A detection and evaluation method for distinguishing the coking properties of non - caking coal

Abstract

A detection and evaluation method for distinguishing the coking properties of non - caking coal belongs to the technical field of blended coal coking evaluation; the technical problem to be solved is: to provide an improvement on the detection and evaluation method for distinguishing the coking properties of non - caking coal; the technical solution adopted to solve the above - mentioned technical problem is as follows: it includes the following steps: Preparation of samples required for experiments: According to the method of GB / T474 - 2008, the non - caking coal to be tested is made into samples smaller than 0.2mm; Detection of the self - binding G of non - caking coal: For the coal sample to be tested in S1, its self - binding G is detected according to the method of GB / T5447 - 2014; The caking substances and non - caking coal are proportioned according to different ratios, mixed evenly, burned into coke residues, and the coking differences of non - caking coal are judged according to the block size of the coke residues and the enlarged binding value to obtain the binding G' of the mixed sample; After the experiment according to the above steps, based on the value of G' as a reference, the coking properties of non - caking coals with close indexes are distinguished; This invention is applied to the detection of the coking properties of non - caking coal.

Description

Technical Field

[0001] A detection and evaluation method for distinguishing the coking properties of non-caking coal belongs to the technical field of blended coal coking evaluation. Background Art

[0002] In the process of blended coal coking production, in order to reduce costs, sometimes it is necessary to blend in some non-caking coal samples, such as non-caking coal or lean coal. Classified by degree of metamorphism, one is low-metamorphism coal, including long-flame coal, non-caking coal, etc., and the other is high-metamorphism coal, including lean coal or anthracite, etc. During the blending process of the above-mentioned several types of coal, there are great differences in coking properties, mainly manifested in that some coal will consume the binding of other coal in the blended coal when participating in the blending, while some coal has no influence on the binding of other coal in the blended coal when participating in the blending. Eventually, this difference will affect the production coke pushing current, cold strength, and hot strength of coke. However, due to its non-binding and non-swelling characteristics, general coal quality analysis methods including indexes such as caking index, plastic layer index, Gieseler fluidity, Audibert-Arnu dilatation, and free swelling number cannot obtain the analysis value and the softening characteristic curve of the coal, so it cannot be distinguished by the above indexes. Summary of the Invention

[0003] In order to overcome the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an improvement of a detection and evaluation method for distinguishing the coking properties of non-caking coal.

[0004] In order to solve the above technical problem, the technical solution adopted by the present invention is: A detection and evaluation method for distinguishing the coking properties of non-caking coal, comprising the following steps:

[0005] S1: Preparation of samples required for the experiment: According to the method of GB / T474-2008 of the national standard, make the non-caking coal to be tested into samples smaller than 0.2 mm;

[0006] S2: Detection of the self-binding G of non-caking coal: For the coal sample to be tested in S1, detect its self-binding G according to the method of GB / T5447-2014 of the national standard;

[0007] S3: Mix the caking substances and non-caking coal according to different ratios, mix them evenly, burn them into coke residues, and judge the coking difference of non-caking coal according to the lump size of the coke residues and the enlarged binding value to obtain the binding G' of the mixed sample;

[0008] S4: According to the value of G' after the experiment in step S3 above as a reference, distinguish the coking properties of non-caking coal with similar indexes.

[0009] The non-caking coal specifically uses lean coal or non-caking coal.

[0010] In the step S1, the proportion of the sample with a particle size of 0.1 - 0.2 mm in the unbonded coal sample to be measured is between 20 - 35%.

[0011] In the step S2, specifically, anthracite and the coal sample to be measured are mixed in a ratio of 3:3, stirred, weighted, burned, put into a drum, weighed, and the result is calculated, which is represented by the G value.

[0012] In the step S3, the caking agent used is made into a sample with a particle size less than 0.2 mm according to the method of GB / T474 - 2008. The specific steps for detecting the caking G' of the mixed sample are as follows:

[0013] Weigh the caking agent and the coal sample to be measured with a caking crucible, mix the two according to the set ratio, and stir evenly for 2 - 5 minutes.

[0014] After that, press a pressure block on the press and let it stand for 30 - 60 seconds. Cover the crucible lid, put the crucible together with the pressure block into a high-temperature furnace heated to 850 ± 10 °C, close the chimney and coke for 15 - 20 minutes, and then take it out.

[0015] Place the taken-out crucible at room temperature to cool for a period of time, then transfer it to a desiccator. When it cools down to room temperature, take it out and weigh it. Rotate the coke residue twice with a caking drum. After that, weigh the weight of the coke blocks > 1 mm respectively, and calculate the caking G' of the mixed sample = (30m1 + 70m2) / m + 10.

