JP2000356633A - Method of measuring coke strength of coal, and manufacture of coke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make estimable the coke strength on the basis of the blending ratio of coal blend by evaluating the state of an aromatic condensed ring in a coal molecule about the constitution coal for the coal blend, and finding the relationship between the result of evaluation and the strength of coke after the carbonization of the coal blend. SOLUTION: The spectrum by a laser Raman spectroscopic analyzing method is measured on original coal of each brand composing coal blend, and for example, the characteristic value of G band peak or D band peak is found on each material coal on the basis of the spectrum. Plural kinds of coal blends different in kinds of brand of coal and/or a blending ratio, are prepared, and a Raman half value width of each coal blend is calculated on the basis of a half value width of each brand. Each coal blend is carbonized to produce coke, and the strength of each coke is measured. The correlation is found on the basis of the Raman half width of each coal blend and the strength of coke by plotting and the like. The strength of coke after the carbonization can be accurately estimated on the basis of only a blending ratio on the remarked coal blend by using the correlation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a blend of non-caking coal and finely-coking coal (non-coking coal) and non-fluid or low-fluid coal such as weathered coal. The present invention relates to a method of measuring the quality of coal, particularly the strength of coke after carbonization, in a technique of manufacturing coke for steelmaking to obtain coke of a predetermined quality. The present invention also relates to a method for producing coke using this measuring method.

[0002]

2. Description of the Related Art In the production of coke required for iron making in a blast furnace, a particularly important quality control item is the strength of coke. If the coke strength is improved, the blast furnace operation can be performed stably. If a large amount of expensive strong caking coal is added, coke strength is improved, but coke production cost is increased. On the other hand, if the proportion of the inexpensive non-slightly caking coal is increased, the cost is reduced, but the coke strength is reduced.

[0003] By the way, currently coke is generally produced by blending dozens of types of coal. In manufacturing, it is important to prevent variation in coke quality (particularly strength). If there is a variation in strength or the like, expensive coking coal is added in a large amount in consideration of the safety factor with respect to the coke strength target required for the blast furnace, and the production cost increases. In order to reduce the variation in coke strength, it is ideally desirable to always keep the brand ratio of coal at the time of blending the same. However, it is difficult to operate coal at a constant blending brand and proportion in terms of coal supply and demand. Therefore, coal quality (properties) is evaluated in advance by analysis, and when switching brands, brands having similar coal quality are used. Alternatively, a method has been adopted in which a correlation between coal quality and coke strength is examined, and when the brand is switched, this correlation is used to determine a blended brand and a blending ratio.

In estimating the coke strength using the correlation, for example, parameters related to coal properties, such as a coalification parameter, a caking property parameter, and an inert component parameter of the coal to be blended, are measured and combined. Is done. These parameters are generally evaluated as follows. That is, coal degree parameter is evaluated by the average reflectance of the vitrinite representing the maturity of coal (R _O). The caking parameters are evaluated in terms of the Giesser maximum flow (MF), which describes the softening and melting properties of the coal. The inert component parameter is evaluated by the total inert (TI) amount obtained from the coal structure analysis.

[0005] Among them, the average reflectance of vitrinite representing the maturity of coal (R _O) is measured using a polarizing microscope. Methods for measuring such an average reflectance (R _O) is strong there is no problem in measuring the like coking coal, when intended for non-slightly-caking coal, the measurements at low coalification degree area Accuracy decreases. That is, it is impossible to principle an accurate evaluation of coal, such as the average reflectance (R _O) the soft coking coal.

[0006] With the recent need for cost reduction, coke has often been produced by blending a large amount of inexpensive coal such as non-coking coal. Therefore, the average in a method of measuring the reflectance (R _O), there is a problem that it is difficult to accurately estimate the coke strength.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of measuring coke strength, which can accurately estimate the strength of coke, and a method of producing coke using this method. .

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide, for each coal (coking coal) of a blended coal, the structural state of an aromatic fused ring constituting a coal molecule. In particular, information on the expansion of the aromatic condensed ring, or information on the skeleton structure of the coal molecule after the heat treatment, particularly on distortion such as torsion is obtained. These information about the coking coal reflects the coal properties parameters of the coking coal. By using the relationship between these pieces of information and the coke strength, the coke strength can be accurately estimated from the blending ratio, and the blending management for coke production can be facilitated. Information on the structural state of the fused aromatic ring or the skeleton structure after heat treatment can be obtained by laser Raman spectroscopy or solid ¹³ C-
It can be obtained using nuclear magnetic resonance measurement.

That is, according to the present invention, the state of the aromatic condensed ring in the coal molecule is evaluated for at least one of the raw coals constituting the blended coal, and the evaluation result and the coke strength after the blended coal is carbonized. And measuring the coke strength of the blended coal from the blending ratio using the relationship.

