A microemulsion type coal flotation collector based on dynamic covalent bond and a preparation method and application thereof

Abstract

The application belongs to the technical field of floatation reagent, and provides a microemulsion type coal floatation collector based on dynamic covalent bond and a preparation method and application thereof.The collector is composed of the following components: 20-40 parts of hydrocarbon oil collector, 8-20 parts of emulsifier, 22-60 parts of water, and 0.5-2 parts of alkali.The emulsifier of the microemulsion type coal floatation collector is composed of a conventional non-ionic surfactant and an anionic surfactant based on dynamic covalent bond, and has excellent emulsifying performance.The average droplet size of the prepared microemulsion is less than 100 nm, and can still be maintained at the nanometer level after being diluted by 1-100 times of water, and has a higher specific surface area compared with the conventional emulsion type collector.In the coal floatation process, the contact probability of the collector oil droplet and the coal particle can be significantly improved, the floatation effect is improved, and the consumption of the collector is reduced.

Description

Technical Field

[0001] This invention belongs to the field of flotation reagent technology, specifically relating to a microemulsion coal flotation collector based on dynamic covalent bonds, its preparation method, and its application. Background Technology

[0002] Flotation is a separation method based on the differences in the physicochemical properties of the interface between valuable minerals and useless gangue. Flotation reagents play a significant role in controlling the interfacial properties between coal and mineral impurities, increasing the flotation rate, enhancing the selective recovery of coal particles, and improving the flotation effect.

[0003] Hydrocarbon oil collectors such as kerosene and light diesel oil are the most commonly used in flotation. However, due to their hydrophobic nature, they have poor dispersibility in water and cannot form fine dispersed phases. Emulsification involves dispersing two immiscible liquids to form a stable emulsion over a certain period. Extensive theoretical and practical experience has demonstrated that the smaller the oil droplets dispersed in the slurry by hydrocarbon oil collectors, the larger their specific surface area. A greater number of oil droplets increases the probability of contact between the droplets and coal particles, making it easier to form an oil film on the hydrophobic coal particles. This results in better flotation performance and also helps reduce the amount of collector required.

[0004] However, currently, the hydrocarbon oil collectors are usually forcibly dispersed in the coal slurry by mechanical stirring. This results in large and few collector droplets, which have a low probability of colliding with coal particles. Furthermore, the formed droplets will aggregate in large quantities in a short period of time, causing a considerable portion of the collector to fail to function and be discharged with the tailings. This reduces the efficiency of the collector and increases the cost of subsequent coal slurry water treatment. Summary of the Invention

[0005] To improve the emulsification effect of hydrocarbon oil collectors and reduce the droplet size of emulsions, this invention provides a microemulsion-type coal flotation collector based on dynamic covalent bonds, its preparation method, and its application. The microemulsion-type coal flotation collector is prepared using a hydrocarbon oil collector as the oil phase and a solution containing an emulsifier as the aqueous phase. The emulsifier simultaneously contains conventional nonionic surfactants and anionic surfactants formed based on dynamic covalent bonds, resulting in a synergistic effect that significantly improves the oil-water emulsification effect and facilitates microemulsion formation. Furthermore, even after dilution with water 1-100 times, it remains at the nanoscale, exhibiting a higher specific surface area compared to conventional emulsion-type collectors. During coal flotation, it significantly increases the contact probability between collector oil droplets and coal particles, improving flotation efficiency while reducing the amount of collector required.

[0006] This invention is achieved through the following technical solution:

[0007] A microemulsion coal flotation collector based on dynamic covalent bonds, comprising, by weight, 20-40 parts hydrocarbon oil collector, 8-20 parts emulsifier, 22-60 parts water, and 0.5-2 parts alkali.

[0008] The emulsifier is a combination of nonionic and anionic surfactants, with a mass ratio of (0.5-5):1.

[0009] The nonionic surfactant is lauryl glucoside, sorbitol fatty acid ester, polyoxyethylene octylphenol ether-10, sorbitol monooleate polyoxyethylene ether, or fatty alcohol polyoxyethylene ether.

