Hydroximic acid-quaternary ammonium salt ionic liquid collecting agent and preparation method and application thereof

Abstract

The invention discloses a hydroximic acid-quaternary ammonium salt ionic liquid collecting agent and a preparation method and application thereof. The structural formula of the hydroximic acid-quaternary ammonium salt ionic liquid collecting agent is as shown in the formula (I): # imgabs0 # (I). Compared with a traditional salicylhydroxamic acid collecting agent, the hydroxamic acid-quaternary ammonium salt ionic liquid collecting agent has good collecting performance and selectivity on rare earth ore, a good collecting effect can still be achieved under the condition that a foaming agent is not added, and the hydroxamic acid-quaternary ammonium salt ionic liquid collecting agent has wide application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing agents, and in particular relates to a hydroxamic acid-quaternary ammonium salt ionic liquid collector and a preparation method and application thereof. Background Art

[0002] Rare earths are known as "industrial vitamins" and are strategic elements for the development of high-tech. They are widely used in electronics, petrochemicals, metallurgy, machinery, energy, light industry, environmental protection, agriculture, and national defense industries. Bastcerium is currently the main mineral source for extracting rare earth elements, and flotation is the main method for enriching and recovering bastcerium in industry. Common collectors used for flotation of rare earth minerals include carboxylates (fatty acids), isohydroxamates, and some organic phosphoric acids. Because bastcerium has similar surface properties and floatability to calcium-containing minerals such as fluorite, the flotation separation of rare earth ores faces problems such as low selectivity and sensitivity to impurity ions.

[0003] Ionic liquids are liquid molten salt systems composed entirely of organic cations and organic or inorganic anions at room temperature or near room temperature. They are called green solvents because of their low melting point, high boiling point, good solubility, high thermal and chemical stability, almost no volatility and low toxicity.

[0004] Since ionic liquids have the characteristics of strong design ability, low vapor pressure, non-flammability, and basically non-volatility, the required ionic liquids can be synthesized in a targeted manner. Ionic liquids are widely used and have rapidly expanded from the initial green chemical and chemical fields to the functional materials and energy fields. However, there are currently few related applications in the flotation field, and there are widespread problems of flotation agent pollution and high energy consumption in the flotation field of my country's mineral processing industry. Perhaps replacing traditional flotation agents with ionic liquids can achieve the upgrading and major innovation of traditional flotation. Therefore, the application of ionic liquids in flotation is of great significance to alleviating the pollution of flotation agents in my country and the upgrading of traditional flotation agents. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a hydroxamic acid-quaternary ammonium salt ionic liquid collector and a preparation method and application thereof, so as to solve the technical problems of low collectivity and selectivity of traditional flotation agents for rare earth ore flotation separation.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions: The present invention provides a hydroxamic acid-quaternary ammonium salt ionic liquid collector, the structural formula of which is shown in formula (I): (I).

[0007] The present invention also provides a method for preparing a hydroxamic acid-quaternary ammonium salt ionic liquid collector, comprising the following steps: S1. mixing salicylic acid hydroxamate and tetrabutylammonium halide in a solvent to obtain a first mixed solution; S2. mechanically mixing the first mixed solution at 20 to 30° C. to obtain a second mixed solution; S3. performing solid-liquid separation on the second mixed solution to obtain a product solution; S4. Removing the solvent from the product solution to obtain a hydroxamic acid-quaternary ammonium salt ionic liquid collector.

[0008] Preferably, in step S1, the molar ratio of salicylic hydroxamate to tetrabutylammonium halide is (2:3) to (3:2).

[0009] Preferably, in step S1, the salicylic acid salt is one or more of sodium salicylic acid and potassium salicylic acid; the tetrabutylammonium halide is one or more of tetrabutylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium iodide.

[0010] Preferably, in step S1, the solvent is one or more of methanol, ethanol and propanol.

[0011] Preferably, in step S2, the mechanical mixing method is magnetic stirring, and the magnetic stirring time is 18 to 24 hours.

[0012] Preferably, in step S3, after the solid-liquid separation, the precipitate is washed with a solvent, and then the filtrate is mixed with the washing liquid to obtain a product solution.

[0013] Preferably, after step S4, the method further comprises: S5. vacuum drying the product obtained in step S4 to obtain a hydroxamic acid-quaternary ammonium salt ionic liquid collector; the vacuum drying temperature is 30-50°C.

[0014] The present invention also provides an application of the hydroxamic acid-quaternary ammonium salt ionic liquid collector in mineral flotation.

[0015] Preferably, the above-mentioned minerals are rare earth minerals, including the useful mineral bastnaesite and the gangue mineral fluorite.

