JP6657867B2 - Estimation method of coke shrinkage - Google Patents

Description

  The present invention relates to a method for estimating a coke shrinkage ratio when carbonizing coal under predetermined conditions, and more specifically, for example, predicting a particle size of coke obtained by carbonizing coal, or a method of measuring the strength of coke. The present invention relates to a method for estimating a coke shrinkage rate used in the case of estimating a coke shrinkage.

  In order to further improve the efficiency of the blast furnace operation, the strength and particle size of the coke obtained by carbonizing coal should be stable, that is, it should be possible to produce coke with the target strength and particle size. It has been demanded. In addition, in order to reduce the cost of producing coke, it is necessary to use as much low-priced low-grade coal as possible, such as non-slightly caking coal. It is more important to predict the particle size and strength of the obtained coke in advance because of the decrease in the diameter and the increase in the volume fracture powder ratio.

Among them, when estimating the strength of the coke drum strength index DI ^0.99 ₁₅ which is one of indicators of coke strength is that (for example, see Patent Document 1) is known to be expressed as follows.
DI ¹⁵⁰ ₁₅ = DI ¹⁵⁰ ₆ -DI ¹⁵⁰ _6-15
That is, in Patent Document 1, Takaishi carbonization degree coal and from coal blend obtained by blending a low coalification degree coal in obtaining coke, the drum strength index DI ^0.99 ₁₅ The surface fracture strength DI ^0.99 ₆ and volume breakdown powder discloses a method of estimating divided into the rate DI ^0.99 _6-15, the estimation of the volume fracture powder rate, mixing ratio of vitrinite average reflectance Ro and low coalification degree coal of a high coalification degree coal blending Is used. Here, the drum strength index DI ¹⁵⁰ ₁₅ indicates a lump ratio of 15 mm or more after an impact specified in JIS K2151.

In addition, the volume fracture powder ratio DI ¹⁵⁰ _6-15 was estimated from the solidification temperature of the coal blend, and the surface fracture strength DI ¹⁵⁰ ₆ was calculated from the weighted average of the expansion coefficient or specific volume of each coal constituting the coal blend at the blend ratio. A method of estimating and estimating the strength of coke based on these (see Patent Document 2) is also known.

On the other hand, it is known that the particle size of coke can be estimated based on, for example, the following equation (see Patent Document 3).
Coke particle size of blended coal = a + b x coke shrinkage ratio of blended coal In Patent Document 3, for this formula, coke is produced using blended coal in various blends, and the coke particle size is measured. The coke shrinkage is measured for each coal contained in the coal, and the coke shrinkage in each blended coal is calculated by weighted average according to the blending ratio of each coal, and the coke granules of each blended coal thus obtained are calculated. It is assumed that coefficients a and b are determined by a technique such as regression analysis based on the measured diameter and the calculated coke shrinkage.

  Here, the particle size of the coke and the volume fracture powder ratio are determined due to the macro-cracks on the order of cm in the coke mass. Generally, when coal is carbonized, thermal decomposition or thermal polymerization reaction of an organic polymer structure occurs, and various physical phenomena develop accordingly. That is, the coal softens and melts at about 400 ° C., the particles adhere to each other to form a porous lump, resolidifies at about 500 ° C., and thereafter contracts to become a coke having a more dense structure. At this time, since there is a temperature distribution in the width direction of the carbonization chamber, it is considered that thermal stress is generated due to shrinkage strain and macro cracks are formed. Therefore, in estimating the strength and particle size of coke with high accuracy, It is necessary to understand the coke shrinkage rate in the shrinkage process after resolidification of coal.

  Patent Document 3 discloses a method of measuring the coke shrinkage. That is, in Patent Document 3, the coal is heated to a temperature T (° C.) which is equal to or higher than the resolidification temperature of the coal, and the difference in volume or length of the contents between the resolidification temperature and the temperature T is determined as the volume or length at the resolidification temperature. The value obtained by dividing by the value is defined as the coke shrinkage at the temperature T of the coke produced from the coal. Specifically, coal is charged into the inner thin tube of a sample tube having a dual structure of an inner thin tube provided with a plurality of vents and an outer thin tube, and a piston is placed on the inner thin tube to achieve a predetermined heating rate. And the vertical displacement of the piston with respect to the heating temperature is measured, and the coke shrinkage is determined based on the piston height at the re-solidification temperature and the piston height at the temperature T.

