EP0270933B1 - Surfactant mixtures as collectors for the flotation of non-sulfidic minerals - Google Patents

Description

The invention relates to the use of end-capped fatty alcohol polyethylene glycol ethers as co-collectors in the flotation of non-sulfidic ores together with anionic surfactants.

To separate valuable minerals from the gangue, flotation is a generally used sorting process for the processing of mineral ores. Non-sulfidic minerals for the purposes of the present invention are, for example, apatite, fluorite, scheelite, barite, iron oxides and other metal oxides, for example the oxides of titanium and zirconium, and certain silicates and aluminosilicates. Usually, in the case of flotative processing methods, the ore is first crushed and dry, but preferably wet, and suspended in water. Subsequently, collectors are usually added, often in connection with foaming agents and possibly other auxiliary reagents such as regulators, pushers (deactivators) and / or stimulants (activators), which support the separation of the valuable minerals from the gangue minerals in the ore during the subsequent flotation. Before air is blown into the suspension (flotation) to produce foam on its surface, these reagents are usually allowed to act on the finely ground ore for a certain time (conditioning). The collector ensures that the surface of the minerals is rendered hydrophobic, so that these minerals adhere to the surface gas bubbles formed during ventilation are caused. The mineral components are made hydrophobic selectively in such a way that the undesirable components of the ore do not adhere to the gas bubbles. The mineral-containing foam is stripped off and processed. The aim of the flotation is to obtain the mineral of value of the ores in the highest possible yield and at the same time to obtain the best possible enrichment of the mineral.

Anion and cationic surfactants are primarily used as collectors in the flotative processing of ores. Known anionic collectors are, for example, saturated and unsaturated fatty acids, alkyl sulfates, alkyl ether sulfates, alkyl sulfosuccinates, alkyl sulfosuccinamides, alkyl benzene sulfonates, alkyl sulfonates, petroleum sulfonates, acyl lactylates, alkyl phosphates and alkyl ether phosphates.

In contrast to anionic and cationic surfactants, nonionic surfactants are hardly used as collectors in flotation. A. Doren, D. Vargas and J. Goldfarb report in Trans. Inst. Met. Min. Sect. C 84 (1975), pages 34 to 39 about flotation experiments on quartz, cassiterite and chrysocolla, which were carried out with an adduct of 9 to 10 moles of ethylene oxide with octylphenol as a collector. In the relevant literature, combinations of ionic and nonionic surfactants are also occasionally described as collectors. For example, A. Doren, A. van Lierde and JA de Cuyper report in Dev. Min. Proc. 2 (1979), pages 86 to 109 about flotation tests which were carried out on non-sulfidic tin ore with a combination of an adduct of 9 to 10 mol of ethylene oxide with octylphenol and an octadecylsulfosuccinate. VM Lovell describes in AM Gaudin Memorial Volume, published by MG Fuerstenau, AIME, New York, 1976 Vol. 1, pages 597 to 620 flotation experiments involving apatite with a Combination of tall oil fatty acid and nonylphenol tetraglycol ether were performed.

The anionic collectors used for flotation in many cases do not lead to a satisfactory application of the valuable minerals with economically justifiable collector quantities.

The present invention was therefore based on the object of finding improved collectors in the sense of an economical design of the flotation processes, with which larger yields of valuable minerals are achieved either with constant collector quantities and constant selectivity, or, at least with constant collector quantities, at least constant valuable mineral yields.

It has been found that certain end-capped fatty alcohol polyethylene glycol ethers are very effective additives to anionic surfactants, which are known as collectors for the flotation of non-sulfidic ores, in the sense of co-collectors.

• a) mindestens einem Alkyl-oder Alkenylpolyethylenglykolether, der durch hydrophobe Reste endgruppenverschlossen ist, und
• b) mindestens einem anionaktiven Tensid

als Sammler bei der Flotation von nichtsulfidischen Erzen.The present invention relates to the use of mixtures of

• a) at least one alkyl or alkenyl polyethylene glycol ether which is end group-capped by hydrophobic radicals, and
• b) at least one anionic surfactant

as a collector in the flotation of non-sulfidic ores.

Component a) is in particular alkyl or alkenyl polyethylene glycol ether of the formula I,



R¹ - O - (CH₂CH₂O) _n - R² I



in which R¹ is a straight-chain or branched alkyl or alkenyl radical having 8 to 22 carbon atoms, R² is a straight-chain or branched alkyl radical having 1 to 8 carbon atoms or a benzyl radical and n is a number from 1 to 30.