[0016] The beneficial effects of the present invention are: The hydroxamic acid-quaternary ammonium salt ionic liquid collector provided by the invention has good collecting property and selectivity for rare earth ores, can achieve good collecting effect without adding a foaming agent, and has a simple preparation process and is easy to operate.

[0017] The hydroxamic acid-quaternary ammonium salt ionic liquid collector provided by the present invention is neutral, while salicylic hydroxamic acid is acidic. In comparison, the flotation process of this reagent may produce fewer harmful byproducts, which is more beneficial to subsequent wastewater treatment and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0019] Figure 1 This is the infrared spectrum of the tetrabutylammonium salicylate hydroxamate ionic liquid of Example 1. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1 In a 100 mL beaker, add 50 mL of deionized water as the reaction solvent, add 1.54 g (0.01 mol) of salicylic acid and 1.06 g (0.01 mol) of sodium carbonate, stir at room temperature until completely dissolved, then heat and evaporate the water to obtain 1.706 g (0.00974 mol) of sodium salicylic acid, with a yield of 97.4%. Take another 100mL beaker, add 30mL (0.50mol) of anhydrous ethanol as the reaction solvent, add 0.175g (0.001mol) of sodium salicylate and 0.278g (0.001mol) of tetrabutylammonium chloride, place the beaker in a magnetic stirrer and stir at a constant temperature (25°C) for 20 hours, filter and wash the resulting reaction solution with anhydrous ethanol to remove the sodium chloride generated by the reaction, let the resulting product solution stand for 10 hours after washing, and finally heat in a water bath at 100°C to evaporate the ethanol solvent to obtain a brown liquid, which is the target product. Then, the target product is vacuum dried in a vacuum drying oven at 50°C to obtain tetrabutylammonium salicylate (TS).

[0022] The obtained product was characterized by infrared spectroscopy. Figure 1 As shown. From the infrared spectrum of the collector, we can see that: 3396cm -1 The -OH stretching vibration peaks on the benzene ring are at 1773, 1383 and 1030 cm -1 The peaks at 1462 and 1486 cm-1 are the stretching vibration peaks of C=O, CN and NO in the hydroxamic acid group. -1 The characteristic absorption peaks of quaternary ammonium salt of collector are at 2962, 2875 and 1631 cm -1 The stretching vibration peaks of CH in -CH3 and -CH2- reflect the structural characteristics of methyl-type cationic surfactants; therefore, it can be confirmed through infrared spectroscopy that the synthesized product is the target product, tetrabutylammonium salicylic acid hydroxamate ionic liquid.

[0023] The hydroxamic acid-quaternary ammonium salt ionic liquid collector prepared in Example 1 was used for the flotation of pure bastcerium ore and pure fluorite ore, respectively. The pure bastcerium ore came from the Yaniuping rare earth mine in Sichuan, and the pure fluorite ore came from Hubei Province. The chemical composition analysis thereof is shown in Table 1 and Table 2, respectively.

[0024] The salicylic acid-quaternary ammonium salt ionic liquid prepared in Example 1 was prepared into 25×10 -3 mol / L solution, and add the reagent into the 50mL flotation cell of XFGCⅡ5-35g laboratory aerated hanging cell flotation machine according to a certain proportion, so that the concentration of the reagent in the flotation cell is 0.1×10 -3 mol / L,0.2×10 -3 mol / L,0.3×10 -3 mol / L,0.4×10 - 3 mol / L,0.5×10 -3 mol / L,0.6×10 -3 mol / L; that is, different concentrations of collector solutions were prepared in the flotation cell. Weigh 3.0g of pure fluorocarbon cerium ore and place it in the flotation cell with different concentrations of collectors mentioned above and keep the pulp concentration at 6%. Set the stirring speed to 1800 rpm at room temperature 25°C and stir for 3 minutes. Use NaOH or HCl to adjust the pH to 9 and mix the pulp at 1800 rpm for 3 minutes. Then add the foaming agent MIBC and keep its concentration in the flotation cell at 20mg / L. Stir for 1 minute and then float for 4 minutes. The foam product and the product in the cell were dried and weighed to calculate the recovery rate. The same method as above was used to obtain the effect of collector concentration on the recovery rate of pure fluorite ore. The results are shown in Table 3. It can be seen that the mineral recovery rate increases with the increase of the reagent concentration. The collector concentration is 0.3×10 -3 mol / L, the recovery rate of the useful mineral fluorocarbon cerium ore has reached more than 90%. At this time, the recovery rate of the useful mineral fluorocarbon cerium ore and the gangue mineral fluorite differs by 36.38%. Increasing the collector concentration, the recovery rate has little trend of improvement. Considering the factors of reagent economy and environmental impact, the optimal concentration of the collector is 0.3×10 -3 mol / L. Afterwards, the pH condition experiment was carried out under the optimal concentration condition, and the pH values ​​were set to 3.5, 4.5, 6, 7.5, 9, 10.5, and 12 respectively. The recovery rates are shown in Table 4. It was found that at a concentration of 0.3×10 -3 mol / L, pH = 9, the recovery rate of bastnaesite can reach 90.18%, while the recovery rate of fluorite is 53.80%. Under this condition, flotation separation of bastnaesite and fluorite can be achieved.

