JPH07244039A - Estimation of strength of coke - Google Patents

Abstract

PURPOSE:To certainly estimate the strength of coke with high accuracy by calculating the weighted mean of the characteristic evaluation index and average max. reflectivity calculated from the fluorescent spectrum characteristics of the compositional components at every raw material coal and the dispersion of the characteristic evaluation index and average max. reflectivity of coke raw material coal. CONSTITUTION:Fluorescent spectrum characteristics are measured under a constant condition at every compositional components of coal and a fluorescence relative intensity ratio I index at wavelengths of 800 and 550nm is calculated therefrom as a characteristic evaluation index. There is strong correlation between the weighted mean of the characteristic evaluation index and average max. reflectivity and coke strength and the calibration curve showing this correlation is preliminarily calculated experimentally. By using this calibration curve, coke strength can be accurately estimated. Further, the dispersion degree of the characteristic evaluation and the average max. reflectivity calculated at every coal to be compounded also correlates with coke strength. Therefore, by adding the dispersion of the characteristic evaluation index and the average max. reflectivity to calculation, the strength of coke can be estimated with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for highly accurately estimating the coke strength when a coke having a predetermined strength is produced by carbonizing the adjusted coal charged in a coke oven.

[0002]

2. Description of the Related Art In Japan, a wide variety of coals are imported, and these are appropriately blended to adjust the charging of coal to a coke oven. But the nature of this coal depends on its origin,
It depends on the coal mine, coal seam, etc.In order to produce stable quality coke from coal with different properties, it is necessary to use coking coal blending technology to produce coke of consistent quality at all times. It is necessary to adjust the charging charcoal.

Coke strength is one of the quality control items of coke. A huge amount of research has been conducted on the method of estimating the coke strength, and under certain conditions of carbonization, the coke strength cannot be estimated using the parameters representing the caking property of coal and the parameter representing the degree of coalification. It is a well-known fact. The parameter indicating the caking property is the maximum fluidity (MF) by the Gisellar fluidity test (JISM8801), and the parameter indicating the coalification degree is the average maximum reflectance of vitrinite (JISM881).
6) is often used.

However, when various kinds of coal are blended, the softening start temperature, the maximum fluidity temperature, and the solidification temperature are different due to the difference in the coal brand, so the MF of the plain brand is added to the MF estimation of the blended coal. When calculated as an average, it is very different from the MF of the actual blended coal, and it is difficult to accurately estimate the coke strength. For this reason, recently, Japanese Patent Laid-Open No.
As shown in -20592, the logarithmic value of the fluidity of the blended coal for each constant temperature between the softening start temperature and the solidification temperature is determined,
A method of calculating the fluidity of blended coal by weighted averaging the values and using the maximum value as the maximum fluidity of blended coal is being studied.

[0005]

In the conventional method as described above, the coal having no MF, such as non-coking coal and weathered coal, is handled in the same manner as other coals, and therefore the coke strength estimation accuracy is improved. However, there is a problem in that
In addition, it takes a long time to measure the MF, which requires a lot of manual work, which is troublesome, and the measurement accuracy is poor. Therefore, another new index management method is desired.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a coke strength estimating method that reliably and accurately estimates coke strength with less labor.

[0007]

A coke strength estimating method according to the present invention is a coke strength estimating method for producing a coke by mixing a plurality of types of raw material coal and carbonizing the mixture.
Along with determining the characteristic evaluation index by measuring the fluorescence spectrum characteristics of each tissue component for each raw coal, obtain the average maximum reflectance for each raw coal, the characteristic evaluation index for coke raw coal, the weighted average of the average maximum reflectance and The characteristic evaluation index and the variation in the average maximum reflectance are obtained, and the coke strength is estimated based on the weighted average and the variation.

[0008]

[Function] There is a strong correlation between the weighted average of the characterization index and the average maximum reflectance of the coke raw material coal and the coke strength. Therefore, the coke strength can be accurately estimated by previously obtaining a calibration curve representing the relationship between the characteristic evaluation index, the weighted average of the average maximum reflectance, and the coke strength by an experiment, and using this calibration curve. Furthermore, how much the characteristic evaluation index and average maximum reflectance required for each blended coal vary in the blended coke raw material coal is also correlated with the strength of the coke. Therefore, by adding the characteristic evaluation index and the variation in the average maximum reflectance to the calculation, it is possible to more accurately estimate the coke strength.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, the fluorescence spectrum characteristic is measured for each coal tissue component under a constant condition (excitation wavelength 450-490 nm, measurement field stop 0.63 mm, wavelength scanning step width 2 nm), and then the wavelength 800 nm and 55 are used as characteristic evaluation indexes.
I index, which is the ratio of the relative fluorescence intensities at 0 nm (I = I ₈₀₀ /
I ₅₅₀ ).

FIG. 1 is a graph showing the fluorescence spectrum characteristics for each coal texture component, where the horizontal axis is the wavelength (nM) and the vertical axis is the relative fluorescence intensity (%) at that time. The symbols in the figure represent the texture components of coal and are as follows. Ex: ecdinite, Sf: semi-fuginite, F: fujinitite, V: vitrinite As shown in FIG. 1, the fluorescence spectrum characteristics are remarkably different for each coal texture component, so that the I index is also different. Similarly, the I index differs depending on the brand of coal.

To obtain the Q index from the I index in consideration of the constituents of the coal, the following formula is used. Q = Σki · I (i) · Vi where I (i) is I of maceral i and Vi is maceral i.
The content rate of ki, ki, is an index obtained from multiple regressions by investigating the melting conditions of many coals in detail. In this embodiment, the Q index corresponds to the characteristic evaluation index described in the claims.

