Preparation method of chlorine-free long-acting low-corrosion coal anti-freezing solution for railway transportation

Abstract

The invention discloses a preparation method of a chlorine-free long-acting low-corrosion coal anti-freezing solution for railway transportation, and belongs to the technical field of coal anti-freezing solutions. The preparation method comprises the following steps: (1) putting quantitative clean water at normal temperature into a container, and slowly adding ethylene glycol under a mechanical stirring condition to obtain a mixed solution (1); (2) mixing the mixed solution (1) with quantitative sodium formate to obtain a mixed solution (2); (3) mixing the mixed solution (2) with quantitative urea to obtain a mixed solution (3); and (4) mixing the mixed solution (3) with a thickening agent, and fully stirring to obtain a finished product of the coal anti-freezing solution. The prepared anti-freezing solution has the following advantages that the raw materials are cheap and easy to obtain, and preparation can be completed in a normal-temperature state; the corrosion to metal is small, and high-toxicity and environment-harmful substances are not contained; the anti-freezing agent is stable in property, moderate in viscosity and lasting in anti-freezing effect, and does not need to be supplemented during transportation and storage; the freezing point can reach-43 to-55 DEG C, and the problems of freezing in a coal transportation process in winter and corrosion of a traditional anti-freezing solution to a railway carriage wall can be effectively solved.

Description

Technical Field

[0001] The present invention relates to a preparation method of a chlorine-free long-acting low-corrosive coal antifreeze for railway transportation, which is mainly used for preventing freezing during the railway transportation of coal and belongs to the technical field of coal antifreeze. Technical Background

[0002] As a fossil resource, coal plays an irreplaceable important role in the energy and industrial fields of our country. However, the overall distribution of coal resources in our country is unbalanced, with more in the west and less in the east, and more in the south and less in the north. The coal resources in the northwest account for 80% of the total national amount, while the coal-consuming areas are mainly concentrated in the more developed eastern regions. The coal bases are far from the consumption markets, and large-scale transportation requires the use of railways and other means.

[0003] After coal is washed and selected, it will carry some moisture. In winter, the temperature in the northwest region is relatively low. During transportation, freezing will occur between coal particles and between coal and the carriage wall, resulting in the following impacts: 1. Reducing the normal coal loading and unloading efficiency, bringing unnecessary economic and time losses; 2. Part of the coal adheres to the carriage wall, causing loss of the total cargo volume; 3. The remaining coal may change the center of gravity of the carriage, leading to potential safety hazards such as deviation of the carriage during driving.

[0004] Regarding the problem of coal freezing in the carriage during transportation, the current methods include physical deicing and spraying chemical antifreeze agents. Among them, the physical deicing methods such as electric heating, vibration, blasting, and adding a paraffin coating to the carriage wall have the following disadvantages: high cost, high labor intensity, and may also cause coal body pollution. Therefore, at present, most domestic coal enterprises use chemical coal antifreeze agents sprayed before and during loading to solve the problem of frozen coal carriages in winter.

[0005] Coal antifreeze is inexpensive and easy to use. It is suitable for the transportation of coal in train wagons in winter and high-cold regions. Usually, a product with a freezing point about 10°C lower than the lowest temperature along the operation route is selected. The antifreeze can keep the water in the coal in a state of high hydrogen bond interaction, preventing the formation of ice nuclei. At the same time, the antifreeze can change the crystal shape of ice, promoting the formation of a polycrystalline structure, destroying the lattice between ice crystals, and preventing the formation of a frozen mass. Coal antifreeze can be divided into two categories according to its composition: chlorine-free and chlorine-containing. The advantages of chlorine-free antifreeze are lower corrosion and less environmental pollution. However, its disadvantages are that the current common chlorine-free antifreeze has poor anticoagulant effect, generally only reaching -20 to -30°C, and its price is 1.5 - 2 times that of chlorine-containing antifreeze, making it unsuitable for general large-scale railway transportation. The advantages of chlorine-containing antifreeze are low cost and good anticoagulant effect. However, its disadvantages are that due to the small volume and high activity of chloride ions, it is easy to cause corrosion to metal equipment, and the inorganic salt solution has a low viscosity and is easy to fall off from the carriage and the surface of the coal, resulting in the failure of the antifreeze. Currently, chlorine-containing antifreeze mainly consists of inorganic chlorides, nitrates, benzotriazole, and thickeners. Among them, nitrates react with volatile organic compounds to generate ozone and fine particulate matter (SOA), affecting air quality and having the risk of explosion and fire. The chlorine element in the antifreeze is easy to cause rust and corrosion to coal-burning equipment, transportation equipment, and spraying equipment. At the same time, acidic gases are generated after the chlorine-containing antifreeze burns, polluting the environment.

