RU1809372C - Method of analysis of ash content of coal - Google Patents

Abstract

Usage: coal industry, the determination of the ash content of coal. SUMMARY OF THE INVENTION: it is possible to increase the accuracy of measuring the ash content of coal by forming a coal sample with an area of Sn 5 (11 - 13) Si, where Si is the cross-sectional area of the quasi-monochromatic light flux and a thickness of 4-5 mm, alternating masses m of the angles of each section at the boundary glass with a uniform distribution over the thickness, sealing it while stabilizing the sealing area with a mass of M 80 m with a flat contact area and the same configuration with the measurement area Si, light wave reflection coefficients from hl of each plot and averaging the obtained values. 9 ill. (L C

Description

The invention relates to measuring and control technology and may find application in the coal industry.

The aim of the invention is to improve the accuracy of the measurement of the ash content of dehydrated coal.

On Fig, 1 shows a device that implements the method; in FIG. 2 - 9 - dependences of signals proportional to the reflected light flux from samples of coal of various ash contents and grades, as well as the classes of source coal that were processed into analytical samples; in FIG. 2-for dry samples, grade A coal, grade About - 13 mm TsOF of Sverdlovsk with consolidation; in FIG. 3 - for dry samples, grade G coal, grade 0-13 TsOF Duvans with a seal; in FIG. 4

- for dry samples, coal grade G class. 13 - 50 mm TsOF Belorechensk with a seal; in FIG. 5 - for dry samples of grade G, class thirteen

- 50 mm TsOF of Lugansk with consolidation; in FIG. 6 dl of dry samples, coal grade K, class thirteen

-50mm TsOF Br nkovsk with a seal; in FIG. 7- for dry samples, coal grade K, class 13 - 50 mm TsOF Krivorozhsk with a seal; in FIG. 8 - shows the experimental dependences of constant ash reflected from coal samples, depending on the compaction.

A device that implements the method comprises a light source 1 and photodetectors 2 connected to an electronic unit 3 ... A light source 1 is irradiated with quasimonochromatic through a break glass 4

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light coal sample 5, the volume of which is limited by the ring 6. Directly, the load 7 is installed with a flat contact area and with a configuration corresponding to the configuration of the light flux passing through the dividing glass 4. The reflected signal from sample 5 is recorded by photodetectors 2 and amplified by the electronic unit 3 ..

The method is carried out as follows.

A quasi-monochromatic light flux of area SL is passed through a demarcation glass 4. From a dehydrated sample of coal (flotation waste, flotation concentrate or enrichment products processed into analytical powder), an carbon layer is formed on an additional glass substrate with a thickness of Ah - 4 - 5 mm and area Sn (11 - 13) 5.1, where Si is the cross-sectional area of the quasi-monochromatic light flux. This coal layer is divided into at least 10 equal, for example, square sections. Then, alternately, the volume of the corner of each section is arranged with a uniform layer of thickness 5 on the dividing glass 4 of the device and a load 7 is placed on it. The mass of the load 7 must exceed more than 80 times the mass of the sample 5 located on the dividing glass 4. In FIG. 8 - 9 show the experimental dependences of the signals reflected from coal samples of a given ash content depending on the mass ratio of sample 5 and load 7. In FIG. 9 - for samples of coal grade A of the COF of Sverdlovsk with an ash content of 6%; for samples of coal grade G of the COF of Lugansk with an ash content of 3%. From the data shown in FIG. 8 and 9 that only at a ratio of M / hl 80, where m is the mass of the sample of coal 5, M is the mass of the load 7, the value of the signal reflected from the coal sample 5 is stabilized, therefore, the contact surface of the sample particles with the glass 4 is stabilized. This process is stable only when the area of the seal is kept constant. For this purpose, a ring 6 with a height of mm is installed on the boundary glass 4.

In addition, the value of the signal proportional to the reflected light flux from the angle 5 sample in this case increases by an order, i.e., the sensitivity of the ash measurement method also increases by an order, and therefore the measurement accuracy increases.

The reflection coefficients obtained in this way from 10 samples of angle 5 (from ten

square plots) are averaged and ash values are averaged over these signals.

Since in this case the entire volume of the analytical sample is analyzed, the uniform distribution of ash and coal particles over the volume does not significantly affect the accuracy of determining the ash content. This circumstance, as well as the method described above for stabilizing the contact surface of the sample particles with a glass, and an increase in the sensitivity of the method, made it possible to increase the accuracy of measuring ash samples of coal samples with a particle size of no more than 0.6 mm by more than 5 -10 times. Sensitivity has increased by an order of magnitude (more than 14 μA per 1% ash).

Experimental verification of this method on samples of different grades of coal has confirmed its simplicity and high accuracy. From the data shown in FIG. 2-7, that the standard error of the proposed method for determining the ash content does not exceed 0.15-0.3% by ash content, the correlation coefficient is 0.98-0.99.

Thus, the formation of a coal sample with an area of Sn 5: Si, where Si is the cross-sectional area of the quasimonochromatic light flux and a thickness of at least 4 mm and uniform in thickness, and before measuring the reflection coefficient of the sample, seal it with a mass of M 80 t, where t is the mass a coal sample with a flat contact area and a configuration identical to that of Si can improve the accuracy of measuring the ash content of dehydrated coal of class up to 0.6 mm.

Claims (1)

The claims A method for determining the ash content of coal with particles no larger than 0.6 mm in size, which includes preparing a coal sample on a boundary glass and irradiating it with quasimonchromatic light with a wavelength A of 0.5-0.9 μm through a boundary glass, measuring the reflection coefficient of the sample, according to which the ash content of coal is judged, characterized in that, in order to increase the accuracy of measurements of the ash content of dehydrated coal, in preparing the coal sample, a sample with an area of Sn 2 is formed; Si, where Si is the cross-sectional area of the quasi-monochromatic light flux and at least 4 mm thick and uniform in thickness, and before measuring the reflection coefficient the samples are sealed with a mass of M 80 t, where t is the mass of the coal sample with a flat timing and configuration identical to SL area fie. 2 1 70 VO SO & Q 30 " 7.0 5,0 6.0 7.5 fig & 8.0 g% 7.0 fie.Ј; 8.0 A% 10 § 20 JO 40 50 60 70 JU / m Ф & 2.8