Method for grinding slurry of waxy hazardous waste and coal water slurry

Abstract

The application provides a grinding and slurry-making method for waxy hazardous waste, comprising the following steps: S1, mixing coal, water and an additive and performing first grinding to obtain a first slurry; S2, mixing the waxy hazardous waste with water, performing second grinding, continuously adding a viscosity reducer to the system during the second grinding, and obtaining a second slurry, wherein the total amount of the viscosity reducer is 0.5-1.0% of the weight of the waxy hazardous waste; S3, performing filtration treatment on the second slurry to obtain waste particles and a primary treatment waste slurry, and screening the waste particles to obtain a part with a mass ratio of 180-200 mesh particles of greater than or equal to 70% as primary treatment waste particles; and S4, mixing the primary treatment waste particles, the primary treatment waste slurry and the first slurry to obtain a coal-water slurry. The method provided by the application solves the problem of adhesion of the waxy hazardous waste to the grinding machine due to softening caused by heating during the grinding process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal water slurry preparation, in particular to a grinding and slurry-making method of wax-containing hazardous waste and coal water slurry. BACKGROUND

[0002] Wax-containing waste such as stabilized wax, residue wax and the like is prone to self-ignition due to heat accumulation for a long time in the air, and poses a hazard to the surrounding environment and human health. The heat is high, and a large amount of paraffin resources are contained, so the wax-containing waste is defined as hazardous waste, which needs to be treated by special environmental protection enterprises. However, the treatment of the wax-containing waste is difficult, the single treatment amount is small, and the cost is high. At present, the treatment method of most wax-containing hazardous waste is incineration, which cannot realize resource utilization.

[0003] In the industry, hazardous waste is blended with coal to prepare environmentally friendly coal water slurry, which can be used as a gasification furnace or a boiler raw material, or can provide a reference for the treatment of wax-containing hazardous waste. In the preparation process of the coal water slurry, the hazardous waste is first ground to a certain particle size, and the hazardous waste that can be used to prepare environmentally friendly coal water slurry can be ground without limitation to achieve the required particle size, or the hazardous waste is in a fluid state and can be directly mixed. However, in the grinding process, heat is generated, the wax-containing hazardous waste has the characteristic of softening under heat, and the equipment is adhered during the grinding process, which cannot achieve unlimited grinding. At the same time, it is a solid hazardous waste and cannot be directly mixed as a fluid waste.

[0004] In order to make up for the above shortcomings, there is an urgent need in the art to provide a grinding and slurry-making method of wax-containing hazardous waste to solve the problems of adhesion of the wax-containing hazardous waste to the grinding machinery due to softening under heat and poor stability of the wax-containing hazardous waste and coal in the prior art. SUMMARY

[0005] The main purpose of the present application is to provide a grinding and slurry-making method of wax-containing hazardous waste and coal water slurry to solve the problems of adhesion of the wax-containing hazardous waste to the grinding machinery due to softening under heat and poor stability of the wax-containing hazardous waste and coal in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present application provides a method for grinding and slurry-making of waxy hazardous waste in one aspect, comprising the following steps: step S1, mixing coal, water and additives and performing first grinding to obtain a first slurry; step S2, mixing the waxy hazardous waste with water, performing second grinding, and continuously adding a viscosity reducer to the system during the second grinding to obtain a second slurry, the total amount of the viscosity reducer being 0.5-1.0% of the weight of the waxy hazardous waste; step S3, filtering the second slurry to obtain waste particles and a primary treatment waste slurry; screening the waste particles to obtain a part with a mass ratio of 180-200 mesh particles of 70% or more as primary treatment waste particles; and step S4, mixing the primary treatment waste particles, the primary treatment waste slurry and the first slurry to obtain a coal-water slurry.

[0007] Further, the viscosity reducer is added in the form of an aqueous solution in step S2, and the aqueous solution of the viscosity reducer is added within 2-8 min.

