WO2011154540A1

WO2011154540A1 - Use of the naturally occurring magnetic components of ores

Info

Publication number: WO2011154540A1
Application number: PCT/EP2011/059736
Authority: WO
Inventors: Alexej Michailovski; Imme Domke
Original assignee: Basf Se; Siemens Aktiengesellschaft
Priority date: 2010-06-11
Filing date: 2011-06-10
Publication date: 2011-12-15
Also published as: EP2579987A1; PE20131009A1; AU2011263640A1; EP2579987B1; AU2011263640B2; PL2579987T3; CL2012003499A1

Abstract

The present invention relates to a method for separation of at least one first substance from a mixture containing this at least one first substance, at least one second substance and magnetic particles, comprising the following steps: (A) at least partial separation of the magnetic particles by application of a magnetic field gradient, possibly in the presence of at least one dispersion means, in order to obtain a mixture containing at least one first substance and at least one second substance and a reduced quantity of magnetic particles, (B) bringing the mixture containing at least one first substance and at least one second substance from step (A) into contact with magnetic particles, such that the at least one first substance and the magnetic particles accumulate, (C) separation of the accumulation product from the mixture from step (B) by application of a magnetic field gradient, and (D) splitting the separated accumulation product from step (C) in order to obtain the at least one first substance and the magnetic particles separately, as well as an open-loop and/or closed-loop control device for a corresponding apparatus.

Description

The present invention relates to a process for separating at least one first substance from a mixture containing said at least one first substance, at least one second substance and magnetic particles, comprising the following steps (A) at least partially separating the magnetic particles by applying a magnetic field gradient, optionally in the presence of at least one dispersing agent, to obtain a mixture containing at least a first substance and at least one second substance and a reduced amount of magnetic particles, (B) contacting the mixture containing at least one first substance and at least one second material from step (A) with magnetic particles, so that the at least one first material and the magnetic particles are applied, (C) separation of the adduct from the mixture from step (B) by applying n a magnetic field gradient; and (D) cleaving the separated adduct from step (C) to separately obtain the at least one first material and the magnetic particles. More particularly, the present invention relates to a method of enriching ores in the presence of gait.

Methods for separating ores from mixtures containing these are already known from the prior art.

WO 02/0066168 A1 relates to a process for the separation of ores from mixtures containing them, in which suspensions or slurries of these mixtures are treated with particles which are magnetic and / or floatable in aqueous solutions. After addition of the magnetic and / or buoyant particles, a magnetic field is applied so that the agglomerates are separated from the mixture. However, the degree of attachment of the magnetic particles to the ore and the strength of the bond is not sufficient to perform the process with sufficiently high yield and effectiveness. US Pat. No. 4,657,666 discloses a method for enriching ores, wherein the ore in orbit is reacted with magnetic particles, whereby agglomerates form due to the hydrophobic interactions. The magnetic particles are hydrophobized by treatment with hydrophobic compounds on the surface, so that a connection to the value ore takes place. The agglomerates are then separated from the mixture by a magnetic field. The The document also discloses that the ores are treated with a surface activating solution of 1% sodium ethylxanthogenate before the magnetic particle is added. Separation of ore and magnetic particles occurs in this process by destroying the surface-activating substance which has been applied to the ore in the form of the surface-activating solution. Furthermore, only C ₄ hydrophobizing agents for the ore are used in this process.

US 4,834,898 discloses a method for separating non-magnetic materials by contacting them with magnetic reagents coated with two layers of surfactants. US 4,834,898 further discloses that the surface charge of the non-magnetic particles to be separated may be affected by various types and concentrations of electrolyte reagents. For example, the surface charge is altered by the addition of multivalent anions, for example tripolyphosphate ions.

S.R. Gray, D. Landberg, N.B. Gray, Extractive Metallurgy Conference, Perth, 2-4 October 1991, pages 223-226 discloses a method for recovering small gold particles by contacting the particles with magnetite. Before contacting, the gold particles are treated with potassium amylxanthogenate. A method for separating the gold particles from at least one hydrophilic substance is not disclosed in this document.

WO 2007/008322 A1 discloses a magnetic particle, which is hydrophobized on the surface, for the separation of impurities from mineral substances by magnetic separation processes. According to WO 2007/008322 A1, a dispersant selected from sodium silicate, sodium polyacrylate or sodium hexametaphosphate may be added to the solution or dispersion. WO 2009/030669 A2 discloses a process for the separation of ores from mixtures of these with the gangue by magnetic particles, wherein the ore is first rendered hydrophobic with a suitable substance, so that the hydrophobized ore and the magnetic particles can be deposited and separated. WO 2009/065802 A2 discloses a similar method for separating a value ore from the gait by magnetic particles, the addition of magnetic particles and ore based on different surface charges. Both methods are still to be improved in terms of their efficiency.

The object of the present invention is to provide a method by which magnetic particles which are present in natural ore mixtures can be separated effectively, so that in the subsequent magnetic separation of the Do not disturb agglomerates containing ore, for example, to increase the space-time yield of the process, as well as a subsequent processing of the value ore to the process. A further object of the present invention is to provide a method by which at least one first substance, in particular a value ore, can be separated off efficiently from mixtures containing at least one first substance, at least one second substance, in particular the gangue, and magnetic particles. Furthermore, it is an object of the present invention to treat the first material to be separated so that the addition product between magnetic particles and first material is sufficiently stable to ensure a high yield of first material in the separation.

These objects are achieved according to the invention by a method for separating at least one first substance from a mixture containing said at least one first substance, at least one second substance and magnetic particles, comprising the following steps:

(A) at least partially separating the magnetic particles by applying a magnetic field gradient, optionally in the presence of at least one dispersant, to obtain a mixture containing at least a first substance and at least one second substance and a reduced amount of magnetic particles,

(B) contacting the mixture containing at least a first substance and at least one second substance from step (A) with magnetic particles so that the at least one first substance and the magnetic particles are deposited,

(C) separating the adduct from the mixture of step (B) by applying a magnetic field gradient and

(D) cleaving the separated addition product from step (C) to separately obtain the at least one first material and the magnetic particles.

In general, in the process according to the invention, it is possible to use all mixtures containing at least one first substance, at least one second substance and magnetic particles which are known to the person skilled in the art and from which the at least one first substance is to be separated by means of the process according to the invention.

In a preferred embodiment of the method according to the invention, the at least one first substance is at least one hydrophobic metal compound or carbon, and the at least one second substance is at least one hydrophilic metal compound. In the context of the present invention, "hydrophobic" means that the corresponding particle is inherently hydrophobic, or may be subsequently hydrophobized by treatment with the at least one surface-active substance It is also possible that a per se hydrophobic particle by treatment with the at least one surface-active substance is additionally rendered hydrophobic.

"Hydrophobic" in the context of the present invention means that the surface of a corresponding "hydrophobic substance" or a "hydrophobized substance" has a contact angle of> 90 ° with water against air. "Hydrophilic" in the context of the present invention means in a further preferred embodiment of the process according to the invention, the at least one hydrophobic metal compound is selected from the group of sulfidic ores, oxidic and / or carbonate ores For example, azurite [Cu ₃ (C0 ₃ ) 2 (OH) ₂ ], cupric [Cu ₂ 0] or malachite [Cu ₂ [(OH) ₂ | C0 ₃ ]]), or the noble metals and their compounds.

Examples of sulfidic ores which can be used according to the invention are, for example, Selected from the group of copper ores consisting of covellite CuS, molybdenum (IV) sulfide, chalcopyrite CuFeS ₂ , bornite Cu ₅ FeS ₄ , chalcocite Cu ₂ S, zinc blende ZnS, galena PbS, pentlandite (Ni , Fe) _x S with x approximately equal to 0.9, and mixtures thereof.

