EP1025908A1 - Biodegradable quaternary esters used as flotation agents - Google Patents

Abstract

The flotation process for removing mineral impurities, especially silicates, from ores comprises passing air through an aqueous suspension of the ground ore in the presence of a flotation aid and separating off the foam plus the impurities. The collector components used in the flotation aid comprise quaternised ester compounds (esterquats) of formula (I), (II) and/or (III), optionally with other anionic, cationic, amphoteric and/or non-ionic substances. In the formulae: R1CO, R5CO and R9CO = 6-24C acyl; R2, R3, R6 and R10 = H or 6-24C acyl; R4 = 1-4C alkyl or -(CH2CH2O)qH, where q = 1-12; R7, R8, R11, R12 and R13 = 1-4C alkyl; (m + n + p) or (m + n) = 0 or 1-12; and X = halide, alkylsulphate or alkylphosphate.

Description

Field of the Invention

The invention relates to so-called ester quats as an aid in the flotation of non-sulfidic Ores. The quaternized esterification products of the mono-, di- or Trialkanolamines with aliphatic carboxylic acids show good collector properties on the one hand, especially in silicate flotation, on the other hand excellent biodegradability both under aerobic and under anaerobic conditions.

State of the art

Flotation is a commonly used sorting process for mineral processing Raw materials in which the valuable minerals are separated from the worthless ones. Non-sulfidic minerals include, for example, apatite, calcite, fluorite, scheelite and other salt-like minerals, cassiterite, hematite, magnesite and other metal oxides, e.g. Oxides of titanium and zirconium as well as certain silicates and aluminosilicates.

For example, DE-A1 35 17 154 describes the use of surfactant mixtures as Aid for the flotation of non-sulfidic ores. Here are mixtures of add-on products of ethylene oxide and propylene oxide to a fatty alcohol having 8 to 22 carbon atoms and at least one anionic, cationic or ampholytic surfactant used. The use of quaternized ester compounds is not mentioned or suggested.

WO 94/26419 describes the flotation of silicate-containing calcite minerals. As a solution is the flotation in the presence of a quaternary ammonium compound and an alkylene oxide adduct to perform on an amino compound, the silicate accumulating in the foam. The use of quaternized ester compounds in such a flotation process is neither mentioned nor suggested.

DE-A1 41 06 866 discloses a process for the selective flotation of phosphorus minerals, being a collector of a mixture of salts of the half esters of alkyl substituted succinic acids and other anionic tenisides can be described.

DE-A1 also discloses a process for the selective flotation of phosphorus minerals 41 05 384. It is proposed here that the flotation slurry with carboxylic acids of chain length 6 to add up to 24 acylated protein or peptide hydrolyzates.

Calcite minerals are of great importance for the paper industry, for example. Calcite is an important filling material for the paper industry, with which the Have the whiteness and the transparency of the product regulated. Calcite minerals come often associated with silicates before, so that a separation for cleaning the calcite of the undesirable silicate required in many applications. This is usually the Flotation used. For example, calcite minerals can be quaternary Ammonium compounds mixed with fatty alcohols or non-polar hydrocarbons rid of annoying silicates. The sometimes very high need for as clean as possible fractional mineral components, and thus on flotation aids, usually leads to the fact that large amounts of waste water loaded with auxiliary agents have to be disposed of, and usually get into the environment. The previously used for silicate flotation quaternary ammonium compounds are characterized by high ecotoxicity and an extremely unfavorable degradation behavior, so that an accumulation in the environment and therefore long-term damage to sensitive ecosystems can be expected. Another disadvantage of the collectors described so far is that minerals with a high magnesium content could not be floated or only with great difficulty. Magnesium salts lead in connection with the conventional quaternary collectors Ammonium compounds to an extremely stable foam that has a high half-life (i.e. breaks only slowly) and thus at least the separation of the floated material greatly delayed. While foam that breaks too quickly through foamer usually easily set to the desired foam thickness and thus the desired half-life reducing the half-life is usually a major problem. The conventional addition of defoamers usually changes as a surface active Agens the interaction between collectors and minerals in such a way that elaborate Test series to achieve the desired balance half-life / separation result are necessary. The present invention seeks to remedy this.

