A process for purifying and electrolyzing hydrogen coupling of mudified high-ash coal slurry water

Abstract

The application provides a slurry high-ash coal slurry water electroflocculation purification and electrolysis hydrogen production coupling process, which comprises the following steps: a grading process, in which coal slurry water is subjected to grading treatment to obtain first mixed coal slurry material and second mixed coal slurry material, wherein the particle size of the first mixed coal slurry material is smaller than that of the second mixed coal slurry material, and the ash content of the particles in the first mixed coal slurry material is greater than that of the particles in the second mixed coal slurry material; a flotation process, in which the second mixed coal slurry material is subjected to flotation treatment to obtain clean coal material and tail coal material; and an electrolysis process, in which the first mixed coal slurry material and / or the tail coal material is introduced into an electrolytic cell containing electrolyte for electrolysis treatment, and hydrogen generated by the electrolysis treatment is collected from the electrolytic cell to the outside of the electrolytic cell. The process can improve the treatment efficiency and reduce the treatment cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal slime water treatment, and particularly relates to a coupling process of electroflocculation purification and electrolytic hydrogen production for high-ash sliming coal slime water. BACKGROUND

[0002] Coal slime water is an industrial wastewater generated in a coal preparation process and a processing process, which is mixed with a large amount of coal powder and soil. In recent years, with the deterioration of coal quality and the continuous improvement of coal mining mechanization, the gangue content in raw coal is relatively high, and the gangue is prone to sliming, which further causes the coal slime water generated in the coal preparation process to be high-sliming and difficult-to-settle coal slime water, thereby greatly affecting the subsequent treatment of the coal slime water.

[0003] In the related art, the treatment efficiency of the sliming coal slime water containing fine coal is low, and the treatment cost is high. SUMMARY

[0004] In view of the technical problems of low treatment efficiency and high energy consumption of the coal slime water, and high treatment cost, the present application provides a coupling process of electroflocculation purification and electrolytic hydrogen production for high-ash sliming coal slime water, which can improve the treatment efficiency and reduce the treatment cost.

[0005] The present application provides a coupling process of electroflocculation purification and electrolytic hydrogen production for high-ash sliming coal slime water, comprising:

[0006] a classification process for classifying the coal slime water to obtain a first mixed coal slime material and a second mixed coal slime material, wherein the particle size of the first mixed coal slime material is smaller than that of the second mixed coal slime material, and the ash content of the particles in the first mixed coal slime material is greater than that of the second mixed coal slime material;

[0007] a flotation process for floating the second mixed coal slime material to obtain a clean coal material and a tail coal material;

[0008] an electrolysis process for passing the first mixed coal slime material and / or the tail coal material into an electrolytic tank containing an electrolyte for electrolysis treatment, so as to precipitate the first mixed coal slime material at the anode and collect hydrogen gas generated at the cathode from the electrolytic tank to the outside of the electrolytic tank.

[0009] According to any one of the foregoing embodiments of the first aspect of the present application, the classification process comprises:

[0010] The coal slurry is sequentially subjected to first, second and third classification treatments, wherein the first classification treatment respectively produces a first overflow material and a first underflow material, and the particle size in the first overflow material is smaller than that in the first underflow material, and the ash content of the particles in the first overflow material is greater than that in the first underflow material; the second classification treatment respectively produces a second overflow material and a second underflow material, and the particle size in the second overflow material is smaller than that in the second underflow material, and the ash content of the particles in the second overflow material is greater than that in the second underflow material; and the third classification treatment respectively produces a third overflow material and a third underflow material, and the particle size in the third overflow material is smaller than that in the third underflow material, and the ash content of the particles in the third overflow material is greater than that in the third underflow material.

[0011] The first overflow material, the second overflow material and the third overflow material are mixed to obtain the first mixed coal slurry material, and the first underflow material, the second underflow material and the third underflow material are mixed to obtain the second mixed coal slurry material.

