Efficient fluorite collecting agent and preparation method thereof

Abstract

The invention discloses a high-efficiency fluorite collecting agent and a preparation method thereof. The high-efficiency fluorite collecting agent comprises the following raw materials in parts by weight: 20-45 parts of oleic acid with different iodine values, 5-10 parts of an amidate surfactant, 3-5 parts of inorganic alkali or organic alkali and 10-25 parts of a low-carbon-chain alcohol compound. The amidate surfactant is a nonionic surfactant, the structural general formula of the amidate surfactant is R1-C (O) NH (CH2) nCH2-R2, in the formula, R1 is a hydrocarbon chain containing 12-18 carbon atoms, n is equal to 5-6, and in the formula, R2 is a functional group with a hydrogen bond effect. According to the fluorite collecting agent, the efficient recovery rate of fluorite is guaranteed, meanwhile, the grade of fluorite concentrate is improved to a certain degree, the using amount of the collecting agent is reduced, and the problem that the fatty acid fluorite collecting agent is poor in fluorite concentration efficiency is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral flotation collection, and in particular relates to a high-efficiency fluorite collector and a preparation method thereof. Background Art

[0002] Fluorite (CaF2) is an important non-renewable mineral. It is mainly used to make hydrofluoric acid, glass, cement, filler, and as a flux regulator in steelmaking. In recent years, it has been considered an important strategic mineral. In natural deposits, fluorite is mainly associated with other calcium-containing minerals, such as calcite and leucite. With the continuous reduction of high-quality fluorite resources, low-grade fluorite resources containing complex gangue minerals have also been developed and utilized, which has posed new challenges to fluorite beneficiation. In addition, production practice shows that when the ratio of fluorite content to calcite content in the original ore is less than 5, the difficulty of separating fluorite from calcite is greatly increased, and it is difficult to obtain high-quality fluorite concentrate products (CaF2>90%, CaCO3<1%). Therefore, it is particularly important to develop efficient and environmentally friendly fluorite flotation reagents.

[0003] So far, flotation using fatty acid collectors has been considered one of the most commonly used technologies for separating fluorite from gangue minerals. However, it should be noted that flotation separation of fluorite from calcium-containing minerals is a very challenging task. The difficulty lies in the fact that their surface reactivity is similar to the binding mode of traditional fatty acid collectors, and the solubility and dispersibility of fluorite collectors mainly based on fatty acids are poor, which will lead to a decrease in fluorite recovery rate, an increase in collector dosage, a reduction in atom economy, and a loss of corporate benefits.

[0004] In the prior art, in order to solve the problem that oleic acid collectors have poor collection capacity and many times of selection, for example, Chinese patent document CN114054213B discloses a fluorite collector and a preparation method thereof. Although the disclosed fluorite collector and its preparation method can improve the recovery rate of fluorite to a certain extent, the preparation process of the fluorite collector involves complex chemical reactions, which are dangerous and polluting. Therefore, the method has certain limitations. Chinese patent document CN107138288B discloses a low-temperature fluorite collector, specifically disclosing a fluorite collector prepared by mixing the product of complete saponification of oleic acid and sodium carbonate with an alkylamide and a foaming agent. The solubility and dispersibility of the fluorite collector are relatively good, but the foam is too abundant and relatively stable during the flotation process, and it is not easy to defoam, so the recovery rate will also decrease.

[0005] In summary, it is necessary to develop an efficient fluorite collector that has strong collection ability and selectivity under the condition of few selection times, can ensure a high fluorite recovery rate, has low raw material cost, and can produce foam of suitable size and stability during use, so as to solve the above problems. Summary of the invention

[0006] In order to overcome the problems in the prior art, the present invention provides a high-efficiency fluorite collector and a preparation method thereof, which can significantly reduce the number of selection times, ensure the high efficiency recovery rate of fluorite, while also improving the grade of fluorite concentrate to a certain extent, reducing the amount of collector used, and solving the problem of poor fluorite selection efficiency of fatty acid fluorite collectors.