  According to such a method, it is possible to directly measure the coke shrinkage, which is a cause of volume destruction and the occurrence of cracks governing the coke particle size. However, in this method, depending on the type of coal, the piston may be fixed by molten coal or tar, and measurement may not be performed. Further, since the apparatus itself is special, there is a problem that the coke shrinkage cannot be measured at any time.

  On the other hand, there is a report focusing on the relationship between the properties of coal and the coke shrinkage (see Non-Patent Document 1). In Non-Patent Document 1, the coke shrinkage is determined by the method described in Patent Document 3, and it is confirmed that the coke shrinkage and the coke particle size have a correlation. In addition, the relationship between the coke shrinkage rate and the volatile matter (VM) of coal and the degree of coalification have been investigated, but no significant results were found. Is not decided. For reference, FIG. 8 shows the relationship between coke shrinkage and coke particle size described in Non-Patent Document 1 (see FIG. 9 of Non-Patent Document 1).

  By the way, with respect to shrinkage of coke, there are some which have different physical quantities of interest and are defined. For example, in Japanese Patent Application Laid-Open No. 2013-216813 (Patent Document 4), coke after carbonization and a furnace wall of a coke oven are described. The gap (clearance) formed between the brick and the brick is defined as the amount of coke shrinkage. This shrinkage is affected by at least various factors such as temperature distribution and expansion pressure, in addition to the coke shrinkage ratio described above, and is different from the coke shrinkage ratio targeted in the present invention. It is.

JP 2005-194358 A JP-A-9-263768 JP 2005-232349 A JP 2013-216813 A

Seiji Nomura and Takashi Arima (2013) .Effect of coke contraction on mean coke size.Fuel, 105, 176-183.

  As described above, in order to further improve the accuracy of estimating the strength and particle size of coke, it is extremely important to grasp the coke shrinkage in the shrinkage process after resolidification of coal. According to the method described in Patent Document 3, the coke shrinkage at the temperature T when the coal is heated to a temperature T equal to or higher than the re-solidification temperature can be directly measured, but a special device must be used. Measurement may be difficult depending on the type of coal. On the other hand, a technique for estimating the coke shrinkage rate from the properties of coal by industrial analysis has not been established yet.

  Then, the present inventors have conducted intensive studies to solve these problems, and as a result, assuming that the temperature T is a carbonization temperature at the time of obtaining coke from coal, the amount of hydrogen gas generated during carbonization is It was newly found to have a correlation with coke shrinkage. By utilizing this relationship, it is possible to predict the degree of coke shrinkage at the temperature T of the coal and to accurately estimate the coke shrinkage, thereby completing the present invention.

  Therefore, an object of the present invention is to provide a method that can more easily estimate the coke shrinkage regardless of the type of coal.

