Method for improving dehydration performance of flotation clean coal based on high-molecular polymer

Abstract

The invention discloses a method for improving the dehydration performance of flotation clean coal based on a high-molecular polymer, and relates to the technical field of coal slime flotation. The method comprises the following steps: S1, adding a high-molecular polymer; S2, adding a surfactant; and S3, carrying out solid-liquid separation on the flotation clean coal. According to the method, through the synergistic effect of the high-molecular polymer and the surfactant, the dewatering effect of the flotation clean coal is greatly improved, the filtering time is shortened, the production efficiency is improved, the water content of the filter cake is reduced, compared with a traditional dewatering process, the water content of the flotation clean coal filter cake can be remarkably reduced through the method, and therefore the follow-up treatment and transportation cost is reduced; the adopted high-molecular polymer and the surfactant can achieve a good effect at a low dosage, and the adopted surfactant is an environment-friendly surfactant, has biodegradability, has small influence on the environment and has good sustainability.

Description

Technical Field

[0001] The invention relates to the technical field of coal slime flotation, in particular to a method for improving the dehydration performance of flotation clean coal based on high molecular polymer. Background Art

[0002] The moisture content of the flotation clean coal produced in the coal washing process is often higher than 22% after dehydration. In the production and sales process of coal preparation plants, flotation clean coal is often blended with gravity clean coal and sold as commercial coal. Excessive moisture content of flotation clean coal will cause gravity clean coal to "backwater". In addition, the increase in moisture content of clean coal will have an adverse effect on coal processing, utilization, transportation and other links. For coking coal, for every 1.0% increase in clean coal moisture, the coking time will be extended by 10-20 minutes, the coke output will decrease by 3.0% to 4.0%, and the carbon emissions of coke ovens will increase by 2.4%;

[0003] High moisture content will affect the quality of the gelatinous layer and shorten the life of the coke oven. High moisture content will also increase the heat consumption of thermal coal during combustion and reduce the heating capacity of thermal coal. In addition, the moisture in the product coal will cause a large amount of ineffective transportation, increase transportation costs, and cause equipment or car freezing accidents in high-cold areas, affecting production or transportation.

[0004] Excessive moisture content in clean coal will also cause a decline in profits and negative impacts on downstream coal product utilization industries;

[0005] With the improvement of coal mining mechanization and the increase of coal mining depth, the proportion of fine coal particles in the mined raw coal has gradually increased, resulting in an increase in the proportion of flotation clean coal in the clean coal leaving the factory;

[0006] In the traditional dehydration process, the dehydration efficiency of flotation clean coal is low and the moisture content of the filter cake is high. The existing technology mostly uses polymer flocculants or surfactants to improve the dehydration effect, but the effect is limited when these chemical agents are used alone;

[0007] In view of the above problems, the inventors proposed a method for improving the dehydration performance of flotation clean coal based on high molecular polymer to solve the above problems. Summary of the invention

[0008] In order to solve the problem of poor dehydration performance of flotation clean coal, the purpose of the present invention is to provide a method for improving the dehydration performance of flotation clean coal based on high molecular polymer.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solution: a method for improving the dehydration performance of flotation clean coal based on high molecular polymer, comprising the following steps:

[0010] S1. Add high molecular polymer

[0011] Adding high molecular weight polymer to the flotation clean coal slurry causes coal slime particles to agglomerate;

[0012] S2. Add surfactant

[0013] Then, a surfactant is added to adjust the chemical properties of the surface of the coal slime flocs and enhance the hydrophobicity;

[0014] S3. Solid-liquid separation of flotation clean coal

[0015] The high molecular polymer and the surfactant are stirred to fully react with the slurry, and the high molecular polymer and the surfactant are used to synergistically improve the dehydration performance of the flotation clean coal, thereby promoting the solid-liquid separation of the flotation clean coal and significantly improving the solid-liquid separation efficiency of the flotation clean coal. After the high molecular polymer forms flocs in the flotation clean coal, the surfactant further changes the properties of the flotation clean coal flocs, and the hydrophobic group of the surfactant has a greater polymerization intensity with the high molecular polymer.

[0016] Preferably, in S1, the high molecular polymer is cationic polyacrylamide.

[0017] Preferably, in S2, the surfactant is a non-ionic surfactant.

[0018] Preferably, in S1, the solid content of the flotation clean coal slurry is 200 g / L.

[0019] Preferably, in S3, the stirring controls the distribution uniformity of the high molecular polymer and the surfactant, the stirring speed is 400 rpm, and the stirring time is 5 min.

[0020] Preferably, in S3, the method for synergistically improving the dehydration performance of flotation clean coal by using the high molecular polymer and the surfactant is as follows:

[0021] S31, take 15g of dry flotation clean coal sample and place it in a beaker, add pure water to 75ml according to the actual flotation clean coal concentration on site to prepare a slurry with a mass concentration of 200g / L, and stir evenly;

[0022] S32, adding high molecular polymer, stirring at a speed of 400 rpm, so that the flotation clean coal slurry forms a floc structure;

[0023] S33, after stirring for 5 min, add surfactant, stir at a speed of 400 rpm, and stir for 5 min;

[0024] S34. After the slurry preparation is completed, pour the slurry into the Buchner funnel and start filtering to measure its filtration performance.