Further, according to the present invention, the skeleton structure of at least one of the raw coals constituting the coal blend after heat treatment is evaluated, and the relationship between the evaluation result and the coke strength after carbonization of the coal blend is evaluated. A method for measuring the coke strength is provided, wherein the coke strength of the blended coal is estimated from the blending ratio by using the obtained relationship.

In the present invention, the evaluation of the raw coal is preferably performed by using the characteristic values of peaks obtained by laser Raman spectroscopy.

In the present invention, it is preferable to use a characteristic value for a G or D band peak as the peak characteristic value.

Further, in the present invention, the state of the aromatic condensed ring is preferably evaluated using characteristic values of a spectrum obtained by a solid-state ¹³ C-nuclear magnetic resonance method.

In the present invention, the state of the aromatic condensed ring is preferably evaluated by using the degree of aromatic ring condensation obtained from the characteristic value of the spectrum of solid-state ¹³ C-nuclear magnetic resonance.

According to the present invention, (a) the step of evaluating the state of the aromatic condensed ring in the coal molecule or the skeleton structure after the heat treatment of the raw coal; and (b) the raw material using the above-mentioned evaluation results. (C) a step of blending the selected raw coal to produce a blended coal, and (d) a step of carbonizing the blended coal to produce coke. A manufacturing method is provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, an evaluation method by laser Raman spectroscopy will be described, and then, an evaluation method by solid-state ¹³ C-NMR will be described.

<Evaluation method by laser Raman spectroscopy
Method> The present inventors have studied laser Raman for various coals.
Measure the spectrum to investigate and study the molecular structure of coal.
Was. As a result, the peak characteristics of the laser Raman spectrum
Sex value, for example, the half-value width varies depending on the type of coal
Instead, it reflects the structure of the coal molecule.
are doing. The peak is 1600 cm ^-1Near
G band peak located or wave number 1400cm^-1Attached
The nearby D band peak is used. G band peak
Is a carbon double bond, sp^TwoCoal due to coal
Aromatic condensation in coal molecules derived from the graphite structure of
Represents the nature of the ring skeletal structure. The D band peak is
It came from the disordered structure of coal,
Found to provide information about the structure of coal molecules
are doing.

The narrower the full width at half maximum of these peaks, the higher the integrity of the skeletal structure. For example, when measured for coal before heat treatment, the spread of aromatic condensed rings is larger as the half width is smaller, and when measured for coal after heat treatment at a predetermined temperature as described later, The smaller the value range, the smaller the distortion such as the torsion of the skeletal structure. It has been found that when coal having high skeleton structure integrity is blended, the coke strength obtained by carbonizing the blended coal is improved even if the coal is non-caking coal. As described above, there is a correlation between the half width of the peak and the coke intensity after carbonization, and if this relationship is used, the coke intensity can be accurately estimated from the blending ratio thereafter. Hereinafter, the evaluation procedure will be specifically described.

(1) First, the spectrum of each brand coal (raw coal) constituting the coal blend is measured by laser Raman spectroscopy. The laser Raman spectrum can be obtained by a commercially available spectroscope. The type of laser is not particularly limited,
An Ar laser, a He-Ne laser, or the like can be used.

FIG. 1 shows an example of a laser Raman spectrum.
Is shown. The horizontal axis in FIG. 1 is the wave number (cm) of the laser.^-1)
The vertical axis represents the Raman intensity. As shown in Figure 1, llama
Spectrum is 1600 cm wave number^-1G band around
And wave number 1400cm ^-1Near D band peak
including.

As described above, the spectrum is measured without or after heating the coal. The coke strength can be more accurately estimated by using the spectrum measured for the heated coal than the spectrum measured for the unheated coal. The heating temperature is in the vicinity of the solidification temperature at which the coal melts and then solidifies, for example, about 5 ° C.
00 ° C. or the dry distillation temperature of coal, for example, about 1100 ° C.
Is preferred. The spectrum is measured by heating the coal at either temperature, or by heating the coal at both temperatures. When measuring at either temperature,
It is preferable to measure at the carbonization temperature because the accuracy of strength estimation is higher. When measuring at both temperatures, for example, the coal is divided into two or more groups, one group is heated at the solidification temperature, and the other group is heated at the carbonization temperature, and each spectrum is measured. Then, as described in the next procedure, the difference between the half-value widths obtained from the respective spectra is obtained and used thereafter.

(2) From the laser Raman spectrum obtained in step (1), for each brand of coal, for example, G
A characteristic value of the band peak or the D band peak is obtained.
The characteristic values of these peaks are, for example, the half widths of the peaks, and can be obtained as follows. That is, as shown in FIG. 1, after the shape of the band peak is defined by the baseline defining the bottom line of the peak, this peak is extracted from the spectrum. These operations can be performed by signal processing of measurement data and the like.

FIG. 2 shows an example of the extracted G band peak. The peak width (a shown in FIG. 2) at half the peak intensity (height) shown in FIG. 2 is the half width. Note that the method of obtaining the half width is not limited to the above method. For example, after determining the shape of the band peak using a computer or the like, the band peak may be obtained by performing peak division by curve fitting using the least squares method, and the half width may be obtained from the obtained peak. Using the half widths of the individual brands thus determined, the Raman half width of the blended coal is determined in the following procedure (3).

