Method for inhibiting argillization in coal washing process

Abstract

The invention discloses a method for inhibiting argillization in a coal washing process, and relates to the technical field of coal processing.The argillization inhibitor comprises filler and auxiliaries, the filler comprises sodium oleate and sodium hexametaphosphate, and the auxiliaries comprise a stabilizer, an antioxidant, a surfactant and an emulsifier; a layer of argillization inhibitor is sprayed on the surface of the coal in advance, so that the surface of the coal is covered with the argillization inhibitor, oil acid radical ions in the argillization inhibitor are adsorbed on the surface of the coal, the content of hydroxyl and hydrocarbon groups on the surface of the coal is increased, the hydrophobicity of the coal particles is improved, and therefore the coal particles are not prone to being dissolved; sodium hexametaphosphate in the argillization inhibitor can enhance the barrier effect among coal particles, so that the coal particles are in a dispersed state, the hydrophilicity of high-ash components in the coal is improved, the high-ash substances in the coal are inhibited from floating out along with clean coal, and the coal slime water treatment is facilitated. The purpose of reducing the ash content of the flotation clean coal is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal processing, in particular to a method for inhibiting mudding in a coal washing process. Background Art

[0002] As we all know, coal occupies an important position in my country's energy structure. Under the new normal, the moderate and high-quality development of my country's economy and society has put forward higher requirements for the clean production and utilization of coal. Coal washing is the main means of clean utilization of coal. At present, the washing ratio in my country has exceeded 60%. Coal washing generally refers to the process of removing gangue or other impurities from coal. Coal washing is generally carried out by utilizing the different physical properties of coal and gangue to separate coal and gangue (impurities) in media of different densities or characteristics. During the coal washing process, the coal is soaked in water, and the particles collide with each other and crushed, producing a large amount of coal slime water. If it cannot be properly handled and recycled, it will cause serious environmental pollution and waste of water resources. Coal slime water affects the entire process of coal washing, and it is produced in large quantities, high concentrations, and complex properties. Coal slime water treatment has become the most difficult process to manage in the coal preparation process with a wide range of involvement, large investment, and

[0003] At present, the main coal washing process in domestic industry is heavy medium or jigging-flotation process. With the mechanized mining of coal resources, the secondary coal slime is increasing and becoming more and more difficult to select, and sometimes it is even difficult to obtain qualified flotation clean coal. For this reason, we propose a method for inhibiting mud formation in coal washing process, which can reduce the amount of secondary coal slime, reduce the ash content of flotation clean coal, and improve the quality of clean coal. Summary of the invention

[0004] The purpose of the present invention is to provide a method for inhibiting mud formation during coal washing, so as to solve the problem that the existing coal washing process proposed in the above background technology cannot effectively inhibit the mud formation of coal, resulting in excessive amount of secondary coal mud, which affects the quality of flotation products. To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A method for inhibiting mudding in a coal washing process, the method comprises the following steps:

[0006] S1. First, prepare the mud inhibitor in a mixing tank.

[0007] S2. Then, before coal flotation, the mudification inhibitor is evenly sprayed on the coal surface through a spraying system to form a mudification inhibition layer on the coal surface;

[0008] S3. Finally, the coal is transported to the eddy current flotation equipment for flotation.

[0009] As a further solution of the present invention: the mud inhibitor includes fillers and additives, the fillers include sodium oleate and sodium hexametaphosphate, and the additives include stabilizers, antioxidants, surfactants and emulsifiers.

[0010] As a further solution of the present invention: the mass ratio of the sodium hexametaphosphate to the sodium oleate is 1:15-45.

[0011] As a further solution of the present invention: the stabilizer, antioxidant, surfactant and emulsifier are added in a ratio of 3:1:3:1.

[0012] As a further solution of the present invention: the vortex flotation equipment includes a flotation box and a turbine device, and the turbine device is installed in the middle of the flotation box.

[0013] As a further solution of the present invention: the spray system includes a suction pump, a spray pipe and a nozzle, the liquid inlet port of the suction pump is connected to the discharge port of the mixing tank, the liquid outlet port of the suction pump is connected to the spray pipe, and a plurality of nozzles are installed at the bottom of the spray pipe.

[0014] As a further solution of the present invention: the mixing tank includes a heating tank and a stirrer, and the stirrer is installed on the heating tank.

[0015] As a further solution of the present invention: before the mudding inhibitor is sprayed on the coal surface in step S2, it needs to be quickly rinsed with clean water.

