Collecting agent for low-rank coal flotation and preparation method thereof

Abstract

The invention belongs to the technical field of coal processing, and particularly discloses a collecting agent for flotation of low-rank coal and a preparation method of the collecting agent, and the collecting agent comprises the following components in parts by weight: 20-25 parts of diesel oil, 5-10 parts of tar, 2-3 parts of an emulsifier, 3-5 parts of coconut oil, 5-10 parts of illegal cooking oil and 80-100 parts of deionized water. Compared with the prior art, the collecting agent for low-rank coal flotation is low in cost, the agents can be evenly dispersed in ore pulp in the form of tiny liquid drops, the surface tension of an oil-water interface is reduced, and collecting agent oil drops can be dispersed into smaller sizes; the coal particles can be better attached to bubbles in the flotation process, and the method has the obvious advantages in the aspects of the clean coal yield and the clean coal ash content.

Description

Technical Field

[0001] The present invention relates to the technical field of coal processing, and particularly to a collector for low-rank coal flotation and a preparation method thereof. Background Art

[0002] In the coal processing industry, flotation technology is a commonly used method for coal ash separation and purification. However, for low-rank coal, traditional flotation methods and flotation reagents often have certain problems. Since low-rank coal usually contains a large amount of ash and fine-grained gangue minerals, it is difficult for traditional flotation methods and flotation reagents to effectively separate and purify it, and at the same time, a large amount of reagent is wasted. Specifically, the following difficulties exist in the flotation separation of low-rank coal at present: (1) The ash content of the pulp entering the flotation increases sharply, and mineral impurities are likely to contaminate the clean coal product through ways such as covering, entrainment, and carrying; (2) Low-rank coal mainly has a large amount of fine-grained gangue minerals doped in coal particles, and its specific surface area is large, resulting in poor flotation selectivity, and a large amount of reagent is consumed during the traditional flotation process. The above factors lead to low flotation recovery rate of high-ash fine-grained difficult-to-float coal and serious fluctuations in the quality of clean coal products, restricting the efficient flotation of low-rank coal.

[0003] Therefore, in view of the characteristics of difficult flotation of low-rank coal, it is urgent to develop a new collector for low-rank coal flotation. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a collector for low-rank coal flotation and a preparation method thereof.

[0005] To achieve the above object, the present invention is implemented according to the following technical scheme:

[0006] The first technical solution provided by the present invention is a collector for low-rank coal flotation, which is composed of the following components in parts by weight:

[0007] 20-25 parts of diesel oil, 5-10 parts of tar, 2-3 parts of emulsifier, 3-5 parts of coconut oil, 5-10 parts of waste oil, and 80-100 parts of deionized water.

[0008] Preferably, the emulsifier is alkyl polyglycoside APG.

[0009] The second technical solution provided by the present invention is a preparation method of a collector for low-rank coal flotation, including the following steps:

[0010] S1. First, the raw materials are processed. The waste oil is put into a test tube and centrifuged for 5 minutes, and the supernatant is taken and filtered through a filter paper to obtain the processed waste oil;

[0011] S2. Add 20 - 25 parts of diesel into a beaker, then add 5 - 10 parts of tar, 5 - 10 parts of filtered gutter oil, 3 - 5 parts of coconut oil, 2 - 3 parts of emulsifier, and 80 - 100 parts of deionized water. Place a magnetic rotor in the beaker, seal the beaker with plastic wrap, and process it by heating in a water bath while stirring. After 30 minutes, use an ultrasonic instrument for ultrasonic treatment to obtain a collector for low - rank coal flotation.

[0012] Preferably, in step S2, the temperature of the water - bath heating is 45 °C and the stirring speed is 1800 r / min.

[0013] Preferably, in step S2, the ultrasonic power of the ultrasonic treatment is 120 w and the time is 5 min.

[0014] Compared with the prior art, the collector for low - rank coal flotation of the present invention has a low cost, can make these agents uniformly disperse in the pulp in the form of tiny droplets, reduces the surface tension of the oil - water interface, and enables the collector oil droplets to be dispersed into smaller sizes.

