particles (6) drained, established for the recovery (14) of said solid granular material rich in filiform particles (6) in said tail portion (4), and - an outlet of said aqueous phase loaded with fine particles by gravity, under said first vibrating screen (1), characterized in that said perforated plate (2) with holes (9) has projections (8) directed from the face of said perforated plate (2) that receives said solid granular material rich in filiform particles (6) upwards, said projections (8) being each provided with they have at least one hole (9).

Description

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DESCRIPTION

Drain-rinse device and procedure of solid granular materials, rich in filiform particles (i.e. metal wires)

The present invention relates to a device for draining and occasionally rinsing a solid granular material rich in filiform particles and loaded with fine particles, comprising:

- a first vibrating screen comprising a perforated plate with holes, comprising a transverse median, said perforated plate having an inclination α of between 1 and 10 ° with respect to the horizontal plane passing through said transverse median X, a head portion and a tail portion, said head portion being located below said horizontal plane of said first vibrating screen and said tail portion being located above said horizontal plane of said first vibrating screen,

- a feed of said solid granular material rich in filiform particles and loaded with fine particles established to feed said solid granular material rich in filiform particles on the head portion of said first vibrating screen,

-at least one feed of an aqueous phase to eliminate by dragging said fine particles,

- an outlet of said solid granular material rich in drained filiform particles, established for the recovery of said solid granular material rich in filiform particles in said tail portion, and

- an outlet of said aqueous phase charged with fine particles by gravity, under said first vibrating screen.

A screening system is described, for example, in US 2237491, which discloses a sieve fed upstream with granular material of different particle sizes. As a result of the vibration, the finest particles pass through the sieve for further treatment, while particles that have a particle size greater than the size of the holes remain on the screen and travel, by gravity, the slope of the surface of the sieve. The holes are present on projections and face the direction of advance of the material. However, in the case of solid granular material rich in filiform particles, this type of sieve does not allow obtaining a correct screening, and one of the major problems faced is the obstruction of the fabrics or grids by fragments of cables and other materials. filiform, whose section is less than the opening of the holes of the sieve fabric, but whose twisted shape favors their accumulation on these fabrics, although the length of the filiform particles is in many cases greater than the size of said holes.

The term "solid granular material rich in filiform particles" typically means, within the meaning of the present invention, a material from a metal waste treatment in view of the recovery of metals or their concentrate. The referred material is rich in filiform particles such as metallic cables. Therefore, the "solid granular material rich in filiform particles" comprises particles that have a preferred direction, but also corrugated parts and which, therefore, can be wound on themselves or entangled with each other. Solid granular material rich in filiform particles is typically the result of a gravimetric concentration of metal residues in a dense medium. This operation can be carried out by means of a current screen.

On the other hand, documents FR1461603 and WO2009 / 013511, which disclose a device according to the preamble of claim 1 and a method according to the preamble of claim 6, both describe sieves for separating solid bodies according to their dimensions and its densities. As a result of vibrations, fine particles pass through a sieve, while larger particles trace along the sieve until a discharge. In the case of materials comprising abundant filiform particles, this type of sieve is subject to problems of sealing of the grilles or of the fabrics due to the presence of twisted filiform elements that accumulate and end up blinding the holes of the grids or of the fabrics.

Document DE19515349 concerns a method of separating solid particles of different sizes and of different densities in which the sieve subjected to vibrations includes projections and holes. This screen is inclined with respect to the horizontal according to an angle of at least 20 ° to ensure a correct separation of the different particles. However, such inclination is not adapted for the treatment of solid granular materials rich in filiform particles, since such slope favors, under the action of gravity, the accumulation of filiform materials in the holes located at the start of the projections, which ultimately leads to the sealing of these openings.

The object of the invention is to solve this problem by providing a device that allows the screening of products from the treatment of metallic waste by wet way that minimizes the sealing of the holes in the fabric. For this purpose, the invention provides a device for draining and occasionally rinsing a solid granular material loaded with fine particles characterized in that said solid granular material is rich in filiform particles and in that said perforated plate with holes has protrusions 8 directed from the face

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of said perforated plate 2 receiving said solid granular material rich in filiform particles 6 upwards, said projections 8 each being provided with at least one hole 9.

