Punicin and its derivatives as collectors for flotation

Abstract

The present invention relates to the use of a compound as a collector for the selective flotation of lithium minerals, characterized in that the compound is represented by the formula (1): AB (1); wherein A is a) an aromatic group substituted by one or more OH and / or SH groups, or b) an aromatic group attached to B via a methylene group of the formula -[CH2]- or a methylene carbanion group of the formula -[CH -]-; wherein B is i) a pyridinium or benzoannelated pyridinium compound, wherein A is bonded to the nitrogen atom of the pyridinium or benzoannelated pyridinium compound, or ii) a substituted or unsubstituted pyridyl or benzoannelated pyridyl group; wherein the selective flotation of lithium minerals is carried out using a conditioning time CT ≥ 3 min, preferably > 5 min, more preferably > 10 min, and / or wherein the selective flotation of lithium minerals is carried out at a temperature ≤ 10°C or ≥ 25°C, preferably ≤ 5°C or ≥ 40°C. The present invention further relates to a flotation composition comprising said compound as a collector and a flotation process using said compound as a collector.

Description

The present invention relates to punicin and its derivatives which can be used as collectors for the selective flotation of minerals, in particular for the purpose of purification, such as the separation of desired minerals from gangue materials.Background ArtMany technical products of daily life contain a lot of valuable elements such as lithium, gold or the so-called critical raw elements, the natural resources of which are finite or which are not available, or not all available without restriction, for political reasons. For example, mobile telephones contain between 50 and 60 different elements which are disposed of in the worst case after their useful life.Today, the recycle rate for lithium or bismuth is almost 0%; it is about 1% for boron, 22% for cobalt and palladium, and low 28% for palladium. The development of effective recycling methods to recover these elements and establish a circular economy ("circulatory business") over a large area is therefore one of the great advances of our time. The different materials are not contained in different components of the disposed of technical devices in a single type, so that a purely mechanical separation after disassembly is not possible. Rather, complex material mixtures are to be found which, after a thermal treatment for burning organic constituents, require decomposition to ions or mechanical comminutions to particle sizes and compositions as defined as possible. The same applies to ores naturally occurring. The latter process generally involves flotation to separate the desired element or mixture of elements as particles from undesired material.Flotation is of great importance both in the recovery of elements from natural resources as a technique of mineral process technology and in recycling, in which, for example, artificially produced minerals from slags, produced by the thermal utilization of technical products, are used as a source of recyclable elements. Flotation is based on differences in the surface hydrophobicity of dispersed particles produced by grinding raw materials such as slags for the purpose of separating valuable components from useless particles ("gangue"). For flotation, the particles are mixed with water and subsequently conditioned with various reagents such as collectors ("collectors"), foaming agents ("foamers"), regulators etc. Blown air causes bubbling of hydrophobically treated particles which can thus rise and be separated off while non-hydrophobically treated particles remain in the dispersion. This is based on the separation effect for the raw material (recovery) of valuable particles from particles from useless gangue. The above-mentioned reagents affect various interactions of the particle surfaces with each other or with the air bubbles and determine physical parameters such as wettability or adsorption on the surface of the particles. Flotation is an old method for separating particles. Accordingly, a wide range of different collectors, foaming agents and other additives are available today for the different treatments. The technical literature also reveals novel flotation systems which are not yet in industrial use. Goals of optimizations are often to maximize the adsorption of collectors on the particle surface to increase hydrophobicity and thus particle-air bubble interactions.Given the complex compositions of the particles to be separated, especially from recycling, the selectivity of the process, which is constitutively related to the characteristics of the collectors, is, besides the overall yield, a major requirement of flotation. The selectivity of collectors is associated, inter alia, with their attachment to specific (desired) particles in these complex particle mixtures. This requires accumulators or systems of accumulators and the other reagents mentioned above, the properties of which can be adjusted to the specific separation problem. Up to now collectors or systems consist of collectors, foaming agents, additives, buffers, etc. of compounds, the properties of which can be adjusted to the respective separation problem, if need be, by changing the mixing ratios and / or the composition of the system per se. However, the system once selected is no longer adjustable with respect to properties. This leads to even small changes in the composition of a mixture to be separated leading to drastic losses in selectivity or yield and in each case requiring the development of new flotation systems from collectors, foaming agents, additives, buffers, etc. Consequently, the process engineering complexity can increase, since new flotation systems must be developed continuously.Against this background, there is a need for more universal flotation agents which can be adapted more easily to the separation problem of flotation. Specifically, it would be very advantageous if there were flotation means, for example collectors, which can be switched, i.e. the properties of which can be changed by the parameters of the flotation. Thus, the skilled person can conveniently adjust the flotation process from the outside depending on the separation problem by simply changing the pH of the flotation mixture and / or irradiating the flotation mixture with light to generate free radical species in situ (using specific light sources; or alternatively operating under exclusion of light) and / or adding agents which generate free radical species in situ. These radicals have interactions with the particles to be floated other than their non-radical precursors, so that the conditions can be tailored to the particular separation problem of valuable and non-valuable particles.An example known in the prior art which has not been used for flotation yet but has switching ability is called punicin.Schmidt et al. ["Studies on photocatalytically active materials containing structure elements of a pyridinium alkaloid from Punica garnet", Journal of Materials Chemistry 2007, 17, 2793-2800.] discloses the physicochemical properties and the photocatalytic switchability of punicin.Albrecht et al. ["Redox active donor-substituted punicin derivatives", Organic & Biomolecular Chemistry 2009, 7, 1445-1453.] discloses punicin and punicin derivatives including their donor and acceptor properties and their photocatalytic activity.Nagoriny et al. ["Switchable Mesomeric Betaines Derived from Pyridinium Phenates and Bis(thienyl)ethane", European Journal of Organic Chemistry 2021, 3178-3189.] discloses the photocatalytic switchability of punicin and punicin derivatives in combination with color changes.Qiu et al. ["Improvement of the Fresh Flotation of LiAlO2and melilite solid solution via pre-functionalization", Scientific Reports 2021, 11, 20443.] and Qiu et al. ["Influencing the Fresh Flotation of LiAlO2and melilite solid solution with ionic liquids", RSC Advances 2022, 12, 29562-29568.] disclose flotation of LiAlO2and gehlenite in Hallmond tubes, wherein the experimental method comprises adjusting and stabilizing the pH and pre-functionalizing the particles by chemical reactions but no switchable molecules.SUMMARY OF THE INVENTIONThe present inventors have surprisingly found that switchable compounds can be used advantageously for flotation purification processes, since the light source for generating radical species, the absence of light to prevent their formation or the addition of radical-forming additives affect the results of flotation. To the knowledge of the inventors, switchable collectors or other switchable additives for flotation in general, in particular based on punicin or its derivatives and similar compounds such as pyridiniumylidene, are not yet known, as are the use of different light sources in flotation. Therefore, the concept of switchable collectors for flotation has been developed by the inventors of the present invention.An example of a compound having the advantageous switchable properties is punicin (N-(2',5'-dihydroxyphenyl)pyridinium), which in one of its zwitterionic tautomeric forms has the following formula: Although known for some time, this natural product 2005 has been further studied and, according to its origin, called "punicin". Inter alia, its properties under the influence of various pH values, its pH switchability, have been investigated [A. Schmidt, T. Mordhorst, M. Nieger, "Investigation of a betaine alkaloid from Punica garnet", Natural Product Research 2005, 19, 541-546]. Accordingly, punicin is present in acids as cation, but in the neutral in the form of two betaines (zwitterions), which differ as tautomers in their conjugation type. Punicin is completely deprotonated in the basic and is thus present as an anion (see FIG. 1 ). Under the influence of strong bases, a ring opening finally takes place with formation of a 2-fold negatively charged species, a dianion. This reaction or the deprotonations are reversible; the cation is reconstituted in acid.Furthermore, punicin has radical constituents which form in particular in light. Depending on the substitution pattern on the punicin in the form of its derivatives or on the attachment of punicin derivatives to polymers, the free radicals formed are stable ("persistent free radicals"). The process of radical formation is also reversible. Thus, punicins and punicin derivatives are molecules reversibly switchable by pH, light or additives. Furthermore, punicins are robust, stable and can be produced inexpensively in large quantities. Moreover, they can be structurally varied in a simple manner and can thus be functionalized and tailored in terms of their switchability (see FIG. 2 ). Examples of the preparation of punicin derivatives have been published, inter alia, in the following documents:A. Schmidt, T. Mordhorst, "Conjugated, cross-conjugated, and pseudo-cross-conjugated derivatives of a pyridinium alkaloid from Punica garnetum", ARKIVOC 2003, XIV, 233-245;A. Schmidt, T. Mordhorst, H. Fleischhauer, G. Jeschke, "Coupled photocatalytic electron-transfers with 4,4'-bipyridinium derivatives of a betaine alkaloid from Punica garnetum", ARKIVOC 2005, X, 150-164;H. Fleischhauer, L. Frormann, A. Schmidt, "Von Vegetal Ingredient zur Polymer-Neufeitung des Prufberpier der Naturbeit", Extrusion 2005, 5, 50-51;A. Schmidt, M. Albrecht, T. Mordhorst, M. Topp, G. Jeschke, "Studies on photocatalytically active materials containing structure elements of a pyridinium alkaloid from Punica garnet", Journal of Materials Chemistry 2007, 17, 2793-2800;A. Schmidt, M. Topp, M. Mordhorst, O. Schneider, "Redox active derivatives of the betaine-alkaloid Punicine from Punica garnet", Tetrahedron 2007, 63, 1842-1848;A. Schmidt, M. Albrecht, "Photocatalytically Active Materials with Pyridinium enolate Partial Structures", journal for Natural Research 2008, 63b, 465-472;M. Albrecht, O. Schneider, A. Schmidt, "Redox-active donor-substituted punicin derivatives", Organic and Bio molecular Chemistry 2009, 7, 1445-1453;M. Albrecht, M. Yulikov, T. Kohn, G. Jeschke, J. Adams, A. Schmidt, "Pyridinium salts and ylides as partial structures of photoresponsive Merrifield resins", Journal of Materials Chemistry 2010, 20, 3025-3034;M. Albrecht, M. Gjikaj, A. Schmidt, "Intermolecular interactions of punicin derivatives", Tetrahedron 2010, 66, 7149-7154;C. F. Otto, C. Herzberger, M. Liu, J. C. Namyslo, M. Nieger, T. Frese, F.Lederle, E. G. Hübner, A. Schmidt, "Borane adducts of punicine and of its dehydroxy derivatives (pyridinium 1-yl)-2-and 3-phenates", Tetrahedron 2020, 76, 131627.In continuation of these work, the inventors found that (hetearenium)-ylides are switchable in a similar manner. In such ylidene, the phenolate radical of punicin is formally replaced by a carbanion (see FIG. 3 ). The switchability of such ylides is based on similar principles to those described for punicin: a pyridinium salt (or more generally "hetearenium salt") can be cleaved off from a proton in the α position to the nitrogen atom (see FIG. 4 ). The ylide formed (a special form of zwitterion) can delocalize both charges and is therefore stabilized. Under the influence of light or upon addition of suitable additives, they form either radical anions and radical cations or, within a single molecule, a diradical. The formation of radical species from suitable ylidene precursors is manifested in sunlight by an intense blue coloration of the materials which spontaneously disappears again when the light intensity is reduced (for example under "cloudy" conditions).The present invention is therefore directed to the use of a compound as collector for the selective flotation of lithium minerals, characterized in that the compound is represented by formula (1): wherein Aa) is an aromatic group substituted by one or more OH and / or SH groups, orb) is an aromatic group attached to B via a methylene group of formula -[CH 2]- or a methylene carbanion group of formula -[CH -]- ; wherein Bi) is a pyridinium or benzo-fused pyridinium compound, wherein A is attached to the nitrogen atom of the pyridinium or benzo-fused pyridinium compound, orii) is a substituted or unsubstituted pyridyl or benzoannellated pyridyl group; wherein the selective flotation of lithium minerals is carried out using a conditioning time CT≥3 min, preferably >5 min, further preferably >10 min, and / or wherein the selective flotation of lithium minerals is carried out at a temperature ≤ 10° C. or ≥ 25° C., preferably ≤ 5° C. or ≥ 40° C.In one embodiment, the compound has the structure of natural punicin (N-(2',5'-dihydroxyphenyl)pyridinium) having one or more additional substituents on A or B of formula (1), e.g., substituted or unsubstituted C1-C20hydrocarbons and the specific substituents disclosed herein for R 1- R 9.The present invention is further directed to a flotation composition comprising the collector defined herein.The present invention is further directed to a flotation process comprising the steps of: a) providing a suspension of a mixture of at least two types of particulate materials in a solvent, preferably water; b) combining the flotation composition defined herein with the suspension of step a), optionally adjusting the temperature to a conditioning temperature; c) conditioning the mixture of step b) for the duration of a conditioning time to form one or more types of particulate materials on the surface of which at least a portion of the collector comprised of the flotation composition defined herein is enriched; d) adjusting the mixture of step c) to a (flotation) temperature; e) introducing a flotation gas for forming a flotation foam at the surface of the solvent, wherein the flotation foam comprises a part of the particulate materials to be separated from the remaining part of the particulate materials, f) separating the flotation foam from the suspension; wherein the particulate materials comprise lithium minerals and gangue materials; preferably wherein the selective flotation of lithium minerals is carried out using a conditioning time CT ≥ 3 min, preferably > 5 min, further preferably > 10 min, and / or wherein the selective flotation of lithium minerals is carried out at a temperature ≤ 10° C. or ≥ 25° C., preferably ≤ 5° C. or ≥ 40° C.DETAILED DESCRIPTION OF THE INVENTIONThe present invention relates to the use of a compound as collector for the selective flotation of minerals, preferably lithium minerals, or, in other words, a flotation process using a compound as collector for the selective flotation of minerals, preferably lithium minerals, characterized in that the compound is represented by formula (1): wherein Aa) is an aromatic group substituted by one or more OH and / or SH groups, orb) is an aromatic group attached to B via a methylene group of formula -[CH 2]- or a methylene carbanion group of formula -[CH -]- ; wherein Bi) is a pyridinium or benzo-fused pyridinium compound, wherein A is attached to the nitrogen atom of the pyridinium or benzo-fused pyridinium compound, orii) is a substituted or unsubstituted pyridyl or benzoannelized pyridyl group; preferably wherein the selective flotation of lithium minerals is carried out using a conditioning time CT≥3 min, preferably >5 min, further preferably >10 min, and, for example, up to 24 hours; and / or wherein the selective flotation of lithium minerals is carried out at a temperature, wherein the temperature is the temperature of the flotation suspension / mixture (to be floated), of ≤ 10°C or ≥ 25°C, preferably ≤ 5°C or ≥ 40°C.The above-described use / method is not limited to lithium minerals, but may also be applied to other minerals described herein.In the last step of the selective flotation process, a purified lithium mineral / purified lithium minerals is / are obtained. Impurities (which do not interact with the compound) are separated.In one embodiment, the conditioning time CTis 5 minutes or more.In one embodiment, the conditioning time CTis 10 minutes or more.In one embodiment, the conditioning time CTis 60 minutes or more.In one embodiment, the conditioning time CTis 120 minutes or more.In one embodiment, the selective flotation of lithium minerals is carried out at a temperature of 1° C. or ≥40° C., preferably at a temperature of 1° C. or ≥50° C.In one embodiment, the compound represented by formula (1) is not a natural punicin, i.e., is not In one embodiment, the aromatic group substituted with one or more OH and / or SH groups is further substituted with at least one group selected from the group consisting of: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, SC(S)N(R L) R k, NH-OH, Copperrone and guanidine, wherein R k and R L are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk and RL optionally together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, preferably the aromatic group is further substituted with at least one group selected from the group consisting of: OH and Br.In one embodiment, the aromatic group attached to B via a methylene group of formula -[CH2]- or a methylene carbanion group of formula -[CH-]- is further substituted with at least one