Amidated carboxylic compounds, collectors for spodumene flotation, and methods of making and using the same

Abstract

The application belongs to the technical field of mineral processing, and discloses an amidated carboxylic compound, a collecting agent for spodumene flotation, a preparation method of the collecting agent and application of the collecting agent in spodumene flotation. The amidated carboxylic compound is obtained by the reaction of an amino acid, acyl chloride and sodium hydroxide, is resistant to acid and alkali at normal temperature, is not easy to decompose, and can improve the selectivity of the collecting agent. The collecting agent comprises 30-45 parts of the amidated carboxylic compound, 5-15 parts of oleic acid, 3-10 parts of inorganic alkali and 10-25 parts of an alcohol compound. The collecting agent has good dispersibility, foaming capacity and the ability to inhibit gangue, feldspar and quartz minerals, has good collecting effect on spodumene at room temperature, significantly improves the selectivity of the ore, ensures the concentrate grade of spodumene, improves the recovery rate, and has good application effect in spodumene flotation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal ore dressing, and particularly relates to an amidated carboxylic compound, an amidated organic carboxylic collector for spodumene flotation, a preparation method and application thereof. BACKGROUND

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

[0003] Flotation is the most widely used method of ore dressing. In the field of spodumene flotation process, high-alkali non-desliming method has been widely promoted, which greatly simplifies the flotation process. However, the selection of flotation reagents is the most important factor in high-alkali non-desliming process. Due to the lack of high-efficiency selectivity and collecting ability of traditional collectors for spodumene flotation, the development of spodumene beneficiation has been severely limited. Therefore, it is necessary to find new flotation collectors. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the deficiencies and shortcomings mentioned in the background, and to provide an amidated carboxylic compound, a preparation method and a complex application thereof for spodumene flotation, to solve the problems of low flotation index, poor low-temperature collector solubility and dispersion effect, and low concentrate grade of the lithium ore collector in the prior art.

[0005] In the field of spodumene flotation, carboxylic collectors with amide structures, in addition to increasing the carbon chain and improving the collecting performance, the amide structure has significant selectivity, which can greatly improve the concentrate grade in spodumene flotation. Therefore, by constructing carboxylic acid and amide groups in one molecular structure, high-efficiency selective flotation of spodumene minerals can be achieved. Currently, there is no report on the use of carboxylic acid group and amide group-containing compounds for spodumene mineral flotation in the prior art.

[0006] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0007] In a first aspect, the present application provides an amidated carboxylic compound, which has the following structural formula:

[0008] .

[0009] Preferably, the amide carboxylic compound is obtained by reacting amino acid, acyl chloride and sodium hydroxide, and is an anionic collector.

[0010] In a second aspect, the present application provides a preparation method of the amide carboxylic compound, comprising the following steps: stirring the amino acid with water, adding acyl chloride, sodium hydroxide and water dropwise, and obtaining the amide carboxylic compound after reaction.

[0011] The synthesis general formula of the amide carboxylic compound is as follows:

[0012] .

[0013] Preferably, in the preparation method, the amino acid is at least one of glycine, threonine, lysine and leucine; the acyl chloride is at least one of lauroyl chloride, myristoyl chloride, palmitoyl chloride and oleoyl chloride; and water is used as the reaction solvent and does not participate in the reaction.

[0014] 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 adding the acyl chloride, sodium hydroxide and water is 0-5℃, the adding time is controlled to be 30-45 min; the reaction temperature is 20-30℃, and the reaction time is 3-5 h.

[0015] In a third aspect, the present application provides a collector for spodumene flotation, which comprises 30-45 parts by weight of the amide carboxylic compound, 5-15 parts by weight of oleic acid, 3-10 parts by weight of inorganic base and 10-25 parts by weight of alcohol compound.

[0016] Preferably, the inorganic base is sodium hydroxide or potassium hydroxide.

[0017] Preferably, the alcohol compound is at least one of methanol, ethanol, ethylene glycol, diethylene glycol, isopropyl alcohol and glycerol.

[0018] Preferably, the iodine value of the oleic acid ranges from 90 to 140.

[0019] In a fourth aspect, the present application provides a preparation method of the collector, comprising the following steps:

[0020] (1) adding inorganic base aqueous solution to the oleic acid to prepare an oleic acid alkalization solution;

[0021] (2) adding the amide carboxylic compound and the alcohol compound to the oleic acid alkalization solution obtained in step (1) to obtain a mixture;

[0022] (3) Shearing and stirring the mixture obtained in step (2) to mix uniformly to obtain the collector for spodumene flotation.

