Flotation process for silicate-containing iron ores

Abstract

The present invention relates to a process for producing a concentrate enriched in iron mineral content from an ore comprising iron minerals and silicates by reverse flotation, said process comprising the step of adding a first amine to an aqueous slurry of said ore prepared and optionally one or more flotation aids to obtain an aqueous mixture, wherein the first amine (A) is a compound of formula I, a salt of a protonated compound of formula I and a first anion or a mixture thereof. A second amine can be further added, which is a compound of formula II, a salt of a protonated compound of formula II and a second anion or a mixture thereof. Furthermore, specific compositions of the first amine (A) and the second amine (B) are described for use as a flotation collector.

Description

Technical Field

[0001] This invention relates to a method for producing a concentrate rich in iron minerals from ores containing iron minerals and silicates by reverse flotation using a first amine, particularly a mixture of a first amine and a second amine. Another embodiment is the use of a first amine as a flotation collector, particularly the use of a mixture of a first amine and a second amine as a flotation collector, and compositions of the first amine and the first amine as flotation collectors. Background Technology

[0002] Typical iron ore beneficiation processes require a flotation stage to remove silica (SiO2) from valuable iron minerals (such as oxides like hematite or magnetite) to obtain high-grade iron mineral concentrate. High-grade iron mineral concentrate can be used to manufacture high-quality steel. Removing SiO2 from various ores using froth flotation combined with hydrophobic amines is a well-known method. Negatively charged silicate particles can be hydrophobized using suitable amines. Injecting air into the flotation cell causes the formation of hydrophobic bubbles, which transport the hydrophobic silicate particles to the top of the cell. The resulting froth, containing the hydrophobic silicate particles, can be stabilized using suitable chemicals used as froth modifiers. Finally, the froth is removed from the top, leaving the enriched minerals at the bottom of the flotation cell.

[0003] GB 578695 relates to mineral beneficiation and a class of reagents for the selective separation of acidic minerals from other ore components. Reagents used in froth flotation are represented by compounds or salts of one of the following general formulas:

[0004]

[0005] Where y is an integer from 2 to 12, R is hydrogen or alkyl, R 1 R is an alkyl group having 8-30 carbon atoms or a carboxylic acid acyl group having 8-32 carbon atoms. 2 R is hydrogen or an alkyl or hydroxyalkyl ester or aralkyl group having 8-30 carbon atoms. 3 R is a carboxylic acid acyl group having 8 to no more than 32 carbon atoms. 4 It can be alkyl, hydroxyalkyl, hydroxyalkyl ester, or aralkyl. Test 2 discloses the flotation of phosphate rocks using N-lauryl ethylenediamine hydrobromide and pine oil. A method for processing iron ore to remove silica is proposed.

[0006] DE 1173041 relates to the flotation of oxidized minerals using aliphatic amines as collectors, said aliphatic amines being alone branched aliphatic primary amines having at least 6 carbon atoms and their water-soluble or oil-soluble salts, or being floated together with conventional collectors, foaming agents, or conditioning agents. Example 1A discloses the flotation of zinc carbonate and / or zinc phosphate using 2-ethylhexylamine acetate and sodium sulfide. Example 3 discloses the flotation of zinc carbonate and / or zinc silicate, wherein a mixture of 2-ethylhexylamine acetate and 2-ethylhexylamine, ethoxylated fatty alcohol as an emulsifier, and sodium sulfide are used.

[0007] EP 0174866 relates to collectors and a method for recovering raw material from metal ores by subjecting them in the form of an aqueous slurry to a froth flotation process in the presence of a collector, wherein the collector comprises a compound corresponding to the following formula.

[0008]

[0009] Where R is -CH2-, -CH(OH)-, -CO-, or a combination thereof, and n is an integer from 1 to 6 or -(R). n -for-(CH2) m -C≡, where m is an integer from 0 to 6, R 1 and each R 2 Independently for C 1-22 A C group may be substituted with one or more hydroxyl, amino, phosphono, alkoxy, imino, carbamoyl, carbonyl, thiocarbonyl, cyano, carboxyl, alkylthio, alkyloxy, alkylamino, or alkylimino groups. 1-22 Hydrocarbon-based, but with certain conditions. Example 1 discloses froth flotation of chalcopyrite copper sulfide ore, wherein N',N'-dibutylethane-1,2-diamine, N',N'-diethylethane-1,2-diamine, or N',N'-dihexylethane-1,3-diamine and Dowfoam 250 are used in particular as frothing agents. Example 4 discloses froth flotation of chalcopyrite copper sulfide ore, wherein N',N'-dibutylethane-1,2-diamine and Dowfoam are used in particular as frothing agents. Example 6 discloses froth flotation of nickel / cobalt ore, wherein N',N'-dibutylethane-1,2-diamine and frothing agents, such as triethoxybutane, are used in particular.

[0010] US2015-0096925 relates to collector compositions and methods for their preparation and use in purifying one or more crude materials. The collector composition may comprise one or more amide amines having the formula shown below:

[0011]

[0012] and one or more having the formula R 6-NH2 amines, wherein the weight ratio of the amide amine to the amine can be from about 99:1 to about 1:99. In Example 1, coconut oil fatty acid diethylenetriamine amide amine neutralized with glacial acetic acid was used in reverse flotation of phosphate ore to remove silica at neutral pH. In Example 2, coconut oil fatty acid diethylenetriamine amide amine neutralized with glacial acetic acid was used in reverse flotation of phosphate ore to remove silica at neutral pH. In Example 3, tall oil fatty acid diethylenetriamine neutralized with glacial acetic acid was used in reverse flotation of phosphate ore to remove silica at neutral pH. Other amide amines used similarly are lauric acid diethylenetriamine amide amine and rosin acid tetraethylenepentamine amide amine. Some embodiments also provide combinations of amide amines with amines, such as ether amines consisting of 95% by weight of 3-(8-methylnonoxy)prop-1-amine and 3% by weight of 8-methylnon-1-ol (e.g., cocoylamine or, for example, dodecylamine).

[0013] F. Nakhaei et al. disclosed in Miner. Process. Extr. Metall. Rev. (2017) the types of amine collectors commonly used in iron flotation selection, including aliphatic diamines.

[0014] US 3817972, EP 0174866, GB 578695 and US 4797202 also disclose amine derivatives for flotation; however, none of those disclosed are the type of amine collector for flotation of the present invention.

[0015] Although US2020 / 172767 discloses a dispersion composition comprising a mixture of about 50:50 n-hexylamine and N,N-diethyl-1,3-diaminopropane, and additionally comprising terpineol and silver particles, the composition is intended for use as a conductive adhesive composition and is therefore unsuitable for the purposes of this invention.

