JP5391707B2 - Coal expansibility test method - Google Patents

Description

  The present invention relates to a coal expansibility test method for measuring expansibility during coal dry distillation as one of quality evaluation methods for coal for coke production.

  Coal becomes coke by dry distillation. When the temperature of the coal exceeds 300 ° C., the coal is pyrolyzed to generate a gas or a liquid substance, and is softened and melted and expanded. At the same time as the expansion, the particles adhere to each other, degas and shrink to form coke.

  The coking mechanism in the chamber type coke oven is described below. In the chamber type coke oven, the coal is heated from the furnace wall side. This is because the thermal conductivity of coal is low. For example, even if the furnace wall side is coked, the center part in the furnace may be unheated coal. Therefore, the coal in the coke oven in the middle of carbonization is different from the coke layer, softened molten layer, and coal layer from the furnace wall side, and the softened molten layer, which is said to have a thickness of about 10 mm, moves from the furnace wall side to the center side. Move and the carbonization proceeds. The gas and softened melt generated during softening and melting work as a factor for expanding the softened and melted layer, and the softened and melted layer expands while being constrained by the adjacent coke and coal layers. The gas and softened melt generated from the softened molten layer penetrate into the coal layer and the coke layer having higher air permeability, and a part thereof is discharged out of the system.

  During the coking process, the behavior of coal during softening and melting has a very important influence on the properties of coke. Among them, the expansibility of coal has a function of pressing and compressing the coke layer, and is an important parameter in producing a robust coke that can withstand severe use in a blast furnace. In addition, the expansibility has an influence on the extrusion load when the coke is discharged by the extruder after dry distillation, and is an important factor for judging the extrudability.

  Conventionally, the dilatometer method defined in JISM8801 is widely used as a method for measuring the expansion coefficient. In the dilatometer method, pressurized metal is charged into a metal elongated cylindrical tube, a metal piston is installed perpendicularly to the coal, the metal cylindrical tube is heated at a constant heating rate, This is a method of detecting the expansion rate by the displacement of the piston. In the dilatometer method, coal is charged in a metal container, and a piston is disposed above the coal. The weight of the piston is sufficient to constrain the softened melt layer, but the diameter of the piston is approximately equal to the inner diameter of the metal container. For this reason, the gas and liquid substance generated from coal during heating have only a discharge path between the piston and the metal container, and most of the gas generated from the coal and the softened melt acts as a force for pushing up the piston. For this reason, the expansion behavior in the dilatometer method is significantly different from that in the coke oven.

  As a method of solving the above problems, the gas permeation behavior is improved, and a permeable material is disposed between the coal bed and the piston, or between the coal bed and the piston and at the lower part of the coal bed, so that the gas and the liquid substance can permeate. Coal expansibility testing methods are known that increase the number of paths to bring them closer to the expansion behavior in a coke oven. And, if the inner diameter of the metal container is about 8 mm, an expansibility test has been conducted in which the temperature difference between the central part and the peripheral part of the container is small and can be regarded as almost uniform (for example, see Patent Document 1).

  There is also a rapid method aimed at reducing measurement time and maintaining measurement accuracy and reproducibility by improving the dilatometer method (see, for example, Patent Document 2). This method utilizes the fact that the expansion rate of coal depends on the heating rate. As a feature, the temperature distribution in the coal charging container may become non-uniform due to rapid heating, so that the inner diameter of the coal charging container is narrowed to 5 to 12 mm, and in order to maintain reproducibility It is raised that the pulverization particle size of the measurement coal is 250 to 840 μm.

  On the other hand, it is known that microwaves can be used for heating coal. Various studies have been made on the microwave heating of coal (see, for example, Patent Document 3 and Patent Document 4). Patent Document 4 proposes to improve the temperature non-uniformity of an object to be heated by microwave heating.