[0007] In order to solve the above technical problems, the technical solution proposed by the present invention is: The present invention provides a high-efficiency fluorite collector, comprising the following raw materials in parts by weight: 20-45 parts of oleic acid with different iodine values, 5-10 parts of amidated surfactant, 3-5 parts of inorganic base or organic base, 10-25 parts of low-carbon chain alcohol compound; the amidated surfactant is a non-ionic surfactant, and the structural formula of the amidated surfactant is R1-C(O)NH(CH2) n R2, wherein R1 is a hydrocarbon chain containing 12-18 carbon atoms, n=6-7, and R2 is a functional group having hydrophilic properties.

[0008] The amidate surfactant in the present invention is a nonionic surfactant, which is relatively stable in acid or alkali solution, can promote the dispersibility and foaming ability of oleic acid after alkalization, and has good emulsification, dispersion, foaming and non-fluorite impurity inhibition capabilities. The chemical formula of the amidate surfactant has both an amide bond in the structure and a hydrophilic group at the tail. After being similarly soluble with oleic acid, it will not form a phase separation in water. At the same time, the low-carbon chain alcohol compound itself carries a single or multiple hydroxyl groups, has a strong polarity, and can well mix oleic acid alkalization, amidate, and water. At the same time, its defoaming ability is strong, and during the flotation process, the foam will not be difficult to eliminate and cause overflow from the flotation tank. At the same time, oleic acid with different iodine values ​​is used to improve the recovery rate and grade of fluorite, and alkali solution and oleic acid are used for acid-base neutralization.

[0009] As an optional embodiment, in the collector provided by the present invention, the R2 is selected from one of -H, -OH, and -COOH.

[0010] As an optional embodiment, in the collector provided by the present invention, R2 in the amidate surfactant is selected from -COOH.

[0011] In the present invention, under the condition of equally inhibiting gangue minerals, the addition of -COOH further increases the ability to capture fluorite.

[0012] As an optional embodiment, in the collector provided by the present invention, the amidate surfactant is composed of R1-COOCH3 and H2N(CH2)n R2 is formed by heating reaction under alkaline conditions in the presence of a catalyst.

[0013] The general synthetic formula is: .

[0014] As an optional embodiment, in the collector provided by the present invention, the R1-COOCH3 and H2N(CH2) n The molar ratio of R2 is 0.5-1.5.

[0015] As an optional embodiment, in the collector provided by the present invention, the catalyst is potassium hydroxide, and the amount of potassium hydroxide used is 0.5-5% of the total weight of the reactants.

[0016] As an optional embodiment, in the collector provided by the present invention, the low-carbon chain alcohol compound is selected from one or more of methanol, ethanol, ethylene glycol, diethylene glycol, isopropanol or glycerol.

[0017] As an optional embodiment, in the collector provided by the present invention, the inorganic base or organic base is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, diethylamine or triethylamine.

[0018] As an optional embodiment, in the collector provided by the present invention, the oleic acids with different iodine values ​​include at least one oleic acid with a high iodine value and at least one oleic acid with a low iodine value, and the iodine value of the high iodine value oleic acid ranges from 120 to 140; the iodine value of the low iodine value oleic acid ranges from 90 to 105.

[0019] As an optional embodiment, in the collector provided by the present invention, The structural formula of the oleic acid is shown below: .

[0020] Based on the same technical concept, the present invention also provides a method for preparing the above-mentioned high-efficiency fluorite collector, comprising the following steps: S1. Add alkali solution to oleic acid with different iodine values ​​to prepare a mixed solution with a mass concentration of 60%-80%.

[0021] S2. Add an amidate surfactant and a low-chain alcohol compound to the solution of step S1 in sequence to obtain a mixture.

[0022] S3, shearing and stirring the mixture obtained in step S2 for 20-30 minutes to mix evenly to obtain a high-efficiency fluorite collector.

[0023] As an optional embodiment, in the preparation method provided by the present invention, in step S1, oleic acid with different iodine values ​​is dissolved in alkali solution at 70-85° C. to prepare an oleic acid alkaline solution.

[0024] As an optional embodiment, in the preparation method provided by the present invention, in step S1, oleic acid with different iodine values ​​is dissolved in alkali solution at 85° C. to prepare an oleic acid alkaline solution with a mass concentration of 60%.