[0016] There is still a need to improve reverse flotation methods for ores containing both iron minerals and silicates, especially given the declining quality of the ores. Due to the higher SiO2 content in the ores, selective removal of silicates is more difficult compared to ores with lower SiO2 content in the past. On the one hand, iron mineral loss during flotation should be avoided, i.e., high recovery rates; on the other hand, the SiO2 content in concentrates rich in iron minerals should be reduced to low levels, i.e., selectivity. Low SiO2 content is particularly desirable for direct reduction processes using concentrates. Typically, mines, as ore processing sites, set a maximum level of residual SiO2 content allowed to remain in the concentrate at the end of the flotation process. This could be, for example, 2.5% by weight, especially 2.0% by weight. The goal is usually to at least reach this maximum silica level without significant loss of any iron mineral content. A combination of better recovery rates and comparable or better selectivity can reduce iron mineral loss in tailings and bring economic benefits. Summary of the Invention

[0017] The object of this invention is to provide a method for producing iron-rich concentrates, characterized by high iron mineral recovery and low SiO2 content from the ore used. Furthermore, attractively, the collectors used allow for the reduction or even elimination of specific flotation aids. Simultaneously, it is advantageous that the materials used in this method can be economically manufactured in a chemically relatively pure and therefore homogeneous form, for example, because fewer side reactions are possible. The chemically relatively pure materials can be fine-tuned for specific ores by combining them with other materials, particularly other collector aids.

[0018] According to the present invention, this objective is achieved by a method for producing a concentrate rich in iron minerals from an ore containing iron minerals and silicates by reverse flotation, the method comprising the steps of: (c) adding a first amine to an aqueous slurry of the prepared ore and optionally one or more flotation aids to obtain an aqueous mixture.

[0019] Its characteristic is that the first amine is

[0020] (A) A compound of formula I, a protonated compound of formula I, and a salt of the first anion, or a mixture thereof:

[0021]

[0022] Where R 1 and R 2 They are independently methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl, hexyl, heptyl, or 2-methylhexyl.

[0023] Preferably, a method for producing a concentrate rich in iron minerals from an ore containing iron minerals and silicates includes the following steps:

[0024] (a) Provide ore containing iron minerals and silicates,

[0025] (b) Aqueous slurry is prepared from the provided ore by adding water and optionally one or more flotation aids.

[0026] (c) Adding the first amine to the prepared ore and optionally one or more flotation aids containing...

[0027] In water-based slurry, an aqueous mixture is obtained.

[0028] The first amine is characterized by:

[0029] (A) A compound of formula I, a protonated compound of formula I, and a salt of the first anion, or a mixture thereof:

[0030]

[0031] Where R 1 and R 2 Each of the following is independently methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl

[0032] hexyl, heptyl, or 2-methylhexyl;

[0033] (d) Aerating the aqueous mixture in a flotation cell to produce silicate-rich foam, and extracting the foam from the flotation vessel.

[0034] Remove the foam generated in the selection tank.

[0035] (e) Obtaining a concentrate rich in iron minerals from the flotation cell.

[0036] Steps (a), (b), (c), (d), and (e) describe reverse flotation in more detail.

[0037] Preferably, a second amine is further added in step (c), which is:

[0038] (B) Compounds of Formula II, protonated compounds of Formula II, salts of the second anion, or mixtures thereof:

[0039]

[0040] Where R 3 For branched or linear C5-C 17 Alkyl, branched, or straight-chain C5-C 17 Alkenyl group.

[0041] The ore, containing iron minerals and silicates (SiO2), originates from, for example, magmatic or sedimentary deposits. Step (a) of providing the ore produces the provided ore. The step of providing the ore includes, for example, crushing and / or grinding the ore. In the case of ore from magmatic deposits, the step of providing the ore includes, for example, crushing and grinding the ore. In the case of ore from sedimentary deposits, the step of providing the ore includes, for example, crushing the ore, particularly crushing and wet grinding the ore. The ground and / or crushed ore is in granular form. In step (a) of providing the ore, the magnetic portion of the ore can be removed by magnetic treatment, preferably after the ore has been ground and / or crushed and is in granular form. The reference to ore weight or ore weight parts herein refers to dry ore. Preferably, step (a) of providing the ore produces the provided ore in granular form. Preferably, the ore provided is in granular form, with a particle size that allows 60-100% by weight of particles, based on the total weight of the ore provided, to pass through a 100 μm steel mesh sieve, as measured by a standard dry sieve. Preferably, step (a) of providing the ore produces the ore provided in granular form, with more than 90% by weight of particles having a particle size of 150 μm or smaller. Very preferably, step (a) of providing the ore produces the ore provided in granular form, with more than 90% by weight of particles having a particle size of 150 μm or smaller, and more than 80% by weight of particles having a particle size of 106 μm or smaller. In particular, step (a) of providing the ore produces the ore provided in granular form, with more than 90% by weight of particles having a particle size of 150 μm or smaller, more than 80% by weight of particles having a particle size of 106 μm or smaller, and more than 30% by weight of particles having a particle size of 38 μm or smaller. In particular, step (a) of providing the ore produces the provided ore in particulate form, wherein more than 92% by weight of the particulates have a particle size of 150 μm or less, more than 82% by weight of the particulates have a particle size of 106 μm or less, and more than 35% by weight of the particulates have a particle size of 38 μm or less.

[0042] The ore preferably contains 20-65% by weight of iron atoms, based on the total weight of the ore. The weight content of iron atoms (Fe atoms) is similar to the weight content of iron. The iron atom content is determined, for example, by WDXRF. The ore very preferably contains 25-55% by weight, particularly 30-50% by weight, and very particularly 35-47% by weight of iron atoms. The iron minerals are, for example, iron oxides. Typical iron oxides are hematite (Fe2O3 with 69.9% by weight of iron), magnetite (Fe3O4 with 72.4% by weight of iron), goethite (Fe(O)OH with 62.9% by weight of iron) or mixtures thereof. Preferably, the iron minerals consist of less than 10% by weight of iron sulfides, based on the total weight of all iron minerals in the ore. Very preferably, all iron minerals in the ore are non-sulfide iron minerals. The iron minerals in the ore preferably consist of 90-100% by weight of iron oxides, based on the total weight of all iron minerals in the ore. Very preferably, the iron minerals in the ore consist of at least 97% to 100% iron oxides, particularly 99% to 100% iron oxides.

[0043] The ore preferably contains 20-65 wt% iron atoms and 20-70 wt% silicates calculated as SiO2, very preferably 25-55 wt% iron atoms and 25-55 wt% silicates calculated as SiO2, particularly 30-50 wt% iron atoms and 30-45 wt% silicates calculated as SiO2, and very particularly 35-47 wt% silicon atoms and 32-43 wt% silicates calculated as SiO2.

[0044] Typical ores contain 40-70 wt% hematite and 30-50 wt% silicates (calculated as SiO2), particularly 45-65 wt% hematite and 30-45 wt% silicates (calculated as SiO2). Preferably, more than 50 wt% of the iron minerals in the ore are iron oxides, namely hematite. Very preferably, 70-100 wt% of the iron minerals in the ore are iron oxides, namely hematite.

[0045] The preferred method is one in which the ore contains 20-55% by weight of iron atoms based on the weight of the ore.

[0046] Compounds of Formula I and Formula II are used as collectors in this method for foam flotation.

