High-oil-water-ratio type composite coal dust suppressant based on waste engine oil as well as preparation method and application of high-oil-water-ratio type composite coal dust suppressant
By using a high oil-water-based composite coal dust suppressor based on waste engine oil in the dust suppressor, the problem of reverse caused by excessive oil ratio is solved, the stability and use of the dust suppressor is achieved, the good dust suppression effect is ensured, and the production cost is reduced.
Patent Information
- Application Number
- CN202510081729.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-20
- Publication Date
- 2025-06-06
AI Technical Summary
When the oil ratio in existing dust inhibitors is too high, the reverse is likely to occur, resulting in the oil-in-water emulsion becoming a water-in-oil emulsion, which is difficult to dilute and use.
Using a high oil-water ratio composite coal dust suppressor based on waste engine oil, a stable emulsion is formed by mixing waste engine oil with a surfactant and mixing water with the second surfactant, binder and water retention agent, thereby overcoming the reverse problem caused by excessive oil ratio.
The stability and useability of dust inhibitors are achieved, good dust inhibition effects are ensured, production costs are reduced, and environmental pollution is reduced.
Smart Images
Figure CN120098605A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of dust removal, and in particular to a high oil-water ratio composite coal dust suppressant based on waste engine oil, and a preparation method and application thereof. Background Art
[0002] China is a country with abundant coal resources, so the mining and transportation of coal is of vital importance. However, during the mining and transportation of coal, dust is easily generated, which is extremely harmful to the life and health of workers. In addition, the dust generated will also pollute the ecology and environment.
[0003] In order to solve the above problems, efficient dust suppression is the main means. Common dust suppression methods include spraying water mist, covering with physical dustproof cloth, etc. However, the above methods have significant disadvantages. The effective dust suppression time of spraying water mist is too short and difficult to maintain for a long time. If high-frequency spraying is required to achieve a good dust suppression effect, it not only increases labor costs, but also causes a certain degree of waste of water resources. Although physical dustproof cloth covering can save labor costs to a certain extent, the dust suppression effect is poor and cannot effectively control the dust problem. Therefore, the development of low-cost and high-efficiency dust suppressants has extremely strong practical significance.
[0004] Waste engine oil refers to a mixed waste of waste engine oil and various additives generated during the use and maintenance of various automobiles, industrial equipment, ships, etc. my country produces tens of millions of tons of waste engine oil each year. If it cannot be effectively treated and directly discharged, it will cause great harm to the ecological environment. The effective use of waste engine oil can significantly improve environmental pollution and other conditions. Therefore, the development of waste utilization of waste engine oil has practical significance. Waste engine oil is cheap and has the characteristics of high calorific value. In the process of developing coal dust suppressants, low-cost and high-efficiency dust suppression can be achieved. However, in actual applications, when the proportion of oil phase in the oil-water mixture is too high, phase inversion is very likely to occur, turning the water-in-oil emulsion into an oil-in-water emulsion. After the phase inversion occurs, the oil-in-water emulsion cannot be diluted and is difficult to use in spraying. Summary of the invention
[0005] Based on this, the present invention provides a biomass-based composite coal dust suppressant and its preparation method and application, so as to solve the technical problem in the prior art that the oil phase ratio in the dust suppressant is too high, resulting in phase inversion, turning the water-in-oil emulsion into an oil-in-water emulsion, which is difficult to use in spraying.
[0006] The technical solution of the present invention to solve the above technical problems is as follows:
[0007] A method for preparing a high oil-water ratio composite coal dust suppressant based on waste engine oil comprises the following steps:
[0008] S10. Prepare the materials by weighing the following parts by weight: 18 to 25 parts of waste oil, 1.2 to 2.4 parts of a first surfactant, 3.3 to 7.1 parts of a second surfactant, 30 parts of water, 0.96 to 1.83 parts of a binder, and 1.2 to 3 parts of a water retaining agent;
[0009] S20. The waste oil is mixed with the first surfactant and stirred to obtain a first emulsion;
[0010] S30. Mix the water with the second surfactant, binder, and water retaining agent at 60° C. to 85° C. and stir evenly to obtain a second emulsion.
[0011] S40. Mix the first emulsion and the second emulsion, and stir them at a rotation speed of 2000 r / min to 3500 r / min for 1 min to 8 min until they are evenly mixed to obtain an emulsion with a pH of 7 to 9, i.e., a high oil-water ratio composite coal dust suppressant based on waste engine oil.
[0012] Preferably, in the above preparation method, the first surfactant includes any one of span60, fatty acid monoglyceride, span85, sorbitan sesquioleate, span65, polyoxyethylene monostearate, span20, monostearate glyceryl, span80, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, lauric acid, tween80, AEO-9, AEO-7, and tetraethylene glycol monolaurate.
[0013] Preferably, in the above preparation method, when the first surfactant is Span65, the second surfactant is a mixture of AEO-7 and AEO-9; when the first surfactant is Span80 or Span20, the second surfactant is a mixture of any two of AEO-7, Tween80 and AEO-9.