That is, the gist of the present invention is as follows.
(1) Coal is placed in a container and heated to a temperature T equal to or higher than the re-solidification temperature of the coal, and the difference in volume or length of the contents between the re-solidification temperature and the temperature T is determined by the volume or length at the re-solidification temperature. A method of estimating a coke shrinkage rate at a temperature T of coke generated from the coal, expressed by a value obtained by dividing the coke,
The temperature T is a carbonization temperature when coke is obtained from coal, and was obtained by individually measuring the total amount of hydrogen gas generated when each coal was heated to the temperature T for a plurality of coals . A method for estimating a coke shrinkage ratio, comprising estimating a magnitude of a coke shrinkage ratio at a temperature T of the coal by relatively comparing the total amount of hydrogen gas.
(2) Put the coal in a container and heat it to a temperature T which is equal to or higher than the re-solidification temperature of the coal, and calculate the difference in volume or length of the contents between the re-solidification temperature and the temperature T by the volume or length at the re-solidification temperature. A method of estimating a coke shrinkage rate at a temperature T of coke generated from the coal, expressed by a value obtained by dividing the coke,
The temperature T is the carbonization temperature when coke is obtained from coal, and the total amount of hydrogen gas generated when each of the plurality of test coals whose coke shrinkage at the temperature T is known is heated to the temperature T. By measuring the relationship between the total amount of the hydrogen gas and the coke shrinkage,
For a coal whose coke shrinkage at temperature T is unknown, the coke shrinkage at the temperature T is estimated based on the total amount of hydrogen gas generated when the coal is heated up to temperature T and the relational data. A method for estimating a coke shrinkage ratio, characterized in that:
(3) The coal is placed in a container and heated to a temperature T equal to or higher than the re-solidification temperature of the coal, and the difference in volume or length of the contents between the re-solidification temperature and the temperature T is determined by the volume or length at the re-solidification temperature. A method of estimating a coke shrinkage rate at a temperature T of coke generated from the coal, expressed by a value obtained by dividing the coke,
The temperature T is the carbonization temperature when coke is obtained from coal, and the total amount of hydrogen gas generated when each of the plurality of test coals whose coke shrinkage at the temperature T is known is heated to the temperature T. To obtain a correlation equation between the total amount of the hydrogen gas and the coke shrinkage,
A method of estimating a coke shrinkage ratio, comprising estimating a coke shrinkage ratio from the correlation equation based on a total amount of hydrogen gas generated when a coke shrinkage at a temperature T is unknown.
(4) The coke shrinkage is measured using a sample tube having a double structure of an inner thin tube provided with a plurality of vent holes and an outer thin tube as a container for storing coal. The pipe is charged with coal, the piston is placed on the pipe, and the piston is heated at a predetermined heating rate, and the vertical displacement of the piston with respect to the heating temperature is measured. The method for estimating a coke shrinkage ratio according to any one of (1) to (3), which is calculated based on the following.
(5) The method for estimating a coke shrinkage ratio according to any one of (1) to (4), wherein the temperature T is 800 ° C. or more and 1300 ° C. or less.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is any coal, a coke shrinkage rate can be estimated more easily. Above all, in advance, a correlation equation between the total amount of hydrogen gas generated when heating coal to a predetermined temperature and the coke shrinkage rate is obtained, and if this correlation equation is used, the coke shrinkage rate can be accurately determined. It can be estimated. By establishing a method for estimating coke shrinkage in this way, it is possible to further improve the accuracy of predicting the particle size and strength of coke obtained by carbonizing coal, and to use relatively inexpensive coal such as non-coking coal. It is extremely useful in the production of blast furnace coke, which is increasingly used.

FIG. 1A is an overall schematic explanatory view of an apparatus (high-temperature dilatometer) for measuring a coke shrinkage ratio, and FIG. 1B is an explanatory view showing a state in which a sample (coal) is charged into a sample tube. FIG. 1 (c) is a plan sectional view of the inner thin tube. FIG. 2 is an overall schematic explanatory diagram of a gas monitoring device used for measuring hydrogen gas in the present invention. FIG. 3 is a graph continuously measuring the hydrogen generation behavior of each coal used in the examples. FIG. 4 is a graph showing a correlation between the total amount of hydrogen gas in a coal (the amount of dry carbon dioxide generated) and the coke shrinkage at 1000 ° C., which is a correlation formula according to the present invention obtained in the examples. FIG. 5 is a graph showing the relationship between the total amount of CH ₄ generated in carbonization (the amount of generated CH ₄ ) and coke shrinkage (Comparative Example). FIG. 6 is a graph showing the relationship between the total amount (CH generation amount) of hydrocarbon gas (C = 2 to 4) generated in carbonization and the coke shrinkage (Comparative Example). FIG. 7 is a graph showing the relationship between the volatile matter (VM) of each coal and the coke shrinkage (comparative example). FIG. 8 is a graph showing the relationship between coke shrinkage and coke particle size (see FIG. 9 of Non-Patent Document 1).

Hereinafter, the present invention will be described in detail.
First, the coke shrinkage rate targeted in the present invention is measured by the method described in Patent Document 3, and coal is placed in a container, heated to a temperature T equal to or higher than the re-solidification temperature of the coal, and reheated. It is represented by a value obtained by dividing the difference in volume or length of the contents between the solidification temperature and the temperature T by the volume or length at the resolidification temperature. More specifically, the coke shrinkage can be measured using the apparatus (high-temperature dilatometer) shown in FIG. 1 as follows.

  This device can raise the temperature to a higher temperature (1300 ° C) than a normal dilatometer for testing the expansibility of coal, and has a double structure of an inner thin tube 2 and an outer thin tube 3 as a container for containing coal. The sample tube 4 having the following is used. That is, the apparatus (high-temperature dilatometer) used here heats the sample tube 4, the piston 6 placed on the coal 1 charged in the sample tube 4, and the coal in the sample tube 4 at a predetermined heating rate. An electric furnace 8 having a heater 7 capable of performing the above-mentioned operations, and a laser displacement meter 9 for measuring a vertical displacement of a piston are provided. Among these, the inner thin tube 2 has a plurality of ventilation holes 5 on the surface thereof, so that gas generated by coal can escape to the outside of the inner thin tube 2. This is because if the coal generates a pyrolysis gas during softening and melting and expands greatly, molten coal or tar enters the gap between the piston 6 and the internal thin tube 2 and the movement of the piston is restrained after re-solidification. By providing the vent hole 5 in the inner thin tube 2, the gas at the time of softening and melting is discharged to suppress the expansion, and the shrinkage after the re-solidification can be measured. In addition, a cover 10 is placed on the upper end of the external pipe 3 and acts as a guide for preventing the piston 6 from being axially displaced.

