Amidated carboxylic acid compound, collecting agent for spodumene flotation and preparation method and application of amidated carboxylic acid compound and collecting agent for spodumene flotation

Abstract

The invention belongs to the technical field of mineral separation, and discloses an amidated carboxylic acid compound, a collecting agent for spodumene flotation, a preparation method of the amidated carboxylic acid compound and application of the amidated carboxylic acid compound in spodumene flotation. The amidated carboxylic acid compound is obtained through the reaction of amino acid, acyl chloride and sodium hydroxide, is resistant to acid and alkali in the normal temperature state, is not prone to decomposition and can improve the selectivity of the collecting agent. The collecting agent comprises 30-45 parts of amidated carboxylic acid compounds, 5-15 parts of oleic acid, 3-10 parts of inorganic base and 10-25 parts of alcohol compounds. The spodumene flotation collecting agent has good dispersity, foaming capacity and capacity of inhibiting gangue, feldspar and quartz minerals, has a good collecting effect on spodumene at the room temperature, remarkably improves ore selectivity, guarantees the concentrate grade of spodumene, meanwhile improves the recovery rate and has a good application effect in spodumene flotation.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal beneficiation, and in particular relates to an amidated carboxylic acid compound, an amidated organic carboxylic acid collector for spodumene flotation, a preparation method and applications thereof. Background Art

[0002] Lithium, an energy metal often referred to as "white oil," is widely used in new energy sectors such as aerospace, lithium batteries, and nuclear energy. Spodumene (LiAl[Si2O6]) is one of the most important sources of lithium minerals. Spodumene contains approximately 8% lithium oxide, making it the most abundant lithium-bearing mineral. Many lithium companies use spodumene as their primary source and convert it into lithium. Due to the similar physical and chemical properties of lithium minerals, separation from similar gangue minerals (such as quartz, feldspar, and mica) is often challenging.

[0003] Flotation is currently the most widely used mineral processing method. In the field of spodumene flotation research, the high-alkali, non-desliming method has been widely promoted, greatly simplifying the flotation process. However, the choice of flotation reagent is the most important factor in the high-alkali, non-desliming process. The development of spodumene mineral processing has been severely limited by the lack of high selectivity and capture capacity of traditional collectors used in spodumene flotation. Therefore, the search for new flotation collectors is necessary. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings and defects mentioned in the above background technology and provide an amidated carboxylic acid compound that can be used for spodumene flotation, a preparation method and its composite application, so as to solve the problems in the prior art that spodumene flotation collectors are difficult to achieve good flotation indicators during the flotation process, the dissolution and dispersion effects of low-temperature collectors are poor, and the concentrate grade is low.

[0005] In the field of spodumene flotation, carboxylic acid collectors with amide structures not only extend their carbon chains and enhance capture performance, but also possess significant selectivity, significantly improving the grade of concentrates from spodumene flotation. Therefore, combining carboxylic acid and amide groups within a single molecular structure enables efficient and selective flotation of spodumene. Currently, there are no reports of compounds containing carboxylic acid and amide groups being used for spodumene flotation.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is: In a first aspect, the present invention provides an amidated carboxylic acid compound having the structural formula: .

[0007] Preferably, the amidated carboxylic acid compound is obtained by reacting an amino acid, an acyl chloride and sodium hydroxide, and is an anion collector.

[0008] In a second aspect, the present invention provides a method for preparing an amidated carboxylic acid compound, comprising the following steps: adding water to an amino acid and stirring, then dropwise adding acyl chloride, sodium hydroxide and water, and reacting to obtain the amidated carboxylic acid compound.

[0009] The general synthetic formula of amidated carboxylic acid compounds is: .

[0010] In the above preparation method, preferably, the amino acid is at least one of glycine, threonine, lysine, and leucine; and the acyl chloride is at least one of lauroyl chloride, myristoyl chloride, palmitoyl chloride, and oleoyl chloride. Water is used as the reaction solvent and does not participate in the reaction.