Japanese Patent No. 2855728 Japanese Examined Patent Publication No. 4-6949 Japanese Patent Publication No. 52-44322 Japanese Patent Laid-Open No. 9-176656

  The metal container used in the dilatometer method has an inner diameter of 8 mm and an outer diameter of 20 mm. The reason why such a thin material is used is that the thermal conductivity of coal is low and the temperature distribution of the coal layer becomes non-uniform when the diameter is increased. In the dilatometer method, coal is pulverized to a particle size of 252 μm or less, measured by pressure molding, and differs greatly from the particle size of coal used in an actual coke oven (3 mm or less, about 80 mass%). The behavior is also different. Of course, it is possible to measure the expansion coefficient of coal pulverized to a particle size of 3 mm or less and about 80 mass% by the dilatometer method. However, since the diameter of the container is 8 mm, unlike the case of the particle diameter of 252 μm, the ratio of particles that contact the wall of the metal container during expansion increases, so the behavior of coal filling the interparticle voids due to expansion is coke. It is hard to say that it can be reproduced as in the furnace. In general, coke heat-treated in a small container such as a dilatometer device is said to have a larger porosity and a larger expansion rate than a chamber furnace coke (for example, Yoshio Suzuki, Shozo Itagaki, “ "Consideration" Iron and Steel, vol. 72, No. 4, 1986, pp. S29.). Therefore, in order to accurately measure the expansion behavior in the chamber furnace coke oven, it can be said that a technique capable of simultaneously achieving an increase in size and uniform heating of the container is necessary.

  Further, as described above, in the dilatometer method, most of the gas and liquid substance generated from coal work as a force for pushing up the piston. In this respect as well, the dilatometer method cannot be said to reproduce the expansion behavior in a chamber type coke oven. The method described in Patent Document 1 using a permeable material for improving the gas permeability can only be heated in a small container due to the problem of uniform heating. It can be said that heating technology is necessary.

  Furthermore, regarding the rapid measurement method described in Patent Document 2, in this method, the inner diameter of the container is defined as 5 to 12 mm, and the pulverized particle size of the measured coal is defined as 250 to 840 μm. As described above, when measuring with a particle size (3 mm or less, about 80 mass%) used in actual operation, the expansion behavior is different because the inner diameter is insufficient. Moreover, according to Patent Document 2, it is described that the reproducibility is greatly reduced when the pulverized particle size of the measured coal is 840 μm or more, and the measurement is performed at the particle size (3 mm or less, about 80 mass%) used in actual operation. Is not practical.

  Therefore, the purpose of the present invention is to enlarge the coal charging vessel for measurement, particularly in the radial direction, thereby reproducing the expansion behavior of the coal in the chamber coke oven, thereby improving the expansion behavior of the coal. It is an object of the present invention to provide a new expansibility measurement test method capable of measuring with high accuracy.

The features of the present invention for solving such problems are as follows.
(1) Coal charged into a measurement coal charging container, an outer container charged with the measurement coal charging container is housed in a heating furnace, and the coal is measured for expansion when the coal is heated A method for testing the expansibility of coal, wherein the coal is heated using a microwave.
(2) The coal expansibility test method according to (1), characterized in that the inner diameter of the measurement coal charging container is more than 12 mm.
(3) The measurement coal charging container is charged into a heat insulating container filled with the same coal as the coal whose expandability is measured, and the heat insulating container is charged into an outer container. Coal expansibility test method according to 1) or (2).
(4) The method according to any one of (1) to (3), wherein the measurement coal charging container is charged into an outer container filled with anthracite coal.
(5) Any one of (1) to (4), characterized in that a material having a through-passage is arranged on the upper and lower surfaces of the measurement coal, and the expansibility is measured by applying a load through the material. The method for measuring the expansibility of coal as described in 1.

  According to the present invention, for the expansibility measurement test at the time of coal dry distillation, by heating with microwaves, even if the capacity of the coal charging container for the measurement is increased, it can be heated uniformly, Since measurement can be performed under a condition in which a load is applied through a permeable material or a packed bed, the expansion behavior of coal in an actual chamber-type coke oven can be reproduced and accurately measured. Furthermore, since a coal charging container can be enlarged, the freedom degree of measurement coal adjustment conditions, such as the increase in the amount of charging coal, and the use of coarse-grained coal (particle diameter 840 micrometers or more), can be raised.