[0015] The collector for low - rank coal flotation of the present invention is more likely to adsorb on the surface of coal particles. The improvement of its dispersibility makes the concentration of the agent around the coal particles more uniform, which is beneficial for the adsorption of the collector molecules on the active sites on the surface of the coal particles. Due to the small size of the tiny droplets of the emulsified agent, they can more effectively fill the tiny pores and depressions on the surface of the coal particles, making the contact between the agent and the coal particles more sufficient.

[0016] The collector for low - rank coal flotation of the present invention may also change the adsorption mode of the agent on the surface of the coal particles. The polar group of alkyl polyglycoside APG can undergo chemical adsorption with the functional groups (such as oxygen - containing functional groups) on the surface of the coal particles, while the non - polar group extends outwards, further enhancing the hydrophobicity of the coal particle surface. This adsorption mode is more firm than simple physical adsorption and can better make the coal particles adhere to the bubbles during the flotation process, showing obvious advantages in both the yield of clean coal and the ash content of clean coal. Detailed Embodiments

[0017] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further details the present invention with reference to embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0018] Example 1

[0019] First, process the raw materials. Put the gutter oil into a test tube and centrifuge for 5 minutes, take the supernatant, and filter it with filter paper to obtain the processed gutter oil.

[0020] Then, add 20 kg of diesel into a beaker, then add 5 kg of tar, 5 kg of filtered gutter oil, 3 - 5 kg of coconut oil, 2 - 3 kg of alkyl polyglycoside APG, and 80 kg of deionized water. Place a magnetic rotor in the beaker, seal the beaker with plastic wrap, and process it by heating in a water bath while stirring. The temperature of the water bath heating is 45 °C, the stirring speed is 1800 r / min. After 30 minutes, use an ultrasonic instrument to perform ultrasonic treatment for 5 minutes at an ultrasonic power of 120 w to obtain a collector for low - rank coal flotation.

[0021] Example 2

[0022] First, treat the raw materials. Put the gutter oil into a test tube and centrifuge for 5 minutes, take the supernatant, and filter it with filter paper to obtain the treated gutter oil.

[0023] Then, add 20 - 25 kg of diesel into a beaker, then add 10 kg of tar, 10 kg of filtered gutter oil, 5 kg of coconut oil, 3 kg of alkyl polyglycoside APG, and 100 kg of deionized water. Place a magnetic rotor in the beaker, seal the beaker with plastic wrap, and process it by heating in a water bath while stirring. The temperature of the water bath heating is 45 °C, the stirring speed is 1800 r / min. After 30 minutes, use an ultrasonic instrument to perform ultrasonic treatment for 5 minutes at an ultrasonic power of 120 w to obtain a collector for low - rank coal flotation.

[0024] Example 3

[0025] First, treat the raw materials. Put the gutter oil into a test tube and centrifuge for 5 minutes, take the supernatant, and filter it with filter paper to obtain the treated gutter oil.

[0026] Then, add 22 kg of diesel into a beaker, then add 8 kg of tar, 7 kg of filtered gutter oil, 4 kg of coconut oil, 2.5 kg of alkyl polyglycoside APG, and 90 kg of deionized water. Place a magnetic rotor in the beaker, seal the beaker with plastic wrap, and process it by heating in a water bath while stirring. The temperature of the water bath heating is 45 °C, the stirring speed is 1800 r / min. After 30 minutes, use an ultrasonic instrument to perform ultrasonic treatment for 5 minutes at an ultrasonic power of 120 w to obtain a collector for low - rank coal flotation.

[0027] Comparative Example 1

[0028] Use commercially available single diesel as the collector.

[0029] Comparative Example 2

[0030] Use commercially available single emulsified diesel as the collector.

[0031] Comparative Example 3

[0032] Use commercially available emulsified diesel oil added with gutter oil as a collector.

[0033] Comparative Example 4

[0034] Use commercially available emulsified diesel oil added with tar as a collector.