[0010] The anionic surfactant is spontaneously formed by the formation of dynamic covalent bonds between an aromatic aldehyde and a primary amine under alkaline conditions. The aromatic aldehyde is either p-hydroxybenzaldehyde or p-carboxybenzaldehyde; the primary amine is either n-hexylamine or n-octylamine.

[0011] The hydrocarbon oil collector is any one or a mixture of kerosene, diesel, and gasoline.

[0012] The alkali mentioned includes sodium hydroxide, potassium hydroxide, or sodium carbonate.

[0013] A method for preparing a microemulsion coal flotation collector based on dynamic covalent bonds, comprising the following steps:

[0014] Add 20-40 parts of hydrocarbon oil collector, 8-20 parts of emulsifier, 22-60 parts of water, and 0.5-2 parts of alkali to a container in that order, and stir at 50-200 r / min for 5-30 min until a homogeneous microemulsion is obtained. This is the microemulsion coal flotation collector based on dynamic covalent bonds.

[0015] The microemulsion-type coal flotation collector based on dynamic covalent bonds obtained in this invention can be diluted 1-100 times with water according to factors such as pulp concentration and coal host phase composition during actual coal flotation applications. The average droplet size of the microemulsion remains at the nanometer level, demonstrating excellent coal flotation performance and broad application prospects. The beneficial effects of this invention are as follows:

[0016] (1) The microemulsion coal flotation collector based on dynamic covalent bonds of the present invention is a homogeneous microemulsion with long-term stability; and the average droplet size is less than 100 nm, which has a higher specific surface area than traditional emulsion collectors. In the coal flotation process, it can significantly increase the contact probability between the collector oil droplets and coal particles, and more easily form an oil film on the surface of hydrophobic coal particles, thereby improving the flotation effect.

[0017] (2) The microemulsion coal flotation collector based on dynamic covalent bonds prepared in this invention can still maintain the nanoscale after being diluted 1-100 times with water, exhibiting excellent emulsification effect. The dilution ratio can be selected according to the flotation conditions, which helps to reduce the amount of collector used and lower the cost of flotation reagents while improving the flotation effect.

[0018] (3) The emulsifier involved in this invention includes anionic surfactants based on dynamic chemical bonds, which can spontaneously generate in an alkaline environment and spontaneously break down in an acidic environment, thus avoiding complex synthesis processes and preparation costs. Its flexible pH control can effectively solve the cost problem of subsequent coal slurry water treatment, which is conducive to the industrial-scale application of coal flotation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the formation principle of anionic surfactants based on dynamic chemical bonds.

[0020] Figure 2 This image shows the macroscopic morphology and particle size distribution of a microemulsion coal flotation collector based on dynamic covalent bonds. Detailed Implementation

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0022] Example 1

[0023] Take 32 parts of hydrocarbon oil collector (kerosene), 50 parts of water, 8 parts of lauryl glucoside, 4.8 parts of p-hydroxybenzaldehyde, 4 parts of n-hexylamine, and 1.2 parts of sodium hydroxide. Mix the above components and stir at 100 r / min for 5 min until the mixture is homogeneous to obtain a microemulsion coal flotation collector based on dynamic covalent bonds.

[0024] Taking the microemulsion coal flotation collector based on dynamic covalent bonds constructed in Example 1 as an example, using p-hydroxybenzaldehyde and n-hexylamine as raw materials, the principle of forming anionic surfactant based on dynamic chemical bonds is shown in the diagram below. Figure 1 As shown.

[0025] The macroscopic morphology and particle size distribution curves of the microemulsion coal flotation collector are shown in the figure. Figure 2 As shown in the figure, the obtained microemulsion has a uniform and transparent appearance, a median particle size of approximately 10 nm, and exhibits long-term stability.

[0026] Example 2

[0027] Take 32 parts of hydrocarbon oil collector (diesel), 50 parts of water, 8 parts of lauryl glucoside, 4.8 parts of p-hydroxybenzaldehyde, 4 parts of n-hexylamine, and 1.2 parts of sodium hydroxide. Mix the above components and stir at 100 r / min for 5 min until homogeneous to obtain a microemulsion coal flotation collector based on dynamic covalent bonds. The median particle size of the microemulsion coal flotation collector obtained in Example 2, as determined by a nanoparticle size analyzer, is approximately 20 nm.

