JPS5973754A - Automatic analysis of coal structure - Google Patents

Abstract

PURPOSE:To obtain a measuring result with high reliability by the accerelation and generalization of analysis, by a method wherein the average reflectivity of a vitrinite structure is measured and a state such that resistivity is equal to or less than the value determined by using the relation of said reflectivity and the max. reflectivity of noise to be measured through resin and the deference of the reflectivities between adjacent two points is within a definite range is judged as noise to be measured through resin which is, in turn, removed to perform automatic analysis. CONSTITUTION:A specimen 10 is placed on a scanning stage 2 and the focus is adjusted. In the next step, a measuring condition is keyed in from an I/O typewriter 9 to a calculator 7 to start measurement. The scanning stage 2 performs stage scanning through a stage control circuit 4 by the order of the calculator 7. As the scanning method of scanning stage, there are two kinds (a), (b). The reflected light from each measuring position is received by a photoelectronic multiplier 3 through a filter and a sight iris and integrated by an integrator 5 for the sake of the enhancement of a S/N ratio while the integrated value is stored in the calculator 7 as a reflectivity signal along with position information through an interface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a method for automatically analyzing the structure of coking coal for blast furnace coke, and aims to improve the accuracy of the measurement.

Microstructural analysis of coking coal for blast furnace coke is extremely important not only for quality control of incoming coal but also for quality control of finished coke.Especially in Japan, due to the coking coal situation, it is necessary to accurately understand coking properties of coking coal. There is a need.

Textural analysis of coal involves quantifying the content of microstructural components in coal and the reflectance of vitrinite, which is the main component of coal and has a uniform structure, using a microscope, but it cannot be measured manually. However, since there is a limit to the number of measurement points and the individual error of the measurer is large,
Recently, automation of tissue analysis has been progressing.

This automatic measurement method basically uses a computer to process the information, and in most cases measures the reflectance at a very large number of points, and then mathematically and statistically processes the reflectance distribution curve. is used. Other than this method, a method is known in which the vitrinite structure is determined and counted based on the difference in reflectance between two adjacent points or between points above, below, left and right.

However, these conventional automatic measurement methods are based on the reflectance distribution as described above, so the reflected light from the coal that has sunk below the polished surface of the coal is measured through the molded resin in which the coal particles are embedded. The reflected noise (hereinafter referred to as under-resin noise) has a reflectance distribution that overlaps that of exginite.

FIG. 1 is a diagram showing an example of the reflectance range of a coal structure.

The horizontal axis shows the reflectance, and in the figure (1) is Inertinit, (
SF) is semi-fujiknit, (■) is vitrinite, (E
) is exginite, and (N) is under-resin noise. As is clear from the figure, the noise under the resin (N) is
) and the reflectance distribution overlap. For this reason, there is a drawback that under-resin noise is misidentified as exginite and counted, and the measurement accuracy is insufficient, making it impossible to obtain satisfactory analytical values.

This invention was made in view of the above-mentioned circumstances, and its gist is to use vitrinite in an automatic coal structure analysis method that measures the reflectance of a coal sample at a very large number of points and processes the information. The average value of the reflectance is determined and calculated in advance.

The reflectance is less than or equal to the value determined using the relationship between the average reflectance of Vitrinit and the maximum reflectance of noise under the resin, and the difference in reflectance between two adjacent points is within a certain range. A feature of this method is that if the noise is within the concave area, it is determined to be noise under the resin, and the coal structure is analyzed by excluding it from the measurement data.

The details of this invention will be explained below.

The inventors investigated in detail the characteristics of the line profile of the reflectance of noise under the resin using a polarized reflection microscope equipped with a scanning stage capable of step scanning over minute distances of several microns. Here, the line profile of the reflectance is obtained by placing one sample, which is embedded in resin and polished, on a scanning stage, and moving the scanning stage at a constant speed of Xl! This is obtained by recording the 7u signal from the photoelectron j-multiplier with a recorder while moving in the 1111 direction. Figure 2 is a diagram showing an example of the waveform of the line profile of the noise under the resin. , the axis is the scanning hole 1, and the vertical axis is the reflectance.As a result of this investigation, it has been found that the under-resin noise has the following characteristics.

(2) FIG. 3 is a diagram showing the relationship between the maximum reflectance of under-resin noise and the average reflectance of vitrinite in the present invention. The horizontal axis is the SV average reflectance R8 of Vitrinit, and the vertical axis is the maximum reflectance Rt of under-resin noise.

(2) We also found that the difference in reflectance between two adjacent points was within the range shown in Table 1.

Table 1 The inventors have found the following criteria for determining under-resin noise by utilizing the characteristics of (1) and (2) above. That is, a case where the reflectance is below the RN and the difference in reflectance between two points is within the range shown in Table 1 above is determined to be under-resin noise. By storing this criterion in the computer, the actually measured reflectance is compared with the criterion to determine whether there is under-resin noise. In this way, the present invention makes it possible to remove under-resin noise, which was impossible with the prior art, and therefore makes it possible to extremely improve measurement accuracy.