[0035] Comparative Example 5

[0036] Use commercially available emulsified diesel oil added with tar and gutter oil as a collector.

[0037] Use the collectors prepared in Example 3 and Comparative Examples 1 - 5 in equal amounts to prepare ultra-clean coal from low-ash bituminous coal. The specific operation process is as follows:

[0038] 1) Crush raw bituminous coal with an ash content of 13.7 wt% into particles with a particle size of less than 1 mm, and send it into a ball mill for grinding for 20 min to fully dissociate the coal and minerals, obtaining raw coal particles with a particle size of less than 200 mesh. The proximate analysis and ultimate analysis of the raw coal are shown in Table 1.

[0039] Table 1

[0040]

[0041]

[0042] 2) Add the raw coal particles to a pulp mixing and stirring tank, add water to adjust the pulp to obtain a pulp with a concentration of 40 - 80 g / L. Add 2000 g of collector and 800 g of foaming agent No. 2 oil per ton of coal pulp, and mix and stir for 3 min. After pulp adjustment, the pulp enters a flotation machine for flotation. During flotation, the rotation speed of the flotation machine is 2000 rad / min, the air inflow rate of the flotation machine is 200 L / h, and the scraping time of the foam is 3 min; clean coal and tail coal are obtained. Filter and dry the obtained clean coal, and measure the yield and ash content of the clean coal.

[0043] The specific process for measuring the ash content of the clean coal is as follows:

[0044] Gradually send the ash dish containing the clean coal from outside the furnace into a muffle furnace preheated to 815 ± 10 °C for ashing and burning until the mass is constant. Take the percentage of the mass of the residue in the mass of the coal sample as the ash yield; the calculation formula is as follows

[0045] Aad = (m1 / m) × 100;

[0046] Where: Aad—the ash yield of the air-dried coal sample, %;

[0047] m1—the mass of the residue, g;

[0048] m—the mass of the coal sample, g.

[0049] The flotation result data of this embodiment are shown in Table 1.

[0050] Table 1

[0051]

[0052] As can be seen from Table 1, the collector of the present invention can better make coal particles adhere to bubbles during the flotation process, and has obvious advantages in both the yield of clean coal and the ash content of clean coal.

[0053] The technical solution of the present invention is not limited to the limitations of the above specific embodiments. Any technical deformation made according to the technical solution of the present invention falls within the protection scope of the present invention.

Claims

1. A collector for low-rank coal flotation, characterized in that, It consists of the following components in parts by weight: 20 - 25 parts of diesel, 5 - 10 parts of tar, 2 - 3 parts of emulsifier, 3 - 5 parts of coconut oil, 5 - 10 parts of gutter oil, 80 - 100 parts of deionized water.

2. The collector for low-rank coal flotation according to claim 1, characterized in that, The emulsifier is alkyl polyglycoside APG.

3. A preparation method of a collector for low-rank coal flotation as described in claim 1 or 2, characterized in that, It includes the following steps: S1. First, treat the raw materials. Put the gutter oil into a test tube and centrifuge for 5 minutes. Take the supernatant and filter it with filter paper to obtain the treated gutter oil. S2. Add 20 - 25 parts of diesel into a beaker, then add 5 - 10 parts of tar, 5 - 10 parts of the filtered gutter oil, 3 - 5 parts of coconut oil, 2 - 3 parts of emulsifier, and 80 - 100 parts of deionized water. Place a magnetic rotor in the beaker, seal the beaker with plastic wrap, and treat it by heating in a water bath while stirring. After 30 minutes, use an ultrasonic instrument for ultrasonic treatment to obtain a collector for low - rank coal flotation.

4. The preparation method of the collector for low-rank coal flotation according to claim 3, characterized in that, In step S2, the temperature of the water - bath heating is 45 °C, and the stirring speed is 1800 r / min.

5. The preparation method of the collector for low-rank coal flotation according to claim 3, characterized in that, In step S2, the ultrasonic power of the ultrasonic treatment is 120 w, and the time is 5 min.

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