Magnetic arrangement for transportation of magnetized material Description The present invention relates to an arrangement of magnets comprising at least two magnets M1 and M2, wherein M1 has a ratio of height k(M1 ) to length l(M1 ) of 0.2 to 2.0 and M2 has a ratio of height k(M2) to length l(M2) of 0.5 to 8.0 and wherein the ratio of height k(M1 ) to length l(M1 ) and the ratio of height k(M2) to length l(M2) are different, to an apparatus for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, comprising such an arrangement of magnets and to the use of this arrangement for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, using a magnetic field, wherein this magnetic field is provided by this arrangement. In a preferred embodiment, the present invention is related to effective transportation of magnetic or magnetized material in the presence of an external magnetic field, which is preferably provided by the arrangement of magnets according to the present invention. The transportation can be used for the separation of magnetic or magnetized material from a slurry or mixture containing this magnetic or magnetized material and non-magnetic material.

According to the present invention, two types of magnets that differ in respect of their ratios of height to length are used to optimize the two main directions of transportation independently. The first direction is towards the magnets and out of a mixture of magnetic and non-magnetic constituents, for example a slurry comprising a fluid, at least one magnetic and at least one non- magnetic particle. The second direction is along, for example parallel, the moved magnets to transport the collected at least one magnetic particle out of the slurry. In a further preferred embodiment of the present invention more than two different magnets may be present in the arrangement of magnets according to the present invention. In general, for wet magnetic separation processes, mainly three different types of magnetic separation equipment exist, low intensity magnetic separator (LIMS), wet high intensity magnetic separator (WHIMS) and finally high gradient magnetic separator (HGMS). These different types of magnetic separators are known to the skilled artisan. Among the LIMSs magnetic drum separators are the most common type. The drum separators have an arrangement of magnets inside the drum, which rotates through a mixture comprising the material that is to be separated and separates this magnetic material. In case of WHIMS and HGMS, a ferromagnetic matrix is used to locally enhance the magnetic forces and to capture the magnetic or magnetized particles within the volume of the separator. These types of separator are usually based on electromagnets.

The separators and magnetic arrangements that are used within these separators according to the prior art can still be improved in respect of efficiency of recovery and amount and quality of recovered valuables. In addition, these apparatuses known to the skilled artisan can still be improved in respect of loss of valuables during separation.

Object of the present invention is therefore to provide a magnetic arrangement and a separator for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material comprising this magnetic arrangement, wherein the efficiency of recovery and amount and quality of recovered valuables is improved and loss of valuables during separation is decreased. These objects are solved by an arrangement of magnets comprising at least two magnets M1 and M2, wherein M1 has a ratio of height k(M1 ) to length l(M1 ) of 0.2 to 2.0 and M2 has a ratio of height k(M2) to length l(M2) of 0.5 to 8.0 and wherein the ratio of height k(M1 ) to length l(M1 ) and the ratio of height k(M2) to length l(M2) are different, an apparatus for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized mate- rial and non-magnetic material, comprising such an arrangement of magnets and by the use of this arrangement for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, using a magnetic field, wherein this magnetic field is provided by this arrangement. According to a further embodiment, the present invention relates to an arrangement of magnets comprising at least two different magnets M1 and M2, wherein M1 has a ratio of height k(M1 ) to length l(M1 ) of 0.2 to 2.0 and M2 has a ratio of height k(M2) to length l(M2) of 0.5 to 8.0, by an apparatus for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material using a magnetic field, wherein this magnetic field is provided by the above mentioned arrangement, and by the use of an arrangement according to the present invention for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material.

The inventors of the present invention have found that a specific arrangement of magnets gives rise to an optimization of the transportation of magnetic or magnetized material, for example within a separator. According to a preferred embodiment of the present invention, the principal separation mechanism is conducted in a separator design wherein a fluid is moved within at least one canal and the arrangement of magnets according to the present invention is used to attract the magnetic or magnetized magnetic material and transport it at the same time in the desired direction.

It was surprisingly found that the arrangement of magnets according to the present invention gives rise to a minimization of the loss of the magnetic material during the transportation. Surprisingly, the optimized arrangement of the magnets also benefits the recovery of valuables from natural ores. It is further unexpectedly observed that the arrangement of magnets leads to lower loss of magnetic fraction and higher valuable recoveries as compared to other arrangements, for example according to the prior art. According to the present invention, the magnetic arrangement comprises at least two different types of magnets, more preferably two different types of magnets, wherein these magnets differ in respect of the above mentioned ratios of height and length. In a further preferred embodiment the magnetic arrangement according to the present invention comprises 2 to 250, more preferably 4 to 120, particularly preferably 10 to 80 magnets, wherein further preferred, the half of this total number of magnets are magnets M1 and the other half of this total number of magnets are magnets M2. For example the arrangement according to the present invention comprises 1 to 125, preferably 2 to 60, particularly preferably 5 to 40 magnets M1 in addition to 1 to 125, pref- erably 2 to 60, particularly preferably 5 to 40 magnets M2.

According to the present invention, in general, magnets M1 and M2 may be arranged in any order that is useful for the separation of magnetic or magnetized material from a mixture. According to a general description, m pluralities consisting of an arrangement of xM1 and yM2 magnets are present in the arrangement according to the present invention, wherein m, x, y is an integer equal or larger than 1. Within these pluralities, x and y may independently of another 1 , 2, 3, 4, 5, 6, 7, 8 or 9. According to this definition, for a simple alternating order, wherein one M1 is adjacent to one M2 etc. x and y are both 1 . In a preferred embodiment of the present invention, magnets M1 and M2 are arranged in an alternating order, meaning that one magnet M1 is followed by one magnet M2, being followed by another magnet M1 etc.

In a further embodiment of the arrangement according to the present invention, one magnet M1 is followed by another magnet M1 , being followed by a magnet M2, being followed by another magnet M2 etc.

In a further embodiment of the arrangement according to the present invention, one magnet M1 is followed by another magnet M1 , being followed by another magnet M1 , being followed by a magnet M2, being followed by another magnet M2, being followed by another magnet M2 etc.