[0008] Further, the particle size distribution of the primary treatment waste particles is, in terms of weight parts, 15-25 parts of particles larger than 200 mesh, 70-80 parts of 180-200 mesh particles, and 4-6 parts of 80-180 mesh particles.

[0009] Further, the mixture of the waxy hazardous waste and water is pre-cooled before the second grinding in step S2; preferably, the temperature of the cooled mixture is 10-20℃.

[0010] Further, the viscosity reducer is selected from one or more of sodium dodecyl benzene sulfonate, OP-10, sodium p-styrenesulfonate and sodium polyoxyethylene ether sulfate; preferably, the viscosity reducer is a combination of sodium dodecyl benzene sulfonate and OP-10; more preferably, the weight ratio of sodium dodecyl benzene sulfonate to OP-10 in the viscosity reducer is (4-8):(1-3).

[0011] Further, the solid content of the second slurry is 55-65%.

[0012] Further, the solid content of the first slurry is 55-69%; and the particle size distribution of the solid particles in the first slurry is, in terms of weight parts, 45-55 parts of particles larger than 200 mesh, 8-12 parts of 100-200 mesh particles, 25-35 parts of 60-100 mesh particles, and 8-12 parts of 40-60 mesh particles.

[0013] Further, the additive in step S1 is sodium lignosulfonate; preferably, the amount of the additive is 2.0-3.0% of the weight of the coal.

[0014] Further, the solid content of the coal-water slurry is 55-65%; and the weight ratio of the primary treatment waste particles to the coal in the coal-water slurry is 1:(8-12).

[0015] Another aspect of the present application provides a coal water slurry prepared by the above method; the viscosity of the coal water slurry at room temperature is 384.0-490.0 mPa·s, and the Zeta potential is -39.8--21.5 mV.

[0016] By applying the technical solution of the present application, the waste is used to replace the raw coal, thereby reducing the amount of raw coal in the preparation process of the coal water slurry; by continuously adding the viscosity reducer during the grinding process of the wax-containing hazardous waste, the adhesion of the wax-containing hazardous waste to the grinding machinery due to softening caused by heating during the grinding process is solved, thereby improving the slurryability and stability of the wax-containing hazardous waste and the coal in the slurry preparation. DETAILED DESCRIPTION

[0017] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0018] As described in the background, there are problems of adhesion of the wax-containing hazardous waste to the grinding machinery due to softening caused by heating during the grinding process and poor stability of the wax-containing hazardous waste and the coal in the slurry preparation in the prior art. In order to solve the above technical problems, the present application provides a method for grinding and slurry preparation of wax-containing hazardous waste, which includes the following steps: step S1, mixing coal, water and additives and performing first grinding to obtain a first slurry; step S2, mixing the wax-containing hazardous waste with water and performing second grinding, and continuously adding a viscosity reducer to the system during the second grinding, to obtain a second slurry, the total amount of the viscosity reducer being 0.5-1.0% of the weight of the wax-containing hazardous waste; step S3, filtering the second slurry to obtain waste particles and a preliminary treated waste slurry; screening the waste particles to obtain a part with a mass fraction of 180-200 mesh particles being greater than or equal to 70% as the preliminary treated waste particles; and step S4, mixing the preliminary treated waste particles, the preliminary treated waste slurry and the first slurry to obtain a coal water slurry.

[0019] The present application uses the wax-containing hazardous waste to replace part of the raw coal, thereby reducing the amount of raw coal in the preparation process of the coal water slurry. At the same time, by using the above specific preparation process, the slurryability and stability of the wax-containing hazardous waste and the coal in the slurry preparation are improved.

[0020] In step S1, the coal raw material is first ground to obtain a coal slurry dispersion liquid with reasonable particle size distribution, which is convenient for mixing and dispersion with the subsequent wax-containing hazardous waste.