[0016] As a further solution of the present invention: the preparation method of the mud inhibitor comprises the following steps:

[0017] S1. Add the sodium hexametaphosphate to be dissolved into a mixing tank filled with warm water, stir evenly in the warm water, heat the water to 70°C-80°C and continue stirring until the sodium hexametaphosphate is completely dissolved, add sodium oleate, and then stir for 3-5 hours, maintaining the temperature at 30-50°C during stirring.

[0018] S2. Add stabilizer, antioxidant, surfactant and emulsifier into the mixing tank in sequence, and continue heating and stirring for 2 hours to mix them completely.

[0019] S3. After the mixed liquid is cooled to room temperature, it is evenly sprayed on the surface of the coal through a spray system installed above the coal conveying mechanism.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention pre-sprays a layer of mudification inhibitor on the surface of coal so that the surface of coal is covered with the mudification inhibitor. The oleate ions in the mudification inhibitor are adsorbed on the surface of coal, resulting in an increase in the content of hydroxyl and hydrocarbon groups on the surface of coal, thereby improving the hydrophobicity of coal particles, making the coal particles less likely to be dissolved, thereby achieving mudification inhibition and providing convenience for subsequent coal slime water treatment. In addition, the sodium hexametaphosphate in the mudification inhibitor will enhance the barrier effect between coal particles, making the coal particles in a dispersed state, and improving the hydrophilicity of high-ash components in coal, thereby inhibiting the floating of high-ash substances in coal with clean coal, thereby achieving the purpose of reducing the ash content of flotation clean coal.

[0022] 2. The present invention provides eddy current flotation equipment, and the coal flows with the water flow in the eddy current flotation equipment, which can reduce the probability of coal in water colliding with each other, avoid crushing and producing secondary coal slime due to collision, and thereby reduce the degree of mudification, thereby achieving the effect of inhibiting mudification.

[0023] 3. The present invention separates the washing from the flotation by pre-fast surface washing of the coal and then flotation, which can reduce impurities on the surface of the coal and allow the mud inhibitor sprayed out later to directly contact the coal surface, resulting in a better coal mud inhibition effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the overall workflow diagram of the present invention.

[0025] Figure 2 The present invention is a production flow chart of the mud inhibitor.

[0026] Figure 3 It is a schematic diagram of the device structure of the present invention.

[0027] Figure 4 This is a comparison chart of the mudification inhibition of Examples 1-3 of the present invention.

[0028] 1. Flotation box; 2. Turbine device; 3. Heating tank; 4. Agitator; 5. Suction pump; 6. Spray pipe; 7. Nozzle. DETAILED DESCRIPTION

[0029] 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.

[0030] A method for inhibiting mudification in a coal washing process comprises a mudification inhibitor and an auxiliary agent. The mudification inhibitor comprises a filler and an auxiliary agent. The filler comprises sodium oleate and sodium hexametaphosphate. Oleate ions in sodium oleate are adsorbed on the surface of coal, resulting in an increase in the content of hydroxyl and hydrocarbon groups on the surface of coal, thereby improving the hydrophobicity of coal particles, making the coal particles difficult to dissolve, thereby achieving mudification inhibition, providing convenience for subsequent coal slime water treatment, and achieving a better mudification inhibition effect. Sodium hexametaphosphate can enhance the barrier effect between coal particles, making the coal particles in a dispersed state, improving the hydrophilicity of high-ash components in coal, thereby inhibiting the high-ash substances in coal from floating out with clean coal, and achieving the purpose of reducing the ash content of flotation clean coal. The auxiliary agent comprises a stabilizer, an antioxidant, a surfactant and an emulsifier. The stabilizer, antioxidant, surfactant and emulsifier are added in a ratio of 3:1:3:1, and the auxiliary agent accounts for 0.5%-0.8% of the total formula mass.

[0031] See also Figure 3 The vortex flotation equipment includes a flotation box 1 and a turbine device 2, the turbine device 2 is installed in the middle of the flotation box 1, the spray system includes a suction pump 5, a spray pipe 6 and a nozzle 7, the liquid inlet port of the suction pump 5 is connected to the discharge port of the mixing tank, the liquid outlet port of the suction pump 5 is connected to the spray pipe 6, and a plurality of nozzles 7 are installed at the bottom of the spray pipe 6. The mixing tank includes a heating tank 3 and a stirrer 4, and the stirrer 4 is installed on the heating tank 3.