[0047] The first amine (A) further includes a mixture of two or more compounds of formula I. Preferably, R 1 and R 2 Each of the following is independently methyl, ethyl, propyl, 1-methylethyl, butyl, or pentyl. Most preferably, R 1 and R 2Each is independently methyl, ethyl, propyl, or 1-methylethyl. In particular, R 1 and R 2 Each can be independently methyl, propyl, or 1-methylethyl. Very specifically, R 1 and R 2 Each is independently methyl or propyl. Preferably, R 1 and R 2 Same. Very preferably, R 1 and R 2 The same, and is methyl, ethyl, propyl, 1-methylethyl, butyl, or pentyl. Specifically, R 1 and R 2 The same, and is methyl, ethyl, propyl, or 1-methylethyl. Very specifically, R 1 and R 2 The same, and is methyl, propyl, or 1-methylethyl. Specifically, R 1 and R 2 Same, and either methyl or propyl. Very specifically, R 1 and R 2 It is propyl.

[0048] Where R 1 and R 2 The propyl compound of formula I is N',N'-dibutylpropane-1,3-diamine, as shown below:

[0049]

[0050] Where R 1 and R 2 The methyl compound of formula I is N',N'-diethylpropane-1,3-diamine, as shown below:

[0051]

[0052] Where R 1 and R 2 The compound of formula I with ethyl groups is N',N'-dipropylpropane-1,3-diamine, as shown below:

[0053]

[0054] Where R 1 and R 2 The compound of formula I, which is 1-methylethyl, is N',N'-diisobutylpropane-1,3-diamine, as shown below:

[0055]

[0056] Where R 1 and R 2The butyl compound of formula I is N',N'-dipentylpropane-1,3-diamine, as shown below:

[0057]

[0058] Where R 1 and R 2 The pentyl compound of formula I is N',N'-dihexylpropane-1,3-diamine, as shown below:

[0059]

[0060] Where R 1 and R 2 The hexyl compound of formula I is N',N'-diheptylpropane-1,3-diamine, as shown below:

[0061]

[0062] Where R 1 and R 2 The heptyl compound of formula I is N',N'-dioctylpropane-1,3-diamine, as shown below:

[0063]

[0064] Where R 1 and R 2 The compound of formula I with 2-methylhexyl is N',N'-bis(3-methylheptyl)propane-1,3-diamine, as shown below:

[0065]

[0066] Where R 1 It is propyl and R 2 The compound of formula I with methyl is N'-butyl-N'-ethylpropane-1,3-diamine, as shown below:

[0067]

[0068] The preferred one is R. 1 and R 2 A method in which each of the following is independently methyl, ethyl, propyl, 1-methylethyl, butyl, or pentyl.

[0069] The preferred one is R. 1 and R 2 The same method.

[0070] The preferred one is R. 1 and R 2 The method for propyl groups.

[0071] The second amine (A) also includes a mixture of two or more compounds of formula II. 3 Examples include pentyl, hexyl, heptyl, 1-ethylpentyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, isoundecyl, dodecyl, isododecyl, tridecyl, isotridecyl, tetradecyl, isotetradecyl, pentadecyl, isopentadecanyl, hexadecyl, isohexadecyl, heptadecanyl, isohexadecanyl, dec-9-enyl, or (Z)-heptadec-8-enyl. Preferably, R 3 For branched or linear C5-C 12 Alkyl, or branched or straight-chain C 10 -C 17 Alkenyl group. Most preferably, R 3 For branched or linear C5-C 12 Alkyl, or straight-chain C 17 Alkenyl groups. Very specifically, R 3 For branched or linear C5-C 12 Alkyl group. Specifically, R 3 It is a branched or straight-chain C5-C9 alkyl group. Very specifically, R 3 It is a branched or straight-chain C6-C8 alkyl group. More specifically, R 3 It is a branched C7 alkyl group. Most notably, R 3 It is 1-ethylpentyl.

[0072] Where R 3 The compound of formula II that is 1-ethylpentyl is 2-ethylhexyl-1-amine, as shown below:

[0073]

[0074] Where R 3 Compounds of formula II with an pentyl group are hexyl-1-amines, as shown below:

[0075]

[0076] Where R 3 Compounds of formula II that are heptadecanyl are octadecane-1-amines, as shown below:

[0077]

[0078] Where R 3 The compound of formula II, which is (Z)-heptadec-8-enyl, is (Z)-octadec-9-en-1-amine, as shown below:

[0079]

[0080] The preferred one is R. 3 For branched or straight-chain C7-C12 Alkyl method.

[0081] The preferred one is R. 3 The method for 1-ethylpentyl.

[0082] The preferred one is R. 1 and R 2 It is propyl and R 3 The method for 1-ethylpentyl.

[0083] The first anion is the deprotonated form of acid A'(-H)p, where -H represents an acid proton and p represents the number of acid protons in acid A'(-H)p. Depending on the acid strength of acid A'(-H)p, some acid protons of acid A'(-H)p may not be deprotonated in the salt of the compound of formula I.

[0084] Protonated compounds of formula I and salts of the first anion are also represented by formulas I-t1-1+, I-t2-1+, or I-t1-2+:

[0085]

[0086] Where A' represents the first anion, y is an integer of at least 1, and y represents the negative charge of the anion. y is not higher than p, where p is the acid proton number of acid A(-H)p. Preferably, the anion is a deprotonated acid A(-H)p, where p is 1, 2, or 3. For p = 1, y is 1; for p = 2, y is 1 or 2; and for p = 3, y is 1, 2, or 3. Formulas I-t1-1+ and I-t2-1+ describe the tautomerism of the same salt.

[0087] The first anion is, for example, C1-C. 18 Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, hydrofluorosilicate, fluorosilicate, or mixtures thereof. C1-C 18 The carboxyl group is, for example, an aliphatic or olefinic carboxyl group, preferably an aliphatic C1-C group. 13 Carboxylate ions, particularly aliphatic C1-C6 carboxylate ions, especially formate, acetate, or propionate ions. Sulfonate ions are, for example, methanesulfonate, ethylsulfonate, propylsulfonate, or 1-methylethylsulfonate. Preferably, the sulfonate ion is an alkylsulfonate ion, particularly C1-C6 sulfonate ions, especially C1-C3 sulfonate ions, and very particularly methanesulfonate ions. C1-C6 sulfonate ions are preferred. 18 Carboxylate, fluoride, chloride, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, or nitrate. Aliphatic or olefinic C1-C ions are particularly preferred. 18 Carboxylate ions, particularly formate, acetate, or propionate ions, are preferred.

[0088] The preferred method is as follows, wherein the first anion is C1-C. 18 Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, hydrofluorosilicate, fluorosilicate, or mixtures thereof.

[0089] The second anion is the deprotonated form of acid A(-H)p, where -H represents an acid proton and p represents the number of acid protons in acid A(-H)p. Depending on the acid strength of acid A(-H)p, some acid protons of acid A(-H)p may not be deprotonated in the salt of the compound of formula II.