The at least one second substance is preferably selected from the group consisting of oxidic and hydroxide metal compounds, for example silicon dioxide Si0 ₂ , silicates, aluminosilicates, for example feldspars, for example albite Na (Si ₃ Al) O ₈ , mica, for example muscovite KAI ₂ [(OH , F) ₂ AISi ₃ Oi ₀ ], garnets (Mg, Ca, Fe ") ₃ (Al, Fe"') ₂ (Si0 ₄ ) ₃ , Al ₂ 0 ₃ , FeO (OH), FeC0 ₃ , Fe ₂ 0 ₃ , Fe ₃ O ₄ and other related minerals and mixtures thereof.

In the process according to the invention, therefore, preference is given to using untreated ore mixtures which are obtained from mine deposits. In a preferred embodiment of the method according to the invention, the first substances to be separated off are rendered hydrophobic on the surface.

In addition to the at least one first and at least one second substance, magnetic particles are present in the mixture to be treated according to the invention. According to the invention, all magnetic particles known to the person skilled in the art can be present in the mixture to be treated according to the invention.

In a preferred embodiment of the process according to the invention, the mixture to be treated according to the invention comprises magnetic particles selected from the group consisting of magnetic metals, for example iron, cobalt, nickel and mixtures thereof, ferromagnetic alloys of magnetic metals, magnetic iron oxides, for example magnetite (Fe ₃ 0 ₄ ⁾ , maghemite (Fe ₂ 0 ₃ ), pyrrhotite (Fei _-x S with 0 <x <0.5), ilmenite (FeTi0 ₃ ), other minerals of FeO-Fe ₂ 0 ₃ -Ti0 ₂ - Systems, cubic ferrites of general formula (I)

M ²⁺ _x Fe ²⁺ _1-x Fe ³⁺ ₂ 0 ₄ (I) with

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

x <1, hexagonal ferrites, for example barium or strontium ferrite MFei ₂ 0i ₉ with M = Mg, Ca, Sr, Ba, and mixtures thereof.

The average size of the magnetic particles present in the mixture to be treated according to the invention is generally from 100 nm to 100 μm. In the mixture to be treated according to the invention, the magnetic particles are generally in an amount of 0.05 to 10 wt .-%, preferably 0.1 to 5 wt .-%, particularly preferably 0.2 to 2 wt .-%, respectively based on the entire mixture, before. In a preferred embodiment of the method according to the invention, the mixture containing at least one first substance, at least one second substance and magnetic particles in step (A) is in the form of particles having an average size of 100 nm to 100 μm, see, for example, US Pat. No. 5,051,199 , In a preferred embodiment, this particle size is obtained by grinding. Suitable processes and devices are known to the person skilled in the art, for example wet milling in a ball mill.

Thus, a preferred embodiment of the method according to the invention is characterized in that the mixture containing at least a first material, at least one second material and magnetic particles before or during step (A) is ground into particles having a mean size of 100 nm to 100 μηη. Preferred mixtures have a content of at least one first material, in particular sulfidic minerals, of at least 0.4 wt .-%, particularly preferably at least 1 wt .-%, each based on the total mixture on. The at least one second substance, in particular oxidic minerals, is preferably present in an amount in the mixture to be treated according to the invention, so that the sum of magnetic particles, at least one first substance, at least one second substance and optionally further minerals yields 100% 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, sulfides of metals other than copper may also be present in the mixtures, for example sulfides of iron, lead, zinc or molybdenum, ie FeS / FeS ₂ , PbS, ZnS or MoS ₂ . 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 ), monacite ((La-Lu) P0 ₄ ). Further examples of the at least one first substance which is separated off by the process according to the invention are noble metals, for example Au, Pt, Pd, Rh, etc., preferably in a solid state.

A typically used ore mixture, which can be separated by the method according to the invention, has the following composition: about 30% by weight of Si0 ₂ , about 30% by weight of Na (Si ₃ Al) 0 ₈ , 2% by weight FeCuS ₂ , about 0.01 wt .-% MoS ₂ , about 1 wt .-% Fe ₃ 0 ₄ , balance chromium, iron, titanium and magnesium oxides.

The individual steps of the method according to the invention are described in detail below:

Step (A):

Step (A) of the method of the invention comprises at least partially separating the magnetic particles by applying a magnetic field gradient, optionally in the presence of at least one dispersant, to obtain a mixture containing at least a first material and at least one second substance and a reduced amount of magnetic particles ,

The separation of the magnetic particles can generally be carried out by any magnetic separation method known to those skilled in the art. Step (A) of the process according to the invention is carried out in one embodiment without addition of a dispersing agent, ie in the absence of a dispersing agent. Step (A) of the process according to the invention is carried out in a second, preferred embodiment in dispersion, ie in the presence of at least one dispersing agent, ie the at least one first substance comprising at least one second substance and the magnetic particle-containing mixture is present in at least one dispersing agent. If the mixture to be treated is provided in substance, the inventive step (A) of the process according to the invention preferably initially comprises the preparation of a dispersion. Processes for the preparation of a dispersion are known to the person skilled in the art.

As dispersants, all dispersants are generally suitable in which the mixture to be treated according to the invention is not completely soluble. Suitable dispersants are for example selected from the group consisting of water, water-soluble organic compounds, for example alcohols having 1 to 4 carbon atoms, and mixtures thereof. In a particularly preferred embodiment, the dispersant is water.

In general, the amount of dispersant may be selected to provide a dispersion which is readily stirrable and / or recoverable. In a preferred embodiment, the amount of mixture to be treated, based on the total slurry or dispersion, is 10 to 50% by weight, particularly preferably 25 to 40% by weight.

Suitable devices for magnetic separation, preferably on an industrial scale, are known in the art. Step (A) of the process according to the invention may be carried out in any apparatus known and suitable to those skilled in the art, for example in a wet drum separator, high gradient magnetic separator or related apparatus.

Step (A) of the process according to the invention may be carried out at any suitable temperature, for example 10 to 60 ° C.

In step (A) of the method of the invention, the magnetic particles present in the minerals to be treated are at least partially separated to obtain a mixture containing at least a first material and at least one second material and a reduced amount of magnetic particles. According to the invention, the magnetic particles in step (A) are generally at least 50%, preferably at least 60%, more preferably at least 70%, most preferably completely, separated. It is preferred according to the invention to separate off the largest possible proportion of the magnetic particles in step (A) of the process according to the invention, in order to obtain the described inventive advantages to the greatest possible extent.

After step (A), the separated magnetic particles may generally be separated from the remaining dispersion by any method known to those skilled in the art.

After step (A) of the process according to the invention, on the one hand, a mixture comprising at least a first and a second substance in a dispersion medium and, on the other hand, magnetic particles separated from one another are obtained.

The magnetic particles obtained in step (A) of the process according to the invention, in particular the ferromagnetic minerals, can be used as raw material according to the invention, and be supplied to processing methods known to the person skilled in the art, for example smelting processes.

In a further preferred embodiment of the process according to the invention, the magnetic particles separated in step (A) of the process according to the invention can be used in step (B) of the process according to the invention. In this preferred embodiment of the process according to the invention, the magnetic particles obtained in step (A) are optionally subjected to further steps before use in step (B), for example comminuting the particles to a mean size of 100 nm to 20 μm, preferably by wet milling.

The comminution is wet, preferably aqueous, in a ball mill, such. B. in a rotary or stirred ball mill. As a grinding medium inert body can serve with 1 to 50 mm in diameter, consisting of metal or preferably of ceramic materials.

Before use in step (B), the magnetic particles separated in step (A) are preferably rendered hydrophobic on the surface with at least one surface-active substance or, depending on the embodiment of step (B), suitably functionalized.