[0011] Preferably, the molar ratio of the amino acid, acyl chloride, and sodium hydroxide is 0.1-0.12:0.1-0.15:0.22-0.3, the total amount of water added is 12-15 times the mass of the amino acid, the temperature for dropwise addition of acyl chloride, sodium hydroxide, and water is 0-5°C, and the dropwise addition time is controlled at 30-45 minutes; the reaction temperature is 20-30°C, and the reaction time is 3-5 hours.

[0012] In a third aspect, the present invention provides a collector for spodumene flotation, wherein the raw materials thereof include, by weight, 30-45 parts of the amidated carboxylic acid compound, 5-15 parts of oleic acid, 3-10 parts of an inorganic base, and 10-25 parts of an alcohol compound.

[0013] Preferably, the inorganic base is sodium hydroxide or potassium hydroxide.

[0014] Preferably, the alcohol compound is at least one of methanol, ethanol, ethylene glycol, diethylene glycol, isopropanol and glycerol.

[0015] Preferably, the iodine value of the oleic acid is in the range of 90-140.

[0016] In a fourth aspect, the present invention provides a method for preparing the collector, comprising the following steps: (1) Adding an inorganic alkali aqueous solution to oleic acid to prepare an oleic acid alkaline solution; (2) adding an amidated carboxylic acid compound and an alcohol compound to the alkaline oleic acid solution obtained in step (1) in sequence to obtain a mixture; (3) The mixture obtained in step (2) is sheared and stirred to mix uniformly to obtain the collector for spodumene flotation.

[0017] In the above preparation method, preferably, in step (1), oleic acid is dissolved in an inorganic liquid alkali at 70-85° C. to prepare an oleic acid alkaline solution with a mass concentration of 60%-80%.

[0018] Preferably, in step (1), oleic acid is dissolved in an inorganic alkaline aqueous solution at 70-85° C. to prepare an oleic acid alkaline solution with a mass concentration of 60%.

[0019] Preferably, in step (2), the time interval between sequentially adding the amidated carboxylic acid compound and the alcohol compound to the oleic acid alkaline solution is 4-6 minutes to ensure that the amide compound does not undergo a large amount of decomposition in the high-temperature alkaline solution; in step (3), the shear stirring time is 20-30 minutes.

[0020] In a fifth aspect, the present invention provides an application of the collector in spodumene flotation.

[0021] The collector of the present invention has a good collecting effect on spodumene at room temperature, ensuring a high recovery rate of spodumene while also improving the grade of spodumene concentrate to a certain extent and reducing the amount of collector used. The main principles of the present invention are: 1) The amidated carboxylic acid compounds of the present invention are acid and alkali resistant and not easily decomposed at room temperature. Compared with conventional oleic acid collectors, they have stronger collecting ability. In addition, their amide bonds have the effect of inhibiting gangue and feldspar minerals, further improving the selectivity of the collector.

[0022] 2) Oleic acid has a certain collecting effect on spodumene. Oleic acid has a long straight chain structure. According to the hydrophilic-lipophilic 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 highly hydrophobic, making it easier to collect spodumene. At the same time, after saponification, oleic acid has stronger dispersibility and can be similarly soluble in the main component, amidated carboxylic acid, thereby enhancing the collection performance.

[0023] 3) The main advantage of selecting low-carbon chain alcohol compounds in the present invention is that they have single or multiple hydroxyl groups and are highly polar, which can effectively dissolve oleic acid alkalization products, amidation products, and water. At the same time, they have strong defoaming ability. During the flotation process, the foam will not be difficult to eliminate and will not overflow the flotation tank.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. The amidated carboxylic acid compounds of the present invention are acid and alkali resistant at room temperature and are not easily decomposed. Compared with conventional oleic acid collectors, they have stronger collecting ability. In addition, their amide bonds have the effect of inhibiting gangue and feldspar minerals, further improving the selectivity of the collector. The reaction raw materials of the amidated carboxylic acid are readily available, the reaction conditions are relatively mild, and the preparation process is simple.

