Asymmetric Gemini quaternary ammonium salt compound collecting agent and preparation method and application thereof

Abstract

The invention discloses an asymmetric Gemini quaternary ammonium salt compound collecting agent and a preparation method and application thereof, and belongs to the technical field of coal flotation. The asymmetric Gemini quaternary ammonium salt compound type collecting agent comprises the following components: 600 to 800 [mu] L of kerosene, 0.05 to 0.2 g of asymmetric Gemini quaternary ammonium salt, 40 to 60 g of water, and 10 to 50 [mu] L of methyl isobutyl carbinol. According to the asymmetric Gemini quaternary ammonium salt compound collecting agent, the synergistic flotation effect is achieved through agent combination, the surface property of fine-grain low-rank coal can be effectively improved, and the flotation recovery rate is increased. The asymmetric Gemini quaternary ammonium salt compound collecting agent is easy to prepare and convenient to use, and meanwhile the defects that traditional diesel oil and kerosene collecting agents are large in agent consumption, high in environmental pollution risk, low in carbon recovery rate and the like are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of coal flotation, and specifically relates to an asymmetric Gemini quaternary ammonium salt compound collector and a preparation method and application thereof. Background Art

[0002] With the continuous development and utilization of high-quality coal and the improvement of the mechanization of coal mining, the output of fine-grained low-rank coal has increased year by year. At the same time, the addition of a large amount of gangue has led to an increase in impurity minerals in fine-grained low-rank coal, seriously affecting the quality of coal products. The most widely used technology for sorting and improving the quality of fine-grained low-rank coal is froth flotation. Currently, about 90% of coal washing plants are equipped with froth flotation workshops, and the proportion of fine-grained coal processed is increasing year by year. The flotation collector is a key factor affecting the flotation effect. Traditional non-polar hydrocarbon oil collectors are insoluble in water, have poor dispersion ability in the slurry, and have low adsorption efficiency, resulting in high reagent consumption and low flotation yield during the flotation of fine-grained low-rank coal.

[0003] Asymmetric Gemini quaternary ammonium salt cationic surfactants have the advantages of high water solubility and strong surface activity. The amphiphilic structure makes it easier for directional adsorption to occur on the coal surface, forming a directional adsorption layer with non-polar groups facing the gas and polar groups facing the solid. Its asymmetry reduces its intermolecular forces and increases its adsorption capacity. Its excellent emulsifying properties also make it possible to effectively reduce the particle size of kerosene and improve its dispersibility during the compounding process. Therefore, the effect of surface modification of low-rank coal with asymmetric Gemini quaternary ammonium salt cationic surfactants is better, which is of great significance to the coal flotation industry. Such research has not been reported. Summary of the invention

[0004] In view of this, the purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide an asymmetric Gemini quaternary ammonium salt compound collector for flotation of fine-grained low-rank coal and its preparation method and application. The asymmetric Gemini quaternary ammonium salt compound collector of the present invention can realize economical and efficient flotation of fine-grained low-rank coal, and solve the problems of low efficiency, poor economy, and high pollution risk of flotation of fine-grained low-rank coal by existing flotation reagents.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An asymmetric Gemini quaternary ammonium salt composite collector comprises the following components: 600-800 μL of kerosene, 0.05-0.2 g of an asymmetric Gemini quaternary ammonium salt, 40-60 g of water, and 10-50 μL of methyl isobutyl carbinol.

[0007] In the above-mentioned asymmetric Gemini quaternary ammonium salt composite collector, the asymmetric Gemini quaternary ammonium salt surfactant has a special structure, the hydrophilic group combines with the oxygen-containing functional groups on the surface of low-rank coal, and the hydrophobic tail chains of different lengths are arranged in a directional manner and adsorbed on the surface of low-rank coal, which increases the hydrophobic groups of fine-grained low-rank coal, and the low-rank coal particles are more likely to adhere to the foam surface and the floatability is enhanced, thereby improving the separation efficiency of low-rank coal particles. The asymmetric Gemini quaternary ammonium salt surfactant has excellent emulsifying properties, and kerosene is emulsified into smaller droplets, which is conducive to its dispersion in the slurry and spreading on the surface of low-rank coal particles. At the same time, methyl isobutyl carbinol and asymmetric Gemini quaternary ammonium salt can play a synergistic adsorption role, saving the amount of reagents while increasing the output rate of clean coal.

[0008] Furthermore, the asymmetric Gemini quaternary ammonium salt is one of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, ethylene octyl dimethyl decanyl dimethyl ammonium chloride, and ethylene octyl dimethyl octadecyl dimethyl ammonium chloride.

[0009] A method for preparing the above-mentioned asymmetric Gemini quaternary ammonium salt composite collector comprises the following steps: dissolving the asymmetric Gemini quaternary ammonium salt in water, adding methyl isobutyl carbinol, mixing, and then adding kerosene, mixing, so as to obtain the asymmetric Gemini quaternary ammonium salt composite collector.

[0010] An application of the asymmetric Gemini quaternary ammonium salt composite collector as described above in the flotation of fine-grained low-rank coal.

[0011] Furthermore, the application specifically includes: adding fine-grained low-rank coal into water to form a flotation slurry, and then adding a frother and an asymmetric Gemini quaternary ammonium salt compound collector to perform flotation treatment.

[0012] Furthermore, the fine-grained low-rank coal has a particle size of 200-140 meshes accounting for 55-85% of the total mass of the material.

[0013] Furthermore, the mass concentration of the flotation pulp is 60-80 g / L.

[0014] Furthermore, the addition amount of the asymmetric Gemini quaternary ammonium salt composite collector is 250-350 kg / t.

[0015] Furthermore, the foaming agent is octanol, and the addition amount is 60-100g / t.

[0016] Furthermore, the flotation treatment time is 4 minutes.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The asymmetric Gemini quaternary ammonium salt composite collector of the present invention exerts a synergistic flotation effect through the combination of reagents, which can effectively improve the surface properties of fine-grained low-rank coal and improve the flotation recovery rate. Among them, the hydrophilic group in the asymmetric Gemini quaternary ammonium salt surfactant is more likely to combine with the oxygen-containing functional groups on the surface of the low-rank coal particles, and it is difficult to combine with the surface groups of the impurity minerals. The hydrophobic tail chain of the asymmetric Gemini quaternary ammonium salt surfactant increases its adsorption amount on the surface of the coal particles due to its structure of different lengths. At the same time, the asymmetric Gemini quaternary ammonium salt surfactant has a certain emulsification effect, which makes the droplet volume of kerosene in the slurry smaller, and the foaming ability of methyl isobutyl carbinol can increase the foam in the slurry and increase the stability. The multiple synergistic effects improve the sorting efficiency of fine-grained low-rank coal and impurity minerals.

[0019] (2) Compared with traditional hydrocarbon collectors, the asymmetric Gemini quaternary ammonium salt composite collector of the present invention releases more heat when adsorbed on the surface of fine-grained low-rank coal, so the adsorption on the surface of fine-grained low-rank coal is more intense, which reduces the number of hydrophilic functional groups on the surface of fine-grained low-rank coal and increases the number of hydrophobic functional groups, thereby enhancing the adhesion of fine-grained low-rank coal to foam, making the clean coal part more likely to float out during the flotation process. The asymmetric Gemini quaternary ammonium salt composite collector of the present invention can effectively improve the dispersion effect of traditional non-polar hydrocarbon oil collectors in water and reduce the particle size of oil droplets. At the same time, a certain dose of asymmetric Gemini quaternary ammonium salt surfactant will increase the adsorption amount compared with single chain and symmetric chain, and has a stronger effect on the modification of coal surface and a better flotation effect.