The task was therefore to provide a biodegradable flotation aid To make available, on the one hand, a high selectivity, especially in the flotation of Silicates, on the other hand, it guarantees excellent biodegradability. In addition should this flotation aid be able to be successful even with such minerals to be used, which have a high proportion of magnesium.

Surprisingly, it has now been found that quaternized ester compounds, the so-called Esterquats, show a high silicate selectivity, easily biodegradable and with different Co-collectors can be combined and are optimal even with high magnesium contents Ensure foam strength and half-life.

Description of the invention

wobei R¹CO für einen Acylrest mit 6 bis 24 Kohlenstoffatomen, R² für R¹CO, R³, R⁴ und R⁵ unabhängig voneinander für Alkylreste mit 1 bis 4 Kohlenstoffatomen, m und n in Summe für 0 oder Zahlen von 1 bis 12 und X für Halogenid, Alkylsulfat oder Alkylphosphat steht, einzeln oder im Gemisch, gegebenenfalls zusammen mit weiteren anionischen, kationischen, amphoteren und/oder nichtionischen Substanzen als Sammlerkomponente einsetzt.The invention thus relates to a process for removing mineral impurities, in particular silicates, from ore mixtures by flotation, by mixing ground ore mixture with water to form a suspension, introducing air into the suspension in the presence of a flotation aid and the resulting foam together with those contained therein flotated impurities are separated, with the proviso that quaternized ester compounds (esterquats) of the general formula (I)

where R ¹ CO for an acyl radical with 6 to 24 carbon atoms, R ² for R ¹ CO, R ³ , R ⁴ and R ⁵ independently of one another for alkyl radicals with 1 to 4 carbon atoms, m and n in total for 0 or numbers from 1 to 12 and X stands for halide, alkyl sulfate or alkyl phosphate, individually or in a mixture, optionally together with other anionic, cationic, amphoteric and / or nonionic substances as collector component.

Either the esterquats according to the invention are referred to as collectors in the sense of the invention or such substances that are known to those skilled in the art on account of their effect as collectors are. Mixtures of one or more collectors and, where appropriate, further additives, which, for example, only because of their rheological effect Collectors can be added or otherwise handled or processed serving the collector are referred to below as flotation aids. they include therefore the collector mix and all other additives. However, this remains unaffected that collectors may also be the only constituent of such a flotation aid can be used insofar as this collector under the operating conditions is manageable and its use can be carried out as intended. This definition does not affect the individual components of the entire flotation aid can be metered separately into the flotation system.

Esterquats" werden im allgemeinen quaternierte Fettsäuretri-ethanol-aminestersalze verstanden. Es handelt sich dabei um bekannte Stoffe, die man nach den einschlägigen Methoden der präparativen organischen Chemie erhalten kann. In diesem Zusammenhang sei auf die Internationale Patentanmeldung WO 91/01295 (Henkel) verwiesen, nach der man Triethanolamin in Gegenwart von unterphosphoriger Säure mit Fettsäuren partiell verestert, Luft durchleitet und anschließend mit Dimethylsulfat oder Ethylenoxid quaterniert. Stellvertretend für den umfangreichen Stand der Technik sei an dieser Stelle auf die Druckschriften US 3,915,867, US 4,370,272, EP-A2 0 239 910, EP-A2 0 293 955 A2, EP-A2 0 295 739 und EP-A2 0 309 052 A2 verwiesen. Übersichten zu diesem Thema sind beispielsweise von O.Ponsati in C.R. CED-Kongress, Barcelona, 1992, S.167 , R.Puchta et al. in Tens.Surf.Det.,30, 186 (1993), M.Brock in Tens. Surf. Det. 30, 394 (1993) und R.Lagerman et al. in J.Am.Oil.Chem.Soc., 71, 97 (1994) erschienen.Under the label