An inclination of between 1 and 10 ° advantageously allows the filiform particles to accumulate in the holes located at the start of the projections, due to gravity, with the consequent sealing of the latter.

Within the scope of the present invention, screening of the material from a wet metal waste treatment is proposed to separate, on the one hand, an aqueous phase from a solid phase comprising solid granular material rich in filiform particles. This means that the product from the treatment of metallic residues by wet route can already comprise an aqueous phase that must be separated from the solid granular material rich in filiform particles and, in this case, the solid granular material rich in filiform particles must be drained, and the solid granular material rich in filiform particles can occasionally be rinsed by an aqueous phase fed separately. In each of the aforementioned situations, the aqueous phase, either fed or residual from the treatment of metallic waste by wet way, or both, carries with it fine particles whose particle size is smaller than the size of the sieve holes (of the perforated plate).

As can be seen, according to the invention, said feed of solid granular material rich in filiform particles is operated inferiorly to the perforated plate in the head portion and the solid granular material rich in filiform particles traces the plate to the tail portion , where it is recovered for further treatment.

The aqueous phase, fed simultaneously with the solid granular material rich in filiform particles and / or separately, flows through the holes of the perforated plate and carries with it the fine particles. The aqueous phase flows by gravity, either on the plate, or under the plate, or both, depending on the place of the perforated plate through which the aqueous phase passes through the holes, in countercurrent with respect to the particle-rich solid granular material filiform that traces the sieve.

In this way, the vibration of the sieve and the lift of the material homogeneously distributes the solid granular material rich in filiform particles, which reduces the sealing of the holes, establishing the inclination to be such that it allows the advance of the rich solid granular material upward. in filiform particles, preventing them from descending due to the effect of gravity and, therefore, taking into account the density of the solid granular material rich in filiform particles to be treated.

In summary, granular materials (and especially cables and other filiform particles of lower section than the openings of the sheets) advance over the sheets without the possibility of penetrating into the openings or holes, by rebounding. On the contrary, the liquid flows by gravity in the opposite direction, giving it the possibility of precipitating through the openings and being recovered inferiorly to the vibrator. This liquid can carry fine particles smaller than the size of the openings and for which the drag effects of the liquid are greater than the effects of vibration. This peculiarity allows washing and rinsing operations at the same time that a drained product is recovered at the exit of the vibrator.

In this way, the granulometric spectrum of the solid granular material rich in filiform particles is greatly reduced in relation to a conventional treatment on a horizontal vibrator, where the average particle size of the resulting product is high.

Indeed, ordinary gravimetric concentration methods of metal recovery generally treat a product that has a spectrum of metal particle sizes for recovery between 10 µm and 300 mm. Existing rinse procedures only treat particles that are larger than 15 to 20 mm in size, because these procedures use relatively large holes to reduce sealing. Consequently, fine particles (d = 3 to 20 mm), if treated, would pass through the holes and be lost. If these procedures or devices for rinsing and / or draining used smaller holes to minimize losses, the sealing would be too frequent, thus requiring high labor costs to scrape and level the granular material and unclog the fabrics, something which makes the rinse / drain unprofitable and unprofitable.

In an advantageous embodiment, the draining and occasionally rinsing device according to the invention comprises a second vibrating screen comprising a perforated plate with holes comprising a transverse median, said perforated plate having an inclination with respect to the horizontal plane passing through said transverse median, a head portion and a tail portion, said head portion being located below said horizontal plane of said second vibrating screen and under said tail portion of said first vibrating screen and said tail portion being located above of the horizontal plane of said first vibrating screen; and wherein the output of said solid granular material rich in drained filiform particles is related to said tail portion of said second vibrating screen.

