JP6056157B2 - Coke blending coal composition determination method and coke manufacturing method - Google Patents

Description

  The present invention relates to a method for determining a blended coal composition for coke, which accurately predicts coke strength when carbonizing coal blend to produce coke. In particular, a coke blending coal composition determination method that makes it possible to predict coke strength with high accuracy using the penetration distance and maximum fluidity, which are indices that can accurately evaluate softening and melting characteristics (thermal plasticity) during coal carbonization, and The present invention relates to a coke production method that uses the coke blending coal composition determination method to enable stable management of coke strength.

  Coke used in the blast furnace method, which is most commonly used as a steelmaking method, plays a number of roles, such as iron ore reductant, heat source, and spacer. In order to operate the blast furnace stably and efficiently, it is important to maintain the air permeability in the blast furnace, and therefore production of coke having high strength is required. Coke is produced by dry-distilling blended coal in which various types of coal for coke production, which are pulverized and adjusted in particle size, are blended in a coke oven. Coal-producing coal softens and melts in the temperature range of about 350 ° C to 550 ° C during dry distillation, and at the same time foams and expands with the generation of volatile matter, so that each particle adheres to each other, and lump-like semi-coke and Become. Semi-coke is burned by shrinkage in the process of raising the temperature to around 1000 ° C., and becomes robust coke. Therefore, it can be said that the adhesion characteristics during softening and melting of coal have a great influence on properties such as coke strength and particle size after dry distillation. Therefore, conventionally, evaluation of softening and melting characteristics of coal has been regarded as very important, and has been measured by various methods and used as a management index of coke strength. In particular, coke strength, which is an important quality of coke, is greatly affected by the properties of coal as the raw material, particularly the degree of coalification and softening and melting characteristics. The softening and melting characteristics are usually measured and evaluated by the fluidity, viscosity, adhesiveness, etc. of the softening melt.

  Among the softening and melting characteristics of coal, a general method for measuring the fluidity at the time of softening and melting includes a coal fluidity test method by the Gieseler plastometer method defined in JIS M8801. In the Gisela plastometer method, coal pulverized to 425 μm or less is put into a predetermined crucible, heated at a specified temperature rise rate, measured for the rotation speed of a stirring rod with a specified torque applied, and divided into scales every minute. This is a method for expressing the softening and melting characteristics of a sample.

  As other softening and melting property evaluation methods, a method of measuring torque by a constant rotation method, a method of measuring viscosity by a dynamic viscoelasticity measuring device, and a dilatometer method defined in JIS M8801 are well known.

  As a method for evaluating softening and melting characteristics different from the above method, Patent Document 1 proposes a method for evaluating softening and melting characteristics under conditions that consider the situation where a softening melt of coal is placed in a coke oven. Has been. In the method of Patent Document 1, measurement is performed under conditions in which softened and melted coal is constrained, and under conditions simulating the movement and penetration of the melt into the surrounding defect structure, and the penetration measured by this method. It is known that the distance is an indicator of coal softening and melting characteristics different from the conventional method.

JP 2010-190761 A

Miyazu et al .: “Nippon Steel Pipe Technical Report”, vol. 67, 1975, pages 125-137. Yamamoto et al .: “Iron and Steel”, vol. 62, 1976, p. 38

  Since the softening and melting characteristics of coal greatly influence the coke strength when coke is produced using the coal, it is important to improve the evaluation accuracy of the softening and melting characteristics. In addition, in order to increase the coke strength, it is also important to select a coal brand to be used based on the evaluation result of the softening and melting characteristics of the coal, or to adjust the blending amount of a certain coal brand. However, in the conventional softening and melting evaluation method as shown in Patent Document 1, the correlation between the measured characteristics and the coke strength is weak, and improvement of the evaluation method has been desired for the control of the coke strength.