[0025] Preferably, in S6, the filtration speed and filtration moisture are used as indicators to measure the dehydration performance of the flotation clean coal.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. In the present invention, the synergistic effect of high molecular polymer and surfactant is used to greatly improve the dehydration effect of flotation clean coal, shorten the filtration time, increase production efficiency, and reduce the moisture content of filter cake. Compared with the traditional dehydration process, the method can significantly reduce the moisture content of flotation clean coal filter cake, thereby reducing the subsequent processing and transportation costs;

[0028] 2. In the present invention, the high molecular polymer and surfactant used can achieve good effects at a relatively low dosage. The surfactant used is an environmentally friendly surfactant, which is biodegradable, has little impact on the environment, and has good sustainability;

[0029] 3. In the present invention, since the dehydration efficiency is improved, the processing time is shortened, and the water content of the filter cake is reduced, the subsequent energy consumption and operating costs are reduced, and the overall economic benefits are improved;

[0030] 4. In the present invention, no complicated equipment or operation is required, and the existing flotation equipment can be used with a little improvement, which is convenient for industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 The present invention is a flow chart of a method for improving the dehydration performance of flotation clean coal based on high molecular polymer.

[0033] Figure 2 It is a schematic diagram of improving the dehydration performance of flotation clean coal by using high molecular polymer and surfactant in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in 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.

[0035] like Figure 1-2As shown, the present invention provides a method for improving the dehydration performance of flotation clean coal based on a high molecular polymer, and the filtration rate of the flotation clean coal slurry and the moisture content of the filter cake are used as indicators to measure the dehydration performance of the flotation clean coal. The greater the filtration rate, the lower the moisture content of the filter cake, and the better the dehydration performance of the flotation clean coal. The calculation method of the filtration rate is as follows:

[0036]

[0037] v is the filtration rate, in mL / (s·m 2 );

[0038] V is the volume of filtrate when the water on the filter cake surface disappears, in ml;

[0039] t is the time for water on the filter cake surface to disappear, in seconds;

[0040] A is the cross-sectional area of ​​the filter cake under the plane, in cm 2 ;

[0041] r is the radius of the filter paper, in cm;

[0042] Embodiment 1:

[0043] Flotation clean coal dehydration performance

[0044] 1. Take 15g of dry flotation clean coal sample and place it in a beaker to prepare a slurry with a mass concentration of 200g / L, and stir evenly;

[0045] 2. Conduct Buchner funnel filtration experiment;

[0046] 3. After testing and calculation, the moisture content of the flotation clean coal filter cake is 31.48%, and the filtration rate is 353.73mL / (s·m 2 );

[0047] Effect of high molecular weight polymer on dewatering performance of flotation clean coal slurry

[0048] 1. Take 15g of dry flotation clean coal sample and place it in a beaker to prepare a slurry with a mass concentration of 200g / L;

[0049] 2. After stirring for 5 minutes, add the polymer and stir evenly;

[0050] 3. After the slurry is prepared, pour the slurry into the Buchner funnel and start filtering;

[0051] 4. After testing and calculation, the moisture content of the flotation clean coal filter cake is 25.58%, and the filtration rate is 607.51mL / (s·m 2 );

[0052] Effect of surfactant on dewatering performance of flotation clean coal slurry

[0053] 1. Take 15g of dry flotation clean coal sample and place it in a beaker to prepare a slurry with a mass concentration of 200g / L;

[0054] 2. After stirring for 5 minutes, add surfactant and stir evenly;

[0055] 3. After the slurry is prepared, pour the slurry into the Buchner funnel and start filtering;

[0056] 4. After testing and calculation, the moisture content of the flotation clean coal filter cake is 29.26%, and the filtration rate is 385.83mL / (s·m 2 );

[0057] Effect of synergistic effect of polymer and surfactant on dewatering performance of flotation clean coal slurry

[0058] 1. Take 15g of dry flotation clean coal sample and place it in a beaker to prepare a slurry with a mass concentration of 200g / L;

[0059] 2. After stirring for 5 minutes, add surfactant and stir evenly;

[0060] 3. After the slurry is prepared, pour the slurry into the Buchner funnel and start filtering;

[0061] 4. After testing and calculation, the moisture content of the flotation clean coal filter cake is 22.96%, and the filtration rate is 652.94mL / (s·m 2 ).