The hydrophobing is preferably carried out by contacting the comminuted magnetic particles, which are separated in step (A), with a suitable hydrophobing agent, for. Long-chain fatty acids, phosphonic acids, Phosphoric acid mono- or diesters, or their salts, alternatively with mono- or dialkylsilanols, for example, generated in situ by hydrolysis of corresponding alkyl alkoxysilanes, mono- or dialkylsiloxanes. The hydrophobization can be carried out in an aqueous or organic, preferably aqueous medium. In one embodiment, a drying and / or calcination step, for example at a temperature below 200 ° C, of the hydrophobized magnetic particle is carried out before reuse in step (B). However, a method which dispenses with this drying step is preferred. Advantage of the method according to the invention, in particular of the inventive step (A) is that disturbing magnetic particles are removed from the mixture before the actual separation of the at least one first substance for the entire process. By the separation according to the invention in step (A), the naturally occurring, in step (B) of the inventive method inactive magnetic particles are separated, whereby the space-time yield of the entire process can be increased. In addition, in the preferred embodiment in which the magnetic particles separated in step (A) are reused in step (B) of the method according to the invention, the amount of magnetic particles to be used can be reduced.

Step (B):

Step (B) of the method according to the invention comprises contacting the mixture containing at least one first substance and at least one second substance from step (A) with magnetic particles, so that the at least one first substance and the magnetic particles are deposited.

In step (B) of the process according to the invention, it is generally possible to use all magnetic particles known to those skilled in the art which satisfy the requirements of the process according to the invention, for example dispersibility in the dispersant used and the ability to form sufficiently stable agglomerates with the at least one first substance.

Furthermore, the magnetic particles should have a sufficiently high saturation magnetizability, for example 25-300 emu / g, and a low remanence so that the agglomerate can be separated from the dispersion in sufficient quantity in step (C) of the process according to the invention.

In a preferred embodiment of the method according to the invention, magnetic particles are used in step (B) of the method according to the invention, selected from the group consisting of magnetic metals, for example iron, Cobalt, nickel and mixtures thereof, ferromagnetic alloys of magnetic metals, magnetic iron oxides such as magnetite (Fe ₃ O ₄ ), maghemite (Fe ₂ O ₃ ), pyrrhotite (Fei _-x S where 0 <x <0.5), ilmenite (FeTi0 ₃ ), further minerals of the FeO-Fe ₂ 0 ₃ -Ti0 ₂ system, cubic ferrites of the general formula (I)

M ²⁺ _x Fe ²⁺ _1-x Fe ³⁺ ₂ 0 ₄ (I) with M selected from Co, Ni, Mn, Zn and mixtures thereof and

Very particular preference is given to using magnetite Fe ₃ O ₄ as magnetic particles in step (B).

The size of the magnetic particles used according to the invention is preferably from 10 nm to 1 μm.

In a particularly preferred embodiment of the process according to the invention, the magnetic particles separated off in step (A) are used in step (B). It is further possible that, in this preferred embodiment, the magnetic particles obtained in step (A) are added with further magnetic particles of the same or different type before being used in step (B).

In a preferred embodiment, the magnetic particles used in step (B) of the process according to the invention can be rendered hydrophobic on the surface with at least one surface-active substance, for example with at least one hydrophobic compound selected from compounds of the general formula

(Ii) B-Y (II) wherein

B is selected from linear or branched C ₃ -C ₃₀ -alkyl, C ₃ -C ₃₀ -heteroalkyl, optionally substituted C ₆ -C ₃₀ -aryl, optionally substituted C ₆ -C ₃₀ -

Heteroalkyl, C ₆ -C ₃₀ aralkyl and Y is a group with which the compound of the general formula (II) binds to the magnetic particles. In a particularly preferred embodiment, a linear or branched C ₆ -C C ₈ -C a linear Ci is B ₈ alkyl, preferably linear _C2 alkyl, most preferably ₂ alkyl. Optionally present heteroatoms are selected from among N, O, P, S and halogens such as F, Cl, Br and I. In a further particularly preferred embodiment, Y is selected from the group consisting of - (X) _n -SiHal ₃ , - ( X) _n -SiHHal ₂ , - (X) _n -SiH ₂ Hal with Hai equal to F, Cl, Br, I, and anionic groups such as - (X) _n -Si0 ₃ ^{3 "} , - (X) _n -C0 ₂ ^" , - (X) _n -PO ₃ ^2" , - (X) _n -PO ₂ S ^{2 "} ,

(X) _n -POS ₂ ² -, - (X) _n -PPS ₃ ² -, - (X) n-PS ₂ -, - (X) _n -POS ^" , - (X) _n -PO ₂ -, - (X) _n -C0 ₂ -, - {^ -Cz, "(X) n-

COS ^" , - (X) _n -C (S) NHOH, - (X) _n -S ^" with X = O, S, NH, CH ₂ and n = 0, 1 or 2, and, if appropriate, cations selected from the group consists of hydrogen, NR ₄ ⁺ with R equal independently of one another hydrogen and / or C 1 -C ₈ -alkyl, alkali metals, alkaline earth metals or zinc, furthermore - (X) _n -Si (OZ) ₄ with n = 0, 1 or 2 and Z = charge, hydrogen or short-chain alkyl radical. If n = 2 in the abovementioned formulas, then two identical or different, preferably identical, groups B are bound to a group Y.

Very particularly preferred hydrophobizing substances of the general formula (II) are alkyltrichlorosilanes (alkyl group having 6-12 carbon atoms), alkyltrimethoxysilanes (alkyl group having 6-12 carbon atoms), mono- and dialkyl esters of phosphoric acid (alkyl group having 6-15 carbon atoms), long-chain saturated and unsaturated fatty acids such as. For example, lauric acid, oleic acid, stearic acid or mixtures thereof. According to the invention, in step (B) of the process according to the invention, the at least one first substance to be separated off and the magnetic particles are deposited.

The annealing according to step (B) can generally be carried out by any attractive forces known to those skilled in the art between the at least one first material and the magnetic particles. According to the invention, essentially only the at least one first substance and the magnetic particles are deposited in step (B) of the method according to the invention, whereas the at least one second substance and the magnetic particles are essentially not deposited. In a preferred embodiment of the method according to the invention, the mixture containing at least a first substance and at least one second substance before or during step (B) to particles with a size of 100 nm to 100 μηη mow.

In a preferred embodiment of step (B) of the method according to the invention, the at least one first material and the magnetic particles are deposited due to hydrophobic interactions, different surface charges and / or compounds present in the mixture containing the at least one first material and the magnetic particles couple selectively, on. In the following, the mentioned alternatives for the attachment of the at least one first substance and the magnetic particles are explained in detail.

Embodiment B1: In this particularly preferred embodiment B1 of the process according to the invention, step (B) is carried out by first bringing the at least one first substance contained in the mixture into contact with a surface-active substance for its hydrophobization, and then further bringing this mixture into contact with magnetic particles is brought so that the magnetic particles and the at least one first, hydrophobicized on the surface, attach substance.

In the context of the present invention, "surface-active substance" means a substance which is able to change the surface of the particle to be separated, ie of the at least one first substance, in the presence of the other particles which are not to be separated off, The surface-active substances which can be used according to the invention are selectively attached to the at least one first substance and thereby bring about a suitable hydrophobicity of the first substance.

In the context of the present invention, "selectively attaching" means that the distribution coefficient of the surface-active substance between the surface of the at least one first substance and the surface of the at least one second substance is generally> 1, preferably> 100, particularly preferably> 10000, ie, that the surface-active substance preferably attaches to the surface of the at least one first substance, and not on the surface of the at least one second substance. In the embodiment B1 of step (B) of the process according to the invention, preference is given to using in the process according to the invention a surface-active substance of the general formula (III) AZ (III) which binds to the at least one first substance, in which

A is selected from linear or branched C ₃ -C ₃ -alkyl, C ₃ -C ₃ o-heteroalkyl, optionally substituted C ₆ -C ₃₀ aryl, optionally substituted C ₆ -C ₃₀ -

Heteroalkyl, C ₆ -C ₃₀ aralkyl and

Z is a group with which the compound of the general formula (III) binds to the at least one first material to be separated off.