  In order to evaluate the softening and melting behavior of coal in a coke oven more accurately than the conventional evaluation method, the softening and melting characteristics of coal are measured in a state simulating the environment surrounding the softened and melted coal in a coke oven. It is necessary. In the production of metallurgical coke, it is common to use blended coal that is a mixture of several brands of coal at a specified ratio. However, if the softening and melting characteristics cannot be evaluated correctly, the required strength is satisfied. Coke cannot be produced. When low-strength coke that does not satisfy the specified strength is used in a vertical furnace such as a blast furnace, the amount of powder generated in the vertical furnace is increased, resulting in an increase in pressure loss and the operation of the vertical furnace. May cause troubles such as so-called blow-through, in which the gas flow is locally concentrated.

  In the coke oven, the coal at the time of softening and melting is softened and melted while being constrained by adjacent layers. Since the thermal conductivity of coal is small, the coal is not heated uniformly in the coke oven, and the state differs from the coke layer, softened molten layer, and coal layer from the furnace wall side that is the heating surface. Since the coke oven itself expands somewhat during dry distillation but hardly deforms, the softened and melted coal is constrained by the adjacent coke layer and coal layer. Therefore, it is important for the evaluation of the softening and melting characteristics to perform measurement under conditions simulating the constraints of the adjacent coke layer and coal layer.

  Moreover, it is considered that the softened and melted coal moves to the voids existing around it. There are various types of voids around the softened molten layer, such as voids between coal particles in the coal layer, voids between particles of the softened molten coal, rough air holes generated by volatilization of the pyrolysis gas, and cracks generated in the adjacent coke layer. In particular, the crack generated in the coke layer is considered to have a width of several hundred microns to several millimeters, and is larger than the voids and pores between coal particles having a size of about several tens to several hundreds of microns. For this reason, it is considered that not only pyrolytic gas and liquid substances, which are by-products generated from coal, but also softened and melted coal itself moves to coarse defects generated in such a coke layer. Therefore, in order to more accurately evaluate the softening and melting characteristics of coal, it is necessary to measure by simulating the penetration conditions of surrounding defect structures, particularly coarse defects.

  Furthermore, in order to more accurately evaluate the coal softening and melting characteristics in the coke oven for various coal brands, the range in which the coal is softened and melted in the coke oven and moved to the surrounding defect structure or deformed. It is necessary to measure under the shear rate inside. In this case, the shear rate is expected to vary from brand to brand. Therefore, it is required to set the measurement conditions so that the deformation and movement behavior of each brand during softening and melting is equal to the behavior in the coke oven. It is done. Therefore, when evaluating the coal softening and melting characteristics based on the coal softening and melting behavior in the coke oven, it is necessary to reproduce the shear rate in the coke oven, not under a constant shear rate. It is necessary to control properly.

  As described above, in order to measure the softening and melting characteristics of coal in a state of simulating the environment around the softened and melted coal in a coke oven, it is necessary to make the restraint conditions and infiltration conditions appropriate. Therefore, the inventors have proposed a method for evaluating the softening and melting characteristics described in Patent Document 1. However, there is a problem that the influence of the permeation distance required by the method of Patent Document 1 on the coke strength has not been fully elucidated.

  Furthermore, in the conventional technique using the softening and melting property index, the coke strength is set by setting the target coke strength higher in advance in consideration of the variation in the coke strength resulting from the inaccuracy of the evaluation of the softening and melting property. In this method, it is necessary to use a relatively expensive coal with excellent softening and melting characteristics and to set a high average quality of the blended coal. For this reason, there is a problem in that the cost is increased.

  In order to solve the above-mentioned problems, the object of the present invention is to use coke after dry distillation using a property parameter calculated on the basis of the maximum fluidity (MF) and the penetration distance, which shows more accurate softening and melting characteristics of coal. A method for predicting the strength of coal with high accuracy is provided, and a blending coal composition determination method for coke that determines suitable blending conditions for producing coke having a desired strength based on the predicted strength is provided. That is.

  In addition, the present invention eliminates the need to set the average quality of the blended coal higher than necessary by predicting the coke strength with higher accuracy than the conventional method by this blended coal composition determination method for coke, It is also possible to provide a method for stably producing coke having a desired strength by reducing the amount of high-grade coal used while maintaining the coke strength, enabling efficient use of resources and reducing production costs. Objective.

