Method for preparing slurry by adding auxiliaries through multi-stage method

Abstract

The invention discloses a method for preparing slurry by adding auxiliaries through a multi-stage method, which is a method for adding auxiliaries of different types and dosages into a stirring tank before raw materials enter a mill, a feeding section of the mill and an outlet of the mill on the basis of research on a slurry grinding process. The auxiliary is added by a multi-stage method, so that the dispersion state of particles can be improved in the slurry preparation process, and the particle size distribution, rheological property, constant viscosity concentration and stability of the slurry are optimized; the device can be suitable for mixed pulping of various raw materials; the method is convenient to operate, low in cost, good in effect and high in application and popularization value.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and particularly relates to a method for preparing slurry by adding additives in a multi-stage process, in particular to a method for manufacturing water-coal slurry, water-coke slurry and multi-component slurry. Background Art

[0002] At present, water-coal slurry technology is used to treat a variety of wastes, such as oil sludge, sludge, coal chemical waste residue, semi-coke, etc. Due to the different physical and chemical properties of various materials, in order to disperse raw materials of different properties and achieve effective grinding of various raw materials at the same time, the commonly used methods to improve slurry performance include improving dispersant performance, adding stabilizers, and using a combination of multiple grinding methods. However, these methods cannot solve the dispersion of particles of different properties, the dispersion of particles at different stages, and effective grinding at the same time.

[0003] Chinese invention patent application CN202411087950.2 proposes a method for synthesizing two hydrophilic long side chain end groups with aromatic structures using acrylic acid, sodium styrene sulfonate, and BNO / AE. This method provides a method for synthesizing additives that can efficiently increase the concentration of water-coal slurry, but this type of additive cannot disperse oil sludge, sludge, etc., and cannot avoid problems such as reverse adsorption of particles to dispersants.

[0004] Chinese invention patent application CN202410733732.5 proposes a multi-bin and multi-grinding medium combination mill for efficiently preparing fine slurry. This method can save energy, reduce grinding medium loss, shorten grinding time, and improve grinding efficiency. At the same time, a higher concentration of fine slurry can be obtained, and its process is simple, easy to operate, and the device cost is low. Although this device can improve the preparation process of water-coal slurry and can more effectively improve the particle size distribution, it cannot avoid the problem of reverse adsorption of particles to dispersants, and multi-component slurry cannot be effectively dispersed under intense grinding conditions.

[0005] Chinese invention patent CN202311762848.3 proposes a grinding and pulping method for wax-containing hazardous waste. The wax-containing hazardous waste adheres to the grinding machinery due to heat softening during the grinding process. The wax-containing waste liquid is first pulped and then mixed with water-coal slurry. The wax-containing hazardous waste adheres to the grinding machinery due to heat softening during the grinding process, and the dispersion problem of wax-containing hazardous waste is solved, but the problem of effective grinding of different raw materials cannot be solved, so the slurry performance cannot be improved.

[0006] In summary, the above methods are unable to solve the problem of co-slurrying of multiple slurries and simultaneously solve the problem of particle dispersion and grinding effect. Summary of the invention

[0007] In order to solve the problems in the prior art, the present invention provides a method for preparing slurry by adding additives in a multi-stage method, which is used to manufacture water-coal slurry, water-coke slurry, water-gasification waste residue-coal slurry, and oil sludge-coal-water slurry.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A method for preparing slurry by adding additives in a multi-stage process, when preparing water-coal slurry, water-coke slurry, water-gasification waste residue-coal slurry, comprises the following steps:

[0010] S2. At the mill inlet, adding a dispersant I which is beneficial to the dispersion of coal organic matter into the liquid raw material, wherein the amount of the dispersant I is 40-80% of the total dispersant weight;

[0011] S3. At the mill outlet, add dispersant II which is beneficial to the dissociation of clay inorganic substances, and the amount of dispersant II is 60-20% of the total dispersant weight.