[0090] Protonated compounds of formula II and salts of the second anion are also represented by formula II-t1-1+:

[0091]

[0092] Where A” represents the second anion, y is an integer of at least 1, and y represents the negative charge of the anion. y is not higher than p, where p is the acid proton number of acid A””-H)p. Preferably, the anion is a deprotonated acid A””-H)p, where p is 1, 2, or 3. For p = 1, y is 1; for p = 2, y is 1 or 2; and for p = 3, y is 1, 2, or 3.

[0093] The second anion is, for example, C1-C. 18 Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, hydrofluorosilicate, fluorosilicate, or mixtures thereof. C1-C 18 The carboxyl group is, for example, an aliphatic or olefinic carboxyl group, preferably an aliphatic C1-C group. 13 Carboxylate ions, particularly aliphatic C1-C6 carboxylate ions, especially formate, acetate, or propionate ions. Sulfonate ions, for example, are methanesulfonate, ethylsulfonate, propylsulfonate, or 1-methylethylsulfonate. Preferably, the sulfonate ion is an alkylsulfonate ion, particularly C1-C6 sulfonate ions, especially C1-C3 sulfonate ions, and very particularly methanesulfonate ions. C1-C6 sulfonate ions are preferred. 18 Carboxylate, fluoride, chloride, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, or nitrate. Aliphatic or olefinic C1-C ions are particularly preferred. 18 Carboxylate ions, with formate, acetate or propionate ions being particularly preferred.

[0094] The preferred method is as follows, wherein the second anion is C1-C. 18Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, hydrofluorosilicate or fluorosilicate.

[0095] Preferably, the first anion and the second anion are independently C1-C. 18 Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, hydrofluorosilicate or fluorosilicate.

[0096] Preferably, the first anion and the second anion are the same. This also includes the case where, in the case of a mixture of specific anions, the mixture is identical.

[0097] In step c), in the presence of the second amine (B), the weight ratio of the first amine (A) to the second amine is preferably 0.1-10. A weight ratio of 0.1 corresponds to 1 part by weight of the first amine (A) and 10 parts by weight of the second amine (B). A weight ratio of 10 corresponds to 1 part by weight of the first amine (A) and 0.1 parts by weight of the second amine (B). Very preferably, the weight ratio of the first amine (A) to the second amine (B) is 0.15-5, particularly 0.18-2, very particularly 0.2-1, particularly 0.25-0.7, and very particularly 0.3-0.5.

[0098] The preferred method is the one in which, in step c), the weight ratio of the first amine (A) to the second amine (B) is 0.1-10.

[0099] The preferred method is the one in which, in step c), the weight ratio of the first amine (A) to the second amine (B) is 0.2-1.

[0100] The primary amine (A) is preferably added at a rate of 10-500 g per ton of ore. In other words, the primary amine (B) is added at a rate of 10-500 g per ton of ore. This amount is very preferably 30-300 g per ton of ore, particularly preferably 40-250 g per ton of ore, especially 50-200 g per ton of ore, and very particularly 60-160 g per ton of ore. The total amount of the primary amine (A) can be added all at once or in batches.

[0101] The preferred method is as follows, wherein the first amine (A) is added at a rate of 10-500g per ton of ore.

[0102] When a second amine (B) is further added, the first amine (A) and the second amine (B) are preferably added at a rate of 10-500 g per ton of ore. In other words, the sum of the weights of the first amine (A) and the second amine (B) is added at a rate of 10-500 g per ton of ore. This amount is very preferably 30-300 g per ton of ore, particularly preferably 40-250 g per ton of ore, especially 50-200 g per ton of ore, and very particularly 60-160 g per ton of ore. The total amount of the first amine (A) and the second amine (B) can be added all at once or in batches.

[0103] The preferred method is that the sum of the weights of the first amine (A) and the second amine (B) is added at a rate of 10-500g per ton of ore.

[0104] Preferably, the first amine and the second amine are added together in step (c) as a composition used as a flotation collector. The composition comprises:

[0105] (A) A first amine, which is a compound of formula I, a protonated compound of formula I, and a salt of the first anion or a mixture thereof.

[0106] Compounds, and

[0107] (B) A second amine, which is a compound of formula II, a protonated compound of formula II and a salt of the first anion or a mixture thereof.

[0108] Preferably, the sum of the weights of the first amine (A) and the second amine (B) in the composition is 50-100% by weight, based on the total weight of the composition. Very preferably, this range is 60-100% by weight, particularly 70-10% by weight, and very particularly 80-95% by weight.

[0109] In steps (c) and (d) of this method, the pH value is preferably adjusted to a specific pH range using a pH adjuster, typically to 8-12, particularly 9-11. The pH adjuster is usually a strong base, such as sodium hydroxide, potassium hydroxide, sodium carbonate, or potassium carbonate. Preferably, the pH value of the aqueous slurry is 8-12, particularly 9-11. Preferably, step (c), i.e., adding the first amine (A) and the second amine (B) to the aqueous slurry, is carried out at a pH value of 8-12, particularly 9-11. Preferably, the pH value of the aqueous mixture is 8-12, particularly 9-11. Preferably, step (d), i.e., aerating the aqueous mixture, is carried out at a pH value of 8-12, particularly 9-11. Preferably, step (e), i.e., obtaining a concentrate rich in iron minerals, is carried out at a pH value of 8-12, particularly 9-11. pH adjustment helps the ore, especially the ore particles, to exhibit the correct surface charge.

[0110] The preferred method is one in which the pH value of step (c) is 8-12.

[0111] The preferred method is one in which the pH value of steps (c) and (b) is 8-12.

[0112] The preferred method is one in which the pH value of steps (c) and (d) is 8-12.

[0113] The preferred method is one in which the pH value of steps (c), (b) and (d) is 8-12.

[0114] The preferred method is one in which the pH value of steps (c), (b), (d), and (e) is 8-12.

[0115] Flotation aids differ from compounds of formula I or II. Examples of flotation aids include depressants, foam modifiers, collector aids, or filler oils.

[0116] Inhibitors help prevent the flotation of ore components, which are undesirable frothy portions or generally contribute to selectivity in concentrate production methods. Inhibitors are, for example, hydrophilic polysaccharides, particularly starch or sodium silicate. Starch is, for example, natural or modified starch. Natural starch is, for example, starch from corn, wheat, oats, barley, rice, millet, potatoes, peas, cassava, or tapioca. Natural starch is preferably pregelatinized, i.e., heated in an aqueous solution to gelatinize the starch, or causticized, i.e., treated in an aqueous solution with a strong alkali such as NaOH, KOH, or Ca(OH)₂. Modified starch is degraded starch (which has a lower weight-average molecular weight relative to the original starch), chemically modified starch, or a combination of both. Starch degradation can be achieved, for example, by oxidation or treatment with acids, alkalis, or enzymes. Degradation typically results in an increase in oligosaccharide or dextrin content. Chemical modification functionalizes starch by covalently bonding chemical groups to it. Chemically modified starch can be obtained, for example, by esterification or etherification of starch. Esterification of starch with acids can be carried out, for example, with acid anhydrides or chloride ions of acids. The etherification of starch can be carried out, for example, using organic reagents containing reactive epoxy functional groups. Preferred is the inhibitor, which is starch, most preferably natural starch, especially pregelatinized or causticized starch, particularly causticized starch. The inhibitor is preferably added in an amount of 100-3000 g per ton of ore. This calculation is based on dry ore. This amount is most preferably 300-2200 g per ton of ore, particularly preferably 400-1500 g per ton of ore, especially 500-1100 g per ton of ore, and most particularly 550-800 g per ton of ore.