Esterquats "are generally understood to be quaternized fatty acid triethanol amine ester salts. These are known substances which can be obtained by the relevant methods of preparative organic chemistry. In this connection, reference is made to the international patent application WO 91/01295 (Henkel) , after which triethanolamine is partially esterified with fatty acids in the presence of hypophosphorous acid, air is passed through and then quaternized with dimethyl sulfate or ethylene oxide. Representative of the extensive state of the art at this point is the documents US 3,915,867, US 4,370,272, EP-A2 0 239 910, EP-A2 0 293 955 A2, EP-A2 0 295 739 and EP-A2 0 309 052 A2.Overviews on this topic are, for example, from O.Ponsati in CR CED Congress, Barcelona, 1992, p.167, R.Puchta et al. In Tens.Surf.Det., 30 , 186 (1993), M.Brock in Tens. Surf. Det. 30 , 394 (1993) and R. Lagerman et al. In J.Am.Oil Chem. Soc., 71 , 97 (1994) e seemed.

The fatty acids and the triethanolamine can be used in a molar ratio of 1.1: 1 to 3: 1 to produce the quaternized esters. With regard to the application properties of the ester quats, an application ratio of 1.2: 1 to 2.2: 1, preferably 1.5: 1 to 1.9: 1, has proven to be particularly advantageous. The preferred ester quats are technical mixtures of mono-, di- and triesters with an average degree of esterification of 1.5 to 1.9, for example 1.64 and 1.9, and are derived from technical C _16/18 - tallow or Palm fatty acid (iodine number 0 to 40).

Floatable minerals can be divided into the two groups of polar and non-polar minerals divide, the surface of the non-polar minerals being difficult to hydrate, and such minerals must ultimately be called hydrophobic. Nonpolar minerals include graphite, sulfur, molybdenite, diamond, coal and Talk, all of which can be floated in their original state. The these minerals containing ores usually only require the addition of non-specific collectors, such as diesel oil, kerosene or similar hydrocarbons such as oxo oils, to the to support the natural hydrophobicity of the minerals.

Polar minerals, on the other hand, have strong covalent or ionic surface bonds, rapid hydration through water molecules in the form of multilayers are accessible. These minerals include, for example, malachite, azurite, chrysocolla, Wulfenite, cerrusite, witherite, magnesite, dolomite, smithsonite, rhodochrosite, siderite, magnetite, Monazite, hematite, goethite, chromite, pyrolusite, borax, wolframite, columbite, tantalite, rutile, Zircon, hemimorphite, beryl and garnet.

The sulfidic minerals are an exception group. Here are almost without exception Collectors are used, which are able to with those on the mineral surface React sulfide groups, such as xanthates, dithiophosphates, mercaptans, thionocarbamates or dithiolates, with the formation of nasal bubbles becoming the dominant one Flotation mechanism will.

The usual steps in the process are usually dry or preferably wet grinding of the minerals, the suspension of the rock powder thus obtained in Water with the addition of the flotation aid and, preferably after in one case the measured exposure time of the collectors contained in the flotation aid and, if applicable Co-collector, the blowing of air into the suspension to create the flotation foam.

The grain size distribution of the rock powder allows the flotation behavior of the individual mineral components to be controlled within a certain range. In the opposite sense, however, the particle size also influences the use of the collector, so that both grain size and, for example, collector concentration can be determined on site in a short series of tests. In general, however, it can be said that with increasing grain size, increasing hydrophobization of the grain must take place before flotation occurs.
As a rule, the ore should be ground so fine that the individual fine grains consist only of one type of mineral, either the valuable mineral or the impurities. The ideal grain size usually has to be determined depending on the respective mineral. In the present case, however, a grain size distribution of approximately 5 to 500 μm has generally been found to be practicable, although narrower distributions can be advantageous in individual cases. For example, ores rich in silicate can be separated by float with the results according to the invention with excellent results if less than 40, preferably less than 30 and particularly preferably less than 15% by weight of the total ore fraction have grain sizes of less than 250 μm. In the sense of an optimized design, it can be particularly preferred if the proportions of grain sizes above 125 μm are less than 15% by weight or preferably less than 10 or 6% by weight. The lower limit of the grain sizes is determined both by the possibility of mechanical comminution and by the manageability of the removed components. As a rule, more than 20% by weight of the rock powder should have a size smaller than about 50 μm, a proportion of particles of this diameter of more than 30 or 40% by weight being preferred. In the sense of the invention, it is particularly advantageous if more than 40% by weight of the ore particles have a diameter of less than 45 μm.