  The measurement results of the expansibility test of coal using the method of the present invention are used as an index for producing a robust coke that can withstand severe use in a blast furnace, and when the coke is discharged by an extruder after dry distillation. As an index for sex determination, it is considered more useful than conventional methods, and coke can be produced efficiently.

It is an example of the microwave heating apparatus used by this invention. It is a side view of one Embodiment of the expansibility measuring apparatus used by this invention. It is a top view of the height in which the thermocouple of one Embodiment of the expansibility measuring apparatus used by this invention is inserted. It is a side view of the expansibility measuring apparatus used in Example 1. It is a top view of the height in which the thermocouple of the expansibility measuring device used in Examples 1 and 2 is inserted. 3 is a measurement result of a coefficient of expansion of coal measured in Example 1. It is a side view of the expansibility measuring apparatus used in Example 2. It is a F charcoal expansion coefficient measurement result when the 0.4 mm glass bead measured in Example 2 is used. It is a F charcoal expansion coefficient measurement result when the 2.0 mm glass bead measured in Example 2 is used. It is a G charcoal expansion coefficient measurement result when the 0.4 mm glass bead measured in Example 2 is used. It is a G charcoal expansion coefficient measurement result when the 2.0 mm glass bead measured in Example 2 is used.

  A normal coal expansibility test is performed by heating coal in a charging container using an electric furnace or the like, but in the present invention, microwaves are used for heating coal. By using microwaves, coal can be heated uniformly even if the charging container for measurement is enlarged. If the charging container can be enlarged, it is possible to measure the expansibility using coal having the same particle size as the coal actually charged in the coke oven. The microwave heating method is internal heating, and the target substance itself can generate heat.However, since the ambient temperature is close to room temperature, if heat insulation is not performed on the outermost part of the target substance, heating will be uneven and expandability will be reduced. There is a possibility that it cannot be measured accurately. Therefore, it is necessary to devise a measuring device that takes measures against heat insulation of the coal to be measured.

  In the present invention, coal is charged into a measurement coal charging container, the measurement coal charging container is further charged into an outer container and accommodated in a heating furnace, and the coal is heated using microwaves adjusted to 915 MHz or 2450 MHz. Measure the expansibility of the coal. It is preferable that the measurement coal charging container is charged into a heat insulating container filled with the same coal as the coal whose expandability is to be measured, and the heat insulating container is charged into the outer container. Moreover, it is preferable that coal such as anthracite is filled in the outer container, and the measurement coal charging container or the heat insulating container containing the measurement coal charging container is charged. An embodiment of the present invention will be described below with reference to the drawings.

  An example of a microwave heating apparatus suitable for use in the present invention is shown in FIG. In the apparatus of FIG. 1, the microwave is transmitted from the microwave generator 1, passes through the waveguide 3, and is irradiated into the applicator 5. The structure required for the microwave heating device 21 is provided with an applicator 5 that is sufficiently wide to install an expansion coefficient measuring device described below, and the microwave can irradiate the applicator 5 without unevenness. Moreover, in order to control a heating rate, the microwave generator 1 needs to be able to change an output freely.

  The expansion coefficient of coal is measured by installing an expansion coefficient measuring device in the applicator 5. One embodiment of the expansion coefficient measuring device is shown in FIG. 2 (side view) and FIG. 3 (plan view of the height of the control thermocouple). The expansion coefficient measuring device 22 has a plurality of containers in a nested structure, and in order from the outside, is an outer container 11, a heat insulating coal 8, a heat insulating container 10, a heat insulating measuring coal 7, and a measurement coal charging container 9. ing. Coal is charged in addition to the measurement coal 6, which is for heat insulation and heat insulation, and to absorb the microwave as much as the measurement coal 6 and maintain the same temperature. Furthermore, in order to make the heat insulation effect uniform, each container is disposed so as to be located in the center in the outer container.