[0025] 2. The collector provided by the present invention has good dispersibility, foaming ability and the ability to inhibit gangue, feldspar and quartz minerals. It has a good collection effect on spodumene at room temperature, significantly improves the ore selectivity, ensures the concentrate grade of spodumene, and improves the recovery rate.

[0026] 3. The preparation method of the present invention is simple to operate, and the amide compounds will not undergo a large amount of decomposition in a high-temperature alkaline solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0028] Figure 1 is the H NMR spectrum of the amidated carboxylic acid compound in Example 1 of the present invention ( 1 H NMR).

[0029] Figure 2 is the carbon NMR spectrum of the amidated carboxylic acid compound in Example 1 of the present invention ( 13 C NMR).

[0030] Figure 3 This is the FT-IR spectrum of the amidated carboxylic acid compound in Example 1 of the present invention.

[0031] Figure 4 This is a flow chart of applying the collector in Example 2 of the present invention to the flotation of spodumene ore. DETAILED DESCRIPTION

[0032] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical 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.

[0034] 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.

[0035] Example 1 An amidated carboxylic acid compound, the synthetic chemical formula of which is: ; The preparation method of the amidated carboxylic acid compound is as follows: (1) In a three-necked flask, add 0.1 mol of glycine and 50 g of water and stir thoroughly; (2) Add 0.1 mol of oleyl chloride, 0.22 mol of sodium hydroxide and 25 g of water dropwise at 5°C and stir thoroughly for 30 minutes; (3) The reaction was continued at 30°C for 3 h to obtain the target product, an amidated carboxylic acid compound.

[0036] After adding dilute hydrochloric acid to acidify to pH=2, its nuclear magnetic resonance spectrum ( Figure 1-Figure 2 ) and infrared analysis ( Figure 3 )as follows: Figure 1-Figure 2 visible, 1 H NMR (500 MHz, Chloroform-d) δ 6.50 (s, 1H), 5.34 (qd,J = 10.6, 5.7 Hz, 3H), 4.04 (d, J = 5.1 Hz, 2H), 2.26 (t, J = 7.7 Hz, 1H), 2.01 (dq, J = 19.3, 7.0 Hz, 3H), 1.61 (q, J = 7.3 Hz, 2H), 1.38-1.17 (m,22H), 0.87 (t, J = 6.3 Hz, 3H). 13 C NMR (126 MHz, CDCl3) δ 174.92, 172.73,130.27, 130.05, 129.73, 127.93, 41.57, 36.28, 31.95, 31.56, 29.76, 29.57,29.37, 29.28, 29.23, 29.18, 27.24, 25.63, 22.72, 14.15.

[0037] Depend on Figure 3 Visible, IR (KBr), ν (cm -1 ): 3311(OH), 2922 (CH), 2850 (CH), 1699(C=O), 1645 (C=O), 1546 (NH).

[0038] The carbonyl and amino groups are respectively detected in the NMR carbon spectrum 13The appearance of special peaks at C NMR (126 MHz, CDCl3) δ 174.92, 172.73 and hydrogen spectrum δ 6.50 (s, 1H), as well as the appearance of two characteristic carbonyl peaks around 1699 and 1650 in the infrared spectrum, indicate that the amidated carboxylic acid has been successfully synthesized with the general structural formula R1-C(O)NHCH2-COONa, where R1 is a hydrocarbon chain alkane containing 17 carbon atoms.