Therefore, by positioning the ladder plates, a turning of the materials is possible. In particular, the device according to the invention has a plurality of vibrating screens arranged in series.

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in relation to the direction of advance of the solid granular material rich in filiform particles. The vibrating sieves of said plurality are arranged in series, but in a staircase. Thus, the tail portion of the second sieve is located under the serial portion of said first sieve. The head portion of the second sieve is located above the tail portion of the next sieve, and so on until the last.

Consequently, when, in the advance of the solid granular material rich in filiform particles, it reaches the head portion, the granular material falls and turns to land on said second sieve, where it may, for example, pass through a new rinse. with the contest of another feeding of an aqueous phase.

Such a flip of the solid granular material rich in filiform particles allows an optimal rinse of the upper and lower part thereof.

The size of the openings is chosen based on the size of the particles that can be accepted in the recovered liquid.

Advantageously, said inclination is chosen in the range of between 1 and 5 °.

As previously stated, the amplitude, frequency and direction of vibration are adjusted in order to make the solid materials rise towards the tail end of the vibrator, the referred values based on the type of metallic waste treated by wet way.

According to the invention, thanks to the configuration of the vibrating screen, particles having a particle size from 3 mm and, for example, up to 300 mm, can be drained and occasionally rinsed successfully without plugging the holes. Consequently, the performance of the procedure will be much higher, as losses are reduced.

In a particularly preferred embodiment, each projection provided with at least one of said holes has a tile shape, said at least one of said holes being faced with said tail portion.

Preferably, the openings of the sheets are obtained by drawing in order to obtain a tile shape. These are preferably located at the triplet and are oriented such that the hole faces said tail portion of the perforated plate.

Consequently, the holes of the vibrating screen do not face the solid granular material rich in filiform particles that the sieve traces, which prevents the sections of cables or wires and the like from being able to get stuck in them and seal them. This particularly preferred embodiment virtually reduces the phenomenon of perforation of the perforated plate to zero.

Other embodiments of the device according to the invention are reported in the accompanying claims.

A subject of the present invention is also a draining and occasionally rinsing process of a solid granular material rich in filiform particles and loaded with fine particles, comprising:

- a feed of said solid granular material rich in filiform particles loaded with fine particles on a first vibrating screen in a head portion of a first perforated plate,

- a first ski lift of said solid granular material rich in filiform particles on said first perforated plate of said first vibrating screen towards a tail portion, by vibration of said first perforated plate, said first ski lift being made along an inclined path at an angle α of 1 at 10 ° from a horizontal plane,

- a first drain of said solid granular material rich in filiform particles with flow of said aqueous phase through said first perforated plate and a gravity recovery of said aqueous phase under said first vibrating screen, such that the aqueous phase and said solid granular material rich in filiform particles circulates relative to each other countercurrently in said perforated plate, and

-a recovery of said granular material rich in drained filiform particles. This process is characterized in that, during the vibration of said first perforated plate, said solid granular material rich in filiform particles bounces on the sieve and surrounds emerging protrusions of said perforated plate upwards (above or laterally),

- said first ski lift is made according to an average inclined path at an angle of 1 to 10 ° with respect to a horizontal plane.

As can be seen, the process according to the invention therefore allows, as mentioned above, a drain and occasionally a rinse of a solid granular material rich in filiform particles in which the solid granular material rich in filiform particles traces the perforated plate towards the tail portion, due to vibration effect, is distributed homogeneously, which favors the result of draining and occasionally

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of the rinse, reducing the sealing of the holes. Furthermore, in accordance with the invention and also to reduce the seals, the granular material rich in filiform particles traces said perforated plate with holes having an inclination of between 1 and 10 ° with respect to a horizontal plane passing through said transverse median. Such an inclination advantageously prevents that, due to gravity, filiform particles accumulate in the holes with which they face the other side of the projections, which, otherwise, could lead to the sealing of those.