[0062] Embodiment 2:

[0063] Select the flotation clean coal sample, the solid content of the slurry is 20%;

[0064] 1. Addition of high molecular polymer: Add 40 g / t of high molecular polymer to 1000 mL of flotation clean coal slurry (solid content 20%), and agglomerate the coal slurry particles to form larger flocs by stirring (400 rpm, 5 min);

[0065] 2. Addition of surfactant: After adding the high molecular weight polymer, further add 800g / t of surfactant, and change the chemical properties of the floc surface by uniform stirring (400rpm, 3min) to enhance its hydrophobicity;

[0066] 3. Dehydration experiment: The treated slurry is filtered using a vacuum filter, the filtration time is recorded and the moisture content of the filter cake is measured;

[0067] Experimental results: Through the synergistic effect of high molecular polymer and surfactant, the moisture content of the flotation clean coal filter cake was reduced by about 15% and the filtration time was shortened by 20%.

[0068] Embodiment three:

[0069] Select the flotation clean coal sample, the solid content of the slurry is 15%;

[0070] 1. Addition of high molecular polymer: Add 30g / t of high molecular polymer to 1000mL of flotation clean coal slurry (solid content 15%), stir at 400rpm for 5min, and make the coal sludge particles agglomerate to form flocs;

[0071] 2. Addition of surfactant: Add 700g / t of surfactant, stirring at 400rpm for 3min, so that the surfactant is evenly distributed on the surface of the flocs;

[0072] 3. Dehydration experiment: Use a vacuum filter to dehydrate and measure the moisture content of the filter cake and the filtration time;

[0073] Experimental results: The moisture content of the treated flotation clean coal filter cake was reduced by 12% and the filtration time was shortened by 18%.

[0074] Embodiment 4:

[0075] Select flotation clean coal samples from different mining areas, the solid content of the slurry is 25%;

[0076] 1. Optimization of polymer and surfactant dosage: In this example, different dosages of polymer and surfactant combinations were tested, and the optimal combination was finally determined to be 40 g / t of polymer and 800 g / t of surfactant;

[0077] 2. Operation conditions: After adding the polymer, stir at 400 rpm for 5 min, then add the surfactant and continue stirring at 400 rpm for 3 min;

[0078] 3. Dehydration experiment: Through vacuum filtration test, record the moisture content of the filter cake and filtration time;

[0079] Experimental results: The dehydration effect of this combination is the most significant, the moisture content of the filter cake is reduced by 20% and the filtration time is shortened by 30%.

[0080] It can be seen from the four embodiments that by optimizing the synergistic effect of the high molecular polymer and the surfactant, the present invention can effectively improve the dehydration performance of the flotation clean coal under different process conditions, and the combination of different dosages, stirring speeds and times can be flexibly adjusted according to the specific slurry properties to achieve the best dehydration effect.

[0081] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for improving the dehydration performance of flotation clean coal based on high molecular polymer, characterized in that: The following steps are involved: S1. Add high molecular polymer Adding high molecular weight polymer to the flotation clean coal slurry causes coal slime particles to agglomerate; S2. Add surfactant Then, a surfactant is added to adjust the chemical properties of the surface of the coal slime flocs and enhance the hydrophobicity; S3. Solid-liquid separation of flotation clean coal The high molecular polymer and the surfactant are stirred to fully react with the slurry, and the high molecular polymer and the surfactant are used to synergistically improve the dehydration performance of the flotation clean coal, thereby promoting the solid-liquid separation of the flotation clean coal.

2. A method for improving the dehydration performance of flotation clean coal based on high molecular polymer as claimed in claim 1, characterized in that: In S1, the high molecular polymer is cationic polyacrylamide.

3. The method for improving the dehydration performance of flotation clean coal based on high molecular polymer according to claim 1, characterized in that: In S2, the surfactant is a nonionic surfactant.

4. The method for improving the dehydration performance of flotation clean coal based on high molecular polymer according to claim 1, characterized in that: In S1, the solid content of the flotation clean coal slurry is 200 g / L.

5. The method for improving the dehydration performance of flotation clean coal based on high molecular polymer according to claim 1, characterized in that: In S3, the high molecular polymer and the surfactant are fully reacted with the slurry by stirring, the stirring speed is 400 rpm, and the stirring time is 5 minutes.

6. The method for improving the dehydration performance of flotation clean coal based on high molecular polymer according to claim 1, characterized in that: In S3, the method of using the high molecular polymer and the surfactant to synergistically improve the dehydration performance of flotation clean coal is specifically as follows: S31, take 15g of dry flotation clean coal sample and place it in a beaker, add pure water to 75ml according to the actual flotation clean coal concentration on site to prepare a slurry with a mass concentration of 200g / L, and stir evenly; S32, adding high molecular polymer, stirring at a speed of 400 rpm, so that the flotation clean coal slurry forms a floc structure; S33, after stirring for 5 min, add surfactant, stir at a speed of 400 rpm, and stir for 5 min; S34. After the slurry preparation is completed, pour the slurry into the Buchner funnel and start filtering to measure its filtration performance.

7. The method for improving the dehydration performance of flotation clean coal based on high molecular polymer according to claim 1, characterized in that: In S6, the filtration rate and filtration moisture are used as indicators to measure the dehydration performance of flotation clean coal.

Images