[0012] According to any of the foregoing embodiments of the first aspect of the application, in the first classification treatment, a cyclone with a diameter of 150 mm is used.

[0013] In the second classification treatment, a cyclone with a diameter of 75 mm is used.

[0014] In the third classification treatment, a cyclone with a diameter of 50 mm is used.

[0015] According to any of the foregoing embodiments of the first aspect of the application, if the ash content of the particles in the first mixed coal slurry material is greater than or equal to 70%, the first mixed coal slurry material does not need to be subjected to electrolytic treatment.

[0016] According to any of the foregoing embodiments of the first aspect of the application, in the electrolysis process, the pH of the electrolytic treatment is 4-8, the time of the electrolytic treatment is 4 min-10 min, and the ratio of the current density to the voltage of the electrolytic treatment is (1-4):1.

[0017] According to any of the foregoing embodiments of the first aspect of the application, the current density of the electrolytic treatment is 500 A / m 2 The voltage of the electrolytic treatment is 1 V-9 V.

[0018] According to any of the foregoing embodiments of the first aspect of the application, the electrolyte comprises a sodium salt electrolyte.

[0019] According to any of the preceding embodiments of the first aspect of the present application, the sodium salt electrolyte comprises a mixture of one or more of sodium chloride, sodium sulfate and sodium phosphate.

[0020] The second aspect of the present application provides a slurrification high-ash coal slurry water electroflocculation purification and electrolysis hydrogen production coupling system, comprising:

[0021] a grading unit configured to grade the coal slurry water to obtain a first mixed coal slurry material and a second mixed coal slurry material, wherein the particle size of the first mixed coal slurry material is smaller than that of the second mixed coal slurry material, and the ash content of the particles in the first mixed coal slurry material is greater than that of the particles in the second mixed coal slurry material;

[0022] a flotation unit configured to float the second mixed coal slurry material to obtain a clean coal material and a tail coal material;

[0023] an electrolysis unit configured to pass the first mixed coal slurry material and / or the tail coal material into an electrolytic cell containing an electrolyte to perform electrolysis treatment, to precipitate the first mixed coal slurry material at an anode and to collect hydrogen gas generated at a cathode from the electrolytic cell to the outside of the electrolytic cell.

[0024] According to any of the preceding embodiments of the second aspect of the present application, the electrolysis unit comprises:

[0025] an anode, a material of the anode comprising an aluminum-zinc-indium alloy;

[0026] a cathode;

[0027] an electrolyte membrane disposed between the anode and the cathode, the electrolyte membrane comprising a proton exchange membrane, and the proton exchange membrane having a fluorocarbon main chain and a sulfonic acid side chain;

[0028] and a voltage applicator connected to the anode and the cathode to apply a voltage between the anode and the cathode.

[0029] Compared with the prior art, the technical solution provided by the present application has the following beneficial effects:

[0030] The first mixed slime material and the second mixed slime material can be obtained through the classification process, wherein the particle size of the first mixed slime material is smaller than that of the second mixed slime material, and the ash content of the particles in the first mixed slime material is greater than that of the particles in the second mixed slime material; the second mixed slime material is subjected to the flotation process to obtain the clean coal material and the tail coal material; the first mixed slime material and / or the tail coal material is introduced into the electrolytic tank containing the electrolyte to be subjected to the electrolysis process, so as to precipitate the first mixed slime material at the anode and collect the hydrogen gas generated at the cathode from the electrolytic tank to the outside of the electrolytic tank. The classification process can classify the slime water material to obtain the first mixed slime material and the second mixed slime material, the second mixed slime material can be directly subjected to the flotation process to obtain the clean coal material and the tail coal material, and then the first mixed slime material and / or the tail coal material is subjected to the electrolysis process. It is found through experiments that in the electrolysis process, the first mixed slime material with smaller particle size is easy to settle, and the ash content of the settled particles is reduced, thereby improving the processing efficiency, and the particles with smaller particle size can be quickly settled without adding additives, thereby reducing the processing cost. In addition, the electrolysis process can obtain high-value hydrogen gas, thereby further reducing the processing cost of the slime water.

