阅读说明：本技术 一种快速匹配煤种制备高性能水煤浆的方法 (Method for preparing high-performance coal water slurry by quickly matching coal types ) 是由 褚睿智 叶泽甫 孟献梁 朱竹军 吴国光 李晓 江晓凤 李雨龙 俞时 宋上 樊茂洲 于 2021-01-12 设计创作，主要内容包括：本发明公开了一种快速匹配煤种制备高性能水煤浆的方法,先测量不同种类的添加剂在一定浓度下的表面张力,根据与水的表面张力的差值分为ABC三个等级；再测量不同添加剂溶液在煤表面的接触角,根据30秒内溶液在煤表面的接触角减小值大小分为ABC三个等级；取适量震荡后均匀分散煤粒的溶液,测量pH值为7时煤粒表面的Zeta值,根据与原煤表面的电位绝对值的差值分为ABC三个等级,根据前面的等级进行排序,选择选取前三个等级的添加剂进行制浆实验,对浆体进行定粘浓度S和析水率D测量,再次进行等级排序。本发明制定了一系列的参数标准,可判定不同添加剂的等级确定煤与添加剂的适应性,缩减判定实验流程,提高添加剂与煤之间的匹配性和匹配效率。(The invention discloses a method for preparing high-performance coal water slurry by quickly matching coal types, which comprises the steps of firstly measuring the surface tension of different additives under certain concentration, and classifying the additives into ABC three grades according to the difference value of the surface tension of the additives and the surface tension of water; measuring contact angles of different additive solutions on the surface of the coal, and classifying the contact angles into ABC three grades according to the reduction values of the contact angles of the solutions on the surface of the coal within 30 seconds; taking a proper amount of solution which uniformly disperses the coal particles after oscillation, measuring the Zeta value of the surface of the coal particles when the pH value is 7, dividing the solution into three grades ABC according to the difference value of the potential absolute value of the surface of the raw coal, sorting according to the previous grades, selecting additives of the first three grades to perform a pulping experiment, measuring the fixed viscosity concentration S and the water separation rate D of the slurry, and sorting again. The invention sets a series of parameter standards, can judge the grades of different additives to determine the adaptability of the coal and the additives, reduces the judging experimental process and improves the matching performance and the matching efficiency between the additives and the coal.)

1. A method for preparing high-performance coal water slurry by quickly matching coal types is characterized by comprising the following steps:

the method comprises the following steps: respectively preparing different additives into solutions with certain concentration, measuring the surface tension of different solutions at room temperature, subtracting the surface tension of the solutions from the surface tension of water at room temperature to obtain a difference value M, and ranking according to the following standard: a: m is more than 20 mN/M; b: 10< M <20 mN/M; c: m <10 mN/M;

step two: and (3) measuring the contact angle of the different additive solutions prepared in the step one on the surface of the coal, and measuring the contact angle reduction value N of the solutions on the surface of the coal within 30 seconds, wherein the solutions are graded according to the following standard: a: n >20 °; b: 10 ° < N <20 °; c: n <10 °;

step three: respectively placing a proper amount of coal powder into a sample solution with a certain volume prepared in the first step, vibrating and adsorbing at room temperature, taking a proper amount of solution which uniformly disperses coal particles after vibration, measuring the Zeta value of the surface of the coal particles when the pH value is 7, and recording the absolute value of the potential of the surface of raw coal subtracted from the absolute value of the measured value as Z, wherein the levels are arranged according to the following standards: a: z is > 35; b: 15< Z < 35; c: z < 15;

step four: sorting according to grades of different additives in the first step to the third step: first-stage: AAA; and (2) second stage: AAB, ABA, BAA; third-stage: ABB, BAB, BBA, AAC, ACA, CAA,; and (4) fourth stage: BBB and below BBB;

step five: according to the grade determined in the fourth step, the additives in the first three grades are selected to be respectively subjected to a dry powder pulping experiment, the slurry is subjected to measurement of the viscosity concentration S and the water separation rate D, and the two performance grades are respectively sequenced: fixed viscosity concentration S: a: s is more than 65%; b: 61% < S < 65%; c: s < 61%; water separation rate D: a: d < 3%; b: 3% < D < 5%; c: d is greater than 5%;

step six: and selecting the additives required by the process according to the test result of the step five.

2. The method for preparing high-performance coal-water slurry by quickly matching coal types according to claim 1, wherein in the step one, the surface tension is measured by a pendant drop method.

3. The method for preparing high-performance coal-water slurry by rapidly matching coal types according to claim 1, wherein in the step one, the additive is at least three of naphthalene-based, lignin-based, aliphatic-based, humic acid-based and melamine-based coal-water slurry additives.