[0016] Where: m represents the weight of the coke residue after burning, in g.

[0017] m1 represents the weight of the coke residue > 1 mm after the first rotation of the drum, in g.

[0018] m2 represents the weight of the coke residue > 1 mm after the second rotation of the drum, in g.

[0019] The mixing ratio of the caking agent and the coal sample to be measured is 0.5:5.5 - 1:5.

[0020] When the crucible is just put into the high-temperature furnace, the temperature will drop. Ensure that the temperature in the high-temperature furnace returns to 850 ± 10 °C within 6 minutes after putting the crucible. Otherwise, step S3 needs to be repeated.

[0021] The characteristics of the caking agent meet the conditions: ash content ≤ 0.5, coking value 55 - 60, sulfur content ≤ 0.70, chlorine content ≤ 100 mg / kg, softening point 105 - 110 °C, toluene insoluble matter ≤ 20%, quinoline insoluble matter ≤ 10%.

[0022] Use a caking drum to rotate the coke residue twice. The set rotation speed is 50 r / min and it rotates 250 r.

[0023] The beneficial effects of the present invention compared with the prior art are as follows: The detection and evaluation method for distinguishing the coking performance of non-caking coal provided by the present invention mixes a certain amount of caking substances into the non-caking coal, mixes them evenly, burns them into coke residues, and can judge the coking differences of non-caking coal according to the size of the coke residues and the enlarged caking value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the drawings:

[0025] Figure 1 It is a flowchart of the method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] As Figure 1 shown, a detection and evaluation method for distinguishing the coking performance of non-caking coal according to the present invention includes the following steps:

[0027] S1: Preparation of samples required for experiments: According to the method of GB / T474-2008 of the national standard, the non-caking coal to be tested is made into samples smaller than 0.2 mm;

[0028] S2: Detection of the self-caking G of non-caking coal: For the coal sample to be tested in S1, its self-caking G is detected according to the method of GB / T5447-2014 of the national standard;

[0029] S3: Mix the caking substances and non-caking coal according to different ratios, mix them evenly, burn them into coke residues, judge the coking differences of non-caking coal according to the size of the coke residues and the enlarged caking value, and obtain the caking G' of the mixed sample;

[0030] S4: According to the value of G' after the experiment in step S3 above as a reference, distinguish the coking performance of non-caking coal with similar indexes.

[0031] The non-caking coal specifically uses lean coal or non-caking coal.

[0032] In step S1, the proportion of samples with a size of 0.1-0.2 mm in the non-caking coal sample to be tested is between 20-35%.

[0033] In step S2, specifically, anthracite and the coal sample to be tested are mixed in a ratio of 3:3, stirred, weighted, burned, rotated in a drum, weighed, and the results are calculated, and the value is represented by the G value.

[0034] The caking substances used in step S3 are made into samples smaller than 0.2 mm according to the method of GB / T474-2008 of the national standard. The specific steps for detecting the caking G' of the mixed sample are as follows:

[0035] Weigh the caking substances and the coal sample to be tested with a caking crucible, mix the two according to the set ratio, stir evenly, and the stirring time is 2-5 min;

[0036] After that, press a pressing block on the pressure vessel and let it stand still for 30 - 60 s. Cover the crucible lid, and place the crucible together with the pressing block into a high-temperature furnace heated to 850 ± 10 °C. After coking with the chimney closed for 15 - 20 min, take it out;

[0037] Place the taken-out crucible at room temperature to cool for a period of time and then transfer it to a desiccator. When it cools down to room temperature, take it out and weigh it. Rotate the coke residue twice with a bonding drum. After that, weigh the weight of the coke lumps > 1 mm respectively, and calculate the bonding of the mixed sample G’ = (30m1 + 70m2) / m + 10;

[0038] Where: m: represents the weight of the coke residue after burning, unit g;

[0039] m1: represents the weight of the coke residue > 1 mm after the first drum rotation, unit g;

[0040] m2: represents the weight of the coke residue > 1 mm after the second drum rotation, unit g.

[0041] The mixing ratio of the caking substance and the coal sample to be measured is 0.5:5.5 - 1:5.

[0042] When the crucible is just put into the high-temperature furnace, the temperature will drop. Ensure that the temperature in the high-temperature furnace resumes to 850 ± 10 °C within less than 6 min after putting the crucible. Otherwise, step S3 needs to be repeated.