[0025] As an optional embodiment, in the preparation method provided by the present invention, in step S2, low-chain alcohol compounds and amide surfactants are added to the oleic acid alkaline solution in multiple times to ensure that the amide compounds will not undergo large-scale decomposition in the high-temperature alkaline solution.

[0026] The working principle of each raw material in the present invention is as follows: Oleic acid has a collecting effect on fluorite. Oleic acid has a long straight chain structure. From the hydrophile-lipophile balance theory, its carboxyl group is a hydrophilic group, and its α-position rear end is a fully hydrocarbon structure. Therefore, the hydrocarbon chain of oleic acid is more hydrophobic, making it easier to collect fluorite. At the same time, after oleic acid is saponified, its dispersibility is stronger.

[0027] The amidated surfactants are stable in nature, resistant to acid and alkali at room temperature, can promote the dispersibility and foaming ability of oleic acid after alkalization, and have the effect of inhibiting non-fluorite minerals, further improving the selectivity and collection effect of oleic acid. Compared with the commonly used oleic acid amide (R-CONH2 disclosed in the prior art CN11369021A), the amidated surfactant chemical formula in the present invention has both an amide bond in the structure and a hydrophilic group at the tail. After being similarly soluble in oleic acid, it will not form a phase separation in water.

[0028] Compared with the prior art, the present invention has the following beneficial effects: (1) The collector of the present invention uses an amide surfactant, the chemical structure of which contains both an amide bond and a group having a hydrophilic effect such as -H, -OH, or -COOH connected to the tail. After being similarly soluble in oleic acid, it will not form a phase separation in water.

[0029] (2) The collector of the present invention is prepared by compounding oleic acid, inorganic or organic base, amide surfactant and low-carbon alcohol. Except for the amide surfactant, the other raw materials are common chemical products on the market. The raw materials are easy to obtain, low in cost, environmentally friendly, and easily degradable, and have great market promotion value.

[0030] (3) Compared with general fatty acid collectors, the collector provided by the present invention has greatly improved collection performance, can significantly reduce the number of concentration times, greatly improve the recovery rate of fluorite ore, reduce the amount of collector used, and ensure the quality of the concentrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 The present invention is a flow chart of applying the high-efficiency fluorite collector to the flotation of fluorite ore. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0034] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0035] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0036] Example 1 The high-efficiency fluorite collector of this embodiment has the following weight proportions of the raw materials: 20 parts of oleic acid with an iodine value of 120, 20 parts of oleic acid with an iodine value of 90, 10 parts of an amide compound surfactant (R1 is a hydrocarbon chain with 15 carbon atoms, R2 is H, and n=6), 5 parts of an inorganic base, sodium hydroxide, and 10 parts of isopropanol.

[0037] The preparation method of high-efficiency fluorite collector is as follows: (1) Add liquid alkali to oleic acid to prepare a mixed solution with a mass concentration of 70%.

[0038] (2) The synthetic chemical formula of amide compound surfactant is as follows: where CH3(CH2) 14 The molar ratio of COOCH3 and H2N(CH2)5CH3 is 1:2, and the amount of potassium hydroxide added is 1% of the total weight of the reactants.

[0039] .

[0040] (3) Adding an amide compound surfactant and isopropanol to the oleic acid alkaline solution of step (1) in sequence to obtain a mixture.

[0041] (4) The mixture obtained in step (3) is sheared and stirred for 20-30 minutes to mix evenly to obtain a high-efficiency fluorite collector.

[0042] The use effects of the high-efficiency fluorite collector in this embodiment are compared with those of the prior art fluorite collector.

[0043] The high-efficiency fluorite collector prepared in this embodiment and the prior art fluorite collector were respectively applied to the flotation of fluorite raw ore CaF2 with a feed sample content of 13.18%, see Figure 1 The flotation process shown is as follows: the adjusting agent is sodium carbonate, the depressant is water glass, and the comparison results of the use effects are shown in Table 1.

[0044] Table 1: Flotation results

[0045] From the comparison results, it can be seen that in room temperature slurry, under the condition of the same collector dosage, the fluorite concentrate obtained by using the collector of Example 1 is about 21% higher than that of the traditional sodium oleate, and the grade of the fluorite concentrate is still maintained above 90%. Using a single high iodine value and low iodine value oleic acid composite mixture can improve the collection capacity to a certain extent, but the sorting is poor and the overall effect is not significant.