The average maximum reflectance of coal is JISM8816.
It measures based on. Using the above method, the weighted average of the Q index and average maximum reflectance of 10 brands of coal with different coal properties is calculated, and blended coals with different distributions are adjusted,
Coke was produced by dry distillation under constant conditions. Then, the strength of the dry-distilled coke was measured, and the relationship with each index was investigated.

FIG. 2 is a graph showing the relationship between the Q index value, the weighted average value of the average maximum reflectance and the coke strength, where the vertical axis is the coke strength (DI ³⁰ ₁₅ ) and the horizontal axis is the weighted average of the Q index value. Indicates a value. In the symbols in the figure, 4 is a weighted average value of average maximum reflectance, 1.20 is a weighted average value of average maximum reflectance, 6 is a weighted average value of average maximum reflectance, and 6 is a weighted average value of average maximum reflectance. Is a curve when is 1.00. As shown in the figure, when the weighted average value of the average maximum reflectance is constant, when the weighted average value of the Q index is extremely small or extremely large, the coke strength decreases.

Thus, the weighted average value of the Q index value and the average maximum reflectance is Ra, and the weighted average value of the Q index value is Q.
If a and coke strength are DI, the correlation between them is extremely strong, so the estimation formula of coke strength DI can be expressed as DI = f (Ra, Qa). Here, f is the function shown in FIG.

FIG. 3 is a graph showing the relationship between the Q index distribution value σ _Q which is the standard deviation of the Q index of blended coal and the coke strength. The vertical axis represents coke strength (DI ³⁰ ₁₅ ) and the horizontal axis represents Q.
Indicates the exponential distribution value σ _Q. The Q index distribution value is, for example, 10
When blending brands of coal, 10 Qs for each brand
This is the value obtained as the standard deviation of the index. Reference numeral 7 in the figure
Shows a curve when the average maximum reflectance is set to 1.10 and the Q index is set to 0.35. According to FIG. 3, even if the Q index is the same, the larger the distribution, the lower the coke strength.

FIG. 4 is a graph showing the relationship between the coke strength and the reflectance distribution σ _RO , which is the standard deviation of the average maximum reflectance of blended coal, and the vertical axis represents the coke strength (D
I ³⁰ ₁₅ ), the horizontal axis represents the reflectance distribution value σ _RO . The reflectance distribution value is a value obtained as a standard deviation of 10 average maximum reflectances for each brand when, for example, 10 brands of coal are blended. Reference numeral 8 in the figure has an average maximum reflectance of 1.1.
The curve when 0 and the Q index value are fixed to 0.35 is shown. It can be seen from FIG. 4 that the coke strength decreases as the distribution increases even if the reflectance is the same.

From the above, it was confirmed that the Q index value, the average maximum reflectance and the respective distribution values have a high degree of correlation with the coke strength. It was created. DI = f (Ra, Qa) + a * [sigma] _Q + b * [sigma] _RO + c (1) where a, b, and c are constants.

FIG. 5 shows a comparison between the coke strength estimation method using the equation (1) and the conventional coke strength estimation method. Figure 5
Is the average measured value 1 of the coke strength at the number of measurements every 5 days in the actual operation of coke production for 6 months,
The coke average strength value 2 estimated by the coke strength estimation method of the present invention for the same coke and the coke average strength value 3 estimated by the conventional coke strength estimation method are arranged on the same vertical axis. It is a list.

According to FIG. 5, the difference between the average measured value 1 of the coke strength and the average coke strength value 3 estimated by the conventional coke strength estimation method is 0.3. The difference variation from the coke average strength value 2 estimated by the coke strength estimation method of the present invention is 0.15, and the management variation is halved.

[0020]

EFFECT OF THE INVENTION According to the present invention, the fluorescence spectrum characteristic of each tissue component of the raw material coal is measured to obtain the characteristic evaluation index, and the average maximum reflectance for each raw material coal is obtained to evaluate the characteristics of the coke raw material coal. Index, average maximum reflectance weighted average and characterization index, average maximum reflectance variations are obtained, and coke strength is estimated based on these weighted averages and variations, so coke strength can be estimated with high accuracy. It will be possible.

[Brief description of drawings]

FIG. 1 is a graph showing fluorescence spectrum characteristics for each coal texture component.

FIG. 2 is a graph showing the relationship between Q index value, average maximum reflectance and coke strength.

FIG. 3 is a graph showing the relationship between the Q exponential distribution value and coke strength.

FIG. 4 is a graph showing the relationship between reflectance distribution values and coke strength.

FIG. 5 is a diagram showing a comparison between an average measured value of coke strength, an average estimated value according to the present invention, and an average estimated value according to a conventional method at the number of measurements every five days in actual operation.

[Explanation of symbols]

1 Measured value of coke strength 2 Coke strength value estimated by coke strength estimation method of the present invention 3 Coke strength value estimated by conventional coke strength estimation method 4 Average Curve 5 when maximum reflectance is 1.20 5 Average Curve when maximum reflectance is 1.10 6 Curve when average maximum reflectance is 1.00 7 Curve when average maximum reflectance is 1.10 and Q index value is constant at 0.35 8 Average maximum Curve with constant reflectivity of 1.10 and Q index value of 0.35 Ex Eczinit Sf Semi-Fujinit F Fujinit V Vitrinit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Fukada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd.

Claims (1)

[Claims] 1. In a method of estimating coke strength when coke is produced by mixing a plurality of types of raw material coal and carbonizing the mixture, the fluorescence spectrum characteristic of each tissue component is measured for each raw material coal to obtain a characteristic evaluation index. Along with, the average maximum reflectance is obtained for each raw material coal, the characteristic evaluation index for coke raw material coal, the weighted average and the characteristic evaluation index of the average maximum reflectance,
A coke strength estimation method characterized in that the coke strength is estimated based on the weighted average and the dispersion of the average maximum reflectance.