[0006] Therefore, providing a chlorine-free long-acting low-corrosion coal antifreeze for railway transportation with good anticoagulant effect and low cost, having good anti-freezing effect, low cost, less environmental pollution, moderate viscosity, low corrosion to equipment, being able to effectively lower the freezing point of the solution, further reducing the corrosion of the depressant components to steel, aluminum, slowing down the corrosion of the antifreeze to metals, and effectively preventing the antifreeze from falling off and failing has become an urgent technical problem to be solved in this technical field. Summary of the Invention

[0007] One of the purposes of the present invention is to provide a chlorine-free coal antifreeze for railway transportation with good anti-freezing effect, low cost, less environmental pollution, moderate viscosity, low corrosion to equipment, being able to effectively lower the freezing point of the solution, further reducing the corrosion of the depressant components to steel, aluminum, slowing down the corrosion of the antifreeze to metals, and effectively preventing the antifreeze from falling off and failing in view of the problems of poor anticoagulant effect and high cost of chlorine-free coal antifreeze.

[0008] The above object of the present invention is achieved by the following technical solutions:

[0009] A chlorine-free long-acting low-corrosion coal antifreeze for railway transportation, the raw materials used and the mass percentages of each component are as follows:

[0010]

[0011] The remainder is water.

[0012] Preferably, the thickener is one or a mixture of two or more of hydroxyethyl cellulose, sodium carboxymethyl cellulose or polyacrylamide in any proportion.

[0013] Preferably, the proportion of the chlorine-free long-acting low-corrosive coal antifreeze for railway transportation is as follows:

[0014]

[0015] The remainder is water.

[0016] Preferably, the thickener is one or a mixture of two or more of hydroxyethyl cellulose, sodium carboxymethyl cellulose or polyacrylamide in any proportion.

[0017] Another object of the present invention is to provide a preparation method of the above-mentioned chlorine-free long-acting low-corrosive coal antifreeze for railway transportation.

[0018] The above object of the present invention is achieved by the following technical solutions:

[0019] A preparation method of a chlorine-free long-acting low-corrosive coal antifreeze for railway transportation, the steps are as follows:

[0020] (1) Take a certain amount of clear water at normal temperature, place it in a container, and slowly add ethylene glycol under mechanical stirring to obtain a mixed solution (1);

[0021] (2) Mix the mixed solution (1) obtained in step (1) with sodium formate and stir well to obtain a mixed solution (2);

[0022] (3) Mix the mixed solution (2) obtained in step (2) with a certain amount of urea and stir well to obtain a mixed solution (3);

[0023] (4) Mix the mixed solution (3) obtained in step (3) with a thickener and stir well until completely dissolved to obtain the finished coal antifreeze.

[0024] Preferably, in step (4), the thickener is one or a mixture of two or more of sodium carboxymethyl cellulose, sodium hydroxyethyl cellulose or polyacrylamide.

[0025] Another object of the present invention is to provide the application of the above-mentioned chlorine-free long-acting low-corrosive coal antifreeze for railway transportation.

[0026] The above object of the present invention is achieved by the following technical solutions:

[0027] The application of the chlorine-free long-acting low-corrosive coal antifreeze for railway transportation in railway transportation, the steps are as follows:

[0028] (1) Spray coal antifreeze on the surface of coal transportation vehicles. The spraying amount per unit surface area of coal shall be not less than 2.2 L / m 2 ; When spraying the solution on the freight cars with the coal loaded exceeding the height of the end side wall of the freight car, the spraying amount per unit surface area of coal shall be not less than 3.5 L / m 2 ;

[0029] (2) When the temperature is below 0 °C, expand the coal antifreeze to spray on the inner wall and bottom plate of the empty coal-loading freight cars, spraying 2 - 2.5 liters per square meter to form an anti-freezing layer between coal seams;

[0030] (2) When the temperature is below 0 °C, spray the antifreeze layer by layer between coal seams during coal filling, spraying 2 - 2.5 liters per square meter to form an anti-freezing layer between coal seams.