The end group-capped alkyl or alkenyl polyethylene glycol ethers defined above represent a class of substances known from the literature; they can be obtained by known methods of organic synthesis, see for example US-A-2,856,434, DE-B-15 20 647, DE-A-25 56 527, DE-A-30 11 237, EP-A-00 30 397 and DE-A-33 15 951). These end group-capped alkyl or alkenyl polyethylene glycol ethers are more chemically stable than the corresponding polyglycol ethers with a free hydroxyl group, especially in an alkaline medium. Since such blocked alkyl or alkenyl polyglycol ethers also foam less in aqueous solutions than their starting compounds, they have a certain importance for (alkaline) cleaning processes with heavy use (see, for example, DE-A-33 15 951).

Known fatty alcohols can be used as starting materials for the preparation of the end-capped alkyl or alkenyl polyethylene glycol ethers to be used according to the invention. The fatty alcohol component can consist of straight-chain and branched saturated and unsaturated compounds of this category with 8 to 22 carbon atoms, for example n-octanol, n-decanol, n-dodecanol, n-tetradekanol, n-hexadecanol, n-octadecanol, n-eikosanol, n-docosanol, n-hexadecenol, n-octadecenol, isotridecanol and isooctadecanol. The fatty alcohols mentioned can individually form the basis for the end-capped alkyl or alkenyl polyethylene glycol ethers. As a rule, however, products are based on fatty alcohol mixtures used, which derive from the fatty acid content of fats and oils of animal or vegetable origin. As is known, such fatty alcohol mixtures can be obtained from the native fats and oils, inter alia via the transesterification of the triglycerides with methanol and subsequent catalytic hydrogenation of the fatty acid methyl esters. Both the fatty alcohol mixtures obtained in the production process and suitable fractions with a limited chain length spectrum can serve as the basis for the production of the end-capped alkyl or alkenyl polyethylene glycol ethers. In addition to the fatty alcohol mixtures obtained from natural fats and oils, synthetically obtained fatty alcohol mixtures, for example the known Ziegler and oxo fatty alcohols, are also suitable as starting materials for the production.

In the surfactant mixtures to be used according to the invention, alkyl or alkenyl polyethylene glycol ethers based on fatty alcohols having 12 to 18 carbon atoms, ie. H. such compounds of formula I are used in which R¹ corresponds to an alkyl or alkenyl radical having 12 to 18 carbon atoms.

In the preparation of the end-capped alkyl or alkenyl polyethylene glycol ethers, 1 to 30, preferably 2 to 15, moles of ethylene oxide per mole of fatty alcohol are added to the fatty alcohols mentioned. The reaction with ethylene oxide takes place under the known alkoxylation conditions, preferably in the presence of suitable alkaline catalysts.

The etherification of the free hydroxyl groups required for the end group closure of the alkyl or alkenyl polyethylene glycol ether can be carried out according to the methods described in the literature (for example from US Pat. No. 2,856,434, DE-B-15 20 647, DE-A-25 56 527, DE-A -30 11 237, EP-A-00 30 397 and DE-A-33 15 951) known processes. Etherification is preferred the free hydroxyl groups under the known conditions of Williamson's ether synthesis with straight-chain or branched C₁ to C₈ alkyl halides or benzyl halides, for example with n-propyl iodide, n-butyl chloride, sec.-butyl bromide, tert.-butyl chloride, amyl chloride, tert.-amyl bromide, n-hexyl chloride, n-heptyl bromide, n-octyl chloride and benzyl chloride. It can be expedient to use organic halide and alkali in a stoichiometric excess, for example from 100 to 200%, over the hydroxyl groups to be etherified. A corresponding method is described in DE-A-33 15 951. In the context of the present invention, preference is given to using alkyl or alkenyl polyethylene glycol ethers which are end group-capped with n-butyl groups.

In the surfactant mixtures to be used according to the invention, anionic surfactants are known as components b), which are known per se as collectors for the flotation of non-sulfidic ores. These are, in particular, anionic surfactants selected from the group consisting of fatty acids, alkyl sulfates, alkyl ether sulfates, alkyl sulfosuccinates, alkyl sulfosuccinamides, alkyl benzene sulfonates, alkyl sulfonates, petroleum sulfonates, acyl lactylates, alkyl phosphates and alkyl ether phosphates.

The fatty acids here are, in particular, the straight-chain fatty acids with 12 to 18 carbon atoms, in particular those with 16 to 18 carbon atoms, obtained from vegetable or animal fats and oils, for example by fat splitting and optionally fractionation and / or separation by the crosslinking process. Oleic acid and tall oil fatty acid are of particular importance here.

Suitable alkyl sulfates are the water-soluble salts of sulfuric acid semiesters of fatty alcohols with 8 to 22 carbon atoms, preferably of fatty alcohols with 12 to 18 carbon atoms, which can be straight-chain or branched. The preceding statements about the fatty alcohol component of the alkyl or alkenyl polyethylene glycol ether defined under a) apply mutatis mutandis to the fatty alcohol component of the sulfuric acid half-esters. The sodium salts are preferably considered as water-soluble salts.