In certain cases it may be necessary and useful to mix the stone powder in two or more, for example three, four or five fractions of different particle diameters to divide and subject these fractions to the flotative separation. For the purpose of The flotation aids according to the invention can be used in the present invention only one, but in principle also for several or all required separation steps be used. The invention also encompasses the successive administration of several different ones Flotation aids, at least one, but possibly also several of the Flotation aids must be according to the invention. The fractions available in this way can after the flotation process can be combined or treated separately.

The technical parameters of the flotation plant in connection with a specific flotation aid and a particular ore can be the result of the flotation process in influence certain limits. So it can be an advantage, for example, that after a short flotation time to separate the resulting foam, since the content of flotated Contamination, or change on floating ore depending on the flotation time may, in this case a longer flotation period may lead to a worse one Result as a shorter. Likewise, it can happen in the reverse case that the separation process with increasing time to a higher purity or otherwise better Quality of the recyclable fraction leads. The optimization of such external parameters is the responsibility of Routine activities of the specialist who is familiar with the technical circumstances of the respective Flotation plant is familiar.

As a rule, such reagents are used for the flotation as the surface tension or modify the surface chemistry. They usually fall into the classes of Classify collectors, frothers, regulators, activators and pushers (deactivators).

Collectors are reagents that create a coating on the mineral surface and make them water-repellent, making them accessible for the attachment of air bubbles. Non-sulfidic minerals are usually floated with collectors such as fatty acids, amines, quaternary ammonium compounds, sulfonates and / or hydrocarbons. Known anionic collectors are, for example, saturated and unsaturated fatty acids, in particular tall oil fatty acids, oleic acid, alkyl sulfates, in particular alkyl sulfates, alkyl aryl sulfonates, alkyl sulfosuccinates, alkyl sulfosuccinamates and alkyl lactates derived from fatty alcohols and / or fatty alcohol mixtures.
Known cationic collectors are, for example, primary aliphatic amines, in particular the fatty amines derived from the fatty acids of vegetable and animal fats, as well as certain alkyl-substituted and hydroxyalkylene-substituted alkylenediamines and the water-soluble salts of these amines.

The esterquats are usually used either as the only collector component or as part of an active substance mixture composed of several collectors and co-collectors in an amount of 10 to 2000 g / t ore. For the purposes of the invention, preference is given to using esterquats of the general formula ( I ).

The ester quats usually come in the form of 50 to 90% by weight alcoholic solutions on the market, which can usually be easily diluted with water if necessary.

Quaternary ammonium compounds such as cetyltrimethylammonium bromide or distearyldimethylammonium chloride are not considered to be biodegradable according to the OECD guidelines, since no degradation takes place, especially under anaerobic conditions. In sewage treatment plants, they are mostly adsorbed on sludge and thus removed from further degradation. However, the esterquats meet all the requirements placed on a flotation aid with regard to biodegradability. For example, the esterquats are in Closed Bottle Test "(OECD Test No. 301 D) as readily biodegradible ",> 80% BOD / COD. Additional C ¹⁴ screening tests also confirm the complete degradation of the ester quats. In particular, the biodegradability under aerobic as well as under anaerobic conditions gives the ester quats an outstanding position among the quaternary nitrogen compounds.

The esterquats can be used alone or in a mixture with them in the sense of the invention further cationic, nonionic or, under certain conditions, even anionic Surfactants can be used as co-collectors.