[0028] Example 3

[0029] Take 25 parts of hydrocarbon oil collector (diesel), 55 parts of water, 10 parts of lauryl glucoside, 4.8 parts of p-hydroxybenzaldehyde, 4 parts of n-hexylamine, and 1.2 parts of sodium hydroxide. Mix the above components and stir at 100 r / min for 5 min until homogeneous to obtain a microemulsion coal flotation collector based on dynamic covalent bonds. The median particle size of the microemulsion coal flotation collector obtained in Example 3, as determined by a nanoparticle size analyzer, is approximately 8 nm.

[0030] Example 4

[0031] The coal flotation experiment was conducted using the microemulsion-type coal flotation collector based on dynamic covalent bonds prepared in this invention, including the following steps:

[0032] The concentration of the coal slurry to be floated was adjusted to 80 g / L. A microemulsion coal flotation collector was added, and after stirring and mixing thoroughly, the mixture was allowed to stand for 2 minutes. Then, a frother was added, and the mixture was stirred and mixed thoroughly. After standing for 30 seconds, aeration flotation was performed. The aeration rate was 0.2 m³ / s. 3 / (m 2 The stirring speed is 2000 r / min, and the flotation time is about 5 min.

[0033] It should be noted that the raw coal used in the test was crushed, screened, blended, and reduced in size to prepare analytical coal samples with a particle size of less than 0.5 mm according to the "Methods for Preparing Coal Samples" (GB474-1984). The test methods followed the "Laboratory Unit Flotation Test Methods for Coal Preparation" (GB4758-1984) for performance testing, with a pulp concentration of 80 g / L, a flotation machine stirring speed of 2000 r / min, and an aeration rate of 0.2 m³ / min. 3 / (m 2 The flotation time is 5 minutes, and the reagent dosage is 600 g / t.

[0034] It should be further noted that in the experiment, Comparative Example 1 used conventional flotation reagent diesel oil at a dosage of 600 g / t and frother 120 g / t.

[0035] The specific test results are shown in Table 1.

[0036] Table 1. Performance Test Results

[0037]

[0038] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Although the specific embodiments of the present invention have been described above, they are not intended to limit the protection scope of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A microemulsion coal flotation collector based on dynamic covalent bonds, characterized in that, By weight, it consists of the following components: 20-40 parts hydrocarbon oil collector, 8-20 parts emulsifier, 22-60 parts water, and 0.5-2 parts alkali. The hydrocarbon oil collector is any one or a mixture of kerosene, diesel, and gasoline; The emulsifier is a combination of nonionic surfactant and anionic surfactant, and the mass ratio of nonionic surfactant to anionic surfactant is (0.5-5):1; The nonionic surfactant is lauryl glucoside, sorbitol fatty acid ester, polyoxyethylene octylphenol ether-10, sorbitol monooleate polyoxyethylene ether, or fatty alcohol polyoxyethylene ether. The anionic surfactant is spontaneously formed by p-hydroxybenzaldehyde and n-hexylamine under alkaline conditions through the formation of dynamic covalent bonds; The microemulsion coal flotation collector is a homogeneous microemulsion with an average droplet size of less than 100 nm, and can still maintain the nanoscale after being diluted 1-100 times with water.

2. The microemulsion coal flotation collector based on dynamic covalent bonds as described in claim 1, characterized in that, The alkali mentioned is sodium hydroxide, potassium hydroxide, or sodium carbonate.

3. The method for preparing the microemulsion coal flotation collector based on dynamic covalent bonds as described in any one of claims 1 to 2, characterized in that, The steps are as follows: Add 20-40 parts of hydrocarbon oil collector, 8-20 parts of emulsifier, 22-60 parts of water, and 0.5-2 parts of alkali to a container in that order, and stir at 50-200 r / min for 5-30 min until a homogeneous microemulsion is obtained. This is the microemulsion coal flotation collector based on dynamic covalent bonds.

4. The use of the microemulsion coal flotation collector based on dynamic covalent bonds as described in claim 1 for coal flotation.

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