[0014] Preferably, in the above preparation method, the second surfactant is a mixture of Tween 80 and AEO-9, and the mass ratio of Tween 80 to AEO-9 is (1.5 to 4.1):(1.5 to 3).
[0015] Preferably, in the above preparation method, the binder includes any three of sodium polyacrylate, guar gum, xanthan gum, galactomannan, sodium carboxymethyl cellulose, sodium alginate, gum arabic, carrageenan, arabinose, donkey-hide gelatin, and pectin.
[0016] Preferably, in the above preparation method, the binder includes sodium carboxymethyl cellulose, xanthan gum and sodium polyacrylate, and the mass ratio of the sodium carboxymethyl cellulose, xanthan gum and sodium polyacrylate is (0.08 to 0.18):(0.08 to 0.15):(0.8 to 1.5).
[0017] Preferably, the water-retaining agent in the above preparation method includes any one of alkyl glycoside, hydroxypropyl methylcellulose, polyethylene glycol, glycerol, triethanolamine, hyaluronic acid, carboxymethyl chitosan, sodium carboxymethyl cellulose, cetyltrimethylammonium chloride, and sodium lignin sulfonate.
[0018] A high oil-water ratio composite coal dust suppressant based on waste engine oil is prepared by the preparation method of the high oil-water ratio composite coal dust suppressant based on waste engine oil.
[0019] An application of the above-mentioned high oil-to-water ratio composite coal dust suppressant based on waste engine oil to suppress dust in an area where coal dust is to be treated.
[0020] Preferably, the use of the above-mentioned high oil-water ratio composite coal dust suppressant based on waste oil comprises the following steps:
[0021] The high oil-water ratio composite coal dust suppressant based on waste oil is diluted with water in proportion and sprayed directly on the coal dust treatment area. The spraying volume is 5L / m 3 Up to 11L / m 3 ; Wherein, the coal dust to be treated area includes at least one of a coal transport vehicle, a coal mine and a coal yard.
[0022] Compared with the prior art, the present invention has at least the following advantages:
[0023] The high oil-water ratio composite coal dust suppressant based on waste engine oil disclosed in the present application (hereinafter referred to as dust suppressant) includes 18 to 25 parts of waste engine oil, 1.2 to 2.4 parts of a first surfactant, 3.3 to 7.1 parts of a second surfactant, 30 parts of water, 0.96 to 1.83 parts of a binder, and 1.2 to 3 parts of a water retainer. It is prepared by the following method: firstly, the waste engine oil and the first surfactant are mixed and stirred evenly to obtain a first emulsion; then, the water is mixed and stirred evenly with the second surfactant, the binder, and the water retainer at 60°C to 85°C to obtain a first emulsion; then, the first emulsion and the first emulsion are mixed, and stirred at a speed of 2000r / min to 3500r / min for 1min to 8min until they are evenly mixed to obtain an emulsion with a pH of 7 to 9, that is, a high oil-water ratio composite coal dust suppressant based on waste engine oil. The dust suppressant of this scheme adds a large amount of waste engine oil on the basis of ensuring a good dust suppression effect, and overcomes the problem that when the oil phase ratio is too high, phase inversion is easy to occur, turning into an oil-in-water emulsion, making it impossible to dilute and use as a dust suppressant for spraying. In addition, a large amount of waste engine oil is used in the preparation process, combined with the advantages of low cost and high combustion calorific value of waste engine oil. Not only can it ensure a good dust suppression effect, but it will not affect the calorific value of coal after spraying. It can also significantly reduce the production cost of high oil-water ratio composite coal dust suppressants, reduce the pollution caused by direct discharge of waste engine oil to the environment, and demonstrate the concept of green chemistry for environmental protection.
[0024] The dust suppressant disclosed in the present application can achieve a good dust suppression effect by diluting it with water in a certain proportion when used. Experiments show that when the dust suppressant is diluted with water in a ratio of 1:10, the viscosity can reach 128.6mpa.s, and the solidified layer acting on the sample coal also reaches an average of 13mm-14mm, and the average wind erosion rate is only 0.29%. Compared with the national railway industry standard (Type II: the dust suppressant is diluted with water in a ratio of 1:10, the viscosity in the railway industry standard is greater than 50mpa.s; the wind erosion rate is less than 1%; the thickness of the solidified layer is greater than 10mm), the viscosity is increased by 157.2%, the thickness of the solidified layer is increased by 30% to 40%, and the average wind erosion rate is reduced by 71%, which is significantly better than the railway industry standard. It shows that the dust suppressant of the present application has significantly better performance indicators than the national standard on the basis of adding a large amount of waste oil, which not only reduces the production cost but also has a good use effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0026] Figure 1 This is a scanning electron microscope image of water sprayed on lignite.
[0027] Figure 2 This is a scanning electron microscope image of water sprayed on bituminous coal.
[0028] Figure 3 This is a scanning electron microscope image of a composite coal dust suppressant based on waste oil and high oil-water ratio diluted with water at a ratio of 1:10 and sprayed on lignite.