[0021] The wax-containing hazardous waste is ground in step S2. Due to the high content of heavy hydrocarbon in the wax-containing hazardous waste and the complex components, the wax-containing hazardous waste is prone to softening and adhering to the grinding machine during the grinding process. In the present application, a viscosity reducer is continuously added during the grinding process to solve the above-mentioned adhesion problem, so that the grinding process can be more sufficient, and waste particles with a particle size that can better adapt to the coal raw material particles are obtained. At the same time, due to the high content of wax in the wax-containing hazardous waste, the wax-containing hazardous waste has high hydrophobicity, which leads to poor slurryability when the wax-containing hazardous waste is slurried with coal. In the present application, the hydrophilicity of the wax-containing hazardous waste is gradually increased during the grinding process by continuously adding a viscosity reducer, thereby improving the subsequent slurryability of the wax-containing hazardous waste with coal. In addition, the total amount of the viscosity reducer added is controlled to be 0.5-1.0% of the weight of the wax-containing hazardous waste. Compared with a larger amount of the viscosity reducer, the stability of the wax-containing hazardous waste particles and the final water-coal slurry is improved under the conditions of solving the adhesion problem and improving the slurryability, while the preparation cost of the water-coal slurry is reduced, and the economic benefit is improved. It is also necessary to specially point out that, compared with adding the viscosity reducer at one time, the present application continuously adds the viscosity reducer to the system during the grinding process, which promotes the gradual grinding process and makes the waste particles more uniform and the hydrophilicity more significantly improved. This is also a key operation to ensure the slurryability of the final water-coal slurry.

[0022] Step S3 is to filter the obtained second slurry containing wax-containing hazardous waste particles, thereby obtaining waste particles with different particle size distributions. Through a large number of experiments, the inventors reasonably combine and proportion the obtained waste particles with different particle size distributions, and obtain a part with a particle size of 180-200 mesh and a mass proportion of ≥70% as the preliminary treated waste particles. The preliminary treated waste particles with this particle size distribution can better adapt to the coal raw material particles in the first slurry, thereby improving the slurryability of the two and the stability of the obtained water-coal slurry.

[0023] In step S4, the preliminary treated waste particles obtained by screening, the preliminary treated waste slurry and the first slurry are mixed to obtain a water-coal slurry. At this time, the preliminary treated waste slurry still contains a small amount of viscosity reducer that has not been used for viscosity reduction. This part of the viscosity reducer can be added as an additive into the final water-coal slurry system with the preliminary treated waste slurry, and further play a role as a dispersant in the system, thereby further controlling the preparation cost of the obtained water-coal slurry while improving the dispersibility, uniformity and stability of the water-coal slurry. The water in the preliminary treated waste slurry can also be used as water for dispersion and slurry formation, thereby reducing the water consumption during the slurry preparation process, so as to further reduce the production and preparation cost.

[0024] The preparation method provided by the application can realize the reuse of the wax-containing hazardous waste, reduce the damage to the surrounding environment caused by the accumulation of the hazardous waste, and reduce the amount of raw coal in the preparation process of the coal water slurry, thereby comprehensively reducing the cost and improving the economic benefit in the treatment of hazardous waste and the preparation of the coal water slurry.

[0025] Specifically, the raw coal used in the application is Yangchangwan coal, and the wax-containing hazardous waste is a waste catalyst generated in a Fischer-Tropsch synthesis process, wherein the wax content is 50-60%, and 30% is inorganic matter in the catalyst.

[0026] In addition, the grinding in the application is wet grinding, which is realized by a sealed sample preparation machine, and the speed in the grinding process is 800-1200 r / min.

[0027] In a preferred embodiment, the viscosity reducer in step S2 is added in the form of an aqueous solution, and the aqueous solution of the viscosity reducer is added within 2-8 min, and the aqueous solution of the viscosity reducer is continuously added in the form of a stream during the grinding process, instead of dissolving the viscosity reducer in the water phase containing the wax-containing hazardous waste, which can help to form a dynamic viscosity reduction process, enhance the contact between the surface of the wax-containing hazardous waste particles and the molecules of the viscosity reducer, improve the utilization rate of the added viscosity reducer, and more effectively avoid the agglomeration and softening of the wax-containing hazardous waste during the grinding process, thereby better improving the adhesion of the wax-containing hazardous waste to the grinding machinery due to the softening caused by heating during the grinding process, making the grinding more sufficient, obtaining the wax-containing hazardous waste particles better adapted to the particle size of the coal particles in the first slurry, and thereby improving the synergistic slurry forming property of the two.