  The measurement coal 6 is adjusted to a predetermined particle size and moisture, and then charged into the measurement coal charging container 9 with a predetermined bulk density. The material of the measurement coal charging container 9 may be a material having a microwave absorption lower than that of coal, that is, a material having a dielectric constant lower than that of coal. Moreover, since the expansion of coal occurs at 400 to 500 ° C., it is necessary to have heat resistance in the temperature range. In order to satisfy these conditions, it is desirable to use quartz for the measurement coal charging container 9.

  The measurement coal charging container 9 is placed in the center of the heat insulation container 10 while the surroundings are filled with the heat insulation measurement coal 7. This is a device for making the temperature distribution uniform. When coal different from the measurement coal 6 is used as the heat insulation coal 8, the microwave absorption characteristics are different, and therefore, there is a possibility that a difference in the heating rate occurs. In order to prevent this, the heat insulation container 10 and the heat insulation measurement coal 7 are further placed in the heat insulation coal 8. Further, a control thermocouple 17 is installed in the measurement coal 7 for heat insulation. When measuring the expansion rate, the heating rate is a very important condition, so it is necessary to control the heating of the measurement coal 6. If the thermocouple 17 is placed in the measurement coal charging container 9, there is a risk of affecting the expansion coefficient measurement result. Also, a metal such as a thermocouple that has a sharp tip tends to concentrate the electric field. Since there is a possibility that the temperature of the peripheral portion will rise rapidly, the control thermocouple 17 is installed in the measurement coal 7 for heat insulation. The measurement coal 7 for heat insulation is charged with the same particle size, bulk density and moisture as the measurement coal 6 in order to equalize the microwave absorption with the measurement coal 6.

  Since the material of the heat insulation container 10 desirably has a low dielectric constant and heat resistance like the measurement coal charging container 9, quartz may be used. However, a material that absorbs microwaves to the same extent as coal and generates heat by itself can be more preferable. For example, graphite, silicon carbide, silicon nitride, etc. can be considered. Since the heated material is coal, graphite is particularly desirable as a material having a chemical composition close to that of coal.

  The heat insulating coal 8 is charged around the heat insulating container 10. Considering the dependence of microwave absorption on the coal brand, the thermal insulation coal 8 is preferably the same brand as the measurement coal 6, but when the measurement coal 6 has a large expansion rate, the measurement coal 6 expands to cause an internal insulation container. It is possible that moving 10 will affect the measurement. Moreover, since the amount of heat insulating coal 8 is larger than that of heat insulating measurement coal 7 and measurement coal 6, when the carbonization degree of the measurement coal 6 is low, the amount of degassed and deliquefied substances increases and the experimental treatment is performed. It takes time and effort. Therefore, as the coal 8 for heat insulation, coal which does not soften and melt and has a small amount of degassing and deliquescent substances, for example, anthracite, is preferable. However, if the heat insulation of the measurement coal and the uniformity of the temperature distribution can be maintained even without the heat insulation coal 8, the heat insulation coal 8 does not need to be charged.

  As for the material of the outer container 11, the heat retention and heat insulation effect of the inner coal and containers, heat resistance, and low microwave absorption are important. Therefore, it is desirable to use quartz for the outer container 11. It is necessary to put nitrogen into the outer container 11 for coal dry distillation, and it is necessary to have a nitrogen inlet 14. Moreover, it is necessary to provide the gas exhaust port 15 for exhausting generated gas. The size of the outer container 11 may be a size that can accommodate the measurement coal charging container 9 and the heat insulation container 10 and can sufficiently insulate the measurement coal.

  The expansion rate is measured by determining the filling height before expansion of coal in advance and measuring the displacement in the height direction of coal during heating. The measurement method is performed, for example, by installing the detection disk 12 on the measurement coal 6, installing the detection rod 13 thereon, and detecting the amount of movement of the detection rod 13 in the height direction. When the detection rod 13 is used, a hole (detection rod port 16) for passing the detection rod through the outer container 11 is required. However, since exhaust gas may be discharged from the detection rod port 16, the diameter of the hole is made substantially equal to that of the detection rod 13 so that no gas is emitted, or the laser displacement meter is not provided with no hole. The displacement of the detection rod 13 may be measured with such a non-contact displacement meter. Furthermore, the materials of the detection rod 13 and the detection disk 12 are required to have a low coefficient of thermal expansion in addition to low heat resistance and microwave absorption. This is because if the thermal expansion coefficients of the detection disk 12 and the detection rod 13 are high, an error in expansion coefficient measurement is increased. Therefore, it is desirable to use quartz as a material.