[0029] Figure 4 This is a scanning electron microscope image of a composite coal dust suppressant based on waste oil and high oil-water ratio diluted with water at a ratio of 1:10 and sprayed on bituminous coal. DETAILED DESCRIPTION
[0030] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application 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 disclosure of the present application more thoroughly and comprehensively understood.
[0031] It should be noted that when a device is considered to be "connected" to another device, it may be directly connected to the other device or there may be an intermediate device at the same time. The terms "inside", "top", "upper", "lower", "upper", "lower" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.
[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0033] In one specific embodiment of the present invention, a method for preparing a high oil-water ratio composite coal dust suppressant based on waste engine oil comprises the following steps:
[0034] S10. Prepare the materials by weighing the following parts by weight: 18 to 25 parts of waste oil, 1.2 to 2.4 parts of a first surfactant, 3.3 to 7.1 parts of a second surfactant, 30 parts of water, 0.96 to 1.83 parts of a binder, and 1.2 to 3 parts of a water retaining agent;
[0035] In the present application, the first surfactant is preferably an oil-soluble surfactant, and the second surfactant is preferably a water-soluble surfactant. The first surfactant and the second surfactant are used in combination. On the one hand, they play an emulsifying role, so that oil and water form a stable emulsion, and on the other hand, they also have the effect of wetting coal dust, which helps the emulsion to wrap the coal dust. Preferably, the first surfactant includes any one of span60, fatty acid monoglyceride, span85, dehydrated sorbitan sesquioleate, span65, polyoxyethylene monostearate, span20, monostearate glyceride, span80, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, lauric acid, tween80, AEO-9, AEO-7, and tetraethylene glycol monolaurate. Further, when the first surfactant is span65, the second surfactant is a mixture of AEO-7 and AEO-9; when the first surfactant is span80 or span20, the second surfactant is a mixture of any two of AEO-7, Tween80 and AEO-9. Furthermore, the second surfactant is a mixture of Tween 80 and AEO-9, and the mass ratio of Tween 80 to AEO-9 is (1.5 to 4.1):(1.5 to 3).
[0036] The binder can improve the bonding performance of the dust suppressant, so that the dust suppressant forms a stable solidified layer on the surface of the coal dust, thereby having the performance of preventing water evaporation, and effectively suppressing the secondary dusting of the coal dust. In the present application, the binder includes any three of sodium polyacrylate, guar gum, xanthan gum, galactomannan, sodium carboxymethyl cellulose, sodium alginate, gum arabic, carrageenan, arabinose, donkey-hide gelatin, and pectin. Further, the binder includes sodium carboxymethyl cellulose, xanthan gum and sodium polyacrylate, and the mass ratio of the sodium carboxymethyl cellulose, xanthan gum and sodium polyacrylate is (0.08 to 0.18): (0.08 to 0.15): (0.8 to 1.5).
[0037] The water retaining agent mainly plays a moisturizing role, so that the coal dust retains a certain amount of moisture, and has a certain hygroscopic effect, so that the dust suppressant can better wet the coal dust, that is, by wetting the coal dust, the density of the coal dust is increased, and the coal dust is accelerated to fall, thereby suppressing the coal dust. In the present application, the water retaining agent includes any one of alkyl glycoside, hydroxypropyl methylcellulose, polyethylene glycol, glycerol, triethanolamine, hyaluronic acid, carboxymethyl chitosan, sodium carboxymethyl cellulose, hexadecyl trimethyl ammonium chloride, and sodium lignin sulfonate.
[0038] Through the synergistic effect of the above components, a large amount of waste engine oil is added on the basis of ensuring a good dust suppression effect, and the problem that when the oil phase ratio is too high, it is easy to undergo phase inversion and become an oil-in-water emulsion, making it impossible to dilute and use it as a dust suppressant for spraying is overcome. The large amount of waste engine oil, combined with the advantages of low cost and high combustion calorific value of waste engine oil, can not only ensure a good dust suppression effect, but also does not affect the calorific value of coal after spraying. It can also significantly reduce the production cost of dust suppressants and reduce the pollution caused to the environment by direct discharge of waste engine oil.
[0039] S20. The waste oil is mixed with the first surfactant and stirred to obtain a first emulsion;
[0040] S30. The water and the second surfactant, binder, and water retaining agent are mixed and stirred at 60°C to 85°C to obtain a second emulsion;
[0041] S40. Mix the first emulsion and the first emulsion, stir at a rotation speed of 2000 r / min to 3500 r / min for 1 min to 8 min, until they are evenly mixed to obtain an emulsion with a pH of 7 to 9, i.e., a high oil-water ratio composite coal dust suppressant based on waste engine oil.
[0042] For example, 18 to 25 parts of waste engine oil are mixed with 1.2 to 2.4 parts of a surfactant and stirred evenly to obtain a first emulsion; then 30 parts of water are mixed with 3.3 to 7.1 parts of a second surfactant, 0.96 to 1.83 parts of a binder, and 1.2 to 3 parts of a water retaining agent at 60°C to 85°C and stirred evenly to obtain a second emulsion; finally, the first emulsion and the second emulsion are mixed and stirred at a speed of 2000 r / min to 3500 r / min for 1 min to 8 min until they are evenly mixed to obtain an emulsion with a pH of 7 to 9, that is, a high oil-water ratio composite coal dust suppressant based on waste engine oil.