[0039] Example 2 A collector for spodumene flotation, comprising the following raw materials in the following weight proportions: 5 parts of oleic acid having an iodine value of 140, 30 parts of the amidated carboxylic acid compound of Example 1 (with a general structural formula of R1-C(O)NHCH2-COONa, where R1 is a hydrocarbon chain alkane containing 17 carbon atoms), 3 parts of potassium hydroxide, and 10 parts of isopropyl alcohol. The present embodiment is used for the preparation method of the collector of spodumene flotation: (1) Dissolve oleic acid in a 50% potassium hydroxide aqueous solution at 70°C to prepare a 70% oleic acid alkaline solution (the alkali reacts with oleic acid to form oleate); (2) adding the amidated carboxylic acid compound of Example 1 and isopropanol to the oleic acid alkaline solution of step (1) in sequence at intervals of 5 minutes to obtain a mixture; (3) The mixture obtained in step (2) is sheared and stirred for 20-30 minutes to mix uniformly to obtain a collector for spodumene flotation. The collector prepared in this embodiment, the prior art collector, and the collector without adding organic solvent were respectively applied to the flotation of spodumene ore Li2O with a feed sample content of 0.43%. Figure 4 The flotation process shown is as follows: the adjusting agent is sodium carbonate 1600g / t, sodium hydroxide 800g / t, and the activating agent is calcium chloride 80g / t. The comparison results of the use effects are shown in Table 1. Table 1: Flotation results

[0040] Comparative results show that, in room-temperature slurry, when the collector dosage of this embodiment is lower than that of conventional sodium oleate, the spodumene concentrate recovery rate achieved using this embodiment's collector is approximately 5% higher than that of conventional sodium oleate, and the spodumene concentrate grade is increased by approximately 1.8%. When the collector dosage of this embodiment is the same as that of a collector without an organic solvent, the addition of an appropriate amount of lower alcohol (isopropyl alcohol) to this embodiment's collector significantly increases the concentrate grade. This is because, in the comparative test without the addition of lower alcohol, the flotation process produces a large amount of foam that is difficult to dissipate, making non-spodumene mineral impurities easily floated and reducing separation efficiency.

[0041] Example 3 A collector for spodumene flotation, comprising the following raw materials in the following weight proportions: 5 parts of oleic acid having an iodine value of 100, 40 parts of the amidated carboxylic acid compound of Example 1 (with the general structural formula R1-C(O)NHCH2-COONa, where R1 is a hydrocarbon chain olefin containing 17 carbon atoms), 5 parts of sodium hydroxide, and 10 parts of diethylene glycol. The present embodiment is used for the preparation method of the collector of spodumene flotation: (1) Dissolve oleic acid in a sodium hydroxide aqueous solution to prepare a mixed solution with a mass concentration of 70%; (2) adding the amidated carboxylic acid compound of this example and diethylene glycol to the oleic acid alkaline solution of step (1) in sequence at intervals of 5 minutes to obtain a mixture; (3) The mixture obtained in step (2) is sheared and stirred for 20-30 minutes to mix uniformly to obtain a collector for spodumene flotation. The collector prepared in this example and the collector of the prior art were respectively applied to the flotation of spodumene ore with a Li2O content of 0.43% in the sample. Figure 4 The flotation process shown is as follows: the adjusting agent is sodium carbonate 1600g / t, sodium hydroxide 800g / t, and the activating agent is calcium chloride 80g / t. The comparison results of the use effects are shown in Table 2.

[0042] Table 2: Flotation results

[0043] As can be seen from the comparative results, in room temperature slurry, when the collector dosage is the same, the spodumene concentrate recovery rate obtained by using the collector of this embodiment is about 15% higher than that of traditional sodium oleate, and the spodumene concentrate grade is maintained at above 5%. In the comparative experiment, a single equivalent amount of amidated carboxylic acid compound was used as a collector, and it was found that its collection ability was poor. It was necessary to combine it with oleic acid and other additives to produce a positive synergistic effect, thereby improving the spodumene recovery rate while ensuring the spodumene grade.

[0044] Comparative Example 1 Compared with Example 3, the only difference is that collector a ( ) was used as a collector, with an increased dosage of Collector a, in the primary roughing of spodumene ore containing 0.43% LiO in the feed sample: Collector a at 1000 g / t. All other operations and parameters were the same as in Example 1. The test results are shown in Table 1. As shown in Table 1, when Comparative Collector a was used as the collector, the LiO grade in the lithium concentrate was only 4.36%, and the recovery rate was only 52.93%. These results demonstrate that Comparative Collector a is significantly less effective than the collector used in the present invention in flotation of lower-grade spodumene ore.