As mentioned above, the Tsukuda microscopic tablet according to the present invention is equipped with a scanning stage capable of step scanning over a minute distance of several microns, and a photometric device for measuring reflected light from coal. The scanning stage has a minimum chip width of 1
μ, scanning speed loo 5teps/min, scanning range 20
Although a photomultiplier tube with a 1MX20sr* function and a high-voltage stabilized power supply is used as the photometric device, a television camera having such a function may also be used.

The computer also includes an interface, a storage device, and an input/output device, and serves as the drive side of the scanning stage.

FIG. 4 is a block diagram showing the configuration of an apparatus for carrying out the present invention. m is a polarized reflection microscope equipped with a scanning stage (2) and a photomultiplier tube (3). (4
) is a stage movement control circuit, (5) is an integrator, (6) is a hull Φ converter, (7) is a calculator, (8) is a line printer, and (9) is an I10 typewriter.

That is, first, the sample (1o) is placed on the scanning stage (2).
Place and focus. Next, measurement conditions are entered from the Ilo typewriter (9) into the computer (7) and then measurement is started. The scanning stage (2) includes a computer (7
1 through the stage control circuit (4).
A step scan is performed with a step width of μ, 2.5μ, or 5μ. FIG. 5 is a diagram showing a scanning method of the scanning stage. There are two modes, a and b, and in both cases, a range of 10 m x 10 t1 m to 20 tx x 20 MMcD is scanned.

The reflected light from each measurement position is received by a photomultiplier tube (3) via a 546 nm filter and a field diaphragm (measuring field of view diameter 1μ or 2μ), and is transmitted over several msec to improve the S/N ratio. After being integrated by the integrator (5) for ~10m5ec, the reflectance signal A is sent to the computer (7) via the interface along with the position information (,Tj,'; J=).
It is stored as I,5. Here, the name is t from the start of measurement.
This is a subscript indicating the th measurement point.

Next, the measured Aa is converted into R from a reflection signal prepared by measuring a reflectance standard sample in advance and a calibration curve of reflectance R0, and Xλ*k p Roi is stored. The measured and stored χj, , '3jJ* Rap is compared with the under-resin noise determination criteria stored in the computer in advance to remove under-resin noise, and then tissue discrimination and quantification is performed.

Table 2 shows the amount of under-resin noise determination when visual determination of the same location and automatic determination using this invention method are simultaneously performed using the apparatus implementing this invention method illustrated in FIG. The ratio of the automatic judgment amount to the visual judgment amount, that is,
It shows the noise removal rate under the resin.

Table 2 As is clear from Table 2, the method of the present invention shows that it is possible to very accurately determine and remove under-resin noise.

Table 3 shows both the results of tissue analysis performed using the method of this invention and the results of manual analysis.

Table 3: However, E: Exginite ■: Vitrinit SF: Semi-Fujinite I: Inertinite R: Average reflectance of Vitrinit As is clear from Table 3, the tissue analysis values obtained by this invention method and those obtained by manual analysis are extremely different. Good agreement was shown.

As explained above, the method of this invention not only allows highly reliable measurement results to be obtained without using the palm of the hand, but also speeds up and generalizes tissue analysis (can be applied to any type of coal or by an experienced person). It is possible to expand the practical application of coal structure analysis, and it has a great effect on quality control of incoming coal, determining the grade and blend of newly purchased coal, and predicting the quality of finished coke. It has the following.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of the reflectance range for each coal structure, Fig. 2 is a diagram showing an example of the waveform of the line profile of noise under the resin, and Fig. 3 is a diagram showing an example of the waveform of the line profile of noise under the resin in this invention. A diagram showing the maximum reflectance and the average reflectance of vitrinite, FIG. 4 is a block diagram showing the configuration of an apparatus for carrying out this invention,
FIG. 5 is a diagram showing a scanning method of the scanning stage. In the figure, 1... polarizing microscope, 2... scanning stage, 3
...Photomultiplier tube, 4...Stage movement control circuit,
5... Integrator, 6... A/D converter:, 7... Computer, 8... Line printer, 9... I10 typewriter-110... Sample. Applicant: Sumitomo Metal Industries, Ltd. Figure 1 Figure 2 272- Figure 3 +r: + Scream 2 (

Claims (1)

[Claims] In the automatic coal structure analysis method, which measures and analyzes the reflectance of a coal sample at a very large number of points, the average reflectance of the vitrinite structure is measured, and the relationship between this reflectance and the maximum reflectance of noise under the resin is determined. If the reflectance is less than the value determined using the method, and the difference in reflectance between two adjacent points is within a certain range, it is determined to be under-resin noise, excluded from the measurement data, and automatically analyzed. An automatic analysis method for coal structure, characterized by: