阅读说明：本技术 一种判别高炉内部焦炭状态的方法 (Method for distinguishing coke state in blast furnace ) 是由 武吉 车玉满 甘秀石 党平 侯士彬 崔思强 邵思维 姜喆 梁金宝 于 2021-09-15 设计创作，主要内容包括：本发明涉及一种判别高炉内部焦炭状态的方法,对高炉内部焦炭进行取样；将取样焦炭研磨至200目以下,利用X-射线衍射分析计算得出不同取样点焦炭对应的石墨化微晶尺寸；将焦炭研磨成粉末后分别进行不同条件下的热处理试验,并进行X-射线衍射分析,计算得出不同条件热处理后焦炭对应的石墨化微晶尺寸,利用数据软件进行画图模拟出焦炭石墨化微晶尺寸随热处理后条件的变化规律；得出不同取样点对应的反应条件。优点是：有效掌握高炉生产过程中内部不同区域最高温度、停留时间及反应气氛参数,进而为高炉操作提供内部参数,使得高炉“黑箱”操作变得“透明化”。(The invention relates to a method for judging the state of coke in a blast furnace, which is used for sampling the coke in the blast furnace; grinding the sampled coke to below 200 meshes, and calculating to obtain the sizes of the graphitized microcrystals corresponding to the cokes at different sampling points by utilizing X-ray diffraction analysis; grinding coke into powder, respectively carrying out heat treatment tests under different conditions, carrying out X-ray diffraction analysis, calculating to obtain the sizes of the graphitized microcrystals corresponding to the coke subjected to heat treatment under different conditions, and utilizing data software to carry out drawing to simulate the change rule of the sizes of the graphitized microcrystals of the coke along with the conditions after heat treatment; obtaining the reaction conditions corresponding to different sampling points. The advantages are that: the highest temperature, residence time and reaction atmosphere parameters of different internal areas in the production process of the blast furnace are effectively mastered, so that internal parameters are provided for the operation of the blast furnace, and the operation of a black box of the blast furnace becomes transparent.)

1. A method for judging the coke state in a blast furnace is characterized by comprising the following steps:

1) sampling coke in the blast furnace;

2) grinding the sampled coke to below 200 meshes, and calculating to obtain the sizes of the graphitized microcrystals corresponding to the cokes at different sampling points by utilizing X-ray diffraction analysis;

3) respectively carrying out heat treatment tests on coke before entering a blast furnace under different conditions, grinding the coke, then carrying out X-ray diffraction analysis, calculating the sizes of the graphitized microcrystals corresponding to the coke after heat treatment under different conditions, and drawing by using data to simulate the change rule of the sizes of the graphitized microcrystals of the coke along with the conditions after heat treatment;

4) comparing the size data of the graphitized micro-crystals of the coke in the step 2) with the rule in the step 3), and further obtaining the reaction conditions corresponding to different sampling points in the step 2).

2. The method for determining the coke state inside the blast furnace according to claim 1, wherein the sample coke in the steps 1) and 2) is a coke sample in any area inside the blast furnace, and comprises one or more of tuyere coke, dead charge column coke and hearth coke.

3. The method for judging the state of coke in the blast furnace according to claim 1, wherein the heat treatment tests of the coke under different conditions in the step 3) are specifically as follows:

the highest temperature is 1000-2000 ℃, namely the constant temperature time after the temperature is increased to the highest temperature, and the reaction atmosphere in the temperature increasing and constant temperature process are constant; or 0 to 100% of CO and 0 to 100% of CO by volume₂、0～100％N₂And the reaction atmosphere of 0-100% of water vapor is subjected to a single-factor test, and the volume percentage is as follows: (CO)% + (CO)₂)％+(N₂) Percent + water vapor percent is 100 percent, and the highest temperature, the time for rising to the highest temperature and the time for keeping the highest temperature constant are not changed; or performing a single-factor test for a constant temperature time of 0-20 h when the temperature is raised to the highest temperature, namely keeping the heating highest temperature and the reaction atmosphere constant; or variable reaction conditions under multiple variable factors as described above.

4. The method for distinguishing the coke state inside the blast furnace according to claim 1, wherein the rule of the change of the size of the coke graphitized microcrystal before entering the blast furnace in the step 3) along with the conditions after the heat treatment is a test parameter fitting curve or curved surface of one or more factors of the heating temperature, the constant temperature time of the highest heating temperature and the reaction atmosphere.

5. The method of claim 1, wherein the graphitized crystallite size includes: average carbon pile height, layer spacing, or average number of layers of coke.

Technical Field

The invention belongs to the field of blast furnace ironmaking, and particularly relates to a method for judging the state of coke in a blast furnace.

Background

Blast furnace iron-making is the most main production link of ferrous metallurgy process, however, the blast furnace is a mobile packed bed which coexists in multiple phases and is full of chemical reaction, the internal reaction conditions and reaction states are not clear, the temperature measurement in the blast furnace is generally realized by pre-embedded thermocouples in the refractory material of the furnace body, the approximate corresponding temperature of the blast furnace on a certain charge level is obtained, and the specific temperature in the blast furnace and the coke state of the furnace burden are not clear.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a method for judging the state of coke in a blast furnace, which is used for detecting the property indexes of the sampled coke at a blast furnace tuyere and the sampled coke in the overhaul of the blast furnace, and utilizing the characteristics that the higher the temperature of the coke is, the higher the graphitization degree of the coke is, the larger the carbon accumulation height of the coke is, and the different reactions of the coke and iron slag at different temperatures, so as to reversely push the internal temperature and the working state of the blast furnace before blowing down or blowing out of the blast furnace.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a method for judging the coke state in a blast furnace comprises the following steps:

1) sampling coke in the blast furnace;

2) grinding the sampled coke to below 200 meshes, and calculating to obtain the sizes of the graphitized microcrystals corresponding to the cokes at different sampling points by utilizing X-ray diffraction analysis;

3) respectively carrying out heat treatment tests on coke before entering a blast furnace under different conditions, grinding the coke, then carrying out X-ray diffraction analysis, calculating the sizes of the graphitized microcrystals corresponding to the coke after heat treatment under different conditions, and drawing by using data to simulate the change rule of the sizes of the graphitized microcrystals of the coke along with the conditions after heat treatment;

4) comparing the size data of the graphitized micro-crystals of the coke in the step 2) with the rule in the step 3), and further obtaining the reaction conditions corresponding to different sampling points in the step 2).

The sample coke obtained in the step 1) and the step 2) is a coke sample in any area in the blast furnace, and comprises one or more of tuyere coke, dead material column coke and hearth coke.

The heat treatment tests of the coke in the step 3) under different conditions are as follows:

the highest temperature is 1000-2000 ℃, namely the constant temperature time after the temperature is increased to the highest temperature, and the reaction atmosphere in the temperature increasing and constant temperature process are constant; or 0 to 100% of CO and 0 to 100% of CO by volume₂、0～100％N₂And the reaction atmosphere of 0-100% of water vapor is subjected to a single-factor test, and the volume percentage is as follows: (CO)% + (CO)₂)％+(N₂) Percent + water vapor percent is 100 percent, and the highest temperature, the time for rising to the highest temperature and the time for keeping the highest temperature constant are not changed; or performing a single-factor test for a constant temperature time of 0-20 h when the temperature is raised to the highest temperature, namely keeping the heating highest temperature and the reaction atmosphere constant; or variable reaction conditions under multiple variable factors as described above.

The rule of the change of the size of the coke graphitized microcrystal before entering the blast furnace in the step 3) along with the condition after heat treatment is a test parameter fitting curve or curved surface of one or more factors of heating temperature, constant temperature time of the highest heating temperature and reaction atmosphere.

The graphitized crystallite size comprises: average carbon pile height, layer spacing, or average number of layers of coke.

Compared with the prior art, the invention has the beneficial effects that:

the method of the invention utilizes blast furnace tuyere sampling and blast furnace overhaul internal coke sampling to judge the internal coke state of the blast furnace and the internal reaction conditions of the blast furnace, thereby realizing the accurate description of the multi-zone state of the blast furnace. The highest temperature, residence time and reaction atmosphere parameters of different internal areas in the production process of the blast furnace are effectively mastered, so that internal parameters are provided for the operation of the blast furnace, and the operation of a black box of the blast furnace becomes transparent.

Drawings

FIG. 1 is a schematic diagram of the blast furnace of example 1 and different sampling points of the coke in the blast furnace.

FIG. 2 is a fitted graph of the average number of layers after high temperature graphitization of the coke according to example 1 versus temperature.

FIG. 3 is a schematic representation of the different sampling points of the blast furnace and the coke inside the blast furnace of example 2.

FIG. 4 is a fitted graph of the average number of layers after high temperature graphitization of the coke and the temperature of example 2.

FIG. 5 is a fitted graph of the average number of layers after high temperature graphitization of the coke and the temperature for example 3.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings, but it should be noted that the present invention is not limited to the following embodiments.

Example 1

The method for judging the coke state in the blast furnace comprises the following steps:

1) the blast furnace tuyere coke, dead charge column coke and hearth coke were sampled at multiple points and counted as S1, S2, S3 and S4, respectively, as shown in fig. 1.

2) Respectively grinding the sampling coke to below 200 meshes, and calculating by utilizing X-ray diffraction analysis to obtain the sizes of the coke graphitized microcrystals corresponding to the cokes at different sampling points, wherein the sizes of the graphitized microcrystals comprise: average carbon pile height Lc, interlayer spacing d (002), and average number of layers n of coke, wherein the graphitized crystallite sizes of sampling points S1, S2, S3, S4 are shown in Table 1.

TABLE 1 multipoint sampling Coke graphitization crystallite size

Sampling point	Lc(nm)	d(002)(nm)	n
				S1	1.76	0.34	5.26
S2	8.71	0.34	25.75
				S3	20.02	0.33	59.52
S4	24.17	0.33	72.03

3) Grinding coke into powder in a laboratory, respectively placing the coke in a high-temperature furnace, heating to 25 ℃, 1000 ℃, 1350 ℃, 1450 ℃, 1550 ℃ and 100 percent N₂And (3) performing atmosphere protection, keeping the highest temperature constant for 2 hours, performing X-ray diffraction analysis, and calculating to obtain the average number of coke microcrystal layers corresponding to the cokes at different sampling points, and fitting a curve of the relationship between the average number of layers and the temperature after the cokes are graphitized at the high temperature, as shown in fig. 2.

4) Comparing the size data of the coke graphitized microcrystal in the blast furnace in the step 2) with the fitted curve in the step 3), and further obtaining the temperatures approximately corresponding to different sampling points in the step 2) as shown in table 2.

TABLE 2 temperature State corresponding to the internal Multi-zone sampling points of the blast furnace

Sampling point	S1	S2	S3	S4
					Temperature/. degree.C	25	1375	1500	1530

Example 2

The method for judging the coke state in the blast furnace comprises the following steps:

1) respectively carrying out multi-point sampling on the blast furnace tuyere coke, and respectively recording the sampling results as S1, S2, S3, S4 and S5, as shown in FIG. 3;

2) respectively grinding the sampling coke to below 200 meshes, and calculating by utilizing X-ray diffraction analysis to obtain the sizes of the coke graphitized microcrystals corresponding to the cokes at different sampling points, wherein the sizes of the graphitized microcrystals comprise: average carbon pile height L of coke_cD distance between layers₍₀₀₂₎And an average number of layers n, wherein the graphitized crystallite sizes of the sampling points S1, S2, S3, S4, S5 are as shown in table 3.

TABLE 3 multipoint sampling coke graphitization crystallite size

Sampling point	S1	S2	S3	S4	S5
						Average number of layers n	45.26	54.75	59.52	72.03	73.89

3) Grinding raw coke into powder in a laboratory, and respectively placing the raw coke in different CO₂Under the condition of reaction atmosphere (the rest is N)₂) And (3) heating the high-temperature furnace to 1650 ℃ and keeping the temperature for 2h, then carrying out X-ray diffraction analysis on the sample after reaction, and calculating to obtain a fitting curve of the relation between the average layer number and the temperature after the raw material coke is graphitized after high-temperature treatment in different reaction atmospheres, as shown in figure 4.

4) Comparing the size data of the coke graphitized microcrystal in the blast furnace in the step 2) with the fitted curve in the step 3, and further obtaining the atmosphere approximately corresponding to different sampling points in the step 2) as shown in table 4.

