Benefitiation of lithium-bearing ore

Abstract

The present invention relates to a use of collector composition for the beneficiation of lithium-containing minerals from an ore, and the process for beneficiation of lithium-containing minerals using said collector composition.

Description

[0001]BENEFITIATION OF LITHIUM–BEARING OREFIELD OF THE INVENTIONThe present invention relates to a collector composition for thebeneficiation of lithium–containing minerals, from an ore, theiruse in flotation processes and the process for beneficiation oflithium containing minerals using said collector composition.STATE OF ARTLithium is an important strategic resource substance which iswidely applied to emerging fields of batteries, ceramics, glass, lubricants, refrigerants, nuclear industry, photoelectricity and the like, and is an indispensable important raw material of modern high-tech products. In recent years, the continuous developmentof high and new technologies, growth of lithium battery electricvehicles and lithium battery mobile electronic products,lithium and lithium salt products are more and more widely applied,and the demand of the international market for thelithium products is continuously increasing.Lithium does not occur in elemental form in nature because of its reactivity. However, there are more than 100 known minerals that may contain lithium, although only a few of these are currently economic to extract. The most common lithium-bearing minerals found in economic deposits are Spodumene, Lepidolite, Petalite, Eucryptite, Amblygonite, Hectorite, Bikitaite, Zinnwaldite, andJadarite. Among them, due to its high lithium content, spodumeneis considered the most important lithium ore mineral. A typical run of mine ore can contain 0,5-2% LiO, while a typical Spodumene concentrate suitable for lithium carbonate production contains5,5-7% LiO (68% - 87% spodumene). Higher grade concentrates with7.6% LiO and low iron content are used in ceramics and more demanding industries.Nowadays, global resources of lithium have been estimated to beapproximately 41 million tons, with the largest resources held byBolivia, Chile, Argentina, the USA, China, Brazil, Portugal,Zimbabwe and Australia. Spodumene which is basically LiAlSiOcontains approximately 8% LiO and is the most abundant lithium-containing mineral. Spodumene is associated with other gangueminerals, such as feldspar, quartz and muscovite, from which itmust be separated to be useable in chemical and ceramic applications.Global supply of lithium is currently sourced from brines or hardrock deposits. In the former, lithium is concentrated as solublesalts by solar evaporation. Lithium produced from brines isgenerally of a low grade and, while the capital input for brine production is high, operating costs are low. In the case of hard rock deposits conventional mining and beneficiation techniques are used to produce high grade spodumene concentrate or other mineral concentrates in which the grade isgreater than that of the parent are. It is possible toobtain lithium chemicals of technical, battery grade (99.5%) fromvarious acid-roasting and lime-roasting processes.It is well-known from the state of the art to separate the valuableminerals from gangue minerals by using flotation. The mineral, which can be dry ground, but preferably wet-ground, is previously crumbled and suspended in water for the flotation. Collectors are normally added to the mineral, frequently in combination with foaming agents and where appropriate, other auxiliary reagents such as regulators, depressors (deactivators) and / or enhancers (activators), to favor the separation of the valuable minerals from the unwanted mineral gangue components in the subsequent flotation. These reagents are usually allowed to act for a certain time on the finely ground (conditioned) mineral before insufflating air into the suspension (flotation) so as to generate a froth. In this case, the collector is in charge of causing a hydrophobization of the surface of the minerals such that these minerals are adhered to the gas bubbles formed during the air insufflation. The hydrophobization of the mineral components is carried out selectively such that the mineral components which are not to be floated are not adhered on the gasbubbles. The froth containing the mineral is separated andsubsequently prepared. The object of the flotation is to separate the valuable mineral from the minerals with the highest possible yield, and to simultaneously obtain, in this case, the bestpossible enrichment. Flotation comprises differentiatedprocesses, such as direct or reverse flotation. In directflotation the desired minerals are collected in the froth whilethe unwanted minerals remains dispersed. In reverse or inverseflotation the unwanted minerals are collected in the froth andthe desired minerals remain dispersed in the flotation cellunderflow.The beneficiation of lithium-containing minerals such asSpodumene, Lepidolite, Petalite, Eucryptite, Amblygonite,Hectorite, Bikitaite, Zinnwaldite, Elbaite and Jadarite from theirassociated gangue minerals (e.g., quartz(SiO) and iron oxides(FeO,FeO) is difficult due to their similar surface chemicalproperties. Due to the fact that most lithium deposits in the world are deposits that also contain silicates, the selective separation oflithium containing minerals from their associated gangue minerals(e.g. quartz (SiO) and iron oxide (FeO and FeO) is a processthat has been intensively studied.Anionic surfactants are used as collectors in known processes forthe beneficiation lithium containing minerals, such as fattyacids. Known anionic collectors are, for example, saturated andunsaturated fatty acids, oleic acid fatty acids, linoleic acids,linolenic acids, resin acids, tall oil fatty acids, phosphoricesters, especially optionally alkoxylated phosphoric esters derived from fatty alcohols or from fatty alcohol mixtures, alkyl sulfates, especially alkyl sulfates derived from fatty alcohols or from fatty alcohol mixtures, alkylaryl sulfonates, alkyl sulfosuccinates, alkylsulfosuccinimates and acyl lactylates.WO2021038017 describes a collector composition, comprising atleast one component a) selected from N-oleoyl sarcosine; and atleast one component b) selected from the group consisting ofdi(isononyl)phthalate, di(2-ethylhexyl)phthalate, di(2- propylheptyl) phthalate, di(isononyl)adipate, di(2- ethylhexyl)adipate, di(2-propylheptyl)adipate and isotridecanol for the beneficiation of lithium silicates and magnesium silicates from an ore comprising different silicate minerals, their use in flotation processes and a method for the beneficiation of lithiumsilicates- and magnesium silicates- containing minerals using saidcollector composition. The use of fatty acids as collector / co-collector for the beneficiation of lithium ores is known in the literature. However high doses of the collector compositions and long conditioningtimes are required. There are several other flotation processeswhich are disclosed in literature for the beneficiation of lithium. However, none of the known techniques is sufficient to produce aneconomically viable solution for the beneficiation of lithium ore.From the state of art set forth above, it can be seen that thereis still a need of improvement in the field of beneficiation oflithium containing minerals such as lithium silicates,particularly spodumene, from an ore, in which collectors for thebeneficiation of lithium containing minerals from gangue mineralsare used. Thus, it is an object of the present invention to provide a collector composition that can be used to produce high-gradelithium-containing minerals which can be isolated in high yieldwith high recovery and with low iron content, as well as goodwettability, water dispersibility and suitable froth. SUMMARY OF THE INVENTIONThe inventors have surprisingly found the use of collectors forbeneficiation of lithium-containing minerals from an orecomprising lithium-containing minerals and gangue minerals. Saidcollectors are useful for the separation of lithium containingminerals, such as lithium silicates, from gangue minerals. Thesecollectors allow obtaining a good efficiency and purity, as wellas good wettability, water dispersibility and suitable froth.Thus, the first aspect of the present invention relates to use ofa collector composition for the beneficiation of lithium-containing minerals, in particular lithium silicates, from an orecomprising lithium-containing minerals and gangue minerals,wherein the collector composition comprises:a) at least an ether carboxylic acid or salts thereof representedby formula (I) R-O-P-CH-COOX (I) wherein, R is a linear or branched alkyl or alkenyl chain having from 4 to 30 carbon atoms;P consists of n units of –(CHCHO)- and / or an m units of –(CHCHRO)- or –(CHRCHO)- and / or an q units of –(CHCHRO)- or –(CHRCHO)-, wherein n, m and / or q represent independently a numberwithin the range of 0 to 25, and wherein the sum of n+m+q is from1 to 25; and X is H or a cation selected from the group of an alkali metal, analkaline earth metal, ammonium and alkylammonium; andb) a fatty acid or mixtures of fatty acids.Processes for the preparation of collector compositions as definedin the first aspect are also an object of the invention.It is also part of the object of the invention, a process for thebeneficiation of lithium-containing minerals, from an orecomprising lithium-containing minerals and gangue minerals,wherein collector compositions according to the first aspect areused. Another object of the invention is a collector composition as defined in the first aspect, wherein the characterized in that the weight ratio between component a) and component b) is comprised between 99:1 and 1:99. DETAILED DESCRIPTION OF THE INVENTION The term “ore comprising lithium-containing minerals” refers tomineral ores with one or more lithium minerals, such as lithiumsilicates. Typically this ores are associated with a wide arrayof gangue minerals that generally consist of silicates (SiO) andiron oxide (FeO and FeO) in varying amounts. The amount oflithium-containing minerals and gangue as well as the type ofgangue present in the ore can vary widely for different ore types. The present invention is thus applicable to lithium bearing ores regardless of the lithium content or nature of lithium mineral or minerals and regardless of gangue content. The term “lithium-containing mineral” refers to any mineral that contains lithium. Suitable examples of lithium containing mineralsare spodumene (LiAlSiO), petalite ( LiAlSiO ), eucryptite(LiAlSiO), lepidolite (KLiAlSiO (F,OH))), hectorite(Na (Mg,Li)SiO (OH)), bikitaite (LiAlSiO·HO), zinnwaldite(KLiFeAlSiO (F,OH)), and amblygonite (LiAlPO)), preferablyspodumene. The term “ore” refers to aggregates of rocks from which the desired minerals are extracted. The term “gangue” refers herein to those mineral materials which are of little or no value and need to be separated from the valuedminerals (i.e. lithium-containing minerals). Examples of gangueminerals contained in lithium ores are silicates (SiO) and ironoxide (FeO and FeO). The term “beneficiation” refers herein to the separation process which removes the gangue minerals from an ore to produce a highergrade concentrate. For example lithium is extracted from lithiumore. Beneficiation includes crushing, grinding, gravityconcentration, magnetic separation and flotation concentration.COLLECTOR COMPOSITION:The present invention discloses use of a collector composition forthe beneficiation of lithium-containing minerals, from an orecomprising lithium-containing minerals and gangue minerals,wherein the collector composition comprises: a) at least an ether carboxylic acid or salts thereof represented by formula (I) R-O-P-CH-COOX (I) wherein, R is a linear or branched alkyl or alkenyl chain having from 4 to 30 carbon atoms;P consists of n units of –(CHCHO)-, and / or m units of –(CHCHRO)-or –(CHRCHO)-, and / or q units of –(CHCHRO)- or –(CHRCHO)-, wherein n represents a number within the range of 0 to 25, mrepresents a number within the range of 0 to 25, and q representsa number within the range of 0 to 25, and the sum of n+m+qrepresents a number from 1 to 25; R represents a –CH group; andR represents a –CHCH group; X is H or a cation selected from the group of an alkali metal, analkaline earth metal, ammonium and alkylammonium; andb) a fatty acid or mixtures of fatty acids.In a preferred embodiment according to the present invention thelithium-containing minerals, in particular lithium silicateminerals, are selected from the group consisting of spodumene,petalite, lepidolite, bikitaite, zinnwaldite and hectorite; morepreferably from the group consisting of spodumene and petalite;and still more preferably spodumene.Said collector composition allows obtaining improved recovery,yield and higher purity of the lithium containing minerals,compared to known collectors, and at the same time, has anincreased wettability and water dispersibility properties as wellas a suitable froth.Ether Carboxylic acids or salts thereof (a)The collector composition according to the present inventioncomprises a component (a), said component is at least an ethercarboxylic acid or salts thereof of formula (I): R-O-P-CH-COOX (I) wherein, R is a linear or branched alkyl or alkenyl chain having from 4 to 30 carbon atoms;P consists of n units of –(CHCHO)-, and / or of m units of –(CHCHRO)- or –(CHRCHO)-, and / or of q units of –(CHCHRO)- or –(CHRCHO)-, wherein n represents a number within the range of 0 to 25, m represents a number within the range of 0 to 25 and q represents a number within the range of 0 to 25, and wherein the sum of n+m+q represents a number from 1 to 25; R represents a –CH group; and R represents a –CHCH group; andX is H or a cation selected from the group of an alkali metal, analkaline earth metal, ammonium and alkylammonium.In the context of the present invention, the term “alkyl” refersto a straight or branched hydrocarbon chain containing theindicated number of carbon atoms, such as from 4 to 30 carbonatoms.In the context of the present invention, the term “alkenyl” refersto a linear hydrocarbon chain