The gist of the present invention for solving the above problems is as follows.
(1) A method for determining the composition of a coke for coke produced by dry distillation of a coal blend containing a plurality of brands of coal, from a combination coal to be investigated including a plurality of brands of coal The coke strength of the prepared coke is measured, and the maximum fluidity (MF) ddpm and the permeation distance mm of each of the multiple brands of coal included in the survey coal blend are measured, and the measured coke strength is measured. Coke of coke produced from coal to be predicted containing multiple brands of coal with explanatory variables including property parameters calculated based on maximum fluidity (MF) and permeation distance as objective variables and the objective variables Create a regression equation that predicts the strength, predict the coke strength of the coke to be produced based on the regression equation, and the predicted coke strength is within a predetermined management range Sea urchin, coking coal blend composition determination method characterized by determining the mixing ratio of coal stocks and a plurality of securities included in the prediction target coal blend.
(2) From the following formula (1), the deviation penetration distance of each brand of coal in the survey coal blend is calculated from the measured value of the penetration distance and maximum fluidity of each brand in the survey blend. According to the following formula (2), the weighted average deviation penetration distance obtained by weighted averaging the deviation penetration distance of each brand of coal according to the blending ratio of each brand of coal in the surveyed blended coal The blended coal composition determination method for coke according to (1) above, wherein the weighted average deviation penetration distance is used as the property parameter.

Here, a is a common logarithmic value (log MF) of penetration distance and maximum fluidity (MF) of at least one or more coals that can be used as a raw material for coke, which is in a range of 1.0 <log MF <2.5. ) And a regression line passing through the origin from a plurality of sets, the value of the ratio of the change amount of the penetration distance to the change amount of the log MF with respect to the regression line, Log MF is the common logarithm of the maximum fluidity. However, when the value on the right side of equation (1) is less than or equal to zero, the deviation penetration distance is 0. And

Here, α _i is the blending ratio of coal _i of each brand in the surveyed blended coal, and (deviation penetration distance) _i is the deviation penetration distance of coal _i of each brand in the surveyed blended coal. Yes, N is the total number of coal brands constituting the survey coal blend.
(3) From the measured values of the penetration distance and the maximum fluidity of each brand of coal in the surveyed blended coal, the following formula (3) according to the blending ratio of each brand of coal in the surveyed blended coal, ( 4) Calculate the weighted average penetration distance and the weighted average log MF of the formula, calculate the deviation weighted average penetration distance using the calculated weighted average penetration distance and the weighted average log MF according to the following formula (5), Deviation weighted average permeation distance is used. The method for determining a blended coal composition for coke according to (1) above.

Here, α _i is the blending ratio of coal i of each brand in the survey blended coal, (penetration distance) _i is the penetration distance of coal i of each brand in the survey blend, (logMF) _i Is the log MF of coal i of each brand in the survey coal blend, N is the total number of coal brands constituting the survey coal blend.

Here, a is a common logarithmic value (log MF) of penetration distance and maximum fluidity (MF) of at least one or more coals that can be used as a raw material for coke, which is in a range of 1.0 <log MF <2.5. ) And a regression line passing through the origin from a plurality of sets, the value of the ratio of the change in penetration distance to the change in log MF for the regression line, and the weighted average penetration distance is (3) The weighted average log MF is a value calculated by the formula (4). However, when the value of the right side of the formula (5) is equal to or less than zero, the deviation weighted average penetration distance is calculated. The value is 0.
(4) For the measurement of the penetration distance, coal prepared to a particle size of 2 mm or less was filled into a container with a packing density of 0.8 g / cm ³ to a thickness of 10 mm, and a diameter of 2 mm was formed on the sample. When the sample is heated up to 550 ° C. at a heating rate of 3 ° C./min while applying a load of 50 kPa to the glass beads, the penetration distance of the molten sample that has penetrated into the glass beads is determined. The method for determining a blended coal composition for coke according to any one of (1) to (3) above, characterized in that measurement is performed.
(5) The coke coal according to any one of (1) to (4) above, wherein a parameter related to the carbonization degree of coal is added to the explanatory variable to predict coke strength. Composition determination method.
(6) The coke strength is predicted by adding a parameter related to the carbonization degree of coal and a parameter related to softening and melting property of coal to the explanatory variable, and any one of (1) to (4) above The method for determining a blended coal composition for coke as described in 1.
(7) A blended coal is produced based on the coal brand and content ratio determined by the blended coal composition determination method for coke according to any one of (1) to (6) above, and the blended coal Coke production method to produce coke by dry distillation.