4. The method for preparing high-performance coal water slurry by quickly matching coal types according to claim 1, wherein in the third step, the particle size of the pulverized coal is less than 200 meshes.

5. The method for preparing high-performance coal-water slurry by rapidly matching coal types as claimed in claim 1, wherein in the third step, the oscillation rotation speed is 160-220r/min, and the adsorption time is 6-8 h.

Technical Field

The invention relates to the technical field of coal water slurry preparation, in particular to a method for preparing high-performance coal water slurry by quickly matching coal types.

Background

China is a world with large coal reserves and a world with large coal consumption as main energy, but the use of coal brings about a serious environmental pollution problem. The coal water slurry has great potential in industrial application as a novel environment-friendly fuel. The coal water slurry is a coal-based fluid fuel and gasification raw material consisting of coal, water and additives, can be used for combustion power generation or gas supply of industrial boilers, kilns and power station boilers, and can also be used for producing chemical products such as synthetic ammonia, methanol, olefin, oil products, natural gas and the like by coal gasification. Research into slurry properties and obtaining coal water slurries with superior slurry properties are a necessary option for developing clean coal technology.

The coal water slurry additive is the most important influencing factor influencing the slurry performance. Due to the complexity of the macromolecular structure of the coal, the matching difficulty of the additive and the coal is increased, and the slurry performance is difficult to improve. The biggest difficulty in the research of the coal water slurry at present is the research of the adaptability of the additive and the coal, and the additives with different structures have different influences on the slurry performance. In previous researches, the matching property of the additive and coal is judged through pulping experiments, and the method is lack of pertinence and complex to operate.

Disclosure of Invention

The invention aims to provide a method for preparing high-performance coal water slurry by quickly matching coal types.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a method for preparing high-performance coal water slurry by quickly matching coal types comprises the following steps:

the method comprises the following steps: respectively preparing different additives into solutions with certain concentration, measuring the surface tension of different solutions at room temperature, subtracting the surface tension of the solutions from the surface tension of water at room temperature to obtain a difference value M, and ranking according to the following standard: a: m is more than 20 mN/M; b: 10< M <20 mN/M; c: m <10 mN/M;

step two: and (3) measuring the contact angle of the different additive solutions prepared in the step one on the surface of the coal, and measuring the contact angle reduction value N of the solutions on the surface of the coal within 30 seconds, wherein the solutions are graded according to the following standard: a: n >20 °; b: 10 ° < N <20 °; c: n <10 °;

step three: respectively placing a proper amount of coal powder into a sample solution prepared in the step one with a certain volume for oscillation adsorption, taking a proper amount of solution for uniformly dispersing coal particles after oscillation, measuring the Zeta value of the surface of the coal particles when the pH value is 7, and recording the absolute value of the potential of the surface of raw coal subtracted from the absolute value of the measured value as Z, wherein the levels are arranged according to the following standards: a: z is > 35; b: 15< Z < 35; c: z < 15;

step four: sorting according to grades of different additives in the first step to the third step: first-stage: AAA; and (2) second stage: AAB, ABA, BAA; third-stage: ABB, BAB, BBA, AAC, ACA, CAA,; and (4) fourth stage: BBB and below BBB;

step five: according to the grade determined in the fourth step, the additives in the first three grades are selected to be respectively subjected to a dry powder pulping experiment, the slurry is subjected to measurement of the viscosity concentration S and the water separation rate D, and the two performance grades are respectively sequenced: fixed viscosity concentration S: a: s is more than 65%; b: 61% < S < 65%; c: s < 61%; water separation rate D: a: d < 3%; b: 3% < D < 5%; c: d is greater than 5%;

step six: and selecting the additives required by the process according to the test result of the step five.

Preferably, in the step one, the surface tension is measured by a pendant drop method.

Preferably, in the first step, the additive is at least three of naphthalene-based, lignin-based, aliphatic-based, humic acid-based and melamine-based additives for coal water slurry.

Preferably, in the third step, the particle size of the pulverized coal is less than 200 meshes.

Preferably, in the third step, the oscillation rotation speed is 160-220r/min, and the adsorption time is 6-8 h.