containing the indicated number ofcarbon atoms, such as from 4 to 30 carbon atoms, and from 1 to 3double bonds. In the context of the present invention, the term “alkali metal” refers to any of lithium (Li), sodium (Na), potassium (K),rubidium (Rb) and cesium (Cs), preferably any of sodium andpotassium. In the context of the present invention, the term “alkaline earth metal” refers to any of beryllium (Be), magnesium (Mg), calcium(Ca), strontium (Sr) and barium (Ba), preferably any of magnesiumand calcium. In the context of the present invention, the term “ammonium” refers to NH . In the context of the present invention, the term “alkyl ammonium” refers to a quaternary ammonium substituted by 1, 2 or 3 alkyl groups as defined herein. In particular, each alkyl group has from 1 to 30 carbon atoms. Examples of alkylammonium aredimethyloctylammonium, dimethyldecylammonium, dimethyllauryl-ammonium, dimethylmyristylammonium, dimethylpalmitylammonium,dimethylcetylammonium, dimethylstearylammonium, dimethylbehenyl-ammonium, or mixtures thereof. Other suitable alkylammonium aremethyldioctylammonium, methyldidecylammonium, methyldilauryl-ammonium, methyldimyristylammonium, methyldipalmitylammonium,methyldicetylammonium, methyldistearylammonium, methyldibehenyl- ammonium, or mixtures thereof. As used herein, the term “salt” refers to the carboxylate anion of the compound of formula (I) as defined herein (i.e. R-O-P- CHCOO) and a suitable cation selected from the groups of an alkali metal (such as Na and K), an alkaline earth metal (suchas Ca and Mg , ammonium and alkylammonium In a preferredembodiment of the present invention, salts of ether carboxylicacid represented by formula (I) are sodium salt or potassium saltof the ether carboxylic acid of the compound of formula (I), i.e.wherein X is Na or K. As used herein, the term “at least an” refers to at least one, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.In one embodiment according to the present invention, R is alinear or branched alkyl containing 4 to 30 carbon atoms or alinear or branched alkenyl group containing 4 to 30 carbon atomsand from 1 to 3 double bonds;In another embodiment according to the present invention, R is alinear or branched alkyl containing 10 to 30 carbon atoms or alinear or branched alkenyl group containing 10 to 30 carbon atomsand from 1 to 3 double bonds; preferably the alkyl or alkenylcontains 10 to 22 carbon atoms, more preferably 12 to 18 carbonatoms, still more 12 to 16 carbon atoms, even more preferably from12 to 14 carbon atoms. In another embodiment of the present invention, R is a linear orbranched alkyl or a linear alkenyl derived from natural fats andoils. Preferred fats and oils include palm oil, coconut oil,sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil;animal fat such as tallow, fish oil, hardened oils and semihardened oils thereof, and mixtures thereof. In a preferred embodiment, R is a linear or branched alkyl or a linear alkenyl derived from palm oil or coconut oil.In a particular embodiment according to the present invention, Ris a linear or branched alkyl group containing 10 to 30 carbonatoms or a linear alkenyl group containing 10 to 30 carbon atomsand from 1 to 3 double bounds; preferably from 10 to 22 carbonatoms, more preferably from 12 to 18 carbon atoms, still morepreferably from 12 to 16 carbon atoms, even more preferably from12 to 14 carbon atoms. In another particular embodiment, R is a linear alkyl groupcontaining 10 to 30 carbon atoms; preferably from 10 to 22 carbonatoms, more preferably from 12 to 18 carbon atoms, still morepreferably from 12 to 16 carbon atoms, even more preferably from12 to 14 carbon atoms. In an embodiment according to the present invention, P consistsof n units of –(CHCHO)-, and / or of m units of –(CHCHRO)- or –(CHRCHO)-, and / or of q units of –(CHCHRO)- or –(CHRCHO)-,wherein n represents a number within the range of 0 to 25; mrepresents a number within the range of 0 to 25; q represents a number within the range of 0 to 25. When n is 0, there are noethylene oxide units in the ether carboxylic acids or salt thereofof formula (I). When m is 0, there are no propylene oxide unitsin the ether carboxylic acids or salt thereof of formula (I). Whenq is 0, there are no butylene oxide units in the ether carboxylicacids or salt thereof of formula (I). In the ether carboxylicacids or salt thereof of formula (I) there is at least one alkyleneoxide unit which is an ethylene oxide, propylene oxide or butylene oxide. The alkoxylation degree is the sum of ethylene oxide, propylene oxide, and butylene oxide units that are present in theether carboxylic acids or salt thereof of formula (I), i.e. thesum of n+m+q, and which is preferably a number from 1 to 25.In another embodiment according to the present invention, Pconsists of n units of –(CHCHO)-, and / or of m units of –(CHCHRO)- or –(CHRCHO)-, and / or of q units of –(CHCHRO)- or –(CHRCHO)-, wherein n represents a number within the range of 0to 15 preferably 0 to 10, more preferably from 0 to 6; m representsa number within the range of 0 to 15, preferably 0 to 10, morepreferably from 0 to 6; q represents a number within the range of0 to 15, preferably 0 to 10, more preferably from 0 to 6. When nis 0, there are no ethylene oxide units in the ether carboxylicacids or salt thereof of formula (I). When m is 0, there are nopropylene oxide units in the ether carboxylic acids or salt thereof of formula (I). When q is 0, there are no butylene oxideunits in the ether carboxylic acids or salt thereof of formula(I). In the ether carboxylic acids or salt thereof of formula (I)there is at least one alkylene oxide unit which is an ethylene oxide, propylene oxide or butylene oxide. The alkoxylation degreeis the sum of ethylene oxide, propylene oxide, and butylene oxideunits that are present in the ether carboxylic acids or saltthereof of formula (I), i.e. the sum of n+m+q, and which is anumber from 1 to 15, preferably from 1 to 10, more preferably from1 to 6, still more preferably from 1 to 3.As explained above, in the present invention the ether carboxylicacids or salts thereof according to Formula (I) are ethoxylatedand / or propoxylated and / or butoxylated, i.e. P is an ethoxy and / orpropoxy and / or butoxy group. The order of the sequence of ethyleneoxide and / or propylene oxide and / or ethylene oxide groups are notcritical for the invention. Therefore, both the ether carboxylicacids or salts thereof according to formula (I) containingethylene oxide groups and / or propylene oxide groups and / orbutylene oxide groups in separate blocks and those ethercarboxylic acids or salts thereof according to formula (I)comprising ethylene oxide and / or propylene oxide and / or butyleneoxide groups are randomly distributed can be used in thecompositions according to the invention. In an embodiment according to the present invention, P consistsof n units of –(CHCHO)- wherein n represents an integer numberfrom 1 to 15, preferably from 1 to 10, more preferably from 1 to6, still more preferably from 1 to 3; m and q represent 0, andthe sum of n+m+q represents a number from 1 to 15, preferably from 1 to 10, more preferably from 1 to 6, still more preferably from 1 to 3. In an embodiment according to the present invention, P consistsof m units of –(CHCHRO)- or –(CHRCHO)- wherein m represents anumber within the range of 1 to 15 preferably 1 to 10, morepreferably from 1 to 6, still more preferably from 1 to 3; and nand q represents 0, and the sum of n+m+q represents a number from1 to 15 preferably from 1 to 10, more preferably from 1 to 6,still more preferably from 1 to 3. In an embodiment according to the present invention, P consistsof q units of –(CHCHRO)- or –(CHRCHO)-, wherein q represents anumber within the range of 1 to 15 preferably 1 to 10, morepreferably from 1 to 6, still more preferably from 1 to 3 ; and nand m represents 0 and the sum of n+m+q represents a number from 1 to 12, preferably from 1 to 10, more preferably from 1 to 6, still more preferably from 1 to 3 .In another embodiment of the present invention, P consists of nunits of –(CHCHO)- and m units of –(CHCHRO)- or –(CHRCHO)-,wherein n and m represent independently an integer number from 0to 15 preferably 0 to 10, more preferably from 0 to 6, still morepreferably from 1 to 3; and q represents 0, and the sum of n+m+qrepresents a number from 1 to 15, preferably from 1 to 10, morepreferably from 1 to 6, still more preferably from 1 to 3 In one embodiment of the present invention the ether carboxylicacids or salts thereof of formula (I) comprise ethylene oxide andpropylene oxide groups. The ether carboxylic acid or salts thereofof formula (I) comprising ethylene oxide and propylene oxidegroups in separate blocks, and the ether carboxylic acid accordingto formula (I)comprising ethylene oxide and propylene oxide groupsrandomly distributed can be used in the compositions according to the invention. In a preferred embodiment of the present invention the ethercarboxylic acids or salts thereof of formula (I) comprisesethylene oxide and propylene oxide groups. The ether carboxylicacids of formula (I) comprising ethylene oxide and propylene oxidegroups in separate blocks can be used in the compositionsaccording to the invention. In a particular preferred embodiment, in the ether carboxylicacids or salts thereof represented by formula (I) are free ofbutylene oxide groups, i.e., p=0.In a particular preferred embodiment, the ether carboxylic acidsor salts thereof of formula (I) are free from propylene oxide andbutylene oxide, i.e. they only contains ethylene oxide units (m=0and p=0).In a more preferred embodiment, the ether carboxylic acids orsalts thereof are those of formula (Ia): R-O-(CHCHO)-CH- COOX(Ia) wherein R is a linear or branched alkyl or alkenyl chain having from 10to 18 carbon atoms; n is an integer number from 1 to 6; and X isH or a cation selected from the group consisting of an alkalimetal, an alkaline earth metal, ammonium and alkylammonium. In a preferred embodiment, R is a linear alkyl chain having from10 to 16 carbon atoms, and n is an integer number from 1 to 6.In a particular preferred embodiment, R is a linear alkyl chainhaving from 12 to 14 carbon atoms, and n is an integer number from 1 to 3. The skilled in the art knows how to obtain ether carboxylic acidsof Formula (I) and (Ia) according to the invention. Said ethercarboxylic acids are usually obtained by a process comprising thealkoxylation of an alcohol and subsequent carboxymethylation ofthe mixture of alkoxylated fatty alcohols and non-alkoxylatedfatty alcohols from carboxymethylation, as described by Meijerand Smid in Polyether Carboxylates; Anionic Surfactants; Surfactant Science Series, Vol. 56 (p. 313-361), edited by Helmut W. Stache, ISBN: 0-8247-9394-3. Examples of commercially available ether carboxylates of Formula (I) are AKYPO LF 1, AKYPO LF 2, AKYPO LF 4, and AKYPO LF 6, AKYPO RLM 25, AKYPO RLM 45, AKYPO RLM 100, AKYPO RO 10 VG, AKYPO RO 20 VG, AKYPO RO 50 VG and AKYPO RO 90 VG, all marketedby Kao Chemicals Europe. Among them, AKYPO RLM 25, AKYPO RLM 45,AKYPO RLM 100, AKYPO RO 10 VG, AKYPO RO 20 VG, AKYPO RO 50 VG,and AKYPO RO 90 VG, all marketed by Kao Chemicals Europe arepreferred. In a particular embodiment, the amount of ether carboxylic acid of formula (I), i.e. component (a), in the collector compositionof the invention is from 0.05-99.5 wt% based on the total weightof the composition, preferably from 3 to 60 wt%, more preferablyfrom 5 to 50 wt%.Each of the indicated amounts being expressed as percentage by weight of the mentioned component with respect to the total weight of the composition.Fatty acid (b)The collector composition according to the present inventionfurther comprises a component (b), said component being a fattyacid or mixture of fatty acids. In the context of the presentinvention, the fatty acid or mixture of fatty acids have formula(II): wherein R is a linear or branched alkyl or alkenyl chain havingfrom 3 to 29 carbon atoms and from 1 to 3 double bounds, preferablyfrom 7 to 25 carbon atoms, more preferably from 11 to 21 carbonatoms, still more preferably from 11 to 17 carbon atoms.Suitable C-C fatty acids or mixtures thereof are those obtained from vegetable and animal oils and fats such those obtained fromcastor oil, coconut oil, corn oil, mustard oil, olive oil, palmoil, peanut oil, rapeseed oil, sunflower oil, soybean oil, tall oil, tallow, eventually totally or partially hydrogenated, as well as purified or synthetic fatty acids, like caproic acid, caprylic acid, capric acid, isotridecanoic acid, lauric acid, myristic acid, palmitic acid, palmoleic acid, stearic acid, isostearic acid, 2- ethylhexanoic acid, oleic acid, elaidinic acid, petroselenic acid, linoleic acid, linolenic acid, eleostearic acid, ricinoleic acid, arachidic acid, gadoleic acid, behenic acid, erucic acid, or theirmixtures. Among them, tall oil, oleic acid or their mixtures arepreferred. In another embodiment of the present invention, component (b) ispreferably a C-C fatty acid or a mixture of C-C fatty acids;more preferably a C -C fatty acid or a mixture of C -C fattyIn a preferred embodiment according to the present invention,component (b) is a C -C fatty acid or a mixture ofacids, preferably obtained from tall oil fatty acid, oleic acidor their mixtures. In a particular preferred embodiment, component (b) is a C12-C18fatty acid or mixture of fatty acids, preferably oleic acid.In one embodiment according to the present invention the weightratio between component (a) and component (b), i.e. a:b , is 1:99to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50. In another embodiment according the present invention theweight ratio between component (a) and component (b), i.e. a:b ,is from is from 35:65 to 15:85 and / or from 33:67 to 25:75.In a particular embodiment, the amount of fatty acid of Formula (II) or fatty acid mixtures, i.e. component (b), in the collectorcomposition of the invention is from 0.05 to 99.5 wt%, preferablyfrom 40 to 97 wt%, more preferably from 50 to 95 wt%.Each of the indicated amounts being expressed as percentage by weight of the mentioned component with respect