[0043] In another specific embodiment of the present invention, a high oil-water ratio composite coal dust suppressant based on waste engine oil is prepared by the above-mentioned preparation method of the high oil-water ratio composite coal dust suppressant based on waste engine oil. Further, the pH of the high oil-water ratio composite coal dust suppressant based on waste engine oil is 7 to 9.
[0044] In another specific embodiment of the present invention, a high oil-water ratio composite coal dust suppressant based on waste oil as described above is used to suppress dust in an area where coal dust is to be treated.
[0045] Preferably, the application of the high oil-water ratio composite coal dust suppressant based on waste engine oil comprises the following steps:
[0046] The high oil-water ratio composite coal dust suppressant based on waste oil is diluted with water in proportion and sprayed directly on the coal dust treatment area. The spraying volume is 5L / m 3 Up to 11L / m 3 ; Wherein, the coal dust to be treated area includes at least one of a coal transport vehicle, a coal mine and a coal yard.
[0047] Specifically, according to the actual situation, choose the appropriate spraying equipment, pour the biomass composite coal dust suppressant into the spraying equipment, add clean water in proportion for stirring and dilution, and after the dilution is completed, use a sprayer to spray the diluted solution on the coal dust area to be treated. When diluting the biomass composite coal dust suppressant, according to the railway industry standard of the People's Republic of China (TB / T3210.1-2020), there are Type I dust suppressants and Type II dust suppressants. Type I dust suppressants are diluted with water at a ratio of 1:50 before use and used after dilution. Type II dust suppressants are diluted with water at a ratio of 1:10 and used after dilution. The area to be treated for coal dust includes but is not limited to at least one of coal transport vehicles, coal mines, and coal yards.
[0048] See also Figure 1 and Figure 2 These are pictures of water sprayed on lignite and bituminous coal. As the water evaporates, the coal powder particles are obviously scattered everywhere. The distance between the particles is relatively large and the arrangement is relatively loose, without forming a sticky state. This can be clearly seen from the scanning electron microscope picture.
[0049] See also Figure 3 and Figure 4 The dust suppressant for this application was diluted with water at a ratio of 1:10 and then sprayed on lignite and bituminous coal. From the scanning electron microscope pictures, it can be clearly seen that the coal powders are obviously tightly combined together to form larger aggregates with a certain adhesion.
[0050] In summary, the high oil-water ratio composite coal dust suppressant based on waste oil of the present invention can make the coal powder tightly combined, can effectively prevent the coal powder particles from floating in the air, achieve the effect of dust reduction and dust suppression, and reduce the pollution caused by dust floating in the air and the harm of dust to the human body. At the same time, it solves the economic losses and environmental pollution caused by dust during the transportation and use of coal, and alleviates the harm of dust to the life and health of coal workers to a certain extent.
[0051] It is worth noting that, in the above-mentioned embodiments, the process temperature and process time involved are the temperature or time used in the experimental process. The technical personnel in this field can make adjustments within a reasonable error range based on the process temperature and process time provided by the present invention, which should be included in the protection scope of the present invention.
[0052] The technical solution and technical effects of the present invention are further illustrated below through specific experimental examples.
[0053] 1. Main Reagents
[0054] In the embodiments of the present invention, waste engine oil comes from a local 4S store in Ningxia; lignite comes from Ningxia, and bituminous coal comes from Shenmu, Yulin, Shaanxi; other reagents and solvents are commercially available and can be used without further purification.
[0055] 2. Performance test methods and standards
[0056] 2.1 Stability test of dust suppressant
[0057] To explore whether different surfactants can avoid oil-water separation and inability to emulsify in oil-water mixtures, and to determine their stability.
[0058] 2.2 Viscosity test of dust suppressant
[0059] The prepared high oil-water ratio composite coal dust suppressant is diluted with water in a certain proportion and then measured using a viscometer NDJ-8S.
[0060] 2.3 Test of the solidified layer of dust suppressant
[0061] Dilute the prepared high oil-water ratio composite coal dust suppressant according to a certain ratio, weigh 200-mesh coal powder and spread it evenly in a 6-cm culture dish with a height of 1.5 cm. Then use a spray bottle to evenly spray the diluted high oil-water ratio composite coal dust suppressant solution on the coal powder, and finally wait for the solution to penetrate completely at room temperature until constant weight.
[0062] 2.4 Wind erosion rate test of dust suppressant
[0063] Dilute the prepared dust suppressant according to a certain proportion, take 200-mesh coal powder and spread it flat in small round boxes with a diameter of 6 cm. The height of the coal powder is 1.5 cm. Use a spray bottle to evenly spray the diluted dust suppressant solution on the coal powder. Wait for the solution to penetrate completely at room temperature until constant weight, weigh the initial mass of the coal powder and the small round box before blowing, blow it for 5 minutes at a wind speed of 30 m / s, and then weigh the mass of the coal powder and the small round box after blowing.