As described above, when coal of the same brand is heated at two temperatures and the spectrum is measured for each of them in the procedure (1), the half width is determined for each spectrum, and the difference between these half widths is determined. Is calculated. Then, the difference between the half widths is used as the value of the half width of the brand in the next procedure (3).

(3) A plurality of blended coals having different types and / or blending ratios of coal brands are produced. The Raman half-value width of each blended coal can be calculated by adding the half-value widths of individual brands determined in step (2) according to the following equation (1).

ΔH _1/2 (coal blended coal) = iW _i ΔH _{1/2 i} (1) where ΔH _1/2 (coal blended coal) is blended coal a Raman half-value width, W _i is the proportion of coal i stocks (rate), delta
H _{1/2 i} is the Raman half value width of the i brand. Thus, in the present invention, the Raman half-width of the blended coal can be determined from the half-width of each brand of coal without directly measuring the Raman spectrum.

(4) Next, each blended coal prepared in the procedure (3) is carbonized to produce coke, and the strength of each coke is measured. The strength measurement is performed, for example, according to JISK2
The measurement is performed according to the drum strength measurement shown in FIG.

(5) From the Raman half width ΔH _1/2 (coal blend) of each blended coal determined in step (3) and the strength of each coke measured in step (4), the Raman half width and coke strength are determined. Is obtained by drawing or the like.

(6) By using the correlation obtained in step (5), the coke strength after dry distillation can be accurately estimated only from the blending ratio of the blended coal of interest. That is, the Raman half-width of the blended coal is calculated from the blending ratio and the Raman half-width of each brand of coal obtained in the procedure (1) according to the above equation (1). Then, from the calculated half width of the blended coal, the strength of the coke after carbonization can be accurately estimated based on the correlation obtained in step (5).

<Evaluation Method by Solid-State ¹³ C-NMR> The present inventors measured solid-state ¹³ C-NMR (nuclear magnetic resonance) spectra of various coals, and investigated the molecular structure of the coals.
investigated. As a result, it has been found that the intensity of the solid-state ¹³ C-NMR spectrum varies depending on the type (brand) of coal, and reflects the molecular structure. In particular, for example, among the peaks derived from aromatic carbon at around 127 ppm when the peaks are split (peak 6 in FIG. 3), the intensity of the slow-decaying component is derived from the internal quaternary carbon number, Indicates the nature of the skeleton structure of the fused ring. It has been found that as the ratio of the number of internal quaternary carbon atoms to the total aromatic carbons, that is, the degree of aromatic ring condensation χb ^' , increases, the spread of the aromatic fused rings increases and the integrity of the skeleton structure increases. And it has been found that, when coal having a high skeleton structure integrity is blended among non-coking coals, coke strength obtained by carbonizing the blended coal is improved.

(1) First, the NMR of ¹³ C, which is an isotope of a carbon atom, of each brand of coal constituting the blended coal.
(Nuclear magnetic resonance) absorption spectrum is measured. The NMR measurement may be performed according to a usual method. The measurement is
The process may be performed on a vitrinite component obtained by separating coal by specific gravity or the like, or may be directly performed on unseparated coal.

FIG. 3 shows the NMR obtained for solid ¹³ C.
1 shows an example of a spectrum. As shown in FIG. 3, the solid ¹³ C
Is roughly divided into aromatic carbon and aliphatic carbon, and has a peak mainly at around 130 ppm and 30 ppm, respectively. The spectrum shown in FIG. 3 is obtained when the delay time τ is 0 μs. The delay time τ is the time from when the radio pulse is cut to when the measurement starts.

(2) Next, the degree of aromatic ring condensation χ ^{b '} is determined for each brand of coal from the ¹³ C NMR spectrum measured in the procedure (1). χb ^′ is the ratio of the number of internal quaternary carbons to the number of total aromatic carbons in the coal molecule. The internal quaternary carbon is a carbon surrounded by an aromatic ring as shown in FIG. χ ^{b '} is obtained as follows.

(I) First, of the spectra shown in FIG. 3, a spectrum between about 200 ppm and about 90 ppm is decomposed into peaks 1 to 7 as shown in FIG. 3 by curve fitting or the like. Peaks 1 and 2 are peaks attributed to aliphatic carbon in the coal molecule, and peaks 3 to
7 is a peak due to aromatic carbon.

(Ii) The area of a portion of 135 ppm or less of peak 6 in FIG. 3 and 90 ppm or more, for example (shaded portion in FIG. 3) is obtained, and the ratio α to the total area of peaks 3 to 7 is calculated by the following equation (2). Calculated according to

Α = (Area ′ ₆ ) / (Area _3-7 ) (2) where Area ′ ₆ is the area of the hatched portion of peak 6, and Area _3-7 is the total area of peaks 3 to 7. Ar
ea _3-7 indicates the total number of aromatic carbon atoms, and Area ′ ₆ indicates the number of aromatic carbon atoms of only the chemical formulas (A) and (B) in FIG.
That is, the area ratio α indicates the ratio of the number of aromatic carbon atoms of only the chemical formulas (A) and (B) in FIG. 4 to the total number of aromatic carbon atoms.