It should be noted, of course, that the biodegradability of the collector and co-collector existing overall system by adding difficult or non-degradable co-collectors is deteriorating overall. Depending on the area of application and economic necessity the co-collectors can also be used in larger quantities than the ester quats, for example 80, 70 or 60% by weight. Usually, however, the co-collectors should they are not readily biodegradable themselves, only in minor amounts together can be used with the esterquats. As a rule, there should be a share whose upper limit about 50% by weight of the total collector system is not exceeded, whereas smaller proportions of 40, 30 or 20 wt .-% with respect to the biodegradability clear Can bring benefits. This corresponds to the collector / co-collector ratio of, for example about 0.95: 1, 1: 1, 1.1: 1, 1.2: 1, 1.3: 1 or 1.4 to 1 up to 2: 1, 3: 1, or 4: 1. Possibly it will even be that 10% or less by weight for adequate optimization the collection properties of the system used, so that 5, 3 or even proportions 2 and less wt .-% co-collector are sufficient. But overall, the addition the esterquats according to the invention as collectors the biodegradability of the overall system in any case improved.

The cationic surfactants that can be used as co-collectors include, in particular, the amino compounds such as the acid addition salts of the primary aliphatic amines as well alkylenediamines or hydroxyalkyl substituted with α-branched alkyl radicals Alkylene diamines. Furthermore, ether amines, ether diamines and fatty acid amido amines, as they are, for example, the condensates of polyamines with fatty acids. As primary aliphatic amines are particularly suitable for those of the fatty acids of native fat and Oils derived from fatty amines with 8 to 24 carbon atoms. Mixtures are usually found here of fatty amines, for example tallow amines or hydrotalgamines, such as those from the Tallow fatty acids or the hydrogenated tallow fatty acids via the corresponding nitriles and their Hydrogenation are accessible.

wobei R⁵, R⁶, R⁷ und R⁸ lineare und/oder verzweigte Alkyl- und/oder Alkenylreste mit 1 bis 24 C-Atomen darstellen,
in einem Mischungsverhältnis von 0,01:1 bis 100:1einzusetzen. Bevorzugt werden hierbei etwa Trimethylalkyl(talg)ammoniumchlorid (R⁵, R⁶ R⁷ = Methyl, R⁸ - C-Kettenverteilung der Talgfettsäuren) oder Dimethyldikokosalkylammoniumchlorid (R⁵ R⁶ = Methyl; R⁷ R⁸ = C-Kettenverteilung der Kokosfettsäuren) zugegeben. Es handelt sich hierbei um Gemische von Verbindungen der Formel (II), wie sie beim Aufarbeiten von Fettsäureschnitten wie beispielsweise Talgfettsäure oder Kokosfettsäure mit nachfolgender Umsetzung zur entsprechenden quarternären Ammoniumverbindung erhältlich sind.The amino compounds are generally used as such or as an acid addition compound in the form of a water-soluble salt. In the given case, the salts are obtained by neutralization, which can be carried out both with equimolar amounts and with a deficit of acids. Suitable acids are, for example, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid and formic acid.
The use of the ester quats together with fatty acid hydroxyethylimidazolines and / or fatty acid aminoethyl imidazolines and / or fatty acid aminoethanolamides and / or fatty acylamido fatty acid imidazolinium salts and / or carboxylic acid amidoalkylamines gives particularly good results in silicate flotation.
An important class of cationic compounds are the quaternary ammonium compounds. It is therefore preferred to use the ester quats together with quaternary ammonium compounds of the formula (IV)

where R ⁵ , R ⁶ , R ⁷ and R ^{8 represent} linear and / or branched alkyl and / or alkenyl radicals having 1 to 24 carbon atoms,
in a mixing ratio of 0.01: 1 to 100: 1. Trimethylalkyl (tallow) ammonium chloride (R ⁵ , R ⁶ R ⁷ = methyl, R ⁸ - C chain distribution of tallow fatty acids) or dimethyldicocoalkylammonium chloride (R ⁵ R ⁶ = methyl; R ⁷ R ⁸ = C chain distribution of coconut fatty acids) are preferred. admitted. These are mixtures of compounds of the formula (II), as are obtainable when working up fatty acid cuts such as, for example, tallow fatty acid or coconut fatty acid with subsequent reaction to give the corresponding quaternary ammonium compound.

The ampholytic surfactants that can be used as co-collectors are compounds which contain at least one anion-active and one cation-active group in the molecule, the anion-active group preferably from sulfonic acid or carboxyl groups and the cation-active group from amino groups, preferably from secondary or tertiary amino groups exist. In particular, sarcosides come as ampholytic surfactants, Taurides, N-substituted aminopropionic acids, alkylamidobetaines, imidazoliniumbetaines, Sulfobetaines and succinamates.