group selected from the group consisting of: H, OH, NH 2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halo, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, os(o)_ner32_R k, OS(O)OR k, OS(O) 2 R k, OR k, N(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, oc(o)R k, OC(O)R k, OC(O)OR k, and OC(O)N(R k) R L, preferably further substituted with at least one group selected from the group consisting of: H, C 1-12- hydrocarbon group, acyl group with a C1-12hydrocarbon group, halogen, preferably R 11, R 12 are independently selected from: H, methyl, tert-butyl group, COMe, unsubstituted C 10- alkyl, and hex-1-enyl, Cl wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups.In one embodiment, the aromatic group substituted with one or more OH and / or SH groups is further substituted with at least one group selected from the group consisting of: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, preferably Br, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 ORk, OS(O)Rk, OS(O)2Rk, os(o)or_ner87_, os(o)_ner88_R k, OR k, N(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( OR L), SiR k R L Rm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, oc(o)R k, OC(O)OR k, and OC(O)N(R k) R L, wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups; and wherein any other substituent of the aromatic group is selected from the group consisting of:H, OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORk, n(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( OR L), SiR k R L R m, C(O)R k, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, OC(O)Rk, OC(O)ORk, oc(o)n(R k) R L wherein R k, R L and R m are as defined above.In one embodiment, the aromatic group substituted with one or more OH and / or SH groups is substituted with an OH or SH group and with a group selected from the group consisting of: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH ), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, copperrone and guanidine, wherein R k and R L are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k and R L optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, preferably with a group selected from the group consisting of: OH and Br; further preferably any other substituent of the aromatic group is then selected from the group consisting of:H, OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORk, n(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( OR L), SiR k R L R m, C(O)R k, C(O)ORk, C(O)N(R)Rk, OC(O)Rk, OC(O)Rk, OC(O)OR, oc(o)n(R k) R L, wherein R k, R L and R m are as defined above.In one embodiment, the aromatic group substituted with one or more OH and / or SH groups is substituted with an OH or SH group and is substituted with a group selected from the group consisting of: NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, SC(S)N(R L) R k, NH-OH, Copperrone and guanidine, and halogen, preferably F, Cl, Br, I, particularly preferably Br, wherein R k and R L are independently selected from H and substituted or unsubstituted C 1-25- alkyl or C 1-25 alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein one or more of R k and R L optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups; wherein the one OH or SH group is in the para position to the group selected from the group consisting of: NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, sc(o)n(R L) R k, SC(S)N(R L) R k, NH-OH, Copperrone, and guanidine, and halogen, preferably F, Cl, Br, I, more preferably Br; further preferably wherein any other substituent of the aromatic group is then selected from the group consisting of: H, NH 2, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, s(o)_ner250_R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 R k, OS(O)OR k, OS(O) 2 R k, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, OC(O)N(Rk)RL, wherein Rk, RL and Rm are as defined above.In one embodiment, the aromatic group substituted with one or more OH and / or SH groups is based on benzene.In one embodiment, the aromatic group attached to B via a methylene group of formula -[CH 2]- or a methylene carbanion group of formula -[CH -]- is substituted with one or more group selected from the group consisting of: OH, NO 2, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, preferably F, Cl, Br, I, more preferably Br, R k, SR k, S(O)H, S(O)R k, S(O) 2 H, s(o)_ner293_R k, S(O)OH, S(O)OR k, S(O) 2 OH, S(O) 2 OR k, OS(O)H, OS(O)R k, OS(O) 2 H, OS(O) 2 R k, OS(O)OH, OS(O)OR k, OS(O)2H, OS(O)2Rk, ORk, NH(Rk), n(R k)( R L), P(O)(OH) 2, P(O)(OR k)( OH), P(O)(OR k)( OR L), OP(O)(OH) 2, OP(O)(OR k)( OH), OP(O)(OR k)( OR L), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(H)Rk, c(o)n(R L) R k, OC(O)R k, OC(O)OR k, OC(O)N(R k) H, OC(O)N(R k) R L, where R k, R L and R m are selected independently of one another from H and substituted or unsubstituted C1-25alkyl- or C1-25alkenyl-, substituted or unsubstituted C1-25heteroalkyl-, A substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl group, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, the aromatic group attached to B via a methylene group of formula -[CH 2]- or a methylene carbanion group of formula -[CH -]- is substituted with a group selected from the group consisting of: NO 2, halogen, preferably Cl, R k, OR k, N(R k)( R L), C(O)R k, C(O)OR k, C(O)N(H)R k, C(O)N(RL)Rk, oc(o)R k, wherein R k and R L are independently selected from substituted or unsubstituted C 1-25- alkyl or C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, the aromatic group attached to B via a methylene group of formula -[CH 2]- or a methylene carbanion group of formula -[CH -]- is substituted with a group selected from the group consisting of: NO 2, halogen, preferably Cl, R k, C(O)R k, wherein R k is independently selected from substituted or unsubstituted C 1-25- alkyl or C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, A substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl group, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups; further preferably wherein R k is selected from substituted or unsubstituted C 1-25- alkyl or C 1-25- alkenyl.In one embodiment, the pyridinium or benzo-fused pyridinium compound is substituted with a group selected from the group consisting of: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 ORk, OS(O)Rk, OS(O)2Rk, os(o)or_ner403_, os(o)_ner404_R k, OR k, N(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( OR L), SiR k R L Rm, C(O)Rk, C(O)ORL, C(O)N(R_NER #1_)RL, OC(O)R_NER #1_, oc(o)R k, OC(O)OR k, and OC(O)N(R k) R L, wherein R k, R L and R m are independently selected from substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, the pyridinium or benzoannellated pyridinium compound is substituted with a group selected from the group consisting of:H, C1-12hydrocarbon group, acyl group with a C1-12hydrocarbon group, halogen, substituted or unsubstituted C 1-25- heteroalkyl groups, C(O)N(R k)( R L), preferably R 11, R 12 are independently selected from: H, methyl, tert-butyl group, C(O)Me, unsubstituted C 10 alkyl, and hex-1-enyl, Cl, C(O)N(H)(hexyl), hexadecyl-4'-pyridinium,where R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, where two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, the pyridinium or benzo-fused pyridinium compound is substituted with a group selected from the group consisting of: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 ORk, OS(O)Rk, OS(O)2Rk, os(o)or_ner471_, os(o)_ner472_R k, OR k, N(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( OR L), SiR k R L Rm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, oc(o)R k, OC(O)OR k, and OC(O)N(R k) R L, where R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, the pyridinium or benzoannellated pyridinium compound is substituted with a group selected from the group consisting of:halogen, preferably Cl, R k, C(O)R k,where R k is selected from substituted or unsubstituted C 1-25- alkyl or C 1-25- alkenyl, preferably methyl, ethyl, t-butyl, unsubstituted C 6-19 alkyl, unsubstituted C 6-19 alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, preferably pyridin-4-yl, pyridin-3-yl, pyridin-2-yl, pyridinium-1-yl, wherein one or more of R k and R L optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.Flotation is a physical separation process for separating various types of solid materials, e.g. for separating mixtures of particulate solids of various materials, e.g. ores and gangue materials, in an aqueous slurry or suspension using air bubbles, utilising the different surface wettability of the various particles contained in the suspension. Flotation is used for the treatment of mineral raw materials and for the processing of preferably mineral substances which contain small to average amounts of a desired component or a valuable material, for example in the form of non-ferrous metals, iron, rare earth metals and / or noble metals and nonmetallic mineral raw materials. However, the use of flotation is also generally known in other technical fields, such as, for example, waste water treatment.The term "selective flotation" as used herein refers to a flotation process in which at least two types of particulate materials, such as at least one naturally occurring or man-made mineral of commercial interest (to be purified) and at least one feed material (a contaminant not of commercial interest) are to be separated. That is, at least one contaminant / gangue must be removed, preferably two or more, most preferably all gangue materials are removed from the mixture of particulate materials.The number of the various kinds of particulate materials (e.g., a desired metal oxide and a silicate material as an undesirable gangue / impurity) is at least 2, e.g., 2-20 or 4-20.One type of particulate material may be a pure chemical substance such as LiAlO2or a mixture of different substances in a particle. The flotation of the present invention can be used to separate particles of pure chemical substances or particles containing a mixture of chemical substances. For example, it is possible to separate particles having a certain content of a chemical substance from particles having lower contents of the chemical substance or another composition.As used herein, the term "mineral" (sometimes referred to as "ore") refers to a substance or mixture of substances that are solid inorganic materials, particularly solid inorganic materials that contain one or more metals and preferably additionally oxygen, i.e., oxides of one or more metals. These can either occur naturally, arise during recycling processes or be produced artificially and ideally be represented by a chemical formula which is generally abiogenic and can have an ordered atomic structure. The "mineral" is the product to be purified by flotation. The minerals may be selected from the group of minerals containing lithium, copper, cobalt, manganese, gallium, niobium, tantalum, platinum group element and rare earth metal, preferably lithium aluminate, spodumene, chalcopyrite, monazite, galaxite, lithium carbonate, lithium oxide and combinations thereof. The ore mineral is distinct from a rock which may be an aggregate of minerals and / or non-minerals. Examples of minerals include sulfides, oxides, halides, carbonates, sulfates and phosphates of valuable metals. The term "mineral" is not limited to materials derived from mining, but includes minerals and salts from any other source, such as from recycling processes of batteries such as lithium batteries.The particulate solids of the various materials to be separated by the method of the invention may be fine-grained, e.g. having a particle size within 5μm - 500μm, which may be determined e.g. by the use of a volumetric dynamic laser light scattering method, preferably by the use of an instrument from Malvern Instruments, Ltd., Malvern, United Kingdom, preferably a Mastersizer.Preferably, the purity level of a type of particulate material provided by the process (when assuming a lower purity level in the suspension) is at least 80% or at least 90%, preferably at least 95% or at least 98% or even 100%. The purity level can be determined by standard measurements such as ICP-OES (atomic emission spectroscopy with inductively coupled plasma).As used herein, "switchable" refers to compounds whose properties can be altered by the environment (i.e., external parameters), e.g., by changing pH, changing oxidation state, temperature, and irradiating with light. In this context, "switching the collector" or "switching the collector" means stimulating the collector, e.g., by light irradiation / exclusion and / or by pH change, thereby changing the properties of the collector to change the selectivity of the collector to one or more specific particulate materials.By using switchable compounds, the skilled person can easily adjust the parameters of the flotation process to meet the requirements for the purification of the desired minerals. Depending on the requirements for the separation, the flotation conditions and properties of the collector compounds can be adjusted, for example, by changing the pH of the flotation mixture and / or by irradiating the flotation mixture with light (using specific light sources or alternatively with exclusion of light).In one embodiment, lithium minerals such as lithium aluminate as an man-made mineral produced during the recycling of lithium batteries may be separated from contaminants such as gehlenite, which is an undesirable gangue in these processes.The term "gait(art)" refers to that portion of the material which is of little or no value (i.e., the contaminant) and which must be separated from the materials such as the minerals. Examples of gangue materials include, but are not limited to, silicate minerals, preferably selected from the group consisting of gehlenite, pyrite, zinc blende, galenite, and combinations thereof.As used herein, the term "collector" refers to a compound that selectively forms a hydrophobic layer on a particular valuable material that contains material such as a mineral surface. Collectors are generally known for their use in flotation processes.As used herein, the term "aromatic group" refers to groups having aromaticity, i.e., having a conjugated ring of unsaturated bonds or ion pairs of electrons, that satisfy the Hückel rule, which states that an aromatic system should have 4n+2n electrons, where n is an integer ≥ 0. This aromatic group includes aryl and heteroaryl groups. The aromatic group may be substituted or unsubstituted. The aromatic group includes both aromatic hydrocarbon groups having a ring and polycyclic aromatic ring systems. The polycyclic rings may have two or more rings in which two carbons are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is an aromatic hydrocarbon group, e.g., the other rings may be cycloalkylene, cycloalkenyl, aryl, heterocycles and / or heteroaryls.As used herein, the term "methylene" refers to a divalent -CH 2- group present in an alkyl or alkylene group.The term "carbanion" refers to a trivalent carbon atom bearing a formal negative charge as the open valence position.The term "substituted" in reference to groups such as electron donating or alkyl / alkene / alkyne groups as used herein refers to groups wherein one or more hydrogen atoms are replaced by various atoms or groups such as halogens (e.g., Cl, Br, I, F), amines (primary, secondary, tertiary), sulfates, phosphates, ethers, esters, OH, SH, CF 3, CN, (unsubstituted) C 1-4- alkyl, C 1-4- heteroalkyl, C 6-14- aryl, and C 4-12- heteroaryl groups, etc.The term "unsubstituted" in reference to groups such as electron donating or alkyl / alkene / alkyne groups as used herein refers to groups wherein no hydrogen is replaced by another atom or group. That is, the term unsubstituted alkyls as used herein includes methyl, ethyl, propyl, etc.It is noted that not all hydrogen atoms are indicated in the formulas of the application. Moreover, each atom in the general formulae may be replaced by one of its isotopes. That is, each hydrogen atom may be replaced with deuterium D.Furthermore, any carbon atom in the isolated and / or classified compounds can be substituted (partially or fully) by any of its isotopes, more preferably 13 C. Furthermore, any nitrogen atoms in the isolated and / or classified compounds can be substituted (partially or fully) by 15 N. Furthermore, any oxygen atoms in the disclosed and / or laminated compounds can be substituted (partially or fully) by 17 O. Furthermore, any phosphorus atom in the isolated and / or classified compounds can be substituted (partially or fully) by 31 P.As used herein, the term "pyridinium" refers to the cationic form of pyridine.The term "annealed" means that a ring system is annealed either with another ring at the carbon atoms of the ring system or through a bond of the ring system, as is the case with fused or spiro ring systems.The term "bound" refers to at least one of the following bonds: covalent bonding, hydrogen bonding, ionic bonding, van der Waals interaction, pi interaction, London forces, or electrostatic interaction.As used herein, the term "pyridyl" (also called "pyridinyl") refers to a six membered aromatic heterocycle having a ring nitrogen atom and includes pyridin-2-yl, pyridin-3-yl, and pyridin-4-yl (also called 2-pyridyl, 3-pyridyl, and 4-pyridyl).According to a preferred embodiment of the present invention, the lithium minerals are selected from the group consisting of lithium aluminate, spodumene, chalcopyrite, monazite, galaxite, lithium carbonate, lithium oxide and combinations thereof.According to a preferred embodiment of the present invention, the selective flotation of lithium minerals is carried out at a pH>7, preferably at a pH below 10.According to a preferred embodiment of the present invention, A is represented by formula (2) or (3): ; wherein the dashed line represents the bond to B; wherein R 1 is selected from: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, copperrone and guanidine, wherein R k and R L are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k and R L optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, preferably R 1 is selected from: OH and Br; wherein R 2, R 3, R 4, R 5, R 6, R7, R9, R9are independently selected from the group consisting of: OH, NH2, SH, cf_ner560_, cn, c(o)nh_ner561_, c(o)h, c(o)oh, halogen, preferably Br, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 Rk, OS(O)ORk, OS(O)2Rk, ORk, n(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( OR L), SiR k R L R m, C(O)R k, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, OC(O)Rk, OC(O)ORk, and OC(O)N(R k) R L, where R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, where two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups; wherein R 10= -[ CH 2]- or R 10= -[ CH -]-; and / or wherein B is represented by formula (4) or (5): ; wherein the dashed line represents the bond to A; wherein R 11, R12, R13, R14, R15, R 16, R 17, R 18, R 19 are independently selected from: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, S(O)2R_NER628, S(O)OR_NER629, S(O)ORk, OS(O)Rk, os(o)_ner633_R k, OS(O)OR k, OS(O) 2 R k, OR k, N(R k)( R L), P(O)(OR k)( OR