In a further embodiment of the arrangement according to the present invention, one magnet M1 is followed by another magnet M1 , being followed by a magnet M2, being followed by a magnet M1 , being followed by another magnet M1 , being followed by a magnet M2, being followed by a magnet M1 etc.

In a further embodiment of the arrangement according to the present invention, one magnet M1 is followed by a magnet M2, being followed by another magnet M2, being followed by a magnet M1 , being followed by a magnet M2, being followed by another magnet M2, being followed by a magnet M1 etc. In a particularly preferred embodiment of the arrangement according to the present invention, at least one magnet M1 and at least one magnet M2 are arranged in an alternating order, meaning that one magnet M1 is followed by one magnet M2, being followed by another magnet M1 etc. The present invention therefore preferably relates an arrangement according to the present invention, wherein at least one magnet M1 and at least one magnet M2 are arranged in alternating order.

A key feature of the arrangement of magnets according to the present invention is that at least two different magnets M1 and M2 are present, wherein M1 has a ratio of height k(M1 ) to length l(M1 ) of 0.2 to 2.0, preferably 0.3 to 1.5, particularly preferably 0.5 to 1.0, and M2 has a ratio of height k(M2) to length l(M2) of 0.5 to 8.0, preferably 1.0 to 6.0, particularly preferably 2.0 to 4.0, wherein in each case, the ratio of height k(M1 ) to length l(M1 ) and the ratio of height k(M2) to length l(M2) are different.

For example, M1 has a ratio of height k(M1 ) to length l(M1 ) of 0.2 to 1 .8, preferably 0.5 to 1.5, particularly preferably 0.5 to 1 .0, and M2 has a ratio of height k(M2) to length l(M2) of 2.0 to 8.0, preferably 2.0 to 6.0, particularly preferably 2.0 to 4.0, wherein in each case, the ratio of height k(M1 ) to length l(M1 ) and the ratio of height k(M2) to length l(M2) are different.

According to the present invention the length I of a magnet is its physical size along one direction. According to this invention the direction of the length is preferably the direction of the flow in the used canals. According to the present invention, the length l(M1 ) of magnet M1 is in general 4 to 100 mm, preferably 10 to 80 mm, particularly preferably 15 to 60 mm, for example 20 mm. According to the present invention, the length l(M2) of magnet M2 is in general 2 to 80 mm, preferably 4 to 60 mm, particularly preferably 10 to 50 mm, for example 10 mm. According to a preferred embodiment of the invention, in the arrangement according to present invention, the ratio of the length of M1 l(M1 ) to the length of M2 l(M2) is 1.0 to 5.0, further preferred 1.5 to 3.0, particularly preferred 2.0 to 2.5.

Therefore the present invention preferably relates to an arrangement according to the present invention, wherein the ratio of the length of M1 l(M1 ) to the length of M2 l(M2) is 1.0 to 5.0.

According to the present invention the height k of a magnet is its physical size in one direction, different from length I. According to a preferred embodiment of the present invention, length I and height k are perpendicular to each other.

According to the present invention, the height k(M1 ) of magnet M1 is in general 4 to 100 mm, preferably 10 to 50 mm, particularly preferably 15 to 30 mm, for example 20 mm. According to the present invention magnet M1 can be one single magnet or can be provided by more than one magnet, for example two, three or four magnets that are preferably packed batchwise. In case that magnet M1 is provided by more than one magnet, these magnets are preferably equal in size. Furthermore, in case that magnet M1 is provided by more than one magnet, the height of magnet M1 is equal to the sum of the single magnets that are present. In a preferred embodiment of the present invention magnet M1 is provided by two magnets of same size.

According to the present invention, the height k(M2) of magnet M2 is in general 10 to 150 mm, preferably 20 to 80 mm, particularly preferably 30 to 45 mm, for example 40 mm. According to the present invention magnet M2 can be one single magnet or can be provided by more than one magnet, for example two, three or four magnets that are preferably packed batchwise. In case that magnet M2 is provided by more than one magnet, these magnets are preferably equal in size. Furthermore, in case that magnet M2 is provided by more than one magnet, the height of magnet M2 is equal to the sum of the single magnets that are present. In a preferred embod- iment of the present invention magnet M2 is provided by one single magnet.

According to as preferred embodiment of the invention, in the arrangement according to the present invention, the ratio of the height of M2 k(M2) to the height of M1 k(M1 ) is 1 .0 to 5.0, further preferred 1 .5 to 3.0, particularly preferred 1 .8 to 2.5.

Therefore, the present invention preferably relates to the arrangement according to the present invention, wherein the ratio of the height of M2 k(M2) to the height of M1 k(M1 ) is 1.0 to 5.0.

The at least one magnet M1 and/or the at least one magnet M2 may have any shape that is useful in an arrangement according to the present invention. The at least one magnet M1 and/or the at least magnet M2 may have a cylindrical, block-shaped, prismatic or irregular shape, preferably block-shaped.

According to the embodiment of the present invention, wherein the at least one magnet M1 and/or the at least one magnet M2 have a block-shaped shape, M1 and/or M2 comprise a width w(M1 ) and/or w(M2) as a further dimension, which is further preferred perpendicular to length I and height k. According to this embodiment of the present invention, the width w(M1 ) of magnet M1 is in general 4 to 120 mm, preferably 8 to 80 mm, particularly preferably 10 to 60 mm, for example 20 mm. According to the present invention, the width w(M2) of magnet M2 is in general 4 to 120 mm, preferably 8 to 80 mm, particularly preferably 10 to 60 mm, for example 10 mm.

According to the embodiment of the present invention, wherein the at least one magnet M1 and/or the at least one magnet M2 have a prismatic shape, the length of magnet M1 and/or M2 as mentioned above corresponds to the triangular base present in prismatic M1 and/or M2 hav- ing the above mentioned dimensions. According to this embodiment of present invention, M1 and/or M2 further comprise a width w(M1 ) and/or w(M2), which is further preferred perpendicular to the length. According to this embodiment of the present invention, the width w(M1 ) of magnet M1 is in general 4 to 120 mm, preferably 8 to 80 mm, particularly preferably 10 to 60 mm, for example 20 mm. According to the present invention, the width w(M2) of magnet M2 is in general 4 to 120 mm, preferably 8 to 80 mm, particularly preferably 10 to 60 mm, for example 10 mm.