[0043] The characteristics of the caking substance meet the conditions: ash content: ≤0.5, coking value 55 - 60, sulfur content ≤0.70, chlorine content ≤100 mg / kg, softening point 105 - 110 °C, toluene insoluble matter ≤20%, quinoline insoluble matter ≤10%.

[0044] Use a bonding drum to rotate the coke residue twice, set the rotation speed to 50 r / min, and rotate for 250 r.

[0045] The detection and evaluation method for distinguishing the coking performance of non-caking coal provided by the present invention solves the technical problem that it is impossible to accurately distinguish the coking performance of non-caking coal due to similar conventional analysis indexes. Usually, when evaluating coal quality, the caking index and other plastic indexes are often used as references to judge the level of its coking performance. However, because the caking of non-caking coal is very low or almost zero, other plastic indexes cannot be obtained either, and there is no volume change curve after heating, resulting in the inability to distinguish the level of its coking performance, thus causing trouble in the application of non-caking coal. In the present invention, a certain amount of caking substance is added to the non-caking coal, mixed evenly, and burned into coke residue. The coking difference of non-caking coal is judged according to the particle size of the coke residue and the enlarged caking value.

[0046] Refer to the appendix Figure 1Schematic diagram of the detection and evaluation method for distinguishing the coking properties of non-caking coal shown in the figure. The present invention mainly adopts the following steps:

[0047] (1) Preparation of samples required for the experiment: According to the method of GB / T474-2008, the coal to be tested is made into samples less than 0.2mm.

[0048] (2) Detection of the self-bonding of non-caking coal: For the coal sample to be tested in (1), its self-bonding is detected according to the method of GB / T5447-2014. The ratio of anthracite to the coal sample is 3:3. After mixing, weighing, burning, tumbling in a drum, and weighing, the result is calculated and represented by the G value.

[0049] (3) Detection of the change in the bonding of the mixed sample after the caking substance and non-caking coal are mixed in different proportions: The steps are as follows: Weigh the caking substance and the coal sample to be tested in (1) with a crucible. The caking substance and the coal sample to be tested are mixed in the proportions of 2.5:3.5, 2:4, 1:5, 0.5:5.5, and 0:6 respectively. Stir evenly with a caking index mixer for 2 minutes, using the same method as GB / T5447-2014. Press the upper press block and let it stand for 30 seconds to make the surface flat. Cover the crucible lid, and put the crucible together with the press block into a high-temperature furnace heated to 850°C. After coking for 15 minutes with the chimney closed, take it out. The temperature will drop when the crucible is just put in. Ensure that the temperature returns to 850±10°C within less than 6 minutes after being put in, otherwise the experiment is invalid. And ensure that the coking time for each different proportion of mixed coal is the same. Place the taken-out crucible at room temperature to cool for 5 minutes and then transfer it to a desiccator. When it cools to room temperature, take it out and weigh it. Rotate the coke residue in a drum twice at 50r / min, 250 revolutions each time for 5 minutes. After that, weigh the weight of the coke blocks >1mm respectively. The bonding made by this method is denoted as G'.

[0050] (4) Calculate G'=(30m1 + 70m2) / m + 10. Where:

[0051] m: represents the weight of the coke residue after burning, in g;

[0052] m1: represents the weight of the coke residue >1mm after the first tumbling in the drum, in g;

[0053] m2: represents the weight of the coke residue >1mm after the second tumbling in the drum, in g.

[0054] In step (3), the caking substance is also made into samples less than 0.2mm, and then mixed evenly with the non-caking coal.

[0055] Selection of the binding substance of the present invention: Select a binding substance with relatively stable properties, ash content: ≤0.5, coking value 55 - 60, sulfur content ≤0.70, chlorine content ≤100 mg / kg, softening point 105 - 110 °C, toluene insoluble matter ≤20%, quinoline insoluble matter ≤10%.

[0056] The results of the present invention are analyzed below through Table 1.

[0057]

[0058] Table 1 Experimental results of different mixing ratios using the detection and evaluation method for distinguishing the coking properties of non - caking coal according to the present invention.

[0059] (5) Based on the above experimental results, using the national standard GB / T5447 - 2014 method to detect its self - binding, when the ratio of anthracite to coal sample is mixed at 3:3, and the binding substance is mixed with the coal sample to be tested in different ratios, the ratio between the two is in the range of 2.5:3.5 to 1.5:4.5 and measuring the coal sample to be tested alone, none of them can effectively distinguish the coking properties of non - caking coal; while when the ratio between the binding substance and the coal sample to be tested is in the range of 0.5:5.5 to 1:5, the binding index of non - caking coal can be better distinguished, and then the coking properties can be accurately evaluated.