to the total weight of the composition.Ether Carboxylic acid or salts thereof (c)In preferred embodiments, the collector composition according to the present invention further may comprises a component (c), which is an ether carboxylic acid or a salt thereof as defined below. In these preferred embodiments, R in the ether carboxylic acids or salts thereof of component (a) represents a linear or branched alkyl or alkenyl chain as previously defined, but having from 10to 30 carbon atoms, preferably from 10 to 22, more preferably from12 to 18, even more preferably from 12 to 16, still more preferablyfrom 12 to 14. In these preferred embodiments, P, X, n, m and q in the ether carboxylic acids or salts thereof of component (a) are as previously defined. Preferably, in these particular embodiments, n, m and q in the ether carboxylic acids or salts thereof of component (a) are each independently a number from 0 to 15, preferably from 0 to 10, more preferably from 0 to 6, and the sum of n+m+q is from 1 to 15, preferably from 1 to 10, more preferably from 1 to 6. Thus, the collector composition according to the present invention (wherein R in the ether carboxylic acids or salts thereof of component (a) represents a linear or branched alkyl or alkenylchain as previously defined, but having from 10 to 30 carbonatoms, preferably from 10 to 22, more preferably from 12 to 18,even more preferably from 12 to 16, still more preferably from 12to 14) may further comprise a component (c), said component beingether carboxylic acids or salts thereof of formula (III):R-O-A-CH-COOX (III)wherein, R is a linear or branched alkyl or alkenyl chain havingfrom 4 to 8 carbon atoms; preferably from 6 to 8 carbon atoms,more preferably 8 carbon atoms;A consists of r units of –(CHCHO)-, and / or s units of –(CHCHRO)-or –(CHRCHO)-, and / or p units of –(CHCHRO)- or –(CHRCHO)-,wherein r represents a number within the range of 0 to 20,preferably from 0 to 18, more preferably from 0 to 8; s representsa number within the range of 0 to 20, preferably from 0 to 18,more preferably from 0 to 8; and p represents a number within therange of 0 to 20, preferably from 0 to 18, more preferably from 0to 8 and the sum of r+s+p represents a number from 1 to 20,preferably from 1 to 18, more preferably from 1 to 8;R represents a –CH group; and R represents a –CHCH group; andX is H or a cation selected from the group of an alkali metal, an alkaline earth metal, ammonium, an alkylammonium;with the proviso that component a) and component c) are different.As used herein, the term “alkyl” refers to a straight or branchedhydrocarbon chain containing the indicated number of carbon atoms,such as from 4 to 8 carbon atoms.As used herein, the term “alkenyl” refers to a linear hydrocarbonchain containing the indicated number of carbon atoms, such asfrom 4 to 8 carbon atoms, and from 1 to 3 double bonds.In the context of the present invention, the term “alkali metal” refers to any of lithium (Li), sodium (Na), potassium (K),rubidium (Rb) and cesium (Cs), preferably any of sodium andpotassium. In the context of the present invention, the term “alkaline earth metal” refers to any of beryllium (Be), magnesium (Mg), calcium(Ca), strontium (Sr) and barium (Ba), preferably any of magnesiumand calcium. In the context of the present invention, the term “ammonium” refers to NH . In the context of the present invention, the term “alkyl ammonium”refers to a quaternary ammonium substituted by 1, 2 or 3 alkylgroups as defined herein. In particular, each alkyl group has from 1 to 30 carbon atoms. Examples of alkylammonium aredimethyloctylammonium, dimethyldecylammonium, dimethyllauryl-ammonium, dimethylmyristylammonium, dimethylpalmitylammonium,dimethylcetylammonium, dimethylstearylammonium, dimethylbehenyl-ammonium, or mixtures thereof. Other suitable alkylammonium aremethyldioctylammonium, methyldidecylammonium, methyldilauryl-ammonium, methyldimyristylammonium, methyldipalmitylammonium,methyldicetylammonium, methyldistearylammonium, methyldibehenyl- ammonium, or mixtures thereof. As used herein, the term “salt” refers to the carboxylate anion of the compound of formula (III) as defined herein (i.e. R-O-A- CHCOO) and a suitable cation selected from the groups of an alkali metal (such as Na and K), an alkaline earth metal (such as Ca and Mg , ammonium, or alkylammonium. In a preferred embodiment of the present invention, salts of ether carboxylicacid represented by formula (III) are sodium salt or potassiumsalt of the ether carboxylic acid of the compound of formula (III),i.e. wherein X is Na or K. In another embodiment of the present invention, R is a linear or branched alkyl or a linear alkenyl derived from natural fats and oils, as well as of synthetic origin. Preferred fats and oils include palm oil, coconut oil, sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil; animal fat such as tallow, bone oil, fish oil, hardened oils and semi-hardened oils thereof, and mixtures thereof. As a result of its natural origin, the fats and oils may contain a great variety of alkyl and / or alkenyl groups, said groups being linear or branched, saturated or unsaturated. In a particular embodiment of the invention, R is a linear orbranched alkyl chain having from 4 to 8 carbon atoms, preferablyfrom 6 to 8 carbon atoms, more preferably 8 carbon atomsIn another particular embodiment of the invention, R is a linearalkyl chain having from 4 to 8 carbon atoms, preferably from 6 to8 carbon atoms, more preferably 8carbon atoms.In one embodiment of the present invention the ether carboxylicacid or salts thereof according to Formula (III) can beethoxylated and / or propoxylated and / or butoxylated, i.e. A is anethoxy and / or propoxy and / or butoxy group. The order of thesequence of ethylene oxide and / or propylene oxide and / or ethyleneoxide groups are not critical for the invention. Therefore, boththe ether carboxylic acids or salts thereof according to formula(III) containing ethylene oxide groups and / or propylene oxidegroups and / or butylene oxide groups in separate blocks and thoseether carboxylic acids or salts thereof according to formula (III)comprising ethylene oxide and / or propylene oxide and / or butyleneoxide groups are randomly distributed can be used in thecompositions according to the invention. In an embodiment according to the present invention, A consistsof r units of –(CHCHO)-, and / or s units of –(CHCHRO)- or –(CHRCHO)-, and / or p units of –(CHCHRO)- or –(CHRCHO)-, whereinr represents a number within the range of 0 to 20, preferably 0to 18, more preferably from 0 to 8; s represents a number withinthe range of 0 to 20, preferably 0 to 18, more preferably from 0to 8; p represents a number within the range of 0 to 20, preferably0 to 18, more preferably from 0 to 8. When r is 0, there are noethylene oxide units in the ether carboxylic acids or salt thereofof formula (III). When s is 0, there are no propylene oxide unitsin the ether carboxylic acids or salt thereof of formula (III).When p is 0, there are no butylene oxide units in the ethercarboxylic acids or salt thereof of formula (III). In the ethercarboxylic acids or salt thereof of formula (I) there is at leastone alkylene oxide unit which is an ethylene oxide, propylene oxide or butylene oxide. The alkoxylation degree is represented by the sum of moles of ethylene oxide and / or propylene oxide and / or butylene oxide that are present in the ether carboxylic acidsor salt thereof of formula (III), i.e., the sum of r+s+p, andwhich is each independently a number is from 1 to 20, preferablyfrom 1 to 18, more preferably from 1 to 8.As explained above, in the present invention the ether carboxylicacid of formula or salts thereof according to Formula (III) areethoxylated and / or propoxylated and / or butoxylated, i.e. A is anethoxy and / or propoxy and / or butoxy group. The order of thesequence of ethylene oxide and / or propylene oxide and / or ethyleneoxide groups are not critical for the invention. Therefore, boththe ether carboxylic acids or salts thereof and the sum of r+s+prepresents the average alkoxylation degree which corresponds to anumber from 1 to 20, preferably from 1 to 18, more preferably from1 to 8. In one embodiment of the present invention the ether carboxylicacids or salts thereof of formula (III) can be ethoxylated and / orpropoxylated and / or butoxylated. Both the ether carboxylic acidaccording to formula (III) comprising ethylene oxide groups and / orpropylene oxide groups and / or butylene oxide groups in separateblocks and the ether carboxylic acid according to formula (III)comprising ethylene oxide and / or propylene oxide and / or butyleneoxide groups randomly distributed can be used in the compositionsaccording to the invention..In an embodiment according to the present invention, A consistsof r units of –(CHCHO)- wherein s represents a number within therange of 1 to 20, preferably 1 to 18, more preferably from 1 to8; s and p represent 0, and the sum of r+s+q represents a numberfrom 1 to 20, preferably from 1 to 18, more preferably from 1 to 8.In an embodiment according to the present invention, A consistsof s units of –(CHCHRO)- or –(CHRCHO)- wherein s represents anumber within the range of 1 to 20, preferably 1 to 18, morepreferably from 1 to 8; and r and p represents 0, and the sum ofr+s+p represents a number from 1 to 20, preferably from 1 to 18,more preferably from 1 to 8.In an embodiment according to the present invention, A consistsof p units of –(CHCHRO)- or –(CHRCHO)-, wherein p represents anumber within the range of 1 to 20, preferably 1 to 18, morepreferably from 1 to 8; and r and s represents 0, and the sum ofr+s+p represents a number from 1 to 20, preferably from 1 to 18,more preferably from 1 to 8.In another embodiment of the present invention, A consists of runits of –(CHCHO)- and an average of s units of –(CHCHRO)- or–(CHRCHO)-, wherein r represents a number within the range of 0to 20, preferably 0 to 18, more preferably from 0 to 8; srepresents a number within the range of 0 to 20, preferably 0 to18, more preferably from 0 to 8; p represents 0, and the sum ofr+s+p represents a number from 1 to 20, preferably from 1 to 18,more preferably from 1 to 8. In one embodiment of the present invention the ether carboxylic acid or salts thereof of formula (III) comprises ethylene oxideand propylene oxide groups. The ether carboxylic acid of formula(III) comprising ethylene oxide and propylene oxide groups inseparate blocks, and the ether carboxylic acid according toformula (III)comprising ethylene oxide and propylene oxide groupsrandomly distributed can be used in the compositions according tothe invention. In a preferred embodiment of the present invention the ethercarboxylic acid of formula (III) comprises ethylene oxide andpropylene oxide groups. The ether carboxylic acid of formula (III)comprising ethylene oxide and propylene oxide groups in separateblocks can be used in the compositions according to the invention. In a particular preferred embodiment, in the ether carboxylic acidrepresented by formula (III) are free of butylene oxide, i.e. p=0.In a particular embodiment, the ether carboxylic acid or saltsthereof of formula (III) is free from propylene oxide and butyleneoxide, i.e. it only contains ethylene oxide units. In a more preferred embodiment, the ether carboxylic acid or saltsthereof are those of formula (IIIa):R-O-(CHCHO)-CH-COOX (IIIa) wherein R is a linear or branched alkyl or alkenyl chain having from 4to 8 carbon atoms; r is an integer number from 1 to 8, and X is Hor a cation selected from the group consisting of an alkali metal,an alkaline earth metal, ammonium and alkylammonium.In a particular preferred embodiment, R is a linear alkyl chainhaving from 6 to 8 carbon atoms and r is an integer number from 1to 6.The process for obtaining the ether carboxylic acids or saltsthereof according to Formula (III) is the same as previouslydescribed for obtaining the of compound of Formula (I).Examples of commercially available ether carboxylates of Formula(III) are AKYPO LF 1, AKYPO LF 2, AKYPO LF 4, and AKYPO LF 6,all marketed by Kao Chemicals Europe. In one embodiment according to the present invention the weightratio between component a) and component c) is from 99:1 to 1:99,preferably from 99:1 to 25:75, more preferably from 99:1 to 30:70In another embodiment according to the present invention theweight ratio between the sum of components a) and c), to componentb), that is ((a+c):(b)), is from 1:99 to 99:1, preferably from3:97 to 60:40, more preferably from 5:95 to 50:50.In a one embodiment according to the present invention the weightratio between the sum of components a) and c), to component b),that is ((a+c):(b)), is from 10:90 to 40:60.In another embodiment, according to the present invention theweight ratio between the sum of components a) and c), to componentb), that is ((a+c):(b)), is 35:65 to 15:85 and / or from 33:67 to25:75.In a particular embodiment, the amount of ether carboxylic acidof formula (III) in the collector composition of the invention isfrom 0.05 to 50wt% based on the total weight of the composition,preferably from 0.05 to 30 wt% based on the total weight of thecomposition, more preferably from 0.05 to 20 wt% based on thetotal weight of the composition. Each of the indicated amounts being expressed as percentage by weight of the mentioned component with respect to the total weight of the composition. Fatty alcohol (d)The collector composition according to the present invention mayfurther comprise a component (d), said component being a fattyalcohol or a mixture of fatty alcohols containing from 4 to 30 carbon atoms. C4-C30 fatty alcohols are aliphatic alcohols that can be derived from natural fats and oils. Preferred fats and oils include palm oil, coconut oil, sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil; animal fat such as tallow, fish oil, hardened oils and semihardened oils thereof, and mixtures thereof. As a result of their natural origin, the alcohols that are alkoxylated may contain a great variety of alkyl and alkenyl groups, said groups being linear or branched, saturated or unsaturated.Optionally, C4-C30 fatty alcohols are ethoxylated and / orpropoxylated, having and average alkoxylation degree from 1 to 25. In an embodiment according to the present invention, the fattyalcohol (d) or mixtures thereof is represented by formula (IV)and / or formula (IVa) or mixtures thereof:R-O-D-H (IV) R-O-E-H (IVa)wherein R, and R are as defined above for component (a) offormula (I) and component (c) of Formula (III), respectively.D consists of t units of –(CHCHO)-, and / or u units of –(CHCHRO)-or –(CHRCHO)-, and / or v units of –(CHCHRO)- or –(CHRCHO)-,wherein t represents a number within the range of 0 to 15, urepresents a number within the range of 0 to 15, v represents anumber within the range of 0 to 15, and the sum of t+u+v representsa number from 0 to 15 andE consists of x units of –(CHCHO)-, and / or y units of –(CHCHRO)-or –(CHRCHO)-, and / or z units of –(CHCHRO)- or –(CHRCHO)-;wherein x represents a number within the range of 0 to 20,preferably from 0 to 18, more preferably from 0 to 8; y representsa number within the range of 0 to 20; preferably from 0 to 18,more preferably from 0 to 8; and z represents a number within therange of 0 to 20, preferably from 0 to 18, more preferably from 0to 8; and the sum of x+y+z represents a number from 0 to 20,preferably from 0 to 18, more preferably from 0 to 10.Suitable fatty alcohols according to Formula (IV) and / or (IVa)are n-butanol, n-hexanol, n-octanol, 2-ethylbutanol, 2- methylpentanol, 2-ethylhexanol, 2-methylheptanol, n-decanol, 2- methyl-4-nonanol, 3,7-dimethyl-3-octanol, 3,7-dimethyl-1- octanol, 3,6-dimethyl-3-octanol, lauryl alcohol (1-dodecanol), myristyl alcohol (1-tetradecanol), cetyl alcohol (1-hexadecanol), palmitoleyl alcohol (cis-9-hexadecan-1-ol), stearyl alcohol (1- octadecanol), isostearyl alcohol (16-methylheptadecan-1-ol), elaidyl alcohol (9E-octadecen-1-ol), oleyl alcohol (cis-9- octadecen-1-ol), linoleyl alcohol (9Z, 12Z-octadecadien-1-ol), elaidolinoleyl alcohol (9E, 12E-octadecadien-1-ol), linolenyl alcohol (9Z, 12Z, 15Z-octadecatrien-1-ol), elaidolinolenyl alcohol (9E, 12E, 15-E-octadecatrien-1-ol), ricinoleyl alcohol (12-hydroxy-9-octadecen-1-ol), arachidyl alcohol (1-eicosanol), behenyl alcohol (1-docosanol), erucyl alcohol (cis-13-docosen-1- ol) or mixtures thereof. In another embodiment of the present invention, fatty alcohols (d) are derived from natural fats and oils, as well as of synthetic origin. Preferred fats and oils include palm oil, coconut oil, sunflower oil, rapeseed oil, castor oil, olive oil, soybean oil; animal fat such as tallow, bone oil, fish oil, hardened oils and semihardened oils thereof, and mixtures thereof. As a result of its natural origin, the fats and oils may contain a great variety of alkyl and / or alkenyl groups, said groups being linear or branched, saturated or unsaturated.In an embodiment of the present invention, the fatty alcohol (d)is represented by formula (IV):R-O-D-H (IV)wherein R and D are as previously defined.The fatty alcohol of formula (IV) can be ethoxylated and / orpropoxylated and / or butoxylated or non-alkoxylated. As explainedwith respect to compound of formula (I), ethylene oxide units,propylene oxide units and butylene oxide units can be present inseparate blocks or randomly distributed. In an embodiment of the present invention, R is a linear orbranched alkyl group containing 4 to 30 carbon atoms or a linearalkenyl group containing 4 to 30 carbon atoms and from 1 to 3double bounds.In another embodiment according to the present invention, R is alinear or branched alkyl group containing 10 to 30 carbon atomsor a linear alkenyl group containing 10 to 30 carbon atoms andfrom 1 to 3 double bonds, preferably from 10 to 22 carbon atoms,more preferably from 12 to 18 carbon atoms, still more preferably from 12 to 16 carbon atoms, even more preferably from 12 to 14 carbon atoms.In an embodiment according to the present invention, D consistsof t units of –(CHCHO)-, and / or u units of –(CHCHRO)- or –(CHRCHO)-, and / or v units of –(CHCHRO)- or –(CHRCHO)-, whereint represents a number within the range of 0 to 15 preferably 0 to10, more preferably from 0 to 6, even more preferably from 0 to3.; u represents a number within the range of 0 to 15, preferably0 to 10, more preferably from 0 to 6, even more preferably from 0to 3; v represents a number within the range of 0 to 15, preferably0 to 10, more preferably from 0 to 6,even more preferably from 0 to 3.The compound of formula (IV) can be non-alkoxylated (i.e. t=u=v=0)or alkoxylated. The alkoxylation degree of the fatty alcohol offormula (IV) is represented by the sum of t+u+v, eachindependently a number from 1 to 15, preferably from 1 to 10, morepreferably from 1 to 6, even more preferably from 1 to 3.In one embodiment of the present invention, the fatty alcohol offormula (IV) comprises ethylene oxide and propylene oxide groups.The fatty alcohol (IV) comprising ethylene oxide and propyleneoxide groups in separate blocks, and the fatty alcohol offormula(IV) comprising ethylene oxide and propylene oxide groupsrandomly distributed can be used in the compositions according to the invention.In a preferred embodiment of the present invention, the fattyalcohol of formula (IV) can be ethoxylated and propoxylated. Thefatty alcohol of formula (IV) comprising ethylene oxide andpropylene oxide groups in separate blocks can be used in thecompositions according to the invention. In a particular preferred embodiment of the present invention,the fatty alcohol of formula (IV) can be ethoxylated (i.e. u andv are 0).In one embodiment according to the present invention, component(d) of formula (IV) corresponds to the non-alkoxylated fattyalcohols those of formula (IV) (i.e. t, u, v are all 0) from thepreparation of ether carboxylic acid (a) of Formula (I).In one embodiment according to the present invention, component(d) of formula (IV) corresponds to a mixture of alkoxylated andnon-alcoxylated fatty alcohols of general form (IV) species fromthe preparation of the ether carboxylic acid (a) of Formula (I).In another embodiment of the present invention, component (d) comprising one or more fatty alcohols of Formula (IV) is intentionally added to the composition as a blend or mixture.In another embodiment of the present invention, the fatty alcoholis represented by formula (IVa):R-O-E-H (Iva)wherein R and D are as previously defined.The fatty alcohol of formula (IVa) can be ethoxylated and / orpropoxylated and / or butoxylated or non-alkoxylated. As explainedwith respect to compound of formula (IVa), ethylene oxide units,propylene oxide units and butylene oxide units can be present inseparate blocks or randomly distributed. In an embodiment of the present invention, R is a linear orbranched alkyl group containing 4 to 8 carbon atoms or a linearalkenyl group containing 4 to 8 carbon atoms and from 1 to 3double bounds; preferably from 6 to 8 carbon atoms, morepreferably 8 carbon atoms.In an embodiment according to the present invention, E consistsof x units of –(CHCHO)-, and / or y units of –(CHCHRO)- or –(CHRCHO)-, and / or z units of –(CHCHRO)- or –(CHRCHO)-, whereinx represents a number within the range of 0 to 20, preferably from0 to 18, more preferably from 0 to 8; y represents a number withinthe range of 0 to 20, preferably from 0 to 18, more preferablyfrom 0 to 8; z represents a number within the range of 0 to 20,preferably from 0 to 18, more preferably from 0 to 8. The alkoxylation degree of the fatty alcohol of formula (Iva) isrepresented by the sum of x+y+z are each independently a numberfrom 0 to 20, preferably from 0 to 18, more preferably from 0 to8. In one embodiment of the present invention, the fatty alcohol offormula (IVa) comprises ethylene oxide and propylene oxide groups.The fatty alcohol (IVa) comprising ethylene oxide and propyleneoxide groups in separate blocks, and the fatty alcohol of formula(IVa) comprising ethylene oxide and propylene oxide groupsrandomly distributed can be used in the compositions according to the invention.In a preferred embodiment of the present invention, the fattyalcohol of formula (IV) can be ethoxylated and propoxylated. Thefatty alcohol of formula (IV) comprising ethylene oxide andpropylene oxide groups in separate blocks can be used in thecompositions according to the invention.In a particular preferred embodiment of the present invention,the fatty alcohol of formula (IV) can be ethoxylated (i.e. whereiny and z are 0).In one embodiment according to the present invention, component(c) of formula (IVa) corresponds to the non-alkoxylated fattyalcohols of formula (IVa) (i.e. wherein x, y, z are 0), which maybe obtained as side products from the process for preparation ofether carboxylic acid (c) of Formula (III).In one embodiment according to the present invention, component(c) of formula (IVa) corresponds to the mixture of alkoxylatedfatty alcohols and non-alkoxylated fatty alcohols of formula (Iva)which may be obtained as side products from the carboxymethylationpreparation of the ether carboxylic acid (c) of Formula (III).In another embodiment of the present invention, component (d) comprising one or more fatty alcohols of Formula (IVa) is intentionally added to the composition as a blend or mixture.Alkoxylated fatty alcohols according to formulas (IV) and (IVa)may be produced by procedures well-known in the art by reacting the appropriate starting fatty alcohol with ethylene oxide and / orpropylene oxide and / or butylene oxide, in the presence of asuitable catalyst, e.g. a conventional basic catalyst, such as KOH, or so-called, narrow range catalyst (see e.g. Nonionic Surfactants: Organic Chemistry in Surfactant Science Series volume 72, 1998, pp 1-37 and 87-107, edited by Nico M. van Os; MarcelDekker, Inc). If propylene oxide, ethylene oxide and / or butyleneoxide are used, the alkoxides may be added as blocks in either order, or may be added randomly. In another embodiment of the present invention, the fatty alcohol(d) comprises a mixture of a fatty alcohol of formula (IV) andfatty alcohol of formula (IVa) as defined above. In another embodiment of the present invention, the fatty alcohol of formula (IV) and / or formula (IVa) comprises the correspondingnon-alkoxylated fatty alcohols to those of formula (IV) and / orformula (IVa) (i.e. wherein t, u, v, x, y and z are all 0).In another embodiment according to the present invention, component (d) corresponds to a mixture of alkoxylated fatty alcohols and non-alkoxylated fatty alcohols of formula (IV) and (IVa).In one embodiment of the present invention, component (d) ofFormula (IV) and (IVa) are intentionally added to the compositionas a blend or mixture.In one embodiment according to the present invention, the weightratio between component (a) and component (d), i.e. a:d ,is from99.99:0.001 to 1:50, preferably from 99.99:0.001 to 25:25, morepreferably from 99.99:0 to 50:10. In one embodiment according to the present invention, the weightratio between component (c) and component (d), i.e. c:d ,is from99.99:0.001 to 99.99:50, preferably from 99.99:0.001 to 25:25,more preferably from 99.99:0.001 to 50:10.The amount of fatty alcohol (d) in the collector composition of the invention is not more than 50 wt% based on the total weightof the composition, preferably from 0, to 25 wt%, more preferablyfrom 0 to 10 wt% based on the total weight of the composition.Each of the indicated amounts being expressed as percentage by weight of the mentioned component with respect to the total weight of the composition.Fatty acid ester (e)The collector composition of the present invention may further comprise a component (e), said component being fatty acid ester or mixture of fatty acid esters, wherein the fatty acid ester is having the formula (V): R-COO-R (V) wherein Ris selected from the group consisting of R-O-P-CH-, whereinR and P are as defined in Formula (I), R-O-A-CH-, wherein R andA are as defined in formula (III), and R which is as defined informula (II); Ris selected from the group consisting of -D-R, wherein R andD are as defined above for component (d) of formula (IV), and -E-R, wherein R and E are as defined above for component (d) offormula (IVa). In another embodiment according to the present invention, R is R-O-P- wherein R and P are as defined in Formula (I).In another embodiment according to the present invention, R is a R-O-A-; wherein R and A are as defined in formula (III).In another embodiment according to the present invention, R is R- as defined above in component (b) in Formula (II).In another embodiment according to the present invention, R is -D-R, wherein R and D are as defined above for component (d) offormula (IV). In another embodiment according to the present invention, R is -E-R, wherein R and E are as defined above for component (d) offormula (IVa). In one embodiment according to the present invention, the fatty acid moieties in the component (e) are derived from the same fatty component (b).In one embodiment according to the present invention, component (e) present in the composition is intentionally added.In an embodiment of the present invention, the component (e) maybe obtained as a by-product from the reaction of the ethercarboxylic acid (a) of formula (I) and the free fatty alcohol (d)of formula (IV) present in the composition. According to thepresent embodiment component (d) of formula (V), R represents R-O-P-CH-, wherein R and P are as defined in Formula (I); andR is-D-R, wherein R and D are as defined above for component (d) offormula (IV). The fatty acid ester according to the present embodiment is represented by general formula (V-I): R-O-P-CH-COO-D-R (V-I)wherein R,P and D are as previously defined.In an embodiment of the present invention, the component (e) offormula (V-I) may be obtained as a by-product from the reactionof the ether carboxylic acid (a) of formula (I) and the free fattyalcohol (d) of formula (IV), wherein component (d) of formula (IV)corresponds to the non-alkoxylated fatty alcohols those of formula(IV) (i.e. t, u, v are all 0) from the preparation of ethercarboxylic acid (a) of Formula (I).In an embodiment of the present invention, the component (e) fattyacid ester or a mixture of fatty acid esters