L), OP(O)(OR k)( ORL), SiRkRLRm, C(O)Rk, C(O)ORk, c(o)n(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(R k) R L, preferably R 11, R 12 are independently selected from: H, C1-12hydrocarbon group, acyl group with a C1-12hydrocarbon group, halogen, substituted or unsubstituted C 4-12- heteroaryl groups, C(O)N(R k)( R L), particularly preferably R 11, R 12 are selected independently of one another from: H, methyl, tert-butyl group, C(O)Me, unsubstituted C 10- alkyl, and hex-1-enyl, Cl, C(O)N(H)(hexyl), hexadecyl-4'-pyridinium, where R k, R L and R m are selected independently of one another from H and substituted or unsubstituted C 1-25- alkyl, A substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl group, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, R is 1 OH, or SH.In one embodiment, R is 1 OH.In one embodiment, at least one of R 2, R 3, R 4 is not H.In one embodiment, at least two of R 2, R 3, R 4 are not H.In one embodiment, R is 1 OH or SH, and / or R is 2 OH or SH.In one embodiment, R is 1 OH, and / or R is 2 OH.In one embodiment, R is 1 OH or SH, and / or R is 2 OH or SH, at least one of R is 3, R is 4 is not H.In one embodiment, R is 1 OH, and / or R is 2 OH, at least one of R is 3, R is 4 is not H.In one embodiment, R is 2, R is 3, R is 4 OH or halogen, preferably Br.In one embodiment, R is 1 OH and R is 2, R is 3, R is 4 OH or halogen, preferably Br.In one embodiment, at least one of R 11, R 12, R 13, R 14, R15is not H, or at least one of R 16, R 17, R 18, R 19 is not H.In one embodiment, R is 12 selected from the group consisting of:C1-12 hydrocarbon group, acyl group with a C1-12 hydrocarbon group, halogen, substituted or unsubstituted C 4-12- heteroaryl groups, C(O)N(R k)( R L), preferably R 12 is independently selected from the group consisting of: methyl, tert-butyl group, C(O)Me, unsubstituted C 10- alkyl, and hex-1-enyl, Cl, C(O)N(H)(hexyl), hexadecyl-4'-pyridinium, wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups.In one embodiment, R 11 is selected from the group consisting of: C1-12hydrocarbon group, acyl group with a C1-12hydrocarbon group, halogen, substituted or unsubstituted C 4-12- heteroaryl groups, C(O)N(R k)( R L), preferably R 11 is independently selected from the group consisting of: methyl, tert-butyl group, C(O)Me, unsubstituted C 10- alkyl, and hex-1-enyl, Cl, C(O)N(H)(hexyl), hexadecyl-4'-pyridinium, where R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, where two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, R 12 and / or R 11 are independently selected from the group consisting of:C1-12 hydrocarbon group, acyl group with a C1-12 hydrocarbon group, halogen, substituted or unsubstituted C 4-12- heteroaryl groups, C(O)N(R k)( R L), preferably R 11 is independently selected from the group consisting of: methyl, tert-butyl group, C(O)Me, unsubstituted C 10- alkyl, and hex-1-enyl, Cl, C(O)N(H)(hexyl), hexadecyl-4'-pyridinium,where R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl-, substituted or unsubstituted C 1-25- alkenyl-, substituted or unsubstituted C 1-25- heteroalkyl-, substituted or unsubstituted C 6-14- aryl- or substituted or unsubstitutedC 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.In one embodiment, R 1 is selected from the group consisting of: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH ), OC(S)SH, OP(S)(OH)SH, OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, SC(S)N(R L) R k, NH-OH, Copperrone, and guanidine, where R k and R L are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, where two or more of R k and R L optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, Preferably, R is 1 selected from: OH and Br; and at least one of R 11, R 12, R 13, R 14, R 15 is not H, or at least one of R 16, R 17, R 18, R 19 is not H.According to a preferred embodiment of the present invention, the compound used as collector for the selective flotation of lithium minerals is represented by formula (6) or formula (7): wherein R 1 is selected from: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, Copperron and guanidine, preferably R 1 is selected from: OH and Br; wherein R 2, R 3, R 4, R 5, R 6, R 7, R 8, are independently selected from the group consisting of: OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, preferably Br, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 Rk, OS(O)ORk, OS(O)2Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), op(o)(or_ner840_)(or_ner841_), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, preferably R2, R 3, R 4 are selected from the group consisting of: H, OH, Br; wherein R 10= -[ CH 2]- or R 10= -[ CH -]-; wherein R 11, R 12, R 13, R 14, R_NER865 are independently selected from: OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 Rk, OS(O)ORk, OS(O)2Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), op(o)(or_ner88_)(or_ner889_), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, preferably R11, R 12 are independently selected from: H, C 1-12- hydrocarbon group, acyl group with a C 1-12- hydrocarbon group, halogen, preferably R 11, R 12 are independently selected from: H, methyl, tert-butyl group, COMe, unsubstituted C 10- alkyl, and hex-1-enyl, Cl wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C_NER9 heteroalkyl, A substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl group, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groupsAccording to a preferred embodiment of the present invention, the compound used as collector for the selective flotation of lithium minerals is represented by formula (7): wherein R 1 is selected from: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, Copperron, and guanidine, preferably R 1 is selected from: OH and Br; wherein R 2, R 3, R 4 are independently selected from the group consisting of: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, preferably Br, R k, SRk, S(O)Rk, s(o)_ner941_R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 R k, OS(O)OR k, OS(O) 2 R k, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(OR), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL are preferred R2, R3, R 4 independently of one another selected from the group consisting of: H, OH, Br; wherein R 11, R 12, R 13, R 14, R 15 independently of one another are selected from: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SRk, S(O)Rk, S(O)2Rk, s(o)or_ner987_, s(o)_ner988_or_ner989_, os(o)r k, OS(O) 2 R k, OS(O)OR k, OS(O) 2 R k, OR k, N(R k)( R L), P(O)(OR k)( ORL), OP(O)(ORk)(ORL), SiRkRLRLRm, c(o)Rk C(O)ORk C(O)N(RL)Rk OC(O)Rk OC(O)Rk OC(O)ORk and OC(O)N(Rk)RL preferably R_NER1015, R_NER1016 are independently selected from: H, C_NER1017 hydrocarbon group, acyl group with a C_NER1018 hydrocarbon group, halogen, R11, R12 are preferably independently selected from: H, methyl, tert-butyl group, COMe, unsubstituted C10alkyl, and hex-1-enyl, Cl wherein Rk, RLand Rm are independently selected from H and substituted or unsubstituted C1-25alkyl, substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, RLand Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups.According to a preferred embodiment of the present invention, the compound used as collector for selective flotation of lithium minerals is represented by formula (9) or by formula (10): ; wherein R2, R3, R4 are independently selected from the group consisting of: OH, NH2, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, Rk, SRk, S(O)Rk, s(o)_ner1044_Rk, S(O)ORk, S(O)2ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk C(O)ORk C(O)N(RL)Rk OC(O)Rk OC(O)Rk OC(O)ORk and OC(O)N(Rk)RL preferably one of R2, R3, R4H, preferably, two of R2, R3, R4H are two; further preferably, R2, R3, R4H are selected independently from each other from: OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, Rk, sr_ner1092_, s(o)Rk, S(O)2Rk, S(O)ORk, S(O)2ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORL, N(Rk)(RL), P(O)(ORk)(ORL), op(o)(or_ner1110_)(or_ner1111_), SiRkRLRm C(O)Rk C(O)ORk C(O)N(RL)Rk OC(O)Rk OC(O)Rk OC(O)ORk and OC(O)N(Rk)RL preferably R11, R12 are independently selected from: H, C1-12 hydrocarbon group, acyl group having a C1-12 hydrocarbon group, halogen, particularly preferably R11, R12 are independently selected from: H, methyl, tert-butyl group, COMe, unsubstituted C10 alkyl, and hex-1-enyl, Cl are preferably R13, R14, R15H ; wherein R20, R21, R22independently of one another selected from the group consisting of: OH, NH, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, preferably Br, Rk, SRk, S(O)Rk, S(O)2Rk, S(O)ORk, S(O)2ORk OS(O)Rk OS(O)2Rk OS(O)ORk, os(o)_ner1152_Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, oc(o)Rk OC(O)ORk and OC(O)N(Rk)RL are preferably R20, R21, R22 independently of one another selected from the group consisting of: OH and Br, particularly preferably R20Br and R21, R_NER1178 are OH; wherein R23, R24, R25, R26, R27independently of one another selected from the group consisting of: OH, NH2, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, Rk, SRk, S(O)Rk S(O)2Rk S(O)ORk S(O)2ORk OS(O)Rk OS(O)2Rk OS(O)ORk, os(o)_ner1199_Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, oc(o)Rk OC(O)ORk and OC(O)N(Rk)RL are preferred, and are R23, R24, R25, R26, R27Rk ; Particular preference is given to R24Alkyl and preference is furthermore given to R24methyl and R23, R25, R26, Rare H; where R, RLand Rmare independently selected from H and substituted or unsubstituted C1-25alkyl, substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, RL, and Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups.According to a preferred embodiment of the present invention, the compound used as collector for selective flotation of lithium minerals is represented by formula (11): wherein R10= -[CH2]- or R10= -[CH-]- ; wherein R28, R29, R30, R31, R32, R33, R34, R36, R37, R36, R37 are independently selected from the group consisting of: OH, NH2, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, preferably Br, Rk, SRk, S(O)Rk S(O)2Rk S(O)ORk S(O)2ORk OS(O)Rk OS(O)2Rk, os(o)or_ner1274_, os(o)_ner1275_Rk OR_NER1277-, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, oc(o)Rk OC(O)Rk OC(O)ORk and OC(O)N(Rk)RL are preferably one or more of R28, R29, R30, R31, R32H more preferably R28, Rk, R30, Rk, R32H ; wherein R35is independently selected from: OH, NH2, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, Rk, SRk, S(O)Rk S(O)2Rk S(O)ORk S(O)2ORk OS(O)Rk OS(O)2Rk OS(O)ORk, os(o)_ner1322_Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, oc(o)Rk OC(O)ORk and OC(O)N(Rk)RL preferably R35ausgewählt is from: H, C1-12hydrocarbon group, acyl group with a C1-12hydrocarbon group, halogen, substituted or unsubstituted C4-12heteroaryl groups, C(O)N(Rk)(RL), particularly preferably R35ausgewählt is from: C(O)N(H)(hexyl), Hexadecyl-4'-pyridinium; wherein Rk, RLand Rmare independently selected from H and substituted or unsubstituted C1-25alkyl, substituted or unsubstituted C1-25alkenyl, substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, RLand Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups.Formula (2) represents compounds having the punicin structure (at least when B is simultaneously a pyridinium or a benzo-annellated pyridinium compound) having at least one OH group, i.e. A is the aromatic group substituted with one or more OH and / or SH groups. The OH group can be deprotonated depending on the pH. When A is represented by formula (2), A is directly bonded / linked to B. Formula (3) represents compounds having an ylide structure (at least when B is simultaneously a pyridinium or a benzo-fused pyridinium compound), i.e. A is the aromatic group bonded to B via a methylene group of formula -[CH2]- or a methylene carbanion group of formula -[CH-]-. In the case where A is represented by formula (3), A is bonded / linked to B via the methylene group or methylene carbanion group. R10represents the methylene group of the formula -[CH2]- or methylene carbanion group of the formula -[CH-]- of claim 1. R10may be -[CH2]- or -[CH-]-, depending on the pH.The term "bond" or "single bond" refers to a chemical bond between two atoms or two portions of the molecule when the atoms joined by the bond are considered to be part of a larger substructure.R1sowie R2, R2, R4, R5, R6, R7, R8, R9schließen also include the corresponding protonated forms and salt forms with monovalent metal cations of the groups including R1sowie R2, R3, R4, R5, R6, R7, R8, R9darstellen. These protonated forms occur depending on the pH. This pH-dependent behavior in turn enables selectivity in flotation processes. Namely, they are suitable for flotation of various particles having different metals (Li, Cu, Ga, Pt, Pd, etc.). The switchable properties of the punicines / ylides are transferred to the properties of functional groups which are already frequently used in flotation. In this way, the collectors according to the invention for flotation are obtained which can be switched by light and pH. The base is its molecular structure which makes it possible to adjust the electronic properties and thus the interactions (such as σ and n interactions) with ions, surfaces or even organic molecules over a wide range by light and the pH. The properties of the collector can thus be tailored to the respective separation problem by the light scenario in interaction with the pH and / or additives, without the flotation mixture (collector, foaming agent, additives, buffer) having to be changed. Novel collectors are those from the substance class of molecular switches. In preferred embodiments, the properties of collectors and foaming agents may be combined in a single molecule. Thus, the amphiphilic punicin derivatives formed can simultaneously serve as collectors and foaming agents in the case of substitution by long-chain hydrocarbon groups.The term "copperrone" describes an anionic end group -N(O-)-(N=O) with varying cations such as ammonium (NH4+) as counterions or the punicin core itself as a cationic substructure of a zwitterionic species.The term "guanidine" describes an -RkNC(=N)-NRLRm end group or an -RkNC(=N)-NRLlinking group as defined above, wherein Rk, RLand Rmare as defined above.As used herein, the term "alkyl" refers to straight / linear or branched hydrocarbon substituents preferably having from 1 to 20 or 1 to 10 carbon atoms. Examples of alkyl groups are methyl, ethyl, propyl, butyl, isopropyl, sec-butyl, isobutyl and tert-butyl.The term "aryl" refers to and includes both single ring aromatic hydrocarbon groups and polycyclic aromatic ring systems. The polycyclic rings may have two or more rings in which two carbons are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is an aromatic hydrocarbon group, i.e., the other rings may be cycloalkylene, cycloalkenyl, aryl, heterocycles and / or heteroaryls. Preferred aryl groups are those containing six to thirty carbon atoms, preferably six to twenty carbon atoms, more preferably six to twelve carbon atoms. Particularly preferred is an aryl group having six carbons, ten carbons or twelve carbons. Suitable aryl groups include phenyl, biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene, anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene, preferably phenyl, biphenyl, triphenyl, triphenylene, fluorene, and naphthalene. In addition, the aryl group may be optionally substituted.As used herein, the term "heteroalkyl" refers to an alkyl group as described herein in which one or more carbon atoms are replaced by a heteroatom. Suitable heteroatoms include oxygen, sulfur, nitrogen, phosphorus, and the like. Examples of heteroalkyl groups include alkoxy, amino, thioester, poly(ethylene glycol), and alkyl substituted amino.The term "heteroaryl" refers to and includes both single ring aromatic groups and polycyclic aromatic ring systems containing at least one heteroatom. The heteroatoms include O, S, N, P, B, Si and Se. In many cases, O, S or N are the preferred heteroatoms. Hetero-single ring aromatic systems are preferably single rings having 5 or 6 ring atoms and the ring may contain from one to six heteroatoms. The heterocycle ring systems may have two or more rings in which two atoms are common to two adjacent rings (the rings are "fused"), wherein at least one of the rings is a heteroaryl, i.e., the other rings may be cycloalkylene, cycloalkenyl, aryl, heterocycles and / or heteroaryls. The heteropolycyclic aromatic ring systems may have one to six heteroatoms per ring of the polycyclic aromatic ring system. Preferred heteroaryl groups are those containing three to thirty carbon atoms, preferably three to twenty carbon atoms, more preferably three to twelve carbon atoms. Suitable heteroaryl groups include pyridine, pyridazine, pyrimidine, pyrazine, quinoline, isoquinoline and acridine. In addition, the heteroaryl group is optionally substituted.As used herein, the term "halogen" or "halo" refers to fluoro (fluoro), chloro (chloro), bromo (bromo), or iodo (iodo), preferably fluoro, chloro, or bromo.The term "negative charge" in the description of the compounds means that free electrons are present in the molecule, so that a unit of an electric charge is formed.In a particularly preferred embodiment of this invention, the compounds have the following formulae: Further preferred compounds have the following formulae: The present invention also relates to flotation compositions containing the collector of the invention.The term "flotation composition" refers to a product or mixture containing the ingredient(s) useful for the purpose of a flotation process. Such ingredients can be, in particular, (a) collectors, in addition to further flotation additives such as foaming agents, regulating agents, damping agents or buffers, and all other agents / additives suitable for flotation.The flotation composition may contain one or more of the compounds defined in the formulae (1) to (5) as collectors.In a preferred embodiment, the collectors as defined in the formulae (1) to (5) can be present in a concentration range from 0.1 to 10% by weight and / or in a concentration range from 0.001 to 5 mmol / l, for example in a concentration in the range from 0.003 to 0.5 mmol / l.In a preferred embodiment, the flotation composition further comprises a foaming agent.The term "foaming agent" is used for a substance or chemical composition which can be used to promote formation and optionally also to stabilize a foam in flotation. The term "foaming solution" is used to describe solutions containing foaming agents. In addition, the foaming solution may contain further foaming agents. Preferred foaming agents according to this invention are short chain alcohols such as methyl isobutyl carbinol, pine oil, cresylic acid and the like as well as emulsifiers, preferably fatty alcohol polyglycol ethers, in particular oleyl alcohol polyglycol ether. As used herein, the term "emulsifier" refers to surfactants that adhere to the surface of the droplets formed during homogenization and form a protective layer that protects the droplets from aggregation. An exemplary emulsifier would be oleyl alcohol polyglycol ether marketed under the name Emulsogen M.In a preferred embodiment, the flotation composition comprises pine oil in the range of 0.5 to 5 wt.