[0028] As described above, in order to better adapt to the particle size of the coal particles in the first slurry, thereby improving the slurry forming property and stability of the subsequent coal water slurry, in a preferred embodiment, the particle size distribution of the preferred primary waste particles is as follows: greater than 200 mesh, 15-25 parts by weight; 180-200 mesh, 70-80 parts by weight; 80-180 mesh, 4-6 parts by weight; and correspondingly, the particle size distribution of the solid particles in the first slurry, i.e. the coal particles, is as follows: greater than 200 mesh, 45-55 parts by weight; 100-200 mesh, 8-12 parts by weight; 60-100 mesh, 25-35 parts by weight; 40-60 mesh, 8-12 parts by weight. Selecting the particle size distribution of the two components within the above range can make the particle size of the two components better adapted to each other during the slurry forming process, thereby facilitating the smooth progress of the slurry forming process of the coal water slurry, improving the stability, uniformity and combustion characteristics of the final obtained coal water slurry, and reducing the possibility of hard precipitation.

[0029] Further, before the second grinding, the step S2 also includes pre-cooling the mixed system of the wax-containing hazardous waste and water; preferably, the temperature of the mixed system after cooling is 10-20℃. At this lower temperature of 10-15℃, more wax crystal particles can be precipitated from the wax-containing hazardous waste, which is conducive to the eutectic effect of the viscosity reducer and the wax-containing hazardous waste, so as to further enhance the viscosity reduction effect of the viscosity reducer, so as to better improve the adhesion of the wax-containing hazardous waste to the grinding machinery due to softening caused by heating during the grinding process, improve the subsequent slurry forming property and stability of the wax-containing hazardous waste with coal, and reduce the viscosity of the obtained coal water slurry.

[0030] In several typical embodiments, the viscosity reducer is selected from one or more of sodium dodecyl benzene sulfonate, OP-10, sodium p-styrenesulfonate, and sodium polyoxyethylene ether sulfate. The viscosity reducer can in principle be selected from the types commonly used in the art, but in a preferred embodiment, when the viscosity reducer is a combination of sodium dodecyl benzene sulfonate and OP-10, better viscosity reduction effect can be achieved, so that the grinding of the wax-containing hazardous waste is more complete, and the adhesion of the wax-containing hazardous waste to the grinding machinery due to softening caused by heating during the grinding process is avoided, hindering the smooth progress of the grinding process; on this basis, more preferably, the weight ratio of sodium dodecyl benzene sulfonate to OP-10 in the viscosity reducer is (4-8):(1-3), which can better match the polar groups in the wax component of the wax-containing hazardous waste, thereby improving the viscosity reduction effect and more effectively solving the adhesion problem of the wax-containing hazardous waste to the grinding machinery due to softening caused by heating during the grinding process.

[0031] In order to make the grinding process of the wax-containing hazardous waste more complete and obtain wax-containing hazardous waste particles with a particle size distribution that better matches coal particles, in a typical embodiment, the solid content of the second slurry is selected to be 55-65%, and the second slurry at this solid content can achieve more complete grinding and promote the viscosity reduction effect of the viscosity reducer, thereby improving the adhesion problem and obtaining wax-containing hazardous waste particles with a more reasonable particle size distribution.

[0032] Correspondingly, in order to improve the slurry forming property and dispersion uniformity of the final obtained coal water slurry, the solid content of the first slurry is selected to be 55-69%, so that the first slurry can use this solid content as the base slurry to provide good prerequisites during the slurry forming process of the coal water slurry, thereby facilitating the obtaining of a coal water slurry with good slurry forming property and stability.