Suitable fatty alcohol ether sulfates are the known water-soluble salts of sulfuric acid semiesters based on addition products of 1 to 30 mol, preferably 2 to 15 mol, of ethylene oxide with fatty alcohols having 8 to 22, preferably 12 to 18, carbon atoms. For the fatty alcohol component of the fatty alcohol ether sulfates, the information on the fatty alcohol component of the end group-capped alkyl or alkenyl polyethylene glycol ethers correspondingly applies. Sodium salts are particularly suitable as water-soluble salts.

Suitable alkylsulfosuccinates are sulfosuccinic acid semiesters of fatty alcohols having 8 to 22, preferably 12 to 18, carbon atoms. Such alkyl sulfosuccinates can be obtained, for example, by reacting corresponding fatty alcohols or fatty alcohol mixtures with maleic anhydride and subsequent addition of alkali metal sulfite or alkali metal bisulfite. For the fatty alcohol component of the sulfosuccinic acid semi-esters, the information on the fatty alcohol component of the end group-capped alkyl or alkenyl polyethylene glycol ether defined in a) applies in turn. The alkyl sulfosuccinates are preferably used as sodium and ammonium salts.

in der R einen Alkyl- oder Alkenylrest mit 8 bis 22, vorzugsweise 12 bis 18 Kohlenstoffatomen, R' Wasserstoff oder einen Alkylrest mit 1 bis 3 Kohlenstoffatomen und M ein Wasserstoffion, ein Alkalimetallkation, oder ein Ammoniumion, vorzugsweise ein Natrium-oder Ammoniumion darstellen. Die Alkylsulfosuccinamide der Formel II stellen bekannte Substanzen dar, die beispielsweise durch Umsetzung von entsprechenden primären oder sekundären Aminen mit Maleinsäureanhydrid, nachfolgende Anlagerung von Alkalimetallsulfit oder Alkalimetallhydrogensulfit erhalten werden. Für die Herstellung der Alkylsulfosuccinamide geeignete primäre Amine sind beispielsweise n-Octylamin, n-Decylamin, n-Dodecylamin, n-Tetradecylamin, n-Hexadecylamin, n-Octadecylamin, n-Eikosylamin, n-Docosylamin, n-Hexadecenylamin und n-Octadecenylamin. Die genannten Amine können einzeln die Basis der Alkylsulfosuccinamide bilden. Normalerweise werden zur Herstellung der Alkylsulfosuccinamide jedoch Amingemische eingesetzt, deren Alkylrest aus dem Fettsäureanteil von Fetten und Ölen tierischen oder pflanzlichen Ursprungs herstammen. Solche Amingemische lassen sich bekanntlich aus den durch Fettspaltung gewonnenen Fettsäuren der nativen Fette und Öle über die zugehörigen Nitrile durch Reduktion mit Natrium und Alkoholen oder durch katalytische Hydrierung gewinnen. Als sekundäre Amine eignen sich für die Herstellung der Alkylsulfosuccinamide der Formel II insbesondere die N-Methyl- und N-Ethylderivate der oben genannten primären Amine.The alkylsulfosuccinamides considered as possible component b) correspond to the formula II,

in which R is an alkyl or alkenyl radical having 8 to 22, preferably 12 to 18 carbon atoms, R 'is hydrogen or an alkyl radical with 1 to 3 carbon atoms and M is a hydrogen ion, an alkali metal cation, or an ammonium ion, preferably a sodium or ammonium ion. The alkylsulfosuccinamides of the formula II are known substances which are obtained, for example, by reacting corresponding primary or secondary amines with maleic anhydride, followed by addition of alkali metal sulfite or alkali metal bisulfite. Primary amines suitable for the preparation of the alkylsulfosuccinamides are, for example, n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine, n-eikosylamine, n-docosylamine, n-hexadecenylamine and n-octadecenylamine. The amines mentioned can individually form the basis of the alkylsulfosuccinamides. Normally, however, amine mixtures are used to prepare the alkylsulfosuccinamides, the alkyl radical of which derives from the fatty acid content of fats and oils of animal or vegetable origin. As is known, such amine mixtures can be obtained from the fatty acids of native fats and oils obtained by fat cleavage via the associated nitriles by reduction with sodium and alcohols or by catalytic hydrogenation. Particularly suitable secondary amines for the preparation of the alkylsulfosuccinamides of the formula II are the N-methyl and N-ethyl derivatives of the above-mentioned primary amines.

Alkylbenzenesulfonates corresponding to formula III suitable for use as component b),



R - C₆H₄ - SO₃M III



in which R is a straight-chain or branched alkyl radical having 4 to 16, preferably 8 to 12 carbon atoms and M is an alkali metal cation or ammonium ion, preferably a sodium ion.