[0045] Table 1: Effects of Collector a in Comparative Example 1 and Collector in Example 3 on Spodumene Flotation

[0046] Comparative Example 2 Compared to Example 3, the only difference is that collector b (with the general formula R1-CONHCH2CH2OHCOONa, where R1 is a hydrocarbon chain olefin containing 17 carbon atoms) is used as the collector, and the dosage of collector b is increased. For example, in the primary roughing of spodumene ore with a Li2O content of 0.43% in the feed sample, 800 g / t of collector b was used. All other operations and parameters were the same as in Example 1. The test results are shown in Table 2. As shown in Table 2, when collector b was used as the collector, the Li2O grade in the lithium concentrate was only 4.32%, and the recovery rate was only 65.09%. These results demonstrate that collector b is significantly less effective than the collector used in the present invention in flotation of lower-grade spodumene ore.

[0047] Table 2: Effects of Collector b of Comparative Example 2 and Collector b of Example 3 on Spodumene Flotation

Claims

1. An amidated carboxylic acid compound, characterized in that: Its structural formula is: 。 2. A method for preparing an amidated carboxylic acid compound according to claim 1, characterized in that: The method comprises the following steps: adding water to an amino acid and stirring, then dropwise adding acyl chloride, sodium hydroxide and water, and reacting to obtain the amidated carboxylic acid compound.

3. The method for preparing the amidated carboxylic acid compound according to claim 2, wherein: The amino acid is at least one of glycine, threonine, lysine and leucine; and the acyl chloride is at least one of lauroyl chloride, myristoyl chloride, palmitoyl chloride and oleoyl chloride.

4. The method for preparing the amidated carboxylic acid compound according to claim 3, wherein: The molar ratio of the amino acid, acyl chloride, and sodium hydroxide is 0.1-0.12:0.1-0.15:0.22-0.3, the total amount of water added is 12-15 times the mass of the amino acid, the temperature for dropwise addition of acyl chloride, sodium hydroxide, and water is 0-5°C, and the dropwise addition time is controlled at 30-45 minutes; the reaction temperature is 20-30°C, and the reaction time is 3-5 hours.

5. A collector for spodumene flotation, characterized in that: The raw materials include, by weight, 30-45 parts of the amidated carboxylic acid compound according to claim 1 or the amidated carboxylic acid compound obtained by the preparation method according to any one of claims 2-4, 5-15 parts of oleic acid, 3-10 parts of inorganic base and 10-25 parts of alcohol compound.

6. The collector according to claim 5, characterized in that The inorganic base is sodium hydroxide or potassium hydroxide; the alcohol compound is at least one of methanol, ethanol, ethylene glycol, diethylene glycol, isopropyl alcohol and glycerol; and the iodine value of the oleic acid is in the range of 90-140.

7. A method for preparing the collector according to any one of claims 5 to 6, characterized in that: The steps include: (1) Adding an inorganic alkali aqueous solution to oleic acid to prepare an oleic acid alkaline solution; (2) adding an amidated carboxylic acid compound and an alcohol compound to the alkaline oleic acid solution obtained in step (1) in sequence to obtain a mixture; (3) The mixture obtained in step (2) is sheared and stirred to mix uniformly to obtain the collector for spodumene flotation.

8. The method for preparing a collector according to claim 7, wherein In step (1), oleic acid is dissolved in an inorganic alkaline aqueous solution at 70-85° C. to prepare an oleic acid alkaline solution with a mass concentration of 60%-80%.

9. The method for preparing a collector according to claim 7, wherein: In step (2), the time interval for sequentially adding the amidated carboxylic acid compound and the alcohol compound to the oleic acid alkaline solution is 4-6 minutes; in step (3), the shear stirring time is 20-30 minutes.

10. Use of the collector according to any one of claims 5 to 6 or the collector obtained by the preparation method according to any one of claims 7 to 9 in spodumene flotation.

Images