[0033] In order to make the raw coal particles better dispersed, preferably, in step S1, the additive is selected as sodium lignosulfonate as a dispersant, and compared with the dispersants commonly used in the art, such as hexadecyl trimethyl ammonium bromide, sodium carboxymethyl cellulose and sodium lauryl sulfate, sodium lignosulfonate is cheaper in price, so that the production and preparation cost of the coal water slurry can be reduced while the coal water slurry is obtained, and the product added value is improved. In a typical embodiment, the amount of the additive is selected to be 2.0-3.0% by weight of the coal, so as to achieve a better dispersion effect, thereby providing a good basis for finally obtaining a coal water slurry with good stability and low viscosity.

[0034] In a preferred embodiment, the solid content of the obtained coal water slurry is 55-65%, and the weight ratio of the primary treatment waste particles to the coal in the coal water slurry is 1:(8-12), the coal water slurry obtained by the present application has a higher waste mixing ratio, which can comprehensively reduce the treatment cost of the wax-containing hazardous waste and the preparation cost of the produced coal water slurry, thereby improving the economic benefit.

[0035] Another aspect of the present application provides a coal water slurry prepared by the above method; the viscosity of the coal water slurry at room temperature is 384.0-490.0 mPa·s, that is, the viscosity of the coal water slurry obtained by the present application is lower; the Zeta potential refers to the electrostatic potential on the surface of the suspended particles in the liquid, which is used to indicate the repulsive force between the particles in the suspension, and then predict the influence of colloidal dispersion on particle aggregation, the greater the absolute value, the stronger the electrostatic repulsion, which is beneficial to the stability of the suspension; the Zeta potential of the coal water slurry obtained by the present application is-39.8--21.5 mV, that is, it has strong stability.

[0036] The present application will be further described in detail below in conjunction with specific embodiments, which cannot be understood as limiting the scope of the present application.

[0037] Unless otherwise defined, all the professional terms used below have the same meaning as generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present application.

[0038] Example 1

[0039] A grinding and slurry-making method for wax-containing hazardous waste:

[0040] (1) 200 g of raw coal, water and 5 g of sodium lignosulfonate are ground until the particle size distribution is 50 parts of greater than 200 mesh, 10 parts of 200-100 mesh, 30 parts of 100-60 mesh, and 10 parts of 60-40 mesh (by weight), to obtain a first slurry with a solid content of 65%;

[0041] (2) 20 g of the wax-containing hazardous waste was mixed with water to obtain a mixed system, and the mixed system was cooled to 12℃, and then a second grinding was performed, and during the grinding, an aqueous solution of a combination of sodium dodecyl benzene sulfonate and OP-10 was added to the mixed system as a viscosity reducer, the aqueous solution of the combination of sodium dodecyl benzene sulfonate and OP-10 was 0.16 g of sodium dodecyl benzene sulfonate and 0.04 g of OP-10 (i.e. the weight ratio of the two was 4:1, and the total weight of the two was 1% of the wax-containing hazardous waste), the mass concentration of the added aqueous solution of the viscosity reducer combination was 1.4%, and a second slurry with a solid content of 65% was obtained;

[0042] (3) The solid particles in the second slurry were filtered to obtain a waste liquid and solid particles, and then the solid particles were sieved with 60 mesh, 180 mesh and 200 mesh sieves in sequence to obtain hazardous waste particles with different particle size distributions, and the particle size distribution of the used wax-containing hazardous waste particles was 20 parts of greater than 200 mesh, 75 parts of 200-180 mesh, and 5 parts of less than 180 mesh;

[0043] (4) The waste liquid obtained by filtration, the used wax-containing hazardous waste particles, and the first slurry were mixed to obtain a coal-water slurry with a solid content of 60.3%, and the weight ratio of the wax-containing hazardous waste particles to the coal particles in the coal-water slurry was 1:10.