[0046] Example 2 The high-efficiency fluorite collector of this embodiment has the following weight proportions of the raw materials: 10 parts of oleic acid with an iodine value of 140, 10 parts of oleic acid with an iodine value of 90, 10 parts of an amidate surfactant (R1 is a hydrocarbon chain with 17 carbon atoms, R2 is -OH, n=5), 5 parts of an organic base diethylamine, and 10 parts of diethylene glycol.

[0047] Preparation of fluorite low temperature collector in this embodiment: (1) Add liquid alkali to oleic acid to prepare a mixed solution with a mass concentration of 70%.

[0048] (2) The synthetic chemical formula of amide compound surfactant is as follows, where CH3(CH2) 16 The molar ratio of COOCH3 and H2N(CH2)5OH is 1:1, and the amount of potassium hydroxide added is 1.5% of the total weight of the reactants.

[0049] .

[0050] (3) Adding an amide compound surfactant and isopropanol to the oleic acid alkaline solution of step (1) in sequence to obtain a mixture.

[0051] (4) The mixture obtained in step (3) is sheared and stirred for 20-30 minutes to mix evenly to obtain a high-efficiency fluorite collector.

[0052] The use effects of the high-efficiency fluorite collector in this embodiment are compared with those of the prior art fluorite collector.

[0053] The high-efficiency fluorite collector prepared in this embodiment and the prior art fluorite collector were respectively applied to the flotation of fluorite raw ore CaF2 with a feed sample content of 13.18%, see Figure 1 The flotation process shown is as follows: the adjusting agent is sodium carbonate, the depressant is water glass, and the comparison results of the use effects are shown in Table 2.

[0054] Table 2: Flotation results

[0055] From the comparison results, it can be seen that in room temperature slurry, under the condition of the same collector dosage, the fluorite concentrate obtained by using the collector of Example 2 is about 7.5% higher than that of the traditional sodium oleate, and the grade of the fluorite concentrate is still maintained at more than 90%. In the comparative experiment, a single equivalent amount of amidate surfactant was used as a collector, and it was found that its collection ability was poor, and it needed to be combined with oleic acid and other additives to produce a positive synergistic effect, so as to improve the fluorite recovery rate while ensuring the fluorite grade.

[0056] Example 3 The high-efficiency fluorite collector of this embodiment has the following weight proportions of the raw materials: 20 parts of oleic acid with iodine value = 140, 10 parts of oleic acid with iodine value = 100, 10 parts of amide surfactant (R1 is a hydrocarbon chain with 13 carbon atoms, R2 is -COOH, n=5), 5 parts of inorganic base potassium hydroxide, and 5 parts of methanol.

[0057] Preparation of fluorite low temperature collector in this embodiment: (1) Add liquid alkali to oleic acid to prepare a mixed solution with a mass concentration of 70%.

[0058] (2) The synthetic chemical formula of amide compound surfactant is as follows, where CH3(CH2) 12 The molar ratio of COOCH3 and H2N(CH2)5COOH is 1:1.5, and the amount of potassium hydroxide added is 5% of the total weight of the reactants.

[0059] .

[0060] (3) Adding an amide compound surfactant and isopropanol to the oleic acid alkaline solution of step (1) in sequence to obtain a mixture.

[0061] (4) The mixture obtained in step (3) is sheared and stirred for 20-30 minutes to mix evenly to obtain a high-efficiency fluorite collector.

[0062] The use effects of the high-efficiency fluorite collector in this embodiment are compared with those of the prior art fluorite collector.

[0063] The high-efficiency fluorite collector prepared in this embodiment and the prior art fluorite collector were respectively applied to the flotation of fluorite raw ore CaF2 with a feed sample content of 13.18%, see Figure 1 The flotation process shown is as follows: the adjusting agent is sodium carbonate, the depressant is water glass, and the comparison results of the use effects are shown in Table 3.