[0012] S4. In the stirring barrel at the mill outlet, add a stabilizer that is beneficial to the slurry stability and a viscosity reducer that is beneficial to the viscosity reduction. The amount of stabilizer (on a dry basis) is 20-500ppm of the total slurry of the liquid raw material, and the amount of viscosity reducer (on a dry basis) is 50-100ppm of the total slurry of the liquid raw material.

[0013] Further, the liquid raw material is oily wastewater, and the liquid raw material is water-coal slurry, water-coal-coke slurry, water-coal slag slurry or coal-water-oil slurry;

[0014] Furthermore, when the liquid raw material is water-coal slurry, water-coal-coke slurry, water-coal-ash slurry or coal-water-oil slurry, the method for preparing the slurry includes steps S2-S3 or S2-S4.

[0015] Further, the dispersant I is any one of a naphthalene dispersant, an aliphatic dispersant, and a lignin dispersant, or a mixture of any two or three thereof; preferably, naphthalenesulfonic acid formaldehyde copolymer sodium salt (NSF), sodium lignin sulfonate (LS), or sulfonated acetone formaldehyde copolymer (SAF) is selected.

[0016] Furthermore, the dispersant II is sodium hexametaphosphate or sodium metasilicate and dispersant I (NSF, LS, SAF).

[0017] Further, the stabilizer is sodium carboxymethylcellulose (CMC) solution or xanthan gum (TS) solution;

[0018] Furthermore, the viscosity reducing agent is sodium polyacrylate (PAA), sodium metasilicate or sodium hexametaphosphate.

[0019] Furthermore, the mill outlet is on a vibrating screen or an outlet drum screen.

[0020] A method for preparing slurry by adding additives in a multi-stage method, when preparing oil sludge-coal-water slurry, comprises the following steps:

[0021] S1. Add an emulsifier into a liquid raw material feeding stirring tank to fully emulsify the liquid raw material. The amount of the emulsifier is 0.15-2.0% by weight of the total slurry of the liquid raw material, and then proceed to steps S2-S4.

[0022] S2. At the mill inlet, adding a dispersant I which is beneficial to the dispersion of coal organic matter into the liquid raw material, wherein the amount of the dispersant I is 40-80% of the total dispersant weight;

[0023] S3. At the mill outlet, add dispersant II which is beneficial to the dissociation of clay inorganic substances, and the amount of dispersant II is 60-20% of the total dispersant weight.

[0024] S4. In the stirring barrel at the mill outlet, add a stabilizer that is beneficial to the slurry stability and a viscosity reducer that is beneficial to the viscosity reduction. The amount of stabilizer (on a dry basis) is 20-500ppm of the total slurry of the liquid raw material, and the amount of viscosity reducer (on a dry basis) is 50-100ppm of the total slurry of the liquid raw material.

[0025] Furthermore, when the liquid raw material in step S1 is oil sludge-coal-water slurry, an emulsifier (Tween 80 (TW80) or Tween 60 (TW80)) is added in an amount of 0.15 to 0.5% of the total mass of the oil sludge into a pre-mixing barrel to pre-emulsify the oil sludge, and the emulsified oil sludge, coal, water and coal-water slurry additives (dispersant I, dispersant II, stabilizer and viscosity reducer) are added into a ball mill to obtain an oil sludge-coal-water slurry with good fluidity and stability.

[0026] Furthermore, the emulsifier is Tween or polyoxyethylene ether.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1) The present invention does not require any improvement to the existing pulping system;

[0029] 2) The present invention is aimed at the different grindability and dispersibility of various pulping raw materials, and the goal is clear;

[0030] 3) The present invention is easy to operate, has low production cost, and has high promotion and application value. The present invention improves the fluidity and stability of multi-component slurries such as water-coal slurry, reduces the amount of additives used, and increases the fixed viscosity concentration of the slurry. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments.

[0032] A method for preparing slurry by adding additives in a multi-stage process, when preparing water-coal slurry, water-coke slurry, water-gasification waste residue-coal slurry, comprises the following steps:

[0033] S2. At the mill inlet, adding a dispersant I which is beneficial to the dispersion of coal organic matter into the liquid raw material, wherein the amount of the dispersant I is 40-80% of the total dispersant weight;

[0034] S3. Add dispersant II at the mill outlet (on the vibrating screen or outlet drum screen) which is beneficial to the dissociation and dispersion of clay inorganic substances. The amount of dispersant II is 60-20% of the total dispersant weight.