When charging the coal 1 into the sample tube 4, a thin sheet 11 made of paper or the like through which a pyrolysis gas can pass is inserted along the inside of the inner thin tube 2, and the coal pulverized to a predetermined particle size is loaded. Then, the coal in the sample tube 4 is heated at a predetermined heating rate so that the coal does not spill out from the vent hole 5 of the internal thin tube 2. Then, while measuring the vertical displacement of the piston with respect to the heating temperature, the coke shrinkage rate R (−) is obtained from the piston height h at the re-solidification temperature and the piston height h ′ at the temperature T by the following equation (1). ). At this time, in consideration of the thermal expansion of the piston 6 due to the temperature rise, the influence of the piston expansion is obtained in advance as a function of the temperature based on the actual value of the blank, and the coke shrinkage rate according to the equation (1) May be added at the time of calculation.
R = (hh ′) / h (1)

  Here, when specifying the re-solidification temperature when heating the coal by this measurement, as shown in Patent Document 3, the behavior of the piston displacement changes significantly with the temperature rise, and the piston height suddenly increases. The temperature at which it drops can be the re-solidification temperature. Specifically, using the above-described apparatus, the length of the coal 1 during the temperature rise is continuously measured based on the position of the piston 6, and the change in the coal length per unit temperature change is calculated during the temperature rise. Observing the relationship between the length change rate and the temperature, it is found that in the temperature range of 400 to 550 ° C., a temperature at which the length change rate decreases and then sharply increases can be found. What is necessary is just temperature. The change in shrinkage rate per unit temperature change is defined as the shrinkage coefficient (-/ K), and the relationship between shrinkage coefficient and temperature is observed. The shrinkage coefficient decreases in the temperature range immediately before the resolidification temperature of coal. Since the shrinkage coefficient sharply increases in the temperature region immediately after the resolidification temperature, a change in the shrinkage coefficient may be observed, and the temperature at which the shrinkage coefficient sharply increases may be specified as the resolidification temperature of the coal.

  On the other hand, the temperature T can be arbitrarily set as long as the temperature is equal to or higher than the re-solidification temperature. In consideration of using the obtained coke shrinkage for estimating the particle size and strength of coke, The carbonization temperature for obtaining coke from coal is preferably 800 ° C. or higher and 1300 ° C. or lower, and most preferably 1000 ° C.

  In the present invention, such a coke shrinkage is obtained (estimated) without using an apparatus as shown in FIG. That is, the present inventors have found that the coke (or semi-coke) shrinkage phenomenon occurs after the re-solidification of the softened and molten coal, and further, after re-solidification by heating, part of the coke (or semi-coke) is degassed as a gas. It was thought that the coke shrinkage at the carbonization temperature could be estimated based on the total amount of hydrogen gas generated by carbonizing coal, focusing on the hydrogen gas generated when coal was carbonized. Thereby, if the total amount of hydrogen gas generated when the coal is heated to the temperature T which is the carbonization temperature is measured, the coke shrinkage at the temperature T of the coal is determined based on the total amount of the obtained hydrogen gas. The degree can be predicted.

  Specifically, for a plurality of coals, the total amount of hydrogen gas generated when each coal is heated to the temperature T is measured, and these are relatively compared to estimate the magnitude of the coke shrinkage. For a plurality of test coals whose coke shrinkage at temperature T is known, the total amount of hydrogen gas generated when each of them is heated to temperature T is measured, and the total amount of hydrogen gas and coke shrinkage are graphed. The related data may be obtained by plotting or the like, and the coke shrinkage of the new coal whose coke shrinkage at the temperature T is unknown may be estimated therefrom. Among them, preferably, by obtaining the correlation equation in advance as described below, the coke shrinkage of new coal can be accurately estimated.