[0020] (3) Compared with the traditional kerosene collector, the flotation recovery rate of fine-grained low-rank coal was increased by 29.14% and the ash content was reduced by 1.19% by using the asymmetric Gemini quaternary ammonium salt composite collector of the present invention for flotation of fine-grained low-rank coal, thereby achieving economical and efficient flotation of fine-grained low-rank coal and overcoming the disadvantages of traditional diesel and kerosene collectors such as large reagent consumption, high environmental pollution risk, and low carbon recovery rate. DETAILED DESCRIPTION

[0021] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0022] Example 1

[0023] An asymmetric Gemini quaternary ammonium salt composite collector comprises the following components: 0.67 ml of kerosene, 0.5 g of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, 49.5 g of water, and 0.01 ml of methyl isobutyl carbinol.

[0024] The preparation method of the above-mentioned asymmetric Gemini quaternary ammonium salt composite collector is as follows:

[0025] (1) Take 0.5 g of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, add 49.5 g of ultrapure water, mix in a 100 ml beaker, then use a pipette to measure 0.01 ml of methyl isobutyl methanol and add it, place in an ultrasonic cleaning machine, ultrasonic frequency 40 kHz, ultrasonic time about 5 min, mix well.

[0026] (2) Take 25 g of the mixed solution obtained in step (1) into a 50 ml centrifuge tube, add 0.67 ml of kerosene to mix, put it into an ultrasonic wave with an ultrasonic frequency of 40 kHz and mix it for 10 min. After taking it out, put it on a 50 r / min rotary oscillator and mix it for 30 min to obtain the asymmetric Gemini quaternary ammonium salt composite collector.

[0027] Example 2

[0028] An asymmetric Gemini quaternary ammonium salt composite collector comprises the following components: 0.67 ml of kerosene, 0.5 g of ethylene octyl dimethyl decanyl dimethyl ammonium chloride, 49.5 g of water, and 0.01 ml of methyl isobutyl carbinol.

[0029] The preparation method of the above-mentioned asymmetric Gemini quaternary ammonium salt composite collector is the same as that in Example 1.

[0030] Example 3

[0031] An asymmetric Gemini quaternary ammonium salt composite collector comprises the following components: 0.67 ml of kerosene, 0.5 g of ethylene octyl dimethyl octadecyl dimethyl ammonium chloride, 49.5 g of water, and 0.01 ml of methyl isobutyl carbinol.

[0032] The preparation method of the above-mentioned asymmetric Gemini quaternary ammonium salt composite collector is the same as that in Example 1.

[0033] Comparative Example 1

[0034] A flotation collector comprises the following components: 0.5 g of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, 49.5 g of water, and 0.01 ml of methyl isobutyl carbinol.

[0035] The preparation method of the above flotation collector is as follows:

[0036] Take 0.5 g of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, add 49.5 g of ultrapure water, mix in a 100 ml beaker, then use a pipette to measure 0.01 ml of methyl isobutyl methanol and add it thereto, place in an ultrasonic cleaning machine, ultrasonic frequency 40 kHz, ultrasonic time about 5 min, mix well, and the flotation collector is obtained.

[0037] Comparative Example 2

[0038] A flotation collector comprises the following components: 0.67 ml of kerosene, 0.5 g of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, and 49.5 g of water.

[0039] The preparation method of the above flotation collector is as follows:

[0040] (1) Take 0.5 g of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, add 49.5 g of ultrapure water, mix in a 100 ml beaker, place in an ultrasonic cleaning machine, ultrasonic frequency 40 kHz, ultrasonic time about 5 min, mix well;

[0041] (2) 25 g of the mixed solution obtained in step (1) was placed in a 50 ml centrifuge tube, 0.67 ml of kerosene was added, and the mixture was placed in an ultrasonic immersion tube at an ultrasonic frequency of 40 kHz for 10 min. After being taken out, the mixture was placed in a rotary oscillator at 50 r / min for 30 min to obtain the flotation collector.