[0035] S4. In the stirring barrel at the mill outlet, add a stabilizer that is beneficial to the slurry stability and a viscosity reducer that is beneficial to the viscosity reduction. The amount of stabilizer (on a dry basis) is 20-500ppm of the total slurry of the liquid raw material, and the amount of viscosity reducer (on a dry basis) is 50-100ppm of the total slurry of the liquid raw material.

[0036] When the liquid raw material is water-coal slurry, water-coal-coke slurry, water-coal ash slurry or coal-water-oil slurry, the method for preparing the slurry includes steps S2-S3 or S2-S4. Since the present technical solution is to compare the effect of adding dispersant in stages, step S4 can be a non-essential item.

[0037] The dispersant I is any one of a naphthalene dispersant, an aliphatic dispersant, and a lignin dispersant, or a mixture of any two or three thereof; preferably, naphthalenesulfonic acid formaldehyde copolymer sodium salt (NSF), sodium lignin sulfonate (LS), and sulfonated acetone formaldehyde copolymer (SAF) are selected, and the dispersants in Examples 1-6 are preferred among them.

[0038] The dispersant II is sodium hexametaphosphate or sodium metasilicate and dispersant I (NSF, LS, SAF), among which the dispersants in Examples 1-6 are preferred.

[0039] As a preferred embodiment, the stabilizer is sodium carboxymethyl cellulose (CMC) solution or xanthan gum (TS) solution; the viscosity reducing agent is sodium polyacrylate (PAA), sodium metasilicate or sodium hexametaphosphate.

[0040] The total dispersant is dispersant I and dispersant II, which is essentially the additive that was originally added at one time, divided into two additions, and the two additions are respectively at the mill inlet and the mill outlet.

[0041] A method for preparing slurry by adding additives in a multi-stage method, when preparing oil sludge-coal-water slurry, comprises the following steps:

[0042] S1. Add an emulsifier into a liquid raw material feeding stirring tank to fully emulsify the liquid raw material. The amount of the emulsifier is 0.15-2.0% by weight of the total slurry of the liquid raw material, and then proceed to steps S2-S4.

[0043] S2. At the mill inlet, adding a dispersant I which is beneficial to the dispersion of coal organic matter into the liquid raw material, wherein the amount of the dispersant I is 40-80% of the total dispersant weight;

[0044] S3. At the mill outlet, add dispersant II which is beneficial to the dissociation of clay inorganic substances, and the amount of dispersant II is 60-20% of the total dispersant weight.

[0045] S4. In the stirring barrel at the mill outlet, add a stabilizer that is beneficial to the slurry stability and a viscosity reducer that is beneficial to the viscosity reduction. The amount of stabilizer (on a dry basis) is 20-500ppm of the total slurry of the liquid raw material, and the amount of viscosity reducer (on a dry basis) is 50-100ppm of the total slurry of the liquid raw material.

[0046] When the liquid raw material in step S1 is oil sludge-coal-water slurry, an emulsifier (Tween 80 (TW80) or Tween 60 (TW80)) of 0.15-0.5% of the total mass of the oil sludge is added to a pre-mixing barrel to pre-emulsify the oil sludge, and the emulsified oil sludge, coal, water and water-coal slurry additives (dispersant I, dispersant II, stabilizer and viscosity reducer) are added to a ball mill to prepare an oil sludge-coal-water slurry with good fluidity and stability.

[0047] Embodiment 1:

[0048] A φ3m*13m special ball mill for water-coal slurry is used for continuous water-coal slurry production. The amount of Yancoal coal added is 35.7t / h, the amount of water added is 11.96t / h, 272kg / h of water-coal slurry additive (25wt% NSF:LS=3:7 mixture solution) is added to the feed end of the mill, 408kg / h of water-coal slurry additive (25wt% NSF:LS=7:3 mixture solution) is added to the discharge section of the mill, and samples are taken to measure the concentration, viscosity, particle size and stability of the water-coal slurry.