  That is, for a plurality of test coals whose coke shrinkage at the temperature T, which is the carbonization temperature when obtaining coke from coal, is known, the total amount of hydrogen gas generated when each is heated to the temperature T is measured, It is preferable to obtain a correlation equation between the total amount of hydrogen gas and the coke shrinkage. The correlation equation obtained in this manner can be repeatedly used for a plurality of coals whose coke shrinkage at the temperature T is unknown, and the coke shrinkage can be accurately estimated for each of the coals.

  The method for measuring the total amount of hydrogen generated by carbonization is not particularly limited, and for example, a gas chromatograph-thermal conductivity detector (GC-TCD), which is the most common hydrogen gas measuring method, is used. You may. In this case, the gas generated from the heating start temperature (room temperature) to the carbonization temperature (for example, 1000 ° C.) is stored in a gas sampling bag or the like, and the total amount of generated hydrogen is measured.

On the other hand, the amount of generated coke oven gas (COG) and the amount of heat generated in a coke oven are easily predicted by an experimental device (Reference 1: Patent No. 4050989), and are used for analysis of coal carbonization reaction (Reference) Reference 2: Nishito et al. (2010). Analysis of carbonization reaction of coal by gas monitoring and continuous measurement of gas generated in coke oven. Nippon Steel Technical Report No. 390, 101-111.) Hydrogen generated by carbonization using gas monitoring equipment. May be measured continuously. FIG. 2 shows an overall schematic diagram of this gas monitoring device. In this device, a sample (coal) is supplied while flowing a carrier gas 21 such as nitrogen as an inert gas through a gas purifier 22 and a flow meter 23. The furnace tube 24 made of quartz containing 25) is heated in a tubular electric furnace 26, and the generated gas is transferred through a tar trap 27 to a Fourier transform infrared spectrometer (FT-IR) 29 connected to a computer 30. Is introduced into the cell 28 for gas measurement. Although FT-IR cannot measure hydrogen gas (H ₂ ), a semiconductor-type hydrogen gas sensor 31 such as SnO ₂ having sensitivity to H ₂ is connected to this gas monitoring device. A recorder 32 is attached to the hydrogen gas sensor 31. With such a gas monitoring device, it is not necessary to use a gas sampling bag or the like, and it is possible to continuously measure the amount of hydrogen generated by dry distillation. it can. In the gas monitoring device shown in FIG. 2, the FT-IR is used for the purpose of measuring hydrocarbons in the gas. However, if only the hydrogen gas is measured, it is not necessary to use the FT-IR. What is necessary is just to introduce | transduce into the hydrogen gas sensor 31 directly.

Here, as described in References 1 and 2 above, hydrocarbon gas such as CH ₄ , C ₂ H ₆ and C ₂ H ₄ is mainly generated by dry distillation of coal, in addition to hydrogen gas. However, carbon monoxide and carbon dioxide are slightly generated. Among them, hydrocarbon gas such as CH ₄ is mainly generated in a relatively low temperature range (400 to 700 ° C), and hydrogen gas is mainly generated in a relatively high temperature range (500 to 1000 ° C). As compared with the case where the relationship between the total amount of all generated gases and the coke shrinkage ratio and the relationship between the hydrocarbon gas and the coke shrinkage ratio is focused on, the coke shrinkage using the amount of generated hydrogen gas as an index as in the present invention. It was found that the estimation accuracy was higher when the rate was estimated. In addition, the semi-coke shrinkage phenomenon is generally considered to proceed with the generation of hydrogen gas due to the condensation reaction of the aromatic ring. However, in the present invention, the coke shrinkage rate and the hydrogen gas Was found to be inversely correlated with the amount of hydrogen gas generated (that is, the coke shrinkage decreased as the amount of hydrogen gas generated increased). This unexpected result is not fully understood at this time.

  In the present invention, when measuring the total amount of hydrogen gas generated by heating coal to a temperature T (carbonization temperature), for example, the heating rate is set to a value that simulates the operating condition in a coke oven. It is considered desirable to conform to the coking operation and actual machine conditions. Generally, the rate of temperature rise of coal in dry distillation in a coke oven is about 3 ° C./min, and it has been reported that changing the rate of temperature rise may change the gas generation rate (Reference 3: Takarada et al. (1996). Effect of heating rate and coal type on gas generation behavior during coal pyrolysis Iron and steel Vol.82, 388-392. Was changed in the range of 3 to 10 ° C./min, and the generated gas was examined. As a result, no particular change was found in the generated gas amount. Therefore, the temperature rising rate when measuring the total amount of hydrogen gas can be arbitrarily set at least within this range (the temperature rising rate is 6 ° C./min in the following examples).