Alkyl sulfonates which are suitable for use as component b) correspond to the formula IV,



R - SO₃M IV



in which R represents a straight-chain or branched alkyl radical, preferably 12 to 18 carbon atoms, and M represents an alkali metal cation or an ammonium ion, preferably a sodium ion.

The petroleum sulfonates suitable for use as component b) are obtained from lubricating oil fractions, usually by sulfonation with sulfur trioxide or oleum and subsequent neutralization with sodium hydroxide solution. Compounds in which the hydrocarbon radicals predominantly have chain lengths in the range from 8 to 22 carbon atoms are particularly suitable here.

in der R einen aliphatischen, cycloaliphatischen oder alicyclischen Rest mit 7 bis 23 Kohlenstoffatomen und X ein salzbildendes Kation bedeuten. R ist vorzugsweise ein aliphatischer, linearer oder verzweigter Kohlenwasserstoffrest, der gesättigt, einfach oder mehrfach ungesättigt und gegebenenfalls mit Hydroxylgruppen substituiert sein kann. Die Verwendung der Acyllactylate der Formel V als Sammler bei der Flotation nichtsulfidischer Erze ist in DE-OS 32 38 060 beschrieben.The acyl lactylates also considered as possible component b) correspond to the formula V,

in which R is an aliphatic, cycloaliphatic or alicyclic radical having 7 to 23 carbon atoms and X is a salt-forming cation mean. R is preferably an aliphatic, linear or branched hydrocarbon radical which can be saturated, mono- or polyunsaturated and optionally substituted by hydroxyl groups. The use of the acyl lactylates of the formula V as a collector in the flotation of non-sulfidic ores is described in DE-OS 32 38 060.

und

in denen R einen Alkyl- oder Alkenylrest mit 8 bis 22 Kohlenstoffatomen und M ein Wasserstoffion, ein Alkalimetallkation oder ein Ammoniumion, vorzugsweise ein Natrium- oder Ammoniumion darstellen. Die Indices m, n und o sind im Falle der Alkylphosphate gleich Null, im Falle der Alkyletherphosphate bedeuten sie ganze Zahlen von 2 bis 15.The alkyl phosphates and alkyl ether phosphates considered as possible component b) correspond to the formulas V and VI,

and

in which R represents an alkyl or alkenyl radical having 8 to 22 carbon atoms and M represents a hydrogen ion, an alkali metal cation or an ammonium ion, preferably a sodium or ammonium ion. The indices m, n and o are zero in the case of alkyl phosphates, and in the case of alkyl ether phosphates they are integers from 2 to 15.

The compounds of the formulas V and VI are known substances which are obtained by customary methods of organic synthesis can be. Suitable starting materials for the preparation of the alkyl phosphates are the straight-chain or branched alcohols having 8 to 22 carbon atoms described above in connection with the alkyl sulfates or sulfuric acid semiesters. Alkyl phosphates in which the radical R has 10 to 16 carbon atoms are particularly preferred. Addition products of 2 to 15 moles of ethylene oxide onto the abovementioned alcohols with 8 to 22 carbon atoms come into consideration as starting material for the production of the alkyl ether phosphates, which in turn can be obtained by known methods of organic synthesis. In the case of the alkyl ether phosphates, preference is given to compounds of the formulas V and VI in which the radical R has 18 to 22 carbon atoms.

The mono- and dialkyl phosphates defined above can each be used individually as component b) in the sense of the invention. However, preference is given to using mixtures of mono- and dialkylphosphates which are obtained in the industrial production of such compounds. The same applies analogously to the alkyl ether phosphates defined by the formulas V and VI.

In the mixtures of end-capped alkyl or alkenyl polyethylene glycol ethers and anionic surfactants to be used according to the invention, the weight ratio of components a): b) is in the range from 1:20 to 3: 1, preferably in the range from 1:10 to 1: 1.

The surfactant mixture must be used in a certain minimum amount in order to achieve economically useful results in the flotation of non-sulfidic ores. However, a maximum amount of surfactant must also not be exceeded, since otherwise the foam formation becomes too strong and the selectivity towards the valuable minerals decreases.

The amounts in which the collector mixtures to be used according to the invention are used depend in each case on the type of ores to be floated and on their content of valuable minerals. As a result, the amounts required can vary within wide limits. In general, the collector mixtures according to the invention are used in amounts of 50 to 2000, preferably 100 to 1500 g per ton of raw ore.