In a particularly preferred embodiment, A is a linear or branched C ₄ -C 12 -alkyl, very particularly preferably a linear C ₄ - or C ₈ -alkyl. Optionally present heteroatoms according to the invention are selected from N, O, P, S and halogens such as F, Cl, Br and I.

In a further preferred embodiment, A is preferably a linear or branched, preferably linear, C ₆ -C ₂ o alkyl. Furthermore, A is preferably a branched C ₆ -C ₄ -alkyl, wherein the at least one substituent, preferably having 1 to 6 carbon atoms, is preferably present in the 2-position, for example 2-ethylhexyl and / or 2-propylheptyl.

In a further particularly preferred embodiment Z is selected from the group consisting of anionic groups - (X) _n -PO ₃ ^{2 "} , - (X) _n -PO ₂ S ^2" , - (X) _n -POS ₂ ^{2 "} , -

(X) _n -PS ₃ ² -, - (X) _n -PPS ₂ -, - (X) _n -POS-, - (X) _n -PO ₂ ^" , - (X) _n -PO ₃ ² - - (X 1 -CC, - (X) _n -CS ₂ -, - (X) _n -COS ^" , - (X) _n -C (S) NHOH, - (X) _n -S ^" with X selected from A group consisting of O, S, NH, CH ₂ and n = 0, 1 or 2, with optionally cations selected from the group consisting of hydrogen, NR ₄ ⁺ with R being independently of one another hydrogen and / or C 1 -C ₈ -alkyl, alkali metal The anions mentioned and the corresponding cations form according to the invention neutrally charged compounds of general formula (III).

If n = 2 in the abovementioned formulas, then two identical or different, preferably identical, groups A are bound to a group Z. In a particularly preferred embodiment, compounds are used which are selected from the group consisting of xanthates A-O-CS ₂ ^" , Dialkyldithiophosphates (A-O) ₂ -PS ₂ ^" , dialkyldithioposphinates (A) ₂ -PS ₂ ^" , dithiocarbamates A ₂ N-CS ₂ ^" , xanthogenic acid esters A-O-C (= S) -S-A ', thionocarbamates A- NH-C (= S) -S-A ', Carboxythionocarbamate A-0-C (= O) -NH-C (= S) -SA \ wherein A' each aryl or short-chain alkyl group, as well as unsaturated aliphatic radicals such B. Allyl, buten-2-yl, 2-methylpropen-2-yl, or selected from the group referred to A, and A is independently a linear or branched, preferably linear, C ₆ -C ₂₀ alkyl , for example n-octyl, or a branched C ₆ -C ₄ -alkyl, wherein the branching is preferably present in the 2-position, for example 2-ethylhexyl and / or 2-propylheptyl.As counterions, cations are preferably selected from these compounds the group consisting of hydrogen, NR ₄ ⁺ with R equal to independently hydrogen and / or CrC ₈ alkyl, alkali or alkaline earth metals, in particular sodium or potassium before.

Very particularly preferred compounds of the general formula (III) are n-octylxanthates, di-n-octyldithiophosphates, 2-ethylhexyl and 2-propylheptyl xanthates and -dithiophosphates, for example sodium or potassium n-octylxanthate, sodium or potassium di- n-octyl dithiophosphate, or mixtures of these compounds.

For noble metals, for example Au, Pd, Rh etc., particularly preferred surface-active substances are mono-, di- and trithiols or 8-hydroxyquinolines, for example described in EP 1 200 408 B1.

For metal oxides, for example FeO (OH), Fe ₃ O ₄ , ZnO etc., carbonates, for example azurite [Cu (CO ₃ ) ₂ (OH) ₂ ], malachite [Cu ₂ [(OH) ₂ CO ₃ ]] particularly preferred surface-active substances octylphosphonic acid (OPS), (EtO) ₃ Si-A, (MeO) ₃ Si-A, having the abovementioned meanings for A or long-chain saturated or unsaturated fatty acids, such as. As oleic acid, lauric acid, etc. In a preferred embodiment of the method according to the invention are used as surface-active substances no hydroxamates for the modification of metal oxides.

For metal sulfides, for example Cu ₂ S, MoS ₂ , etc., particularly preferred surface-active substances are mono-, di- and trithiols or xanthates.

In a further preferred embodiment of the process according to the invention, Z is - (X) _n -CS ₂ ^" , - (X) _n -PO ₂ ^" or - (X) _n -S ^" where X is O and n is 0 or 1 and one Cation selected from hydrogen, sodium or potassium Very particularly preferred surface-active substances are 1-octanethiol, potassium n-octylxanthate, potassium-butylxanthate, octylphosphonic acid or carboxythionocarbamates A-0-C (= O) -NH-C (= S ) -SA 'and oxycarbonylthioureas A-0-C (= O) -NH-C (= S) -NH-A' having the abovementioned meanings for A and A. The at least one surfactant is generally employed in an amount sufficient to achieve the desired effect. In a preferred embodiment, the at least one surfactant is used in an amount of from 5 to 1000 g per ton of the mixture to be treated.

Further details of this embodiment are disclosed in WO 2009/030669 A2.

Suitable magnetic particles are mentioned above. In embodiment B1, particular preference is given to using magnetic particles which are hydrophobized on the surface with at least one surface-active substance. Particularly preferred surface-active substances are the abovementioned compounds of the general formula (II). Embodiment B2:

In this further embodiment B2 of step (B) of the process according to the invention, the mixture of step (A) to be treated is first admixed with at least one hydrocarbon in an amount of from 0.01 to 0.4% by weight, based on the sum of contacting mixture and at least one hydrocarbon, and this mixture is further brought into contact with magnetic particles.

Embodiment B2 is particularly advantageous if, in addition to the least one first and at least one second substance, at least one third substance is present in the mixture. The at least one third substance is preferably selected from the group which has already been mentioned for the at least one second substance, wherein the at least one second and the at least one third substance are different. In the context of the present invention, hydrocarbon means an organic chemical compound which is composed essentially of carbon, hydrogen and optionally oxygen. If, in addition to carbon and hydrogen, oxygen is also present in the hydrocarbons which can be used according to the invention, this is present, for example, in the form of ester, carboxylic acid and / or ether groups. In step (B) according to embodiment B2 of the process according to the invention, it is possible to use both a substantially uniform hydrocarbon and a mixed carbon dioxide mixture.

Hydrocarbons or mixtures which can be used according to the invention generally have a low viscosity under the conditions of the process according to the invention, so that they are liquid under the process conditions according to the invention and are easily movable. Preferred hydrocarbons or mixtures are used which have a viscosity of from 0.1 to 100 cP, preferably from 0.5 to 5 cP, in each case at 20 ° C. Inventive hydrocarbons or mixtures generally have a flash point of> 20 ° C. , preferably> 40 ° C, on. Therefore, the present invention also relates to the inventive method, wherein the at least one hydrocarbon has a flash point of> 20 ° C, more preferably> 40 ° C.

In a preferred embodiment of the process according to the invention, the at least one hydrocarbon is selected from the group consisting of mineral oils, vegetable oils, biodiesel, BtL fuels (biomass-to-liquid), products of coal liquefaction, products of the GtL process (gas to liquid, from Natural gas) and mixtures thereof.

Mineral oils are, for example, crude oil derivatives and / or oils produced by distillation from brown coal, hard coal, peat, wood, petroleum and possibly also other mineral raw materials. Mineral oils generally consist of hydrocarbon mixtures of paraffinic, d. H. saturated chain hydrocarbons, naphthenic, d. H. saturated cyclic hydrocarbons, and aromatic hydrocarbons.

