Coking coal mixing grade judgment method

Abstract

The invention relates to a method for judging the blending grade of coking coal, which comprises the following steps of: according to different types of coking coal, combining the proportion of vitrinite random reflectivity (Rran) distributed in a certain section with a vitrinite random reflectivity standard deviation (S), calculating the blending grade index (DH) of the coking coal, and judging the blending grade of the coking coal. The coking coal is classified into weakly caking coal, 1 / 2 medium caking coal, gas coal, gas-fat coal, 1 / 3 coking coal, fat coal, coking coal, lean coal, meager lean coal and meager coal. Compared with the prior art, the method disclosed by the invention has the beneficial effects that the blending grades of the coking coals of different coal types are determined according to the proportion condition of the distribution interval of the vitrinite random reflectivity of the coking coals and in combination with the standard deviation of the vitrinite random reflectivity. The use proportion of the blended coal in coal blending is reasonably utilized, the coal blending cost is reduced, the coke quality is stabilized, and the comprehensive benefits of enterprises are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coking, and in particular relates to a method for judging the blending grade of coking coal. Background Art

[0002] Coking with single-type coal blending plays an important role in stabilizing the quality of coke. However, with the increasing shortage of high-quality coking coal resources in my country, the price of single-type coal is high. Under the demand of coking enterprises to reduce costs, the use of single-type coal has been greatly reduced. At the same time, driven by profit, suppliers mix washed clean coal to different degrees. This kind of mixed coal is very different from the true single-type coal in terms of process properties. For coking enterprises, how to judge whether coking coal is mixed coal and the degree of mixed coal is a very important task, which is directly related to its production cost and coke quality.

[0003] According to the industrial analysis of coal, conventional indicators such as volatile matter, caking index, Kiel fluidity and Oa expansion cannot reflect the mixed coal situation. At present, based on the national standard GB / T 6948-2008 "Method for Microscopic Determination of Vitrinite Reflectance of Coal", the standard deviation of vitrinite reflectance and the number of notches in the reflectance distribution diagram are used to determine whether the commercial coal is mixed coal, and the degree of mixing is distinguished by coding 0 to 5. However, this method has the problem of unclear basis for judging notches, what kind of shape can be determined as a notch, and under what circumstances it is not determined as a notch; in addition, the standard deviation is not clearly expressed when used as a division indicator, which is easy to cause misunderstandings to operators. For example, codes 3, 4 and 5 all require standard deviations > 0.2%, which is inappropriate. Therefore, this method is complex to operate and highly professional, and is not suitable for daily coal blending applications in enterprises. Patent document 202210040010.2 and patent document 202010864475.0 propose a method for identifying mixed coal using the Kiel fluidity characteristic index, but this method is only applicable to coking coal, fat coal and some 1 / 3 coking coal, and the degree of mixed coal judgment is relatively broad, lacking judgment on all types of coal, and has little guiding significance for actual production.

[0004] Therefore, based on the national standard GB / T 6948-2008 "Method for determination of vitrinite reflectance under microscope of coal", according to different types of coking coal, the standard deviation of vitrinite random reflectance (S) and the random reflectance of vitrinite (R ran ) calculates the coking coal blending grade index (DH). The judgment method is simple and fast, and can clarify the blending grades of different types of coking coals, guide its application in coal blending coking, and has good practicality and promotion in the process of coal blending coking. Summary of the invention

[0005] The invention provides a method for judging the blending grade of coking coal, which is applicable to all types of coking coal and clarifies the blending grade of coking coal, and has important guiding significance in adjusting the coal blending ratio and stabilizing the quality of coke.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for determining the blending grade of coking coal, according to different types of coking coal, the vitrinite random reflectance (R ran ) in a certain interval is combined with the standard deviation (S) of vitrinite random reflectance to calculate the coking coal blending grade index (DH) and judge the coking coal blending grade.

[0008] The coking coal is classified into weakly sticky coal, 1 / 2 medium sticky coal, gas coal, gas fat coal, 1 / 3 coking coal, fat coal, coking coal and lean coal, lean lean coal, and lean coal.

[0009] The method for determining the blending grade of weakly sticky coal, 1 / 2 medium sticky coal and gas coal is as follows:

[0010] Calculate the coking coal blending grade index DH, DH Q =lg (s+a) +S, where: S is the standard deviation of vitrinite random reflectance, a is the proportion of vitrinite random reflectance distribution <0.5 interval;

[0011] When DH Q When <-0.7, it is a single type of coal;

[0012] When -0.7≤DH Q When <-0.57, it is mixed coal level I;

[0013] When -0.57≤DH Q When <-0.5, it is mixed coal level II;

[0014] When -0.5≤DH Q When <-0.4, it is mixed coal level III;

[0015] When DH Q When ≥-0.4, it is mixed coal grade IV.