In practice, the mixtures to be used according to the invention are used in the known flotation processes for non-sulfidic ores instead of known collectors. Accordingly, in addition to the collector mixtures described, the customary reagents such as foaming agents, regulators, activators, deactivators, etc. are also added to the aqueous slurries of the ground ores. The flotation is carried out under the conditions of the methods of the prior art. In this context, reference is made to the following references on the technological background of ore processing: H. Schubert, processing of solid mineral substances, Leipzig 1967; B. Wills, Mineral Processing Technology Plant Design, New York, 1978; D. B. Purchas (ed.), Solid / Liquid Separation Equipment Scale-up, Croydon 1977; E. S. Perry, C. J. van Oss, E. Grushka (ed.), Separation and Purification Methods, New York 1973 to 1978.

• a) mindestens einem Alkyl- oder Alkenylpolyethylenglykolether, der durch hydrophobe Reste endgruppenverschlossen ist, und
• b) mindestens einem anionaktiven Tensid

einsetzt.The invention further relates to a process for separating non-sulfidic minerals from an ore by flotation, in which ground ore is mixed with water to form a suspension, air is passed into the suspension in the presence of a collector system and the resulting foam is separated off together with the mineral contained therein . This process is characterized in that mixtures are formed as collectors

• a) at least one alkyl or alkenyl polyethylene glycol ether which is end group-capped by hydrophobic radicals, and
• b) at least one anionic surfactant

starts.

A preferred area of use for the collector mixtures to be used according to the invention is the processing of ores such as Scheelite, barite, apatite or iron ores.

The following examples show the superiority of the mixtures of end-capped alkyl or alkenyl polyethylene glycol ethers and anionic surfactants to be used according to the invention compared to known collector components from the prior art.

Under laboratory conditions, an increased concentration of collectors was sometimes used, which in practice can sometimes fall significantly below the level. The possible uses and conditions of use are therefore not limited to the separation tasks and test conditions described in the examples. Unless otherwise stated, all percentages are in percent by weight. The amounts of reagents are based on the active substance.

example 1

As a flotation task, a Scheelite ore from Austria was used, which had the following chemical composition with regard to the main components: WO₃ 0.3% CaO 8.8% SiO₂ 55.8%

The ore sample had the following grain size distribution: 28% <25 µm 43% 25-100 µm 29% 100-200 µm

The collector mixture used contained the sodium salt of an N-C₁₂₋₁₈ alkyl sulfosuccinamide as an anionic component. As a nonionic component, a fatty alcohol polyethylene glycol n-butyl ether based on an adduct of 7 moles of ethylene oxide and a fatty alcohol mixture of chain length C₁₂ to C₁₈ was used. The weight ratio of anionic component to nonionic component was 2: 1.

The flotation tests were carried out using a Humbold-Wedag laboratory flotation machine from KHD Industrieanlagen AG, Humbold-Wedag, Cologne (see Seifen-Fette-Wachsen 105 (1979), page 248) in a 1 l flotation cell. Deionized water was used to make the slurry. The cloud density was 400 g / l. Water glass with a dosage of 2000 g / t was used as the pusher. The conditioning time of the pusher was 10 min a stirring speed of 2000 rpm. It was floated at the pH value of approximately 9.5 resulting from the addition of water glass. The type of collector dosage is shown in Table 1. The conditioning time of the collector was 3 minutes.

Comparative Example 1

A flotation test according to Example 1 was carried out using only the alkylsulfosuccinamide from Example 1 as a collector. The data obtained are shown in Table 1.

Comparative Example 2

A flotation test was carried out according to Example 1 using a collector mixture of the alkylsulfosuccinamide mentioned in Example 1 and an adduct of 2 moles of ethylene oxide and 4 moles of propylene oxide with an alcohol mixture of chain length C₁₂ / C₁₈ in a weight ratio of 2: 1. The results of the flotation are shown in Table 1.

As can be seen from Table 1, the combination of the anionic surfactant with an end-capped fatty alcohol polyethylene glycol ether according to Example 1 with a 40% reduced collector dosage can extremely increase the output of WO₃, the selectivity also being more favorable. Compared to a mixture of alkylsulfosuccinamide and fatty alcohol alkoxylate according to Comparative Example 2, the collector mixture according to the invention also has clear advantages in terms of selectivity and output.

Example 2

The same flotation task as in Example 1 was used.

The collector mixture used contained as an anionic component the alkylsulfosuccinamide from Example 1 and a fatty alcohol polyethylene glycol n-butyl ether based on an adduct of 5 moles of ethylene oxide with a fatty alcohol mixture of chain length C₁₂ to C₁₈ in a weight ratio of 2: 1.

The flotation experiments were carried out in a modified Hallimond tube (microflotation cell) according to B. Dobias, Colloid & Polymer Science, 259 (1981), pages 775 to 776 at room temperature. 2 g of ore were used for each test. Distilled water was used to prepare the slurry. The conditioning time was 15 minutes each. During the flotation, a flow of air was passed through the slurry at a flow rate of 4 ml / min. The flotation time was 2 min in all experiments.

The data obtained are shown in Table 2.

Example 3

The same flotation task as in Example 1 was used.

The collector mixture used contained as the anionic component the alkylsulfosuccinamide from Example 1 and a fatty alcohol polyethylene glycol n-butyl ether based on an adduct of 10 moles of ethylene oxide with a fatty alcohol mixture of chain length C₁₂ to C₁₈ in a weight ratio of 2: 1. The flotation was among those in the example 2 specified conditions carried out.

The results of the flotation are shown in Table 2.

Comparative Example 3

The same flotation task as in Example 1 was used.

The collector mixture used contained as an anionic component the alkylsulfosuccinamide from Example 1 and an adduct of 2 moles of ethylene oxide and 4 moles of propylene oxide with a fatty alcohol mixture of chain length C₁₂ to C₁₈ in a weight ratio of 2: 1. The flotation was carried out under the conditions given in Example 2.

The data from the flotation test can be found in Table 2.
The test results in Table 2 show that mixtures with fatty alcohol polyethylene glycol n-butyl ethers of different degrees of ethoxylation are superior to a corresponding collector mixture with a fatty alcohol alkoxylate as a nonionic component as a nonionic component with regard to the flotation result.

Example 4

The waste from an iron ore processing plant in Sweden was used as a flotation task, which had the following chemical composition with regard to the main components: 11.6% P₂O₅ 34.9% SiO₂ 13.0% Fe₂O₃ 18.9% MgO

Grain size distribution of the flotation task: <25 µm 5.7% 25-100 µm 15.0% 100 - 500 µm 69.8% 500 - 1000 µm 8.7% > 1000 µm 0.8%

The Na / NH₄ salt of a monoalkylsulfosuccinate, the alkyl radical of which is derived from an industrial oleyl / cetyl alcohol, was used as the anionic collector component b). As component a), a fatty alcohol polyethylene glycol n-butyl ether based on an adduct of 7 moles of ethylene oxide with a fatty alcohol mixture of chain length C₁₂ to C₁₈ was chosen, a ratio from 65% of the Na / NH₄ salt to 35% of the end-capped fatty alcohol polyethylene glycol butyl ether was present.

The flotation tests were carried out in a laboratory flotation cell (model D-1 from Denver Equipment with a capacity of 1 l) at room temperature. Tap water with a hardness of 16 ° dH was used to produce the slurry. The turbidity was 500 g / l, and the pH was adjusted to 9.5 with sodium hydroxide solution before the collector was added. After the pre-flotation (duration 6 min), the pre-concentrate was cleaned twice. Flotation was carried out at 1,200 rpm in all stages.

The flotation results are shown in Table 3.

Comparative Example 4

The same flotation task as in Example 4 was used.

The Na / NH₄ salt of a monoalkyl sulfosuccinate described in Example 4 was used as the collector. The flotation was carried out under the conditions given in Example 4. The data can be found in Table 3.

Comparative Example 5

The same flotation task as in Example 4 was used.

The collector mixture used contained as an anionic component the Na / NH₄ salt of a monoalkyl sulfosuccinate and an adduct of 2 moles of ethylene oxide and 4 moles of propylene oxide with a fatty alcohol mixture of chain length C₁₂ to C₁₈. The collector mixture consisted of 65% of the anionic Surfactants and 35% of the fatty alcohol ethoxylate. The flotation was carried out under the conditions given in Example 4. The flotation results are shown in Table 3.

The flotation tests shown in Table 3 clearly show that the collector combination according to Example 4 enables the collector dosage to be reduced by approximately 30% with increased mineral output. A corresponding collector mixture according to Comparative Example 5 only achieves a significantly lower apatite output.

Example 5

The flotation task was a barite ore from France with a high proportion of sludge, with the following main components: 39% BaSO₄ 6.5% Fe₂O₃ 41.8% SiO₂

Grain size distribution of the flotation task: <25 µm 87.2% 25 - 40 µm 10.7% > 40 µm 2.1%

The sodium salt of a fatty alcohol ether sulfate based on an adduct of 3 moles of ethylene oxide and a saturated fatty alcohol of chain length C₁₂ to C₁₈ was used as the anionic component, and a fatty alcohol polyethylene glycol n-butyl ether based on an adduct of 7 moles of ethylene oxide with a fatty alcohol was used as the end-capped nonionic surfactant Chain length C₁₂ to C₁₈ in a weight ratio of 9: 1.

The experiments were again carried out in the Denver Model D-1 laboratory flotation cell. The float was at a turbidity of 500 g / l in tap water at 16 ° dH and at one pH value of 9.5, which is set by the addition of water glass. The water glass dosage was 3000 g / t. After the pre-flotation (duration 6 min), the pre-concentrate was cleaned twice. Flotation was carried out at 1,200 rpm in all stages.