[0117] Foam modifiers help improve the efficiency of this production method by interfering with foam generation. Foam properties include, for example, foam height, foam volume, or foam stability, i.e., the time it takes for the foam to collapse after aeration stops. Examples of foam modifiers include pine oil, methyl isobutyl alcohol, and C6-C... 12Alcohols, particularly 2-ethylhexanol or hexanol, alcohol esters, especially mixtures containing 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, distillation residues from the carbonyl synthesis of 2-ethylhexanediol, terpineol, triethoxybutane, alkoxylated alcohols, particularly ethoxylated and / or propoxylated alcohols, polyethylene glycol or polypropylene glycol. Preferably, the method does not use alkoxylated alcohols, very preferably does not use alkolized alcohols, polyethylene glycol or propylene glycol, and especially does not use foam modifiers. It remains attractive that the method does not require the addition of foam modifiers.

[0118] The collector aid is a surface-active compound that differs from compounds of Formula I or Formula II. The collector aid can be cationic, nonionic, or anionic, preferably cationic or nonionic, and very preferably cationic. Cationic collector aids can be, for example, secondary or tertiary C9-C compounds different from those of Formula I. 18 Alkylamines, 2-(C9-C 18 (alkylamino)ethyl-1-amine, N'-(C9-C 18 Alkyl)propane-1,3-diamine, 3-(C9-C 18 alkoxypropyl-1-amine, N'-(3-(C9-C) 18 Alkoxypropylpropane-1,2-diamine. Nonionic co-collectors, for example, branched C9-C... 15 Alkyl alcohols, or branched C9-C ethoxylated with 2-4 moles of ethylene oxide. 15 Alkyl alcohols. When using a collector aid as a flotation aid, the collector aid can be added together with the first amine (A) and the second amine (B). In this case, this part of step (b) occurs simultaneously with step (c). Still attractively, this method does not require the addition of a collector aid.

[0119] The preferred method is to add one or more flotation aids in step (b), wherein one of the flotation aids is an inhibitor, a foam regulator, a collector aid, or a filler oil.

[0120] The preferred method is the addition of an inhibitor as a flotation aid, wherein the inhibitor is starch.

[0121] In the method of producing concentrate, conventional reverse flotation equipment can be used. Preferably, a first amine (A) and optional flotation aids (which are collector aids) are added to the aqueous slurry already in a flotation cell used for aeration of the mixture in step (d). Preferably, a first amine (A) and a second amine (B), along with optional flotation aids as collector aids, are added to the aqueous slurry already in a flotation cell used for aeration of the mixture in step (d).

[0122] After adding the first amine (A) to the aqueous slurry, it is preferable to retain the resulting aqueous mixture, particularly under agitation, for a conditioning period before aeration. This allows the first amine (A) and optional flotation aids (which are collectors) to condition the ore, particularly the ore particles, in the aqueous mixture. Similarly, after adding the first amine (A) and the second amine (B) to the aqueous slurry, it is preferable to retain the resulting aqueous mixture, particularly under agitation, for a conditioning period before aeration. This allows the first amine (A) and the second amine (B), along with optional flotation aids (which are collectors), to condition the ore, particularly the ore particles, in the aqueous mixture. The conditioning time is, for example, 1 minute or at most 10 or 15 minutes.

[0123] When aerating an aqueous mixture, air is typically injected into the bottom of the flotation cell. Bubbles form and rise to the surface, creating foam. Air can be injected continuously until no more foam forms. This may take 1 minute or at most 15 or 20 minutes. The foam is then removed.

[0124] To obtain a concentrate rich in iron minerals, aeration is usually stopped. The concentrate rich in iron minerals typically settles to the bottom of the flotation cell.

[0125] In some cases, it may be necessary to process iron-rich concentrates again in a similar manner. For example, repeat steps (c) and (d) (as step (dc)) before proceeding to step (e), followed by step (dd).

[0126] Based on the total weight of the iron-rich concentrate, the iron-rich concentrate preferably contains at least 60% by weight of iron atoms, very preferably at least 65% by weight. The weight of the iron atoms is similar to the weight of the iron content. Based on the total weight of the iron-rich concentrate, the iron-rich concentrate preferably contains less than 2.5% by weight of SiO2, very preferably less than 2.1% by weight, particularly preferably 2.0% by weight or less than 1.9% by weight of SiO2. Based on the total weight of the iron-rich concentrate, the iron-rich concentrate preferably contains at least 60% by weight of iron atoms and less than 2.5% by weight of SiO2, very preferably at least 65% by weight of Fe atoms and less than 2.1% by weight of SiO2.

[0127] The method for producing the concentrate is described above with the use of an added first amine (A), and preferably a combination of first amine (A) and first amine (B). These preferred embodiments are also applicable to other embodiments of the invention.

[0128] Another embodiment of the present invention is the use of a first amine (A) as a flotation collector for producing a concentrate rich in iron minerals from ores containing iron minerals and silicates by reverse flotation, characterized in that the first amine is:

[0129] (A) A compound of formula I, a protonated compound of formula I, and a salt of the first anion, or a mixture thereof.

[0130]

[0131] Where R 1 and R 2 They are independently methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl, hexyl, heptyl, or 2-methylhexyl.

[0132] Preferably, the use includes adding a first amine to an aqueous slurry of the prepared ore and optionally one or more flotation aids to obtain an aqueous mixture.

[0133] Preferred uses include the use of a combination of a first amine (A) and a second amine (B) as a flotation collector for the production of an iron-rich concentrate from ores containing iron minerals and silicates by reverse flotation, wherein the second amine is a compound of formula II, a protonated compound of formula II, a salt of a second anion, or a mixture thereof.

[0134]

[0135] Where R 3 For branched or linear C5-C 17 Alkyl, branched, or straight-chain C5-C 17 Alkenyl group.

[0136] Therefore, the first amine (A) and the second amine (B) are preferably used together as flotation collectors.

[0137] Preferably, the use includes adding a first amine and a second amine to an aqueous slurry of the prepared ore and optionally one or more flotation aids to obtain an aqueous mixture.

[0138] Another embodiment of the present invention is a composition used as a flotation collector, comprising: (A) a first amine, which is a compound of formula I, a protonated compound of formula I, and a salt of a first anion or thereof.

[0139] mixture:

[0140]

[0141] Where R 1 and R 2 Each of the following is independently methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl

[0142] (A) a compound of formula II, a protonated compound of formula II, or a salt of the first anion or thereof.