In a particularly preferred embodiment of the magnetic arrangement according to the present invention, the at least one magnet M1 has a cylindrical shape. In this preferred case, the length of magnet M1 corresponds to its diameter. Therefore, according to the preferred case that magnet M1 das a cylindrical shape, the diameter of magnet M1 is the same as the length l(M1 ) and is in general 4 to 100 mm, preferably 10 to 80 mm, particularly preferably 15 to 60 mm, for example 20 mm.

According to a particularly preferred embodiment of the present invention the at least one magnet M1 has a larger width than the at least one magnet M2. This preferred embodiment of the present invention has the advantage that an increased towing power along the reactors wall is achieved. In general this towing force is located at the back end (in relation to its moving direction) of the at least one magnet M1 . Magnets M2 according to the present invention that have particularly preferably smaller width than the at least one magnet M1 are more useful for catching magnetic particles that are farer away from the magnets, but in general have a lower towing force than magnets M1. According to a further preferred embodiment, the at least one magnet M1 is block-shaped. In this preferred case, the length of magnet M1 is in general 4 to 100 mm, preferably 10 to 80 mm, particularly preferably 15 to 60 mm, for example 20 mm.

In a further preferred embodiment of the magnetic arrangement according to the present inven- tion, the at least one magnet M2 has a cylindrical shape. In this preferred case, the length of magnet M2 corresponds to its diameter. Therefore, according to the preferred case that magnet M2 das a cylindrical shape, the diameter of magnet M2 is the same as the length l(M2) and is in general 2 to 80 mm, preferably 4 to 60 mm, particularly preferably 10 to 50 mm, for example 10 mm.

According to a further preferred embodiment, the at least one magnet M2 is block-shaped. In this preferred case, the length of magnet M2 is in general 4 to 100 mm, preferably 10 to 80 mm, particularly preferably 15 to 60 mm, for example 20 mm. According to a particularly preferred embodiment of the arrangement according to the present invention, both, at least one magnet M1 and at least one magnet M2 have cylindrical shapes and comprise dimensions as mentioned above.

According to a further particularly preferred embodiment of the arrangement according to the present invention, both, at least one magnet M1 and at least one magnet M2 are block-shaped and comprise dimensions as mentioned above. The arrangement of magnets according to the present invention is preferably located at a tubular separator for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, using a magnetic field, wherein this magnetic field is provided by the above-mentioned arrangement. According to a first em- bodiment of the present invention, one arrangement of magnets comprising at least one magnet M1 and at least one magnet M2 is used in respect of one canal, preferably one loop-like canal. According to a second embodiment of the present invention, one arrangement of magnets comprising at least one magnet M1 and at least one magnet M2 is used in respect of more than one canal, preferably in respect of two, three, four or five canals, preferably loop-like canals. Accord- ing to a third embodiment of the present invention, more than one arrangement of magnets comprising at least one magnet M1 and at least one magnet M2, preferably two, three, four or five arrangements are used in respect of one canal, preferably one loop-like canal.

The width t of the canal, preferably of the loop-like canal, is in general adjusted to the dimen- sions of the arrangement of magnets. Preferably the ratio of the width t of the canal to the length l(M1 ) is 0.2 to 5.0, preferably 0.3 to 2.0. If a tubular canal is used according to the present invention, the width w t of the canal corresponds to projection from above. The width t of the canal is therefore preferably 2 to 200 mm, particularly preferably 10 to 150 mm, most preferably 20 to 80 mm.

According to a further preferred embodiment of the present invention at least one magnet M1 and at least one magnet M2 are arranged side by side, for example in alternating order as mentioned above. According to the present invention "side by side" means that magnets M1 and M2 are located in a way that their polarities, preferably their south- or north-poles, are pointing into the same or opposite directions, preferably into the same directions. According to the particularly preferred embodiment that arrangement of magnets M1 and M2 is located at a loop-like separator, "side by side" means that north- or south-poles are directing to the centre of the loop. The polarities of the magnets that are preferably arranged around the loop-like canal can be adjusted in any possible way. For example, the polarities of the magnets are adjusted alternately. Ac- cording to another embodiment, the magnets are adjusted with an alternating sequence of, for example, each 3 magnets with same direction of polarity followed by, for example, one magnet with alternated polarity. In a preferred embodiment all polarities of the magnets can be adjusted in the same direction. The preferred embodiment of the present invention, wherein all polarities of magnets M1 and M2 are adjusted into the same direction, for example all south poles point to the center of a loop like reactor, or all north poles point to the center of a loop like reactor, has the advantage that a concentration of field lines between the poles is achieved and the magnetic force pointing to magnetic particles that are located farer away from the magnets can be improved.

Furthermore, the preferred embodiment of the present invention, wherein all polarities of magnets M1 and M2 are adjusted into the same direction, for example all south poles point to the center of a loop like reactor, or all north poles point to the center of a loop like reactor, has the advantage that field lines between the poles are compressed and field lines having a sharper increase and therewith a stronger magnetic force onto a magnetic particle into the direction of the magnets are obtained.

According to a preferred embodiment of the arrangement according to the present invention, M1 and M2 are arranged around a loop-like canal and the south-poles of M1 and M2 are pointing to the centre of the loop. The present invention therefore preferably relates to the arrangement according to the present invention, wherein M1 and M2 are arranged around a loop-like canal and the south-poles of M1 and M2 are pointing to the centre of the loop.

Further preferred the arrangement of magnets M1 and M2 is mounted to a means for transport- ing them along a separator. For example the arrangement of magnets according to the present invention can be installed on a rotating device, for example on a conveyor belt, on a rotating drum as holder for the magnets or other rotatable constructions to hold the magnets. In a preferred embodiment the arrangement of magnets is attached to and moved during operation by a rotating device, preferably by a conveyer belt. The magnets of the arrangement according to the present invention are attached to this rotating device by any method known to the skilled artisan, for example using corresponding brackets, holder or further supporting means.