Comparative Example 6

The fatty alcohol ether sulfate from Example 5 was used as the collector. The flotation was carried out under the conditions given in Example 5. The results of the flotation are shown in Table 4.

Comparative Example 7

The same flotation task as in Example 5 was used.

The collector used was a commercially available collector for barite flotation based on petroleum sulfonate. The flotation was carried out under the conditions given in Example 5. The data from the flotation test are shown in Table 4.

Compared to the fatty alcohol ether sulfate used alone, the collector combination according to Example 5 enables the collector dosage to be reduced by 20% - without loss of barite output.

In comparison, the commercially available petroleum sulfonate collector achieves only a very low baryte output despite the considerably higher collector consumption.

Example 6

A fluorite ore was used as the flotation task, which had the following composition with regard to the main components: CaF₂ 70% SiO₂ 12% CaCO₃ 10%.

The flotation task had the following grain size distribution: <25 µm 45.2% 25-63 µm 29.9% 63-100 µm 25.0% > 100 µm 0.9%.

The collector mixture used according to the invention contained technical oleic acid as the anion-active component. A fatty alcohol polyethylene glycol n-butyl ether, based on an adduct of 5 moles of ethylene oxide and one mole of a fatty alcohol mixture of chain length C₁₂ to C₁₈, was used as the nonionic component. The weight ratio of anionic component to nonionic component was 7: 3. The total dosage of the collector mixture was 300 g / t.

The flotation was carried out in a laboratory flotation machine from Denver Equipment (model D 1 with a 1 l cell). The turbidity was 500 g / l for the pre-flotation and 300 g / l for the cleaning flotation.

Quebracho was used as the pusher, the total dosage being 1,500 g / t, which was added in equal parts (500 g / t each) in the 3 steps of the cleaning flotation.

The turbidity temperature was 30 ° C in all flotation stages. The pH of the slurry ranged from 8 to 8.5. The conditioning time for pushers and collectors was 5 minutes each. The conditioning was carried out at a stirring speed of 1400 rpm. The flotation was carried out at 1200 rpm. The flotation time was 6 minutes.

The results of the flotation are shown in Table 5.

Comparative Example 8

The same flotation task as in Example 6 was used.

The technical oleic acid mentioned in Example 6 was used as a collector in a total dosage of 650 g / t. The flotation was carried out under the conditions given in Example 6. The results of the flotation are shown in Table 5. Table 5 Flotation of fluorite example Total dosage (g / t) CaF₂ output (%) Concentrate content CaF₂ (%) Example 6 300 88 93.3 Comparative Example 8 650 89 92.3

The flotation results shown in Table 5 show that the collector combination according to the invention according to Example 6 enables a considerable reduction in the collector dosage without reducing the mineral mineral output and with the concentrate content remaining the same.

Example 7

A baryter ore was used as the flotation task, which had the following main components: Barite 65% Silicates 20% Iron oxides 10%.

The grain size distribution of the flotation task was 100% <75 µm.

The collector mixture used for flotation according to the invention contained as an anionic component a sodium alkyl sulfate, the alkyl radical of which was derived from a fatty alcohol mixture consisting essentially of C₁₆-C₁₈ fatty alcohols. The non-ionic Component consisted of a fatty alcohol polyethylene glycol n-butyl ether based on an adduct of 5 moles of ethylene oxide with a fatty alcohol mixture of chain length C₁₂ to C₁₈. The weight ratio of anionic component to nonionic component was 6: 4. The total dosage of the collector mixture was 350 g / t.

The flotation was carried out in a laboratory flotation machine from Denver Equipment (model D 1 with 1 l cells). The cloud density was 500 g / l.

Water glass with a dosage of 1,000 g / t was used as the pusher. The flotation was carried out at a pH of approx. 9, which resulted from the addition of water glass. The flotation was carried out at room temperature with a pre-flotation stage and a post-cleaning stage, i.e. carried out in two stages. The conditioning time for collectors and pushers was 5 minutes each. The flotation time was 6 minutes. Conditioning and flotation were carried out at a stirring speed of 1200 rpm.

The results of the flotation are shown in Table 6.

Comparative Example 9

The same flotation task as in Example 7 was used.

The sodium alkyl sulfate described in Example 7 was used alone as a collector in a total dosage of 450 g / t. The flotation of the barite ore was otherwise carried out as described in Example 7. The results of the flotation are shown in Table 6. Table 6 Flotation of barite example Total dosage (g / t) BaSO₄ output (%) Concentrate content BaSO₄ (%) Example 7 350 98 91.6 Comparative Example 9 450 97 91.3

The flotation results in Table 6 show that when the collector mixture according to the invention is used with a significantly reduced dosage, a BaSO₄ output as high as with a predetermined amount of the sodium alkyl sulfate collector alone can be achieved.