[0031] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the present application, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0033] Figure 1 A flow chart of a slime water purification and hydrogen production coupling process provided by some embodiments of the present application is shown. DETAILED DESCRIPTION

[0034] The ranges disclosed herein are intended to be "open" ranges, i.e., the upper and lower limits of the range are not included. The ranges can be "closed" ranges, i.e., the upper and lower limits of the range are included. The ranges can be any combination of open and closed ranges. For example, if a range of 60-120 and a range of 80-110 are listed, it is understood that a range of 60-110 and a range of 80-120 are also contemplated. Furthermore, if a minimum range value of 1 and 2 are listed, and if a maximum range value of 3, 4, and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise indicated, a numerical range "a-b" means a range of any combination of the numbers a and b, in which a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is merely a shorthand for listing all of those numbers. Also, when a parameter is stated to be an integer > 2, it is equivalent to state that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0035] Unless otherwise indicated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0036] Unless otherwise indicated, all technical features and optional technical features of the present application can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present application.

[0037] Unless otherwise indicated, all steps of the present application can be performed in sequence or randomly, and preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method also comprises step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0038] Unless otherwise indicated, the "includes" and "contains" mentioned in the present application mean open-ended and can also be closed-ended. For example, the "includes" and "contains" can mean that other components not listed can also be included or contained, or only the listed components can be included or contained.

[0039] The term "or" is inclusive in this application, unless otherwise indicated. So for example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following satisfy the condition "A or B": A is true (or present) and B is false (or not present); A is false (or not present) and B is true (or present); or both A and B are true (or present).

[0040] The terms used in this application, unless otherwise indicated, have their ordinary meanings as understood by one of ordinary skill in the art.

[0041] Unless otherwise indicated, the values of the parameters mentioned in this application can be measured by various test methods commonly used in the art, for example, according to the test methods given in the embodiments of this application.

[0042] See Figure 1 The first aspect of the present application provides a process for purifying and producing hydrogen by coupling electro-flocculation of high-ash slurry and electrolysis, comprising:

[0043] S100, a grading process, grading the coal slurry to obtain a first mixed coal slurry and a second mixed coal slurry, wherein the particle size of the first mixed coal slurry is smaller than that of the second mixed coal slurry, and the ash content of the particles in the first mixed coal slurry is greater than that of the second mixed coal slurry;

[0044] S200, a flotation process, floating the second mixed coal slurry to obtain clean coal material and tail coal material;

[0045] S300, an electrolysis process, passing the first mixed coal slurry and / or the tail coal material into an electrolytic cell containing electrolyte for electrolysis treatment, to precipitate the first mixed coal slurry at the anode and collect the hydrogen gas generated at the cathode from the electrolytic cell to the outside of the electrolytic cell.

[0046] The first mixed slime material and the second mixed slime material can be obtained through the grading process, wherein the particle size of the first mixed slime material is smaller than that of the second mixed slime material, and the ash content of the particles in the first mixed slime material is greater than that of the particles in the second mixed slime material; the second mixed slime material is subjected to the flotation process to obtain the clean coal material and the tail coal material; the first mixed slime material and / or the tail coal material is subjected to the electrolysis process to be introduced into the electrolytic tank containing the electrolyte to be subjected to the electrolysis treatment, so that the first mixed slime material at the anode is precipitated and the hydrogen gas generated at the cathode is collected from the electrolytic tank to the outside of the electrolytic tank. The grading process can grade the slime water material to obtain the first mixed slime material and the second mixed slime material, the second mixed slime material can be directly subjected to the flotation process to obtain the clean coal material and the tail coal material, and then the first mixed slime material and / or the tail coal material is subjected to the electrolysis treatment. It is found through experiments that in the electrolysis treatment, the first mixed slime material with smaller particle size is easy to settle, the ash content of the settled particles is reduced, and the treatment efficiency is improved. Moreover, the smaller particles can be quickly settled without adding additives, thereby reducing the treatment cost. In addition, the electrolysis treatment can obtain high-value hydrogen gas, thereby further reducing the treatment cost of the slime water.