[0031] Beneficial effects:

[0032] The antifreeze prepared by the present invention has the following advantages compared with traditional antifreezes: the raw materials are cheap and easily available, and the preparation can be completed at normal temperature; it has little corrosion to metals and does not contain highly toxic and environmentally harmful substances; it has stable properties, moderate viscosity, and long-lasting anti-freezing effect, and no additional supplement is required during transportation and storage; the freezing point can reach -43 ~ -55 °C. According to specific situations, after spraying on the surface of coal and the carriage wall, it can effectively solve the freezing problem during winter coal transportation and the corrosion of the railway carriage wall by traditional antifreezes.

[0033] The present invention will be described in detail below through specific embodiments. It should be understood that the described embodiments only relate to the preferred implementation schemes of the present invention, and various changes and improvements in the components and their contents are possible without departing from the spirit and scope of the present invention. Specific embodiments

[0034] Unless otherwise specified, the raw materials used in the embodiments of the present invention are all raw materials that can be purchased in the market, the equipment used is conventional equipment in the technical field, the methods used are conventional methods in the technical field, and the ratios are all weight ratios.

[0035] Example 1

[0036] Take 43.3 g of clear water, and slowly add 27 g of ethylene glycol under mechanical stirring. After complete dissolution, add 24 g of sodium formate. After complete dissolution, add 5 g of urea, stir and dissolve thoroughly, and then add 0.7 g of hydroxyethyl cellulose and mix and dissolve completely to obtain the finished antifreeze 1.

[0037] Example 2

[0038] Take 49.5 g of clear water. Under mechanical stirring conditions, slowly add 24 g of ethylene glycol. After complete dissolution, add 21 g of sodium formate. After complete dissolution, add 5 g of urea. Stir well until dissolved. Then add 0.5 g of sodium carboxymethyl cellulose and mix thoroughly until dissolved to obtain finished antifreeze 2.

[0039] Example 3

[0040] Take 49.9 g of clear water. Under mechanical stirring conditions, slowly add 22 g of ethylene glycol. After complete dissolution, add 24 g of sodium formate. After complete dissolution, add 4 g of urea. Stir well until dissolved. Then add 0.1 g of polyacrylamide and mix thoroughly until dissolved to obtain finished antifreeze 3.

[0041] Example 4

[0042] Take 50.5 g of clear water. Under mechanical stirring conditions, slowly add 20 g of ethylene glycol. After complete dissolution, add 24 g of sodium formate. After complete dissolution, add 5 g of urea. Stir well until dissolved. Then add 0.1 g of polyacrylamide and 0.4 g of sodium carboxymethyl cellulose and mix thoroughly until dissolved to obtain finished antifreeze 4.

[0043] For the antifreeze prepared according to Examples 1 - 4, its performance indicators such as freezing point, corrosiveness, density, viscosity, etc. fully comply with the "Technical Conditions for Antifreeze Used in the Transportation of Bulk Granular Goods (TB / T 3208 - 2008)". Among them, the density is measured according to the method specified in GB / T13354, the test temperature is (20 ± 1) °C, and the arithmetic mean of 3 tested samples is taken as the test result (see Table 1 below); the viscosity is measured according to the method specified in GB / T 10247, the test temperature is (25 ± 1) °C, and the arithmetic mean of 3 tested samples is taken as the test result (see Table 1 below); the pH is measured according to the method specified in GB / T 14518, and the arithmetic mean of 3 tested samples is taken as the test result (see Table 1 below); the metal corrosiveness is measured according to the method specified in JB / T7901. The sample is placed in a glass sealed container filled with the antifreeze solution and soaked for at least 168 h under the condition of an ambient temperature of (20 ± 5) °C. The arithmetic mean of 3 tested samples for each material is taken as the test result (see Table 1 below); the freezing point is tested according to SH / T 0065, and the arithmetic mean of 2 tested samples is taken as the test result (see Table 1 below). When used on coal - transporting trains in the north in winter, after transportation to the port, the coal has no frozen bottom, no sticking, and is easy to unload.