  As for the heating start temperature when measuring the total amount of hydrogen gas by heating coal, it is usually sufficient to start heating from room temperature and sum the amount of hydrogen gas generated up to the carbonization temperature (temperature T). However, since the generation of hydrogen gas generally starts from about 400 ° C., in consideration of working efficiency, heating is performed to a carbonization temperature (temperature T) with at least 400 ° C. as a heating start temperature, and the amount of generated hydrogen gas is totalized. You may do so.

  As described above, in a preferred embodiment of the present invention, for each test coal, the total amount of hydrogen gas generated when heated to the carbonization temperature (temperature T) is measured, and the hydrogen content of each test coal is measured. A correlation equation between the total amount of gas and the coke shrinkage of these test coals is obtained. FIG. 4 shows the relationship between the coke shrinkage ratio of the test coal obtained in the example described later and the total amount of the hydrogen gas, and it can be seen that a good correlation is shown. Therefore, if the coke shrinkage at the carbonization temperature (temperature T) is unknown and the total amount of hydrogen gas is measured in the same manner as in the case of the test coal, the coke shrinkage can be estimated from the obtained correlation equation. Becomes possible. The coke shrinkage can be easily estimated without using the device described in Patent Document 3, and the estimation method of the present invention can be applied to any type of coal.

  In order to obtain such a correlation equation, for a test coal having a known coke shrinkage at the temperature T prepared, a plurality of coals having different production areas and brands and different coke shrinkage ratios may be prepared, and are preferably used. It is better to prepare 5 or more, more preferably 10 or more. In this case, since the coke shrinkage is generally about 10 to 18%, it is preferable to include the upper and lower limits of this numerical range.

  In addition, the coke shrinkage of each single coal used for blending is determined by the method of the present invention, and the coke shrinkage of the blended coal is calculated by weighing the coke shrinkage of each single coal obtained according to the blending ratio. Can be estimated. Therefore, based on the coke shrinkage of the blended coal thus determined, for example, the particle size of coke is estimated by the method described in Patent Document 3 described above, or the strength of coke is determined by a known method. If the estimation is performed, a more accurate estimated value can be obtained.

  Hereinafter, the present invention will be described based on examples, but the present invention is not limited to these contents.

(Example 1)
Coals A to F having properties by industrial analysis and elemental analysis shown in Table 1 were prepared. Here, the ash content (dry.%) In the table represents the mass fraction of the amount of ash remaining when heated and incinerated under the conditions specified in the industrial analysis method of JIS M8812, and the volatile content (dry.% ) Is determined by the volatile content determination method also specified in the industrial analysis method of JIS M8812.

  With respect to these coals A to F, the coke shrinkage at a temperature T = 1000 ° C. was determined as follows using the apparatus (high-temperature dilatometer) shown in FIG. That is, the inner thin tube 2 of the device used for the measurement is formed of a SUS cylindrical container having an inner diameter of 8 mm and an outer diameter of 14.5 mm, and holes 5 having a diameter of 1 mm are provided in eight places in the circumferential direction at a distance of 2 mm in the height direction. 368 are provided. The outer thin tube 3 is arranged concentrically with the inner thin tube 2. The material of the outer thin tube 3 is SUS, the inner diameter is 16 mm, and the outer diameter is 24 mm. A piston 6 can be inserted from above into the inner thin tube, and the lower end of the piston 6 has a diameter of 7.5 mm and is disposed so as to be in contact with the upper end of the coal 1 charged in the inner thin tube 2. . Further, the vertical position of the piston 6 can be measured by a laser displacement meter 9, and the electric furnace equipped with a heater 7 on the outer side of the outer thin tube 3 allows the coal 1 charged in the inner thin tube 2 to be measured. The temperature can be heated up to 1300 ° C.

  Then, paper (thin sheet) 11 having a thickness of about 50 μm is charged along the inner circumference of the inner thin tube 2, and 1.25 g of coal pulverized to −3 mm (3 mm or less) is charged therein. , And the temperature was increased to 1000 ° C. by the heater 7 at a rate of 3 ° C./min. At that time, the length of the coal 1 being heated was continuously measured based on the position of the piston 6. In addition, during the temperature increase, the change in coal length per unit temperature change was calculated as the length change rate, and the relationship with the temperature was observed. In the temperature range of 400 to 550 ° C., the length change rate was A temperature which decreased and then increased sharply was found and this temperature was taken as the resolidification temperature of the coal. Such a measurement was carried out for each of the coals A to F, and the coke shrinkage at 1000 ° C. was obtained based on the above-mentioned equation (1). The results are as shown in Table 1.