Anionic surfactants can be used in the sense of the invention if there is between the esterquats and the corresponding anionic surfactant not for flocculation is coming. This is usually the case if the esterquats contain one or more alkoxy groups, especially ethoxy groups. The production of such ethoxylated ester quats is described for example in DE-A1 42 24 714. A combination of these Accordingly, ester quats are, for example, with alkylbenzenesulfonates, alkanesulfonates, glycerol ether sulfonates, α-methyl ester sulfonates, sulfo fatty acids, alkyl sulfates, fatty alcohol ether sulfates, Glycerol ether sulfates, hydroxy mixed ether sulfates, monoglyceride (ether) sulfates, Fatty acid amide (ether) sulfates, sulfosuccinates, sulfosuccinates, sulfotriglycerides, ether carboxylic acids, Alkyl oligoglucoside sulfates, alkyl (ether) phosphates and protein fatty acid condensates possible.

In addition to the ester quats, nonionic surfactants can also be used. these include in particular the fatty alcohol polyglycol ethers, fatty amine polyglycol ethers, fatty acid amide polyglycol ethers, Fatty acid polyglycol esters, alkoxylated triglycerides, alkyl oligoglycosides, Sugar esters, sorbitan esters, polysorbates, polyol fatty acid esters, amine oxides, fatty acid alkanolamides, Alkyl lactams, fatty acid N-alkyl glucamides. Especially the add-on products of m moles of ethylene oxide and n moles of propylene oxide on fatty alcohols with 8 to 22 carbon atoms can be used, where m and n each represent numbers from 0 to 15.

For example, such ores, the individual components of which have so far been used separately cationic and anionic collectors in successive steps can be separated in one step by the collectors according to the invention, whereby Time and material costs can be reduced. Such a shared separation can be done, for example, when removing silicate and phosphate from iron ore.

wobei R⁹ für einen aliphatischen, linearen oder verzweigten Kohlenwasserstoffrest mit 6 bis 24 Kohlenstoffatomen und 0 und/oder 1, 2 oder 3 Doppelbindungen steht. Die Fettalkohole können zusammen mit den Esterquats und gegebenenfalls zusammen mit weiteren Co-Sammlern in einem Mischungsverhältnis von 0,1:1 bis 10:1 verwendet werden. Bevorzugt ist die Verwendung von Fettalkoholen mit 6 bis 8 C-Atomen, die gegebenenfalls als Verdünner für die erfindungsgemäßen Sammler und gleichzeitig als Schäumer eingesetzt werden können. Hierzu zählen insbesondere Isotridecanol und 2-Ethylhexanol.Advantageously, the esterquats can also be used in conjunction with fatty alcohols. Fatty alcohols are compounds of the formula (III)

where R ^{9 is} an aliphatic, linear or branched hydrocarbon radical having 6 to 24 carbon atoms and 0 and / or 1, 2 or 3 double bonds. The fatty alcohols can be used together with the esterquats and optionally together with other co-collectors in a mixing ratio of 0.1: 1 to 10: 1. Preferred is the use of fatty alcohols with 6 to 8 carbon atoms, which can optionally be used as thinners for the collectors according to the invention and at the same time as foaming agents. These include in particular isotridecanol and 2-ethylhexanol.

So-called foamers can be used to support foam formation Collectors with too little foaming tendency for a sufficiently high foam density and ensure a sufficiently long lifespan for the foam to ensure that it is as complete as possible Allow discharge of the loaded foam. Usually it will be when using the above mentioned collector or collector / co-collector systems may not be necessary, further Use foamer. In special cases, however, it may depend on the one used Flotation process may be necessary to intervene to regulate the foaming behavior. As Foamers are suitable here, for example, the alcohols, in particular aliphatic alcohols with 5 to 8 carbon atoms such as n-pentanol, isoamyl alcohol, hexanol, heptanol, Methyl isobutyl carbinol, caprylic alcohol, 4-heptanol have good foaming properties. Natural oils can also be used to support foam. In particular the alcohols, ethers and ketones such as e.g. α-terpineol, borneol, fennel alcohol, piperiton, Camphor, fenchone or 1,8-cineol have both collector and foaming properties. Also among the frothers are those that are non-ionic as part of the list Collectors mentioned polypropylene glycol ether.