[0016] The method for determining the blending grade of gas fertilizer coal and 1 / 3 coking coal is as follows:

[0017] Calculate the coking coal blending grade index DH, DH 1 / 3 =lg (s+b) ; Where: S is the standard deviation of vitrinite random reflectance, b is the percentage of the maximum value of vitrinite random reflectance minus 0.6;

[0018] When DH 1 / 3 When ≤-1.07, it is a single type of coal;

[0019] When -1.07<DH 1 / 3 When <-1.02, it is mixed coal level I;

[0020] When -1.02≤DH 1 / 3 When <-0.92, it is mixed coal level II;

[0021] When DH 1 / 3 When ≥-0.92, it is mixed coal grade III.

[0022] The method for determining the blending grade of fat coal is:

[0023] Calculate the coking coal blending grade index DH, DH F =lg s -c; where: S is the standard deviation of the random reflectance of vitrinite, c is the proportion of 0.85 to 1.5 in the distribution of random reflectance of vitrinite;

[0024] When DH F When ≤-2, it is a single type of coal;

[0025] When -2<DH F When <-1.66, it is mixed coal level I;

[0026] When -1.66≤DH F When <-1.15, it is mixed coal level II;

[0027] When -1.15≤DH F When <-0.96, it is mixed coal level III;

[0028] When DHF≥-0.96, it is mixed coal level IV.

[0029] The method for determining the blending grade of coking coal is:

[0030] Calculate the coking coal blending grade index DH, DH J =lg s -c; where: S is the standard deviation of the random reflectance of vitrinite, and c is the proportion of vitrinite random reflectance distribution between 0.85 and 1.5.

[0031] When DH J When ≤-1.95, it is a single type of coal;

[0032] When -1.95<DH J When <-1.05, it is mixed coal level I;

[0033] When -1.05≤DH J When <-0.96, it is mixed coal level II;

[0034] When -0.96≤DH J When <-0.89, it is mixed coal level III;

[0035] When DH J When ≥-0.89, it is mixed coal grade IV.

[0036] The method for determining the blending grade of lean coal, lean lean coal and lean coal is as follows:

[0037] Calculate the coking coal blending grade index DH, DH S =lg (s+b) ; S is the standard deviation of vitrinite random reflectance, b is the minimum value of vitrinite random reflectance plus the percentage outside 0.6;

[0038] When DH S When ≤-1.07, it is a single type of coal;

[0039] When -1.07<DH S When <-1.02, it is mixed coal level I;

[0040] When -1.02≤DH S When <-0.96, it is mixed coal level II;

[0041] When -0.96≤DH S When <-0.89, it is mixed coal level II;

[0042] When DH S When ≥-0.89, it is mixed coal level III.

[0043] During the coal blending process, coking coal of grades III and IV are eliminated based on the judgment results of the coking coal blending grade, the proportion of coking coal of grade II is 5% to 15%, and the proportion of coking coal of grade I is 8% to 20%, so as to stabilize the quality of coke.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention determines the blending grade of coking coal of different types of coal according to the proportion of the distribution interval of the vitrinite random reflectance of the coking coal and the standard deviation of the vitrinite random reflectance. The proportion of the blended coal in coal blending is reasonably utilized to reduce the coal blending cost, stabilize the coke quality, and improve the comprehensive benefits of the enterprise. DETAILED DESCRIPTION

[0046] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. Based on the examples in the present invention, all other examples obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0047] Example 1: Determination of blending grade of weakly caking coal, 1 / 2 medium caking coal and gas coal.

[0048] The random reflectance distribution and standard deviation of vitrinite random reflectance of 1 / 2 medium-coking coal 1 are shown in Table 1.

[0049] Table 1 1 / 2 medium sticky coal 1

[0050]

[0051] 1 / 2 Medium-coking coal 1 The proportion of random reflectance distribution of vitrinite <0.5 is a=0.412, the standard deviation of random reflectance of vitrinite is S=0.076, DH Q =-0.24 (>-0.4) belongs to Class IV mixed coal. The part with random reflectance distribution of vitrinite <0.5 is generally composed of lignite and long flame coal, which is not good for the quality of coke in coal blending. It is recommended to suspend the use of 1 / 2 medium coking coal 1 in coal blending and coking.

[0052] The random reflectance distribution and standard deviation of vitrinite random reflectance of gas coal 1 are shown in Table 2.