of formula (V-I) maybe obtained as a by-product from the reaction of the ethercarboxylic acid (a) of formula (I) and the free fatty alcohol (d)of formula (IV) , wherein component (d) of formula (IV)corresponds to a mixture of alkoxylated and non-alkoxylated fatty alcohols of general form (IV) species from the preparation of the ether carboxylic acid (a) of Formula (I).In an embodiment of the present invention, the component (e) fattyacid ester or a mixture of fatty acid esters may be obtained as aby-product from the reaction of the ether carboxylic acid (a) offormula (I) and the free fatty alcohol (d) of formula (IVa) presentin the composition. According to the present embodiment component(d) of formula (V), R represents R-O-P-CH-, wherein R and P are as defined in Formula (I) andR is -E-R, wherein R and E are as defined above for component(d) of formula (IVa). The fatty acid ester or a mixture of fattyacid esters (e) according to the present embodiment is representedby general formula (V-II): R-O-P-CH-COO-E-R (V-II)wherein R, R, P and E are as previously defined.In an embodiment of the present invention, the component (e) thefatty acid ester or a mixture of fatty acid esters of formula (V-II) may be obtained as a by-product from the reaction of the ethercarboxylic acid (a) of formula (I) and the free fatty alcohol (d)of formula (IVa), wherein component (d) of formula (IVa)corresponds to the non-alkoxylated fatty alcohols those of formula(IVa) (i.e. x, y, z are all 0) from the preparation of ethercarboxylic acid (a) of Formula (I). In an embodiment of the present invention, the component (e) thefatty acid ester or a mixture of fatty acid esters of formula (V-II) may be obtained as a by-product from the reaction of the ethercarboxylic acid (a) of formula (I) and the free fatty alcohol (d)of formula (IVa), wherein component (d) of formula (IVa) corresponds to a mixture of alkoxylated and non-alkoxylated fattyalcohols of general formula (IVa) species from the preparation ofthe ether carboxylic acid (a) of Formula (I). In an embodiment of the present invention, the fatty acid esteror mixture of fatty acid esters (e) may be obtained as a by-product from the reaction of the ether carboxylic acid (c) offormula (III) and the free fatty alcohol (d) of formula (IV).According to the present embodiment component (d) of formula (V), R represents R-O-A-CH-, wherein R and A are as defined in Formula (III) andR is -D-R, wherein R and D are as defined above for component(d) of formula (IV). The fatty acid ester or a mixture of fattyacid esters (e) according to the present embodiment is representedby general formula (V-III): R-O-A-CH-COO-D-R (V-III)wherein R, R, A and D are as previously defined.In an embodiment of the present invention, the fatty acid esteror a mixture of fatty acid esters(e) of formula (V-III) may beobtained as a by-product from the reaction of the ether carboxylicacid (c) of formula (III) and the free fatty alcohol (d) of formula(IV), wherein component (d) of formula (IV) corresponds to thenon-alkoxylated fatty alcohols those of formula (IV) (i.e. t, u,v are all 0) from the preparation of ether carboxylic acid (a) ofFormula (I). In an embodiment of the present invention, the fatty acid esteror mixture of fatty acid esters(e) of formula (V-III) may beobtained as a by-product from the reaction of the ether carboxylicacid (c) of formula (III) and the free fatty alcohol (d) of formula(IV), wherein component (d) of formula (IV) corresponds to amixture of alkoxylated and non-alkoxylated fatty alcohols ofgeneral form (IV) species from the preparation of the ether carboxylic acid (a) of Formula (I). In an embodiment of the present invention, the fatty acid esteror mixture of fatty acid esters (e) may be obtained as a by-product from the reaction of the ether carboxylic acid (c) offormula (III) and the free fatty alcohol (d) of formula (IVa).According to the present embodiment component (d) of formula (V), R represents R-O-A-CH-, wherein R and A are as defined inFormula (III) and R is -E-R, wherein R and E are as definedabove for component (d) of formula (IVa). The fatty acid ester ora mixture of fatty acid esters (e) according to the presentembodiment is represented by general formula (V-IV): R-O-A-CH-COO-E-R (V-IV) wherein R, A and E are as previously defined. In an embodiment of the present invention, the fatty acid esteror a mixture of fatty acid esters (e)of formula (V-IV) may beobtained as a by-product from the reaction of the ether carboxylicacid (c) of formula (III) and the free fatty alcohol (d) of formula(IVa), wherein component (d) of formula (IVa) corresponds to thenon-alkoxylated fatty alcohols those of formula (IVa) (i.e. x, y,z are all 0) from the preparation of ether carboxylic acid (c) ofFormula (III). In an embodiment of the present invention, the fatty acid esteror a mixture of fatty acid esters(e) of formula (V-IV) may beobtained as a by-product from the reaction of the ether carboxylicacid (c) of formula (III) and the free fatty alcohol (d) of formula(IVa), wherein component (d) of formula (IV) corresponds to a mixture of alkoxylated and non-alkoxylated fatty alcohols ofgeneral form (IVa) species from the preparation of the ethercarboxylic acid (c) of Formula (III). In an embodiment of the present invention, the fatty acid esteror a mixture of fatty acid esters (e) may be obtained by thereaction of Fatty acid or mixture of fatty acids (b) of Formula(II) and the free fatty alcohol (d) of formula (IV). According tothe present embodiment component (d) of formula (V), R representsR as defined in Formula (II) and R is -D-R, wherein R and D areas defined above for component (d) of formula (IV). The fatty acidester or a mixture of fatty acid esters according to the presentembodiment is represented by general formula (V-V): R COO-D-R (V-V)wherein R, R and D are as previously defined.In an embodiment of the present invention, the acid ester (d) offormula (V-V) is obtained by the reaction of the fatty acid (b)of formula (II) and the fatty alcohol (d) of Formula (IV), whereincomponent (d) of formula (IV) corresponds to non-alkoxylated fatty alcohols of general form (IV) species from the preparation of the ether carboxylic acid (a) of Formula (I). In an embodiment of the present invention, the fatty acid esteror a mixture of fatty acid esters(e) of formula (V-V) may beobtained from the reaction of fatty acid or mixture of fatty acids(b) of formula (II) and the free fatty alcohol (d) of formula(IV), wherein component (d) of formula (IV) corresponds to a mixture of alkoxylated and non-alkoxylated fatty alcohols ofgeneral form (IV) species present in the reaction mixture fromthe preparation of the ether carboxylic acid (a) of Formula (I). In an embodiment of the present invention, the fatty acid esteror mixture of fatty acid esters (e) is obtained by the reactionfrom the fatty acid or mixture of fatty acids (b) of formula (II)and the of formula (III) and the free fatty alcohol(d) of formula(IVa). According to the present embodiment component (d) offormula (V), R represents R-, wherein R is as defined in Formula (II) andR is -E-R, wherein R and E are as defined above for component(d) of formula (IVa). The fatty acid ester or a mixture of fattyacid esters (e) according to the present embodiment is representedby general formula (V-VI): R-COO-E-R (V-VI)wherein R, R and E are as previously defined.In an embodiment of the present invention, the fatty acid esteror mixture of fatty acids ester (d) of formula (V-VI) is obtainedby the reaction of the fatty acid or mixture of fatty acids(b) offormula (II) and the fatty alcohol (d) of Formula (IVa), wherein component (d) of formula (IVa) corresponds to non-alkoxylated fatty alcohols of general form (IVa) species from the preparation of the ether carboxylic acid (c) of Formula (III). In an embodiment of the present invention, the fatty acid ester(e) of formula (V-VI) may be obtained from the reaction of fattyacid or mixture of fatty acids (b) of formula (II) and the freefatty alcohol (d) of formula (IVa), wherein component (d) offormula (IV) corresponds to a mixture of alkoxylated and non- alkoxylated fatty alcohols of general form (IVa) species present in the reaction mixture from the preparation of the ether carboxylic acid (c) of Formula (III).In an embodiment of the present invention, the amount of the fattyacid ester (e) is from 0% wt to 50% wt; preferably from 0% wt to25% wt; more preferably from 0% wt to 10% wt, based on the totalweight of the composition. Each of the indicated amounts being expressed as percentage by weight of the mentioned component with respect to the total weight of the composition. Collector composition of the invention In an embodiment, the present invention is directed to the use of the collector composition for the beneficiation of lithium-containing minerals contained in an ore comprising lithium-containing minerals and gangue minerals, wherein the compositioncomprises:(a) at least an ether carboxylic acid or salts thereof of Formula(I) as described above, and (b) a fatty acid or mixture of fatty acids according to Formula (II) as described above; characterized in that the weight ratio between component a) and component b) is comprised between 99:1 and 1:99, preferably between 3:97 and 60:40, more preferably between 5:95 and 50:50. In another embodiment according to the present invention theweight ratio between component (a) and component (b), i.e. a:b,is from is from 35:65 to 15:85 and / or from 33:67 to 25:75.Other components of the collector composition used in the invention are at least an ether carboxylic acid or salts thereof(c), fatty alcohols (d), fatty acid esters or mixture of fattyacid esters (e) as previously defined, and / or water.In a particular embodiment, the collector composition comprisescomponent (a), component (b), component (c). It is surprisinglyfound that the addition of second ether carboxylic acid (c) havea synergistic effect between both components which significantlyimprove LiO purity.A particular embodiment according to the present invention, isdirected to the use of the collector composition for the beneficiation of lithium-containing minerals contained in an ore, such as lithium silicates, preferably spodumene.In a particular embodiment, the collector composition used in theinvention comprises an ether carboxylic acid or salts thereof offormula (I) (component(a)) and a fatty acid or mixtures of fattyacids of Formula (II)(component (b)). In a particular embodiment,the amount of ether carboxylic acids or salts thereof of formula(I) in the composition used in the invention is at last 99.5wt%,preferably from 3 to 60wt%, more preferably from 5 to 50 wt%; andthe amount of fatty acids or mixtures of fatty acids in thecollector composition used in the invention is at last 99.5%,preferably from 40 to 97 wt%, more preferably from 50 to 95 wt%.The amount of ether carboxylic acid or salts thereof representedby formula (I) and the amount of a fatty acid (b), are selectedso that a total amount of 100 wt% is not exceeded. Preferably,the weight ratio between ether carboxylic acid or salts thereof(a) of formula (I) and fatty acid (b) of Formula (II), i.e. a:b,from 1:99 to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50. In another particular embodiment, the collector composition usedin the invention comprises one or more ether carboxylic acid orsalts thereof of Formula (I) (component (a)), a fatty acid ormixture thereof of Formula (II) (component (b)), and at least anether carboxylic acid or salts thereof of Formula (III) (component(c)),. Preferably, the weight content of the sum of (a) and (c)in the collector composition of the invention is not greater than95 wt% the indicated amount being expressed as percentage perweight with respect to the total weight of the compositionpreferably from 3 to 60 wt%, more preferably from 5 to 50 wt%,content of fatty acid (b) is between 0.05 to 99.5 wt%, preferablybetween 40 to 97 wt%, more preferably between 50 to 95 wt% basedon the total weight of the composition.In another embodiment according to the invention, the weight ratiobetween the ether carboxylic acid or salts thereof (a) of formula(I) and the ethercarboxylic acid or salts thereof (c) of formula(III), with respect to the fatty acid (b) of formula (II), i.e.