% and the emulsifier in the range of 0.01 to 0.5 wt.%In a preferred embodiment, the flotation composition does not comprise any foaming agents or a foaming solution.In a preferred embodiment, the flotation composition further comprises an acid, preferably an acid mixture, wherein the acid mixture preferably comprises H3BO3 H3PO4and / or AcOH.In a more preferred embodiment, the flotation composition comprises the acid mixture, wherein H3BO3in a concentration range of 0.01 to 0.1 M, H3PO4in a concentration range of 0.01 to 0.1 M and AcOH in a concentration range of 0.01 to 0.1 M are used.In a preferred embodiment, NaOH is used to adjust the pH of the flotation composition at a concentration of 0.01 to 0.5 M.In a preferred embodiment, the flotation composition does not comprise acids or an acid mixture.In a preferred embodiment, the flotation composition contains redox-active additives such as sodium dithionite.In a preferred embodiment, the compound of the invention used as collector for the selective flotation of lithium minerals is used in combination with redox active additives such as sodium dithionite.In a preferred embodiment, the compound of the invention used as collector for the selective flotation of lithium minerals is used in combination with redox active additives such as sodium dithionite, said compound having a viologenic structure.The present invention also relates to a flotation process comprising the steps of: a) providing a suspension of a mixture of at least two kinds of particulate materials in a solvent, preferably water; b) combining the flotation composition as defined in any one of claims 8 to 11 with the suspension of step a); c) conditioning the mixture of step b) for the duration of a conditioning time to form one or more kinds of particulate materials on the surface of which at least a part of the collector enriched in the flotation composition as defined in any one of claims 8 to 11; d) adjusting the mixture of step c) to a temperature; e) introducing a flotation gas for forming a flotation foam at the surface of the solvent, wherein the flotation foam comprises a part of the particulate materials to be separated from the remaining part of the particulate materials, f) separating the flotation foam from the suspension; wherein the particulate materials comprise lithium minerals and gangue materials; wherein the selective flotation of lithium minerals is carried out using a conditioning time CT ≥ 3 min, preferably > 5 min, particularly preferably > 10 min, and / or wherein the selective flotation of lithium minerals is carried out at a temperature ≤ 10° C. or ≥ 25° C., preferably ≤ 5° C. or ≥ 40° C.Step a) refers to the provision of a suspension of a mixture of at least two types of particulate materials in a solvent, preferably water. This step may also include a method of milling the material mixture to obtain a suitable particle size (or treatment with acids or bases or plasma treatment of the mineral or other chemical as well as physical treatments) before the solvent is added.Step b) refers to the combination of the flotation composition described herein with the suspension from step a).Step c) refers to conditioning the mixture of step b) for a conditioning time period to form one or more types of particulate materials on the surface of which at least a portion of the collector comprised by the flotation composition described herein accumulates.During this step, the collector accumulates on the surface of one or more types of particulate materials that have specific surface wettability (usually via the polar portion of the collector, which is typically amphiphilic), forming a hydrophobic layer (derived from the nonpolar portion of the collector) on the surface of the one or more types of particulate materials. Examples of literature describing flotation, including the parameters for controlling accumulation, are:B. A. Wills, T. Napier-Munn, Mineral processing technology, Elsevier, Amsterdam 2006, 267 pp.;R.M.G. Lima, P.R.G. Brandao, A.E.C. Peres, Miner. Eng. 2005, 18, 267-273;X. Klein, G. Mei, T. Zhao, Sep. Purif. Technol. 2013, 103, 187-194.M. Ejtemaei, M. Gharabaghi, M. Irannajad, Adv. Colloid Interface. Sci. 2014, 206, 68-78;S. Aghazadeh, S. K. Mousavinezhad, M. Gharabaghi, Adv. Colloid Interface. Sci. 2015, 225, 203-217;Z. J. Wu, X. M. Wang, H. N. Liu, H. F. Zhang, J. D. Miller, Adv. Colloid Interface. Sci. 2016, 235, 190-200;Y. Xing, M. Xu, X. Gui, Y. Cao, B. Bebel, M. Rudolph, S. Weber, M. Kappl, H.-J. Butt, Adv. Colloid. Interface Sci. 2018, 256, 373-392;T. N. Hunter, R. J. Pugh, G. V. Frans, G. J. Jameson, Adv. Colloid Interface Sci. 2008, 137, 57-81;H. Polat, D. Erdogan, J. Hazard. Mater. 2007, 148, 267-273.R. M. Raman, S. Ata, G. J. Jamerson, Int. J. Miner. Process. 2012, 106, 70-77;D. Zamboulis, S. Ataroudi, A. Zouboulis, K. Matis, Desalination 2004, 162, 159-168.Step d) refers to introducing a flotation gas to form a flotation foam at the surface of the solvent. The flotation foam preferably comprises only one kind of particulate materials or more than one kind of materials, with the exception of one or more remaining kinds of particulate materials, in order to achieve a good separation. It is also possible to achieve separation of the mixture when the flotation mixture comprises more or even all kinds of particulate materials, but in a different weight ratio than in the original mixture. This means that one or more desired materials accumulate in the foam or remaining suspension. A desired separation can be achieved by repeating the flotation. Accordingly, the separated flotation foam has a different composition of the particulate materials or a different mixture of particulate materials.During flotation, a gas (e.g. air or nitrogen) is introduced in the form of gas bubbles with the aid of a pump and a regulating valve (rotameter). The one or more types of particulate materials having a hydrophobic layer after conditioning attach to the gas bubbles rising to the surface of the solvent and form a foam, thus comprising the one or more types of particulate materials having a hydrophobic layer after conditioning.Step e) relates to the separation of the flotation foam from the mixture of at least two types of particulate materials. In this way, for example, the minerals comprised in the flotation foam can be separated from the gangue materials remaining in the mixture of at least two types of particulate materials. This can be achieved, for example, by skimming the flotation foam. Step e) provides two separate particulate materials or mixtures of particulate materials (in the form of suspensions) which can be subjected to known processing processes. The resulting materials, while still being mixtures of different types of particulate solids, may be re-flotation, for example flotation under other conditions, to again separate one or more types of materials from these mixtures.The flotation process can be carried out, for example, in a Hallmond tube. In the Hallmond tube, the flotate (goes with the foam to the top of the Hallmond tube) is separated from the residues (remains in suspension). The two are filtered off separately from one another. The residues are rinsed several times with water from the Hallimond tube and each combined amount of residue is dried and weighed.The flotation process can be carried out on a small scale typically in Hallimond tubes, for example with a volume of 250 ml and a medium pore frit glass through which the air can flow into the apparatus. The air flows can be set to 1 cm3 / min to 350 cm3 / min, preferably to 32 cm3 / min to 170 cm3 / min. For continuous stirring, a stirring bar is placed in the Halimond tube on the frit glass and the speed of the external magnetic stirrer is set to 500 U / min.The term "suspension" refers to a heterogeneous mixture of a solid, typically in the form of particles dispersed in a liquid. In a suspension, the solid particles are in the form of a discontinuous phase dispersed in a continuous liquid phase.As used herein, the term "conditioning" refers to a step or phase in a flotation process wherein no gas is introduced for foaming. During conditioning, it is believed that the collector adheres to the surface of a particular particulate material having a specific surface wettability (typically via the polar portion of the collector, which is typically amphiphilic) to form a hydrophobic layer (derived from the nonpolar portion of the collector) on the surface of the particular particulate material.The term "flotation gas" may refer to any gaseous substance suitable for flotation. Although air is often used as the flotation gas in practice, other types of gaseous materials may also be used, as are known to those skilled in the art.In a preferred embodiment, the conditioning time is in the range of 1 to 24 hours.In one embodiment, the conditioning time CTis 5 minutes or more.In one embodiment, the conditioning time CTis 10 minutes or more.In one embodiment, the conditioning time CTis 60 minutes or more.In one embodiment, the conditioning time CTis 120 minutes or more.In one embodiment, the selective flotation of lithium minerals is carried out at a temperature of 1° C. or ≥40 ° C., preferably at a temperature of 1° C. or ≥50 ° C.In one embodiment, the flotation process is carried out at a pH>7, preferably at a pH below 10.In a preferred embodiment, the particulate materials comprise lithium minerals and gangue materials; wherein the lithium minerals are selected from the group consisting of lithium aluminate, spodumene, chalcopyrite, monazite, galaxite, lithium carbonate, lithium oxide, and combinations thereof; wherein the gangue materials are silicate minerals, preferably selected from the group consisting of gehlenite, pyrite, zinc blende, galenite, and combinations thereof.In a preferred embodiment, step c), step d) and step e) further comprisei) performing an exposure or a exclusion of light to switch the collector; and / orii) increasing or decreasing the pH of the suspension to switch the collector.It is possible to carry out steps c), d) and e) of the method according to this embodiment in order to flo at least one type of particulate materials from the suspension of a mixture of at least two types of particulate materials in a first cycle. Thereafter, steps c), d) and e) may be repeated in a second cycle to treat the remaining suspension of a mixture of at least two types of particulate materials from the first cycle. In this second cycle, a different light irradiation / exclusion and / or pH (as compared to the setting used in the first cycle) may be used to adjust the compound of this invention used as collector so that different types of particulate materials are selectively floated.In this way, it is theoretically possible to separate complex mixtures of particulate materials. According to the invention, by carrying out the process steps c), d) and e), the relative proportions of the kinds of particulate materials in the solvent are changed, enabling the selective separation. Upon repeating process steps c), d) and e), either another type of compound of this invention may be added to separate another type of particulate materials, or the same compound may be added while selective separation is achieved using different process conditions, e.g., with / without light.In the method according to the invention, for example, the mixture from step c) contained in a reaction vessel could be irradiated from the outside with the aid of a specific light source. Suitable for this purpose are, for example, LED lamps or lasers of certain wavelengths. The reaction vessel may also be provided with a specific light filter in order to exclude specific wavelength ranges of the light. Similar reaction vessels could also allow complete exclusion of light if desired.Specific pH buffer solutions, particularly universal buffer solutions having a broad pH range such as the McIlvaine buffer, are suitable for adjusting the pH of the mixture of step c), step d) and step e). This would allow, for example, the pH to be readjusted during the process by adding small amounts of strong acids or bases. For example, if a first particulate material was already adsorbed by the collector of the invention under certain conditions, a change in pH by adding acid or base could allow adsorption of a second particulate material comprised by the solution, at the same time as a third particulate material could remain in the suspension, while the collector that floats the first and second particulate materials would have to be separated from the solution.In another preferred embodiment, step c), step d) and step e) further comprise carrying out light irradiation, wherein the illuminance is > 5000 lux, preferably > 10000 lux, particularly preferably > 50000 lux and the wavelength of the irradiated light is in the range from 10 nm to 1400 nm, preferably in the range from 200 nm to 700 nm, particularly preferably in the range from 200 nm to 700 nm.In another preferred embodiment, step c), step d) and step e) further comprise carrying out exclusion of light, wherein the illumination intensity is <500 lux, preferably <100 lux, particularly preferably <40 lux.In another preferred embodiment, step c), step d) and step e) further comprise increasing or decreasing the pH, preferably to a pH within a pH range of pH=1 to pH=12, particularly preferably to a pH within a pH range of pH=2 to pH=11. It is possible to set a pH in the flotation composition before the start of flotation and to change the pH during the process.In a preferred embodiment, in step c), step d) and step e) the light irradiation or the exclusion of light and / or the pH value is adjusted depending on the minerals and / or gangue materials.The performance of the flotation process according to the invention under irradiation / exclusion of light and / or at a specific pH value enables selective flotation of minerals, exploiting the switchable nature of the compounds according to the invention.For example, in the case of lithium aluminate, a pH of 2 (in combination with laser irradiation having a wavelength of 390-400 nm) and a pH of 10-11 (in combination with daylight and darkness < 40 lux) were chosen. In the case of spodumene, pH values of 2 (in combination with daylight) and 8 (in combination with laser irradiation with a wavelength of 390-400 nm) were chosen. In the case of galaxite, pH values of 2 (in combination with daylight) and pH values of 5 and 10 were chosen. In the case of gehlenite, flotation was suppressed at pH 2 under irradiation with a halogen element / halogen lamp.The invention also relates to the following numbered embodiments:1. Use of a compound as collector for selective flotation of minerals, characterized in that the compound is represented by formula (1): wherein Aa) is an aromatic group substituted by one or more OH and / or SH groups, orb) is an aromatic group attached to B via a methylene group of formula -[CH2]- or a methylene carbanion group of formula -[CH-]-; wherein Bi) is a pyridinium or benzo-fused pyridinium compound, wherein A is attached to the nitrogen atom of the pyridinium or benzo-fused pyridinium compound, orii) is a substituted or unsubstituted pyridyl or benzo-fused pyridyl group.2. The use of Embodiment 1, wherein A is represented by formula (2) or (3): ; wherein the dashed line represents the bond to B; wherein R1ausgewählt is from: H, OH, SH, NH2, S(O)2OH OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(RL)Rk SC(O)N(RL)Rk, sc(s)n(RL)Rk NH-OH, copperrone and guanidine, wherein Rkand RLare independently selected from H and substituted or unsubstituted C1-25alkyl, substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rkand RLoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups; wherein R2, R3, R4, R5, R6, Rk, RL, Rkare independently selected from the group consisting of: H, OH, NH2, SH, CF3, CN, c(o)nh_ner1446_, c(o)h, c(o)oh, halogen, Rk, SRk, S(O)Rk, S(O)2Rk, S(O)ORk, S(O)2ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, OR3, n(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, OC(O)Rk, OC(O)ORk, oc(o)n(Rk)RL wherein Rk, R6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, are independently selected from H and substituted or unsubstituted Ck, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, RLand Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups; wherein R10= -[CH2]- or R10= -[CH-]-. 3. the use of embodiment 1 or 2, wherein B is represented by formula (4) or (5): ; wherein the dashed line represents the bond to A; wherein R11, R12, R13, R2, R15, R16, R17, R18, R19 are independently selected from: H, OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, c(o)oh, halogen, Rk, SRk, S(O)Rk, S(O)2Rk, S(O)ORk, S(O)2ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORk, N(Rk)(RL ), p(o)(or_ner1526_)(or_ner1527_), op(o)(or_ner1528_)(or_ner1529_), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, OC(O)Rk, OC(O)ORk, OC(O)N(Rk)RL, wherein at least one of R11, R12, R13, R14 and R15 and at least one of R16, R17, R18 and R19 is not H, preferably at least one of R11, R12, R13, R14 and R15 and at least one of R16, R17, R18and R19Rkist wherein R1-25alkyl, substituted or unsubstituted C1-25alkenyl, substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl, or substituted or unsubstituted C4-12heteroaryl groups, wherein R18and wherein R1-25alkyl, substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl, or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, Rkand Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups. 4. the use according to embodiment 2 or 3, wherein in formula (2), at least one of R1, R2, R3, and R4weder H is still OH; preferably wherein in formula (2), additionally one or two of R1, R2, Rk, and R4OH are. 5. flotation composition comprising the collector defined in any one of Embodiments 1 to 4. 6.The flotation composition according to embodiment 5, wherein the collector as defined in any of embodiments 1 to 4 is present in a concentration range of 0.1 to 10 wt.% and / or in a concentration range of 0.001 to 5 mmol / L, such as in a concentration range of 0.003 to 0.5 mmol / L. 7.The flotation composition according to embodiment 5 or 6, further comprising a foaming agent. 