(Iii) A spectrum as shown in FIG.
The measurement is performed for each delay time τ while changing to 0 stages.
In each measured spectrum, the height of peak 6 was determined,
The relationship between the height of the peak 6 and the delay time τ is plotted.

FIG. 5 shows an example of the relationship between the height of the peak 6 thus plotted and the delay time τ. The horizontal axis in FIG. 5 is the delay time τ (μs), and the vertical axis is the height M of the peak 6.
This is the logarithmic value Log (M (τ)) of (τ). As shown in FIG. 5, the height M (τ) of the peak 6 attenuates with the delay time τ.

M (τ) shown in FIG. 5 is converted into two waveforms M ₁ by least square fitting according to the following equation (3).
(Τ) and M ₂ (τ).

M (τ) = M₁(Τ) + M_Two(Τ) = M_OSexp (−τ / T_2S) + M_OFexp [−0.5 (τ / T_2F)^Two] (3) FIG. 5 shows these divided components M₁(Τ) and M
_Two(Τ) is also shown. M₁(Τ) is the slow-decay component of peak 6.
And is due to the aromatic carbon of formula (B) in FIG.
You. M_OSIs the initial intensity of this component and M₁(Τ) vertical
Intersection with axis (M₁(Τ) at τ = 0).
T_2SIs the relaxation constant (μs) of this component, and M ₁(Τ)
Is the reciprocal of the slope of. On the other hand, M
_Two(Τ) is the fast-decay component of peak 6, which is shown in FIG.
It is caused by the aromatic carbon of the formula (A). M_OFIs the component
Initial strength, M_TwoIntercept (M) that intersects the vertical axis of (τ)_Two
(Τ) at τ = 0). T_2FReduces this component
Constant (μs), τ^Two-Log (M_Two(τ))
M_TwoThe inverse of the slope of (τ)
is there.

As can be seen from the above, M _OS and M _{OF in} FIG.
Respectively form part of the height M (τ) of the peak 6 at τ = 0. That is, M _OS + M _OF is equal to the height of the peak 6 in FIG.

(Iv) Next, the ratio β between M _OS and (M _OS + M _OF ) is obtained as in the following equation (4).

Β = M _OS / (M _OS + M _OF ) (4) β is the ratio of M _OS to the height of peak 6 in FIG. Show a match.

As described above, the intensity of the peak 6 shown in FIG.
The degree is M_OS+ M_OFbe equivalent to. And M _OFIs the chemical formula of FIG.
Due to the aromatic carbon of (A), M_OSIs the formula (B)
Due to aromatic carbon. Therefore, β according to the above equation (4) is
The fragrance of the chemical formula (B) in FIG. 4 among the shaded areas in FIG.
Shows the ratio of group carbon.

(V) By multiplying the ratio α obtained by the above equation (2) by the ratio β obtained by the above equation (4), the degree of aromatic ring condensation χ ^{b ′} is obtained by the following equation (5).

Χ ^{b ′} = α × β ……………………………………… (5) As described above, the ratio α in FIG. The ratio of the number of aromatic carbon atoms in Chemical Formulas (A) and (B) is shown in the total number of aromatic carbon atoms. The ratio β indicates the ratio of the number of aromatic carbon atoms in the chemical formula (B) to the number of aromatic carbon atoms in the chemical formulas (A) and (B). Therefore, χ ^{b ′} obtained by multiplying the ratio α and β is as shown in FIG.
Shows the ratio of the number of aromatic carbon atoms of the chemical formula (B) to the total number of aromatic carbon atoms in the above formula. The aromatic carbon of the chemical formula (B) is a carbon surrounded by an aromatic ring. That is, χ ^{b ′} indicates the ratio of the number of internal quaternary carbons to the number of total aromatic carbons in the coal molecule. Thus, the degree of aromatic ring condensation χb ^′ can be determined for each brand of coal by the above procedures (i) to (v).

[0047] As a method for obtaining the aromatic ring condensation degree chi ^{b ',} in addition to the above-described method, using the ¹³ CNMR, for example Mark S. Solum et al. (Energy)
& Fuels, 1989, 3, 187). At this time, the measurement conditions and peak splitting method for obtaining 際^{b '} are not particularly limited, and any method may be used as long as the method can quantitatively obtain the total aromatic carbon and internal quaternary carbon.

(3) Next, a plurality of blended coals having different coal brands and / or blending ratios are produced. Χ ^{b 'of} each coal blend
Can be calculated from に 従 っ_て ^{b ′} _i of each stock obtained in step (2) by adding them according to the following equation (4).