[0143] mixture:

[0144]

[0145] Where R 3 For branched or linear C5-C 17 Alkyl, branched, or straight-chain C5-C 17 Alkenyl,

[0146] The weight ratio of the first amine (A) to the second amine (B) is 0.2-1.

[0147] Preferably, the composition used as the flotation collector of the present invention is a water-soluble composition.

[0148] Preferably, the composition is used as a flotation collector, wherein the sum of the weights of the first amine (A) and the second amine (B) is 50-100% by weight based on the total weight of the composition. Detailed Implementation

[0149] The following embodiments further illustrate the invention but do not limit it. Unless otherwise stated, percentages are weight percentages.

[0150] A) Chemicals used

[0151] A-1: Flotigam EDA (RTM, Clariant Ltd), C9-C 12 Ether monoamine acetate

[0152] A-2: 2-Ethylhexyl-1-amine [CAS No. 104-75-6], neutralized with acetic acid at 50 mol% [acetate CAS No. 67785-97-1]

[0153] A-3: N',N'-dibutylpropane-1,3-diamine [CAS No. 102-83-0], neutralized with acetic acid at 50 mol%.

[0154] A-4: A mixture of 75% by weight A-2 and 25% by weight A-3

[0155] A-5: N',N'-dibutylethane-1,2-diamine [CAS No. 3529-07-7], neutralized with acetic acid at a concentration of 50 mol%.

[0156] A-6: 3-(N-Octylamino)propyl-1-amine [CAS No. 7173-57-1]

[0157] St-1: Causticized starch

[0158] Add 6g of corn starch and 52g of distilled water to a 600mL beaker. Add 2g of 50% NaOH aqueous solution and mix vigorously for 10 minutes until a gel appearance is obtained. Add 140g of distilled water to the mixture and homogenize with a magnetic stirrer for 5 minutes.

[0159] B) Selective Calculation

[0160] The selectivity for valuable minerals and gangue can be measured by separation efficiency (SE), which is defined as SE = R v -R G R v It is the recovery rate of valuable elements, R G This refers to the recovery rate of gangue, as described in Norman F. Schulz's paper "Separation Efficiency" presented at the Annual Meeting of the American Institute of Mining, Metallurgical and Petroleum Engineers, Washington, DC, 1969, Society of Mining Engineers of AIME, preprint No. 69-B-44 (available in digital form, e.g., www.911metallurgist.com / separation-efficiency / ). The same calculation can be performed using elemental analysis of concentrate and tailings fractions, and expressed as:

[0161]

[0162] in:

[0163] c: Atomic content of the required elements in the concentrate [wt%]

[0164] c m The atomic content [weight %] of the required elements in the selected minerals.

[0165] f: Atomic content [weight %] of the required elements in the feed.

[0166] t: Atomic content of the required element in the tailings [weight %].

[0167] The ideal separation efficiency is 100, but the actual value is lower than 100. The closer to 100, the better the separation and recovery of valuable elements.

[0168] In the case of ferroquartzite ore, the required element is iron (Fe), and the refined mineral is hematite (Fe₂O₃), with an iron atom content of 69.9%. The gangue in the ferroquartzite ore is mainly composed of quartz (SiO₂), determined by WDXRF as Si and recalculated as SiO₂ in the concentrate. For the calculation of separation efficiency, only the iron content of the fractions is used.

[0169] C) Flotation

[0170] C-1: Flotation of the first type of ferroic quartzite iron ore

[0171] The first type of iron quartzite (45.03 wt% Fe and 35.36 wt% SiO2) was ground to the particle size distribution shown in Table C-1-1, in which the iron was mainly contained in the form of hematite.

[0172] Table C-1-1: Particle size distribution of ground ferro-quartzite type iron ore

[0173] Size range [μm] >150 150-106 105-76 75-38 <38 Weight fraction [%) 6.4 10.1 18.8 16.8 47.9

[0174] 500 g of ground ferro-quartzite type iron ore and 400 mL of distilled water were placed in a 1.5 L flotation cell of a CDC flotation machine and stirred at 1000 rpm. The slurry was adjusted for 5 minutes with causticized starch solution St-1 (corresponding to 665 g of starch per ton of dry ore). The pH was raised to 10.2 using a 5 wt% NaOH aqueous solution. Subsequently, 7.5 g of a 1 wt% collector aqueous solution listed in Table C-1-2 (corresponding to 150 g per ton of dry ore) was added to the slurry and adjusted for 1 minute. After adjustment, 550 mL of distilled water was added, and the slurry was aerated at 1 L / min until the end of flotation (3 minutes). The froth fraction was collected and aeration was stopped. The water level was maintained throughout the flotation time. The remaining cell fraction (further described as concentrate) and the separated froth were dried in an oven at 100 °C, weighed, homogenized, and their Fe and Si contents were determined in a lithium borate molten bead matrix using WDXRF. The Si content was recorded as SiO2. The results are listed in Table C-1-2.

[0175] Table C-1-2:

[0176]

[0177] footnote:

[0178] a) Comparison.

[0179] b) According to the present invention.

[0180] c) Fe recovery rate refers to the ratio of the total amount of Fe atoms in the cell fraction to the total amount of Fe atoms in the ore used as raw material.

[0181] d) Fe concentrate grade refers to the Fe atomic content in the fraction.

[0182] e) Si recovery rate refers to the ratio of the total number of Si atoms in the cell fraction to the total number of Si atoms in the ore used as raw material.

[0183] f) SiO2 concentrate grade refers to the SiO2 content in the trough fraction.

[0184] The results in Table C-1-2 show that Example C-1-4, using two collectors, exhibits a significantly improved Fe recovery rate, far exceeding the expected values ​​for Fe recovery rates with a single collector in Examples C-1-2 and C-1-3. Furthermore, the SiO2 content remains at a low level, within the expected range for both single collectors. This is significant given the substantial improvement in iron recovery and leads to optimal separation efficiency. Example C-1-3, using a single collector, also shows significant separation efficiency.

[0185] C-2: Flotation of the second type of ferroquartzite iron ore

[0186] The second type of iron quartzite-type iron ore (38.4 wt% Fe and 41.0 wt% SiO2) was ground to the particle size distribution shown in Table C-2-1, in which the iron was mainly contained in the form of hematite.

[0187] Table C-2-1: Particle size distribution of ground ferro-quartzite type iron ore

[0188] Size range [μm] >400 400-213 212-151 150-107 106-64 63-38 <38 Weight fraction [%) 0.7 0.3 3.9 8.1 21.2 25.0 40.8

[0189] 500g of ground ferro-quartzite type iron ore and 400mL of tap water from Ludwigshafen were placed in a 1.2L flotation cell of a Denver D12 flotation machine and stirred at 1200rpm. The slurry was adjusted for 5 minutes with causticized starch solution St-1 (corresponding to 560g of starch per ton of dry ore). The pH was raised to 10.5 using a 10% by weight NaOH aqueous solution. Subsequently, 3.75mL of a 1% by weight collector aqueous solution listed in Table C-2-2 (corresponding to 75g per ton of dry ore) was added to the slurry and adjusted for 3 minutes. After adjustment, 250mL of tap water from Ludwigshafen was added, and the slurry was aerated at 100L / min until the end of flotation (3 minutes). The froth fraction was collected and aeration was stopped. The water level was maintained throughout the flotation time. The pH was reset to 10.5 using a 10% by weight NaOH aqueous solution. 1.25 mL of the above collector solution (corresponding to 25 g collector per ton of initial dry ore) was added to the slurry. Aeration was then carried out at 100 L / h, which resulted in the flotation of an additional frothy phase, which was collected in a fresh tray.