  Regarding the processing conditions of the measurement coal 6, the pulverization particle size is not particularly limited due to the configuration of the apparatus. It can be measured for coal of any particle size. Similarly, the bulk density is not limited, and the measurement can be performed with a pressure-molded sample.

  Regarding the control of the heating rate, the thermocouple installed in the measurement coal 7 for heat insulation is used as the control thermocouple 17 and the microwave output is adjusted so that the temperature of the control thermocouple 17 becomes the set temperature. Although the microwave output can be adjusted manually, it is desirable to provide an accurate output control device in view of experimental efficiency and accuracy.

  When comparing the present invention with Patent Document 2, it can be said that Patent Document 2 is superior in terms of simplicity. However, according to Patent Document 2, when the inner diameter of the measurement coal charging container becomes larger than 12 mm, the temperature distribution of the measurement coal becomes non-uniform. Under such conditions, it is impossible to accurately measure the expansibility. Is possible. Therefore, when the measurement coal charging container 9 having an inner diameter exceeding 12 mm is used, it is preferable to use the present invention. Further, in the measurement where the inner diameter exceeds 12 mm, the expansion behavior, temperature distribution, and the like can be approximated to actual operations, and the measurement reproducing the expansion behavior of coal in the chamber furnace type coke oven can be realized with high accuracy.

  In the case of performing uniform heating with microwaves, the depth of penetration of the microwaves into the object becomes a problem. Since the microwave attenuates as it penetrates into the inside of the object, there is a limit to increasing the diameter of the measurement coal charging container while achieving uniform heating. In the apparatus of the present invention, as a result of changing the diameter of the measurement coal charging container to 50 mm, it was confirmed that the temperature difference between the center and the surrounding area was within 5 ° C. and uniform heating was possible. Therefore, the inner diameter of the measurement coal charging container used in the present invention is particularly preferably 12 mm to 50 mm.

  In the coke oven, the softened molten layer exhibiting expansion is constrained by the coke layer and the coal layer, and expands while infiltrating gas and the softened melt. When a material that does not have permeability is used for the detection disk 12, the gas generated from the coal during heating and the discharge path of the softened melt are only the gap between the measurement coal charging container 9 and the detection disk 12, and the generated gas and Most of the softened melt stays in the measurement coal and acts as a force that pushes up the detection disk 12. For this reason, when the detection disk 12 does not have permeability, it is expected that the expansion behavior of coal is greatly different from that in the coke oven. Therefore, it is preferable to measure the expansibility by arranging a material having a through path on the upper and lower surfaces of the measurement coal and applying a load through the material having the through path.

  In order to appropriately reflect the expansion conditions in the coke oven, in order to carry out the measurement in consideration of the gas escape of the measured coal 6, a predetermined permeability coefficient of the coke layer or the coal layer to be measured is provided below the detection disk 12. What is necessary is just to arrange | position the material which has a penetration path | route according to. It is preferable to use a permeable material or a filling layer as a material having a through path. Since many permeable materials generally have small pore diameters, they are suitable for simulating layers with low permeability. In addition, since the void diameter can be changed depending on the diameter and shape of the particles used, the packed bed is suitable for simulating a layer having a low permeability to a layer having a high permeability. In the conventional method, the inner diameter of the measurement coal charging container was small, and only a packed bed of particles according to the inner diameter could be configured, but in the present invention, the diameter of the measurement coal charging container can be increased compared to the conventional, The degree of freedom of the diameter of the particles used for the packed bed can be increased, and a packed bed having a coarse pore size with large particles can be configured. As conditions required for the permeable material, heat resistance, low microwave absorption, and low thermal expansion are important. Therefore, quartz filter, glass filter, ceramic filter, ceramic fiber, filter paper, packed bed with spherical particles such as quartz beads, glass beads, ceramic beads, and also irregularly pulverized powder coke, quartz, glass, ceramic It is desirable to use a packed bed of non-spherical particles such as particles. In the case of using particles, it is considered that there are a method using a uniform particle size and a method using a mixture of particles having different diameters. You just have to decide how.