If at least one magnet M1 and at least one magnet M2 are arranged side by side, preferably in alternating order, the distance d between M1 and an adjacent M2 can be selected in a way that efficient separation of magnetic or magnetized material is possible. The distance between magnet M1 and magnet M2 must not be the same as the distance between magnet M2 and magnet M1 of the following sequence. Preferably there is the same distance d. According to the present invention, distance d preferably deviates from the centre of M1 to the centre of M2. According to a preferred embodiment of the present invention, distance d is 20 to 200 mm, preferably 22 to 120 mm, particularly preferably 25 to 80 mm.

According to a further preferred embodiment of the arrangement according to the present invention, the ratio between the distance d between M1 and an adjacent M2 and the length of M1 l(M1 ) is 1 .0 to 3.0, preferably 1 .1 to 2.5, particularly preferably 1.2 to 2.0.

According to a preferred embodiment of the arrangement according to the present invention, the at least one magnet M1 and/or the at least one magnet M2 may be selected from any type of magnet that are known to the skilled artisan, for example permanent or electrically switchable magnets, preferably permanent magnets. Permanent magnets are preferred, because the amount of energy that is consumed at operation can be decreased essentially, compared to the use of electro magnets. The present invention therefore preferably relates to the arrangement according to the present invention, wherein magnets M1 and M2 are permanent magnets.

According to a preferred embodiment of the present invention the at least one magnet M1 and the at least one magnet M2 are made of neodymium NdFeB. According to this a further preferred embodiment of the present invention the at least one magnet M1 and the at least one magnet M2 have an intrinsic induction N of N42 to N52, for example N48.

According to a further preferred embodiment of the present invention, the arrangement of mag- nets according to the present invention is located at the outside of a loop-like canal, wherein the distance between the outside of the canal and the inner side of the arrangement of magnets that is located around the canal and is called the gap. According to a preferred embodiment, the gap is essentially equal along at least part of the whole loop-like canal. In the sense of the present invention "essentially equal" means that the nominal gap between the arrangement of magnets and the outside of the loop-like canal is defined as 100% and the changes are within 95% to 105%, preferably within 97% to 103%, particularly preferably within 99% to 101 %, in each case based on the actual distance of 100%. The distance between the arrangement of magnets according to the present invention and the loop-like canal is for example 0.5 to 5 mm, preferably 0.8 to 3 mm, particularly preferably 1.0 to 2.5 mm.

The arrangement of at least one magnet M1 and at least one magnet M2 according to the present invention can in general be used in or at any apparatus that may have an advantage of this arrangement. In a preferred embodiment of the present invention, the arrangement of magnets according to the present invention is positioned at an apparatus for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, using a magnetic field, preferably for the separation of at least one first material from a mixture comprising this at least one first material and at least one second material using a magnetic field. According to this preferred embodiment, the magnetic field that is used for separation is provided by an arrangement according to the present invention.

The present invention therefore also relates an apparatus for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and nonmagnetic material, using a magnetic field, preferably for the separation of at least one first material from a mixture comprising this at least one first material and at least one second material using a magnetic field, wherein this magnetic field is provided by an arrangement according to the present invention.

The present invention further relates to the use of an arrangement according to the present invention for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, using a magnetic field, preferably for the separation of at least one first material from a mixture comprising this at least one first material and at least one second material. Particularly preferably, the present invention relates to an apparatus for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, comprising an arrangement of magnets according to the present invention.

General and preferred embodiments of this apparatus according to the present invention correspond to the general and preferred embodiments of the arrangement of magnets according to this invention.

Furthermore, the present invention relates to the use of an arrangement according to the present invention for the separation of magnetic or magnetized material from a mixture comprising this magnetic or magnetized material and non-magnetic material, using a magnetic field, wherein this magnetic field is provided by the arrangement according to the present invention.

General and preferred embodiments of this use according to the present invention correspond to the general and preferred embodiments of the arrangement of magnets according to this invention. In a particularly preferred embodiment, the arrangement of magnets according to the present invention is located in or at an apparatus for the separation of at least one first material from a mixture comprising this at least one first material and at least one second material.

The present invention therefore preferably relates to the arrangement according to the present invention, wherein it is located in or at an apparatus for the separation of at least one first material from a mixture comprising this at least one first material and at least one second material.

Preferably, the arrangement of magnets and the apparatus according to the present invention serve to separate magnetic constituents from an aqueous dispersion comprising these magnetic constituents and nonmagnetic constituents. The magnetic constituents can be originally magnetic by themselves or can be magnetized afterwards by the attachment of magnetic particles to non-magnetic particles.

According to the invention, the arrangement can in general be employed for separating all magnetic constituents from nonmagnetic constituents that form dispersion, preferably in water. In a preferred embodiment, the arrangement of the invention serves to separate aqueous dispersions which originate from the work-up of naturally occurring ores.

In a further preferred embodiment of the present invention, the aqueous dispersion to be separated originates from a process for separating at least one first material from a mixture compris- ing this at least one first material and at least one second material, with the at least two materials being separated from one another by treating the mixture in aqueous dispersion with at least one magnetic particle, resulting in the at least one first material and the at least one magnetic particle agglomerating and thus forming the magnetic constituents of the aqueous dispersion and the at least one second material and the at least one magnetic particle not agglomerating so that the at least one second material preferably forms the nonmagnetic constituents of the aqueous dispersion.

The agglomeration of at least one first material and at least one magnetic particle to form the magnetic constituents in general occurs as a result of attractive interactions between these particles, for example due to hydrophobicity of the surface of the at least one first material. Since the at least one second material preferably has a hydrophilic surface, the magnetic particles and the at least one second material do not agglomerate. A process for formation these magnetic agglomerates is described, for example, in WO 2009/030669 A1. For all details of this process, reference is expressly made to this publication.