The total amount of hydrogen gas generated when each of these coals A to F was heated to a temperature T = 1000 ° C. was measured using the gas monitoring device shown in FIG. 2 as follows. A 50 mg coal sample 25 placed in a quartz boat was placed in a quartz furnace tube 24 having an inner volume of about 40 ml, and heated from room temperature to 1000 ° C. at a heating rate of 6 ° C./min from a tubular electric furnace 26. At that time, nitrogen was flowed at a flow rate of 100 ml / min (gas pressure: 0.1 MPa) as the carrier gas 21 through the gas purifier 22 and the flow meter 23, and the coal sample 25 in the furnace tube 24 was cooled in a constant nitrogen flow. It was made to heat. Then, the hydrogen gas (H ₂ ) generated from the coal sample 25 is continuously measured by the semiconductor (SnO ₂ ) type hydrogen gas sensor 31 via the FT-IR gas measuring cell 28 having an optical path length of 2 cm ( The measurement interval was 1 second), and the hydrogen gas concentration (the concentration of hydrogen gas generated from 50 mg of a coal sample: ppm) was determined. The results are shown in FIG. Further, the hydrogen gas detected by the hydrogen gas sensor 31 is based on a calibration curve previously prepared with a standard gas, and the total amount of hydrogen gas generated from each coal when heated from room temperature to 1000 ° C. (from a coal sample of 50 mg). (Total amount of generated hydrogen gas). Table 1 shows the results.

Therefore, a graph showing the relationship between the total amount of hydrogen gas of coals A to G shown in Table 1 and the coke shrinkage at 1000 ° C. of each coal is as shown in FIG. As can be seen from FIG. 4, these have a good correlation, and the total amount of hydrogen gas generated when heated to a temperature T (1000 ° C.) is x (horizontal axis), and coke at 1000 ° C. Assuming that the contraction rate is y (vertical axis), it can be represented by the correlation equation of the following equation (2) (determination coefficient R ² = 0.9429).
y = −0.78x + 18.9 (2)

Incidentally, together with the measurement of the total amount of hydrogen gas of the coals A to F, for each coal, the relationship between the amount of CH ₄ generation measured by the FT-IR29 and the coke shrinkage ratio, and C = 2 to 4 hydrocarbons (HC 5) and FIG. 6 show the relationship between the generation amount and the coke shrinkage ratio, as shown in FIGS. 5 and 6, where the determination coefficients (R ² ) are R ² = 0.599 and R ² = 0.5178, respectively. A graph showing the relationship between the volatile matter (VM) of each coal and the coke shrinkage ratio is as shown in FIG. 7 (determination coefficient R ² = 0.8067). In each case, it is understood that the correlation is inferior to the correlation of FIG. 4 obtained by the present invention. 4 and 5 show the inverse correlation, but the reason is unknown at this time as described above.

  Therefore, for coal H having the properties shown in Table 2 below and whose coke shrinkage at 1000 ° C. is unknown, the total amount of hydrogen gas generated from each coal when heated from room temperature to 1000 ° C. in the same manner as above. The amount (total amount of hydrogen gas generated from 50 mg of coal sample) was determined. The measurement was performed three times, and the average value of 6.86 ml / 50 mg-sample was taken as the total amount of hydrogen gas of coal H, and the coke shrinkage of this coal H at 1000 ° C. was obtained from the correlation equation of equation (2) obtained above. Was calculated, it was estimated to be 12.0% (indicated by □ in the graph of FIG. 4 is the estimated value of coal H).

  Then, when the coke shrinkage of the coal H was actually measured using the previous apparatus which measured the coke shrinkage of the coals A to G, it was 12.1%. That is, it was found that the coke shrinkage rate extremely close to the actually measured value can be estimated by the present invention.

Incidentally, for this coal H, the amount of generation of hydrocarbons (HC) of C = 2 to 4 measured by FT-IR29 was 1.5 ml / 50 mg-sample, and based on this value, the coke shrinkage was obtained from the graph shown in FIG. The rate is estimated to be 13.2%. Similarly, the amount of CH ₄ generated in coal H is 2.5 ml / 50 mg-sample, and the coke shrinkage rate is estimated to be 10.7% based on this value and estimated from the graph shown in FIG. Further, based on the volatile matter (VM) of the coal H, the coke shrinkage rate was estimated to be 12.6% from the graph of FIG. 7, and the results were all inferior to the estimated value according to the present invention.