  When a permeable material or a packed layer is disposed under the detection disk 12, the detection disk 12 may impede permeability. Therefore, it is further desirable to use a permeable material, for example, a quartz filter, a glass filter, a ceramic filter, etc. having many pores, for the detection disk 12 as well.

  When coal softens, melts and expands in the coke oven, the coal is constrained by the adjacent coal layer and coke layer. In the present invention, a load is applied from above in order to simulate restraint. When measuring the expansion coefficient when a load is applied to the measurement coal 6, if the material of the detection rod 13 is quartz, the weight is insufficient. The material having a high specific gravity is mainly a metal, but the metal has a high microwave absorption property, and if it is put in the applicator 5, the heating efficiency of coal is lowered. Therefore, the detection rod 13 may be extended outside the applicator 5 and connected to another material having a high specific gravity, such as iron, from the outside of the applicator 5 or may be attached with a weight.

  As the measurement coal, five types of brands (A coal to E coal) were selected from the coals usually used for coke production, and the expansion coefficient measurement test was performed. Table 1 shows the industrial analysis values of the coal used in the test together with the total expansion coefficient measured by the dilatometer method for reference.

As processing conditions of coal, the pulverization particle size was 2 mm or less, 100 mass%, and the water | moisture content of 3 mass%. 4 (side view) and FIG. 5 (plan view of the height of the thermocouple for control) are shown schematically in the expansion coefficient measuring apparatus of the present embodiment. The measurement coal charging container 9 was made of quartz having an inner diameter of 20 mm, an outer height of 50 mm, and a thickness of 1.5 mm. The measurement coal 6 was charged into a measurement coal charging container 9 with a bulk density of 800 kg / m ³ and a filling height of 15 mm. The measurement coal 7 for heat insulation was set to have a pulverized particle size of 2 mm or less, 100 mass%, and moisture 3 mass%, similarly to the measurement coal 6. The bulk density was 800 kg / m ³ and the filling height was 30 mm. As the heat insulating container 18, a cylindrical graphite container having an inner diameter of 50 mm, a container inner height of 50 mm, and a thickness of 10 mm was used. Moreover, the graphite base 23 was arrange | positioned under the container for heat insulation. The graphite base 23 was 30 mm high and 10 mm thick. The reason for installing the foundation is to reduce the amount of tar and gas derived from the thermal insulation coal discharged outside the system by reducing the amount of the thermal insulation coal 8 and does not particularly affect the measurement results. . As the heat insulating coal 8, anthracite having the properties shown in Table 2 was used. The treatment conditions for the heat insulating coal 8 were the same as those of the measurement coal 6, and the pulverized particle size was 2 mm or less, 100 mass%, water 6 mass%, and bulk density 800 kg / m ³ .

  A quartz separable flask was used for the outer container 19. The lower flask used was a cylindrical type having an inner diameter of 145 mm, an inner height of 85 mm, and a thickness of 5 mm, and the upper flask was an hemispherical type having an inner diameter of 145 mm, an outer height of 80 mm, and a thickness of 5 mm. The detection disk 12 was a cylindrical cylinder with a diameter of 18 mm and a height of 3 mm. The detection rod 13 was made of quartz having a diameter of 6 mm and a length of 350 mm, and an end opposite to the measurement coal 6 was taken out from the upper part of the applicator 5 and connected to an iron rod for detecting the expansion of the measurement coal 6. The iron rod is a weight. As the amount of expansion of the measurement coal, the amount of movement of the detection rod in the height direction due to the expansion of the measurement coal was measured by the laser displacement meter 20 from the upper side of the applicator. The measurement coal 6 was heated from 0 ° C. to 600 ° C. at a heating rate of 3 ° C./min, and the expansion amount at that time was measured. The expansion coefficient here is a ratio of displacement in the height direction due to expansion with respect to the filling height of 15 mm, and the maximum expansion coefficient in the range of 350 to 550 ° C. was defined as the expansion coefficient of the measurement brand.