[0023] The preparation method, preferably, in step (1), the oleic acid is dissolved in 70-85 DEG C inorganic liquid alkali to prepare an oleic acid alkaline solution with a mass concentration of 60%-80%.

[0024] Preferably, in step (1), the oleic acid is dissolved in 70-85 DEG C inorganic alkali aqueous solution to prepare an oleic acid alkaline solution with a mass concentration of 60%.

[0025] Preferably, in step (2), the time interval for sequentially adding the amide carboxylic compound and the alcohol compound into the oleic acid alkaline solution is 4-6 min, so as to ensure that the amide compound does not decompose in large amount in the high-temperature alkaline solution; in step (3), the shearing and stirring time is 20-30 min.

[0026] In a fifth aspect, the present application provides an application of the collector in spodumene flotation.

[0027] The collector of the present application has good collecting effect on spodumene at room temperature, ensures high recovery rate of spodumene, and improves the grade of spodumene concentrate to a certain extent and reduces the amount of the collector.

[0028] 1) The amide carboxylic compound of the present application is resistant to acid and alkali at normal temperature and is not easy to decompose, has stronger collecting capacity than the conventional oleic acid collector, and the amide bond can inhibit gangue and feldspar minerals, further improving the selectivity of the collector.

[0029] 2) The oleic acid has certain collecting effect on spodumene, has straight-chain structure, and has hydrophilic-hydrophobic balance theory, so that the carboxyl group is hydrophilic and the alpha position rear end is all-hydrocarbon structure, so that the hydrophobicity of the hydrocarbon chain of the oleic acid is stronger, and the oleic acid is more easily collected on spodumene, and after saponification, the dispersibility is stronger, and can be similar to the main component amide carboxylic acid, and the collecting performance is strengthened.

[0030] 3) The main advantage of the low-carbon chain alcohol compound of the present application is that it has a single or multiple hydroxyl groups, has strong polarity, and can well mix the oleic acid alkaline compound, the amide compound, and water with each other; at the same time, it has strong defoaming capacity, and in the flotation process, the foam cannot be eliminated to cause overflow of the flotation tank.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1. The amide carboxylic compound of the present application is resistant to acid and alkali at room temperature, is not easy to decompose, has stronger collecting ability than the conventional oleic acid collector, and the amide bond can inhibit the gangue and feldspar minerals, further improving the selectivity of the collector; the amide carboxylic acid is easy to obtain, the reaction conditions are relatively mild, and the preparation process is simple.

[0033] 2. The collector provided by the present application has good dispersibility, foaming capacity and self-inhibiting ability of gangue, feldspar and quartz minerals, has good collecting effect on spodumene at room temperature, significantly improves the selectivity of the ore, ensures the concentrate grade of spodumene, and improves the recovery rate.

[0034] 3. The preparation method of the present application is simple to operate, and the amide compound will not decompose in large quantities in the alkaline solution at high temperature. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0036] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of the amide carboxylic compound in Example 1 of the present application (H NMR). 1 H NMR).

[0037] Figure 2 is the nuclear magnetic resonance carbon spectrum of the amide carboxylic compound in Example 1 of the present application (C NMR). 13 C NMR).

[0038] Figure 3 is the FT-IR spectrum of the amide carboxylic compound in Example 1 of the present application.

[0039] Figure 4 is the flow chart of the collector in Example 2 of the present application applied to spodumene ore flotation. DETAILED DESCRIPTION

[0040] In order to facilitate the understanding of the present application, the present application will be described in more detail and carefully below in combination with the drawings of the specification and the preferred embodiments, but the protection scope of the present application is not limited to the following specific embodiments.

[0041] Unless otherwise defined, all professional terms used below have the same meaning as understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present application.

[0042] Unless otherwise specifically indicated, all raw materials, reagents, instruments and apparatuses used in the present application can be purchased on the market or prepared by existing methods.