Χ ^{b '} (blended coal) = ΣW _i χ ^b' _i ………………………………… (4) where χ ^{b '} (blended coal) is blended coal Is the degree of aromatic ring condensation χ ^{b ′} , W _i is the blending ratio (ratio) of i brands, and χ ^{b ′} _i is i
Χ ^{b '} of the brand. As described above, in the present invention, χb ^{'of the} blended coal can be determined from χb ^' of each coal without directly determining by NMR measurement.

(4) Next, coking is produced by dry-distilling each of the coal blends prepared in step (3), and the coke strength of each coke is measured. The intensity measurement is, for example, J
The measurement is performed in accordance with the drum strength measurement described in ISK2151.

(5) χ ^{b ′ of} each coal blend determined in step (3)
From the (coal blended) and the strength of each coke measured in step (4), the correlation between χb ^' and the coke strength is determined by drawing or the like.

(6) Using the correlation obtained in (5),
After that, for the blended coal of interest,
Can accurately estimate the coke strength before carbonization.
You. In other words, the mixing ratio and the individual brands determined in step (2)
Pattern of coal^{b '}From the formula (4) above,
^{b '}(Blended coal) is calculated. And the calculated blended coal χ
^{b '}(Coal blend), based on the correlation determined in step (5)
To accurately estimate the strength of coke after carbonization.
Wear.

If coke is produced based on the measurement results of the present invention for each raw coal, the cost of producing coke can be reduced. Specifically, the skeleton structure of the aromatic condensed ring is evaluated for the raw coal, the raw coal is selected using the evaluation results, and a blended coal is prepared from the selected raw coal and carbonized to produce coke. With the present invention,
Since the strength of coke after production can be accurately estimated, it is not necessary to mix a small amount of non-coking coal of non-coking coal in consideration of the safety factor in order to secure the required strength. Therefore, a large amount of non-coking coal can be used as compared with the conventional method, and the production cost of coke is reduced.

In addition to applying the measuring method of the present invention to raw coal after purchasing from a supplier, applying the measuring method of the present invention to raw coal before purchasing from a supplier, The coking coal may be sorted first.

[0055]

EXAMPLES Example 1 Five brands (non-coking coals) of five brands (charcoal A to coal E) were mixed with base coking coal of coking coal to produce a plurality of coking coals, Was made from the coke.
Then, a correlation between the laser Raman G band half width and the coke strength of each blended coal was determined.

First, the Raman G band half-width was measured for each brand of non-coking coal as follows. Each coal is crushed under 1 mm, embedded in epoxy resin, molded, polished by a usual method,
The sample was used for Raman spectrum measurement. Using an NR-2000 type laser Raman spectrophotometer manufactured by JASCO Corporation, an Ar ion laser (wavelength: 514.5 nm, laser power: 0.1 mW, laser spot diameter: 40 μm)
m) gave a spectrum derived from vitrinite in coal.

Table 1 below shows the Raman G band half width measured for each of the non-coking coals A to E.

[0058]

[Table 1]

Next, four brands of caking coal (charcoal a to charcoal d)
Were blended at the ratios of 15, 32, 23, and 30% by weight, respectively, to prepare a base blended coal of caking coal. Then, for each of the caking coal and the base blended coal, the Raman half width was measured in the same manner as in the case of the non-fine caking coal described above.

Table 2 below shows the values of the Raman G band half-value width measured for each of the coking coals a to d and the Raman G band half value of the base blended coal.

[0061]

[Table 2]

The Raman G band half width of the base blended coal in Table 2 above is a value calculated according to the above formula (1) from the half width measured for each of the caking coals of coals a to d. .

Next, 5 ca.
Alternatively, a plurality of blended coals were prepared by blending 10% by weight of non-coking coals A to E. Then, a can baking test was performed for each blended coal. That is, furnace temperature 1100 °
After 7 hours of carbonization in a coke oven, the mixture was taken out of the oven and sprinkled to extinguish the fire. The packing density of blended coal is 0.8
T / m ³ . After making coke in this way, J
Coke drum strength (DI ³⁰ ₁₅ ) was measured according to IS.

Table 3 below shows the value of the Raman G band half-width for each blended coal and the drum strength of coke produced from each blended coal.

[0065]

[Table 3]

In Table 3 above, the value of the half-width of the Raman G band for each blended coal is the half-width value of the coals A to E shown in Table 1 and the half-width of the base blended coal shown in Table 2. Is a value calculated according to the above formula (1) using the blending ratio from the value of.

Comparative Example 1 Charcoal A to E prepared in Example 1
For each of non-coking coal of coal, coking coal of coal a to coal d, base blended coal prepared from these caking coals, and blended coal obtained by mixing non-fine caking coal and base blended coal, was measured average reflectance (R _O). Then, the correlation between the average reflectance of each coal blend and the coke strength was determined. Table 1 above
3 shows the measured value of R _O. Table 1 and Table 2
Shows the other property parameters (MF, TI) of coal measured according to JIS, and the ash value.