[0064] The wind erosion rate formula is:
[0065] Where: E is wind erosion rate;
[0066] m 0 : The mass of coal powder and small round box before erosion, in grams (g);
[0067] m 1: The mass of coal powder and small round box after blowing, in grams (g);
[0068] m 2 : Mass of the small round box, in grams (g).
[0069] 2.5 Water retention test of high oil-water ratio composite coal dust suppressant
[0070] Take 2.0 g of completely constant weight coal powder, spray 4.0 g of water evenly on the coal powder using a rubber-tipped dropper, weigh the initial total mass of the culture dish, coal powder and water, and then place it at room temperature, weigh its mass after 6 h, 12 h, 24 h, 36 h, and 48 h, respectively, and calculate the water retention rate of each group of experimental samples according to the water retention rate formula.
[0071] The water loss rate formula is:
[0072]
[0073] Where: θ: water loss rate
[0074] w: total mass of the initial sample culture dish, in grams (g);
[0075] w 1 : The total mass of the sample culture dish every 24 hours, in grams (g);
[0076] All the above test results are compared with the Railway Industry Standard of the People's Republic of China (TB / T3210.1-2020) (hereinafter referred to as the Industry Standard), and the standards specified in the Industry Standard are as follows:
[0077] Viscosity: Type I>5mpa·s; Type II>50mpa·s; Type I is a dust suppressant diluted with water at a ratio of 1:50, and Type II is a dust suppressant diluted with water at a ratio of 1:10.
[0078] Thickness of cured layer: ≥10mm.
[0079] Wind erosion rate: <1%.
[0080] 3. Comparative example: exploring the dust suppression effect of waste oil
[0081] 3.1 Blank example: clear water.
[0082] 3.2 Comparative example: Take 10g of waste engine oil, add 20g of water and stir to mix. Water and oil separation occurs and it cannot be emulsified, so the coal dust suppressant cannot be synthesized.
[0083] 4. Example 1: Study on the stability of different surfactants in oil-water mixtures
[0084] 4.1 Preparation of stable oil-water mixture
[0085] Take 15g of waste oil, 30g of water, and surfactants according to Table 1. First, mix the waste oil with the first surfactant according to Table 1, stir manually with a glass rod, and obtain a first emulsion after uniformity; add the second surfactant to 30g of water according to Table 1, stir uniformly in a heat-collecting constant temperature heating magnetic stirrer at 80°C and 600r / min to obtain a second emulsion; mix the first emulsion and the second emulsion, stir at a speed of 3000r / min for 5min using a high-speed stirrer until the mixture is uniform, and obtain a uniform emulsion.
[0086] Table 1 Proportions of each group of surfactants in the oil-water mixture of Example 1
[0087]
[0088] The dust suppressant prepared above was diluted according to the ratio of 1:10 oil-water mixture emulsion, and its stability was observed and tested. The results are as follows:
[0089] Table 2 Test results of the stability of each group of surfactants in oil-water mixture in Example 1
[0090]
[0091]
[0092] Please refer to Table 1 and Table 2 for the stability results of surfactants in oil-water mixtures in Test Examples 1 to 9. Among them, Test Example 6 has the best effect, which can be stable and not stratified after 48 hours, while the test examples with other ratios have a significant gap with Test Example 6. During the test, we found that Test Examples 4 and 6 have certain advantages over other test examples: the sample of Test Example 4 stratified after 30 hours, and the sample of Test Example 6 was still stable and not stratified after 48 hours. The common point between the two is that the first surfactant is span80, and the second surfactant contains tween80. From the results, span80 and tween80 are more effective when used in combination, because span80 has a strong lipophilicity and an HLB value of 4.3, while tween80 has a strong hydrophilicity and an HLB value of 15. When span80 and tween80 are used in combination, the hydrophilic and hydrophobic balance of the system can be better adjusted, making the emulsion more widely used and more stable. Both surfactants have oleic acid groups and hydrophilic groups. The hydrophilic groups of Span80 are multiple hydroxyl groups, while the hydrophilic groups of tween80 are polyoxyethylene ether groups. They can form a mixed adsorption layer at the oil-water interface. This mixed layer is more compact and orderly than the interfacial film formed by a single surfactant, which can enhance its protective effect on emulsion droplets. In addition, both pan80 and tween80 can reduce the surface tension of the oil-water interface. Therefore, the more prominent test example 4 and the most effective test example 6 both have the surfactants span80 and tween80. As for test example 9, it also performed well because the HLB value of span20 is 8.6. Although it is not as lipophilic as span80, it is a surfactant with strong lipophilicity like span80 and can replace span80 to a certain extent. In addition, AEO-9 can help the emulsion to remain stable during dynamic exchange. When the oil droplets collide due to Brownian motion and other reasons, the AEO-9 molecules can quickly redistribute on the surface of the oil droplets, repair the damaged adsorption layer, and ensure the stability of the emulsion. Therefore, it can be confirmed that in stabilizing the oil-water mixture, the best performing surfactants are span80, tween80, and AEO-9.