[0049] Example 2

[0050] Continuous water-coal slurry production is carried out on a φ3.5m*5m special rod mill for water-coal slurry. The amount of Shenhua coal added is 55t / h, the amount of water added is 14.81t / h, 272kg / h of water-coal slurry additive (25wt% LS:SAF=8:2 mixture solution) is added to the feed end of the mill, 405kg / h of water-coal slurry additive (25wt% SAF:LS:sodium hexametaphosphate=80:15:5 mixture solution) is added to the discharge section of the mill, and samples are taken to measure the concentration, viscosity, particle size and stability of the water-coal slurry.

[0051] Example 3

[0052] Continuous water-coal slurry production is carried out on a φ3.5m*5m water-coal slurry special rod mill. The amount of Shenhua coal added is 50t / h, the amount of coal chemical waste slag added is 3t / h, the amount of water added is 13.43t / h, 340kg / h of water-coal slurry additive (25wt% SAF:LS=8:2 mixture solution) is added to the feed end of the mill, 340kg / h of water-coal slurry additive (25wt% SAF:LS: sodium metasilicate=50:45:5 mixture solution) is added to the discharge section of the mill, and samples are taken to determine the concentration, viscosity, particle size and stability of the water-coal slurry.

[0053] Example 4

[0054] In a φ4m*9m mixing barrel, add 50t of oil sludge, add 100kg of emulsifier (TW60) to the oil sludge, stir for 3h, add 5t / h to a φ3m*13m water-coal slurry special ball mill, and carry out continuous oil sludge-coal-water slurry production. The amount of Yancoal coal added is 35.7t / h, the amount of water added is 11.96t / h, 340kg / h of water-coal slurry additive (25wt% NSF:LS=3:7 mixture solution) is added to the feed end of the mill, 340kg / h of water-coal slurry additive (25wt% SAF:LS=7:3 mixture solution) is added to the discharge section of the mill, and samples are taken to determine the concentration, viscosity, particle size and stability of the water-coal slurry.

[0055] Example 5

[0056] A φ3m*13m special ball mill for water-coal slurry is used for continuous water-coal coke slurry production. The amount of petroleum coke added is 18 t / h, the amount of Yancoal coal added is 19.2 t / h, the amount of water added is 13.5 t / h, 300 kg / h of water-coal slurry additive (25wt% NSF:LS=3:7 mixture solution) is added to the feed end of the mill, 200 kg / h of water-coal slurry additive (25wt% NSF:LS:CMC=7:2.997:0.003 mixture solution) is added to the discharge section of the mill, and samples are taken to determine the concentration, viscosity, particle size and stability of the water-coal slurry.

[0057] Example 6

[0058] A φ3m*13m special ball mill for water-coal slurry is used for continuous water-coal coke slurry production. The amount of petroleum coke added is 18 t / h, the amount of Yancoal coal added is 19.2 t / h, the amount of water added is 5.1 t / h, 400 kg / h of water-coal slurry additive (25wt% NSF:LS=3:7 mixture solution) is added to the feed end of the mill, and 500 kg / h of water-coal slurry additive (25wt% NSF:LS:TS=7:2.99:0.01 mixture solution) is added to the discharge section of the mill. Samples are taken to measure the concentration, viscosity, particle size and stability of the water-coal slurry.

[0059] GB-T 188856.5-2008 was used to evaluate the slurry stability, and GB-T 18856.4-2008 was used to measure the slurry viscosity. Under the same mill and the same feed amount, the slurries were prepared by the traditional additive one-time feeding method for comparison, and the slurry properties were measured by the same method.

[0060] Table 1 Properties of water-coal slurry, water-coal-coke slurry, water-coal-ash slurry and coal-water-oil slurry prepared by different additive addition methods

[0061]

[0062] In the table: the addition ratio of feed additive (%) + the addition ratio of discharge additive (%) is 100% (weight ratio), wherein: feed additive refers to the additive added at the inlet of the mill, and discharge additive refers to the additive added at the outlet of the mill.