TABLE 4 temperature State corresponding to the internal Multi-zone sampling points of the blast furnace

Sampling point	S1	S2	S3	S4	S5
						CO2/％	59	55	52	21	8

Example 3

The method for judging the coke state in the blast furnace comprises the following steps:

1) the blast furnace tuyere coke, dead charge column coke and hearth coke were sampled at multiple points and counted as S1, S2, S3 and S4, respectively, as shown in fig. 1.

2) Respectively grinding the sampling coke to below 200 meshes, and calculating by utilizing X-ray diffraction analysis to obtain the sizes of the coke graphitized microcrystals corresponding to the cokes at different sampling points, wherein the sizes of the graphitized microcrystals comprise: average carbon pile height Lc, interlayer spacing d (002), and average number of layers n of coke, wherein the graphitized crystallite sizes at sample points S1, S2, S3, S4 are shown in table 5.

TABLE 5 multipoint sampling coke graphitization crystallite size

Sampling point	Lc(nm)	d(002)(nm)	n
				S1	1.76	0.34	5.26
S2	8.71	0.34	8.75
				S3	20.02	0.33	21.52
S4	24.17	0.33	30.03

3) Grinding coke into powder in a laboratory, respectively placing the coke in a high-temperature furnace, heating to 25 ℃, 1000 ℃, 1350 ℃, 1450 ℃, 1550 ℃ and 70 percent of N₂+20％CO+10％CO₂) Atmosphere protection, constant temperature at maximum 1And 5h, carrying out X-ray diffraction analysis, and calculating to obtain the average number of coke microcrystal layers corresponding to the cokes at different sampling points, wherein a curve is fitted by the relationship between the average number of layers and the temperature after the cokes are graphitized at high temperature, as shown in FIG. 5.

4) Comparing the size data of the coke graphitized microcrystals inside the blast furnace in the step 2) with the fitted curve in the step 3), and further obtaining temperatures approximately corresponding to different sampling points in the step 2) as shown in table 6.

TABLE 6 temperature State corresponding to the internal Multi-zone sampling points of the blast furnace

Sampling point	S1	S2	S3	S4
					Temperature/. degree.C	420	950	1390	1510

Example 4

The method for judging the coke state in the blast furnace comprises the following steps:

1) respectively carrying out multi-point sampling on the blast furnace tuyere coke, and respectively recording the sampling results as S1, S2, S3, S4 and S5, as shown in FIG. 3;

2) grinding the sampled coke to below 200 meshes, and analyzing and calculating by X-ray diffraction to obtain different samplesCoke graphitized crystallite sizes corresponding to the point coke, the graphitized crystallite sizes including: average carbon pile height L of coke_cD distance between layers₍₀₀₂₎And an average number of layers n, wherein the graphitized crystallite sizes of the sampling points S1, S2, S3, S4, S5 are as shown in table 7.

TABLE 7 multipoint sampling coke graphitization crystallite size

Sampling point	S1	S2	S3	S4	S5
						Average number of layers n	40.26	50.75	53.52	65.03	69.89

3) Grinding raw coke into powder in a laboratory, and respectively placing the raw coke in different CO₂Under the condition of reaction atmosphere (the rest is N)₂) Heating to 25 deg.C, 1000 deg.C, 1350 deg.C, 1450 deg.C, 1550 deg.C in high temperature furnace, holding the temperature for 2 hr, performing X-ray diffraction analysis on the reacted sample, calculating to obtain average graphitized coke after the raw coke is treated in different reaction atmospheres and different temperaturesAnd fitting the relation between the number of layers and the temperature and atmosphere to a pseudo-curved surface.

4) Comparing the size data of the coke graphitized microcrystal in the blast furnace in the step 2) with the fitted curved surface in the step 3, so as to obtain the temperature and atmosphere conditions approximately corresponding to different sampling points in the step 2), as shown in tables 8 and 9.

TABLE 8 temperature State corresponding to the internal Multi-zone sampling points of the blast furnace

Sampling point	S1	S2	S3	S4
					Temperature/. degree.C	320	850	1330	1510

TABLE 9 temperature State corresponding to the internal Multi-zone sampling points of the blast furnace

Sampling point	S1	S2	S3	S4	S5
						CO2/％	62	54	50	20	10

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