8. the flotation composition of Embodiments 5 to 7, further comprising an acid, preferably a mixture of acids; preferably wherein the acid mixture comprises H3BO3 H3PO4, and / or AcOH.9. A flotation process comprising the steps of: a) providing a suspension of a mixture of at least two types of particulate materials in a solvent, preferably water; b) combining the flotation composition as defined in any of embodiments 5 to 8 with the suspension of step a) c) conditioning the mixture of step b) for a conditioning time to form one or more types of particulate materials on the surface of which at least a portion of the collector which is enriched by the flotation composition as defined in any of embodiments 5 to 8; d) introducing a flotation gas to form a flotation foam at the surface of the solvent, the flotation foam comprising a portion of the particulate materials to be separated from the remaining portion of the particulate materials,e) separating the flotation foam from the suspension.10. The flotation method of Embodiment 9, wherein the particulate materials comprise minerals and gangue materials; wherein the minerals are selected from the group consisting of minerals containing lithium, copper, cobalt, manganese, gallium, niobium, tantalum, platinum group element, and rare earth metal, preferably lithium aluminate, spodumene, chalcopyrite, monazite, galaxite, lithium carbonate, lithium oxide, and combinations thereof; wherein the gangue materials are silicate minerals, preferably selected from the group consisting of gehlenite, pyrite, zinc blende, galenite, and combinations thereof.11. The flotation process according to Embodiment 9 or 10, wherein step c), step d) and step e) further comprisei) performing an exposure or a exclusion of light to switch the collector; and / orii) increasing or decreasing the pH of the suspension to switch the collector.12. The flotation method according to embodiment 11, wherein the exposure or exclusion of light and / or the pH is adjusted depending on the minerals and / or gangue materials.13. A compound represented by formula (6): wherein D is selected from the group consisting of formulae (7) and (8) ; wherein the dotted line represents the bond to E; wherein R20ausgewählt is selected from: SH, NH2, S(O)2OH OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(RL)Rk SC(O)N(RL)Rk, sc(s)n(RL)Rk NH-OH, copperrone and guanidine, wherein R_NER1597 and R_NER1598 are independently selected from H and substituted or unsubstituted C_NER1599 alkyl, substituted or unsubstituted C_NER1599 heteroalkyl, substituted or unsubstituted C_NER1601 aryl or substituted or unsubstituted C_NER1602 heteroaryl groups, wherein two or more of Rkand RLoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups; wherein R27ausgewählt is from: OH, NH2, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, SRk, S(O)Rk S(O)2Rk S(O)ORk, s(o)_ner1616_or_ner1617_, os(o)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, c(o)Rk, C(O)ORk, C(O)N(RL)Rk OC(O)Rk, OC(O)Rk, OC(O)ORk and OC(O)N(Rk)RL where Rk, RLand Rmare independently selected from H and substituted or unsubstituted C1-25alkyl groups, A substituted or unsubstituted C1-25heteroalkyl, substituted or unsubstituted C6-14aryl, or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, RL, and Rmoptional together form one or more substituted or unsubstituted C6-14aryl, or substituted or unsubstituted C4-12heteroaryl groups; wherein R21, R22, R23, R24, R25, R26, Rk, independently of one another, are selected from: H, OH, NH2, SH, CF3, CN, C(O)NH2 C(O)H, C(O)OH, halogen, Rk, SRk, S(O)Rk S(O)2Rk S(O)ORk S(O)2ORk OS(O)Rk OS(O)2Rk, os(o)or_ner1676_, os(o)_ner1677_Rk ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, C(O)N(RL)Rk, oc(o)Rk, OC(O)Rk OC(O)ORk and OC(O)N(Rk)RL where Rk, RL and Rm are independently selected from H and substituted or unsubstituted C1-25 alkyl, substituted or unsubstituted C1-25 heteroalkyl, substituted or unsubstituted C6-14 aryl or substituted or unsubstituted C4-12 heteroaryl groups, wherein two or more of Rk, RL, and Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups; wherein R29= -[CH2]- or R29= -[CH-]-; wherein Ei) is a pyridinium or benzo-fused pyridinium compound, wherein D is attached to the nitrogen atom of the pyridinium or benzo-fused pyridinium compound, orii) is a substituted or unsubstituted pyridyl or benzo-fused pyridyl group.14. The compound according to Embodiment 13, wherein E is represented by Formula (9) or (10): ; wherein the dashed line represents the bond to D; wherein R30, R31, R32, R33, R34, R35, R36, R37, R38 are independently selected from: H, OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, Halogen, Rk, SRk, S(O)Rk, S(O)2Rk, S(O)ORk S(O)2ORk, OS(O)Rk, OS(O)2Rk, OS(O)ORk, OS(O)2Rk, ORk, N(Rk)(RL), P(O)(ORk)(ORL ), op(o)(or_ner1746_)(or_ner1747_), SiRkRLRm, C(O)Rk C(O)ORk, C(O)N(RL)Rk, OC(O)Rk, OC(O)Rk, OC(O)ORk, OC(O)N(Rk)RL wherein Rk, RLand Rmindependently of one another are selected from H and substituted or unsubstituted C1-25alkyl, substituted or unsubstituted Ckheteroalkyl, substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups, wherein two or more of Rk, RLand Rmoptional together form one or more substituted or unsubstituted C6-14aryl or substituted or unsubstituted C4-12heteroaryl groups.DESCRIPTION OF THE FIGURESFIG. 1: FIG. 1 shows the switchable properties of punicin as a function of the ambient conditions. Figure 2: Figure 2 shows an exemplary toolbox for the synthesis of compounds used as collectors for flotation according to the present invention. FIG. 3: FIG. 3 shows the relationship of ylidene of the hetearenium carbanion type with punicins. Figure 4: Figure 4 shows the molecular mechanisms causing the switchable properties of ylidene. Figure 5:5 shows the experimental setup for carrying out the flotation (or microflotation) experiments as carried out in the context of this invention using Halimond tubes. The reference numerals represent the following elements: 1 stirrer rod, 2 pore filter glass, 3 air stream, 4 magnetic stirrer, 5 non-floated fraction, 6 flotation product. FIG. 6 : a) Schematic illustration of the punicin derivatives used. b) Illustration of the results (recovery rates / yields) of the flotation tests with various punicin derivatives. FIG. 7 : Flotation of LiAlO2bei different temperatures using 60 μL collectors (4-tert-butylpunicin; 8.58 μmol / L) and 30 μL foaming agents (α-pinene). Flotation was carried out for 3 minutes at an air flow rate of 32 ml / min, a stirring speed of 500 U / min and a pH of 11. FIG. 8 : Flotation of LiAlO2bei different conditioning times. FIG. 9 : Flotation yields at different molar ratios of dithionite / collector. Volume of the collector=60 μL. The 95% confidence interval is indicated. FIG. 10 : Flotation yields at different molar ratios of dithionite / collector. Volume of the collector=200 μL. The 95% confidence interval is indicated.Examples1. Synthesis of Punicin Derivatives1.1 Punicin: Synthesis of its fully protonated form, N-(2',5'-dihydroxyphenyl)pyridinium chloride, and its conversion to the mesomeric punicinbetaines, 4-hydroxyphenyl-2-pyridinio-1-olate / 4-hydroxyphenyl-3-pyridinio-1-olate (two tautomers)1,4-Benzoquinone (2.7 g, 25 mmol) was suspended in 8 ml of glacial acetic acid and pyridine (2 ml, 25 mmol) was added. After diluting the resulting dark precipitate with 4 ml of water, 8 ml of 18% hydrochloric acid were added with heating. After cooling, the yellow solid was filtered off, washed with water, recrystallized from water and dried in vacuoto give yellow punicin needles in protonated form as chloride, melting point 193° C. (monohydrate), yield 4.0 g (16.3 mmol; 65%). IR (KBr): 3119, 1618, 1512, 1465 cm-1; uv (MeOH): Imax: 310 nm;1H NMR (400 MHz, DMSO-d6): d=6.99 (dd, ==8.9 / 2.9 Hz, 1H), 7.08 (d, J=2.9 Hz, 1H), 7.16 (d, J=8.9 Hz, 1H), 8.25-8.28 (m, 2H), 8.75 (tt, J=7.8 / 1.4 Hz, 1H), 9.15-9.17 (m, 2H), 9.83 (s, 1H), 10.54 (s, 1H) ppm. EIMS: m / z=186 (M+ 100); Anal. calcd for C11H12ClNO3· H2O (241.05), C: 54.67; H: 5.00; Cl: 14.67; N: 5.80; O: 19.86. Found: C: 54.65; H: 5.02; Cl: 14.33; N: 5.62; O: 20.38.The protonated punicin described above (500 mg) was dissolved in 40 ml of a water-ethanol mixture (3:1) and treated with Amberlite IRA-402 in its hydroxy form (20 ml, pH 7.5). The eluate was evaporated to dryness to give a brown solid of the mesomeric betaines in a yield of 78 %, melting point 115°C.IR (KBr): 3119, 3065, 1628, 1470, 1443 cm_1; UV (MeOH): Imax350 nm; LH-NMR (DMSO-d6): 9.11 (m, 2H; a-H), 8.60 (t, J = 7.4 Hz, 1H; g-H), 8.17 (t, J = 7.4 Hz, 2H; b-H), 6.89 (s, 1H; 6-H), 6.80 (s, 2H; 3-h, 4-h) ppm; OH undetectable; 13C NMR (200 MHz, DMSO-d_NER1787)=148.8(C-2), 145.9(g-C), 139.9(2C; a-C), 130.3(2C; C-4, C-6), 127.3(2C; b-C), 119.7(C-5), 111.7(2C; C-1, C-3) ppm; ESIMS m / z=186(M+ 100).1.2 N-(2',5'-dihydroxyphenyl)-4-methylpyridinium chloride2,7 g (25.0 mmol) of p-benzoquinone were suspended in 8 ml of concentrated acetic acid and 2 ml (25.0 mmol) of 4-methylpyridine were added slowly. The resulting dark mixtures were diluted with 4 ml of water, heated and treated with 8 ml of 18% hydrochloric acid. On cooling, a solid precipitated out which was filtered off, recrystallized from water and dried in vacuo. Yield: 4.25 g (18.0 mmol; 72%) of a yellow solid, melting point 258° C.IR: 3394, 3173, 1637, 1519, 1459, 1400, 1350, 1329, 1280, 1216, 827, 792 cm-1. UV (MeOH): λmax=250, 315, 385 nm.1H-NMR: δ 10.29 (s, 1H), 9.64 (s, 1H), 8.99 (d, J=6.7 Hz, 2H), 8.08 (d, J=6.7 Hz, 2H), 7.00 (m, 3H), 2.70 (s, 3H) ppm.13C NMR: δ160.2, 150.2, 145.2, 142.6, 128.0, 119.0, 118.0, 112.6, 21.6 ppm. EIMS: m / z = 201 (M+, 75), 110 (100), 93 (60). Anal. calculated for C12H14ClNO3(255,07 )· H2O: C: 56.37; H: 5.52; Cl: 13.87; N: 5.48; O: 18.77. Found: C: 56.09; H: 5.46; Cl: 13.83; N: 5.11; O: 19.51.1.3 1-(2',5'-Dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chlorideThe reaction was carried out under nitrogen. 1-(2',5'-Dihydroxyphenyl)-4-methylpyridinium chloride (1.0 g, 4.2 mmol) was dissolved in 40 ml of anhydrous methanol. A sample of 0.5 ml (4.6 mmol) of valeraldehyde and 0.1 ml of piperidine was added. The reaction mixture was stirred under reflux temperature for fifteen hours. Column chromatography using chloroform:methanol = 8:1 as the eluant gave the crude product which was dried in vacuo. The reaction gave 0.24 g (18%) of an orange solid; decomposition at 278°C (DSC).1H NMR (600 MHz, DMSO-d6): δ = 10.42 (bs, 1H), 9.73 (bs, 1H), 8.97 (d, JH-H= 6.9 Hz, 2H), 8.20 (d, JH-H= 6.9 Hz, 2H), 7.34 - 7.2 9 (m, 1H), 7.12 (d, J_NER #1_=8.9 Hz, 1H), 7.03 (d, JH-H=2.8 Hz, 1H), 6.96 (dd, 1H, JH-H=8.9, 2.8 Hz, 1 H), 6.80 (d, JH-H=15.1 Hz, 1 H), 2.37 (q, JH-H=7.3 Hz, 2 H), 1.50 (quint, JH-H=7.3 Hz, 2 H), 1.37 (sext, JH-H=7.3 Hz, 2 H), 0.92 (t, JH-H=7.3 Hz, 3 H) ppm.13C-NMR (150 MHz, DMSO-d_NER189): δ=153.5, 150.3, 147.5, 145.8, 142.7, 129.6, 125.8, 123.2, 119.0, 118.0, 112.6, 32.7, 29.9, 21.7, 13.7 ppm. IR (ATR): v=225, 1621, 1504, 1446, 1342, 1269, 1194, 1119, 975, 852, 824, 791, 480 cmL. HR-ESI-MS: calculated for [C17H20NO2]+: 270.1489. Found: 270.1494.1.4 1-(2',5'-Dihydroxyphenyl)-4-ethylpyridinium chlorideTo a suspension of p-benzoquinone (2.2 g, 20 mmol) in 20 mL of concentrated glacial acetic acid was added 4-ethylpyridine (2.3 mL, 20 mmol). The mixture was stirred at room temperature for 3 days and then treated with an excess of concentrated hydrochloric acid. The resulting solid was filtered and washed alternately with chloroform and ethyl acetate. Recrystallization from water afforded 1.7 g (34%) of a yellow solid; slow decomposition >190 °C.1H NMR (400 MHz, DMSO-d6): δ=10.38 (bs, 1H), 9.70 (bs, 1H), 9.03-9.01 (m, 2H), 8.12-8.11 (m, 2H), 7.10 (d, JH-H=8.9 Hz, 1H), 7.03 (d, JH-H=2.9 Hz, 1H), 6.96 (dd, JH-H=8.9, 2.9 Hz, 1H), 3.01 (q, m, p, JH-H=7.6 Hz, 1 H), 1.32 (t, JH-H=7.6 Hz, 1 H) ppm.kC-NMR (100 MHz, DMSO-d6): δ=165,0, 150.3, 145.6, 142.7, 129.7, 126.9, 119.1, 118.0, 112, 6, 28.2, 13.4 ppm; IR (ATR): v=397, 3330, 3208, 3038, 1631, 1507, 1457, 1380, 1341, 12, 82, 1203, 1179, 1131, 849, 822, 787, 716, 692, 662, 628, 585, 549, 477, 464 cm-1. HR-ESI-MS: calculated for [C13H14NO2]+: 216.1019. Found: 216.1034.1.5 1-(2',6'-dibromo-3',4',5'-trihydroxyphenyl)-4-methylpyridinium chlorideWith vigorous stirring, bromine (2.326 mL, 45.4 mmol) was added slowly to a solution of pyrogallol (5.7 g, 45.4 mmol) and 4-methylpyridine (8.855 mL, 91 mmol) in methanol (25 mL). The temperature was maintained between 0°C and 6°C and the mixture was stirred overnight at room temperature. Then, 10 ml of concentrated HCl was added. After several days, crystals precipitated which were filtered off and washed with methanol, yield: 5 g (30%), melting point: 185 °C.1H NMR (600 MHz, DMSO-d6) d=10.31 (s, 3H), 9.12 (d, J=6.6 Hz, 2H), 8.28 (d, J=6.7 Hz, 2H), 2.76 (s, 3H) ppm.13C NMR (150 MHz, DMSO-d6) d=163.3, 146.5, 144.4, 137.6, 132.0, 134.0, 129.6, 99.7 ppm. IR (ATR): 3450, 1364, 1000, 782, 651, 520, 470, 436 cm-1.1.6 4-(tert-Butyl)-1-(2',5'-dihydroxyphenyl)pyridinium chlorideA sample of 1,4-benzoquinone (2.7 g, 25 mmol) was suspended in 8 ml of glacial acetic acid and 4-tert-butylpyridine (2 g, 25 mmol) was added. After diluting the resulting dark precipitate with 4 ml of water, 8 ml of hydrochloric acid was added with heating (100°C, 35 min). After cooling, the brown precipitate was filtered off, washed with water, recrystallized from water and dried in vacuo, yield 4.3 g (70%), melting point: 160 °C.1H NMR (600 MHz, DMSO-d6): δ=1.43 (s, 9H), 6.96 (dd, J1=3.53 Hz, J2=5.88 Hz, 1H), 7.04 (d, J=2.59 Hz, 1H), 7.12 (d, J=8.93 Hz, 1H), 8.25 (d, J=6.2 Hz, 2H), 9.04 (d, J=7.06 Hz, 2H), 9.76 (s, 1H), 10.44 (s, 1H).13C NMR (150 MHz, DMSO-d6): δ=29,4, 36.5, 112.6, 118.1, 119.8, 124.6, 129.9, 142.6, 147.8, 149.5). IR (ATR): 3365, 3036, 2988, 2685, 2113, 1948, 1729, 1631, 150, 0, 1369, 1270, 1200, 1111, 1000, 830, 800, 684, 473 cm-1.1.7 4-(2',5'-dihydroxyphenyl)pyridineIn a Schlenk flask, 2-bromo-1,4-dimethoxybenzene (4.0 mmol), pyridin-4-ylboronic acid (590.0 mg, 1.2 equivalents, 4.8 mmol), and potassium carbonate (1.658 g, 3 eq, 12.00 mmol) were suspended with 12 mL of 1,4-dioxane and 4 mL of H2O under N_NER1842 atmosphere. To degas the mixture, it is placed in an ultrasonic bath for 10 minutes while blowing nitrogen into the flask. Finally, Tetrakis(triphenylphosphin)palladium (0) (462.7 mg, 0.1 equivalent, 0.4 mmol) is added to the reaction mixture. The mixture is then stirred under reflux conditions for 48 hours. The crude product is filtered through celite to remove colloidal Pd. The filtrate is then extracted with dichloromethane, the organic phase is separated off and filtered over MgSO4getrocknet. The solvent is removed under reduced pressure, then the product is purified by column chromatography using ethyl acetate as the eluant. A sample of 0.500 g of the resulting 4-(2',5'-dimethoxyphenyl)pyridine (2.3 mmol) was dissolved in 10 ml of anhydrous dichloromethane under an atmosphere of N_NER1844 and cooled to 0°C. 2.33 g BBr3(4 eq, 9.2 mmol, 1 M in DCM, 9.20 mL) was then added dropwise with vigorous stirring. After stirring for 1 hour, the mixture is poured into 50 ml of water. The resulting yellow precipitate is filtered off and washed with water and aqueous KHCO_NER1846 solution. It is then dried under reduced pressure to give 0.401 g (94%) of a yellow solid entstehen.1H NMR (400 MHz, DMSO-d6) δ: 9.26 (br s, 1H, OH), 8.97 (br s, 1H, OH), 8.60 (d, 2H, 9 / 10-H), 7.66 (d, 2H, 8 / 11-H), 6.70-6.83 (m, 3H, 1 / 2 / 4-H) ppm.13C-NMR (100 MHz, DMSO-d6): 150.3, 147.8, 147.4, 124.3, 124.1, 117.3, 117.2, 115.8 ppm.1.8 4-(decyl)-1-(2',5'-dihydroxyphenyl)pyridinium chlorideTo a sample of 0.49 g (4.56 mmol) of p-benzoquinone in acetic acid was added 1.00 g (4.56 ml) of 4-decylpyridine dropwise with constant stirring. After 12 hours, water and concentrated hydrochloric acid were added and the mixture was stirred for an additional 2 hours. More water was then added until a precipitate formed which was filtered off and washed with dichloromethane. Yield 0.88 g (53%), golden solid, melting point: 138.5° C. (Zersetzung).1H NMR (600 MHz, DMSO-d6) δ=10.46 (s, 1H, OH), 9.77 (s, 1H, OH), 9.00 (d, J=6.8 Hz, 2H), 8.11 (d, J=6.8 Hz, 2H), 7.13 (d, J=8.8 Hz, 1H), 7.01 (d, J=2.9 Hz, 1H), 7.04 (dd, J=8.8, 2.9 Hz, 1H), 2.96 (t, J=7.6 Hz, 2H), 1.71 (quint., J = 7.6 Hz, 2H), 1.33-1.21 (m, 14H), 0.85 (t, 3H) ppm.13C-NMR (150 MHz, DMSO-d6) δ = 163.3, 150.1, 145.2, 142.4, 129.4, 127.0, 118.8, 1 77.7, 112.3, 34.64, 31.0, 28.4, 28.4, 28.5, 28.6, 28.7, 28.9, 21.8, 13.7 ppm. IR (ATR): ṽ=367, 3111, 3042, 2914, 2848, 2692, 1641, 1509, 1454, 1335, 1272, 1201, 1123, 907, 855, 817, 795, 720, 693, 630, 614, 556, 536, 469, 410 cm-1. HR-ESI-MS: [C21H30NO2]+berechnet: 328.2271 found: 328.2260.2. Synthesis of Yilde2.1 General Procedure for the Synthesis of IsonicotinamidesTo a solution of 123 mg isonicotinic acid (1.00 mmol) and one equivalent of amine in 2 ml of acetonitrile is added 2 equivalents of 2',2',2'-trifluoroethyl boric acid ester (SHEPPARD's reagent). The mixture is stored in a sealed tube at 100°C for 18 hours. The reaction mixture is cooled to room temperature. The solvent is removed under vacuum. The resulting solid is dissolved in about 50 ml of dichloromethane and extracted three times with about 20 ml of saturated NaHCO_NER1860 solution. The organic phase is washed three times with about 20 ml of water and dried over magnesium sulfate. The solvent is removed under vacuum and the resulting product is dried under vacuum. If necessary, the amide is washed amine-free with diethyl ether. _NER1861The method is well suited for the synthesis of various isonicotinamides. The spectroscopic data of n-hexylisonicotinamide are listed by way of example. _NER1862Yield: 110 mg (0.53 mmol, 53%), colorless powder... NER1863..RTM. H NMR (400 MHz, CDCl3 ): δ=8.73 (d,3JH,H= 3.9 Hz, 2H, H-2.2), 7.69 (d,3JH,H= 4.4 Hz, 2H, H-3.3'), 6.49 (br, 1H, H-6), 3.43-3.48 (m, 2H, CH2), 1.58-1.66 (m, 2H, CH2), 1.29-1.39 (m, 6H, ch_ner 1871_), 0.88 (t,3JH,H= 7.1 Hz, 3H, H-12) ppm.13C-NMR (100 MHz, CDCl3): δ= 165.0 (o, 1C, C-5), 149.4 (+, 2C, C-2, 2'), 143.0 (o, 1C, C-4), 121.4 (+, 2C, C-3, 3'), 40.3 (-, 1C, CH2), 31.4 (-, 1C, CH2), 29.4 (-, 1C, CH2), 26.6 (-, 1c, ch_ner1879_), 22.5 (-, 1c, ch_ner1880_), 14.0 (+, 1c, C-12) ppm.2.2 General Procedure for the Synthesis of Benzylpyridinium-4-carboxamidesTo a solution of 5 mmol isonicotinamide in 10 ml acetonitrile is added 1.1 equivalents of benzyl bromide. The mixture is stored in a sealed tube at 100°C for 18 hours. The solvent is removed under vacuum. The crude product is mixed with about 30 ml of dichloromethane and stirred for 10 minutes. The suspension is filtered through a glass filter _NER1881The process is well suited for the synthesis of various benzylpyridinium-4-carboxamides. The spectroscopic data of benzylpyridinium-4-n-hexyl carboxamide are exemplified. _NER1882Yield: 270 mg (0.71 mmol, 64%), colorless powder... NER1883..RTM. H NMR (600 MHz, DMSO-d..NER1884... ):.delta.