[0063] In each group of comparative tests in the above table, the total amount of dispersant, stabilizer and / or viscosity reducer added is the same, the only difference is whether it is added all at once or in stages, and the specific operation of the staged addition is shown in Examples 1-6; it can be seen from the above table that after the staged addition, the slurry stability is stronger.

[0064] The present invention is based on the study of the slurry grinding process. It is a method of adding different types and amounts of additives to the stirring tank, the mill feed section and the mill outlet before the raw materials enter the mill. The multi-stage method of adding additives can improve the dispersion state of particles, optimize the particle size distribution, rheological properties, constant viscosity concentration and stability of the slurry during the slurry preparation process; and can be applied to the mixed slurrying of various raw materials; it is easy to operate, low in cost, good in effect, and has a high value of promotion and application.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing slurry by adding additives in a multi-stage process, characterized in that: The following steps are involved: S2. At the mill inlet, adding a dispersant I which is beneficial to the dispersion of coal organic matter into the liquid raw material, wherein the amount of the dispersant I is 40-80% of the total dispersant weight; S3. At the mill outlet, add dispersant II which is beneficial to the dissociation of clay inorganic substances, and the amount of dispersant II is 60-20% of the total dispersant weight.

2. The method for preparing slurry by adding additives in multiple stages according to claim 1, characterized in that: S4. In the mixing barrel at the mill outlet, add a stabilizer that is beneficial to the slurry stability and a viscosity reducer that is beneficial to the viscosity reduction. The amount of the stabilizer is 20-500ppm of the total amount of the liquid raw material slurry on a dry basis, and the amount of the viscosity reducer is 50-100ppm of the total amount of the liquid raw material slurry on a dry basis.

3. The method for preparing slurry by adding additives in multiple stages according to claim 2, characterized in that: The liquid raw material is oily wastewater, and the liquid raw material is water-coal slurry, water-coal-coke slurry, water-coal slag slurry, coal-water-oil slurry or oil sludge-coal-water slurry.

4. The method for preparing slurry by adding additives in multiple stages according to claim 3, characterized in that: When the liquid raw material is water-coal slurry, water-coal-coke slurry, water-coal-ash slurry or coal-water-oil slurry, the method for preparing the slurry includes steps S2-S3 or S2-S4.

5. The method for preparing slurry by adding additives in multiple stages according to claim 3, characterized in that: When the liquid raw material is oil sludge-coal-water slurry, before step S2, the following steps are also included: S1. Add an emulsifier into the liquid raw material feeding stirring tank to fully emulsify the liquid raw material. The amount of the emulsifier is 0.15-2.0% by weight of the total slurry of the liquid raw material, and then proceed to step S2-S3 or S2-S4.

6. The method for preparing slurry by adding additives in multiple stages according to claim 5, characterized in that: When the liquid raw material in step S1 is oil sludge-coal-water slurry, an emulsifier of 0.15-2.0% of the total mass of the oil sludge is added to the pre-mixing barrel.

7. The method for preparing slurry by adding additives in multiple stages according to claim 1, characterized in that: The dispersant I is any one of a naphthalene dispersant, an aliphatic dispersant, and a lignin dispersant, or a mixture of any two or three thereof; The dispersant II is sodium hexametaphosphate or sodium metasilicate and dispersant I.

8. The method for preparing slurry by adding additives in multiple stages according to claim 1, characterized in that: The stabilizer is sodium carboxymethyl cellulose solution or xanthan gum solution; The viscosity reducing agent is sodium polyacrylate, sodium metasilicate or sodium hexametaphosphate.

9. The method for preparing slurry by adding additives in multiple stages according to claim 1, characterized in that: The mill outlet is on a vibrating screen or an outlet drum screen.

10. A method for preparing slurry by adding additives in multiple stages according to claim 5 or 6, characterized in that: The emulsifier is Tween or polyoxyethylene ether.

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