A particularly preferred crude oil derivative is diesel or gas oil. Diesel generally has a composition known to the person skilled in the art. Essentially, diesel is based on mineral oil, d. H. Diesel is a fraction in the distillative separation of mineral oil. The main components of diesel are predominantly alkanes, cycloalkanes and aromatic hydrocarbons having about 9 to 22 carbon atoms per molecule and a boiling range of 170 ° C to 390 ° C.

Other names for suitable petroleum derivatives include: light gas oil (boiling point 235-300 ° C, depending on specification also "diesel""dieselfuel""DK""light fuel oil""HEL"), heavy gas oil (boiling point 300 to 375 ° C), and (in the US) "No. 2 "vegetable oils are generally among the fats and fatty oils derived from oil crops.""Vegetable oils are, for example, triglycerides.""Vegetable oils useful in the present invention are selected from the group consisting of sunflower oil, rapeseed oil, thistle oil, soybean oil, corn oil, peanut oil, olive oil , Herring oil, cottonseed oil, palm oil and mixtures thereof. Biodiesel generally has a composition known to those skilled in the art. In essence, biodiesel contains methyl esters of saturated C ₆ -C ₈ - and unsaturated cis-fatty acids, especially rapeseed oil methyl ester. Products of coal liquefaction can be obtained, for example, by the Fischer-Tropsch or Sasol process. The BtL and GtL methods are known to the person skilled in the art.

In a preferred embodiment of the process according to the invention, in embodiment B2 of step (B), the hydrocarbon used is diesel, kerosene and / or light gas oil. On a laboratory scale, it is advantageous to use Solvesso® and / or Shellsol® brand diesel.

In step (B) according to embodiment B2 of the process according to the invention, it is optionally additionally possible to add at least one hydrophobicizing agent. Suitable hydrophobizing agents are the abovementioned compounds of the general formula (III).

Embodiment B3:

In this further embodiment B3 of step (B) of the process according to the invention, the mixture of step (A) to be treated is first brought into contact with at least one hydrophobizing agent so that an adduct forms from the at least one hydrophobizing agent and the at least one first substance. This adduct is then contacted with surface-functionalized with at least one polymeric compound having a LCST (Lower Critical Solution Temperature) functionalized magnetic particles at a temperature at which the polymeric compound has hydrophobic character such that the adduct and the functionalized magnetic particles agglomerate.

In embodiment B3 of step (B) of the process according to the invention, preference is given to using at least one hydrophobizing agent according to the general formula (III) shown above. With regard to the preferred embodiments, the above also applies.

The at least one water repellent is generally used in an amount sufficient to achieve the desired effect. In a preferred embodiment, the at least one hydrophobizing agent is added in an amount of from 0.01 to 5% by weight, based on the at least one first substance present in the mixture. Furthermore, the embodiment B3 of step (B) comprises contacting the adduct of at least a first material and hydrophobing agent with magnetic particles which are functionalized on the surface with at least one polymeric compound having a transition temperature LCST (Lower Critical Solution Temperature). As magnetic particles, those mentioned above can be used.

The magnetic particles are functionalized in the embodiment B3 on the surface with at least one polymeric compound.

The polymeric compounds used according to the invention are characterized in that they have a transition temperature LCST (Lower Critical Solution Temperature). Below this LCST, the polymeric compound has a hydrophilic character since the polymer chain has a hydration shell, for example due to addition of water molecules. Above the LCST, the polymeric compound has a hydrophobic character, since the polymer chain is no longer surrounded by a hydrate shell, for example. Depending on the polymeric compound, the reverse case is also possible, namely that the polymeric compound below the LCST has a hydrophobic character and has a hydrophilic character above the LCST. When such a polymeric compound is heated from below the LCST to a temperature above the LCST, the polymeric compound switches from hydrophilic to hydrophobic in the LCST, or vice versa. Thus, the polymers which can be used according to the invention, depending on the temperature, have a hydrophilic or hydrophobic character.

The change of the polymeric compound from hydrophobic to hydrophilic or vice versa corresponds to a phase transition, which takes place in a closed system generally in a narrow temperature range, for example 0.5 ° C. For example, in an open system, the phase transition may extend over a broader range of, for example, 15 ° C, by changing the concentration of the present components, for example, polymers and / or impurities, varying the pH and / or pressure. The temperature range at which the transition occurs generally increases with increasing chain length. When changing the molecular properties from hydrophilic to hydrophobic, generally some water molecules remain attached to the polymer, which are released suksezziv. This process is generally completely reversible as long as the polymeric compound is not chemically modified, for example by increasing the pH. The properties described for the polymeric compounds which can be used according to the invention are essentially correspondingly also present in the case of the particles modified with these polymeric compounds, in particular magnetic particles. In a preferred embodiment of the process according to the invention, the polymeric compound above the LCST is hydrophobic and hydrophilic below the LCST.

According to the invention, in embodiment B3 all polymeric compounds can be used which have an LCST, ie. H. which have hydrophilic or hydrophobic character at different temperatures. In the context of the present invention, "polymer" means a, preferably organic, compound having a molecular weight of at least 500 g / mol, preferably 500 to 10000 g / mol, particularly preferably 1000 to 7000 g / mol.

In a preferred embodiment of the process according to the invention, the at least one polymeric compound is selected from the group consisting of polyvinyl ethers, for example polyvinylmethyl ethers, poly-N-alkyl-acrylamides, for example poly-N-Ci-C ₆ -alkyl-acrylamides, in particular poly-N-isopropylacrylamide, or N-alkyl-acrylamide-acrylamide copolymers, poly-N-vinyl-caprolactams, copolymers based on alkylene oxides, for example copolymers of ethylene oxide, propylene oxide and / or butylene oxide, preferably polymeric compounds, obtainable by alkoxylation of Ci-Ci2-alcohols with 1 to 130 units of ethylene oxide, propylene oxide and / or butylene oxide, and mixtures thereof. Suitable polymeric compounds and methods for their preparation are described, for example, in Li et al., International Journal of Pharmacology (2006), 2 (5), 513-519, and Crespy et al., Polymer International (2007), 56 (12), 1461-1468, called. These polymeric compounds have hydrophobic character below the LCST and hydrophobic character above the LCST. The abovementioned polymeric compounds which have an LCST are bound by functional groups to the corresponding magnetic particles. These functional groups can be present in the abovementioned polymeric compounds per se, or the functional groups can be introduced into the polymeric compounds by processes known to those skilled in the art, ie the polymeric compounds are functionalized.

Suitable functional groups are those which ensure a sufficiently strong bond between magnetic particle and polymeric compound, for example selected from the group consisting of thiol group -SH, carboxylic acid group -C0 ₂ H, optionally at least partially esterified phosphonic acid group -P0 ₃ R ' ₂ with R' equal to hydrogen or C 1 -C ₆ -alkyl (Va), optionally at least partially esterified phosphoric acid group -O-P0 ₃ "2 with R" equal to hydrogen or C 1 -C ₆ -alkyl (Vb), hydroxamate group (Vc), xanthate group (Vd)

(Va) (Vb) (Vc) (Vd) and mixtures thereof, more preferably selected from the group consisting of thiol group -SH, carboxylic acid group -C0 ₂ H, optionally at least partially esterified phosphonic acid group -P0 ₃ R ' ₂ with R' is hydrogen or C 1 -C ₆ -alkyl (Va), optionally at least partially esterified phosphoric acid group -O-P0 ₃ R " ₂ with R" equal to hydrogen or C 1 -C ₆ -alkyl (Vb), hydroxamate group (Vc). The xanthate group (Vd) is preferably suitable for coupling to sulfidic compounds.