(a+c):b, is from 1:99 to 99:1, preferably from 3:97 to 60:40, morepreferably from 5:95 to 50:50. In a particular preferredembodiment weight ratio (a+c):b is from 35:65 to 15:85, more preferred from 33:67 to 25:75. In another particular embodiment, the collector composition usedin the invention comprises at least the ether carboxylic acid offormula (I) (component (a)), the fatty acid of formula (II)(component (b)) and the fatty alcohol of formula (IV)(component(d)) wherein component (d) corresponds to thealkoxylated fatty alcohol and non-alkoxylated fatty alcohol fromthe preparation of the ether carboxylic acid (a), wherein saidcomponents are as previously defined. In one embodiment accordingto the use of the present composition, the weight content of theether carboxylic acids of formula (I) in the collector compositionused in the invention is not greater than 99.5 wt%; the weightcontent of the fatty acid (b) is from 0.05 to 99.5 wt% and theweight content of fatty alcohol (d) in the collector compositionis from 0.05 to 50 wt%, wherein the weight percentages are basedon the total weight of the composition. Preferably the weightcontent of ether carboxylic acids of formula (I) in the collectorcomposition used in the invention is from 3 to 60 wt%; the weightcontent of fatty acid (b) is from 40 to 97 wt% and the weightcontent of fatty alcohol (d) in the collector composition is from0.05 to 25 wt%, wherein the weight percentages are based on thetotal weight of the composition. Preferably, the weight ratiobetween ether carboxylic acid or salts thereof (a) of formula (I)and the fatty alcohol (d) formula (III), i.e a:d, is from 99:1 to1:50, preferably from 99:1 to 25:25, more preferably from 99:1 to50:10. In another particular embodiment, the collector composition usedin the invention comprises at least the ether carboxylic acid orsalts thereof of formula (I) (component (a)), the fatty acid ormixtures thereof of formula (II) (component (b)) and the fattyacid ester or a mixture of fatty acid esters of formula (V)(component (e)), wherein said components are as previouslydefined. Preferably, the weight content of the at least the ethercarboxylic acid or salts thereof of formula (I) in the collector composition is not greater than 99.5 wt%; the weightcontent of fatty acid (b) is from 0.05 to 99.5 wt% and the weightcontent of fatty acid ester (e) is from 0% wt to 50% wt; preferablyfrom 0 wt% to 25 wt%; more preferably from 0 wt% to 10 wt%, whereinthe weight percentages are based on the total weight of thecomposition. In another particular embodiment, the collector composition usedin the invention comprises at least the ethercarboxylic acid orsalts thereof of formula (I) (component (a)), the fatty acid ormixture of fatty acids of formula (II) (component (b)), at leastthe ether carboxylic acid or salts thereof of formula (III)(component (c)) and the fatty acid ester or a mixture of fattyacid esters of formula (V)(e), as previously defined, wherecomponent (a) and (c) are different the sum of the weight contentof the ether carboxylic acids or salts thereof of formula (I) andformula (III) the indicated amount being expressed as percentageper weight with respect to the total weight of collectorcomposition, the sum of weight of (a) and (c) in the collectorcomposition is not greater than 99.5%wt based on the total weight of the composition; wherein the weight content of the fatty acid or mixture of fatty acids in the collector is from 0.05 to 99.5wt% and wherein the weight content of fatty acid ester (e) in thecollector composition is from 0 wt% to 50 wt%; preferably from 0wt% to 25 wt%; more preferably from 0 wt% to 10 wt%, wherein theweight percentages are based on the total weight of thecomposition. Preferably, the weight ratio between the at least one ether carboxylic acid or salts thereof of formula (I) and thefatty or mixture of fatty acids, i.e. a:b, is from 1:99 to 99:1,preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50.More preferably, the weight ratio between the sum of the at leastone ether carboxylic acids or salts thereof (a) and component (c)with respect to the fatty acids or mixture of fatty acids (b), that is ((a)+(c)):(b), is from 1:99 to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50. In another particular embodiment, the collector composition usedin the invention comprises one or more ethercarboxylic acid orsalts thereof of formula (I) (component (a)), the fatty acid ormixture of fatty acids of formula (II) (component (b)), the fattyalcohol of formula (IV)(component (d)), wherein said components are as previously defined an wherein component(d) corresponds toa mixture of the non-carboxymethylated species (alkoxylated fattyalcohol and / or non-alkoxylated fatty alcohol) from the preparationof the ether carboxylic acid (a) and a fatty acid ester of formula(V)(e), wherein the weight content of the ether carboxylic acidsor salts thereof of formula (I) in the collector composition is not greater than 99.5%wt; wherein the weight content of fatty acid or mixture of fatty acids in the collector is from 0.05 to 99.5wt%; wherein the weight content of fatty alcohol (d) in thecollector composition is not more than 50 wt%, preferably from 1 to 25 wt%, more preferably from 1 to 10 wt% and wherein the weightcontent of fatty acid ester (e) in the collector composition isfrom 0 wt% to 50 wt%, preferably from 0 wt% to 25 wt%; morepreferably from 0 wt% to 10 wt%, wherein the weight percentagesare based on the total weight of the composition. Preferably, theweight ratio between at least the ether carboxylic acid or saltsthereof of formula (I) and the fatty or mixture of fatty acids,i.e. a:b, is from is from 1:99 to 99:1, preferably from 3:97 to60:40, more preferably from 5:95 to 50:50. The weight ratiobetween the at least the ether carboxylic acid or salts thereof(a) and the fatty alcohol (d), that is a:d, is from 99:0.001 to0.001:50, preferably from 99:0.001 to 25:25, more preferably from99:0.001 to 50:10.In another particular embodiment, the collector composition usedin the invention comprises one or more ethercarboxylic acid orsalts thereof of formula (I) (component (a)), the fatty acid ormixture of fatty acids of formula (II) (component (b)), at leastthe ether carboxylic acid or salts thereof of formula (III)(component (c)) and component (d), wherein component (d)corresponds to the mixture of the non-carboxymethylated species(alkoxylated fatty alcohol and / or non-alkoxylated fatty alcohol)from the preparation of the ether carboxylic acid (a) and (c),according to Form (IV) and (Iva) respectively. with the provisothat component (a) and component (c) are different, wherein sumof the weight content of the ether carboxylic acids or saltsthereof of formula (I) and component (c) of Formula (III) in thecollector composition is not greater than 99.5 wt%; wherein theweight content of the fatty acid or mixture of fatty acids in thecollector is at least 99.5 wt%, and wherein the weight content ofthe fatty alcohol (d) in the collector composition is from in thecollector composition is from 0 to 50 wt%, preferably from 1 to25 wt%, more preferably from 1 to 10 wt% wherein the weightpercentages are based on the total weight of the composition.Preferably, the weight ratio between the at least one ether carboxylic acid or salts thereof of formula (I) and a fatty ormixture of fatty acids , i.e. a:b, is from is from 1:99 to 99:1,preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50.More preferably, the weight ratio between the sum of the at leastone ether carboxylic acids or salts thereof(a) and component (c)with respect to the fatty acids or mixture of fatty acids (b),that is ((a)+(c)):(b), is from 1:99 to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50. In another embodiment according to the present invention, the weight ratio between the sum of the at least one ether carboxylicacids or salts thereof(a) and component (c) with respect to thefatty alcohols (d), wherein fatty alcohol is a mixture of fattyalcohols as previously defined, that is ((a)+(c)):(d), is from99:0.001 to 0.001:50, preferably from 99:0.001 to 25:25, morepreferably from 99:0.001 to 50:10.In another particular embodiment, the collector composition used in the invention comprises at least the ethercarboxylic acid orsalts thereof of formula (I) (component (a)), the fatty acid ormixture of fatty acids of formula (II) (component (b)), at leastthe ether carboxylic acid or salts thereof of formula (III)(component (c)), a mixture of fatty alcohol of formula (IV) and(IVa)(component (d)), wherein component (d) corresponds to themixture of the non-carboxymethylated species (alkoxylated fattyalcohol and non-alkoxylated fatty alcohol) from the preparationof the ether carboxylic acid (a) and (c), and the fatty acid esteror mixture of fatty acid esters of formula (V)(component (e),wherein all said components are as previously defined, with the proviso that component (a) and component (c) are different, andwherein the sum of the weight content of the ether carboxylicacids or salts thereof of formula (I) and the component of Formula(III) together in the collector composition is not greater than99.5wt%; wherein the weight content of the fatty acid or mixture of fatty acids in the collector is at least 99.5wt%; wherein theweight content of fatty alcohol (d) in the collector compositionis not more than 50 wt%, preferably from 1 to 25 wt%, morepreferably from 1 to 10 wt%, and wherein the weight content offatty acid ester(e) in the collector composition is from 0 wt% to50 wt%, preferably from 0 wt% to 25 wt%, more preferably from 0wt% to 10 wt%, wherein the weight percentages are based on thetotal weight of the composition. Preferably, the weight ratiobetween the at least one ether carboxylic acid or salts thereofof formula (I) and the fatty or mixture of fatty acids, i.e. a:b,is from is from 1:99 to 99:1, preferably from 3:97 to 60:40, morepreferably from 5:95 to 50:50. More preferably, the weight ratiobetween the sum of the at least one ether carboxylic acids orsalts thereof(a) and component (c) with respect to the fatty acidsor mixture of fatty acids (b), that is ((a)+(c)):(b), is from 1:99 to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95to 50:50, and the weight ratio between the at least one ethercarboxylic acid or salts thereof (a) and the fatty alcohol (d),that is a:d, is from 99:0.001 to 0.001:50, preferably from99:0.001 to 25:25, more preferably from 99:0.001 to 50:10.The collector compositions of the invention can additionally contain one or more of the following additives, this list not limiting and other components may also be present: non-ionic surfactants, anionic surfactants and cationic surfactants,foaming agents, foam controllers, pH regulators, activators forthe mineral to be obtained in the foam (i.e. CaCl) or deactivatorsfor the unwanted minerals in the foam, dispersants, etc. PROCESS TO OBTAIN THE COLLECTOR COMPOSITION Another aspect of the present invention is related to a process for producing a collector composition comprising a component (a) comprising at least one ether carboxylic acids or salts thereof of formula (I) and component (b) comprising a fatty acid or mixtureof fatty acids by mixing component (a) with component (b),preferably under constant stirring, in particular from 10 minutesto 1 hour (preferably for 10 to 20 min, more preferably for 15min), more preferably at a temperature between 20ºC to 25 ºC.In another embodiment according to the present invention, the collector composition obtained with this process may further comprise component (c) comprising at least an ether carboxylic acids or salts thereof represented by formula (III) as previouslydefined, with the proviso that component (a) and (c) are different.In one embodiment of the present invention, the collectorcomposition used in the invention is obtained by mixing component(a), component (b) and component (d) of formula (IV), whereincomponent (d) is as previously defined and preferably correspondsto the non-carboxymethylated species (alkoxylated fatty alcoholand / or non-alkoxylated fatty alcohol) from the preparation of theether carboxylic acid (a). Preferably, the components are mixed,preferably under constant stirring, in particular from 10 minutes to 1 hour (preferably for during 10 to 20 min, more preferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. In one embodiment of the present invention, the collectorcomposition used in the invention is obtained by mixing component(a), component (b) and component (e). Preferably, the componentsare mixed, preferably under constant stirring, in particular from10 minutes to 1 hour (preferably for during 10 to 20 min, more preferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. In another particular embodiment, the collector composition usedin the invention is obtained by mixing the at least anethercarboxylic acid or salts thereof of formula (I) (component(a)), a fatty acid or mixture of fatty acids of formula (II)(component (b)), the fatty alcohol of formula (IV)(component (d)),wherein component(d) corresponds to a mixture of the non-carboxymethylated species (alkoxylated fatty alcohol and / or non-alkoxylated fatty alcohol) from the preparation of the ethercarboxylic acid (a), and the fatty acid ester (component e)..Preferably, the components are mixed, preferably under constantstirring, in particular from 10 minutes to 1 hour (preferably for during 10 to 20 min, more preferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. In another particular embodiment, the collector composition usedin the invention is obtained by mixing the at least anethercarboxylic acid or salts thereof of formula (I) (component(a)), the fatty acid or mixture of fatty acids of formula (II)(component (b)), the fatty alcohol of formula (IV) (component(d)), wherein component(d) corresponds to a mixture of the non-carboxymethylated species (alkoxylated fatty alcohol and / or non-alkoxylated fatty alcohol) from the preparation of the ethercarboxylic acid (a), and the fatty acid ester (component e).Preferably, the components are mixed, preferably under constantstirring, in particular from 10 minutes to 1 hour (preferably for during 10 to 20 min, more preferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. In another particular embodiment, the collector composition usedin the invention is obtained by mixing the ethercarboxylic acidor salts thereof of formula (I) (component (a)), the a fatty acidor mixture of fatty acids of formula (II) (component (b)), the atleast an ether carboxylic acid or salts thereof of formula (III)(component (c)), the fatty alcohol (d), wherein component (d)corresponds to a mixture of the non-carboxymethylated species(alkoxylated fatty alcohol and / or non-alkoxylated fatty alcohol)according to formulas (IV and Iva) from the preparation of theether carboxylic acid (a) and (c). Preferably, the components aremixed, preferably under constant stirring, in particular from 10minutes to 1 hour (preferably for during 10 to 20 min, morepreferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. In another particular embodiment, the collector composition usedin the invention is obtained by mixing the at least anethercarboxylic acid or salts thereof of formula (I) (component(a)), the fatty acid or mixture of fatty acids of formula (II)(component (b)), the at least an ether carboxylic acid or saltsthereof of formula (III) (component (c)) and the fatty acid estercomponent (e)). Preferably, the components are mixed, preferablyunder constant stirring, in particular from 10 minutes to 1 hour (preferably for during 10 to 20 min, more preferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. In another particular embodiment, the collector composition usedin the invention in obtained by mixing the at least anethercarboxylic acid or salts thereof of formula (I) (component(a)), the fatty acid or mixture of fatty acids of formula (II)(component (b)), the at least an ether carboxylic acid or saltsthereof of formula (III) (component (c)), the fatty alcohol offormula (d) (IV and Iva), wherein component (d) corresponds to amixture of the non-carboxymethylated species (alkoxylated fattyalcohol and / or non-alkoxylated fatty alcohol) from the preparationof the ether carboxylic acid (a) and (c), and a fatty acid esterof formula (V)(component e), according to formulas V-VI to V-VIII). Preferably, the components are mixed, preferably underconstant stirring, in particular from 10 minutes to 1 hour (preferably for during 10 to 20 min, more preferably for 15 min), more preferably at a temperature between 20ºC to 25 ºC. Process of flotation Another object of the invention is the process for the beneficiation of lithium-containing minerals from an ore,comprising lithium-containing minerals and gangue minerals,wherein collector compositions as previously defined are used.In a particular embodiment the lithium-containing minerals arelithium silicates, preferably but not limited to spodumene.The present invention relates a process for the beneficiation oflithium-containing minerals, such as lithium silicates, from orecomprising lithium-containing minerals and gangue minerals,wherein the process comprises the steps of:a) mixing the ore comprising lithium-containing minerals andgangue minerals with water to obtain an aqueous mixture,b) adding the collector composition as previously described tothe aqueous mixture obtained in step a),c) agitating the mixture obtained in step b) (conditioningstep) d) introducing air injection to the mixture c to generate afroth, and e) collecting the lithium-containing minerals, such as lithiumsilicates, in the froth.In a particular embodiment, the process comprises additionaloptional steps b) and / or c), so that the process comprises the following steps: a1) mixing the ore comprising lithium-containing mineralsand gangue minerals with water to obtain an aqueous mixture,b1) optionally adjusting the pH of the aqueous mixtureobtained in step a) to obtain a pH adjusted aqueous mixture,c1) optionally, conditioning the ore with a depressantand / or activator, d1) adding the collector composition as previouslydescribed to the aqueous mixture obtained in step a1) (whensteps b1) and c1) are not carried out, to the aqueous mixture obtained in step b1) (when step b1) is carried out but step c1) is not carried out) or to the aqueous mixture obtained in step c1) (when step c1) is carried out), e1) agitating the mixture obtained in step d1)(conditioningstep) f1) introducing air injection to generate a froth, andg1) collecting the lithium-containing minerals, such aslithium silicates, from the froth.Step a) and a1) is mixing the ore comprising lithium-containingminerals and gangue minerals, with water to form an aqueousmixture. Preferably the lithium-containing mineral is spodumene(LiAlSiO). The main constituents of the ore comprising lithium-containing minerals are as previously defined, in particular, spodumene, quartz, plagioclase, feldspars, muscovite and other silicate minerals. In one embodiment according to the present invention, during step b1) the pH is adjusted with a pH regulating substance such as NaOH, NaCO, KOH, KCO, HCl, HSO, HPO or HNO. In one embodiment according to the present invention, during step b1) the adjusted pH is in a pH range between 6 and 10; preferably from 7 and 9. If the pH of the suspension obtained in step a) and / or a1) is already within the required value, step b1) does not need to be carried out. Step c1) is optional and is conditioning the ore with a depressant and / or activator.The term “depressant” refers to reagents that inhibit theflotation of unwanted minerals, allowing the selective recoveryof lithium-containing minerals. In lithium flotation, depressantsare used to suppress the flotation of minerals such as quartz or feldspar, which can interfere with the separation process. Sodium silicate is a commonly used depressant in lithium flotation to suppress the flotation of quartz and other silicate minerals. The term “activator” refers to chemical compounds usually added to promote the interaction of collector molecules with the mineralsurfaces. Examples are NaCO, NaOH, NaS, CaOH, CaCO and CaCl,among them CaCl is preferred. The next step, step b and d1) is adding the collector composition as previously described to the aqueous suspension obtained in stepa), in step a1), in step b1) or in step c1). The collectorcomposition is added to the aqueous suspension obtained in stepa) or a1) when steps b1) and c1) are not carried out. The collectorcomposition is added to the aqueous mixture obtained in step b1)when step b1) is carried out and step c1) is not carried out. Thecollector composition is added to the aqueous mixture obtained instep c1) when step c1) is carried out. In one embodiment according to the present invention, component(a) and component (b) of the collector composition are charged asa blend in step b) and d1) or alternatively component (a) andcomponent (b) of collector composition are charged separately.In another embodiment according to the present invention, component (a), component (b) and component (c) of the collectorcomposition are charged as a blend in step b) and d1) oralternatively component (a), component (b) and component (c) of collector composition are charged separately. In another embodiment according to the present invention, component (a), component (b) and component (d), wherein component(d) corresponds to a mixture of the non-carboxymethylated species(alkoxylated fatty alcohol and non-alkoxylated fatty alcohol) fromthe preparation of the ether carboxylic acid (a) are charged as ablend in step b) and d1) or alternatively component (a), component(b) and component (d) of collector composition are charged separately. In another embodiment according to the present invention,component (a), component (b) and component (e) are charged as ablend in step b) and d1) or alternatively component (a), component(b) and component (e) of collector composition are chargedseparately. In another embodiment according to the present invention,component (a), component (b), component (d) and component (e),wherein component (d) corresponds to a mixture of the non-carboxymethylated species (alkoxylated fatty alcohol and non-alkoxylated fatty alcohol) from the preparation of the ethercarboxylic acid (a), are charged as a blend in step b) and d1) oralternatively component (a), component (b), component (d) andcomponent (e) of collector composition are charged separately.In another embodiment according to the present invention,component (a), component (b), component (c) and component (d),wherein component (d) corresponds to a mixture of the non-carboxymethylated species (alkoxylated fatty alcohol and non-alkoxylated fatty alcohol) from the preparation of the ethercarboxylic acid (a), are charged as a blend in step b) and d1) oralternatively component (a), component (b), component (c) and component (e) of collector composition are charged separately. In another embodiment according to the present invention,component (a), component (b), component (c) and component (e),are charged as a blend in step b) and d1) or alternativelycomponent (a), component (b), component (c), component (d) and component (e) of collector composition are charged separately. In another embodiment according to the present invention,component (a), component (b), component (c), component (d) andcomponent (e), wherein component (d) corresponds to a mixture ofthe non-carboxymethylated species (alkoxylated fatty alcohol andnon-alkoxylated fatty alcohol) from the preparation of the ethercarboxylic acid (a), are charged as a blend in step b) and d1) or alternatively component (a), component (b), component (c), component (d) and component (e) of collector composition are charged separately.In another embodiment, the flotation process comprise the step ofadding one or more modifiers before step b) or d1).The term “modifier” refers to reagents that are used to modify the action of the collector on mineral surfaces so that the interaction between mineral and collector is modified. In some cases, by promoting the interaction, in other cases by notallowing it. Examples of modifiers are sodium silicate, sodiummetaphosphate, polyhydric organic acids, starch, sodiumfluorosilicate, quebracho and tannin. Step d) and f1) is agitating the mixture obtained in step d) withair injection to generate a froth. This can be done by injectionof air into the aqueous mixture in the form of bubbles.Step e) and g1) is collecting the lithium silicates in the froth.This can be done in flotation cells. The flotation process can be undertaken in one cycle, or alternatively in several cycles to maximize the recovery of the lithium concentrate.In a particular preferred embodiment according to the presentinvention, to maximize the recovery of the desired lithiumcontaining minerals, such as lithium silicates, particularlyspodumene, the flotation process could further include a secondcycle comprising the steps of:i) mixing the floated mineral obtained during step e) or g1) withwater to form a aqueous mixture,ii) agitating the aqueous suspension obtained in step i) underair injection to generate a froth, andiii) collecting the lithium-containing minerals in the froth.In one embodiment according to the present invention process offlotation is a one cycle process, according to steps a) to e) ora1) to g1) as previously defined, for high LiO recovery.In another embodiment, process of flotation is performed in twocycles including steps from a) to e) and i) to iii) or a1) to g1)and i) to iii) aiming at high purities.In another preferred embodiment, the amount of collectorcomposition which is added in step b) and d1) is in the range of5 to 5000 g per ton of ore provided in step a) or a1), preferablyfrom 10 to 3000 g per ton of ore, more preferably from 40 to 2000g per ton of ore. The following examples are given in order to provide a person skilled in the art with a sufficiently clear and completeexplanation of the present invention, but should not be consideredas limiting of the essential aspects of its subject, as set out in the preceding portions of the description. EXAMPLES The first part of the Examples section refers to the preparation of the collector compositions of the invention. The second part of the Examples section refers to the flotation tests of the collector compositions and the determination of % ofmass recovery (yield) and the LiO content (%) in the flotationconcentrate. Example 1. Preparation of collector compositionsPreparation of collector composition 1 (according to theinvention):33 g of polyoxyethylene C12-14 ether carboxylic acid having anaverage of 3 ethylene oxide units (component a)) and 67 g oleicfatty acid (component b)) are mixed during 10 minutes at 25 ºC.Preparation of collector composition 2 (according to theinvention):16.5 g C12-14 alkyl ether carboxylic acid (component a)) havingan average ethoxylation degree of 3 ethylene oxide units, 67 g ofoleic fatty acid (component b)) and 16.5 g of C8 alkyl ethercarboxylic acid (component c)) having an average ethoxylationdegree of 5 are mixed during 10 minutes at 25 ºC. Example 2. Flotation tests and collectors evaluation Flotation tests An ore containing spodumene (LiAlSiO) as lithium containingmineral and other silicate minerals as gangue minerals was usedin all examples. The main constituents of this ore are: spodumene, quartz, plagioclase, feldspars, muscovite and other silicate minerals.The ore containing spodumene and other silicates (gangue minerals)has a content of 1.2% of LiO analyzed by ICP-OES.The particle size distribution of spodumene ore was characterizedat 22ºC by laser diffraction using a Malvern Mastersizer 2000 with2-propanol as solvent. The results are shown in Table 1:Particle size Distribution Size (µm)d(0.1) 25.5d(0.5) 115.4d(0.9) 345.0Table 1: Particle size distribution of spodumene ore d(0.1): Represents the 10% by volume of the particles with diameters smaller than this sized(0.5): Represents the 50% by volume of the particles withdiameters smaller than this sized(0.9): Represents the 90% by volume of the particles withdiameters smaller than this size The flotation of the spodumene (direct flotation) from an ore that contains silicate minerals was carried out to enrich the content of LiO. The spodumene is recovered in the froth concentrate. A Denver model D-12 laboratory flotation equipment was used. The tests were carried out in a 1.2 L flotation cell at 1000 rpm and at room temperature. It was used tap water with hardness rangebetween 10 – 20 ºHF.The tests consisted in 2 flotation steps, a rougher flotation and a cleaner flotation. In the rougher flotation, the mineral was conditioned for 5 minutes at pH 8 using NaOH as pH modifier. Afterwards, the collector composition was added at the desired dosage. The floatedore of the rougher flotation was used as feed material of thecleaner flotation. The floated ore of the cleaner flotation is the final concentrate ore. Target figures are LiO content as high as possible, preferably LiO content (%) > 5.5%.Collectors’ evaluationThe collector dosages were from 400 to 2000 g / ton added as such.The results of the flotation are shown in Table 1. The analyses of the % of LiO were obtained by means of ICP-OES. References 1-2 are examples according to the invention, whereas C1-C2 arecomparative references.Table 1.- Evaluation of the collectorscollector dosageCollector (400-2000ppm) Ether Carboxylic collector LiO Fatty Weight ratio % Examples acid Dosage content acid (b:a:c) Yield Alkyl Moles (ppm) (%) Chain EO C12- 13 Oleic 67 / 33 / 0 400 15.97 5.8C14 C12- 3 2 C14Oleic 67 / 16.5 / 16.5 600 14.38 6.3C8 5C12- C13 - 0 / 100 / 0 400 13.87 5.2C14C2 - Oleic 100 / 0 / 0 2000 14.57 5.1From above results it can be seen that examples of the invention show a good % yield and high LiO content (higher than 5.5%), whereas the comparative examples fail to comply with bothrequirements at the same time. The collector composition of theinvention (examples 1 and 2) allow less collector composition tobe used (collector dosage) to obtain the same % yield and higherLiO content compared to other collectors (comparative 1 and 2).