[0042] Comparative Example 3

[0043] A flotation collector comprises the following components: 0.67 ml of kerosene, 49.5 g of water, and 0.01 ml of methyl isobutyl carbinol.

[0044] The preparation method of the above flotation collector is as follows:

[0045] (1) Take 49.5 g of ultrapure water in a 100 ml beaker, and then use a pipette to measure 0.01 ml of methyl isobutyl carbinol and add it to the beaker. Place it in an ultrasonic cleaning machine, set the ultrasonic frequency to 40 kHz, and the ultrasonic time to about 5 min, and mix well.

[0046] (2) 25 g of the mixed solution obtained in step (1) was placed in a 50 ml centrifuge tube, 0.67 ml of kerosene was added, and the mixture was placed in an ultrasonic immersion tube at an ultrasonic frequency of 40 kHz for 10 min. After being taken out, the mixture was placed in a rotary oscillator at 50 r / min for 30 min to obtain the flotation collector.

[0047] Fine-grained low-rank coal (-0.50 mm particle size, ash content 21.7%, particle size 200-140 mesh accounting for 67.72% of the total mass of the material) was adjusted with water to form a flotation slurry with a mass concentration of 80 g / L, and a frother (octanol, added in an amount of 80 g / t) and the collector prepared in the above Examples 1-3 and Comparative Examples 1-3 (added in an amount of 300 kg / t) were added to carry out a flotation treatment. The flotation time was 4 minutes, and the flotation results are shown in Table 1.

[0048] Table 1 Flotation results of fine low-rank coal by collectors prepared in Examples 1-3 and Comparative Examples 1-3

[0049]

[0050] The above description is only for better explaining the embodiments of the present invention, and is not intended to limit the present invention. Any modification or equivalent substitution that does not depart from the spirit and scope of the present invention shall fall within the scope of the present invention.

Claims

1. An asymmetric Gemini quaternary ammonium salt composite collector, characterized in that: The method comprises the following components: 600-800 μL of kerosene, 0.05-0.2 g of asymmetric Gemini quaternary ammonium salt, 40-60 g of water, and 10-50 μL of methyl isobutyl methanol.

2. The asymmetric Gemini quaternary ammonium salt composite collector according to claim 1, characterized in that: The asymmetric Gemini quaternary ammonium salt is one of ethylene octyl dimethyl tetradecyl dimethyl ammonium chloride, ethylene octyl dimethyl decanyl dimethyl ammonium chloride, and ethylene octyl dimethyl octadecyl dimethyl ammonium chloride.

3. A method for preparing an asymmetric Gemini quaternary ammonium salt composite collector according to claim 1 or 2, characterized in that: The method comprises the following steps: dissolving an asymmetric Gemini quaternary ammonium salt in water, adding methyl isobutyl carbinol, mixing evenly, and then adding kerosene, mixing evenly, so as to obtain the asymmetric Gemini quaternary ammonium salt composite collector.

4. Use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 1 or 2 in the flotation of fine-grained low-rank coal.

5. The use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 4, characterized in that, The application specifically includes: adding fine-grained low-rank coal into water to form a flotation pulp, and then adding a frother and an asymmetric Gemini quaternary ammonium salt compound collector to perform flotation treatment.

6. The use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 5, characterized in that: The fine-grained low-rank coal has a particle size of 200-140 meshes, which accounts for 55-85% of the total mass of the material.

7. The use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 5, characterized in that: The mass concentration of the flotation pulp is 60-80 g / L.

8. The use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 5, characterized in that: The addition amount of the asymmetric Gemini quaternary ammonium salt composite collector is 250-350 kg / t.

9. The use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 5, characterized in that: The foaming agent is octanol, and the addition amount is 60-100g / t.

10. The use of the asymmetric Gemini quaternary ammonium salt composite collector according to claim 5, characterized in that: The flotation treatment time is 4 minutes.

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