[0025] Table 1 Chemical composition analysis results of bastnaesite (%)

[0026] Table 2 Chemical composition analysis results of fluorite ore (%)

[0027] Table 3 Effect of collector concentration on pure mineral recovery rate (mol / L)

[0028] Table 4 Effect of pH value on recovery rate of pure minerals (mol / L)

[0029] The hydroxamic acid-quaternary ammonium salt ionic liquid and salicylic hydroxamic acid prepared in Example 1 were used to flotation a mixed ore of bastnaesite and fluorite. Specifically: Weigh 3.0g of artificial binary mixed mineral, in which the mass ratio of bastnaesite to fluorite is 1:1. -3 mol / L, pH=9, add frother MIBC and keep its concentration in the flotation tank at 20mg / L for flotation, and obtain the grade (in terms of rare earth oxide REO) and recovery rate of fluorocarbon cerium ore as shown in Table 5. According to Table 5, it can be seen that the grade of fluorocarbon cerium ore in the obtained concentrate is 61.01% when the collector provided by the present invention is used for flotation of mixed ore, which is higher than 45.26% when salicylic acid is used, and the recovery rate of fluorocarbon cerium ore is 90.27%, which is also higher than 77.03% when salicylic acid is used. In the case of no inhibitor, the sorting performance of salicylic acid is obviously inferior to that of the synthetic agent of the present invention.

[0030] Table 5 Flotation index of artificial mixed ore

[0031] Example 2 In a 100mL beaker, 60mL (1.00mol) of anhydrous ethanol was used as the reaction solvent, 0.350g (0.002mol) of sodium salicylate and 0.556g (0.002mol) of tetrabutylammonium chloride were added, and the beaker was placed in a magnetic stirrer and stirred at a constant temperature (25°C) for 24 hours. The resulting reaction solution was filtered and washed with anhydrous ethanol to remove the sodium chloride generated by the reaction. After washing, the resulting product solution was allowed to stand for 9h, and finally heated in a water bath at 100°C to evaporate the ethanol solvent, and a brown liquid was obtained, which was the target product. The target product was then vacuum dried in a vacuum drying oven at 50°C to obtain tetrabutylammonium salicylate (TS).

[0032] According to the same method as Example 1, the hydroxamic acid-quaternary ammonium salt ionic liquid collector prepared in Example 2 was used for the flotation of pure bastnaesite and pure fluorite, respectively, and the indicators in Tables 6 and 7 were obtained. It can be seen from Tables 6 and 7 that when the collector prepared in Example 2 was used for the flotation of the mineral, the collector concentration was 0.3×10 -3 mol / L, the recovery rate of the useful mineral bastnaesite is high, and the recovery rate of the useful mineral bastnaesite and the gangue mineral fluorite is 34.92%. The best flotation conditions are consistent with those obtained in Example 1, and the optimal concentration is 0.3×10 -3 mol / L, pH=9.

[0033] Table 6 Effect of collector concentration on pure mineral recovery (mol / L)

[0034] Table 7 Effect of pH value on recovery rate of pure minerals (mol / L)

[0035] At the same time, according to the same beneficiation method as Example 1, the hydroxamic acid-quaternary ammonium salt ionic liquid collector prepared in Example 2 and salicylic hydroxamic acid are used to flotate fluorocarbon cerium ore and fluorite mixed ore respectively. The flotation results are shown in Table 8. According to Table 8, it can be seen that the grade of fluorocarbon cerium ore in the obtained concentrate is 59.67%, which is higher than 46.54% when salicylic hydroxamic acid is used, and the recovery rate of fluorocarbon cerium ore is 92.04%, which is also higher than 71.55% when salicylic hydroxamic acid is used. In the case of no inhibitor, the sorting performance of salicylic hydroxamic acid is obviously not as good as the synthetic agent of the present invention.