[0047] In this paper, the ash content refers to the inorganic matter obtained by calcining the remaining residue after the coal sample is burned under specified conditions, expressed in percentage by mass.

[0048] In the embodiment of the present application, the average ash content of the slime water is about 47.84%, wherein the proportion of particles with a particle size less than 0.045mm is 60.4%, and the ash content thereof is 60.4%; the proportions of particles with a particle size of 0.074-0.045mm and 0.25-0.125mm are 11.3% and 10.0% respectively, and the ash contents thereof are 39.5% and 25.3% respectively; the proportion of particles with a particle size greater than 0.045mm is 38.6%, and the ash content thereof is 27.88%.

[0049] In some optional embodiments of the present application, the grading process comprises:

[0050] The coal slurry is sequentially subjected to first-stage classification treatment, second-stage classification treatment and third-stage classification treatment, wherein the first-stage classification treatment respectively obtains first overflow material and first underflow material, and the particle size in the first overflow material is smaller than the particle size in the first underflow material, and the particle ash content in the first overflow material is greater than the particle ash content in the first underflow material; the second-stage classification treatment respectively obtains second overflow material and second underflow material, and the particle size in the second overflow material is smaller than the particle size in the second underflow material, and the particle ash content in the second overflow material is greater than the particle ash content in the second underflow material; the third-stage classification treatment respectively obtains third overflow material and third underflow material, and the particle size in the third overflow material is smaller than the particle size in the third underflow material, and the particle ash content in the third overflow material is greater than the particle ash content in the third underflow material.

[0051] The first overflow material, the second overflow material and the third overflow material are mixed to obtain first mixed coal slurry material, and the first underflow material, the second underflow material and the third underflow material are mixed to obtain second mixed coal slurry material.

[0052] In the above embodiments, through the three-stage classification treatment, the first mixed coal slurry with small particle size and high ash content and the second mixed coal slurry with large particle size and low ash content can be separated, so that different treatment methods can be used for the mixed coal slurry with different particle sizes and ash contents to obtain the required coal, wherein the second mixed coal slurry is subjected to flotation treatment, and the first mixed coal slurry is subjected to electrolysis treatment, thereby realizing efficient treatment of the coal slurry.

[0053] In some optional embodiments of the present application, in the first-stage classification treatment, a cyclone with a diameter of 150 mm is used; in the second-stage classification treatment, a cyclone with a diameter of 75 mm is used; and in the third-stage classification treatment, a cyclone with a diameter of 50 mm is used.

[0054] In the above embodiments, a conical one-heavy three-stage cyclone group with a treatment capacity of 50 m 3 / h is used, and the model is CMC-Φ150-4×Φ75-4×Φ50, that is, the cyclone group is composed of a main cyclone with a diameter of 150 mm, 4 secondary cyclones (with a diameter of 75 mm) and 4 tertiary cyclones (with a diameter of 50 mm) connected in parallel through a conical generator, which performs secondary classification on the overflow of the 150 mm main cyclone, ensures that the overflow does not run coarse, realizes removal of the overflow of the ultra-fine particle level, and performs desliming pretreatment on the flotation feed.

[0055] In some optional embodiments of the present application, if the particle ash content in the first mixed coal slurry material is greater than or equal to 70%, the first mixed coal slurry material does not need to be subjected to electrolysis treatment.