  First, in order to examine reproducibility, the expansion rate was measured twice for the brand A. FIG. 6 shows the measurement results of the heating temperature and the expansion rate of the brand A, and Table 3 shows the average value of the expansion rate and the measurement error.

  When the first and second expansion behaviors were compared, a slight difference was observed between the expansion start temperature and the expansion speed, but the maximum expansion rates were almost equal. The allowable error of the dilatometer method of JISM8801 is 18.9% when the expansion rate is 170%, and the maximum expansion rate measured by the expansibility test method of the present invention has no problem in accuracy compared with the prior art. It can be said.

  From the above results, the expansibility test method of the present invention can accurately measure the expansion behavior of coal. Table 4 shows the results when the expansion rates of the five brands were measured by the expansibility test method of the present invention.

  The result shown in Table 4 shows the characteristic expansion rate of each brand.

  Using the method of the present invention, an expansion coefficient measurement test was performed in a state where a load was applied and restrained through a permeable material. Since the coal layer in the coke oven, the aeration condition of the coke layer, and the restraint conditions vary depending on the operating state of the coke oven, the combination of coal blending, etc., it is considered important to be able to measure under various conditions. In this study, an expansion rate measurement test was conducted when the ventilation condition and the constraint condition were changed by two levels.

  Two kinds of brands (F charcoal and G charcoal) were selected from coals usually used for coke production as measurement coal. The industrial analysis values of the coal used in the test are shown in Table 5 together with the total expansion measured by the dilatometer method for reference.

The processing conditions for the measurement coal were a pulverized particle size of 2 mm or less, 100 mass%, and moisture 3 mass%. FIG. 7 (side view) and FIG. 5 (plan view of the height of the thermocouple for control) are shown schematically in the expansion coefficient measuring apparatus of the present embodiment. The measurement coal charging container 9 was made of quartz having an inner diameter of 20 mm, an outer height of 100 mm, and a thickness of 1.5 mm. The measurement coal 6 was charged into a measurement coal charging container 9 with a bulk density of 800 kg / m ³ and a filling height of 10 mm. The measurement coal 7 for heat insulation was set to have a pulverized particle size of 2 mm or less, 100 mass%, and moisture 3 mass%, similarly to the measurement coal 6. The bulk density was 800 kg / m ³ and the filling height was 30 mm. As the heat insulating container 18, a cylindrical graphite container having an inner diameter of 50 mm, a container inner height of 50 mm, and a thickness of 10 mm was used. A graphite base 23 is disposed under the heat insulating container 18. The graphite base 23 was 30 mm high and 10 mm thick. As the heat insulating coal 8, anthracite having the properties shown in Table 2 was used. The treatment conditions of the heat insulating coal 8 were the same as those of the measurement coal 6, and the pulverized particle size was 2 mm or less, 100 mass%, water 6 mass%, and bulk density 800 kg / m ³ . A quartz separable flask was used for the outer container 19. The lower flask used was a cylindrical type having an inner diameter of 145 mm, an inner height of 85 mm, and a thickness of 5 mm, and the upper flask was an hemispherical type having an inner diameter of 145 mm, an outer height of 80 mm, and a thickness of 5 mm.

  A glass bead packed layer was used as the permeable material. 22.5 g of glass beads 24 were charged on the coal filled in the measurement coal charging container, and a quartz filter 25 having a diameter of 19 mm and a pore diameter of 100 to 160 μm was placed on the glass beads. This quartz filter is an alternative to the expansion detection disk. The detection rod 13 was made of quartz having a diameter of 6 mm and a length of 350 mm, and an end opposite to the measurement coal 6 was taken out from the upper part of the applicator 5 and connected to an iron rod for detecting the expansion of the measurement coal 6.