[0032] Example 1

[0033] See also Figure 1-2 , first, prepare a mud inhibitor in a mixing tank; when preparing the mud inhibitor, add the sodium hexametaphosphate to be dissolved into a mixing tank filled with warm water, stir evenly in the warm water, heat the water to 70°C-80°C and continue stirring until the sodium hexametaphosphate is completely dissolved, add sodium oleate thereto, the mass ratio of sodium hexametaphosphate to sodium oleate is 1:15, and then stir for 3-5 hours by a stirrer 4, keep the temperature at 30-50°C during the stirring process, then add stabilizer, antioxidant, surfactant and emulsifier to the mixing tank in turn, continue heating and stirring for 2 hours to make it completely mixed, and finally cool the mixed solution to room temperature;

[0034] Then, before coal flotation, the mud inhibitor is evenly sprayed on the coal surface through a spray system installed above the coal conveying mechanism to form a mud inhibition layer on the coal surface. During spraying, the suction pump 5 is started to extract the mud inhibitor in the mixing tank and spray it downward to the coal surface through each nozzle 7 on the spray pipe 6, and flows downward along the coal surface to wrap the coal;

[0035] Finally, the coal is transported to the vortex flotation equipment for flotation. During flotation, coal with a density less than that of water will float on the water surface, and gangue with a density greater than that of water will settle to the bottom of the water. The turbine device 2 is started to make the liquid flow in the flotation box 1 rotate. In this state, the coal particles can rotate with the liquid flow at a more uniform speed and be quickly discharged from the upper coal outlet of the flotation box 1. The gangue will also rotate with the liquid flow and be discharged from the bottom outlet of the flotation box 1. In this way, the time for the coal to be immersed in water can be reduced, and the time for the coal slime water to be generated can be shortened.

[0036] Example 2

[0037] See also Figure 1-2 , first prepare a mud inhibitor in a mixing tank; when preparing the mud inhibitor, add the sodium hexametaphosphate to be dissolved into a mixing tank filled with warm water, stir evenly in the warm water, heat the water to 70°C-80°C and continue stirring until the sodium hexametaphosphate is completely dissolved, add sodium oleate thereto, the mass ratio of sodium hexametaphosphate to sodium oleate is 1:30, and then stir for 3-5 hours by a stirrer 4, keep the temperature at 30-50°C during the stirring process, then add stabilizer, antioxidant, surfactant and emulsifier to the mixing tank in turn, continue heating and stirring for 2 hours to make it completely mixed, and finally cool the mixed solution to room temperature;

[0038] Then, before coal flotation, the mud inhibitor is evenly sprayed on the coal surface through a spray system installed above the coal conveying mechanism to form a mud inhibition layer on the coal surface. During spraying, the suction pump 5 is started to extract the mud inhibitor in the mixing tank and spray it downward to the coal surface through each nozzle 7 on the spray pipe 6, and flows downward along the coal surface to wrap the coal;

[0039] Finally, the coal is transported to the vortex flotation equipment for flotation. During flotation, coal with a density less than that of water will float on the water surface, and gangue with a density greater than that of water will settle to the bottom of the water. The turbine device 2 is started to make the liquid flow in the flotation box 1 rotate. In this state, the coal particles can rotate with the liquid flow at a more uniform speed and be quickly discharged from the upper coal outlet of the flotation box 1. The gangue will also rotate with the liquid flow and be discharged from the bottom outlet of the flotation box 1. In this way, the time for the coal to be immersed in water can be reduced, and the time for the coal slime water to be generated can be shortened.

[0040] Example 3

[0041] See also Figure 1-2, first, prepare a mud inhibitor in a mixing tank; when preparing the mud inhibitor, add the sodium hexametaphosphate to be dissolved into a mixing tank filled with warm water, stir evenly in the warm water, heat the water to 70°C-80°C and continue stirring until the sodium hexametaphosphate is completely dissolved, add sodium oleate thereto, the mass ratio of sodium hexametaphosphate to sodium oleate is 1:45, and then stir for 3-5 hours by a stirrer 4, keep the temperature at 30-50°C during the stirring process, then add a stabilizer, an antioxidant, a surfactant and an emulsifier to the mixing tank in sequence, continue heating and stirring for 2 hours to make it completely mixed, and finally cool the mixed solution to room temperature;

[0042] Then, before coal flotation, the mud inhibitor is evenly sprayed on the coal surface through a spray system installed above the coal conveying mechanism to form a mud inhibition layer on the coal surface. During spraying, the suction pump 5 is started to extract the mud inhibitor in the mixing tank and spray it downward to the coal surface through each nozzle 7 on the spray pipe 6, and flows downward along the coal surface to wrap the coal;

[0043] Finally, the coal is transported to the vortex flotation equipment for flotation. During flotation, coal with a density less than that of water will float on the water surface, and gangue with a density greater than that of water will settle to the bottom of the water. The turbine device 2 is started to make the liquid flow in the flotation box 1 rotate. In this state, the coal particles can rotate with the liquid flow at a more uniform speed and be quickly discharged from the upper coal outlet of the flotation box 1. The gangue will also rotate with the liquid flow and be discharged from the bottom outlet of the flotation box 1. In this way, the time for the coal to be immersed in water can be reduced, and the time for the coal slime water to be generated can be shortened.