In a particular embodiment, the method according to the invention also comprises:

- a turning of said solid granular material rich in filiform particles, after the first ski lift of said solid granular material rich in filiform particles on said first perforated plate of said first vibrating screen, on a second perforated plate of a second vibrating screen,

- a second lift by said solid granular material rich in filiform particles of said second perforated plate of said second vibrating screen, before said recovery, with a second drain of said solid granular material rich in filiform particles through said second plate perforated

Preferably, said second ski lift is carried out along an average inclined path at an angle of 1 to 10 °, preferably 1 to 5 ° with respect to a horizontal plane.

Preferably, said first ski lift is carried out along an average inclined path at an angle of 1 to 5 ° with respect to said horizontal plane.

Advantageously, in said second ski lift, said solid granular material rich in filiform particles bounces on the sieve and surrounds emerging protrusions of said perforated plate upwards (above or laterally).

In a preferred embodiment of the process according to the invention, said aqueous phase flows at least through holes which, present on said projections, face said tail portion.

Preferably, said recovered aqueous phase is recycled in view of reuse in said aqueous phase feed.

Preferably, in the process according to the invention, in said first and / or second ski lift, the solid granular material rich in filiform particles is further rinsed by an aqueous phase fed above said first and / or second perforated plate, respectively.

Other embodiments of the process according to the invention are described in the accompanying claims.

The invention also relates to a use of a device according to the invention for draining a solid granular material rich in filiform particles and occasionally rinsing a solid granular material rich in filiform particles.

Other forms of use are reported in the accompanying claims.

In the figures, identical or similar elements bear the same references.

Figure 1 is a view from one side of a device according to the invention.

Figure 2 is a sectional view of a projection of a perforated grid according to the invention, illustrated in turn in Figure 3.

Figure 4 is a perspective view of a preferred device according to the invention.

Figure 5 is a perspective view of a variant according to the invention of Figure 4.

As can be seen in figure 1, the device according to the invention comprises a vibrating screen 1 provided with a perforated plate 2. The vibrating screen comprises a transverse median X through which a horizontal plane passes. The plane of the perforated grid 2 of the vibrating screen 1 has an inclination of an angle α with respect to said horizontal plane, comprised between 1 and 10 °, preferably less than 8 °.

The perforated plate 2 has a head portion 3 and a tail portion 4 and, in view of said inclination, the head portion 3 is lower than the tail portion 4 and, therefore, is located under the referred horizontal plane. Consequently, the tail portion 4 is located above said horizontal plane.

The device according to the invention comprises a feed of solid granular material rich in filiform particles 5, loaded with fine particles. Said solid granular material rich in filiform particles 6 loaded with fine particles preferably comes from a treatment of metallic residues by wet route and, therefore, also comprises an aqueous phase.

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In the embodiment illustrated in FIG. 1, the device according to the invention also comprises a series of feeds of an aqueous phase 7 established to feed an aqueous phase intended to rinse the solid granular material rich in filiform particles 6 which is located on the perforated grid 2 of said vibrating screen.

The perforated grid is moved by the effect of an engine that confers an amplitude, frequency and a sense of vibration set to make the solid granular material rich in filiform particles 6 lift from the head portion 3 towards the tail portion 4, where it will then be recovered, occasionally for further treatment.

The aqueous phase from, on the one hand, the solid granular material rich in filiform particles 6 from the treatment of metallic residue by wet route, and / or from the aqueous phase feeds 7, on the other, rinses the solid granular material rich in particles filiform 6 that traces the vibrating screen 1 towards the tail portion 4, and the aqueous phase flows either over the perforated plate 2, or through holes 9 and then into the bowl 13 located inferiorly to the vibrating screen . This is then recovered by a suitable device 14 and transported for subsequent treatment and / or recycling, following the arrow B of Figure 1. Therefore, the solid granular material rich in filiform particles 6 traces the perforated plate following the middle direction. A and the aqueous phase circulate in countercurrent according to direction B by gravity. It is obvious that the directions A and B are resulting from the various paths of the solid granular material rich in filiform particles 6 and the aqueous phase, respectively, since the vibrations and the movement of the sieve cause a turbulent and disturbed movement of the latter.