[0093] Example 2: Study on the different ratios of three surfactants for achieving stability in oil-water mixtures with high oil-water ratios
[0094] 3.1 Preparation of stable oil-water mixture with high oil-water ratio
[0095] Waste oil and water were added according to Table 3, and the amounts of three surfactants, span80, tween80, and AEO-9, were added according to Table 3. First, the waste oil was mixed with span80, and stirred manually with a glass rod to obtain a first emulsion after being uniform; tween80 and AEO-9 were added to water, and stirred uniformly in a heat-collecting constant temperature heating magnetic stirrer at 80°C and 600r / min to obtain a second emulsion; the first emulsion and the second emulsion were mixed, and stirred at a speed of 3000r / min for 5min using a high-speed stirrer until they were uniformly mixed to obtain a uniform emulsion.
[0096] Table 3 Proportions of surfactants in Example 2 at different oil-water ratios
[0097] Embodiment 2 Waste oil(g) Water(g) Span 80(g) Tween80(g) AEO-9(g) Test Example 10 18 30 1.2 1.8 1.5 Test Example 11 18 30 2 3 2 Test Example 12 18 30 2.4 3.6 3 Test Example 13 18 30 2.4 4.1 3 Test Example 14 22 30 1.2 1.8 1.5 Test Example 15 22 30 2 3 2 Test Example 16 22 30 2.4 3.6 3 Test Example 17 22 30 2.4 4.1 3 Test Example 18 25 30 2 3 2 Test Example 19 25 30 2.4 3.6 3 Test Example 20 25 30 2.4 4.1 3 Test Example 21 30 30 2.4 3.6 3
[0098] 3.2 The prepared test sample was diluted according to the ratio of 1:10 oil-water mixture emulsion, and its stability was observed and tested. The results are as follows:
[0099] Table 4 Test results of the ratio stability of the three surfactants in Example 2 at different oil-water ratios
[0100] Embodiment 2 stability Test Example 10 48h still stable Test Example 11 48h still stable Test Example 12 48h still stable Test Example 13 48h still stable Test Example 14 Stratification occurs after 28 hours Test Example 15 Delamination occurs after 36 hours Test Example 16 48h still stable Test Example 17 48h still stable Test Example 18 Delamination occurs after 30 hours Test Example 19 48h still stable Test Example 20 Delamination after 40 hours Test Example 21 Delamination occurs after 36 hours
[0101] It can be seen from Table 4 that when the oil-water ratio is 18:30 (i.e. 37.5%), when the mass ratio of Tween80 and AEO-9 in Test Examples 10 to 14 is (1.5 to 4.1): (1.5 to 3), they can all meet the requirement of 48h stability without stratification. However, when the oil-water ratio is increased, the ratio of different surfactants will lead to oil-water stratification. From the test data, when the oil-water ratio is 22:30 (i.e. 42.3%), when the mass ratio of Tween80 and AEO-9 in Test Examples 16 to 17 is (3.6 to 4.1): 3, they can meet the requirement of 48h stability without stratification; when the oil-water ratio is 25:30 (i.e. 45.5%), when the mass ratio of Tween80 and AEO-9 in Test Example 19 is 3.6: 3, they can meet the requirement of 48h stability without stratification, and the other test examples all show stratification in less than 48 hours. However, when the oil-water ratio is increased to 30:30 (ie, 50%), stratification will occur and stability will decrease. In other words, Test Example 19 still maintains oil-water stability when the oil-water ratio is increased to 45.5%, which is significantly better than other data under the same oil-water ratio.
[0102] 4. Example 3: Investigating the influence of binder on dust suppressant
[0103] 4.1 Preparation of dust suppressants
[0104] Take 25g of waste oil, 30g of water, 2.4g of the first surfactant (span80), 6.6g of the second surfactant (including 3g of AEO-9 and 3.6g of tween80), and add the binder and moisturizer according to Table 5. Mix the waste oil with 2.4g of the surfactant (span80) and stir evenly to obtain emulsion 1. Add the second surfactant, binder and moisturizer into water according to Table 5, stir evenly in a heat-collecting constant temperature heating magnetic stirrer at 80°C and 600r / min to obtain a second emulsion; mix the first emulsion and the second emulsion, stir at a speed of 3000r / min for 5min using a high-speed stirrer until the mixture is evenly mixed to obtain a uniform emulsion.
[0105] 4.2 The performance test method of high oil-water ratio composite coal dust suppressant is as follows
[0106] 4.2.1 Viscosity test of high oil-water ratio composite coal dust suppressant solution
[0107] The prepared high oil-water ratio composite coal dust suppressant was diluted with water in a ratio of 1:10, and then measured using a viscometer NDJ-8S.