  As a coal restraint condition, a load was applied from the top of the coal bed. A weight 26 is attached to the upper part of the iron rod so that a predetermined load can be applied to the measurement coal through the quartz filter 25 and the glass beads 24.

  The expansion coefficient was measured using a laser displacement meter. The amount of movement of the detection rod in the height direction was measured by the laser displacement meter 20 from the upper side of the applicator, and the result of dividing the displacement by the filling height of 10 mm was taken as the expansion coefficient.

  Under the above conditions, the measurement coal 6 was heated from 0 ° C. to 550 ° C. at a nitrogen flow rate of 2.5 L / min and a heating rate of 3 ° C./min, and the expansion coefficient at that time was measured. Glass beads having a diameter of 0.4 mm and a diameter of 2 mm were used, and the expansion coefficient was measured in each case. Moreover, the expansion coefficient was measured about the case where 2 kPa and 50 kPa were added about the load, respectively.

  The measurement results are shown in FIGS. FIG. 8 shows F charcoal when 0.4 mm glass beads are used, FIG. 9 shows F charcoal when 2.0 mm glass beads are used, and FIG. 10 shows G charcoal when 0.4 mm glass beads are used. FIG. 11 shows the measurement results of G charcoal when 2.0 mm glass beads are used. As shown in FIGS. 8 to 11, it was confirmed that the expansion behavior was different when the glass bead diameter and the load were changed. In particular, as shown in FIG. 9, for the result of measurement with 2.0 mm glass beads and a load of 50 kPa for F charcoal, an interesting behavior was shown in which the expansion once occurred and then contracted. The coke layer also contains many cracks, and there is a possibility that coarse voids existing in the 2.0 mm glass bead packed layer also exist in the coke layer. By measuring the expansion coefficient using the method of the present invention, the expansion behavior of an actual furnace can be appropriately reproduced. The expansion coefficient measured using the method of the present invention is a parameter for producing high strength coke. In addition, it can be applied as an index of coke extrudability.

DESCRIPTION OF SYMBOLS 1 Microwave generator 2 Isolator 3 Waveguide 4 Power monitor 5 Applicator 6 Measurement coal 7 Measurement coal for heat insulation 8 Coal for heat insulation 9 Measurement coal charging container 10 Heat insulation container 11 Outer container 12 Detection disk 13 Detection rod 14 Nitrogen Inlet 15 Gas outlet 16 Detection rod port 17 Control thermocouple 18 Insulating graphite container 19 Quartz separable flask 20 Laser displacement meter 21 Microwave heating device 22 Expansion coefficient measuring device 23 Graphite base 24 Glass beads 25 Quartz Made filter 26 weight

Claims (5)

Charging coal to be measured for expansion into a measurement coal charging container,
The measurement coal charging container is charged into a heat insulating container filled with the same coal as the measurement target coal,
The thermal insulation container is charged into an outer container,
The outer container charged with the measurement coal charging container is accommodated in a heating furnace,
Wherein wherein the benzalkonium measuring the swelling of the coal when heated coal to be measured, expandable test method for coal using microwave. Charging coal into the measuring coal charging container,
The measurement coal charging container is charged into an outer container filled with anthracite coal,
The outer container charged with the measurement coal charging container is accommodated in a heating furnace,
The coal and wherein the benzalkonium measuring the swelling of the coal when heated, the expansion testing method coal using microwave. Charging coal to be measured for expansion into a measurement coal charging container,
The measurement coal charging container is charged into a heat insulating container filled with the same coal as the measurement target coal,
The thermal insulation container is charged into an outer container filled with anthracite,
The outer container charged with the measurement coal charging container is accommodated in a heating furnace,
Wherein wherein the benzalkonium measuring the swelling of the coal when heated coal to be measured, expandable test method for coal using microwave. The method for testing the expansibility of coal according to any one of claims 1 to 3, wherein the inner diameter of the measurement coal charging container is more than 12 mm.   The material according to any one of claims 1 to 4, wherein a material having a through-passage is disposed on the upper and lower surfaces of the measurement coal, and the expansibility is measured by applying a load through the material. Coal expansibility measurement method.

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