[0053] Table 2 Gas coal 1

[0054]

[0055] Gas coal 1 vitrinite random reflectance distribution <0.5 interval proportion a=0.186, vitrinite random reflectance standard deviation S=0.056, DH Q =-0.56(-0.57≤DH Q <-0.5) belongs to Class II mixed coal. The part with random reflectance distribution of vitrinite <0.5 is generally lignite or long flame coal, which is not good for the quality of coke in coal blending. It is recommended that the proportion of gas coal 1 in coal blending and coking be controlled at 6%.

[0056] Example 2: Determination of the blending grade of gas fertilizer coal and 1 / 3 coking coal.

[0057] The random reflectance distribution and standard deviation of vitrinite random reflectance of gas fertilizer coal 1 are shown in Table 3.

[0058] Table 3 Gas Fertilizer Coal 1

[0059]

[0060] The standard deviation of random reflectance of vitrinite of gas fertilizer coal 1 is S = 0.075, the proportion of the maximum value of random reflectance of vitrinite minus 0.6 (1.15-0.6) is b = 0.019, DH 1 / 3 =-1.03(-1.07<DH 1 / 3 <-1.02) belongs to Class I mixed coal. It is recommended that the proportion of gas fertilizer coal 1 in coal blending for coking be controlled at 10%, and that it be blended with coking coal with good coking properties, which can increase the proportion of non-sticky coal or lean coal and reduce the cost of coal blending.

[0061] The random reflectivity distribution and standard deviation of vitrinite random reflectivity of 1 / 3 coking coal 1 are shown in Table 4.

[0062] Table 4 1 / 3 Coking coal 1

[0063]

[0064] 1 / 3 Coking coal 1 vitrinite random reflectance standard deviation S = 0.058, vitrinite with the maximum reflectance value minus 0.6 (1.05-0.6) outside the proportion b = 0, DH 1 / 3 =-1.24(DH 1 / 3 ≤-1.07) belongs to a single type of coal. It is recommended that 1 / 3 coking coal 1 be used in the coking process according to the change in coke quality, and the proportion of use can be appropriately increased to replace part of the fat coal and reduce the cost of coal blending.

[0065] Example 3: Determination of blending grade of fat coal

[0066] The random reflectance distribution and standard deviation of vitrinite random reflectance of fat coal 1 are shown in Table 5.

[0067] Table 5 Fat coal 1

[0068]

[0069] The random reflectance distribution of vitrinite in fat coal 1 is 0.85-1.5, accounting for c = 0.687, and the standard deviation of random reflectance of vitrinite is S = 0.078, DH F =-1.79(-2<DH F <-1.66) belongs to Class I mixed coal; it is recommended that the proportion of fat coal 1 used in coal blending for coking be controlled at 12%.

[0070] The random reflectance distribution and standard deviation of vitrinite random reflectance of fat coal 2 are shown in Table 6.

[0071] Table 6 Fat coal 2

[0072]

[0073] The random reflectance distribution of fat coal 2 vitrinite is 0.85-1.5, accounting for c = 0.989, and the standard deviation of random reflectance of vitrinite is S = 0.045, DH F =-2.34(DH F ≤-2) belongs to a single type of coal; it is recommended that fat coal 1 be used as the main type of coal in coal blending and coking.

[0074] Example 4: Determination of the blending grade of coking coal.

[0075] The distribution of random reflectance of vitrinite and the standard deviation of random reflectance of vitrinite of coking coal 1 are shown in Table 7.

[0076] Table 7 Coking coal 1

[0077]

[0078] Coking coal 1 vitrinite random reflectivity distribution 0.85-1.5 proportion c = 0.34, vitrinite random reflectivity standard deviation S = 0.298, DH J =-0.87(DH J ≥-0.89) belongs to Class IV mixed coal. It is a serious mixed coal, which is not conducive to the stability of coke quality. It is recommended that coking coal 1 be suspended in coal blending and coking.

[0079] The distribution of random reflectance of vitrinite and the standard deviation of random reflectance of vitrinite of coking coal 2 are shown in Table 8.

[0080] Table 8 Coking coal 2

[0081]

[0082] Coking coal 2 vitrinite random reflectivity distribution 0.85-1.5 proportion c = 0.992, vitrinite random reflectivity standard deviation S = 0.045, DH J =-2.34(DH J ≤-1.95) belongs to a single type of coal. It is recommended that coking coal 2 be used as the main type of coal in coal blending and coking.

[0083] Example 5: Determination of the blending grade of lean coal.

[0084] The distribution of random reflectance of vitrinite and the standard deviation of random reflectance of vitrinite of lean coal 1 are shown in Table 9.