In a preferred embodiment, the at least one polymeric compound is at least one functionalized copolymer of ethylene oxide, propylene oxide and / or butylene oxide, more preferably a compound of general formula (VI)

F - [(EO) _x - (PO) _y - (BuO) _z ] -B (VI) wherein

F is a functional group which binds selectively to the at least one magnetic particle, B is an alkyl radical having 1 to 6 carbon atoms,

EO ethylene oxide,

PO propylene oxide,

BuO butylene oxide,

x is an integer or fraction from 0 to 130, preferably 0 to 40

y is integer or fractional number from 0 to 130, preferably 1 to 35 and

z is an integer or fraction from 0 to 130, preferably 0 to 40, where 1 <x + y + z <130, preferably 10 <x + y + z <130.

In the compound of the general formula (VI), F represents a functional group which selectively binds to the at least one magnetic particle. The choice of this functional group depends on the at least one magnetic particle to which the functional group is to bind. It should preferably a dissociation-stable bond arise between the at least one magnetic particle and the at least one polymeric compound of general formula (VI).

In a preferred embodiment, F is selected from the group consisting of carboxylic acid group -C0 ₂ H, optionally at least partially esterified phosphonic acid group -PO ₃ R 2 where R 'is hydrogen or C 1 -C ₆ -alkyl (Va), optionally at least partially esterified phosphoric acid group -O- P0 ₃ R " ₂ with R" equal to hydrogen or C 1 -C ₆ -alkyl (Vb), hydroxamate group (Vc), xanthate group (

(Va) (Vb) (Vc) (Vd) and mixtures thereof, particularly preferably an optionally at least partially esterified phosphonic acid group (Va) or an optionally at least partially esterified phosphoric acid group (Vb).

The binding of the functional groups Va to Vd to the polymer preferably takes place via lone-pair electrons.

In the general formula (VI) B is an alkyl radical having 1 to 6 carbon atoms, for example methyl, ethyl, propyl, butyl, for example n-butyl, pentyl, hexyl.

The polymeric compounds of the general formula (VI) have an LCST which is generally in each case dependent on the amount of the individual alkylene oxides, ie. H. Ethylene oxide, propylene oxide and / or butylene oxide, is dependent in the polymer. For example, a polymeric compound composed solely of propylene oxide has an LCST of <-10 ° C. A polymeric compound which is composed exclusively of ethylene oxide, for example, has an LCST of> 120 ° C. By selecting the type and amount of the alkylene oxides, it is thus possible to adjust an LCST of the polymeric compound which is suitable for the process according to the invention.

In a preferred embodiment, the LCST of the polymeric compound used in the process according to the invention is -10 to 100 ° C, more preferably 5 to 45 ° C, most preferably 20 to 40 ° C. In general, the LCST of a polymeric compound is in a temperature range of about 5 to 15 ° C. The width of this range is generally dependent on uniformity, ie the monodispersity, the polymeric compound used. The higher the monodispersity, the narrower the range of the LCST.

Processes for the preparation of polymeric compounds of the general formula (VI) are known to the person skilled in the art.

The functionalization of the magnetic particles with the at least one polymeric compound can be carried out by all methods known to the person skilled in the art. In a preferred embodiment, the magnetic particles are functionalized with the at least one polymeric compound by first preparing the magnetic particles themselves by known methods. Then, these magnetic particles are modified by contacting a solution of the functionalized polymeric compound, especially compounds of the general formula (VI), in water or in an organic solvent, for example low molecular weight alcohols or ketones, and the product obtained is used to remove excess polymer Washed compound with an appropriate solvent.

The contacting in embodiment B3 of step (B) is preferably carried out at a temperature at which the polymeric compound employed has hydrophobic character so that the switchably functionalized magnetic particles and the hydrophobized at least one first material agglomerate. Depending on the polymeric compound, this temperature may be above or below the LCST, preferably the temperature is above the LCST.

Preferably, contacting in embodiment B3 of step (B) is performed at a temperature greater than the LCST of the polymeric compound and less than the boiling point of the suspending agent used, more preferably at a temperature of from 1 to 20 ° C above the LCST lies. Thus, the contacting according to embodiment B3 is carried out in a preferred embodiment at a temperature of 6 to 65 ° C, particularly preferably 21 to 60 ° C.

In the case where the polymeric compound has hydrophobic character below the LCST, the contacting in embodiment B3 is carried out at a temperature which is above the melting temperature of the suspending agent employed and below the LCST of the polymeric compound. Preferably, in this case, the contacting in embodiment B3 is carried out at a temperature which is 1 to 20 ° C below the LCST. For this case, the contacting in embodiment B3 is thus preferably carried out at a temperature of -15 to 44 ° C, particularly preferably 0 to 39 ° C. Embodiment B4:

In this further preferred embodiment B4, step (B) of the process according to the invention is carried out by preparing a dispersion of the mixture containing at least a first substance and at least one second substance and the magnetic particles in a suitable dispersing agent, and adjusting the pH of the resulting dispersion to a value at which the at least one first material and the magnetic particles carry opposite surface charges so that they agglomerate.

As magnetic particles, it is possible to use all magnetic particles known to the person skilled in the art which satisfy the requirements of embodiment B4 of step (B) of the process according to the invention, for example dispersibility in the dispersant used and the ability to agglomerate with the at least one first material. Furthermore, the magnetic particles should have a defined occupancy with surface charges at a defined pH. These surface charges can be quantified with the so-called ξ-potential. The above-mentioned magnetic particles are preferably used.

In a preferred embodiment of the process according to the invention, the dispersion prepared according to embodiment B4 of step (B) contains at least one buffer system. Suitable buffer systems for setting a specific pH are known to the person skilled in the art and are commercially available. For a weakly acidic pH range (pH = 5.0-6.2), for example, the carbonic acid-silicate buffer is suitable. A similar pH range (pH = 5.2-6.7) can be adjusted by 2- (N-morpholino) ethanesulfonic acid. For a pH value in the alkaline range (pH = 8.2-10.2), the ammonia buffer is suitable. The addition of a buffer system to the suspension serves to adjust a suitable pH, which is relatively stable.

The dispersion prepared according to embodiment B4 of step (B) of the process according to the invention preferably has a pH of from 2 to 13. The pH of the dispersion produced depends on the isoelectric points of the substances to be separated. The limits of the pH range are also determined by the stability of the magnetic particles used, for example, Fe ₃ 0 ₄ below pH 2.88 is not stable.

According to the invention, the pH of the resulting dispersion is adjusted to a value at which the at least one first substance and the magnetic particles carry opposite surface charges, so that they agglomerate. The agglomeration of the at least one first substance and the magnetic particles is based on their different surface charge in aqueous suspension as a function of the pH. The surface charge of a particle in equilibrium with the surrounding liquid phase is determined by the zeta potential ξ. This varies depending on the pH of the solution or suspension. At the isoelectric point (IEP), the surface charge of the particle changes sign, ie exactly at the isoelectric point, the zeta potential ξ to be measured is zero. If the zeta potential ξ on a y-axis is plotted against the pH value on the x-axis in a coordinate system, the resulting curve intersects the x-axis at the isoelectric point.

Particles with different surface charges agglomerate with each other, while equally charged particles repel each other.

In the dispersion prepared according to embodiment B4 of step (B), at least one first substance, at least one second substance and magnetic particles having the isoelectric points IEP (1), IEP (2) and IEP (M) are present, wherein IEP (1) <IEP (M) <IEP (2) applies. The following relationship is IEP (1) <pH <IEP (M), i. the pH of the suspension is between the isoelectric points of the at least one first material and the magnetic particles, then the at least one first material and the magnetic particles have opposite surface charges, while the at least one second material and the magnetic particles are the same Have surface charge, so that the at least one first material and the magnetic particles agglomerate. Similarly, when the pH is between the isoelectric point of the magnetic particles and the at least one second material, it behaves the same way. H. IEP (M) <pH <IEP (2) so that the magnetic particles and the at least one second material agglomerate while the magnetic particles and the at least one first substance repel due to the same surface charge.