[0056] In some optional embodiments of the present application, the pH of the electrolysis process is 4-8. In this pH range, a large amount of Al 13 The structural core of Al 13 is tetrahedral AlO4, and the periphery is 12 octahedral Al(OH)2. This structure is called Keggin cage structure, and Al 13 Due to the AlO4 core and the different polymer structures of the peripheral Al coordination number, it is inert in the further hydrolysis and chemical equilibrium reaction and becomes a stable compound. When the pH is 4-8, it helps to maintain the stability of the Al 13 morphology and structure, and further enables its strong positive charge and adsorption aggregation capacity, thereby exhibiting superior coagulation-flocculation effect.

[0057] In the embodiments of the present application, the morphology of aluminum can be characterized by methods well known in the art, such as Al-Ferron hour-by-hour complexation colorimetry, 27Al nuclear magnetic resonance (27Al-NMR) method, and electrospray mass spectrometry (ESI-MS).

[0058] In some optional embodiments of the present application, the electrolysis process is performed for 4-10 minutes. When the electrolysis process is performed for 4-10 minutes, a higher concentration of Al 13 can be obtained, thereby helping the small-sized materials to settle.

[0059] In some optional embodiments of the present application, the ratio of the current density to the voltage of the electrolysis process is (1-4):1. When the ratio of the current density to the voltage is in the above range, the energy consumption can be reduced and the reaction rate can be increased.

[0060] In some optional embodiments of the present application, the current density of the electrolysis process is 500 A / m 2 The voltage of the electrolysis process is 1-9 V.

[0061] In some optional embodiments of the present application, the electrolyte includes a sodium salt electrolyte. The sodium salt electrolyte can help to increase the conductivity of the electrolyte to reduce the energy consumption.

[0062] In some optional embodiments of the present application, the sodium salt electrolyte includes a mixture of one or more of sodium chloride, sodium sulfate, and sodium phosphate. The above electrolyte can improve the conductivity of the electrolyte and reduce the energy consumption. Among them, the addition of Cl ions can eliminate the adverse effects of carbonate and sulfate on the electrocoagulation process.

[0063] In some optional embodiments of the present application, the electrolysis treatment is carried out under stirring, wherein the stirring rate is 300 rpm / min to 1000 rpm / min. The stirring can delay the passivation of the anode surface, thereby helping to improve the reaction rate.

[0064] The second aspect of the present application provides a slurry water purification and hydrogen production coupling system for high-ash slurry, comprising:

[0065] a grading unit configured to grade the slurry water to obtain a first mixed slurry material and a second mixed slurry material, wherein the particle size of the first mixed slurry material is smaller than that of the second mixed slurry material, and the ash content of the particles in the first mixed slurry material is greater than that of the second mixed slurry material;

[0066] a flotation unit configured to float the second mixed slurry material to obtain a clean coal material and a tail coal material;

[0067] an electrolysis unit configured to pass the first mixed slurry material and / or the tail coal material into an electrolytic cell containing an electrolyte for electrolysis treatment, to precipitate the first mixed slurry material at the anode and collect the hydrogen gas generated at the cathode from the electrolytic cell to the outside of the electrolytic cell.

[0068] In some optional embodiments of the present application, the electrolysis unit comprises:

[0069] an anode, the material of the anode comprising aluminum or aluminum-zinc-indium alloy;

[0070] a cathode;

[0071] an electrolyte membrane arranged between the anode and the cathode, the electrolyte membrane comprising a proton exchange membrane, and the proton exchange membrane having a fluorocarbon main chain and a sulfonic acid side chain;

[0072] and a voltage applicator connected to the anode and the cathode to apply a voltage between the anode and the cathode.

[0073] In the above embodiments, the material of the anode comprises aluminum-zinc-indium alloy, which can reduce the occurrence of passivation on the surface of the anode, thereby helping to improve the reaction rate of electrolysis. In addition, the reaction voltage required for the dissolution of the above-mentioned aluminum alloy is low, and the energy consumption is also low, thereby further reducing the processing cost of the slurry water.