[0044] Example 2

[0045] A grinding and slurry-making method for a wax-containing hazardous waste:

[0046] The difference between this example and Example 1 is that the addition time of the aqueous solution of the viscosity reducer is 2 min.

[0047] Example 3

[0048] A grinding and slurry-making method for a wax-containing hazardous waste:

[0049] The difference between this example and Example 1 is that the addition time of the aqueous solution of the viscosity reducer is 8 min.

[0050] Example 4

[0051] A grinding and slurry-making method for a wax-containing hazardous waste:

[0052] The difference between this example and Example 1 is that the addition time of the aqueous solution of the viscosity reducer is 30 s.

[0053] Example 5

[0054] A grinding and slurry-making method for a wax-containing hazardous waste:

[0055] The difference between this example and Example 1 is that the addition time of the aqueous solution of the viscosity reducer is 10 min.

[0056] Example 6

[0057] A method for grinding and pulping a wax-containing hazardous waste:

[0058] The difference between this embodiment and embodiment 1 is that the particle size distribution of the hazardous waste particles to be used is different, in parts by weight, greater than 200 mesh: 10 parts, 200-180 mesh: 90 parts, and less than 180 mesh: 0 parts.

[0059] Embodiment 7

[0060] A method for grinding and pulping a wax-containing hazardous waste:

[0061] The difference between this embodiment and embodiment 1 is that the grinding is started at room temperature, i.e., the mixture of the wax-containing hazardous waste and water is not cooled before grinding.

[0062] Embodiment 8

[0063] A method for grinding and pulping a wax-containing hazardous waste:

[0064] The difference between this embodiment and embodiment 1 is that the sodium dodecyl benzene sulfonate in the viscosity reducer composition is 0.1 g, and the OP-10 is 0.1 g (i.e., the weight ratio of the two is 1:1).

[0065] Embodiment 9

[0066] A method for grinding and pulping a wax-containing hazardous waste:

[0067] The difference between this embodiment and embodiment 1 is that the sodium dodecyl benzene sulfonate in the viscosity reducer composition is 0.05 g, and the OP-10 is 0.15 g (i.e., the weight ratio of the two is 1:3).

[0068] Embodiment 10

[0069] A method for grinding and pulping a wax-containing hazardous waste:

[0070] The difference between this embodiment and embodiment 1 is that only 0.2 g of OP-10 is used as the viscosity reducer.

[0071] Embodiment 11

[0072] A method for grinding and pulping a wax-containing hazardous waste:

[0073] The difference between this embodiment and embodiment 1 is that only 0.2 g of sodium dodecyl benzene sulfonate is used as the viscosity reducer.

[0074] Embodiment 12

[0075] A method for grinding and pulping a wax-containing hazardous waste:

[0076] The difference between this embodiment and embodiment 1 is that the solid content of the second slurry is 70%.

[0077] Example 13

[0078] A method for preparing a slurry of a hazardous waste containing wax by grinding:

[0079] This example differs from Example 1 in that the solid content of the second slurry is 50%.

[0080] Example 14

[0081] A method for preparing a slurry of a hazardous waste containing wax by grinding:

[0082] This example differs from Example 1 in that the solid content of the first slurry is 50%, and the particle size distribution of the solid particles is 40 parts of 200 mesh or more, 5 parts of 200 to 100 mesh, 40 parts of 100 to 60 mesh, and 15 parts of 60 to 40 mesh (by weight).

[0083] Example 15

[0084] A method for preparing a slurry of a hazardous waste containing wax by grinding:

[0085] This example differs from Example 1 in that the solid content of the first slurry is 72.5%, and the particle size distribution of the solid particles is 60 parts of 200 mesh or more, 15 parts of 200 to 100 mesh, 20 parts of 100 to 60 mesh, and 5 parts of 60 to 40 mesh (by weight).