For the purposes of the present invention, "hydrophobic" means that the corresponding particle can have been hydrophobicized subsequently by treatment with the at least one surface- modifying substance. It is also possible for an intrinsically hydrophobic particle to be additionally hydrophobicized by treatment with the at least one surface-modifying substance. Examples of suitable surface modifying substances are xanthates, dithiophosphates, long chain alcohol alkoxylates, siloxanes or mixtures thereof.

"Hydrophobic" means, for the purposes of the present invention, that the surface of a corresponding "hydrophobic substance" or a "hydrophobicized substance" has a contact angle of > 90° with water against air. "Hydrophilic" means, for the purposes of the present invention, that the surface of a corresponding "hydrophilic substance" has a contact angle of < 90° with water against air. The contact angle is acquired according to methods that are known to the skilled artisan, for example using a standard-instrument (Dropshape Analysis Instrument, Fa. Kruss DAS 10). A shadow image of the droplet is taken using a CCD-camera, and the shape of the droplet is acquired by computer aided image analysis. These measurements are conducted according to DIN 5560-2, if not stated otherwise. a) Preparation of a homogeneous powder film

The magnetite powder is placed as a ca. 1 mm thick layer on a PET foil using a 100 μηη thick BASF-Acronal-V215-adhesive-dispersion. Using a spatula, the powder is pressed into the ad- hesive and non adherent, excessive material is removed by shaking. Finally, remaining excessive material is removed using purified nitrogen under pressure over the sample. This process yields a clean, homogeneous powder surface along the whole area of the substrate of 75 mm x 25 mm. Powder surface normally show certain abrasiveness and contact angles or their analysis are sensible in respect of this abrasiveness. Therefore, a comparison of hydrophobicity is only possible using powders of same particle size distribution and particle shape. Careful analysis of surfaces using ToF-SIMS have shown that the surfaces of powder coatings that are obtained by this method do not comprise any leftovers of adhesive and are therefore representative in respect of this powder. b) Dynamic, advancing acquisition of the contact angle

One Milliliter of water is placed onto the surface as a droplet, and 2 μΙ/min water are added continuously. 20 μΙ volume of liquid in sum are added this way. Starting at a minimal volume of ca. 3 μΙ contact angles are acquired, while the needle that is used for dosage, remains in the drop- let. Measurements of shape are conducted with a frequency of about 0,5 Hz, analysis is conducted by a tangent method, in order to obtain the contact angle that is present at the boundary of the three phases. These contact angles are averaged over the time, five advancing droplets are acquired at different places and the average value is analyzed with a standard deviation. The formation of magnetic agglomerates, i.e. the magnetic constituents which can be separated off by the process of the invention, can also occur via other attractive interactions, for example via the pH-dependent zeta potential of the corresponding surfaces, see, for example, the International publications WO 2009/010422 and WO 2009/065802. Further methods for attaching magnetic particles and particles to be separated off include application of bifunctional mole- cules, like for example described in WO2010/007075. Another method for attaching magnetic particles and particles to be separated off include application of molecules being hydrophobic or hydrophilic depending on the temperature, like for example described in WO2010/007157.

According to a preferred embodiment of present invention, the arrangement according to the invention is used for the separation of at least one first material from a mixture comprising this at least one first material and at least one second material, wherein agglomerates of the at least one first material together with magnetic particles form the magnetic constituents. In a further preferred embodiment, the at least one first material is at least one hydrophobic metal compound or coal and the at least one second material which forms the nonmagnetic constituents is preferably at least one hydrophilic metal compound.

In a further preferred embodiment of the process according to the present invention, the at least one hydrophobic metal compound is selected from the group consisting of sulfidic ores, oxidic ores, carbonate-comprising ores, noble metals in elemental form, compounds comprising noble metals and mixtures thereof.

In a further preferred embodiment of the process according to the present invention, the at least one hydrophilic metal compound is selected from the group consisting of oxidic metal compounds, hydroxidic metal compounds and mixtures thereof.

Examples of the at least one first material to be separated off are preferably metal compounds selected from the group consisting of sufidic ores, oxidic and/or carbonate-comprising ores, for example azurite [Cu3(C03)2(OH)2] or malachite [Cu2[(OH)2|C03]], rare earth metals comprising ores like bastnaesite (Y, Ce, La)C0 ₃ F, monazite (RE)P0 ₄ (RE = rare earth metal) or chrysocolla (Cu,AI)2H2Si205(OH) ₄ ^■ n H2O, noble metals in elemental form and their compounds to which a surface-modifying compound can become selectively attached to produce hydrophobic surface properties. Examples of noble metals that may be present as at least first material are Au, Pt, Pd, Rh, etc., preferably in the native state or as sulphides, phosphides, selenides, tellurides or as alloys with bismuth, antimony and/or other metals.

Examples of sulfidic ores which can be separated according to the invention are, for example, selected from the group of copper ores consisting of covellite CuS, molybdenum(IV) sulfide, chalcopyrite (cupriferous pyrite) CuFeS2, bornite CusFeS ₄ , chalcocite (copper glass) CU2S, pendlandite (Fe,Ni)gS8, and mixtures thereof.

Suitable oxidic metal compounds which may be present as at least one second material accord- ing to the invention are preferably selected from the group consisting of silicon dioxide S1O2, silicates, aluminosilicates, for example feldspars, for example albite Na(Si ₃ AI)08, mica, for example muscovite KAl2[(OH,F) ₂ AISi ₃ Oio], garnets (Mg, Ca, Fe") ₃ (AI, Fe ^m )2(Si0 ₄ ) ₃ and further related minerals and mixtures thereof. Accordingly, untreated ore mixtures obtained from mines are preferably used as mixture comprising at least one first material and at least one second material in the process of the invention.

In a preferred embodiment of the present invention, the mixture comprising at least one first material and at least one second material in step (A) is in the form of particles having a size of from 100 nm to 100 μηη, see for example US 5,051 ,199. In a preferred embodiment, this particle size is obtained by milling. Suitable processes and apparatuses are known to those skilled in the art, for example wet milling in a ball mill. The mixture comprising at least one first material and at least one second material is therefore milled to particles having a size of from 100 nm to 100 μηη before or during step (A) in a preferred embodiment of the process of the invention.