  According to the present invention, the defect structure existing around the softening and melting layer of coal in the coke oven, particularly the effect of cracks existing in the coke layer adjacent to the softening and melting layer, is simulated, and the softening in the coke oven is performed. Based on the softening and melting characteristics of coal with the appropriate reproduction of the restraint conditions around the melt, that is, the penetration distance, which is a measurement that allows evaluation of softening melt penetration into the defect structure, and maximum fluidity By using the property parameters calculated in this way, the strength of coke obtained by dry distillation of the blended coal can be accurately predicted. Therefore, by determining the blending conditions based on the predicted coke strength, coke having a desired strength can be stably produced. Moreover, since it is not necessary to set the quality of the blended coal higher than necessary, the amount of high-grade coal used can be reduced while maintaining the coke strength, and the cost can be reduced.

It is a schematic explanatory drawing which shows an example of the apparatus which measures a softening-melting characteristic, applying a fixed load to the material used by this invention, and the material which has a through-hole in an upper and lower surface. It is a schematic explanatory drawing which shows an example of the apparatus which measures the softening-melting characteristic, keeping the sample and the material which has a through-hole in an upper and lower surface at a fixed volume in this invention. It is a schematic explanatory drawing which shows an example which has a circular through-hole among the materials which have a through-hole in the upper and lower surfaces used by this invention. It is a schematic explanatory drawing which shows an example of a spherical particle filling layer among the materials which have a through-hole in the upper and lower surfaces used by this invention. It is a schematic explanatory drawing which shows an example of a cylindrical packing layer among the materials which have a through-hole in the upper and lower surfaces used by this invention. It is a graph which shows the measurement result of the penetration distance of the coal softening melt measured in the Example. It is a scatter diagram of the predicted value of the present invention based on the predicted value of the conventional method and the weighted average deviation penetration distance and the actual measured value of the tumbler intensity measured in the examples. It is a scatter diagram of the predicted value of the present invention based on the predicted value of the conventional method and the deviation weighted average penetration distance and the actual measured value of the tumbler intensity measured in the examples. It is a scatter diagram of the predicted value and measured value of the coke strength by the coke strength prediction formula obtained by Example 1 of the present invention. It is a scatter diagram of the predicted value and measured value of the coke strength by the coke strength prediction formula obtained by Example 2 of the present invention.

  In order to achieve the above-described object of the present invention, the present inventors can measure the softening and melting characteristics in a state simulating the environment surrounding the softened and melted coal in the coke oven, and show the measured softening and melting characteristics. We conducted extensive research on the relationship between “penetration distance” and coke strength. As a result, there is a difference in the penetration distance used in the present invention even if the blended coal used in the present invention as a softening and melting characteristic index has little difference in the maximum Gieseller flow rate. We found a phenomenon in which the strength of coke produced from coconut was different. The present inventors have focused on this phenomenon and have come up with the idea that in order to predict coke strength, it is possible to predict coke strength more accurately by using the maximum fluidity and penetration distance.

  The advantage of using the penetration distance as an index in predicting coke strength is not only assumed in principle based on the measurement method close to the coke oven conditions, but also the penetration distance to coke strength. It became clear from the result of investigating the influence. In fact, in the process of investigating the effect of penetration distance on coke strength, even if the coal has the same log MF (the common logarithm of the maximum fluidity by the Gisela plastometer method), there is a difference in the penetration distance depending on the brand. It became clear that there was a difference in the effect on coke strength even in the dry distillation experiment in which coke was produced by blending coal with different penetration distances.