FIG. 6 shows the correlation between the Raman G band half width and the average reflectance of each blended coal measured in Example 1 and Comparative Example 1 and the coke strength of each blended coal.
The horizontal axis in FIG. 6 is a coke strength D ³⁰ ₁₅ of each coal blend, the left vertical axis Raman G band half-width of the coal blend, and the right vertical axis is the R _O of the coal blend. As is clear from FIG.
There is a better correlation between the Raman G band half width and the coke intensity according to the present embodiment. It is clear that the coke strength can be estimated with high accuracy by using this correlation, confirming the effect of the present invention. Also, a good correlation is established for the base blended coal consisting only of caking coal (the measurement point where the value of the coke strength is the largest in FIG. 6). From this, the method of measuring the coke strength using the Raman half-width according to the present invention is effective not only for the case of blending non-fine caking coal, but also for the case of blending coal in the conventional caking coal region. You can see that.

Example 2 A plurality of blended coals were prepared by mixing five brands (F coal to J coal) of non-fine caking coal with a base coal blend of caking coal. Coke was made. Each of the coal blends was heat-treated at two temperatures to obtain a difference in Raman G band half width (ΔG band half width), and a correlation between the difference in half width and coke strength was obtained.

First, the Raman half width was measured as follows for each brand of non-coking coal. After the coal of each brand was pulverized into 60 mesh under and divided into two groups, each group of each brand was loaded into a test tube having an inner diameter of 5 mm so that the packing density was the same. One group of each brand was naturally cooled immediately after the temperature was raised from room temperature to 500 ° C. at a rate of 3 ° C./min. The other group is from room temperature to 1100 ° C at a heating rate of 3 ° C / min.
After the temperature was raised to, the temperature was immediately cooled. After taking out the heat-treated sample of each group and embedding it in epoxy resin, etc.
A measurement sample was prepared in the same manner as in Example 1, and the Raman spectrum was measured to determine the G band half-value width. And
From the G band half width of the sample heat treated at 1100 ° C.
Subtract the G band half-value width of the sample heat treated at 0 ° C. to obtain ΔG
The band half width was determined.

Table 4 below shows the Raman ΔG band half width measured for each of the non-coking coals F to J.

[0072]

[Table 4]

Next, 20% by weight was added to the base blended coal of caking coal.
A plurality of blended coals were prepared by blending each of non-coking coals of coals F to J. Example 1 for each coal blend
Coke was prepared in the same manner as described above, and the coke drum strength (DI ³⁰ ₁₅ ) was measured.

Table 5 below shows the ΔG band half width for each blended coal and the drum strength of the coke produced from each blended coal.

[0075]

[Table 5]

In Table 5 above, the value of the ΔG band half width for each blended coal is shown in Table 4 by
G-band half-width value and ΔG of base blended coal shown in Table 5
From the value of the band half width, the formula (1)
Is a value calculated according to

FIG. 7 shows the Δ of each blended coal measured in Example 2.
4 shows a correlation between G-band half-width and coke intensity. The horizontal axis in FIG. 7 is the ΔG band half width of each blended coal,
The vertical axis is the coke strength of each blended coal. As is clear from FIG. 7, a good correlation is established between the ΔG band half-value width and the coke intensity, and it is apparent that the coke intensity can be estimated with high accuracy using this correlation. The effect was confirmed.

Example 3 Five brands (K coal to O coal) of non-fine caking coal were mixed with caking coal base blend coal to produce a plurality of coal blends, and from each blend coal, Coke was made. Then, the correlation between the laser Raman D-band half width and the coke strength of each blended coal was determined.

First, the measurement was made as follows for each brand of non-coking coal. Each coal was pulverized to a mesh under 60 and then charged into a test tube having an inner diameter of 5 mm so that the packing density was the same. And, the heating rate 3
After the temperature was raised to 1100 ° C. at a rate of ° C./min, it was immediately cooled.
After removing the heat-treated sample, a measurement sample was prepared in the same manner as in Example 1, and the Raman spectrum was measured.
The band half width was determined.

Table 6 below shows the Raman D band half width measured for each of the non-coking coals K to O.

[0081]

[Table 6]

Next, 5 or 20% by weight of non-fine caking coals of K coal to O charcoal were blended with the base coal blend of caking coal to prepare a plurality of coal blends. Then, coke was prepared for each coal blend in the same manner as in Example 1, and the coke drum strength (DI ³⁰ ₁₅ ) was measured.

Table 7 below shows the value of the D-band half width for each blended coal and the drum strength of coke produced from each blended coal.

[0084]

[Table 7]

In Table 7 above, the value of the D-band half-width for each coal blend is shown in Table 6 by the values of the D-band half-widths of K coal to O coal and the D-band of the base coal blend shown in Table 7. It is a value calculated from the value of the half-value width according to the above formula (1) using the blending ratio.