[0108] 4.2.2 Test of the thickness of the solidified layer of high oil-water ratio composite coal dust suppressant
[0109] Dilute the above-prepared high oil-water ratio composite coal dust suppressant with water in a ratio of 1:10, weigh 200-mesh lignite and bituminous coal, and spread them flat in a culture dish with a diameter of 6 cm, with the coal powder height of 1.5 cm. Then use a spray bottle to evenly spray the diluted biomass composite coal dust suppressant solution on the coal powder, and finally wait for the solution to penetrate completely at room temperature until constant weight.
[0110] 4.2.3 Wind erosion rate test of high oil-water ratio composite coal dust suppressant
[0111] Dilute the prepared high oil-water ratio composite coal dust suppressant in a ratio of 1:10, take 200-mesh lignite and bituminous coal, spread them flat in small round boxes with a diameter of 7 cm, and the height of the coal powder is 1.5 cm. Use a spray bottle to evenly spray the diluted dust suppressant solution on the coal powder, wait for the solution to penetrate completely at room temperature until constant weight, weigh the initial mass of the coal powder and the small round box before blowing, blow for 5 minutes at a wind speed of 30 m / s, and then weigh the mass of the coal powder and the small round box after blowing.
[0112] 4.2.4 Water retention test of high oil-water ratio composite coal dust suppressant
[0113] Take 2g of coal powder, spray 4g of diluted high oil-water ratio composite coal dust suppressant evenly on the coal powder using a rubber-tipped dropper, weigh the initial total mass of the culture dish, coal powder and diluted high oil-water ratio composite coal dust suppressant, and then place it in an oven at an average temperature of 25°C, weigh its mass after 6h, 12h, 24h, 36h, and 48h, respectively, and calculate the water retention rate of each group of experimental samples according to the water retention rate formula.
[0114] Table 5 Proportions of composite coal dust suppressants based on waste oil and high oil-water ratio in each group of Example 3
[0115]
[0116] 4.3 Performance test of composite coal dust suppressant based on waste oil with high oil-water ratio
[0117] The prepared waste oil-based high oil-water ratio composite coal dust suppressant was diluted at a ratio of 1:10 and tested according to the performance test method and standard. The results are as follows:
[0118] Table 6 Performance test results of each group of composite coal based on waste oil and high oil-water ratio in Example 3 1
[0119]
[0120]
[0121] Table 7 Performance test results of each group of composite coal based on waste oil and high oil-water ratio in Example 3
[0122]
[0123] As can be seen from Table 6, the data of the compound composed of Test Example 28 are the best. When diluted with water at a ratio of 1:10, the viscosity can reach 128.6mpa.s, and the solidified layer acting on the sample coal also reaches an average of 13mm to 14mm, and the average wind erosion rate is only 0.29%. Compared with the national railway industry standard (Type II: dust suppressant and water are diluted at a ratio of 1:10, the viscosity in the railway industry standard is >50mpa·s; wind erosion rate <1%; solidified layer thickness >10mm), the viscosity is increased by 157.2%, the solidified layer thickness is increased by 30% to 40%, and the average wind erosion rate is reduced by 71%, which is significantly better than the railway industry standard. It can also be seen from the water retention rate in Table 7 that the water retention rate of Test Example 28 from 6h to 48h is significantly better than other test examples. It shows that the dust suppressant of this application has significantly better performance indicators than the national standard on the basis of adding a large amount of waste oil, which not only reduces the production cost but also has a good use effect.
[0124] 5. Example 4: Investigating the effects of different preparation methods on the performance of dust suppressants
[0125] 5.1 Preparation of comparative dust suppressants
[0126] Take 25g of waste oil, 30g of water, 2.4g of the first surfactant (span80), 6.6g of the second surfactant (including 3g of AEO-9, 3.6g of tween80), a binder (0.18g of sodium carboxymethyl cellulose, 0.15g of xanthan gum, 1.5g of sodium polyacrylate), and 2g of a moisturizer (triethanolamine). The difference from the preparation method in Example 3 is that after the waste oil and water are mixed, other raw materials are added at one time, and then a high-speed stirrer is used to stir at a speed of 2000r / min to 3500r / min for 1min to 8min until the mixture is uniformly mixed to obtain a uniform emulsion, i.e., the desired dust suppressant for comparison.
[0127] 5.2 The prepared comparative dust suppressant was diluted at a ratio of 1:10, and the performance test method in Example 3 was used. The results were as follows:
[0128] Table 8 Test results of dust suppressants used in Example 4
[0129]
[0130] Table 9 Test results of the dust suppressant of Example 4 2
[0131]
[0132] It can be seen from Table 8 and Table 9 that even if the raw materials are the same as those in Test Example 28, different test results will still be obtained by using different preparation methods. This time, all materials were mixed and stirred at the same time, and a high-speed stirrer was used directly for stirring without using a heat-collecting constant temperature heating magnetic stirrer for heating and stirring. From the results, it can be seen that except for viscosity, the other indicators of the tested performance cannot meet the railway industry standards.