Furthermore, the flotation aids according to the invention can contain further substances such as pushers, activators, pH regulators and dispersants.

To the pushers that can be used effectively in the sense of the invention, include, for example, naturally occurring polysaccharides such as guar, starch and Cellulose. Quebracho, tannin, dextrin (white dextrin, British gum, Yellow dextrin) and other chemical derivatives. These include derivatives in particular the starch, guar and cellulose molecules, their hydroxyl groups with a wide range of anionic, cationic and nonionic functionalities can be equipped. Typical anionic derivatives are carboxylates, sulfates, sulfonates, xanthates, phosphates. Typical cationic derivatives are epoxypropyl trimethyl ammonium salts, while nonionic Compounds mainly used methyl, hydroxyethyl and hydroxypropyl derivatives become.

In a preferred embodiment, the ester quats are used in silicate flotation. The invention therefore furthermore relates to flotation aids containing esterquats of the formula (I) as defined above. In particular, the ester quats, as well as fatty alcohols and / or quaternary ammonium compounds of the formula (II) are contained in the flotation aids according to the invention. To adjust the rheological behavior, the flotation aids according to the invention can contain solvents in a proportion of 0.1 to 40% by weight, preferably 1 to 30% by weight and particularly preferably 2 to 15% by weight.
Suitable solvents are both the alcohols of the C chain length 5 to 8 already described in another context, but alcohols with a lower chain length can also be used as solvents. The flotation aids according to the invention can contain minor amounts of glycols such as ethylene glycol, propylene glycol or butylene glycol, but also monofunctional linear or branched alcohols such as ethanol, n-propanol or iso-propanol.

Examples

OMC 6317

= Schäumer (Fa. Henkel)

OMC6024

= Schäumer (Fa. Henkel)

AU 46

= Biologisch abbaubarer Esterquat (Fa Henkel)

AU 56

= Biologisch abbaubarer Esterquat (Fa Henkel)

DKMA

= Dikokosalkyldimethylammoniumchlorid

TTAC

=Trimethyltalgammoniumchlorid

OMC 5044

= Kationischer Sammler von Henkel

A = Austrag AG = Aufgabe F = flotiertes Material conc. = Rest

Korngrößenverteilung: > 40 µm: >50 Gew.-%

Silikate: ca. 1.5 bis 2.5 Gew.-%

Calzit: ca. 97.5 bis 98.5 Gew.-%

Wirksamkeit verschiedener Sammler bei erhöhter Magnesiumkonzentration Produkt AS % Zugabe AS Einwaage Produkt g Testlösung Schaumhöhe (ml) Halbwertzeit min (Dez.) AU 46 90 1 % 2,26 2 % MgCl₂-Lsg. 220 2:35 (2,58) 2,29 2 % MgCl₂-Lsg. 220 2:35 (2,58) AU 36 85 1 % 2,38 2 % MgCl₂-Lsg. 220 3:40 (3,67) 2,45 2 % MgCl₂-Lsg. 220 3:40 (3,67) DKMA 77 1 % 2,6 2 % MgCl₂-Lsg. 220 Schaum stabil 2,6 2 % MgCl₂-Lsg. 220 Schaum stabil TTAC 52 1 % 3,85 2 % MgCl₂-Lsg. 840 6:10 (6,17) 3,85 2 % MgCl₂-Lsg. 850 6:10 (6,17) AU 46 90 1 % 2,27 5 % MgCl₂-Lsg. 220 0:30 (0,5) 2,54 5 % MgCl₂-Lsg. 220 0:30 (0,5) AU 36 85 1 % 2,37 5 % MgCl₂-Lsg. 220 0:20 (0,33) 2,39 5 % MgCl₂-Lsg. 220 0:20 (0,33) DKMA 77 1 % 2,6 5 % MgCl₂-Lsg. 220 Schaum stabil TTAC 52 1 % 3,85 5 % MgCl₂-Lsg. 820 7:20 (7,33) 3,85 5 % MgCl₂-Lsg. 820 7:20 (7,33) Tabelle 2 zeigt, daß einzig die erfindungsgemäßen Sammler zu leicht brechenden Schäumen mit geringer Halbwertzeit führen, wie sie bei der Erzflotation wünschenswert sind. The following examples illustrate the effectiveness of the collectors according to the invention on the one hand in the flotation of silicate-containing ore materials and on the other hand in the flotation with increased magnesium concentrations.
Table 1 shows the results of various flotation aids in which at least one collector according to the invention is contained. Table 2 shows the effectiveness of various types of collectors, both according to the invention and conventionally, under conditions of increased magnesium concentrations.