Preferred ore mixtures have a content of sulfidic minerals of at least 0.2% by weight, particularly preferably at least 10% by weight.

Examples of sulfidic minerals which are present in the mixtures which can be used according to the invention are those mentioned above. In addition, sulfide of metals other than copper, for example, sulfides of iron, lead, zinc or molybdenum, i.e. FeS, FeS2, PbS, ZnS or M0S2, can also be present in the mixtures. Furthermore, oxidic compounds of metals and semimetals, for example silicates or borates or other salts of metals and semimetals, for example phosphates, sulfates or oxides/hydroxides/carbonates, and further salts, for example azurite

[Cu ₃ (C0 ₃ )2(OH)2], malachite [Cu ₂ [(OH) ₂ (C0 ₃ )]], barite (BaS0 ₄ ), monazite ((La-Lu)P0 ₄ ), spinels (Mg, Ca, Fe(ll))(Fe(lll), Al, Cr)20 ₄ , can be present in the ore mixtures to be treated according to the invention. A typical ore mixture which can be separated according to the present invention has the following composition: about 30% by weight of Si02 as an example of a preferred at least one second material, about 30% by weight of feldspar Na(Si3AI)08, about 3% by weight of CU2S as an ex- ample of a preferred at least one first material, about 1 % by weight of M0S2, balance chromium, iron, titanium and magnesium oxides.

Accordingly, with the arrangement according to the present invention is preferably used for the work-up of ore mixtures which have been obtained from mine deposits and which have been pretreated with appropriate magnetic particles.

To form the magnetic constituents of the preferably aqueous dispersion to be treated according to the invention, the at least one first material from the abovementioned group is brought into contact with at least one magnetic particle in order to obtain the magnetic constituents by at- tachment or agglomeration. In general, the magnetic constituents can comprise all magnetic particles known to those skilled in the art.

In a preferred embodiment, the at least one magnetic particle is selected from the group consisting of magnetic metals, for example iron, cobalt, nickel and mixtures thereof, ferromagnetic alloys of magnetic metals, for example neodymium NdFeB, SmCo and mixtures thereof, magnetic iron oxides, for example magnetite, maghemite, cubic ferrites of the general formula (I)

M ²⁺ _x Fe ²⁺ i-xFe ³⁺ ₂ 04 (I) where

M is selected from among Co, Ni, Mn, Zn and mixtures thereof and

x < 1 , hexagonal ferrites, for example barium or strontium ferrite MFeeO-ig where M = Ca, Sr, Ba, and mixtures thereof. The magnetic particles can additionally have an outer layer, for example of Si0 ₂ .

In a preferred embodiment, the magnetic particles used in the magnetic constituents are pre- sent in a size of from 100 nm to 200 μηη, particularly preferably from 1 to 50 μηη.

In a second preferred embodiment of the present invention, the magnetic constituents which shall be separated using the arrangement according to the present invention are magnetic particles themselves. According to this second embodiment magnetic particles themselves may be separated from the dispersion. The magnetic particles which are separated in this second embodiment of the invention are preferably selected from the group of magnetic particles as mentioned above. In the preferably aqueous dispersion to be treated according to the present invention, the magnetic constituents, i.e. preferably magnetic particles and/or agglomerates of magnetic particle and ore mineral are generally present in an amount which allows the aqueous dispersion to be transported or conveyed. The preferably aqueous dispersion to be treated according to the present invention preferably comprises from 0.01 to 10% by weight, particularly preferably from 0.2 to 3% by weight, very particularly preferably from 0.5 to 1 % by weight, in each case based on the total dispersion, of magnetic constituents. In the preferably aqueous dispersion to be treated according to the invention, the nonmagnetic constituents are generally present in an amount which allows the aqueous dispersion to be transported or conveyed in the apparatus according to the invention. The aqueous dispersion to be treated according to the invention preferably comprises from 3 to 50% by weight, particularly preferably from 10 to 45% by weight, very particularly preferably from 20 to 40% by weight, in each case based on the total dispersion, of nonmagnetic constituents.

According to the invention, a preferably aqueous dispersion is treated according to the invention, i.e. the dispersion medium is essentially water, for example from 50 to 97% by weight, preferably from 55 to 90% by weight, very particularly preferably from 60 to 80% by weight, in each case based on the total dispersion. However, the arrangement according to the present invention can also be applied to non aqueous dispersions or mixtures of solvents with water.

A preferred apparatus, wherein the arrangement according to the present invention is located, is defined and explained in International Patent Application PCT/EP2012/051540. This apparatus will be explained in the following:

An apparatus according to the present invention, wherein the arrangement according to the present invention is preferably located, is an apparatus for the separation of magnetic constituents from a dispersion comprising these magnetic constituents and nonmagnetic constituents, comprising at least one loop-like canal through which the dispersion flows having at least two inlets and at least two outlets, further comprising the arrangement according to the present invention that is moveable alongside the canal, wherein the canal is preferably arranged relative to gravity in a way that nonmagnetic constituents are assisted to go into the at least one first outlet by sedimentation and by the current of the dispersion and the magnetic constituents are forced into at least one second outlet by magnetic force against a current of flushing water. The second outlet is preferably only an outlet for solid magnetic constituents, but preferably not for fluids like dispersion or flushing water with flushed non-magnetic constituents. The flushing wa- ter is added at the at least second outlet of the loop-like canal, where only magnetic constituents are moved by the at least one magnet. In a preferred embodiment, the application of a flushing water stream is performed to rearrange the magnetic fraction, in order to free therein stored nonmagnetic constituents that are none-agglomerated with magnetic particles.

The arrangement of magnets according to the present invention is preferably located in or at a loop-like canal through which the dispersion flows having at least two inlet and at least two outlets. The preferred apparatus of the invention therefore preferably comprises at least one looplike canal through which the dispersion flows having at least two inlet and at least two outlets.