[0190] The remaining fraction (concentrate) and the separated froth component were dried in an oven at 70°C, weighed, homogenized, and their Fe and Si contents were determined using WDXRF in a lithium borate molten bead matrix. The Si content was recorded as SiO2. The results are listed in Table C-2-2.

[0191] Table C-2-2:

[0192]

[0193] footnote:

[0194] a) Comparison.

[0195] b) According to the present invention.

[0196] c) Fe recovery rate refers to the ratio of the total amount of Fe atoms in the cell fraction to the total amount of Fe atoms in the ore used as raw material.

[0197] d) Fe concentrate grade refers to the Fe atomic content in the fraction.

[0198] e) Si recovery rate refers to the ratio of the total number of Si atoms in the cell fraction to the total number of Si atoms in the ore used as raw material.

[0199] f) SiO2 concentrate grade refers to the SiO2 content in the trough fraction.

[0200] The results in Table C-2-2 show that Example C-2-4, using two collectors, exhibits improved Fe recovery, which is higher than the expected values ​​for iron recovery from the single collectors in Examples C-2-2 and C-2-3. Furthermore, the SiO2 content remains at a low level, which is not expected from the single collector A-2 in Example C-2-3. Given the improved iron recovery, this is significant and leads to optimal separation efficiency. Example C-2-3, using a single collector, still shows significant separation efficiency. C-3: Flotation of a third type of ferroquartzite iron ore.

[0201] The mixture contains a small amount of muscovite (KAl2(OH,F)2[AlSi3O) 10 ]) and kaolinite (Al4[(OH)8[Si4O) 10 The third type of iron quartzite (40.3 wt% Fe and 40.6 wt% SiO2) was ground to the particle size distribution shown in Table C-3-1, in which the iron was mainly contained in the form of hematite.

[0202] Table C-3-1: Particle size distribution of ground ferroquartzite-type iron ore

[0203] Size range [μm] >400 400-213 212-151 150-107 106-64 63-38 <38 Weight fraction [%) <0.1 1.8 6.1 9.2 20.7 22.0 40.1

[0204] 500g of ground ore and 400mL of Ludwigshafen tap water were placed in a 1.2L clear plexiglass flotation cell in a Denver D12 flotation machine and stirred at 1200rpm. The slurry was adjusted for 5 minutes with causticized starch solution St-1 (corresponding to 560g of starch per ton of dry ore). The pH was raised to 9.8 using a 10% by weight NaOH aqueous solution. Subsequently, 3.75mL of a 1% by weight collector aqueous solution listed in Table C-3-2 (corresponding to 75g of dry ore) was added to the slurry and adjusted for 3 minutes. After adjustment, 250mL of Ludwigshafen tap water was added, and the slurry was aerated at 100L / min until the end of flotation (3 minutes). The froth fraction was collected in a tray. The pH was monitored and maintained at 9.4-9.7 by adding 10% by weight NaOH aqueous solution as needed. The water level was kept approximately constant throughout the flotation time. After foam formation, the pH was reset to 9.8 using a 10% by weight NaOH aqueous solution. 1.25 mL of a 1% by weight collector aqueous solution (corresponding to 25 g per ton of initial dry ore) listed in Table C-3-2 was added to the slurry and adjusted at 1200 rpm for 1 minute. The foam was then aerated at 100 L / h until flotation was complete (approximately 2.5 minutes). Aeration was stopped. The remaining cell fraction (concentrate) and the combined foam fraction were dried in an oven at 70°C, weighed, homogenized, and their Fe and Si contents were determined using WDXRF in a lithium borate molten bead matrix. The Si content was recorded as SiO2. The results are listed in Table C-3-2.

[0205] Table C-3-2:

[0206]

[0207] footnote:

[0208] a) Comparison.

[0209] b) According to the present invention.

[0210] c) Fe recovery rate refers to the ratio of the total amount of Fe atoms in the cell fraction to the total amount of Fe atoms in the ore used as raw material.

[0211] d) Fe concentrate grade refers to the Fe atomic content in the fraction.

[0212] e) Si recovery rate refers to the ratio of the total number of Si atoms in the cell fraction to the total number of Si atoms in the ore used as raw material.

[0213] f) SiO2 concentrate grade refers to the SiO2 content in the trough fraction.

[0214] The results in Table C-3-2 show that Example C-2-1, using a single collector A-3, exhibited improved iron recovery compared to Example C-3-2, which used a single collector A-5. Furthermore, the SiO2 content was lower. Both contribute to better separation efficiency. This is significant given that the structural difference between A-3 and A-5 lies solely in the additional CH2 unit in A-3, i.e., A-3 is a propylene-1,3-diamine derivative while A-5 is an ethylene-1,2-diamine derivative.

[0215] C-4: Flotation of the fourth type of ferroic quartzite iron ore

[0216] The fourth type of iron quartzite (41.9% Fe and 41.0% SiO2) containing small amounts of kaolinite and muscovite (each <2%) was ground to the particle size shown in Table C-4-1. The iron was mainly contained in the form of hematite.

[0217] Table C-4-1: Particle size distribution of ground ferroquartzite-type iron ore

[0218] Size range [μm] 400-213 212-151 150-107 106-90 89-64 63-38 <38 Weight fraction [%) 1.8 6.1 9.2 5.3 15.4 22 40.1

[0219] 500g of ground ore and 400mL of Ludwigshafen tap water were placed in a 1.2L clear plexiglass flotation cell of a Denver D12 flotation machine and stirred at 1200rpm. The slurry was adjusted for 5 minutes with the causticized starch solution prepared as described above (corresponding to 560g of starch per ton of solid ore). The pH was raised to 9.8 using a 10% by weight NaOH aqueous solution. Subsequently, a 1% by weight collector aqueous solution was added to the slurry and adjusted for 3 minutes. After adjustment, 250mL of Ludwigshafen tap water was added, and the slurry was aerated at 100L / h until the flotation was completed (3 minutes). The froth fraction was collected in a tray. The pH was monitored and maintained at 9.4-9.7 as needed by adding 10% by weight NaOH solution dropwise. The water level was kept approximately constant throughout the flotation time. Aeration was stopped after froth formation was complete. The remaining trough fraction (further described as concentrate) and froth fraction were dried in an oven at 70°C, weighed, homogenized, and their Fe and Si contents were determined using WDXRF in a lithium borate molten bead matrix. The Si content was recorded as SiO2. The results are listed in Table C-4-2.