  By the way, in the evaluation of the softening and melting characteristics using a conventional Gisela plastometer, it has been considered that coal exhibiting high fluidity has a higher effect of adhering coal particles. On the other hand, when investigating the relationship between infiltration distance and coke strength, when coal with an extremely long infiltration distance is blended, coarse defects are left during coking and a thin pore wall structure is formed. It turned out that it falls compared with the value estimated from the average grade of blended coal. The reason why the coke strength is lower than the expected value is that coal with a too long permeation distance penetrates significantly between surrounding coal particles, and the part where the coal particles existed itself becomes a large cavity and becomes a defect. It is presumed that. In particular, in the evaluation of softening and melting characteristics with a Gieseler plastometer, it was found that the amount of coarse defects remaining in the coke differs depending on the penetration distance in coal that exhibits high fluidity. This relationship was similarly observed for the binder.

The above-mentioned knowledge was obtained for the first time by measuring the penetration distance. Based on the maximum fluidity (MF) and the penetration distance as a technique to complement or substitute the conventional softening and melting property evaluation method. It shows the effectiveness of the present invention for predicting coke strength using calculated property parameters. The method for predicting the coke strength of the present invention is specifically performed as follows.
1. A plurality of coke is produced by dry distillation of a plurality of blended coals (inspection blended coals) with known brands and blending ratios. Before producing a plurality of cokes, indicators such as maximum fluidity (MF) ddpm and permeation distance mm of each of a plurality of brands of coal included in the investigation target blend are measured in advance.
2. The coke strength of the prepared coke is measured. The coke strength can be measured based on the rotational strength test method of JIS K 2151.
3. Based on the measured maximum fluidity (MF) and permeation distance, properties parameters such as a weighted average deviation permeation distance, a weighted average permeation distance, and a weighted average log MF, which will be described later, are calculated.
4). 1. About a plurality of coke obtained from these plurality of blended coals Using the coke strength measured in step 3 as the target variable, From the explanatory variable including the property parameter calculated in step 1 and the objective variable, a regression equation for predicting the coke strength is created.
5. Based on the created regression equation, the coke strength of the coke that is to be produced from the prediction target blend including multiple brands of coal is predicted. Note that when predicting the coke strength, the maximum fluidity (MF) and the permeation distance of each brand of coal in the prediction target blended coal are measured. Based on the measured maximum fluidity (MF) and permeation distance, and the blending ratio of each brand of coal in the predicted blended coal, the above-mentioned property parameters are calculated, and based on the variables including the calculated property parameters. The coke strength predicted from the created regression equation is obtained. The brand and the blending ratio to be blended with the predicted coal blend are determined so that the predicted coke strength falls within a predetermined management range.
Moreover, based on the brand of coal to be blended and the blending ratio determined in this way, blended coal can be produced, and the produced blended coal can be dry-distilled to produce coke.

First, a method for measuring the “penetration distance” for calculating the property parameter including the weighted average deviation penetration distance and the weighted average penetration distance and the weighted average logMF will be described. The permeation distance is a sample obtained by filling a container prepared with a predetermined particle size with a predetermined packing density into a predetermined thickness in a container, and a material having through holes on the upper and lower surfaces is placed on the sample, The sample and the material are heated at a predetermined heating rate to a predetermined temperature equal to or higher than the softening and melting start temperature of the sample in an inert gas atmosphere while applying a constant load or maintaining a constant volume. This is the distance that the molten sample penetrated when it was infiltrated. FIG. 1 is an example of an infiltration distance measuring apparatus used in the present invention, and is an apparatus for heating a coal sample by applying a constant load to a coal sample and a material having through holes on upper and lower surfaces. The lower part of the container 3 is filled with coal to form a sample 1, and 2, which is a material having through holes on the upper and lower surfaces, is arranged on the sample 1. The sample 1 is heated to the softening and melting start temperature or more, the sample is infiltrated into the material 2 having through holes on the upper and lower surfaces, and the permeation distance is measured. Heating is performed in an inert gas atmosphere. Here, the inert gas refers to a gas that does not react with coal in the measurement temperature range, and representative gases include argon gas, helium gas, nitrogen gas, and the like. Note that the penetration distance may be measured by heating the material having coal and the through-holes while maintaining a constant volume. An example of a measuring device for softening and melting characteristics (penetration distance) used in that case is shown in FIG.