According to the present invention the wording "canal" describes the body structure of the separator. According to the present invention the wording "canal" describes a separator, which is, in its easiest embodiment, formed by a tube, e. g. the canal according to the invention has a length that is larger than the breadth or diameter of the canal. The cross-section of the canal can have any suitable shape, for example oval, annular, circular, square, rectangular, irregular or a combination of these shapes, preferably square or rectangular.

The preferred loop-like canal is designed to be able to separate magnetic constituents from nonmagnetic constituents in laboratory or industrial scale, preferably industrial scale.

According to a preferred embodiment of the present invention the canal is formed loop-like. According to the invention "loop-like" describes a canal, which, in a simple embodiment, is formed like a loop. Preferably the canal does not cross itself or end into itself. In a preferred embodiment the loop-like canal forms a part of a circular arc, for example at least 90°, preferably at least 120°, more preferably at least 180°, in particular at least 270°, for example not more than 350°, of a circular arc. In a further preferred embodiment of the present invention, the at least first inlet is present at one end of the loop-like canal and the at least two outlets are present at the other end of the loop-like canal. In a further preferred embodiment, after the first outlet there is the at least second inlet placed to flush the magnetic fraction before it reaches the at least second outlet. With this feature according to the present invention a very efficient and complete separation of magnetic constituents is possible.

The diameter of the loop that is constituted by the loop-like canal can be of any suitable size, for example 0.5 to 5 m, preferably 0.8 to 3.5 m, particularly preferably 1 .2 to 2.5 m. With these general and preferred diameters, a length of the loop-like canal, specifically a length of magnetic separation is for example 1 .25 to 12.5 m, preferably 2 to 9 m, particularly preferably 3 to 6 m.

According to a preferred embodiment of the present invention the arrangement of magnets ac- cording to the present invention is located along at least part of the loop-like canal, for example at the inside or outside of a loop-like canal, preferably at the outside, more preferably of the loop-like canal as defined above. In the sense of the present invention "along at least part of the loop-like canal" means that at least 30%, preferably at least 70%, particularly preferably at least 100% of the loop-like canal are surrounded by the arrangement of magnets according to the present invention. Furthermore, the loop-like canal through which the dispersion flows has at least two inlets and at least two outlets. In a preferred embodiment the loop-like canal through which the dispersion flows has one first inlet through which the dispersion comprising magnetic and nonmagnetic constituents is introduced into the canal, and two outlets. Through the first of these outlets the magnetic constituents are removed from the reactor (stream I). Through the second of these outlets the nonmagnetic constituents are removed from the reactor (stream II). Through one second inlet the flushing water is brought to the current of magnetic constituents to rearrange them and to free the stored nonmagnetic constituents therein. According to the present invention, further inlets and/or outlets may be present. Inlets and outlets that are present in the reactor of the present invention can be realized according to all embodiments known to the skilled artisan, for example tubings in suitable sizes, for example equipped with pumps, valves, means for controlling and adjusting etc.

In a preferred embodiment of the present invention, the arrangement of magnets is installed in a movable fashion at the outside of the loop-like canal. This preferred embodiment serves to move the arrangement of magnets in the longitudinal direction of the loop-like canal in order to separate the magnetic constituents from the nonmagnetic constituents. With the movable arrangements of magnets the magnetic constituents which are attracted by the magnetic field are likewise moved in the corresponding direction, being the at least one second outlet (stream II).

The apparatus comprising the arrangement of magnets according to the present invention can be operated by the arrangement of magnets and the preferably aqueous dispersion to be separated moving in the same direction. In this embodiment, the reactor is operated in concurrent. This embodiment is preferred.

In a further preferred embodiment of the apparatus of the invention, the arrangement of magnets and the preferably aqueous dispersion move in opposite directions. In this preferred embodiment, the apparatus of the invention is operated in countercurrent. With the apparatus comprising the arrangement of magnets according to the present invention, a flow velocity of the aqueous dispersion to be treated of for example≥ 200 mm/s, preferably > 400 mm/s, particularly preferably≥ 600 mm/s, is accomplished. These high flow velocities ensure that no blockages occur in the apparatus of the invention, in particular in countercurrent operation.

The velocity of the arrangement of magnets that is moveable alongside the canal is preferably adjusted in a fixed relation to the flow velocity of the dispersion which contains magnetic and non-magnetic constituents. This relation of velocities of the flow of the dispersion and of the at least one magnet is for example 0.5:1 , that means that the velocity of the arrangement of magnets is twice the velocity of the dispersion, preferably the relation is larger, particularly preferably 1 :1 to 20:1 , more preferably 2:1 to 10:1. For example, the relation is 4:1.

The present invention therefore preferably relates to an apparatus according to the present invention, wherein the relation of velocities of the flow of the dispersion and of the at least one magnet is larger than 0.5:1 , particularly preferably 1 :1 to 20:1 , more preferably 2:1 to 10:1. According to preferred embodiment of the present invention, an advantageous separation of magnetic particles, for example in respect of transportation and/or separation, is achieved, if a certain rational speed of magnets is adjusted in respect of the distance d between M1 and an adjacent M2. A less advantageous separation is achieved, if the distance d between M1 and an adjacent M2 is increased, but the rational speed of the magnets is kept constant. A separation comparable to the first embodiment is achieved, if both, the distance d between M1 and an adjacent M2 and the rotational speed of the magnets, are increased essentially equably, for example, both values are doubled.

As long as the essential features of the apparatus of the invention are complied with, the appa- ratus of the invention may have any further configuration. In a preferred embodiment it shall be ensured that the preferably aqueous dispersion to be separated has sufficient contact with the magnetic field of the at least one arrangement of magnets installed on the outside of the reactor. The apparatus according to the present invention can, in general, be made from any material that is known to the skilled artisan to be applicable to such an apparatus, for example nonmagnetic materials, preferably non-magnetic stainless steels or non-magnetic cast iron.

Further details of canals that can be used in accordance with the present invention are known to those skilled in the art and are described, for example, in process engineering textbooks.