[0043] Example 1

[0044] An amidated carboxylic acid compound, the synthetic chemical equation of which is as follows:

[0045] ;

[0046] The preparation method of the amidated carboxylic acid compound is as follows:

[0047] (1) In a three-necked flask, 0.1 mol of glycine, 50 g of water were added and stirred thoroughly;

[0048] (2) A solution of oleoyl chloride 0.1 mol, sodium hydroxide (0.22 mol) and water (25 g) was added dropwise at 5°C, and stirred thoroughly for 30 min;

[0049] (3) The reaction was carried out at 30°C for 3 h to obtain the target product amidated carboxylic acid compound.

[0050] After acidification to pH = 2 by adding dilute hydrochloric acid, its nuclear magnetic resonance spectrum (H NMR) Figures 1-2 and infrared analysis (IR) Figure 3 are as follows:

[0051] Figures 1-2 It can be seen that, 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。

[0052] FromFigure 3 It can be seen that IR (KBr), ν (cm -1 ): 3311(OH), 2922 (CH), 2850 (CH), 1699(C=O), 1645 (C=O), 1546 (NH).

[0053] The carbonyl and amino groups in the carbon NMR spectrum 13 The appearance of specific peaks at δ 174.92, 172.73 and δ 6.50 (s, 1H) in C NMR (126 MHz, CDCl3) and the appearance of two carbonyl characteristic peaks around 1699 and 1650 in the infrared spectrum indicate that the amidated carboxylic acid has been successfully synthesized. The general structural formula is R1-C(O)NHCH2-COONa, where R1 is a hydrocarbon alkane with 17 carbon atoms.

[0054] Example 2

[0055] A collector for spodumene flotation, wherein the weight ratio of each raw material is as follows: 5 parts of oleic acid with an iodine value of 140, 30 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 alkane with 17 carbon atoms), 3 parts of potassium hydroxide, and 10 parts of isopropanol.

[0056] The preparation method of the collector used for spodumene flotation in this embodiment is as follows:

[0057] (1) Dissolve oleic acid in a 50% potassium hydroxide aqueous solution at 70°C to prepare an oleic acid alkalization solution with a mass concentration of 70% (the alkali reacts with oleic acid to form oleate).

[0058] (2) Add the amidated carboxylic acid compound and isopropanol of Example 1 to the oleic acid alkalinization solution of step (1) at 5-minute intervals to obtain a mixture;

[0059] (3) Shear and stir the mixture obtained in step (2) for 20-30 minutes until it is evenly mixed to obtain a collector for spodumene flotation.

[0060] The collector prepared in this embodiment, along with existing collectors and a collector without added organic solvents, were applied to the flotation of spodumene ore with a Li₂O content of 0.43% in the feed sample. Please refer to [link to relevant documentation]. Figure 4 The flotation process shown is as follows: the modifier is 1600 g / t sodium carbonate, 800 g / t sodium hydroxide, and the activator is 80 g / t calcium chloride. The comparison results of the effects are shown in Table 1.

[0061] Table 1: Flotation Results

[0062]

[0063] From the comparison results, in the room temperature slurry, the lithium spodumene concentrate recovery rate obtained by using the collector of the embodiment is increased by about 5% and the lithium spodumene concentrate grade is increased by about 1.8% than that of the traditional sodium oleate when the collector dosage of the embodiment is lower than that of the traditional sodium oleate. In the case that the collector dosage of the embodiment is the same as that without adding the organic solvent, the concentrate grade is significantly increased after adding an appropriate amount of low alcohol (isopropyl alcohol) in the collector of the embodiment. The reason is that in the comparison test without adding low alcohol, the amount of foam is large and not easy to be eliminated in the flotation process, the non-lithium spodumene mineral impurities are easily floated, and the separation efficiency is reduced.

[0064] Embodiment 3

[0065] A collector for lithium spodumene flotation, the weight ratio of each raw material is: 5 parts of oleic acid with iodine value = 100, 40 parts of amide carboxylic compound of embodiment 1 (the structural general formula is R1-C(O)NHCH2-COONa, R1 is a carbon hydrogen alkenyl with 17 carbon atoms), 5 parts of sodium hydroxide, and 10 parts of diethylene glycol.

[0066] The preparation method of the collector for lithium spodumene flotation in the embodiment is as follows:

[0067] (1) Dissolve the oleic acid in the sodium hydroxide aqueous solution to prepare a mixed solution with a mass concentration of 70%;

[0068] (2) Add the amide carboxylic compound of the embodiment and diethylene glycol to the oleic acid alkaline solution of step (1) in turn with an interval of 5 minutes to obtain a mixture;

[0069] (3) Shear stir the mixture obtained in step (2) for 20-30 minutes to obtain a collector for lithium spodumene flotation.