=9.37 (d,3JH,H= 6.8 Hz, 2H, H-2.2'), 9.23 (t,3JH,H= 5.5 Hz, 1H, H-12), 8.45 (d,3JH,H= 6.8 Hz, 2H, H-3.3'), 7.57 (dd,3JH,H= 7.7 Hz,4JH,H= 1.5 Hz, 2H, H-7.7'), 7.43-7.49 (m, 3H, H-8.8', H9), 5.93 (s, 2H, H-5), 3.32 (dt,3JH,H= 5.5 Hz,3JH,H= 7.0 Hz 2H, H-13), 1.54 (qui,3JH,H= 7.1 Hz, 2H, H-14), 1.25-1.35 (m, 6H, H-15 / 16 / 17), 0.87 (t,3JH,H= 7.1 Hz, 3H, H-18) ppm.13C-NMR (150 MHz, DMSO-d6): δ = 162.1 (o, 1C, C10), 149.2 (o, 1C, C4), 146.1 (+, 2C, C2,2'), 134.5 (o, 1C, C6), 129.9 (+, 1C, C9), 129.7 (+.2C, C8,8'), 129.3 (+, 2C, C7,7'), 126.6 (+, 2C, C3,3'), 63.8 (-, 1C, C-5), 40.1 (-, 1C, C13), 31.3 (-, 1C, G15 / 16 / 17), 29.0 (-, 1C, C-14), 26.5 (-, 1C, G15 / 16 / 17), 22.4 (-, 1C, G15 / 16 / 17), 14.3 (+, 1C, G18) ppm.2.3 Process for the synthesis of 4,4'-benzylalkylbipyridinium dibromides.A sample of 3 mmol of 1-benzyl-4,4'-bipyridinium bromide and 3 equivalents of alkyl bromide is dissolved in 15 ml of DMF and maintained at 85°C for 18 hours. The mixture is filtered hot through a preheated glass filter. The yellow product is washed with diethyl ether and dried under vacuum. _NER1905The process is well suited for the synthesis of various disubstituted bipyridinium salts. The spectroscopic data of benzyl hexadecyl bipyridinium dibromide are exemplified.MO-M-0551H-NMR (400 MHz, methanol-d4): δ = 9.25 (d,3JH,H= 5.9 Hz, 2H), 9.19 (d,3JH,H= 6.4 Hz, 2H), 8.59 (t,3JH,H= 7.4 Hz, 4H), 7.49-7.52 (m, 2H), 7.37-7.41 (m, 3H), 5.90 (s, 2H), 4.65 (t,3JH,H= 7.1 Hz, 2H), 1.99 (qui,3JH,H= 7.1 Hz, 2H), 1.14-1.37 (m, 26H), 0.79 (t,3JH,H= 6.5 Hz, 3H) ppm._NERmn1_C-NMR (100 MHz, methanol-d_NERmn2_): δ=150.3, 149.7, 145.6, 132.9, 129.8, 129.4, 129.0, 127.2, 127.0, 122.3, 64.4, 61.9, 31.6, 31.2, 29.3-29.4, 29.2, 29.1, 29.0, 28.7 ppm.3. Flotation Tests with Punicin DerivativesThe flotation tests were carried out in a 250 ml Hammond tube (see FIG. 5 ) having a medium-pore frit glass through which the air could flow into the apparatus.The light sources for all experiments were turned on at the beginning of irradiation with a laser lamp (390-400 nm) or a halogen lamp (R7s lamp). In the first step, the mineral was suspended and stirred with a stirring bar in distilled water or buffer at 500 U / min. After one minute (= conditioners time), the collector was added and after another minute of conditioning, the foaming agent was added. After another minute of conditioning, the remaining volume was made up to 250 ml and the pump turned on to adjust the air flow (32 cm3 / min or 170 cm3 / min). Thereafter, flotation was carried out for 3 or 10 minutes. The flotate and the residue were then filtered off separately from one another.The buffer consisted of 0.04 M boric acid, 0.04 M phosphoric acid and 0.04 M acetic acid and the required pH was adjusted by addition of 0.1 M NaOH. The buffer was used for measurements at pH 2 and pH 6-7 when lithium aluminate was floated. The concentrations of the collectors were between 7.87 μmol / I and 151.86 μmol / I and that of the foaming agent (pine oil) between 1.2*10-3g / L and 1.8*10-2g / L. The natural pH of lithium aluminate was between 10 and 11. The flotation tests were carried out under daylight (>5000 lux), under the action of a R7s halogen lamp (220-240 V, 400 W, 8550 lumens, 2700-3300 kelvin), laser light (390-400 nm) and in the dark (<40 lux). The flotations in the laser light were carried out in a closed box in which the Hamimond tube was installed. The box measures 60 x 60 x 60 cm. In the middle of each of the four walls we installed an aluminum heat sink from Fischer (thermal resistance: 0.7 - 1.65 K / W, dimensions: 200 x 200 x 25 mm) on top of which four LEDs from Avonec (Premium 3W LED, 390-400 nm, colour: UV-A, max. Power: 750 mA, operating voltage: 3.5 V-4.5 V) which were installed via a power supply (APC-16-700, input: 100-240 V, output: +24 V, max. 700 mA, Class 2 power supply). For flotation experiments under halogen lamp irradiation, a headlamp was equipped with a halogen lamp R7s and positioned at a distance of 50 cm from the Halimond tube. For the experiments, samples of 2 g of each mineral (lithium aluminate, gehlenite, spodumene, galaxite or mixtures thereof) were floated and the yields calculated from the ratios of the flotation yield and the remaining material.3.1 Flotations using 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride as collectorFor example, under the conditions that the flotation time was 10 minutes, the concentration of the collector 78.66 μmol / I 1-(2',5 '-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridine, the concentration of the foaming agent 1.2*10-2g / L, the air flow 170 cm3 / min, the pH 10-11, and the flotation was carried out under daylight, 87% of the lithium aluminate could be recovered. Under the conditions that the flotation time was 3 minutes, the concentration of the collector was 7.87 (6) μmol / I 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride chloride, the concentration of the foaming agent was 1.2*10-3g / L, the air flow was 170 cm3 / min and the pH 10-11, the flotation yield was 35.9% lithium aluminate in the dark. Under the same conditions, but in sunlight, the yield of the starting materials was 5.5%. Under the conditions that the flotation time was 3 minutes, the concentration of the collector was 7.87 (6) μmol / L of 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride, the concentration of the foaming agent was 1.2*10-3g / L, the air flow was 170 cm3 / min, the pH value was 2, the recovery rate of lithium aluminate was 43.8% in sunlight and 29.7% in irradiation with R7s light, while the flotation of the gangue of gehlenite was suppressed (recovery rate 4.0% in R7s irradiation and 9.4% in laser light irradiation).Table 1: Results of flotations of lithium aluminate and gehlenite, respectively, in which 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride was used as collector, varying the conditions.pH 2A. ADaylightLiAlO243,8%R7sLiAlO229,7%R7sGehleniten4,0%pH 6-7A. ADarkness DarkLiAlO243,6%DaylightLiAlO238,2%R7sLiAlO226,2%DaylightGehleniten6,6%pH 10-11A. ADarkness DarkLiAlO235,9%DaylightGehleniten5,5%B. BDaylightLiAlO255,4%C. CDaylightLiAlO273,6%D. DDaylightLiAlO287,0%Darkness DarkLiAlO287,7%Hammond tube, content 250 ml, 2,000 g LiAlO2 and gehlenite, respectively;Collector solution 1% in 0.04 M H3BO3 0.04 M H3PO4 and 0.04 M AcOH inWater, pH adjustment by 0.1 M NaOH_NER1948, foaming solution 1% pine oilplus 0.1% of emulsogen M in water; A: conditioning time CT=3 min.,Flotation time FT=3 min, 60 μl collector, 30 μl foaming agent. B: CT=3 min,FT=5 min, 300 μl collector, 150 μl foaming agent; C: as before, but FT=10 min;D: as before, but collector 600 μl, foaming agent 300 μl. The collector was discharged.100 g of aqueous stock solution containing 1% by weight of the solution are taken off.The punicin derivative and 0.15 ml of methanol were added.The table shows the results of first experiments for flotation of the mineral lithium aluminate (LiAlO2) against the gangue gehlenite (Ca2Al[AlSiO7]), varying the pH (2, 6-7, 10-11) and light scenario (1st sun light< 5000 lux; 2nd R7s halogen lamp, 500 W; 3rd darkness< 40 lux). At a pH of 2, significantly different yields are observed in sunlight and under the influence of an R7s lamp (43.8% compared with 29.7%=differential of about 47%), while the gait material gehlenite is suppressed almost completely (4%). At a pH of 6-7, the difference in yield is about 67% (43.6% versus 26.2%), depending on whether lithium aluminate is floated in the dark or in the light of the R7s lamp. After optimizing the flotation conditions, a maximum yield of 87.7% is finally achieved in the dark, while gehlenite is suppressed almost completely.Flotation of lithium aluminate (LiAlO2) using 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride at pH 10-11 using conditions D in the dark:The flotation experiment was carried out in a box 60 x 60 x 60 cm in size with a lid. The 250 ml volume Hammond tube, having a medium pore frit glass through which air could flow into the device, was placed in the center of the box. It was completely wrapped in aluminum foil to conduct an experiment in the dark (<40 lux). In the first step, 2.00 g of lithium aluminate were suspended and stirred at 500 U / min in about 30 ml of distilled water over a period of one minute (=confining time). The collector 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride (78.66 μmol / l) was then added and, after a further minute of conditioning time, the foaming agent (1.2*10-2g / l). After one minute, the remaining volume was made up to 250 ml, the box was sealed to keep the device in the dark, and the air pump was turned on to adjust the air flow to 170 cm3 / min. Thereafter, the floating was carried out for 10 minutes. After this time, the flotate and the remaining residue were separately filtered, dried and weighed to determine the recovery rate which was 87.7%.Table 2: Results of flotations using the punicin derivative having a C10 side chain at the 4-position of pyridine as a collector, varying the conditions.pH 2300 μl of foaming agent82,3%pH 6-776,5%pH 1087,2%150 μl of foaming agent86,9%without foaming agent92,0%Flotations were carried out under daylight, conditioning time CT=3Flotation time FT=10 min, 600 μl of collector taken from a 100 gAn aqueous stock solution containing 1% of the punicin derivative and 0.15 ml of methanol.It is found that in the case of the punicin derivative having a C10 side chain at the 4-position of pyridine, addition of a foaming agent can be omitted and a yield of 92% of the lithium aluminate can be obtained.The selectivity of the punicin derivatives can be used to achieve selective flotations of mixtures of minerals and gangue materials. Thus, after floating a 1:1 mixture by weight of lithium aluminate and gehlenite under optimized conditions (conditioning time=3 min; flotation time=10 min; 78.66 mmol / l of 1-(2',5'-dihydroxyphenyl)-4-[(1E)-hex-1-en-1-yl]pyridinium chloride, 1.2*10-3g / l of pine oil as foaming agent, flotation carried out in daylight), 80% of the weight of the lithium aluminate was floating when a pH of 10-11 was adjusted.3.2 Flotation Processes Using Punicines 1-6 (see Figure 6a)We conditioned the punicins 1-6 each for three minutes with an aqueous suspension of the mineral lithium aluminate at room temperature and the flotation conditions were determined as follows: samples of 2.0 g lithium aluminate (LiAlO2), Hallimond tubes with 250 ml, stirring speed of 500 U / min, air flow rate of 32 cm3 / min for 3 min flotation time, concentration of the collector=8.58 μmol / l, 30 μl pine oil as foaming agent. Flotations were carried out under daylight (3000 lux), UV light (4500 lux, 3 W, 390-400 nm, colour: UV-A, max. Power: 750 mA, operating voltage: 3.5 V-4.5 V) or in the dark. After flotation, the froth product and the remaining solids were filtered off, dried at 80° C. overnight and then weighed. The results are shown in FIG. 6 b. The recovery rates of flotation of LiAlO2ohne any additives (blank), gave recovery rates of 17.82%±3.70 in daylight which changed only slightly within the error interval in UV light and in the dark. The presence of the natural product punicin 1 changed the recovery rates under the above conditions to 23.83%±5.65 (daylight), 28.67%±8.71 (UV irradiation) and 25.63%±9.17 (darkness). The tert-butyl derivative of punicin, collector 2, resulted in recovery rates of 29.72% ± 0.69 (daylight) and 37.68% ± 1.73 (UV irradiation) and 32.89% ± 8.69 in darkness. Collectors 3 and 4 were found to be more sensitive to the lighting conditions than Punicins 1 and 2, and thus the Punicins show considerable differences in their performance in the flotation of lithium aluminate, depending on the substitution pattern and lighting conditions.3.3 Conclusions Are DrawnIt has been shown that even flotation with unsubstituted punicins, i.e. the natural product from punica garnetum, has a measurable and light-dependent influence on the recovery rate of lithium aluminate (see FIG. 6 ). Substituted and unsubstituted punicins can be used as collectors or suppressors depending on flotation conditions. Moreover, a punicin derivative whose two hydroxyl groups each have ester bonds to oleic acid has been found to be less suitable, at least for flotation of the specific target lithium aluminate. Flotation in the presence of sodium oleate as collector without the addition of punicin derivatives gave almost identical recovery rates, irrespective of pH and light scenario, so that the selectivity to a desired mineral in mixtures cannot be adjusted during the flotation process in order to achieve an improved selectivity.3.4 Temperature Dependence and Influence of Conditioning TimeThe flotation of lithium aluminate is best carried out at 1°C or at temperatures above 40°C. Figure 7 shows the recovery rate of lithium aluminate at various temperatures using 4-tert-butyl substituted punicin as collector (8.58 μmol / L). Thus, a recovery rate of 39.05% ± 1.99 was achieved at 1°C, while the minimum was observed at 20°C. As the temperature increased, the values fell back to about 40%.In addition, the conditioning time has a strong influence on the recovery rates. Thus, the maximum recovery rate is achieved after a conditioning time of 60 minutes, as shown in Figure 8 for 4-tert-butyl punicin as an example.4. Flotation Tests with Ylid Derivatives4.1 FlotationThe glass filter used is filled with about 20 ml of deionized water. A sample of 2 g of the mineral to be floated is suspended in the water. The suspended mineral is stirred with a magnetic stirrer at 500 U / min. The mineral suspension is stirred for one minute for conditioning. The desired quantity of the collector is dispensed from a 50 mM methanolic solution of the relevant collector using an air displacement pipette. The mixture of mineral, collector and water is stirred for an additional minute. If necessary, sodium dithionite is added as a freshly prepared 0.5 M aqueous solution as reducing agent using a syringe. After this second conditioning time, the Hamimond tube is made up to about 250 ml with deionized water. A nitrogen flow rate of 32 cm3 / min is adjusted using a rotameter and held at this rate for three minutes. The flotate and the remaining minerals in the Halimond tube are collected separately and collected using a paper filter. The paper filters are dried at 80° C. overnight. The mass of the flotate and the remaining minerals is measured by differential weighing of the filter papers.4.2 Flotations with lithium aluminate and sodium dithionite.In the model experiments, lithium aluminate was floated with the viologenic collector MO-M-055 under various molar ratios of sodium dithionite. The efficiency of the collector can be appreciably influenced by the metering of sodium dithionite as reducing agent. The different yields of lithium aluminate at different collector and dithionite concentrations are shown in Figures 9 and 10.The flotation yield can be influenced by the molar ratio between dithionitions and the collector. At a dosage of 100 equivalents of sodium dithionite, the flotation properties of the collector are greatly reduced. However, the addition of 33.3 equivalents of sodium dithionite leads to a marked increase in the lithium aluminate yield by about 15%.This can be explained by the redox behavior of the viologens. Sodium dithionite can produce a viologen radical cation by reduction which has better adsorption properties. However, a large excess of dithiothreitol can cause a second reduction, greatly affecting the flotation properties of the molecule. _NER1967 - Therefore, a method is presented which can be used to adjust the adsorption properties of a collector in a flotation plant depending on the dosage of sodium dithionite.List of Citations1. Schmidt et al., Studies on photocatalytically active materials containing structure elements of a pyridinium alkaloid from Punica garnetum. Journal of Materials Chemistry 2007, 17, 2793-2800. 2. Albrecht et al., Redox active donor-substituted punicin derivatives. Organic & Biomolecular Chemistry 2009, 7, 1445-1453. 3. Nagoriny et al., Switchable Mesomeric Betaines Derived from Pyridinium Phenates and Bis(thienyl)ethanes. European Journal of Organic Chemistry 2021, 3178-3189. 4. Qiu et al., Improvement of the Fresh Flotation of LiAlO2and liquid solid solution via pre-functionalization. Scientific Reports 2021, 11, 20443. 5. Qiu et al., Influencing the froth flotation of LiAlO2and liquid solid solution with ionic liquids. RSC Advances 2022, 12, 29562-29568. 6. A. Schmidt, T. Mordhorst, M. Nieger, Investigation of a betaine alkaloid from Punica garnetum. Natural Product Research 2005, 19, 541-546. 7. A. Schmidt, T. Mordhorst, Conjugated, cross-conjugated, and pseudo-cross-conjugated derivatives of a pyridinium alkaloid from Punica garnetum. ARKIVOC 2003, XIV, 233-245. 8. A. Schmidt, T. Mordhorst, H. Fleischhauer, G. Jeschke, Coupled photocatalytic electron-transfers with 4,4'-bipyridinium derivatives of a betaine alkaloid from Punica garnetum. ARKIVOC2005, X, 150-164. 9. H. Fleischhauer, L. Frormann, A. Schmidt, Van der Vegetal Ingredient zur Polymer - New Properties According to the Lecture of Nature. Extrusion 2005, 5, 50-51, 10th A. Schmidt, M. Topp, M. Mordhorst, O. Schneider, Redox active derivatives of the betaine-alkaloid Punicine from Punica garnetum. Tetrahedron 2007, 63, 1842-1848. 11. A. Schmidt, M. Albrecht, Photocatalytically Active Materials with Pyridinium enolate Partial Structures. Journal for Natural Research 2008, 63b, 465-472. 12. M. Albrecht, M. Yulikov, T. Kohn, G. Jeschke, J. Adams, A. Schmidt, Pyridinium salts and ylides as partial structures of photoresponsive Merrifield resins. Journal of Materials Chemistry 2010, 20, 3025-3034. 13.M. Albrecht, M. Gjikaj, A. Schmidt, Intermoelcular interactions of punicin derivatives. Tetrahedron 2010, 66, 7149 - 7154. 14. C. F. Otto, C. Herzberger, M. Liu, J. C. Namyslo, M. Nieger, T. Frese, F. Lederle, E. G. Hubner, A. Schmidt, Borane adducts of punicine and of its dehydroxy derivatives (pyridinium-1-yl)-2-and 3-phenates. Tetrahedron 2020, 76, 131627. 15. B. A. Wills, T. Napier-Munn, Mineral processing technology, Elsevier, Amsterdam 2006, 267, pp. 16. R. M. G. Lima, P. R. G. Brandao, A. E. C. Peres, The infrared spectra of amine collectors used in the flotation of iron ores. Miner. Eng. 2005, 18, 267-273. 17. X. Weng, G. Mei, T. Zhao, Y. Zhu, Utilization of novel ester-containing quaternary ammonium surfactant as cationic collector for iron ore flotation. Sep. Purif. Technol. 2013, 103, 187-194. 18. M. Ejtemaei, M. Gharabaghi, M. Iranajad, A review of zinc oxide mineral benefication using flotation method. Adv. Colloid Interface. Sci. 2014, 206, 68-78, 19th S. Aghazadeh, S. K. Mousavinezhad, M. Gharabaghi, Chemical and colloidal aspects of collectionless flotation behavior of sulfide and non-sulfide minerals. Adv. Colloid Interface. Sci. 2015, 225, 203-217. 20. Z. J. Wu, X. M. Wang, H. N. Liu, H. F. Zhang, J. D. Miller, Some physicochemical aspects of water-soluble mineral flotation. Adv. Colloid Interface. Sci. 2016, 235, 190-200. 21. Y. Xing, M. Xu, X. Gui, Y. Cao, B. Bebel, M. Rudolph, S. Weber, M. Kappl, H.-J. Butt, The application of atomic force microscopy in mineral flotation. Adv. Colloid Interface Sci. 2018, 256, 373-392. 22.T.N. Hunter, R.J. Pugh, G.V. Frans, G.J. Jameson, The role of particles in stabilizing foams and emulsions. Adv. Colloid Interface Sci. 2008, 137, 57-81. 23. H. Polat, D. Erdogan, J. Hazard, Heavy metal removal from waste waters by ion flotation. Mater. 2007, 148, 267-273. 24. R. M. Raman, S. Ata, G. J. Jamerson, The effect of flotation variables on the recovery of different particle size fractions in the roth and the pulp. Int. J. Miner. Process. 2012, 106, 70-77. 25th D. Zamboulis, S. Ataroudi, A. Zouboulis, K. Matis, The application of absorptive flotation for the removal of metals. Desalting 2004, 162, 159-168.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Cited Non-Patent LiteratureStudies on photocatalytically active materials containing structure elements of a pyridinium alkaloid from Punica garnetum", Journal of Materials Chemistry 2007, 17, 2793-2800