The perforated plate 2 of the vibrating screen 1 further comprises projections 8 obtained by drawing, in order to obtain a tile shape, that is, projections 8 upwards having a top surface in a vault, as can be seen in Figure 2 , substantially flattened at the top in order to make as homogeneous as possible the advance of the solid granular material rich in filiform particles 6 towards the tail portion 4. Consequently, the upper face of the projection 8 has 2 lateral parts, inclined and curved 10 and 11 related at its top by a substantially flat face 12. Preferably, the thickness of the upper face of the projection is similar to that of the perforated plate 2, since the projections are obtained by drawing. Each projection has a longitudinal hole 9 of approximately 30 mm in the direction of the width of the perforated plate or of the transverse median X, that is, it has approximately the same width as that of the upper flat surface 12.

The height of the holes is generally between 200 µm and 3 mm. The longitudinal hole 9 faces the tail portion 4.

On the side of the projection 8 facing the head portion 3, in this preferred embodiment, there is an inclined, curved or not, solid face, that is, without holes, in order to avoid filiform particles of the solid granular material rich in filiform particles 6 attack in the holes and get the perforated plate 2 through its holes 8.

As can be seen in Figure 3, the projections are preferably aligned in the direction of the transverse median X and the three-leg in the direction of the longitudinal median. The holes 9 of the same row are preferably inscribed in an oblique or perpendicular plane relative to the plane of the perforated plate 2.

Figure 4 illustrates a preferred embodiment of the device according to the invention.

The illustrated device includes a first and a second vibrating screen 1, 1 ′ which respectively comprise a first and a second perforated plate 2, 2 ′. Of course, such a device may also comprise more than two vibrating sieves arranged in series and in a ladder, for example three.

In the preferred embodiment, each of the three vibrating sieves arranged in series and in a ladder includes two perforated plates arranged attached to a series testa approximately 1.7 m wide by 2 m long. This makes it possible, therefore, to have 3 vibrating sieves on the stairs, each of which includes two perforated plates, 4 m long and 1.7 m wide for a rinse and / or drained 12 m long. In the known devices, it was not possible to provide such a sieve / drained length, since the sieve was immediately sealed. With the device according to the invention, which is not sealed, it is advantageously possible to rinse the first side of the solid granular material rich in filiform particles on the two perforated plates of the first vibrating screen, rinse the second side of the solid granular material rich in filiform particles on the two perforated plates of the second vibrating screen thanks to the turning of the same and then, without additional rinsing, the solid granular material rich in filiform particles is drained on the two perforated plates of the third vibrating sieve to achieve optimum rinse and drained performance .

Returning to Figure 4, the solid granular material rich in filiform particles is then fed by feeding 5 onto the first perforated plate 2 of the first vibrating screen, in the head portion 3.

It is understood that, while the granular material is illustrated being fed to the head portion 3 of the first vibrating screen 1, this is by no means limiting. Indeed, solid granular material rich in filiform particles

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that has to be drained, it could also be fed to other places, for example in a more central part.

As a result of the vibrations, the solid granular material rich in filiform particles bounces and traces the first vibrating screen 1 inclined at an angle α to the horizontal (advantageously between 1 and 5 °). The solid granular material rich in filiform particles can be rinsed by an aqueous phase fed by rinsing jets 7 that pulverize the aqueous phase in its ski lift of the first vibrating screen 1. The solid granular material rich in filiform particles, when it reaches the portion of glue, falls on the second vibrating sieve 1 ′ per turn in order to allow the rinsing of the other side of the solid granular material rich in filiform particles.

The second vibrating screen 1 ′ includes, for example, a second perforated plate 2 ′ which is inclined at an angle α ′, identical or different in relation to α, although preferably between 1 and 5 °.