[0070] The collector prepared in the embodiment and the collector of the prior art are respectively applied to the flotation of lithium spodumene ore with a grade of 0.43% Li2O. Please refer to the flotation process shown in FIG. 1: the adjusting agent is sodium carbonate 1600 g / t and sodium hydroxide 800 g / t, and the activator is calcium chloride 80 g / t. The comparison results of the use effect are shown in Table 2. Figure 4

[0071] Table 2: Flotation results

[0072]

[0073] ​The comparative results show that, in room temperature slurry with the same collector dosage, the spodumene concentrate recovery rate obtained using the collector in this embodiment is approximately 15% higher than that obtained using traditional sodium oleate, while maintaining the spodumene concentrate grade above 5%. In the comparative experiment, using a single, equal amount of an amidated carboxylic acid compound as a collector revealed poor collecting ability; it needs to be combined with oleic acid and other additives to produce a positive synergistic effect, thereby improving the spodumene recovery rate while maintaining the spodumene grade.

[0074] Comparative Example 1

[0075] Compared with Example 3, the only difference is that collector a ( Collector a was used as a collector, with an increased dosage, in the primary roughing of spodumene ore with a Li₂O grade of 0.43% in the feed sample: collector a 1000 g / t; other operations and parameters were the same as in Example 1; the experimental results are shown in Table 1. Table 1 shows that when collector a was used as the collector, the Li₂O grade in the lithium concentrate was only 4.36%, and the recovery rate was only 52.93%. These results indicate that, compared with the collector used in this invention, collector a is significantly less effective in the flotation of lower-grade spodumene ore.

[0076] Table 1: Effects of collector a in Comparative Example 1 and collector in Example 3 on spodumene flotation

[0077]

[0078] Comparative Example 2

[0079] Compared with Example 3, the only difference is that collector b (with the general structural formula R1-CONHCH2CH2OHCOONa, where R1 is a hydrocarbon chain olefin with 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 grade of 0.43% in the feed sample: 800 g / t of collector b was used; other operations and parameters were the same as in Example 1; the experimental results are shown in Table 2. As can be seen from Table 2, when collector b is used as the collector, the Li2O grade in the lithium concentrate is only 4.32%, and the recovery rate is only 65.09%. The above results show that, compared with the collector used in this invention, collector b is significantly less effective in the flotation of lower grade spodumene ore.

[0080] Table 2: Effects of collector b in Comparative Example 2 and collector in Example 3 on spodumene flotation

[0081]

Claims

1. A process for the preparation of a collector for spodumene flotation, characterized by, The raw materials include 40 parts of amide carboxylic acid compound, 5 parts of oleic acid with iodine value of 100, 5 parts of sodium hydroxide and 10 parts of diethylene glycol by weight; The preparation method of the collector comprises the following steps: dissolving oleic acid in 70-85 DEG C sodium hydroxide aqueous solution to prepare an oleic acid alkalization solution with mass concentration of 60-80%, adding amide carboxylic acid compound and alcohol compound into the oleic acid alkalization solution in sequence, controlling the time interval of addition to be 4-6 min, shearing and stirring the obtained mixture for 20-30 min, and uniformly mixing to obtain the collector for spodumene flotation; The preparation method of the amide carboxylic acid compound comprises the following steps: stirring glycine with water, adding oleoyl chloride, sodium hydroxide and water dropwise, and obtaining the amide carboxylic acid compound after reaction; the molar ratio of the glycine, the oleoyl chloride and the sodium hydroxide is 0.1-0.12:0.1-0.15:0.22-0.3, the total amount of water is 12-15 times of the mass of the glycine, the temperature of adding the oleoyl chloride, the sodium hydroxide and the water is 0-5 DEG C, the adding time is controlled to be 30-45 min, the reaction temperature is 20-30 DEG C, and the reaction time is 3-5 h.

2. Use of a collector obtained by the process according to claim 1 in the flotation of spodumene, characterized in that, The collector is applied to the flotation of spodumene raw ore Li2O, the amount of the collector is 500 g / t, the adjusting agent used is sodium carbonate 1600 g / t and sodium hydroxide 800 g / t, and the activator is calcium chloride 80 g / t.

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