[0086] Example 16

[0087] A method for preparing a slurry of a hazardous waste containing wax by grinding:

[0088] This example differs from Example 1 in that a composition of hexadecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate, and sodium carboxymethylcellulose (hexadecyltrimethylammonium bromide:sodium dodecylbenzenesulfonate:sodium carboxymethylcellulose = 4:3:3 by weight) is used as an additive during grinding of the coal raw material, and the weight ratio of the composition to the coal raw material is 0.1:50.

[0089] Example 17

[0090] A method for preparing a slurry of a hazardous waste containing wax by grinding:

[0091] This example differs from Example 1 in that the solid content of the obtained coal water slurry is 50%, and the weight ratio of the hazardous waste containing wax particles to the coal particles is 1:5.

[0092] Example 18

[0093] A method for preparing a slurry of a hazardous waste containing wax by grinding:

[0094] The difference between this embodiment and embodiment 1 is that the solid content of the obtained coal water slurry is 70%, and the weight ratio of the wax-containing hazardous waste particles to the coal particles is 1:15.

[0095] Comparative example 1

[0096] A grinding slurry method of a wax-containing hazardous waste:

[0097] The difference between this embodiment and embodiment 1 is that the particle size distribution of the hazardous waste particles to be used is different, and in terms of weight parts, the particle size greater than 200 mesh is 30 parts, the particle size of 200-180 mesh is 60 parts, and the particle size less than 180 mesh is 10 parts.

[0098] Comparative example 2

[0099] A grinding slurry method of a wax-containing hazardous waste:

[0100] The difference between this embodiment and embodiment 1 is that the raw coal, water, sodium lignosulfonate, and the wax-containing hazardous waste are directly mixed and ground, and the grinding time is 5 min, and the aqueous solution of the combination of sodium dodecyl benzene sulfonate and OP-10 is continuously added as a viscosity reducer during the grinding process to obtain a coal water slurry.

[0101] Comparative example 3

[0102] A grinding slurry method of a wax-containing hazardous waste:

[0103] The difference between this embodiment and embodiment 1 is that the raw coal, water, sodium lignosulfonate, and the wax-containing hazardous waste are directly mixed and ground, and the grinding time is 8 min to obtain a coal water slurry.

[0104] Comparative example 4

[0105] A grinding slurry method of a wax-containing hazardous waste:

[0106] The difference between this embodiment and embodiment 1 is that in step (2), the operation of continuously adding the viscosity reducer during the grinding process is not used, but the wax-containing hazardous waste is directly added to the aqueous solution containing the viscosity reducer and ground.

[0107] Comparative example 5

[0108] A grinding slurry method of a wax-containing hazardous waste:

[0109] The difference between this embodiment and embodiment 1 is that in step (2), the total amount of the viscosity reducer added is 0.1% of the weight of the wax-containing hazardous waste.

[0110] Comparative example 6

[0111] A grinding slurry method of a wax-containing hazardous waste:

[0112] The difference between this embodiment and embodiment 1 is that no viscosity reducer is added in step (2).

[0113] Comparative example 7

[0114] A grinding method for preparing a slurry of a waxy hazardous waste:

[0115] The difference between this embodiment and embodiment 1 is that in step (3), the second slurry is not filtered and screened, but is directly mixed with the first slurry to obtain the coal water slurry.

[0116] Results test:

[0117] Adhesion of the waxy hazardous waste: the ratio of the residual amount of the material in the grinding instrument after grinding to the added amount of the material before grinding is used for evaluation.

[0118] Zeta potential: the Zeta potential is measured by using a Zeta potential instrument Litesizer 500 at a temperature of 25℃ by electrophoretic light scattering method, and deionized water is used to dilute the slurry to 0.2-0.3% before measurement to ensure that the transmittance is greater than 10%; the sample cell is first rinsed before loading the sample.

[0119] The performance test results of the above embodiments are shown in Table 1.