FIG. 8 shows the D of each coal blend measured in Example 3.
4 shows a correlation between band half-width and coke intensity.
The horizontal axis in FIG. 8 is the D-band half width of each blended coal, and the vertical axis is the coke strength of each blended coal. As is apparent from FIG. 8, it is clear that a good correlation is established between the D-band half-width and the coke intensity, and that the coke intensity can be estimated with high accuracy using this correlation. (Example 4) Five brands (P coal to T coal) of non-coking coal were mixed with a base coal of caking coal to produce a plurality of coal blends. Was made from the coke. Then, a correlation between the degree of aromatic ring condensation (χ ^{b ′} ) of each coal blend and the coke strength was determined.

First, the following measurement was performed on coal of each brand of non-coking coal. Each coal was separated by a method such as specific gravity separation, and the vitrinite component was extracted. Then, this was pulverized to a mesh size of less than 60 to obtain a sample for solid-state ¹³ C-NMR measurement. GX-270 ( ^13C frequency 67.8 MHz) manufactured by JEOL Ltd. for solid-state ¹³ C-NMR measurement.
Was used. Further, the rotation frequency was set to 5 kHz, and the number of times of integration of the measurement was set to a sufficiently large value.

Table 8 below shows the degree of aromatic ring condensation (χ ^{b ′} ) measured for each of the non-coking coals P to T.

[0089]

[Table 8]

Next, four brands of caking coal (e-coal)
Was blended at a ratio of 15, 30, 23, and 32% by weight, respectively, to prepare a base blended coal of caking coal. Then, for each of the caking coal and the base blended coal, the degree of aromatic ring condensation (χ ^{b ′} ) was measured in the same manner as in the case of the non-fine caking coal described above.

[0091] The following table 9 shows ^'and, based coal blend of the aromatic ring condensation degree (chi ^b e coal ~h charcoal aromatic ring condensation degree was determined for each viscosity coals (chi ^b)' the value of).

[0092]

[Table 9]

The degree of aromatic ring condensation (χb ^' ) of the base blended coal in Table 9 above is calculated from the value of χb ^' measured for each of the caking coals e to h in accordance with the above equation (4). This is a calculated value.

[0094] Next, 5
Or 10% by weight of non-coking coal of P coal to T coal
By blending, a plurality of coal blends were produced. And each blended coal
A coke was prepared in the same manner as in Example 1 for
Coke drum strength (DI³⁰ ₁₅) Was measured.

Table 10 below shows the value of the degree of aromatic ring condensation (χ ^b ) for each blended coal and the strength of coke produced from each blended coal.

[0096]

[Table 10]

In Table 10 above, the value of the degree of aromatic ring condensation (χ ^{b ′} ) for each blended coal is shown in Table 8 below.
A value calculated from the value of the degree of aromatic ring condensation (χ ^{b '} ) of the charcoal and the value of the degree of aromatic ring condensation (χ ^b' ) of the base blended coal shown in Table 9 using the blending ratio in accordance with the above formula (4). It is.

Comparative Example 2 P coal to T prepared in Example 4
For each of non-coking coal of coal, coking coal of e-h coal, base blended coal prepared from these caking coals, and blended coal of non-fine caking coal and base blended coal, was measured average reflectance (R _O). Then, the correlation between the average reflectance of each coal blend and the coke strength was determined. Table 8 above
10 shows the measured value of R _O. Tables 8 and 9 also show other property parameters (MF, TI) and ash content of the coal measured according to JIS.

FIG. 9 shows the relationship between the degree of aromatic ring condensation (χ ^{b ′} ) and the average reflectance (R _O ) of each blended coal measured in Example 4 and Comparative Example 2 and the coke strength of each blended coal. The correlation is shown. The horizontal axis of FIG. 9 indicates the coke strength D ³⁰ ₁₅ of each blended coal.
, And the vertical axis on the left side aromatic ring condensation degree of each coal blend (chi ^{b '),} the vertical axis represents the average reflectance of each coal blend the right (R _O)
It is. As is apparent from FIG. 9, there is a better correlation between the degree of aromatic ring condensation (χ ^{b ′} ) and coke strength according to the present invention. It is clear that the coke strength can be estimated with high accuracy by using this correlation, confirming the effect of the present invention. Also, a good correlation is established for the base blended coal consisting only of caking coal (the measurement point where the value of the coke strength is the largest in FIG. 9). From this, the method for measuring the coke strength using the degree of aromatic condensation according to the present invention is effective not only for the case where non-fine caking coal is blended but also for the case where coal in the conventional caking coal region is blended. You can see that there is.

Example 5 The economic effect of the coke strength measuring method of the present invention was evaluated. Specifically, the production cost when producing coke having a drum strength of 90 or more from a coal blend consisting of caking coal and non-fine caking coal was evaluated.