[0044] Through monomer material screening experiments, orthogonal experiments, dilution experiments, and property and performance index determination experiments, the results of the antifreeze performance of the coal antifreeze in Examples 1 to 4 are shown in Table 1 below:

[0045] Table 1

[0046]

[0047] The usage methods of the products in the above-mentioned Embodiment 1 - Embodiment 4 are as follows:

[0048] (1) Spray antifreeze on the surface of coal transportation vehicles, and the spraying amount per unit surface area of coal shall be not less than 2.2 L / m 2 ; when spraying the dust suppressant solution on the freight cars with coal loaded exceeding the height of the end side wall of the freight car, the spraying amount per unit surface area of coal shall be not less than 3.5 L / m 2 ;

[0049] (2) When the temperature is below 0 °C, expand the antifreeze to spray on the inner wall and bottom plate of the empty coal-loading cars, spraying 2 - 2.5 liters per square meter to form an antifreeze layer between coal seams; or

[0050] (2) When the temperature is below 0 °C, during coal filling, spray the antifreeze layer by layer between coal seams, spraying 2 - 2.5 liters per square meter to form an antifreeze layer between coal seams.

[0051] The chlorine-free long-acting low-corrosive coal antifreeze for railway transportation of the present invention, wherein ethylene glycol and sodium formate are anticoagulants; urea is used as a corrosion inhibitor; sodium carboxymethylcellulose, hydroxyethyl cellulose and polyacrylamide are used as thickeners. The chlorine-free long-acting low-corrosive coal antifreeze for railway transportation of the present invention has cheap and easily available raw materials, a simple production process, high stability, little environmental pollution, good corrosion resistance, and can effectively solve the freezing problem during winter coal transportation and the corrosion of the railway carriage wall by traditional antifreeze.

[0052] In the present invention, ethylene glycol and sodium formate are anticoagulants, which can effectively reduce the freezing point of the solution; urea is used as a corrosion inhibitor, which can effectively reduce the corrosion of steel, aluminum by the anticoagulant by forming a protective film on the metal surface; sodium carboxymethylcellulose, hydroxyethyl cellulose or polyacrylamide are used as thickeners, making the antifreeze can stably adhere to the carriage wall or the coal surface, preventing the antifreeze from falling off and becoming ineffective.

[0053] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A preparation method of a chlorine-free long-acting low-corrosive coal antifreeze for railway transportation, the raw materials used and the mass percentages of each component are as follows: The balance is water; The steps are as follows: (1) Take a certain amount of clear water at room temperature and place it in a container. Under mechanical stirring conditions, slowly add ethylene glycol to obtain a mixed solution (1); (2) Mix the mixed solution (1) obtained in step (1) with a certain amount of sodium formate and stir well to obtain a mixed solution (2); (3) Mix the mixed solution (2) obtained in step (2) with a certain amount of urea and stir well to obtain a mixed solution (3); (4) Mix the mixed solution (3) obtained in step (3) with a thickener and stir well until completely dissolved to obtain the finished coal antifreeze product.

2. The preparation method of the chlorine-free long-acting low-corrosive coal antifreeze for railway transportation according to claim 1, wherein: In step (4), the thickener is one or a mixture of two or more of sodium carboxymethyl cellulose, sodium hydroxyethyl cellulose or polyacrylamide in any proportion.

3. The preparation method of the chlorine-free long-acting low-corrosive coal antifreeze for railway transportation according to claim 1, wherein: The proportion of the chlorine-free long-acting low-corrosive coal antifreeze for railway transportation is as follows: The balance is water.

4. The preparation method of the chlorine-free long-acting low-corrosive coal antifreeze for railway transportation according to claim 3, wherein: The thickener is one or a mixture of two or more of hydroxyethyl cellulose, sodium carboxymethyl cellulose or polyacrylamide in any proportion.

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