[0060] Regarding the specific structure of the present invention, it should be noted that the connection relationships between the various component modules adopted in the present invention are definite and achievable. Except for the special descriptions in the embodiments, the specific connection relationships can bring corresponding technical effects, and on the premise of not relying on the execution of corresponding software programs, the technical problems proposed by the present invention can be solved. The models and connection methods of the components, modules, and specific components in the present invention, except for the specific descriptions, all belong to the prior art such as publicly available patents, publicly available journal papers, or common general knowledge that those skilled in the art can obtain before the filing date, and need not be elaborated. Thus, the technical solution provided in this case is clear, complete, and achievable, and the corresponding physical products can be reproduced or obtained according to this technical means.

[0061] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A detection and evaluation method for distinguishing the coking properties of non - caking coal, characterized in that: It includes the following steps: S1: Preparation of samples required for the experiment: According to the method of GB / T474-2008 of the national standard, the unbonded coal to be tested is made into samples smaller than 0.2mm. S2: Detection of the self-bonding G of the unbonded coal: For the coal sample to be tested in S1, its self-bonding G is detected according to the method of GB / T5447-2014 of the national standard. S3: The caking substances and the unbonded coal are proportioned according to the ratio, mixed evenly, and burned into coke residues. The coking differences of the unbonded coal are judged according to the lump size of the coke residues and the enlarged caking value to obtain the caking G' of the mixed sample; the mixing ratio of the caking substances and the coal sample to be tested is 0.5:5.5 to 1:

5. S4: After the experiment in step S3 above, based on the value of G' as a reference, the coking properties of the unbonded coals with similar indexes are distinguished.

2. The detection and evaluation method for distinguishing the coking performance of non-bonded coal according to claim 1, characterized in that: The unbonded coal specifically uses lean coal or non-caking coal.

3. The detection and evaluation method for distinguishing the coking performance of non-bonded coal according to claim 1, characterized in that: In step S1, the proportion of the samples of 0.1-0.2mm in the unbonded coal sample to be tested is between 20-35%.

4. The detection and evaluation method for distinguishing the coking performance of non - caking coal according to claim 1, characterized in that: In step S2, specifically, anthracite and the coal sample to be tested are mixed in a ratio of 3:3, stirred, weighted, burned, rotated in a drum, weighed, and the result is calculated, which is expressed by the G value.

5. The detection and evaluation method for distinguishing the coking performance of non-bonded coal according to claim 1, wherein: The caking substances used in step S3 are made into samples smaller than 0.2mm according to the method of GB / T474-2008 of the national standard. The specific steps for detecting the caking G' of the mixed sample are as follows: Weigh the caking substances and the coal sample to be tested with a caking crucible, mix the two according to the set ratio, and stir evenly for 2-5 minutes. After that, press a briquette on the press and let it stand for 30-60 seconds, cover the crucible lid, put the crucible together with the briquette into a high-temperature furnace heated to 850±10°C, close the chimney and coke for 15-20 minutes, and then take it out. Place the taken-out crucible at room temperature to cool for a period of time and then transfer it to a desiccator. When it cools down to room temperature, take it out and weigh it. Rotate the coke residue twice with a caking drum. After that, weigh the weight of the coke lumps >1mm respectively, and calculate the caking G' of the mixed sample = (30m1 + 70m2) / m + 10. Where: m: represents the weight of the coke residue after burning, in g; m1: represents the weight of the coke residue >1mm after the first rotation of the drum, in g; m2: represents the weight of the coke residue >1mm after the second rotation of the drum, in g.

6. The detection and evaluation method for distinguishing the coking performance of non - caking coal according to claim 5, characterized in that: When the crucible is just put into the high-temperature furnace, the temperature will drop. Ensure that the temperature in the high-temperature furnace returns to 850±10°C within less than 6 minutes after the crucible is put in. Otherwise, step S3 needs to be repeated.

7. The detection and evaluation method for distinguishing the coking performance of non - caking coal according to claim 5, wherein: The characteristics of the caking substances meet the conditions: ash content: ≤0.5, coking value 55-60, sulfur content ≤0.70, chlorine content ≤100mg / kg, softening point 105-110°C, toluene insoluble matter ≤20%, quinoline insoluble matter ≤10%.

8. The detection and evaluation method for distinguishing the coking performance of non - caking coal according to claim 5, characterized in that: The set rotation speed for rotating the coke residue twice with a caking drum is 50r / min, and it rotates 250r.

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