OMC 6317

= Foamer (Henkel)

OMC6024

= Foamer (Henkel)

AU 46

= Biodegradable esterquat (Fa Henkel)

AU 56

= Biodegradable esterquat (Fa Henkel)

DKMA

= Dicocoalkyldimethylammonium chloride

TTAC

= Trimethyl tallow ammonium chloride

OMC 5044

= Cationic collector from Henkel

A = Discharge AG = Task F = floated material conc. = Rest

Grain size distribution:> 40 µm:> 50% by weight

Silicates: approx. 1.5 to 2.5% by weight

Calcite: approx. 97.5 to 98.5% by weight

Effectiveness of different collectors with increased magnesium concentration product AS% Add AS Weighing product g Test solution Foam height (ml) Half-life min (Dec.) AU 46 90 1 % 2.26 2% MgCl ₂ solution. 220 2:35 (2.58) 2.29 2% MgCl ₂ solution. 220 2:35 (2.58) AU 36 85 1 % 2.38 2% MgCl ₂ solution. 220 3:40 (3.67) 2.45 2% MgCl ₂ solution. 220 3:40 (3.67) DKMA 77 1 % 2.6 2% MgCl ₂ solution. 220 Foam stable 2.6 2% MgCl ₂ solution. 220 Foam stable TTAC 52 1 % 3.85 2% MgCl ₂ solution. 840 6:10 (6.17) 3.85 2% MgCl ₂ solution. 850 6:10 (6.17) AU 46 90 1 % 2.27 5% MgCl ₂ solution. 220 0:30 (0.5) 2.54 5% MgCl ₂ solution. 220 0:30 (0.5) AU 36 85 1 % 2.37 5% MgCl ₂ solution. 220 0:20 (0.33) 2.39 5% MgCl ₂ solution. 220 0:20 (0.33) DKMA 77 1 % 2.6 5% MgCl ₂ solution. 220 Foam stable TTAC 52 1 % 3.85 5% MgCl ₂ solution. 820 7:20 (7.33) 3.85 5% MgCl ₂ solution. 820 7:20 (7.33) Table 2 shows that only the collectors according to the invention lead to easily breaking foams with a short half-life, as are desirable in ore flotation.

Claims (2)

Process for removing mineral impurities, in particular silicates, from ore mixtures by flotation, by mixing ground ore mixture with water to form a suspension, introducing air into the suspension in the presence of a flotation aid and separating the foam formed together with the flotated impurities contained therein that quaternized ester compounds (ester quats) of the general formulas (I)

where R ¹ CO for an acyl radical with 6 to 24 carbon atoms, R ² for R ¹ CO, R ³ R ⁴ and R ⁵ independently of one another for alkyl radicals with 1 to 4 carbon atoms, m and n in total for 0 or numbers from 1 to 12 and X represents halide, alkyl sulfate or alkyl phosphate,
individually or in a mixture, optionally together with other anionic, cationic, amphoteric and / or nonionic substances as collector component. Process according to Claim 1, characterized in that ester quats described by the formulas (I) together with quaternary ammonium compounds (QAV) of the formula (II),

where R ⁵ , R ⁶ , R ⁷ and R ^{8 represent} linear and / or branched alkyl and / or alkenyl radicals having 1 to 24 carbon atoms,
in a mixing ratio of esterquat: QAV from 0.01: 1 to 100: 1.