[0074] The proton exchange membrane has two types of hydrophobic main chain and hydrophilic side chain, the fluorocarbon main chain ensures good ion conductivity, and the sulfonic acid side chain ensures the selective permeability of the membrane. The chain crosslinking structure makes the chemical properties and structure of the membrane stable.

[0075] In some optional embodiments of the present invention, the distance between the anode and the cathode is 1 cm to 5 cm. When the electrode spacing is within the above range, the conductivity can be improved, thereby achieving the purpose of improving the reaction rate.

[0076] In some alternative embodiments of the present invention, the cathode material may include aluminum or graphite.

[0077] The following examples use coal slurry water produced in the Burtai coal preparation plant as the wastewater to be treated for detailed explanation.

[0078] Coal sample grading test:

[0079] The coal samples were graded according to GB / T 477-2008 "Coal Grading Test Methods". The test results are shown in Table 1.

[0080] Table 1. Particle size distribution results of coal after grading

[0081]

[0082] Grading process:

[0083] A cone-type multi-stage hydrocyclone group is adopted. This hydrocyclone group consists of a 150mm diameter main hydrocyclone, which is connected in parallel with four secondary (75mm diameter) hydrocyclones and four tertiary (50mm diameter) hydrocyclones through a cone generator. The overflow of the 150mm main hydrocyclone is subjected to secondary classification, thereby realizing the ultrafine particle classification of 7.33t of high-ash coal slurry water. The underflow of hydrocyclones has a low ash content and is used as flotation feed for flotation treatment to ensure the quality and yield of flotation clean coal. At the same time, taking advantage of the good treatment effect of electrolysis on wastewater with high fine particle content, the overflow of hydrocyclones (i.e., the first mixed coal slurry material) and flotation tailings are electrolyzed.

[0084] Table 2. Experimental results of high-ash coal slurry water classified by hydrocyclone.

[0085]

[0086] As shown in Table 2, the ash content of the mixed overflow was 61.44%, and the ash content of the first overflow material (the overflow of the Φ150 main hydrocyclone) was 55.34%. The coarse particles in the overflow were recovered through secondary classification by the secondary and tertiary hydrocyclones, and the ash content of the overflow was further improved.

[0087] The particle size distribution of the overflow after fractionation in a cone-shaped multistage hydrocyclone was analyzed using a BT-2003 laser particle size analyzer.

[0088] Table 3. Particle size distribution results

[0089]

[0090]

[0091]

[0092]

[0093] The analysis table shows that:

[0094] (1) The yield of less than 2 μm in overflow is 25%;

[0095] (2) The yield of less than 5 μm in overflow is 50%;

[0096] (3) The yield of less than 10 μm (1250 mesh) in overflow is 70%;

[0097] (4) The yield of less than 35 μm (325 mesh) in overflow is greater than 90.0%;

[0098] (5) The yield of less than 75 μm (200 mesh) in overflow is greater than 99.0%.

[0099] Flotation process:

[0100] The underflow obtained in the classification process is sent to a jet microbubble flotation machine with a treatment capacity of 100 m 3 / h for flotation treatment. Kerosene is used as a collector at a dosage of 1 kg / t, and No. 2 oil is used as a frother at a dosage of 1 kg / t. The test results are shown in Table 4.

[0101] Table 4 Test results after flotation

[0102]

[0103]

[0104] Electrolysis process:

[0105] The material of the anode is aluminum-zinc-indium alloy, and the electrolyte is prepared according to the ratio of NaCl (0.05 M) to NaHCO3 (0.5 mM). A 1 L glass beaker is used as an electrolytic cell, an intelligent constant temperature magnetic stirrer (ZNCL-S) is used to stir and regulate the temperature of the electrolyte, a direct current power supply is used for electrolysis, an electrochemical workstation (Donghua DH7002) is used, the size of the anode and cathode (aluminum plate with a purity of 99.99%) is 2 cm x 2 cm x 0.2 cm, and a perfluorosulfonic acid proton exchange membrane is used.