[0085] Table 9 Lean coal 1

[0086]

[0087] The standard deviation of random reflectance of vitrinite of lean coal 1 is S = 0.093, the proportion of the minimum value of random reflectance of vitrinite plus 0.6 (1.30 + 0.6) is b = 0, DH S =-1.03(-1.07<DH S <-1.02) belongs to Class I mixed coal. It is recommended that the proportion of lean coal 1 used in coal blending and coking be controlled at 10%.

[0088] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for determining the blending grade of coking coal, characterized in that: According to different types of coking coal, the proportion of vitrinite random reflectance distribution in a certain interval is combined with the standard deviation of vitrinite random reflectance to calculate the coking coal blending grade index and judge the coking coal blending grade.

2. A method for determining the blending grade of coking coal according to claim 1, characterized in that: The coking coal is classified into weakly sticky coal, 1 / 2 medium sticky coal, gas coal, gas fat coal, 1 / 3 coking coal, fat coal, coking coal and lean coal, lean lean coal, and lean coal.

3. A method for determining the blending grade of coking coal according to claim 1, characterized in that: The method for determining the blending grade of weakly sticky coal, 1 / 2 medium sticky coal and gas coal is as follows: Calculate the coking coal blending grade index DH, DH Q =lg (s+a) +S, where: S is the standard deviation of vitrinite random reflectance, a is the proportion of vitrinite random reflectance distribution <0.5 interval; When DH Q When <-0.7, it is a single type of coal; When -0.7≤DH Q When <-0.57, it is mixed coal level I; When -0.57≤DH Q When <-0.5, it is mixed coal level II; When -0.5≤DH Q When <-0.4, it is mixed coal level III; When DH Q When ≥-0.4, it is mixed coal grade IV.

4. A method for determining the blending grade of coking coal according to claim 1, characterized in that: The method for determining the blending grade of gas fertilizer coal and 1 / 3 coking coal is as follows: Calculate the coking coal blending grade index DH, DH 1 / 3 =lg (s+b) ; Where: S is the standard deviation of the random reflectance of vitrinite, b is the percentage of the maximum value of the random reflectance of vitrinite minus 0.6; When DH 1 / 3 When ≤-1.07, it is a single type of coal; When -1.07<DH 1 / 3 When <-1.02, it is mixed coal level I; When -1.02≤DH 1 / 3 When <-0.92, it is mixed coal level II; When DH 1 / 3 When ≥-0.92, it is mixed coal grade III.

5. A method for determining the blending grade of coking coal according to claim 1, characterized in that: The method for determining the blending grade of fat coal is: Calculate the coking coal blending grade index DH, DH F =lg s -c; where: S is the standard deviation of the random reflectance of vitrinite, c is the proportion of 0.85 to 1.5 in the distribution of random reflectance of vitrinite; When DH F When ≤-2, it is a single type of coal; When -2<DH F When <-1.66, it is mixed coal level I; When -1.66≤DH F When <-1.15, it is mixed coal level II; When -1.15≤DH F When <-0.96, it is mixed coal level III; When DHF≥-0.96, it is mixed coal level IV.

6. A method for determining the blending grade of coking coal according to claim 1, characterized in that: The method for determining the blending grade of coking coal is: Calculate the coking coal blending grade index DH, DH J =lg s -c; where: S is the standard deviation of the random reflectance of vitrinite, and c is the proportion of vitrinite random reflectance distribution between 0.85 and 1.

5. When DH J When ≤-1.95, it is a single type of coal; When -1.95<DH J When <-1.05, it is mixed coal level I; When -1.05≤DH J When <-0.96, it is mixed coal level II; When -0.96≤DH J When <-0.89, it is mixed coal level III; When DH J When ≥-0.89, it is mixed coal grade IV.

7. A method for determining the blending grade of coking coal according to claim 1, characterized in that: The method for determining the blending grade of lean coal, lean lean coal and lean coal is as follows: Calculate the coking coal blending grade index DH, DH S =lg (s+b) ; S is the standard deviation of vitrinite random reflectance, b is the percentage of the minimum value of vitrinite random reflectance plus 0.6; When DH S When ≤-1.07, it is a single type of coal; When -1.07<DH S When <-1.02, it is mixed coal level I; When -1.02≤DH S When <-0.96, it is mixed coal level II; When -0.96≤DH S When <-0.89, it is mixed coal level II; When DH S When ≥-0.89, it is mixed coal grade III.

8. A method for determining the blending grade of coking coal according to any one of claims 1 to 7, characterized in that: During the coal blending process, coking coal of grades III and IV are eliminated based on the judgment results of the coking coal blending grade, the proportion of coking coal of grade II is 5% to 15%, and the proportion of coking coal of grade I is 8% to 20%, so as to stabilize the quality of coke.

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