Claims

CLAIMS1. Use of a collector composition for the beneficiation oflithium-containing minerals from an ore comprising lithium-containing minerals and gangue minerals, wherein the collector composition comprises:a) at least an ether carboxylic acid or salts thereof of formula(I) R-O-P-CH-COOX (I) wherein, R is a linear or branched alkyl or alkenyl chain having from 4 to 30 carbon atoms;P consists of n units of –(CHCHO)-, and / or m units of –(CHCHRO)-or –(CHRCHO)-, and / or q units of –(CHCHRO)- or –(CHRCHO)-,wherein n represents a number within the range of 0 to 25, mrepresents a number within the range of 0 to 25, q represents anumber within the range of 0 to 25, and the sum of n+m+q represents a number from 1 to 25; R represents a –CH group and R represents a –CHCH group; andX is H or a cation selected from the group consisting of an alkalimetal, an alkaline earth metal, ammonium, and alkylammonium; andb)a fatty acid or mixtures of fatty acids.

2. Use according to claim 1, wherein component b) is a C4-C30fatty acid or a mixture of C4-C30 fatty acids, preferably a C8- C26 fatty acid or a mixture of C8-C26 fatty acids, more preferably a C12-C22 fatty acid or a mixture of C12-C22 fatty acids.

3. Use according to any one of claims 1 or 2, wherein the weightratio between component a) and component b) is from 1:99 to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50.

4. Use according to any one of claims 1 to 3, wherein R representsa linear or branched alkyl or alkenyl chain having from 10 to 30carbon atoms, preferably from 10 to 22, more preferably from 12 to 18.

5. Use according to any one of claims 1 to 4, wherein n, m and qare each independently a number from 0 to 15, preferably from 0 to 10, more preferably from 0 to 6, and the sum of n+m+q is from1 to 15, preferably from 1 to 10, more preferably from 1 to 6.

6. Use according to any one of claims 4 or 5, wherein the collectorcomposition further comprises:c) at least an ether carboxylic acid represented or salts thereofof formula (III)R-O-A-CH-COOX (III) wherein, R is a linear or branched alkyl or alkenyl chain having from 4to 8 carbon atoms; preferably from 6 to 8 carbon atoms, morepreferably 8 carbon atoms;A consists of r units of –(CHCHO)-, and / or s units of –(CHCHRO)-or –(CHRCHO)-, and / or p units of –(CHCHRO)- or –(CHRCHO)-;wherein r represents a number within the range of 0 to 20,preferably from 0 to 18, more preferably from 0 to 8; s representsa number within the range of 0 to 20; preferably from 0 to 18,more preferably from 0 to 8; and p represents a number within therange of 0 to 20, preferably from 0 to 18, more preferably from 0to 8; and the sum of r+s+p represents a number from 1 to 20,preferably from 1 to 18, more preferably from 1 to 10; R R and X are as defined in any of the preceding claims.

7. Use according to any one of claims 4 to 6, wherein the weightratio between component a) and component c) is from 99:1 to 1:99,preferably from 99:1 to 25:75, more preferably from 100:0 to50:50.

8. Use according to claim 6 or 7, wherein the weight ratio betweenthe sum of component a), component c), and component b), that is((a+c):(b)), is 1:99 to 99:1, preferably from 3:97 to 60:40, more preferably from 5:95 to 50:50.

9. Use according to any one of claims 4 to 8, wherein thecomposition further comprises a component (d), said component (d) comprising a fatty alcohol of formula (IV), a fatty alcohol of formula (IVa) or mixtures thereof: R-O-D-H (IV) R-O-E-H (IVa) whereinD consists of t units of –(CHCHO)-, and / or u units of –(CHCHRO)-or –(CHRCHO)-, and / or v units of –(CHCHRO)- or –(CHRCHO)-,wherein t represents a number within the range of 0 to 15,preferably from 0 to 10, more preferably from 0 to 6; u representsa number within the range of 0 to 15, preferably from 0 to 10,more preferably from 0 to 6; v represents a number within therange of 0 to 15, preferably from 0 to 10, more preferably from 0to 6; and the sum of t+u+v represents a number from 0 to 15,preferably from 0 to 10, more preferably from 0 to 6;E consists of x units of –(CHCHO)-, and / or y units of –(CHCHRO)-or –(CHRCHO)-, and / or z units of –(CHCHRO)- or –(CHRCHO)-;wherein x represents a number within the range of 0 to 20,preferably from 0 to 18, more preferably from 0 to 8; y representsa number within the range of 0 to 20; preferably from 0 to 18,more preferably from 0 to 8; and z represents a number within therange of 0 to 20, preferably from 0 to 18, more preferably from 0to 8; and the sum of x+y+z represents a number from 0 to 20,preferably from 0 to 18, more preferably from 0 to 10; andR, R, R and R are as defined in any of the preceding claims.

10. Use according to claim 9, wherein the weight ratio betweencomponent a) and component d) is from 99:1 to 1:50, preferablyfrom 99:1 to 25:25, more preferably from 99:1 to 50:10.

11. Use according to claim 9 or 10, wherein the weight ratiobetween component a), component b), and component d), that is((a+d):b), is from 1:99 to 99:1, preferably from 3:97 to 60:40,more preferably from 5:95 to 50:

50.

12. A process for producing a collector composition as defined in any one of claims 1 to 11, comprising mixing under stirringcomponent a) as defined in any one of claims 1, 4 or 5, componentb) as defined in claim 1 or 2, component c) as defined in claim 6, when present, and component d) as defined in claim 9, when present.

13. A process for the beneficiation of lithium-containing mineralsfrom an ore comprising lithium-containing minerals and gangueminerals, comprising:a) mixing the ore comprising lithium-containing minerals andgangue minerals with water to obtain an aqueous mixture,b) adding the collector composition according to the present invention to the aqueous mixture obtained in a), c) agitating the aqueous mixture obtained in b), d) introducing air injection to the mixture c) to generate a froth, ande) collecting the lithium-containing minerals in the froth.

14. The process according to claim 13, wherein from 5 to 5000 gof the collector composition according to any one of claims 1 to 11 is added in step b) per ton of ore of step a).

15. A collector composition for the beneficiation of lithium-containing minerals from an ore comprising lithium-containingminerals and gangue minerals, wherein the collector compositioncomprises:a) at least an ether carboxylic acid or salts thereof represented by formula (I) R-O-P-CH-COOX (I) wherein, R is a linear or branched alkyl or alkenyl chain having from 4 to 30 carbon atoms;P consists of n units of –(CHCHO)-, and / or m units of –(CHCHRO)- or –(CHRCHO)-, and / q units of –(CHCHRO)- or –(CHRCHO)-, wherein n represents a number within the range of 0to 25, m represents a number within the range of 0 to 25, and qrepresents a number within the range of 0 to 25, and the sum of n+m+q represents a number from 1 to 25; R represents a –CH group; and R represents a –CHCH group; andX is H or a cation selected from the group consisting of an alkalimetal, an alkaline earth metal, ammonium and alkylammonium,b) a fatty acid or mixtures of fatty acids;characterized in that the weight ratio between component a) andcomponent b) is comprised between 99:1 and 1:99.