[0220] Table C-4-2:

[0221]

[0222] footnote:

[0223] a) Comparison.

[0224] b) According to the present invention.

[0225] c) Fe recovery rate refers to the ratio of the total amount of Fe atoms in the cell fraction to the total amount of Fe atoms in the ore used as raw material.

[0226] d.1) Fe concentrate grade refers to the iron atom content in the tailings fraction. d.2) Fe concentrate grade refers to the iron atom content in the tailings fraction.

[0227] e) Si recovery rate refers to the ratio of the total number of Si atoms in the cell fraction to the total number of Si atoms in the ore used as raw material.

[0228] f) SiO2 concentrate grade refers to the SiO2 content in the trough fraction.

[0229] The results in Table C-4-2 show that Example C-1, using a single collector A-3, exhibits improved iron recovery compared to Example C-4-3, which uses a single collector A-5. Furthermore, the SiO2 content is lower. Both contribute to better separation efficiency. This is significant given the structural differences between A-3 and A-5, as described above for Example C.3. Additionally, A-6 is a powerful but silica-selective collector that produces high-grade iron concentrate, but with very high iron loss in the tailings.

Claims

1. A method for producing an iron-rich concentrate from an ore containing iron minerals and silicates by reverse flotation, the method comprising the following steps: (c) Adding the first amine (A) to an aqueous slurry of the prepared ore and optionally one or more flotation aids to obtain an aqueous mixture. Characterized by the fact that the first amine (A) is Compounds of Formula I, protonated compounds of Formula I, and salts of the first anion, or mixtures thereof: (I) Where R 1 and R 2 They are independently methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl, hexyl, heptyl, or 2-methylhexyl.

2. The method according to claim 1, wherein the method comprises the following steps: (a) Provide ore containing iron minerals and silicates, (b) Aqueous slurry is prepared from the provided ore by adding water and optionally one or more flotation aids. (c) Adding a first amine (A) to an aqueous slurry of the prepared ore and optionally one or more flotation aids to obtain an aqueous mixture, wherein the first amine (A) is a compound of formula I, a protonated compound of formula I, and a salt of a first anion, or a mixture thereof: (I) Where R 1 and R 2 Each of the following can be methyl, ethyl, propyl, 1-methylethyl, butyl, pentyl, hexyl, heptyl, or 2-methylhexyl; (d) Aerating the aqueous mixture in a flotation cell to produce silicate-rich foam, and removing the resulting foam from the flotation cell. (e) Obtaining a concentrate rich in iron minerals from the flotation cell.

3. The method according to claim 1 or 2, wherein a second amine (B) is further added in step (c), which is: Compounds of Formula II, protonated compounds of Formula II, salts of the second anion, or mixtures thereof: (II) Where R 3 For branched or linear C5-C 17 Alkyl, branched, or straight-chain C5-C 17 Alkenyl group.

4. The method according to claim 1 or 2, wherein R 1 and R 2 Each of them is independently methyl, ethyl, propyl, 1-methylethyl, butyl, or pentyl.

5. The method according to claim 3, wherein R 1 and R 2 Each of them is independently methyl, ethyl, propyl, 1-methylethyl, butyl, or pentyl.

6. The method according to claim 1 or 2, wherein R 1 and R 2 same.

7. The method of claim 3, wherein R 1 and R 2 same.

8. The method of claim 5, wherein R 1 and R 2 same.

9. The method of claim 3, wherein R 3 For branched or straight-chain C7-C 12 alkyl.

10. The method of claim 7, wherein R 3 For branched or straight-chain C7-C 12 alkyl.

11. The method according to claim 1 or 2, wherein R 1 and R 2 It is propyl.

12. The method of claim 9, wherein R 1 and R 2 It is propyl.

13. The method of claim 3, wherein R 3 It is 1-ethylpentyl.

14. The method of claim 12, wherein R 3 It is 1-ethylpentyl.

15. The method according to claim 3, wherein in step (c), the weight ratio of the first amine (A) to the second amine (B) is 0.1-10.

16. The method according to claim 14, wherein in step (c), the weight ratio of the first amine (A) to the second amine (B) is 0.1-10.

17. The method according to claim 15, wherein in step (c), the weight ratio of the first amine (A) to the second amine (B) is 0.2-1.

18. The method according to claim 1 or 2, wherein the first anion is C1-C. 18 Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, phosphate, nitrate, hydrofluorosilicate, fluorosilicate, or mixtures thereof.

19. The method according to claim 3, wherein the second anion is C1-C 18 Carboxylate, fluoride, chloride, bromide, iodide, sulfonate, hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, nitrate, hydrofluorosilicate, fluorosilicate, or mixtures thereof.

20. The method according to claim 1 or 2, wherein the first amine (A) is added in an amount of 10-500 g per ton of ore.

21. The method according to claim 3, wherein the sum of the weights of the first amine (A) and the second amine (B) added is 10-500 g per ton of ore.

22. The method according to claim 1 or 2, wherein the pH value in step (c) is 8-12.

23. The method of claim 3, wherein the pH value in step (c) is 8-12.

24. The method of claim 1 or 2, wherein the ore contains 20-55% by weight of iron, the weight percentage being based on the weight of the ore.

25. The method according to claim 1 or 2, wherein all iron minerals in the ore are non-sulfide iron minerals.

26. The method according to claim 1 or 2, wherein the iron mineral in the ore contains iron oxides.

27. The method of claim 26, wherein the iron mineral comprises hematite, magnetite, or goethite, or a mixture of two or three thereof.

28. The method of claim 2, wherein one or more flotation aids are added in step (b), and one of the flotation aids is an inhibitor, a foam modifier, a collector aid, or a filler oil.

29. The method of claim 28, wherein an inhibitor is added as a flotation aid, and the inhibitor is starch.

30. The use of a first amine (A) as a flotation collector for producing a concentrate rich in iron minerals from ores containing iron minerals and silicates by reverse flotation, characterized in that, The first amine (A) is a compound of formula I as defined in claim 1, a protonated compound of formula I, and a salt of the first anion or a mixture thereof.

31. The use according to claim 30, wherein the combination of the first amine (A) and the second amine (B) is used as a flotation collector for producing a concentrate rich in iron minerals from an ore containing iron minerals and silicates by reverse flotation, wherein the second amine (B) is a compound of formula II as defined in claim 3, a protonated salt of a compound of formula II, or a mixture thereof.

32. A non-binder composition for use as a flotation collector, comprising: The first amine (A) is a compound of formula I as defined in claim 1, a protonated compound of formula I, and a salt of the first anion, or a mixture thereof. The second amine (B) is a compound of formula II as defined in claim 3, a protonated compound of formula II, and a salt of the first anion, or a mixture thereof. The weight ratio of the first amine (A) to the second amine (B) is 0.2-1.

33. The composition according to claim 32, wherein the composition used as a flotation collector is a water-soluble composition.

34. The composition according to claim 32 or 33, wherein the sum of the weights of the first amine (A) and the second amine (B) is 50-100% by weight, said weight percentage being based on the total weight of the composition.

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