[0044] Sodium oleate is difficult to be adsorbed on the surface of gangue and has little effect on the floatability of gangue.

[0045] After comparing the above examples 1-3, we found that the coal sliming inhibition effect of example 2 was the best, so example 2 is the best example of the present invention. The comparison chart of coal sliming inhibition of examples 1-3 is as follows: Figure 4 shown.

[0046] After coal washing by the method of Example 2, the production index of the coal preparation plant was significantly improved, the clean coal yield was increased by 5.29%, the coal loss was reduced from 13% to about 7.3%, and the economic benefits of the coal preparation plant were increased.

[0047] It should be noted that before spraying the coal with mud inhibitor, the coal needs to be sprayed and washed to keep the surface of the coal clean to prevent the coal from being unable to be washed clean due to the presence of mud inhibitor during subsequent washing.

[0048] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for inhibiting mudding in a coal washing process, characterized in that: The method steps are as follows: S1. First, prepare the mud inhibitor in a mixing tank. S2. Then, before coal flotation, the mudification inhibitor is evenly sprayed on the coal surface through a spraying system to form a mudification inhibition layer on the coal surface; S3. Finally, the coal is transported to the eddy current flotation equipment for flotation.

2. The method for suppressing mud formation in a coal washing process according to claim 1, characterized in that: The mud inhibitor comprises fillers and auxiliary agents, wherein the fillers comprise sodium oleate and sodium hexametaphosphate, and the auxiliary agents comprise stabilizers, antioxidants, surfactants and emulsifiers.

3. The method for suppressing mud formation in a coal washing process according to claim 2, characterized in that: The mass ratio of the sodium hexametaphosphate to sodium oleate is 1:15-45.

4. The method for suppressing mud formation in a coal washing process according to claim 2, characterized in that: The stabilizer, antioxidant, surfactant and emulsifier are added in a ratio of 3:1:3:

1.

5. The method for suppressing mud formation in a coal washing process according to claim 1, characterized in that: The vortex flotation equipment comprises a flotation box (1) and a turbine device (2), wherein the turbine device (2) is installed in the middle of the flotation box (1).

6. The method for suppressing mud formation in a coal washing process according to claim 1, characterized in that: The spray system comprises a suction pump (5), a spray pipe (6) and a nozzle (7); the liquid inlet port of the suction pump (5) is connected to the material outlet port of the mixing tank; the liquid outlet port of the suction pump (5) is connected to the spray pipe (6); and a plurality of nozzles (7) are installed at the bottom of the spray pipe (6).

7. The method for suppressing mud formation in a coal washing process according to claim 1, characterized in that: The mixing tank comprises a heating tank (3) and a stirrer (4), wherein the stirrer (4) is installed on the heating tank (3).

8. The method for suppressing mud formation in a coal washing process according to claim 1, characterized in that: In step S2, the mudding inhibitor needs to be quickly rinsed with clean water before being sprayed on the coal surface.

9. The method for suppressing mud formation in the coal washing process according to any one of claims 1 to 8, characterized in that: The preparation method of the mud inhibitor comprises the following steps: S1. Add the sodium hexametaphosphate to be dissolved into a mixing tank filled with warm water, stir evenly in the warm water, heat the water to 70°C-80°C and continue stirring until the sodium hexametaphosphate is completely dissolved, add sodium oleate, and then stir. S2. Add stabilizer, antioxidant, surfactant and emulsifier into the mixing tank in sequence, and continue heating and stirring for 2 hours to mix them completely. S3. After the mixed liquid is cooled to room temperature, it is evenly sprayed on the surface of the coal through a spray system installed above the coal conveying mechanism.

10. The method for suppressing mud formation during coal washing according to claim 9, characterized in that: After sodium oleate is added to S1, the stirring time is 3-5 hours, and the temperature is maintained at 30-50°C during the stirring process.

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