The determination of the isoelectric point of the substances present in the mixture, comprising at least one first substance, at least one second substance and magnetic particles, can take place via the ξ-potential of the individual substances in aqueous solution. The measured ξ potential varies with the type of device used, the method of measurement and the evaluation method. Important parameters to be reported are temperature, pH, concentration of the salt background solution, conductivity and measurement voltage, so that the parameters mentioned must be known for comparable measurements. Further details and exemplary isoelectric points of various preferred metal oxides and sulfides are disclosed in WO 2009/065802 A2, the contents of which are expressly referred to. In the preferred embodiment B4 of step (B) of the method according to the invention, therefore, the pH is preferably set to a value which lies between the isoelectric point of the at least one first substance and the isoelectric point of the magnetic particles. The pH can be adjusted by all methods known to the person skilled in the art, for example adding at least one basic or at least one acidic compound to the dispersion obtained. Whether a basic or an acidic compound has to be added depends on the pH of the prepared dispersion. If the pH of this dispersion is less than the region between the isoelectric point of the at least one first substance and the isoelectric point of the magnetic particles, at least one base is added to increase the pH. If the pH of this dispersion is greater than the region between the isoelectric point of the at least one first substance and the isoelectric point of the magnetic particles, at least one acid is added to lower the pH.

Suitable basic compounds are selected from the group consisting of organic or inorganic bases, for example ammonia, sodium hydroxide NaOH, potassium hydroxide KOH, amines, for example triethylamine, soluble alkali metal carbonates and mixtures thereof.

Suitable acidic compounds are selected from the group consisting of organic or inorganic acids, for example mineral acids such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, organic acids such as formic acid, acetic acid, propionic acid, methanesulfonic acid and mixtures thereof.

For example, the pH for separating Cu ₂ S from SiO _{2 is} preferably adjusted to pH 3. For the separation of MoS ₂ from Si0 ₂ , the pH is preferably adjusted to> 2.

Embodiment B5:

In this further preferred embodiment B5 of step (B) of the process according to the invention, the magnetic particles are used together with at least one bifunctional molecule of the general formula (VII) (F ¹ ) _x - (A) _n - (F ² ) _y (VII) wherein F ^{1 is a} functional group that selectively binds to the at least one magnetic particle, F ^{2 is a} functional group that selectively binds to the at least one first material, A structural unit selected from CRH ₂ group with R selected from hydrogen or linear or branched carbon radical having 1 to 30 carbon atoms, aromatic or heteroaromatic unit, cyclic or heterocyclic unit, unsaturated, branched or unbranched carbon chain with 2 to

30 carbon atoms, heteroatom or combinations of the abovementioned structural units,

n integer from 1 to 100,

x integer from 1 to 4 and

y is an integer from 1 to 4, or an adduct of both is brought into contact with the mixture comprising the at least one first substance and at least one second substance, so that the magnetic particles, the bifunctional compound of the general formula (VII), and the at least one first substance forms an adduct.

F ¹ and F ² each represent functional groups which bind selectively to the magnetic particles (F ¹ ) or to the at least one first material (F ² ). In the context of the present invention, "selectively" means that the corresponding functional group F ¹ or F ^{2 is} from 50 to 95%, preferably from 70 to 98%, particularly preferably from 80 to 98%, based on F ¹ , of the magnetic particles or , based on F ² , bind to the at least one first material, in each case in the presence of the at least one second substance, in each case based on all bonds between functional groups and components present in the mixture.

In a preferred embodiment, F ^{1 is} a functional group which selectively binds to the magnetic particles in the presence of silicates, more preferably selected from phosphonic acid group -OP (OH) ₂ or carboxylic acid group - COOH.

In a further preferred embodiment, F ^{2 is} a functional group which, in the presence of oxidic ores, for example those mentioned above, in particular SiO ₂ or albite, binds to the at least one first substance, more preferably selected from the group consisting of the group consisting of thiol group -SH, hydroxy group -OH, xanthogenate -OCSSH, thiolate -S ^" , dihydroxy group, with- For example, 1, 2-dihydroxy or 1, 3-dihydroxy group, a dithiol group, for example, 1, 2-dithiol or 1, 3-dithiol group, a thiohydroxy group, for example, 1, 2-thiohydroxy or 1, 3-thiohydroxy group, functional groups of the general formula (VIII) and mixtures thereof.

(VIII) wherein

Y independently of one another S, NH, O, preferably independently of one another S or O,

XN, P, CH ₂ , preferably N,

a, b, c, d independently of one another denote an integer from 1 to 6, preferably 1 or 2. The attachment of functional groups F ^{2 of} the general formula (VIII) to - (A) _n - takes place via the free bond to X.

Very particularly preferred functional groups F ^{2 of} the general formula (VIII) are selected from the group of the compounds of the formulas (Villa), (VIIIb), (VIIIc), (VIIId) and (VIIIc):

(Villa) (Vlllb) (Vlllc) (Vl lld) (Vllle) In the general formula (VII), A represents a structural unit selected from CRH ₂ group with R selected from hydrogen or linear or branched carbon radical having 1 to 30 carbon atoms, aromatic or heteroaromatic unit, cyclic or heterocyclic unit, unsaturated, branched or unbranched carbon chain with 2 to 30 carbon atoms, heteroatom or combinations of the abovementioned structural units, preferably CH ₂ group, wherein it is also possible according to the invention for -C double and / or triple bonds to be present in the skeleton of the bifunctional compounds formed by - (A) _n . Heteroatoms are, for example, O, S, N, and / or P. Suitable aromatic or heteroaromatic units are, for example, selected from substituted or unsubstituted aromatic or heteroaromatic units having 6 to 20 carbon and optionally heteroatoms, for example phenyl, benzyl and / or naphthyl. The aromatic moieties may be incorporated into the chain via the 1, 2-1, 3- and / or 1-4 positions.

In the compound of the general formula (VII), x and y describe the number of functional groups F ¹ or F ² present in the molecule. Preferably, x and y independently of one another are 1, 2 or 3, particularly preferably 1 or 2, very particularly preferably 1.

A very particularly preferred compound of the general formula (VII) is (2-mercapto-phenyl) -phosphonic acid

In a preferred embodiment of the method according to the invention, the functional group F ¹ in the compound of the general formula (VII) bind to the at least one magnetic particle and the functional group F ² in the compound of the general formula (VII) to the at least one first substance. After step (B) of the process according to the invention, in particular after carrying out the preferred embodiments B1, B2, B3, B4 or B5, in the dispersion are agglomerates of magnetic particles and the at least one first substance, the at least one second substance and optionally at least one third substance in front. This dispersion is preferably converted according to the invention directly into step (D). Step (C):

Step (C) of the process according to the invention comprises separating the investment product from the mixture from step (B) by applying a magnetic field gradient.

Suitable devices for magnetic separation according to step (C), preferably on an industrial scale, are known in the art.

Step (C) of the process of the present invention can be carried out in any of the apparatuses known and suitable to those skilled in the art, for example in a wet drum separator, high gradient magnetic separator or related apparatus. Step (C) of the process according to the invention may be carried out at any suitable temperature, for example 10 to 60 ° C.

In step (C), if appropriate, the adduct of step (B) may be separated by any method known to those skilled in the art.

Step (D):

Step (D) of the process of the invention comprises cleaving the separated addition product from step (C) to obtain the at least one first material and the magnetic particles separately.

The cleavage method used in step (D) of the method according to the invention is dependent on the method by which the agglomerates have been formed in step (B).

The cleavage may be by methods suitable for cleaving the adduct so that the magnetic particles can be recovered in reusable form. In a preferred embodiment, the magnetic particles, particularly preferably together with magnetic particles separated off in step (A), are used again in step (B).

In a preferred embodiment, the cleavage in step (E) of the process according to the invention is carried out by treatment of the adduct with a substance selected from the group consisting of organic solvents, basic compounds, acidic compounds, oxidizing agents, reducing agents, surface-active compounds and mixtures thereof.