[0106] Before each experiment, the surface of the anode and cathode plates was cleaned of impurities using sandpaper, and immersed in 1.3 M HC1 for 10 min, and finally washed with deionized water. Before each experiment, 1 L of electrolyte was added to the beaker, the magnetic stirrer was turned on, and the rotation speed was adjusted to 300 rpm / min, 0.01 M NaOH was added to adjust the initial pH of the solution to 7, and electrolysis was carried out according to the experimental conditions in Table 5, and the thickness of the coal slime was measured after the electrolysis was completed according to the preset settling time of each group. The thickness of the coal slime can be measured by an ultrasonic thickness gauge, i.e. the thickness of the coal slime at 5-6 points is measured by an ultrasonic thickness gauge, and the average value is calculated, which can be used as the thickness of the coal slime in Table 5.

[0107] The concentration of coal slime in the overflow was 34 g / L, and the ash content was 60%.

[0108] Table 5 Test results obtained by using different voltages and current densities in electrolytic treatment

[0109]

[0110]

[0111] As can be seen from Table 5, the supernatant obtained from the 9 groups of electrolysis experiments is clear and transparent, indicating that the aluminum complex product produced by electrolysis has stronger activity and adsorption performance, and has better coagulation effect on very fine slime.

[0112] Table 6 Test results obtained by using different electrolysis conditions in electrolytic treatment

[0113]

[0114] As can be seen from Table 6, when the pH of electrolytic treatment is 4-8, the electrolytic treatment time is 4 min-10 min, and the ratio of current density to voltage is (1-4): 1, the concentration of Al 13 The concentration of Al is relatively high, which can help the fine coal slime particles to settle quickly.

[0115] Comparative Example

[0116] The difference from the above examples is that the comparative example does not use an electrolysis process, but prepares polyaluminum chloride PAC with a concentration of 2%, and prepares polyacrylamide PAM with a concentration of 0.2%, and carries out a settling experiment with 500 ml of high-ash coal slime water, and the experimental results are as follows:

[0117] Table 7 Results of overflow dosing coagulation experiment

[0118]

[0119] Through adding medicine and electrolytic subsidence experiment to the same batch of water sample, 500ml water sample added 10ml polyaluminum chloride, the supernatant was turbid, which showed that the adding amount of polyaluminum chloride was insufficient, after adding 15ml, the supernatant became translucent, the effect was improved, continue to add 20ml, the supernatant was still translucent, there was no obvious change, and the thickness of coal slime also had no obvious increase, which showed that simply increasing the amount of polyaluminum chloride could not make the extremely fine coal slime water to be clarified; and from the electrolytic treatment in table 5, the supernatant of 9 groups of experiments was clear and transparent, which showed that the aluminum complex product generated by electrolysis had stronger activity and adsorption performance, and had better coagulation effect on extremely fine slime.

[0120] Finally, it should be pointed out that: the above experimental examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing experimental examples, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing experimental examples, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the experimental examples of the present application.

Claims

1. A coupled process for the hydro-flocculation purification and electrolytic hydrogen production of high-ash coal slime, characterized in that, include: The grading process involves classifying the coal slurry water to obtain a first mixed coal slurry material and a second mixed coal slurry material. The particle size of the first mixed coal slurry material is smaller than that of the second mixed coal slurry material, and the particle ash content of the first mixed coal slurry material is greater than that of the second mixed coal slurry material. In the flotation process, the second mixed coal slime material is subjected to flotation treatment to obtain clean coal material and tailings material; In the electrolysis process, the first mixed coal slime material and / or the tailings material are fed into an electrolytic cell containing electrolyte for electrolysis treatment, so as to precipitate the first mixed coal slime material and / or tailings material at the anode and collect the hydrogen gas generated at the cathode from the electrolytic cell to the outside of the electrolytic cell; The grading process includes: The coal slurry is subjected to a first classification treatment, a second classification treatment, and a third classification treatment in sequence. The first classification treatment yields a first overflow material and a first underflow material, with the particle size of the first overflow material being smaller than that of the first underflow material, and the particle ash content of the first overflow material being greater than that of the first underflow material. The second classification treatment yields a second overflow material and a second underflow material, with the particle size of the second overflow material being smaller than that of the second underflow material, and the particle ash content of the second overflow material being greater than that of the second underflow material. The third classification treatment yields a third overflow material and a third underflow material, with the particle size of the third overflow material being smaller than that of the third underflow material, and the particle ash content of the third overflow material being greater than that of the third underflow material. The first overflow material, the second overflow material, and the third overflow material are mixed to obtain the first mixed coal slime material, and the first underflow material, the second underflow material, and the third underflow material are mixed to obtain the second mixed coal slime material.