Tables 11 and 12 below show blended coal prices and estimated drum strengths for blended coal obtained by mixing a commercially available base coal of caking coal with a commercially available non-fine caking coal (charcoal X or coal Y). Is a typical value. Blended coal price is calculated from the price of each coking coal. The estimated value of the drum strength is an estimated value based on a conventional estimation formula using R ₀ or the like or an estimation formula using the Raman half width or the degree of aromatic condensation according to the present invention.

[0102]

[Table 11]

[0103]

[Table 12]

As shown in FIGS. 6 and 9, the accuracy of estimating the drum strength is as low as about ± 3 in the conventional measuring method. Therefore, in order to guarantee a drum strength of 90 or more, coke having a drum strength estimated value of 93 or more must be produced. On the other hand, as shown in FIGS.
In the measuring method of the present invention, the estimation accuracy is as high as about ± 1. Therefore, in order to guarantee a drum strength of 90 or more, coke having a drum strength estimated value of 91 or more may be manufactured.

Therefore, as is apparent from Table 11 above, when the present invention is used, coke is produced using a blended coal (blended coal number 3 in Table 11) containing a cheaper raw material (non-coking coal Y). You can see what you can do. Further, as is clear from Table 12, it is also understood that coke can be produced using a blended coal (blended coal number 3 in Table 12) containing a larger amount (20% blended) of a cheaper raw material (non-coking coal Y). . As described above, it is apparent that the use of the measuring method of the present invention can reduce the cost of producing coke.

[0106]

As described above in detail, according to the present invention, it is possible to accurately evaluate the properties of a wide variety of coals including non-slightly caking coal, to improve the coal evaluation accuracy, and to improve the coke strength. The accuracy of estimation can be improved. Therefore, it is not necessary to mix a small amount of non-coking coal in anticipation of the safety factor in order to secure the coke strength. As a result, there is also an economic effect of reducing coke production costs.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a laser Raman spectrum of coal according to the present invention.

FIG. 2 is a diagram showing an example of a method for obtaining a Raman half-width of a laser Raman spectrum according to the present invention.

FIG. 3 is a diagram showing an example of a solid-state ¹³ C-NMR spectrum and peak splitting of the coal according to the present invention.

FIG. 4 is a diagram showing chemical formulas of some aromatics derived from a solid-state ¹³ C-NMR peak according to the present invention.

FIG. 5 is a diagram showing an example of a change in the intensity of the peak around 127 ppm with respect to the delay time of the solid-state ¹³ C-NMR spectrum of the coal according to the present invention.

FIG. 6 is a diagram showing the relationship between the Raman G band half-width and average reflectance obtained in Example 1 and Comparative Example 1 and coke drum strength.

FIG. 7 is a diagram showing the relationship between the Raman ΔG band half-width obtained in Example 2 and coke drum strength.

FIG. 8 is a diagram showing a relationship between Raman D band half width obtained in Example 3 and coke drum strength.

FIG. 9 is a view showing the relationship between the degree of aromatic ring condensation and the average reflectance obtained in Example 4 and Comparative Example 2 and coke drum strength.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G01N 24/08 510S (72) Inventor Kiyoshi Fukada 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Tube Stock Inside the company (72) Inventor Shozo Itagaki 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Inside Kokan Co., Ltd. (72) Inventor Takaaki Kondo 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. Inside

Claims (7)

[Claims] 1. At least one of the raw coals constituting the blended coal
Estimate the state of the aromatic fused ring in the coal molecule for one,
A method of measuring coke strength, comprising determining a relationship between the evaluation result and coke strength after carbonization of the coal blend, and estimating the coke strength of the coal blend from the blending ratio using the relationship. 2. At least one of the raw coals constituting the blended coal
For one, the skeletal structure after heat treatment was evaluated, and the relationship between the evaluation result and the coke strength after carbonization of the coal blend was determined.
A method for measuring coke strength, comprising estimating the coke strength of blended coal from the blending ratio using this relationship. 3. The method for measuring coke intensity according to claim 1, wherein the evaluation of the raw coal is performed using a characteristic value of a peak obtained by laser Raman spectroscopy. 4. The method for measuring coke intensity according to claim 3, wherein a characteristic value for a G or D band peak is used as the peak characteristic value. 5. The evaluation of the state of the aromatic condensed ring is performed using a solid
^{2. The} method for measuring coke intensity according to claim 1, wherein the method is performed using characteristic values of a spectrum obtained by a ¹³ C-nuclear magnetic resonance method. 6. The evaluation of the state of the aromatic condensed ring is performed by using a solid
^{2. The} method for measuring coke strength according to claim 1, wherein the method is performed using a degree of aromatic ring condensation obtained from characteristic values of a spectrum of ¹³ C-nuclear magnetic resonance. 7. (a) a step of evaluating the state of the aromatic condensed ring in the coal molecule or a skeleton structure after the heat treatment of the raw coal; and (b) a step of selecting the raw coal using the evaluation result. A method for producing coke, comprising: (c) a step of blending the selected raw coal to produce a blended coal; and (c) a step of carbonizing the blended coal to produce a coke.