Examples of suitable organic solvents are methanol, ethanol, propanol, for example n-propanol or isopropanol, aromatic solvents, for example benzene, toluene, xylenes, ethers, for example diethyl ether, methyl t-butyl ether, ketones, for example acetone, aromatic or aliphatic hydrocarbons, for example saturated hydrocarbons having, for example, 8 to 16 carbon atoms, for example dodecane and / or Shellsol®, diesel fuels and mixtures thereof. The main components of the diesel fuel are mainly alkanes, cycloalkanes and aromatic hydrocarbons having about 9 to 22 carbon atoms per molecule and a boiling range between 170 ° C and 390 ° C.

Examples of basic compounds which can be used according to the invention are aqueous solutions of basic compounds, for example aqueous solutions of alkali metal and / or alkaline earth metal hydroxides, for example KOH, NaOH, milk of lime, aqueous ammonia solutions, aqueous solutions of organic amines of the general formula R ² 3N, where R ^{2 is} independent is selected from the group consisting of CC ₈ alkyl, optionally substituted with further functional groups. In a preferred embodiment, step (E) is carried out by addition of aqueous NaOH solution up to a pH of 13, for example for the separation of OPS-modified Cu ₂ S. The acidic compounds can be mineral acids, for example HCl, H ₂ S0 ₄ , HNO ₃ or mixtures thereof, organic acids, for example carboxylic acids. As the oxidizing agent, for example H ₂ 0 ₂ can be used, for example as a 30 wt .-% aqueous solution (perhydrol). For the separation of thiol-modified Cu ₂ S is preferably H ₂ 0 ₂ or Na ₂ S ₂ 0 _{4 is} used.

Examples of surface-active compounds which can be used according to the invention are nonionic, anionic, cationic and / or zwitterionic surfactants.

In a preferred embodiment, the addition product of hydrophobic substance and magnetic particles is cleaved with an organic solvent, particularly preferably with acetone and / or diesel. This process can also be supported mechanically. In a preferred embodiment, ultrasound is used to assist the cleavage process.

In general, the organic solvent is used in an amount sufficient to cleave as much of the entire addition product as possible. In a preferred embodiment, 20 to 100 ml of the organic solvent is added per gram used as a cleavage product of hydrophobic material and magnetic particles.

In embodiment B3 of step (B) of the process according to the invention, in which the agglomeration takes place by means of polymeric compounds which have an LCST (Lower Critical Solution Temperature), the agglomerates can be separated in step (E) by setting a temperature in which the polymeric compounds have no hydrophobic character, so that the agglomerates are cleaved.

In embodiment B4 of step (B) of the process according to the invention, in which the agglomeration takes place by adjusting the pH of the resulting dispersion to a value at which the at least one first material and the magnetic particles bear opposite surface charges, the separation of the Agglomerates take place by adjusting a pH at which the at least one first material and the magnetic particles carry the same surface charges, so that the agglomerates are split.

According to the invention, after the cleavage according to step (D), the at least one first substance and the magnetic particles are present as dispersion either in said cleavage reagent, preferably an organic solvent, and / or in water.

In a preferred embodiment, the process according to the invention additionally comprises the following step (E):

(E) separating the magnetic particles from the mixture of step (D) to obtain the at least one first substance.

The magnetic particles may be separated from the dispersion containing these magnetic particles and the at least one first material by a permanent or switchable magnet from the solution. In a preferred embodiment, the separation in the optional step (E) is carried out analogously to step (C) of the method according to the invention. Individual process parameters, such as solids content, flow rate, can be changed as necessary in step (E).

After separation of the magnetic particles, the desired at least one first substance is present in a dispersion containing, where appropriate, a cleavage reagent and / or water. Preferably, the first substance to be separated off, preferably the metal compound to be separated off, is separated from the cleavage reagent, for example an organic solvent, for example by distilling off. The first substance obtainable in this way can be purified by further methods known to the person skilled in the art. The solvent can, if appropriate after purification, be recycled back to the process according to the invention. If, after separation of the magnetic particles, there is a dispersion of the at least one first substance in water, the water can likewise be removed by methods known to the person skilled in the art, for example distillation, filtration, decantation and / or centrifuging.

In the steps (A), (B), (C) (D) and / or optionally (E) according to the invention optionally further dispersing agent may be added to the present dispersion. In this case, further dispersant can be added according to the invention in order to obtain dispersions with lower solids contents in the individual steps.

As dispersing agents to be additionally added, all dispersing agents which have already been mentioned in relation to step (A), in particular water, are suitable.

The optional addition of dispersing agent can be carried out according to the invention by all methods known to the person skilled in the art.

The present invention also relates to a control and / or regulating device for a device for separating at least one first substance from a mixture containing this at least one first substance, at least one second substance and magnetic particles, with a machine-readable program code having control commands, which at the execution of the control and / or regulating device for performing the method according to the invention cause.

Claims

claims

1 . A method for separating at least a first substance from a mixture containing said at least one first substance, at least one second substance and magnetic particles, comprising the following steps: at least partial separation of the magnetic particles by applying a magnetic field gradient, optionally in the presence of at least one dispersant to obtain a mixture containing at least a first substance and at least one second substance and a reduced amount of magnetic particles,

Contacting the mixture comprising at least a first substance and at least one second substance from step (A) with magnetic particles so that the at least one first substance and the magnetic particles are deposited,

Separating the adduct from the mixture of step (B) by applying a magnetic field gradient and

Cleaving the separated adduct product from step (C) to separately obtain the at least one first material and the magnetic particles.

A method according to claim 1, characterized in that the first substance is a hydrophobic metal compound or carbon and the second material is a hydrophilic metal compound.

A method according to claim 2, characterized in that the at least one hydrophobic metal compound is selected from the group of sulfidic minerals, the oxidic and / or carbonate minerals.

A method according to claim 2, characterized in that the at least one hydrophilic metal compound is selected from the group consisting of oxidic and hydroxide metal compounds.

5. The method according to any one of claims 1 to 4, characterized in that in step (B) of the method according to the invention magnetic particles are used, selected from the group consisting of magnetic metals, for example iron, cobalt, nickel and mixtures thereof, ferromagnetic Alloys of magnetic metals, magnetic iron oxides, for example se magnetite, maghemite, pyrrhotite, ilmenite, other ferromagnetic minerals of the FeO-Fe ₂ O ₃ -TiO ₂ system, cubic ferrites of the general formula (I)

M ²⁺ _x Fe ²⁺ _1-x Fe ³⁺ ₂ 0 ₄ (I) with

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

x <1, hexagonal ferrites, for example barium or strontium ferrite MF when M = Mg, Ca, Sr, Ba, and mixtures thereof.

Method according to one of claims 1 to 5, characterized in that the magnetic particles used in step (B) are hydrophobized on the surface with at least one surface-active substance.

Method according to one of claims 1 to 6, characterized in that the in step (A) separated magnetic particles in step (B) are used.

8. The method according to any one of claims 1 to 7, characterized in that the dispersant is water.

Method according to one of claims 1 to 8, characterized in that additionally comprises the following step (E):

10. The method according to any one of claims 1 to 9, characterized in that the at least one substance and the magnetic particles in step (B) due to hydrophobic interactions, different surface charges and / or in the mixture of present compounds containing the at least one substance and the magnetic particles selectively couple, attach.

1 1. Method according to one of claims 1 to 10, characterized in that the mixture containing at least a first material and at least one second material before or during step (B) to particles with an average size of 100 nm to 100 μηη will be milled.

Control and / or regulating device for a device for separating at least one first substance from a mixture containing said at least one first substance, at least one second substance and magnetic particles, with a machine-readable program code having control commands, which in the execution of the control and or cause control device for performing the method according to any one of the preceding claims.