[0064] Table 3: Flotation results

[0065] From the comparison results, it can be seen that in room temperature slurry, under the condition of the same collector dosage, after adding an appropriate amount of lower alcohol to the collector in Example 3, although the concentrate recovery rate will decrease slightly, the concentrate grade will increase significantly. The reason is that in the comparative test without adding lower alcohol, the amount of foam in the flotation process is large and difficult to eliminate, non-fluorite mineral impurities are easily floated, and the sorting efficiency is reduced.

[0066] Comparative Example 1 The weight proportion of each raw material is: 10 parts of oleic acid with iodine value = 140, 10 parts of oleic acid with iodine value = 90, 10 parts of oleic acid amide, 5 parts of organic base diethylamine, 10 parts of diethylene glycol, and the ordinary fluorite collector is synthesized. The preparation method is the same as that of Example 2.

[0067] The collector in comparative example 1 and the high-efficiency fluorite collector in example 2 were respectively applied to the flotation of fluorite raw ore CaF2 with a sample concentration of 13.18%, see Figure 1 The flotation process shown is as follows: the adjusting agent is sodium carbonate, the depressant is water glass, and the comparison results of the use effects are shown in Table 4.

[0068] Table 4: Flotation results

[0069] From the comparison results, it can be seen that in room temperature slurry, when the amount of collector is the same, after oleic acid amide is used in the collector of Comparative Example 1, the concentrate recovery rate decreases and the concentrate grade also decreases. The reason is that the oleic acid amide in Comparative Example 1 has no hydrophilic group -OH at the tail, and after mixing with oleic acid, the compatibility is poor and the sorting efficiency decreases.

[0070] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A high-efficiency fluorite collector, characterized in that: The following materials are included in parts by weight: 20-45 parts of oleic acid with different iodine values, 5-10 parts of amidated surfactant, 3-5 parts of inorganic base or organic base, 10-25 parts of low-carbon chain alcohol compound; the amidated surfactant is a non-ionic surfactant, and the structural formula of the amidated surfactant is R1-C(O)NH(CH2) n R2, wherein R1 is a hydrocarbon chain containing 12-18 carbon atoms, n=6-7, and R2 is a functional group having hydrophilic properties.

2. The high-efficiency fluorite collector according to claim 1, characterized in that: The R2 is selected from one of -H, -OH, and -COOH.

3. The high-efficiency fluorite collector according to claim 1, characterized in that: The R2 is selected from -COOH.

4. The high-efficiency fluorite collector according to claim 1, characterized in that: The amidate surfactant is composed of R1-COOCH3 and H2N(CH2) n R2 is formed by heating reaction under alkaline conditions in the presence of a catalyst.

5. The high-efficiency fluorite collector according to claim 4, characterized in that: The R1-COOCH3 and H2N(CH2) n The molar ratio of R2 is 0.5-1.

5.

6. The high-efficiency fluorite collector according to claim 4, characterized in that: The catalyst is potassium hydroxide, and the amount of potassium hydroxide used is 0.5-5% of the total weight of the reactants.

7. The high-efficiency fluorite collector according to claim 1, characterized in that: The low-carbon chain alcohol compound is selected from one or more of methanol, ethanol, ethylene glycol, diethylene glycol, isopropanol or glycerol; the inorganic base or organic base is one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, diethylamine or triethylamine.

8. A method for preparing a high-efficiency fluorite collector as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Add alkali solution to oleic acid with different iodine values ​​to prepare a mixed solution with a mass concentration of 60%-80%; S2, adding an amidate surfactant and a low-carbon chain alcohol compound to the solution of step S1 in sequence to obtain a mixture; S3, shearing and stirring the mixture obtained in step S2 for 20-30 minutes to mix evenly to obtain a high-efficiency fluorite collector.

9. The method for preparing a high-efficiency fluorite collector according to claim 8, characterized in that: In step S1, oleic acid with different iodine values ​​is dissolved in alkali solution at 70-85° C. to prepare an oleic acid alkaline solution.

10. The method for preparing a high-efficiency fluorite collector according to claim 8, characterized in that: In step S2, low-carbon chain alcohol compounds and amide surfactants are added to the oleic acid alkaline solution in multiple times to ensure that the amide compounds will not be decomposed in large quantities in the high-temperature alkaline solution.

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