Example 8

The flotation task consisted of an apatite ore, which had the following composition with regard to the main components: Magnetite 39% Apatite 18% Carbonates 11% Phlogopid 14% Olivine 9%.

The flotation task had the following grain size distribution: <25 µm 18% 25-100 µm 34% 100-200 µm 43% 200 µm 5%.

The collector mixture according to the invention used contained an acyl lactylate based on technical oleic acid as the anion-active component. The nonionic component consisted of an adduct of 5 moles of ethylene oxide with one mole of a fatty alcohol mixture of chain length C₁₂ to C₁₈. The weight ratio of anionic component to nonionic component was 7: 3. The total dosage of the collector mixture was 730 g / t.

The flotation was carried out in a laboratory flotation machine from Denver Equipment (model D 1 with a 1.2 l cell) at about 20 ° C. Hard water with 945 ppm Ca²⁺ and 1 700 ppm Mg²⁺ was used to produce the slurry. After the ore had been slurried in the flotation cell, the magnetite was removed with a hand magnet, washed and the wash water returned to the cell. The cloud density was 500 g / l. Water glass in an amount of 2,000 g / t was used as the pusher. The pH of the slurry was adjusted to 11. The flotation was carried out at a stirring speed of the mixing device of 1,500 rpm. The flotation time was 6 minutes. After the pre-flotation (rougher flotation), the pre-concentrate was cleaned twice.

The results of the flotation are shown in Table 7.

Comparative Example 10

The same flotation task as in Example 8 was used.

The acyl lactylate described in Example 8 was used alone and in a total dosage of 900 g / t as a collector. The flotation was carried out under the same conditions as in Example 8. The results of the flotation test are shown in Table 7. Table 7 Apatite flotation example Total dosage (g / t) P₂O₅ output (%) Concentrate content P₂O₅ (%) Example 8 730 80 22.3 Comparative Example 10 900 83 17.6

The flotation results shown in Table 7 show that the collector combination according to the invention according to Example 8 - in comparison to the conventional collector of Comparative Example 10 - enables a considerable reduction in the collector dosage without reducing the P₂O₅ output, the P₂O₅ content in the flotation product being further improved .

Claims (11)

1. The use of mixtures of

   a) at least one alkyl or alkenyl polyethylene glycol ether end-capped by hydrophobic groups and

   b) at least one anionic surfactant

   as collectors in the flotation of non-sulfidic ores.
2. The use claimed in claim 1, characterized in that at least one alkyl or alkenyl polyethylene glycol ether corresponding to formula I
   
   
   
           R¹ - O - (CH₂CH₂O)_n - R²   I
   
   
   
   in which R¹ is a linear or branched alkyl or alkenyl radical containing 8 to 22 carbon atoms, R² is a linear or branched alkyl radical containing 1 to 8 carbon atoms or a benzyl radical and n is a number of 1 to 30,
   is used as component a).
3. The use claimed in claim 2, characterized in that, in formula I, R¹ is an alkyl or alkenyl radical containing 12 to 18 carbon atoms.
4. The use claimed in claims 2 and 3, characterized in that, in formula I, n is a number of 2 to 15.
5. The use claimed in claims 2 to 4, characterized in that, in formula I, R² is an n-butyl radical.
6. The use claimed in claims 1 to 5, characterized in that at least one anionic surfactant from the group consisting of fatty acids, alkyl sulfates, alkyl ether sulfates, alkyl sulfosuccinates, alkyl sulfosuccinamides, alkyl benzene sulfonates, alkyl sulfonates, petroleum sulfonates, acyl lactylates, alkyl phosphates and alkyl ether phosphates is used as component b).
7. The use claimed in claims 1 to 6, characterized in that the ratio by weight of component a) to component b) is in the range from 1:20 to 3:1 and preferably in the range from 1:10 to 1:1.
8. The use claimed in claims 1 to 7, characterized in that the mixtures of a) and b) are used in quantities of 50 to 2,000 g and preferably in quantities of 100 to 1,500 g per tonne crude ore.
9. A process for the separation of non-sulfidic minerals from an ore by flotation in which ground ore is mixed with water to form a suspension, air is introduced into the suspension in the presence of a collector system and the forth formed is separated off together with the mineral present therein, characterized in that mixtures of

   a) at least one alkyl or alkenyl polyethylene glycol ether end-capped by hydrophobic groups and

   b) at least one anionic surfactant

   are used as collectors.
10. A process as claimed in claim 9, characterized in that the mixtures of a) and b) are used in quantities of 50 to 2,000 g per tonne crude ore.
11. A process as claimed in claims 9 and 10, characterized in that scheelite, baryta, apatite or iron ore is used as the ore.