Compared with the prior art, the method disclosed by the invention has the advantages that a series of parameter standards are formulated by measuring the surface tension, the contact angle and the like of the solution, the grades of different additives are judged to determine the adaptability of the coal and the additives, the judgment experiment process is reduced, and the matching performance and the matching efficiency between the additives and the coal are improved.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

The method comprises the following steps: additive solutions of naphthalene (naphthalene sulfonic acid formaldehyde condensate), lignin (lignosulfonate), aliphatic (sulfonated aldehyde ketone condensate) and humic acid (humate) were prepared in an amount of 5000mg/L, and the additive solutions were sequentially referred to as sample solution No. 1, sample solution No. 2, sample solution No. 3 and sample solution No. 4. Measuring the surface tension of the four different solutions at room temperature by a pendant drop method and sequencing according to gradesThe results are shown in Table 1. The surface tension value of water at room temperature is 72 mN.m^-1。

TABLE 1

Step two: the contact angles of sample solutions 1, 2, 3 and 4 at 5000mg/L on the surfaces of coal sample 1 (shenhua coal) and coal sample 2 (shenfu coal) were measured, and the contact angle decrease values thereof were measured within 30 seconds, and the results are shown in tables 2 and 3.

TABLE 2

	Coal sample 1 contact Angle reduction value N (°)	Grade
			Sample 1	22.13	A
Sample 2	13.34	B
			Sample 3	29.13	A
Sample No. 4	11.25	B

TABLE 3

	Coal sample 2 contact Angle reduction value N (°)	Grade
			Sample 1	20.08	A
Sample 2	15.61	B
			Sample 3	19.35	B
Sample No. 4	9.66	C

Step three: 0.5g of coal powder (air-drying base, particle size less than 200 meshes) is placed in 25mL of sample solution with concentration of 5000mg/L to be vibrated and adsorbed for 7h at the rotating speed of 200r/min, a proper amount of solution with uniformly dispersed coal particles after vibration is taken, the Zeta value of the surface of the coal particles when the pH value is 7 is measured, and the difference value of the absolute value of the potential of the surface of the raw coal subtracted from the absolute value of the measured absolute value is recorded, and the results are shown in tables 4 and 5.

TABLE 4

TABLE 5

	Coal sample 2Zeta (mv)	Difference in absolute value Z	Grade
				Sample 1	-54.08	28.47	B
Sample 2	-61.13	35.52	A
				Sample 3	-59.81	34.2	B
Sample No. 4	-35.64	10.03	C
				Shenfu raw coal	-25.61.	/	/

Step four: the grades measured by the different additives in the first, second and third steps are sorted, and the results are shown in tables 6 and 7. The larger the reduction degree of the contact angle within one minute in the step two is, the better the spreading capacity of the coal slurry on the surface of the coal is, the better wetting effect and the better adsorption effect can be achieved, the better promotion effect on reducing the viscosity of the coal water slurry is achieved, and in the step three, the larger the absolute value of the potential is, the larger the contribution to improving the stability of the coal water slurry is.

TABLE 6

	Coal sample 1	Grade
			Sample 1	BAB	Three-stage
Sample 2	ABA	Second stage
			Sample 3	BAA	Second stage
Sample No. 4	BBC	Four stages

TABLE 7

	Coal sample 2	Grade
			Sample 1	BAB	Three-stage
Sample 2	ABA	Second stage
			Sample 3	BBB	Four stages
Sample No. 4	BCC	Four stages

Step five: selecting a No. 1 sample, a No. 2 sample and a No. 3 sample, and respectively performing a dry powder pulping experiment on the coal sample 1; a No. 1 sample and a No. 2 sample are selected, and a dry powder pulping experiment is respectively carried out on the coal sample 2, the fixed coal powder content is 100g, and the additive amount is 0.3% (in dry basis proportion). Measuring a shear rate of 100S^-1The fixed viscosity concentration S of the coal water slurry under the condition of the viscosity of 1000 mPa.S; standing the slurry for seven days, measuring the water precipitation volume, and calculating the water precipitation rate D (D ═ V)₁/V₂×100％；V₁: volume of water precipitated, V₂: total volume of coal water slurry); the results are shown in tables 8 and 9;

TABLE 8

	Coal sample 1 fixed viscosity concentration S	Coal sample 1 water separation rate D	Grade
				Sample 1	65.3％	2.84％	AA
Sample 2	64.89％	2.33％	BA
				Sample 3	63.29％	10.13％	BC

TABLE 9

	Coal sample 2 fixed viscosity concentration S	Coal sample 2 water separation rate D	Grade
				Sample 1	65.56％	2.91％	AA
Sample 2	64.6％	4.17％	BB

Step six: sample No. 1 was selected as an additive for slurrying coal sample 1 and coal sample 2. The additive with the viscosity-fixing concentration S reaching A grade can be concentrated and reduced in viscosity in a targeted manner. Additives that achieve a water separation rate D of A or B rating can help improve the stability of the slurry for storage and transport.