The solid granular material rich in filiform particles bounces and traces the second vibrating sieve 2 ′, where it can advantageously be rinsed by an aqueous phase fed by rinsing jets 7. The different rinsing jets 7 can spray the same aqueous phase or different aqueous phases , which can be water, an acidic, basic, detergent or neutralizing aqueous solution. The head position 3 of the second vibrating screen 1 ′ is located under the tail portion 4 of the first vibrating screen 1, partially overlapping, so that when the solid granular material rich in filiform particles reaches the tail portion 4, it falls again and it turns on the second vibrating sieve 1 ′, where it is recovered. The spacing between the vibrating sieves being dimensioned according to the granulometric fraction of the solid granular material rich in filiform particles, so that this can be turned a half turn for an optimal rinse.

In the illustrated embodiment, the solid granular material rich in filiform particles is recovered by dropping into a recovery cuvette 15 in view of further conditioning or further treatment located under the tail portion 4 of the second vibrating screen. The aqueous phase penetrates the holes 9 of the protrusions 8 of the first and second perforated plates 2, 2 ′ and is recovered below in the trough 13, by gravity, to then flow into an aqueous phase recovery device 14, countercurrent, following direction B in relation to solid granular material rich in filiform particles (direction A).

Figure 5 is a variant of Figure 4 in which the vibrating sieves 1, 1 ′ include a common trough 13.

Example

Washing of a polymetallic concentrate from a gravimetric concentration installation in a dense medium (water-magnetite), heavily contaminated with residual magnetite of granulometry of less than 300 µm (fine particles).

For this application, a width of the openings of 30 mm and a height of 500 µm was selected. In order to clean the particles, jets of rinse water were placed above the vibrator. A ladder was also placed in order to cause the particles to turn over. Each vibrating screen was inclined at an angle of 2 ° to the horizontal. The sieve vibrated at a frequency of 6.25 Hz and had a range of motion of 25 mm. The solid granular material rich in filiform particles had a feed rate of approximately 0.2 m / s and the rinse capacity was between 20 and 30 m3 / h.

The product to be washed has a strong contamination of magnetite on the surface of the metal fragments.

After washing, the product is relatively free of magnetite. It leaves the vibrator correctly drained, without any obstruction of the perforated plate being observed. In addition, the pulp (water-magnetite mixture) obtained inferior to the vibrator can be treated and recycled; the water can be used again for washing and the magnetite can return to integrate the gravimetric separation procedure in dense medium.

Of course, the present invention is not at all limited to the embodiments described above and that many modifications can be made therein without departing from the scope of the appended claims.

For example, the holes and projections of the grid may have other shapes and sizes than those described herein, for example, depending on the solid granular material rich in filiform particles to be treated.

Claims (13)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. Draining device and occasionally rinsing a solid granular material rich in filiform particles (6) and loaded with fine particles, comprising: - a first vibrating screen (1) comprising a perforated plate (2) with holes (9), comprising a transverse median (X), said perforated plate (2) having an inclination (α) of between 1 and 10 ° with respect to to the horizontal plane passing through said transverse median (X), a head portion (3) and a tail portion (4), said head portion (3) being located below said horizontal plane of said first vibrating screen ( 1) and said tail portion (4) being located above said horizontal plane of said first vibrating screen (1), - a feed (5) of said solid granular material rich in filiform particles (6) and loaded with fine particles established to feed said solid granular material rich in filiform particles (6) on the head portion (3) of said first vibrating screen (one), - at least one feed of an aqueous phase (7) to drag out said fine particles, - an outlet of said solid granular material rich in drained filiform particles (6), established for the recovery (14) of said solid granular material rich in filiform particles (6) in said tail portion (4), and - an outlet of said aqueous phase charged with fine particles by gravity, under said first vibrating screen (1), characterized by that said perforated plate (2) with holes (9) has projections (8) directed from the face of said perforated plate (2) receiving said solid granular material rich in filiform particles (6) upwards, said projections (8) being provided each of them with at least one hole (9). Device according to claim 1, further comprising a second vibrating screen (1 ′) comprising a perforated plate (2 ′) with holes (9) comprising a transverse median (X), said perforated plate (2 ′) having an inclination (α ′) with respect to the horizontal plane passing through said transverse median (X), a head portion (3) and a tail portion (4), said head portion (3) being located below said plane horizontal of said second vibrating screen (2 ′) and under said tail portion (4) of said first vibrating screen (1) and said tail portion (4) being located above the horizontal plane of said first vibrating screen (1); and wherein the output of said solid granular material rich in drained filiform particles (6) is related to said tail portion (4) of said second vibrating screen (1 ′).