[0133] In summary, the high oil-water ratio composite coal dust suppressant based on waste engine oil disclosed in the present application includes 18 to 25 parts of waste engine oil, 1.2 to 2.4 parts of the first surfactant, 3.3 to 7.1 parts of the second surfactant, 30 parts of water, 0.96 to 1.83 parts of the binder, and 1.2 to 3 parts of the water retaining agent. The first surfactant is span80, the second surfactant is a mixture of AEO-9 and tween80, and the binder is a mixture of sodium polyacrylate, xanthan gum, and sodium carboxymethyl cellulose. The preparation steps are as follows: first, mix the waste engine oil with a first surfactant and stir them evenly to obtain a first emulsion; then, mix the water with the second surfactant, a binder, and a water retaining agent at 60°C to 85°C and stir them evenly to obtain a first emulsion; then, mix the first emulsion and the first emulsion, stir them at a speed of 2000r / min to 3500r / min for 1min to 8min, until they are evenly mixed, to obtain an emulsion with a pH of 7 to 9, that is, a high oil-water ratio composite coal dust suppressant based on waste engine oil.
[0134] The dust suppressant of this scheme adds a large amount of waste engine oil on the basis of ensuring a good dust suppression effect, and overcomes the problem that when the oil phase ratio is too high, phase inversion is easy to occur, turning into an oil-in-water emulsion, making it impossible to dilute and use as a dust suppressant for spraying. In addition, a large amount of waste engine oil is used in the preparation process, combined with the advantages of low cost and high combustion calorific value of waste engine oil. Not only can it ensure a good dust suppression effect, but it will not affect the calorific value of coal after spraying. It can also significantly reduce the production cost of high oil-water ratio composite coal dust suppressants and reduce the pollution caused to the environment by direct discharge of waste engine oil.
[0135] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.
Claims
1. A method for preparing a high oil-water ratio composite coal dust suppressant based on waste engine oil, characterized in that: The following steps are involved: S10. Prepare the materials by weighing the following parts by weight: 18 to 25 parts of waste oil, 1.2 to 2.4 parts of a first surfactant, 3.3 to 7.1 parts of a second surfactant, 30 parts of water, 0.96 to 1.83 parts of a binder, and 1.2 to 3 parts of a water retaining agent; S20. The waste oil is mixed with the first surfactant and stirred to obtain a first emulsion; S30. The water and the second surfactant, binder, and water retaining agent are mixed and stirred at 60°C to 85°C to obtain a second emulsion; S40. Mix the first emulsion and the second emulsion, and stir them at a rotation speed of 2000 r / min to 3500 r / min for 1 min to 8 min until they are evenly mixed to obtain an emulsion with a pH of 7 to 9, i.e., a high oil-water ratio composite coal dust suppressant based on waste engine oil.
2. The preparation method according to claim 1, characterized in that: The first surfactant includes any one of span60, fatty acid monoglyceride, span85, sorbitan sesquioleate, span65, polyoxyethylene monostearate, span20, monostearate glyceryl, span80, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, lauric acid, tween80, AEO-9, AEO-7, and tetraethylene glycol monolaurate.
3. The preparation method according to claim 2, characterized in that: When the first surfactant is Span65, the second surfactant is a mixture of AEO-7 and AEO-9; when the first surfactant is Span80 or Span20, the second surfactant is a mixture of any two of AEO-7, Tween80 and AEO-9.
4. The preparation method according to claim 3, characterized in that: The second surfactant is a mixture of Tween 80 and AEO-9, and the mass ratio of Tween 80 to AEO-9 is (1.5 to 4.1): (1.5 to 3).
5. The preparation method according to claim 1, characterized in that: The binder includes any three of sodium polyacrylate, guar gum, xanthan gum, galactomannan, sodium carboxymethyl cellulose, sodium alginate, gum arabic, carrageenan, arabinose, donkey-hide gelatin, and pectin.
6. The preparation method according to claim 5, characterized in that: The binder includes sodium carboxymethyl cellulose, xanthan gum and sodium polyacrylate, and the mass ratio of the sodium carboxymethyl cellulose, xanthan gum and sodium polyacrylate is (0.08 to 0.18):(0.08 to 0.15):(0.8 to 1.5).
7. The preparation method according to claim 1, characterized in that: The water retaining agent includes any one of alkyl glycoside, hydroxypropyl methylcellulose, polyethylene glycol, glycerol, triethanolamine, hyaluronic acid, carboxymethyl chitosan, sodium carboxymethyl cellulose, cetyl trimethyl ammonium chloride and sodium lignin sulfonate.
8. A high oil-water ratio composite coal dust suppressant based on waste engine oil, prepared by the preparation method of the high oil-water ratio composite coal dust suppressant based on waste engine oil according to any one of claims 1 to 7.
9. Use of the high oil-water ratio composite coal dust suppressant based on waste engine oil as claimed in claim 8 for dust suppression in an area where coal dust is to be treated.
10. The use according to claim 9, characterized in that: The following steps are involved: The high oil-water ratio composite coal dust suppressant based on waste oil is diluted with water in proportion and sprayed directly on the coal dust treatment area. The spraying volume is 5L / m 3 Up to 11L / m 3 ; Wherein, the coal dust to be treated area includes at least one of a coal transport vehicle, a coal mine and a coal yard.