[0036] Table 8 Flotation index of artificial mixed ore

[0037] Comparative Example 1 In a 100mL beaker, 30mL (0.50mol) of anhydrous ethanol was used as the reaction solvent, 0.159g (0.001mol) of sodium benzohydroxamate and 0.278g (0.001mol) of tetrabutylammonium chloride were added, and the beaker was placed in a magnetic stirrer and stirred at a constant temperature (25°C) for 20 hours. The resulting reaction solution was filtered and washed with anhydrous ethanol to remove the sodium chloride generated by the reaction. After washing, the resulting product solution was allowed to stand for 10 hours, and finally heated in a water bath at 100°C to evaporate the ethanol solvent. The target product was then vacuum dried in a vacuum drying oven at 50°C to obtain a benzohydroxamic acid-quaternary ammonium salt ionic liquid.

[0038] According to the same method as Example 1, the benzohydroxamic acid-quaternary ammonium salt ionic liquid prepared in Comparative Example 1 was used for the flotation of pure fluorocarbon cerium ore and pure fluorite ore, respectively, and the indicators in Tables 9 and 10 were obtained. It can be seen from Tables 9 and 10 that the recovery rate of fluorite under various concentration conditions of the benzohydroxamic acid-quaternary ammonium salt ionic liquid prepared in Comparative Example 1 was higher than that of fluorocarbon cerium ore, and the concentration was 0.6×10 -3 mol / L, the recovery rate of the useful mineral fluorocarbon cerium ore was only 73.07%. The benzohydroxamic acid-quaternary ammonium salt ionic liquid prepared in Comparative Example 1 had a worse collection effect on fluorocarbon cerium ore than the salicylic acid-quaternary ammonium salt ionic liquid prepared in Example 1. Since the present invention explores a reagent with a better collection effect on rare earth minerals (such as fluorocarbon cerium ore), there is no need to conduct mixed ore flotation experiments.

[0039] Table 9 Effect of collector concentration on pure mineral recovery (mol / L)

[0040] Table 10 Effect of pH value on recovery rate of pure minerals (mol / L)

[0041] Example 3 According to the ore dressing method basically the same as that in Example 1, the hydroxamic acid-quaternary ammonium salt ionic liquid collector and salicylic hydroxamic acid prepared in Example 1 were used to flotation pure bastnaesite ore (pH=9), except that whether or not to add a frother was used as an experimental variable, and the comparative results shown in Table 11 were obtained.

[0042] Table 11 Effect of collector type on pure mineral recovery rate of bastnaesite

[0043] As can be seen from Table 11, when only salicylic acid collector is added without using a frother, salicylic acid has basically no collection effect on bastnaesite, and the recovery rate of bastnaesite is significantly lower than that of using a frother. However, the recovery rate of bastnaesite using the ionic liquid collector of the present invention is similar to that without using a frother, and still has a good collection effect, indicating that the collector provided by the present invention can simplify the flotation reagent system and reduce costs.

[0044] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0045] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A hydroxamic acid-quaternary ammonium salt ionic liquid collector, characterized in that: Its structural formula is shown in formula (I): （Ⅰ）。 2. A method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 1, characterized in that: The following steps are involved: S1. mixing salicylic acid hydroxamate and tetrabutylammonium halide in a solvent to obtain a first mixed solution; S2. The first mixed solution is mechanically mixed at 20 to 30 ° C to obtain a second mixed solution; S3. The second mixed solution is subjected to solid-liquid separation to obtain a product solution; S4. removing the solvent in the product solution to obtain the hydroxamic acid-quaternary ammonium salt ionic liquid collector.

3. The method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 2, characterized in that: In step S1, the molar ratio of the salicylic hydroxamate to the tetrabutylammonium halide is (2:3) to (3:2).

4. The method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 2, characterized in that: In step S1, the salicylic acid hydroxamate is one or more of sodium salicylic acid hydroxamate and potassium salicylic acid hydroxamate; the tetrabutylammonium halide is one or more of tetrabutylammonium chloride, tetrabutylammonium bromide and tetrabutylammonium iodide.

5. The method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 2, characterized in that: In step S1, the solvent is one or more of methanol, ethanol, and propanol.

6. The method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 2, characterized in that: In step S2, the mechanical mixing method is magnetic stirring, and the magnetic stirring time is 18 to 24 hours.

7. The method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 2, characterized in that: In step S3, after the solid-liquid separation, the precipitate is washed with a solvent, and then the filtrate is mixed with the washing liquid to obtain the product solution.

8. The method for preparing the hydroxamic acid-quaternary ammonium salt ionic liquid collector according to claim 2, characterized in that: After step S4, the method further includes: S5. vacuum drying the product obtained in step S4 to obtain a hydroxamic acid-quaternary ammonium salt ionic liquid collector; the vacuum drying temperature is 30-50°C.

9. Use of the hydroxamic acid-quaternary ammonium salt ionic liquid collector as claimed in claim 1 in mineral flotation.

10. The use according to claim 9, characterized in that: The mineral is a rare earth mineral.

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