[0008] "Redox active donor-substituted punicin derivatives", Organic & Biomolecular Chemistry 2009, 7, 1445-1453

[0009] Switchable Mesomeric Betaines Derived from Pyridinium Phenates and Bis(thienyl)ethane", European Journal of Organic Chemistry 2021, 3178-3189

[0010] Improvement of the Fresh Flotation of LiAlO2 and Melilite Solid Solution via Characterization", Scientific Reports 2021, 11, 20443

[0011] Influencing the frozen flotation of LiAlO2 and melilite solid solution with ionic liquids", RSC Advances 2022, 12, 29562-29568

[0011] Investigation of a betaine alkaloid from Punica garnetum", Natural Product Research 2005, 19, 541-546

[0014] A. Schmidt, T. Mordhorst, "Conjugated, cross-conjugated, and pseudo-cross-conjugated derivatives of a pyridinium alkaloid from Punica garnetum", ARKIVOC 2003, XIV, 233-245

[0015] A. Schmidt, T. Mordhorst, H. Fleischhauer, G. Jeschke, "Coupled photocatalytic electron-transfers with 4,4'-bipyridinium derivatives of a betaine alkaloid from Punica garnet", ARKIVOC 2005, X, 150-164

[0015] H. Fleischhauer, L. Frormann, A. Schmidt, "Van der Vegetal Ingredient zur Polymer-Neuen Resititute der Naturbeit", Extrusion 2005, 5, 50-51

[0015] A. Schmidt, M. Albrecht, T. Mordhorst, M. Topp, G. Jeschke, "Studies on photocatalytically active materials containing structure elements of a pyridinium alkaloid from Punica garnet", Journal of Materials Chemistry 2007, 17, 2793-2800

[0015] A. Schmidt, M. Topp, M. Mordhorst, O. Schneider, "Redox active derivatives of the betaine-alkaloid Punicine from Punica garnet", Tetrahedron 2007, 63, 1842-1848