  As described above, since the total amount of hydrogen gas generated when the coal is heated to the temperature T has a correlation with the coke shrinkage at the temperature T of the coal, even if the above correlation equation is not calculated, If the total amount of hydrogen gas and the coke shrinkage are plotted on a graph, the coke shrinkage of a new coal whose coke shrinkage at the temperature T is unknown can be estimated from the plot. . Alternatively, for example, by measuring the total amount of hydrogen gas generated when each of a plurality of coals is heated to the temperature T, the magnitude of the coke shrinkage ratio can be estimated by comparing the relative amounts of the hydrogen gas and the blast furnace. Various forms of use are expected in the production of coke for use.

1: coal, 2: internal capillary, 3: external capillary, 4: sample tube, 5: vent, 6: piston, 7: heater, 8: electric furnace, 9: laser displacement meter, 10: lid, 11: thin Sheet, 21: carrier gas, 22: gas purifier, 23: flow meter, 24: furnace tube, 25: sample (coal), 26: tubular electric furnace, 27: tar trap, 28: cell for gas measurement, 29: Fourier transform infrared spectroscopy (FT-IR), 30: computer, 31: hydrogen gas sensor, 32: recorder.

Claims (5)

A value obtained by placing coal in a container and heating it to a temperature T equal to or higher than the re-solidification temperature of the coal, and dividing the volume difference or length difference between the re-solidification temperature and the temperature T by the volume or length at the re-solidification temperature. A method for estimating coke shrinkage at a temperature T of coke generated from the coal, represented by
The temperature T is a carbonization temperature when coke is obtained from coal, and was obtained by individually measuring the total amount of hydrogen gas generated when each coal was heated to the temperature T for a plurality of coals . A method for estimating a coke shrinkage ratio, comprising estimating a magnitude of a coke shrinkage ratio at a temperature T of the coal by relatively comparing the total amount of hydrogen gas. A value obtained by placing coal in a container and heating it to a temperature T equal to or higher than the re-solidification temperature of the coal, and dividing the volume difference or length difference between the re-solidification temperature and the temperature T by the volume or length at the re-solidification temperature. A method for estimating coke shrinkage at a temperature T of coke generated from the coal, represented by
The temperature T is the carbonization temperature when coke is obtained from coal, and the total amount of hydrogen gas generated when each of the plurality of test coals whose coke shrinkage at the temperature T is known is heated to the temperature T. By measuring the relationship between the total amount of the hydrogen gas and the coke shrinkage,
For a coal whose coke shrinkage at temperature T is unknown, the coke shrinkage at the temperature T is estimated based on the total amount of hydrogen gas generated when the coal is heated up to temperature T and the relational data. A method for estimating a coke shrinkage ratio, characterized in that: A value obtained by placing coal in a container and heating it to a temperature T equal to or higher than the re-solidification temperature of the coal, and dividing the volume difference or length difference between the re-solidification temperature and the temperature T by the volume or length at the re-solidification temperature. A method for estimating coke shrinkage at a temperature T of coke generated from the coal, represented by
The temperature T is the carbonization temperature when coke is obtained from coal, and the total amount of hydrogen gas generated when each of the plurality of test coals whose coke shrinkage at the temperature T is known is heated to the temperature T. To obtain a correlation equation between the total amount of the hydrogen gas and the coke shrinkage,
A method of estimating a coke shrinkage ratio, comprising estimating a coke shrinkage ratio from the correlation equation based on a total amount of hydrogen gas generated when a coke shrinkage at a temperature T is unknown. The coke shrinkage is measured using a sample tube having a double structure of an inner thin tube provided with a plurality of vents and an outer thin tube as a container for storing coal, and the sample tube is provided with coal. , The vertical displacement of the piston with respect to the heating temperature is measured while heating the piston at a predetermined heating rate, and based on the piston height at the coal resolidification temperature and the piston height at the temperature T, The method for estimating a coke shrinkage ratio according to any one of claims 1 to 3, which is calculated. The method for estimating a coke shrinkage ratio according to any one of claims 1 to 4, wherein the temperature T is 800 ° C or higher and 1300 ° C or lower.

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