[0120] Table 1

[0121]

[0122]

[0123] From the above description, it can be seen that the above-mentioned embodiments of the present application solve the problem of adhesion of the waxy hazardous waste to the grinding machine due to softening caused by heating during the grinding process, thereby improving the slurryability and stability of the waxy hazardous waste and coal co-slurry. The obtained coal water slurry has low viscosity, high stability and low preparation cost, and can well meet the storage, transportation and preparation requirements.

[0124] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that described herein.

[0125] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for grinding and pulping wax-containing hazardous waste, characterized in that, The grinding and pulping method for the wax-containing hazardous waste includes the following steps: Step S1: Mix coal, water and additives and perform a first grinding to obtain a first slurry; Step S2: Mix the wax-containing hazardous waste with water and perform a second grinding. During the second grinding process, continuously add a viscosity reducer to the system to obtain a second slurry. The total amount of the viscosity reducer added is 0.5 to 1.0% of the weight of the wax-containing hazardous waste. The viscosity reducer is added in the form of an aqueous solution, and the aqueous solution of the viscosity reducer is added within 2 to 8 minutes. Step S3: The second slurry is filtered to obtain waste particles and pre-treated waste slurry. The waste particles are sieved to obtain a portion with a mass ratio of ≥70% of 180-200 mesh particles as pre-treated waste particles. By weight, the particle size distribution of the pre-treated waste particles is as follows: greater than 200 mesh, 15-25 parts; 180-200 mesh, 70-80 parts; 80-180 mesh, 4-6 parts. Step S4: Mix the pre-treated waste particles, the pre-treated waste slurry, and the first slurry to obtain a coal-water slurry.

2. The grinding and pulping method for wax-containing hazardous waste according to claim 1, characterized in that, Before the second grinding, step S2 also includes pre-cooling the mixture of the waxy hazardous waste and water.

3. The grinding and pulping method for wax-containing hazardous waste according to claim 2, characterized in that, The temperature of the mixture after cooling is 10~20℃.

4. The grinding and pulping method for wax-containing hazardous waste according to claim 1, characterized in that, The viscosity reducer is selected from one or more of sodium dodecylbenzenesulfonate, OP-10, sodium p-styrenesulfonate, and sodium polyoxyethylene ether sulfate.

5. The grinding and pulping method for wax-containing hazardous waste according to claim 4, characterized in that, The viscosity reducer is a combination of sodium dodecylbenzenesulfonate and OP-10.

6. The grinding and pulping method for wax-containing hazardous waste according to claim 5, characterized in that, The weight ratio of sodium dodecylbenzenesulfonate to OP-10 in the viscosity reducer is (4~8):(1~3).

7. The grinding and pulping method for wax-containing hazardous waste according to any one of claims 1 to 4, characterized in that, The solid content of the second slurry is 55-65%.

8. The grinding and pulping method for wax-containing hazardous waste according to any one of claims 1 to 4, characterized in that, The solid content of the first slurry is 55-69%; by weight, the particle size distribution of the solid particles in the first slurry is as follows: greater than 200 mesh, 45-55 parts; 100-200 mesh, 8-12 parts; 60-100 mesh, 25-35 parts; 40-60 mesh, 8-12 parts.

9. The grinding and pulping method for wax-containing hazardous waste according to any one of claims 1 to 4, characterized in that, The additive mentioned in step S1 is sodium lignosulfonate.

10. The grinding and pulping method for wax-containing hazardous waste according to claim 9, characterized in that, The amount of the additive is 2.0 to 3.0% of the weight of the coal.

11. The grinding and pulping method for wax-containing hazardous waste according to any one of claims 1 to 4, characterized in that, The solid content of the coal-water slurry is 55-65%; and the weight ratio of the primary treatment waste particles to the coal in the coal-water slurry is 1:(8-12).

12. A coal-water slurry, characterized in that, The water-coal slurry is prepared by any one of claims 1 to 11; the viscosity of the water-coal slurry at room temperature is 384.0~490.0 mPa·s, and the Zeta potential is -39.8~-21.5 mV.

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