[0015] A. Schmidt, M. Albrecht, "Photocatalytically Active Materials with Pyridinium enolate Partial Structures", journal for Natural Research 2008, 63b, 465-472

[0015] M. Albrecht, O. Schneider, A. Schmidt, "Redox-active donor-substituted punicin derivatives", Organic and Biomolecular Chemistry 2009, 7, 1445-1453

[0015] M. Albrecht, M. Yulikov, T. Kohn, G. Jeschke, J. Adams, A. Schmidt, "Pyridinium salts and ylides as partial structures of photoresponsive Merrifield resins", Journal of Materials Chemistry 2010, 20, 3025-3034

[0015] M. Albrecht, M. Gikaj, A. Schmidt, "Intermolecular interactions of punicin derivatives", Tetrahedron 2010, 66, 7199-7154

[0015] C. F. Otto, C. Herzberger, M. Liu, J. C. Namyslo, M. Nieger, T. Frese, F

[0015] Lederle, E. G. Hübner, A. Schmidt, "Borane adducts of punicine and of its dehydroxy derivatives (pyridinium 1-yl)-2-and 3-phenates", Tetrahedron 2020, 76, 131627

[0016] B. A. Wills, T. Napier-Munn, Mineral processing technology, Elsevier, Amsterdam 2006, 267 pp [0122, 0185]R.M.G. Lima, P.R.G. Brandao, A.E.C. Peres, Miner. Eng. 2005, 18, 267-273

[0122] X. Klein, G. Mei, T. Zhao, Sep. Purif. Technol. 2013, 103, 187-194

[0122] M. Ejtemaei, M. Gharabaghi, M. Irannajad, Adv. Colloid Interface. Sci. 2014, 206, 68-78

[0122] S. Aghazadeh, S. K. Mousavinezhad, M. Gharabaghi, Adv. Colloid Interface. Sci. 2015, 225, 203-217

[0122] Wu, Z.J., Wang, X.M., Liu, H.N., Zhang, H.F., Miller, J.D., Adv. Colloid Interface. Sci. 2016, 235, 190-200

[0122] Y. Xing, M. Xu, X. Gui, Y. Cao, B. Bebel, M. Rudolph, S. Weber, M. Kappl, H.-J. Butt, Adv. Colloid. Interface Sci. 2018, 256, 373-392

[0122] T. N. Hunter, R. J. Pugh, G. V. Frans, G. J. Jameson, Adv. Colloid Interface Sci. 2008, 137, 57-81

[0122] H. Polat, D. Erdogan, J. Hazard. Mater. 2007, 148, 267-273

[0122] R.M. Raman, S. Ata, G.J. Jamerson, Int. J. Miner. Process. 2012, 106, 70-77

[0122] D. Zamboulis, S. Ataroudi, A. Zouboulis, K. Matis, Desalination 2004, 162, 159-168

[0122] Schmidt et al., Studies on photocatalytically active materials containing structure elements of a pyridinium alkaloid from Punica garnetum. Journal of Materials Chemistry 2007, 17, 2793-2800

[0185] Albrecht et al., Redox active donor-substituted punicin derivatives. Organic & Biomolecular Chemistry 2009, 7, 1445-1453

[0185] Nagory et al., Switchable Mesomeric Betaines Derived from Pyridinium Phenates and Bis(thienyl)ethanes. European Journal of Organic Chemistry 2021, 3178-3189

[0185] Qiu et al., Improvement of the Fresh Flotation of LiAlO2and melilite solid solution via pre-functionalization. Scientific Reports 2021, 11, 20443

[0185] Qiu et al., Influencing the froth flotation of LiAlO2and liquid solid solution with ionic liquids. RSC Advances 2022, 12, 29562-29568

[0185] A. Schmidt, T. Mordhorst, M. Nieger, Investigation of a betaine alkaloid from Punica garnetum. Natural Product Research 2005, 19, 541-546

[0185] Schmidt, A., Mordhorst, T., Conjugated, cross-conjugated, and pseudo-cross-conjugated derivatives of a pyridinium alkaloid from Punica garnetum. ARKIVOC 2003, XIV, 233-245

[0185] A. Schmidt, T. Mordhorst, H. Fleischhauer, G. Jeschke, Coupled photocatalytic electron-transfers with 4,4'-bipyridinium derivatives of a betaine alkaloid from Punica garnetum. ARKIVOC2005, X, 150-164

[0185] H. Fleischhauer, L. Frormann, A. Schmidt, Van der Vegetal Ingredient zur Polymer--New Properties According to Natural Precursor. Extrusion 2005, 5, 50-51

[0185] Schmidt, A., Topp, M., Mordhorst, M., Schneider, O., Redox active derivatives of the betaine-alkaloid Punicine from Punica garnetum. Tetrahedron 2007, 63, 1842-1848

[0185] Schmidt, A., Albrecht, M., Photocatalytically Active Materials with Pyridinium enolate Partial Structures. Journal for Natural Research 2008, 63b, 465-472

[0185] M. Albrecht, M. Yulikov, T. Kohn, G. Jeschke, J. Adams, A. Schmidt, Pyridinium salts and ylides as partial structures of photoresponsive Merrifield resins. Journal of Materials Chemistry 2010, 20, 3025-3034

[0185] M. Albrecht, M. Gikaj, A. Schmidt, Intermoelcular interactions of punicin derivatives. Tetrahedron 2010, 66, 7149 - 7154

[0185] C. F. Otto, C. Herzberger, M. Liu, J. C. Namyslo, M. Nieger, T. Frese, F. Lederle, E. G. Hübner, A. Schmidt, Borane adducts of punicine and of its dehydroxy derivatives (pyridinium-1-yl)-2-and 3-phenates. Tetrahedron 2020, 76, 131627

[0185] R.M.G. Lima, P.R.G. Brandao, A.E.C. Peres, The infrared spectra of amine collectors used in the flotation of iron ores. Miner. Eng. 2005, 18, 267-273

[0185] X. Weng, G. Mei, T. Zhao, Y. Zhu, Utilization of novel ester-containing quaternary ammonium surfactant as cationic collector for iron ore flotation. Sep. Purif. Technol. 2013, 103, 187-194

[0185] M. Ejtemaei, M. Gharabaghi, M. Irannajad, A review of zinc oxide mineral benefication using flotation method. Adv. Colloid Interface. Sci. 2014, 206, 68-78

[0185] S. Aghazadeh, S.K. Mousavinezhad, M. Gharabaghi, Chemical and colloidal aspects of collectionless flotation behavior of sulfide and non-sulfide minerals. Adv. Colloid Interface. Sci. 2015, 225, 203-217

[0185] Wu, Z.J., Wang, X.M., Liu, H.N., Zhang, H.F., Miller, J.D., Some physicochemical aspects of water-soluble mineral flotation. Adv. Colloid Interface. Sci. 2016, 235, 190-200

[0185] Y. Xing, M. Xu, X. Gui, Y. Cao, B. Bebel, M. Rudolph, S. Weber, M. Kappl, H.-J. Butt, The application of atomic force microscopy in mineral flotation. Adv. Colloid Interface Sci. 2018, 256, 373-392

[0185] T.N. Hunter, R.J. Pugh, G.V. Frans, G.J. Jameson, The role of particles in stabilizing foams and emulsions. Adv. Colloid Interface Sci. 2008, 137, 57-81

[0185] H. Polat, D. Erdogan, J. Hazard, Heavy metal removal from waste waters by ion flotation. Mater. 2007, 148, 267-273

[0185] R.M. Raman, S. Ata, G.J. Jamerson, The effect of flotation variables on the recovery of different particle size fractions in the roth and the pulp. Int. J. Miner. Process. 2012, 106, 70-77

[0185] D. Zamboulis, S. Ataroudi, A. Zouboulis, K. Matis, The application of absorptive flotation for the removal of metals. Desalting 2004, 162, 159-168

[0185]

Claims

Use of a compound as collector for the selective flotation of lithium minerals, characterized in that the compound is represented by formula (1): A - B ; wherein A is a) aromatic group substituted with one or more OH and / or SH groups, or b) aromatic group bonded to B via a methylene group of formula -[CH 2]- or a methylene carbanion group of formula -[CH -]- ; wherein B is i) a pyridinium or benzoannellated pyridinium compound, wherein A is bonded to the nitrogen atom of the pyridinium or benzoannellated pyridinium compound, or ii) a substituted or unsubstituted pyridyl or benzoannellated pyridyl group; wherein the selective flotation of lithium minerals is carried out using a conditioning time CT≥3 min, preferably >5 min, particularly preferably >10 min, and / or wherein the selective flotation of lithium minerals is carried out at a temperature ≤ 10° C. or ≥ 25° C., preferably ≤ 5° C. or ≥ 40° C.The use of claim 1, wherein the lithium minerals are selected from the group consisting of lithium aluminate, spodumene, chalcopyrite, monazite, galaxite, lithium carbonate, lithium oxide, and combinations thereof.The use according to claim 2 or 3, wherein the selective flotation of lithium minerals is carried out at a pH > 7, preferably at a pH below 10.The use according to any one of the preceding claims, wherein A is represented by formula (2) or (3): ; wherein the dashed line represents the bond to B; wherein R 1 is selected from: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, copperrone and guanidine, wherein R k and R L are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k and R L optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, preferably R 1 is selected from: OH and Br; wherein R 2, R 3, R 4, R 5, R 6, R7, R8, R9 are independently selected from the group consisting of: OH, NH2, SH, CF3, CN, c(o)nh_ner35_, c(o)h, c(o)oh, halogen, preferably Br, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 Rk,OS(O)ORk, OS(O)2Rk,ORk, N(Rk)(RL), p(o)(or_ner53_)(or_ner54_), op(o)(or_ner55_)(or_ner56_), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, wherein Rk, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C4-12heteroaryl groups; wherein R 10= -[ CH 2]- or R 10= -[ CH -]-; and / or wherein B is represented by formula (4) or (5): ; wherein the dashed line represents the bond to A; wherein R 11, R 12, R 13, R 14, R 15, R16, R17, R18, R19 are independently selected from: OH, NH2, SH, CF3, CN, c(o)nh_ner97_, c(o)h, c(o)oh, halogen, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 Rk,OS(O)ORk, OS(O)2Rk,ORk, N(Rk)(RL), p(o)(or_ner115_)(or_ner116_), op(o)(or_ner117_)(or_ner118_), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, R 11, R 12 are preferably independently selected from: H, C 1-12- hydrocarbon group, acyl group having a C 1-12- hydrocarbon group, halogen, substituted or unsubstituted C 4-12- heteroaryl groups, C(O)N(R k)( R L), particularly preferably R 11, R 12 are independently selected from: H, methyl, tert-butyl group, C(O)Me, unsubstituted C 10- alkyl, and hex-1-enyl, Cl, C(O)N(H)(hexyl), hexadecyl-4'-pyridinium, wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- alkenyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.The use according to any one of the preceding claims, wherein the compound used as collector for the selective flotation of lithium minerals is represented by formula (6) or formula (7): wherein R 1 is selected from: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, Copperron and guanidine, preferably R 1 is selected from: OH and Br; wherein R 2, R 3, R 4, R 5, R 6, R 7, R 8, are independently selected from the group consisting of: OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, preferably Br, R k, SR k, S(O)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 Rk,OS(O)ORk, OS(O)2Rk,ORk, N(Rk)(RL), P(O)(ORk)(ORL), op(o)(or_ner194_)(or_ner195_), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, preferably R2, R3, R 4 are selected from the group consisting of: H, OH, Br; wherein R 10= -[ CH 2]- or R 10= -[ CH -]-; wherein R 11, R 12, R 13, R 14, R 15 are independently selected from: OH, NH2, SH, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, Rk, SRk, s(o)R k, S(O) 2 R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 R k, OS(O)OR k, OS(O)2Rk,ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, preferably R11, R12independently of one another are selected from: H, C1-12hydrocarbon group, Acyl group having a C 1-12- hydrocarbon group, halogen, preferably R 11, R 12 are independently selected from: H, methyl, tert-butyl group, COMe, unsubstituted C 10- alkyl, and hex-1-enyl, Cl wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, A substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl group, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.The use according to any one of the preceding claims, wherein the compound used as collector for the selective flotation of lithium minerals is represented by formula (7): wherein R 1 is selected from: OH, halogen, preferably Br, SH, NH 2, S(O) 2 OH, OP(O)(OH)(OH), OC(S)SH, OP(S)(OH)SH OC(O)NH-OH, OC(S)N(R L) R k, SC(O)N(R L) R k, sc(s)n(R L) R k, NH-OH, Copperrone, and guanidine, preferably R 1 is selected from: OH and Br; wherein R 2, R 3, R 4 are independently selected from the group consisting of: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, preferably Br, R k, SRk, S(O)Rk, s(o)_ner295_R k, S(O)OR k, S(O) 2 OR k, OS(O)R k, OS(O) 2 R k, OS(O)OR k, OS(O) 2 R k, ORk, N(Rk)(RL), P(O)(ORk)(ORL), OP(O)(ORk)(ORL), SiR k R L R m, C(O)R k, C(O)OR k, C(O)N(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(Rk)RL, preferably R2, R3, R4 are independently selected from the group consisting of: H, OH, Br; wherein R 11, R 12, R 13, R 14, R 15 are independently selected from: OH, NH 2, SH, CF 3, CN, C(O)NH 2, C(O)H, C(O)OH, halogen, R k, SR k, S(O)Rk, S(O)2Rk, S(O)ORk, S(O)2ORk, os(o)R k, OS(O) 2 R k, OS(O)OR k, OS(O) 2 R k, OR k, N(R k)( R L), P(O)(OR k)( ORL), OP(O)(ORk)(ORL), SiRkRLRm, C(O)Rk, C(O)ORk, c(o)n(R L) R k, OC(O)R k, OC(O)R k, OC(O)OR k, and OC(O)N(R k) R L, preferably R 11, R 12 are independently selected from: H, C 1-12- hydrocarbon group, acyl group with a C1-12hydrocarbon group, halogen, preferably R11, R12 are independently selected from: H, methyl, tert-Butyl group, COMe, unsubstituted C 10- alkyl, and hex-1-enyl, Cl wherein R k, R L and R m are independently selected from H and substituted or unsubstituted C 1-25- alkyl, substituted or unsubstituted C 1-25- heteroalkyl, substituted or unsubstituted C 6-14- aryl or substituted or unsubstituted C 4-12- heteroaryl groups, wherein two or more of R k, R L and R m optionally together form one or more substituted or unsubstituted C 6-4- aryl or substituted or unsubstituted C 4-12- heteroaryl groups.A flotation composition comprising the collector defined in any one of claims 1 to 6.A flotation process comprising the steps of: a) providing a suspension of a mixture of at least two types of particulate materials in a solvent, preferably water; b) combining the flotation composition of claim 7 with the suspension of step a); c) conditioning the mixture of step b) for a conditioning time to form one or more types of particulate materials on the surface of which at least a portion of the collector comprised by the flotation composition of claim 7 is enriched; d) adjusting the mixture of step c) to a temperature; e) introducing a flotation gas for forming a flotation foam at the surface of the solvent, wherein the flotation foam comprises a part of the particulate materials which are to be separated from the remaining part of the particulate materials, f) separating the flotation foam from the suspension; wherein the particulate materials comprise lithium minerals and gangue materials; wherein the selective flotation of lithium minerals is carried out using a conditioning time CT ≥ 3 min, preferably > 5 min, particularly preferably > 10 min, and / or wherein the selective flotation of lithium minerals is carried out at a (flotation) temperature ≤ 10° C. or ≥ 25° C., preferably ≤ 5° C. or ≥ 40° C.The flotation process of claim 8, wherein step c), step d) and step e) further comprise i) performing an exposure or exclusion of light to switch the collector; and / or ii) increasing or decreasing the pH of the suspension to switch the collector.The flotation method according to claim 8 or 9, wherein the exposure or the exclusion of light and / or the pH value is adjusted depending on the lithium minerals and / or gangue materials.

Images