3.

Device according to claim 1 or claim 2, wherein said inclination (α, α ′) is chosen in the range of 1 to 5 °.

Four.

Device according to claim 3, wherein each projection (8) provided with at least one of said holes

(9) has a tile shape, said at least one of said holes (9) facing said tail portion (4).

5.

Device according to any one of claims 1 to 4, comprising at least one feed of an aqueous phase (7) separated from said solid granular material rich in filiform particles (6) for rinsing said solid granular material rich in filiform particles (6) present on said perforated plate (2).

6.

Draining and occasionally rinsing process of a solid granular material rich in filiform particles (6) and loaded with fine particles, comprising:

- a feed (5) of said solid granular material rich in filiform particles (6) loaded with fine particles on a first vibrating screen (1) in a head portion (3) of a first perforated plate (2), - a first ski lift of said solid granular material rich in filiform particles (6) on said first perforated plate (2) having a transverse median (X) of said first vibrating screen (1) towards a tail portion (4), by vibration of said first perforated plate (2), said first ski lift being carried out along an inclined path an angle (α) of 1 to 10 ° with respect to a horizontal plane, - a first drained and occasionally a first rinse of said solid granular material rich in filiform particles (6) with flow of said aqueous phase through said first perforated plate (2) and a recovery (14) by gravity of said low aqueous phase said first vibrating screen (1), such that the aqueous phase and said solid granular material rich in filiform particles (6) circulate relative to each other countercurrently in said perforated plate (2), and - a recovery (14) of said granular material rich in filiform particles (6) drained, characterized in that, during said vibration of said first perforated plate (2), said solid granular material 8 rich in filiform particles (6) impinge on emerging protrusions (8) of said perforated plate (2) upwards. 7. Method according to claim 6, further comprising: - a turning of said solid granular material rich in filiform particles (6), after said first ski lift of said solid granular material rich in filiform particles (6) on said first perforated plate (2) of said first 5 vibrating sieve (1), on a second perforated plate (2 ′) of a second vibrating sieve (1 ′), - a second ski lift by said solid granular material rich in filiform particles (6) of said second perforated plate (2 ′) of said second vibrating screen (1 ′), before said recovery (14) with a second drain of said solid granular material rich in filiform particles (6) through said second perforated plate (2 ′). Method according to claim 6 or claim 7, wherein said first ski lift is carried out along an inclined average path an angle (α) of 1 to 5 ° with respect to said horizontal plane.

9.

Method according to claim 7 or 8, wherein said second ski lift is carried out along an inclined average path by an angle (α ′) of 1 to 10 °, preferably 1 to 5 ° with respect to a horizontal plane.

10.

Method according to one of claims 6 to 9, wherein, in said second ski lift, said

15 solid granular material rich in filiform particles (6) falls on protrusions (8) emerging from said perforated plate (2 ′) upwards. Method according to any one of claims 6 to 10, wherein said aqueous phase flows at least through holes (9) that, present on said projections (8), face said tail portion (4).

12.

Process according to any one of claims 6 to 11, wherein said recovered aqueous phase 20 is recycled in view of reuse in said aqueous phase feed (7).

13. A method according to any one of claims 6 to 12, wherein, in said first and / or second ski lift, the solid granular material rich in filiform particles (6) is further rinsed by an aqueous phase fed over said first and / or second perforated plate (2, 2 ′) respectively.

14.

Use of a device according to any one of claims 1 to 5, to drain and occasionally rinse a solid granular material rich in filiform particles (6).

9