2. The coupled process of hydro-flocculation purification and electrolytic hydrogen production of muddy high-ash coal slime according to claim 1, characterized in that, In the first grading process, a hydrocyclone with a diameter of 150 mm was used; In the second grading process, a hydrocyclone with a diameter of 75 mm is used; In the third grading process, a hydrocyclone with a diameter of 50 mm was used.

3. The coupled process of hydro-flocculation purification and electrolytic hydrogen production of muddy high-ash coal slime according to claim 2, characterized in that, If the particulate ash content in the first mixed coal slime is greater than or equal to 70%, then the first mixed coal slime does not need to be electrolyzed.

4. The coupled process of hydro-flocculation purification and electrolytic hydrogen production of muddy high-ash coal slime according to claim 1, characterized in that, In the electrolysis process, the pH of the electrolysis treatment is 4-8, the electrolysis treatment time is 4 min-10 min, and the ratio of the current density to the voltage of the electrolysis treatment is (1-4):

1.

5. The coupled process of hydro-flocculation purification and electrolytic hydrogen production of mudded high-ash coal slime according to claim 4, characterized in that, The current density of the electrolytic treatment is 500 A / m. 2 The voltage for the electrolytic treatment described below is 1V-9V.

6. The coupled process of hydro-coagulation purification and electrolytic hydrogen production of high-ash coal slime according to claim 1, characterized in that, The electrolyte includes a sodium salt electrolyte.

7. The coupled process of hydro-flocculation purification and electrolytic hydrogen production of high-ash coal slime according to claim 6, characterized in that, The sodium salt electrolyte includes a mixture of one or more of sodium chloride, sodium sulfate, and sodium phosphate.

8. A coupled system for hydro-coagulation purification and electrolytic hydrogen production of high-ash coal slime as described in any one of claims 1-7, characterized in that, include: A grading unit is used to grade the coal slurry water to obtain a first mixed coal slurry material and a second mixed coal slurry material, wherein the particle size of the first mixed coal slurry material is smaller than the particle size of the second mixed coal slurry material, and the particle ash content of the first mixed coal slurry material is greater than the particle ash content of the second mixed coal slurry material. The flotation unit is used to perform flotation treatment on the second mixed coal slime material to obtain clean coal material and tailings material; An electrolysis unit is used to pass the first mixed coal slime material and / or the tailings material into an electrolytic cell containing an electrolyte for electrolytic treatment, so as to precipitate the first mixed coal slime material at the anode and collect the hydrogen gas generated at the cathode from the electrolytic cell to the outside of the electrolytic cell.

9. The coupled system for hydro-coagulation purification and electrolytic hydrogen production of high-ash coal slime according to claim 8, characterized in that, The electrolysis unit includes: The anode, wherein the material of the anode includes aluminum or an aluminum-zinc-indium alloy; cathode; An electrolyte membrane is disposed between the anode and the cathode, the electrolyte membrane comprising a proton exchange membrane having a fluorocarbon backbone and sulfonic acid side chains; And a voltage applicator, connected to the anode and the cathode, to apply a voltage between the anode and the cathode.

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