According to the invention, the aqueous dispersion to be treated is preferably conveyed through the loop-like canal space preferably by means of a pump P1 . The flushing stream with which the magnetic constituents are treated is preferably conveyed by a pump P2. After the process of the invention has been carried out, the stream comprising the magnetic constituents obtained is preferably conveyed by a pump P3. In a particularly preferred embodiment of the process of the invention, the flushing stream can be divided by the matched pumps P2 and P3, with the volume stream P2 being greater than the volume stream P3. This achieves backflushing of the nonmagnetic constituents at a defined volume flow into stream at the at least one second outlet (stream II). Figures

Figure 1 shows an apparatus, wherein magnets are arranged concentrically around a separa- tion canal. This apparatus can be used with an arrangement according to the present invention (figure 2) or with an arrangement according to the prior art (comparative, figure 3) The numbers and abbreviations in figure 1 have the following meanings:

1 Feed

2 Flush

3 Discharge tailing fraction

4 Discharge magnetic fraction

5 Canal

6 Movable permanent magnets

7 Area/Magnets not used for the separation at this point of the loop, but which are moved to the separation area via the assembly rotation

I Length or diameter of permanent magnet

k Height of permanent magnet

R Radius of the separator device, for example 25 cm

d Distance between the magnets, for example 25 mm

S Canal height, for example 20 mm

a Distance between the magnet and the canal, for example 1 mm

Figure 2 (left side) shows an arrangement of magnets according to the present invention (ar- rangement B). The numbers and abbreviations have the following meanings:

M1 Magnet of type M1 , consisting of two cylindrical magnets, each with k = 10 mm and diameter I = 20 mm M2 Magnet of type M2, cylindrical magnet with k = 40 mm and diameter 1 = 10 mm Z Mounting of the permanent magnets on a rotation wheel Total number of magnets is 60.

Figure 2 (right side) shows a projection from above, t (canal width) = 5 mm

Figure 3 (left side) shows an arrangement of magnets according to the prior art (arrangement A). In figure 3, the abbreviations have the following meanings:

M magnet, consisting of two cylindrical magnets, each with k = 10 mm and diameter I = Figure 3 (right side) shows a projection from above. Total number of magnets is 30. Examples

As ore natural copper ore from Pelampres (Chile) is used. Starting concentration in the ore that has to be treated: Cu 0.79% by weight, Mo 0.0019% by weight and Fe 1.60% by weight.

Pretreatment of ore:

The ore is aridly milt in a hammer mill prior to the separation experiments, until 90% by weight of the ore that is present in the fraction has a size of less than 125 μηη.

Hydrophobized magnetite:

Hydrophobized magnetite with d50 of 3 μηη to 10 μηη is used for the experiment. This magnetite is commercially available from e.g. Lanxess.

General procedure:

150 g ore are conditioned in a planetary ball mill (900 g ZrC"2 as sphericals, diameter 2 to 2.5 mm) with 1 12.5 g water, 0.0285 g potassium-n-octylxanthate and 0.06 g Shellsol ^® D40 for 15 minutes. Subsequently, a suspension of 4.5 g hydrophobized magnetite in 3 g iso-propanol is added to the milling vessel and further conditioned for 5 minutes. The milling suspension is separated from grinding bodies, diluted to the required solid concentration (10% by weight in the case) and subjected to the separation procedure.

Separation procedure: 1 .5 L material as a 10% by weight suspension (feed) obtained from the "General procedure" to be separated is channeled across a chain of permanent magnets in the device described in International Patent Application PCT/EP2012/051540. The discharge obtained is collected as a fraction "tailings". The fraction attracted by the magnets is washed in-situ with water stream (flush) and is collected as fraction "magnetics" via a discharge pump (discharge). The fractions "tailings" and "magnetics" are analyzed in respect of Cu and Mo and the presence of magnetic residues. The exact experimental parameters are described in table 1. The analysis of the fractions obtained is summarized in tables 2 and 3.

Calculation of valuable distribution: For example, the tailing fraction having the mass m contains x% by weight of valuable 1 and the isolated magnetic fraction having the mass n contains y% by weight of valuable 1. The distribution (yield) of valuable 1 in the fraction will be: For the tailing fraction: W(tailings) = 100% ^* m ^* x/(m ^* x + n ^* y)

For the magnetic fraction: W(magnetics) = 100% ^* n ^* y/(m ^* x + n ^* y)

The higher valuable yield in the magnetic fraction W(magnetics) evidences higher degree of separation.

Determination of the magnetic content in the isolated fractions:

This is determined by measuring the attraction force between the sample and the permanent neodym magnet of a cylindrical form (diameter 20 mm, height 10 mm). For this purpose, the neodym magnet is based on a balance and the sample under study (0.5 g) is placed in a small glass vessel exactly above the magnet at a known distance. The force is calculated based on the negative mass difference displayed on the balance due to magnetic attraction of the magnetic particles in the studied sample and the neodym magnet. The distribution of the magnetics is calculated using the following formula:

Tailings: 100% ^* k ^* m/(k ^* m + I ^* n),

Magnetics: 100% ^* I ^* n/(k ^* m + I ^* n)

Where k and I are attraction forces (in g per 1 g) of the tailing and magnetic fractions, respectively, and m and n are the masses of tailing and magnetic fraction, respectively. The k ^* m and I ^* n values will be referred to as the total "magnetic equivalent" present in the isolated fractions. It should be noted that the investigated ore contained about 1 % by weight of natural magnetite, which also contributed to the measured attraction force values.

Table 1 shows the experimental parameters of example 1 to 3 (according to the invention) and 4 to 6 (comparative). Table 2 shows the distribution of magnetic components in Tailings and Magnetic fraction. Table 3 shows the distribution of valuables in Tailings and Magnetic fraction.

As seen from the pairs of example 1 to 3 (according to the invention) and 4 to 6 (comparative), the arrangement of the magnets according to the present invention leads to better separation of the magnetic fraction (mass magnetic content in tailings) and in addition higher recovery of valuable Cu and Mo compounds. Table 1. Experimental parameters

Table 2. Distribution of magnetic components in Tailings and Magnetic fraction

Table 3. Distribution of valuables in Tailings and Magnetic fraction

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