  When a constant load is applied to the sample 1 shown in FIG. 1 and the material 2 having through holes on the upper and lower surfaces and the sample 1 is heated, the sample 1 expands or contracts, and the material 2 having the through holes on the upper and lower surfaces is in the vertical direction. Move to. Therefore, it is possible to measure the expansion coefficient at the time of sample penetration through the material 2 having through holes on the upper and lower surfaces. As shown in FIG. 1, an expansion coefficient detecting rod 13 is arranged on the upper surface of a material 2 having through holes on the upper and lower surfaces, a weight 14 for applying a load is placed on the upper end of the expansion coefficient detecting rod 13, and a displacement meter 15 is placed thereon. And measure the expansion rate. The displacement meter 15 may be one that can measure the expansion range (-100% to 300%) of the expansion coefficient of the sample. Since it is necessary to maintain the inside of the heating system in an inert gas atmosphere, a non-contact type displacement meter is suitable, and it is desirable to use an optical displacement meter. The inert gas atmosphere is preferably a nitrogen atmosphere. In the case where the material 2 having through holes on the upper and lower surfaces is a particle packed layer, the expansion coefficient detecting rod 13 may be buried in the particle packed layer, and therefore the material 2 having the through holes on the upper and lower surfaces and the expansion coefficient detecting rod 13. It is desirable to take measures to sandwich the board between the two. The load to be applied is preferably evenly applied to the upper surface of the material having through holes on the upper and lower surfaces arranged on the upper surface of the sample, and 5 to 80 kPa with respect to the area of the upper surface of the material having the through holes on the upper and lower surfaces, It is desirable to apply a pressure of preferably 15 to 55 kPa, most preferably 25 to 50 kPa. This pressure is preferably set based on the expansion pressure of the softened and molten layer in the coke oven, but as a result of examining the reproducibility of the measurement results and the ability to detect the difference in brands in various coals, A somewhat higher value of about 25 to 50 kPa is most preferable as a measurement condition.

  It is desirable to use a heating means that can heat at a predetermined rate of temperature rise while measuring the temperature of the sample. Specifically, an electric furnace, an external heating type that combines a conductive container and high frequency induction, or an internal heating type such as a microwave. When the internal heating method is adopted, it is necessary to devise a method for making the temperature in the sample uniform, and for example, it is preferable to take measures to increase the heat insulation of the container.

  The heating rate is preferably matched with the heating rate of the coal in the coke oven for the purpose of simulating the softening and melting behavior of the coal and the binder in the coke oven. Although the heating rate of coal in the softening and melting temperature range in the coke oven varies depending on the position in the furnace and operating conditions, it is generally 2 to 10 ° C / min, and the average heating rate should be 2 to 4 ° C / min. The most desirable is about 3 ° C./min. However, in the case of coal with low fluidity such as non-slightly caking coal, the permeation distance and expansion are small at 3 ° C./min, which may make detection difficult. It is generally known that the fluidity of coal is improved by rapid heating with a Gisela plastometer. Therefore, for example, in the case of coal with an infiltration distance of 1 mm or less, measurement may be performed with the heating rate increased to 10 to 1000 ° C./min in order to improve detection sensitivity.

  About the temperature range which heats, since the objective is evaluation of the softening and melting characteristic of coal and a binder, what is necessary is just to be able to heat to the softening and melting temperature range of coal and a binder. Considering the softening and melting temperature range of coal and caking material for coke production, a predetermined heating rate in the range of 0 ° C (room temperature) to 550 ° C, preferably in the range of 300 to 550 ° C, which is the softening and melting temperature of coal. You can heat with.

  The material having through holes on the upper and lower surfaces is preferably one that can measure or calculate the transmission coefficient in advance. Examples of the form of the material include an integrated material having a through hole and a particle packed layer. Examples of the integrated material having a through hole include a material having a circular through hole 16 as shown in FIG. 3, a material having a rectangular through hole, and a material having an indeterminate shape. The particle packed layer is roughly divided into a spherical particle packed layer and a non-spherical particle packed layer. The spherical particle packed layer is composed of beads packed particles 17 as shown in FIG. 4, and the non-spherical particle packed layer is not suitable. Examples of the particles include regular particles and filled cylinders 18 as shown in FIG. In order to maintain the reproducibility of the measurement, it is desirable that the transmission coefficient in the material is as uniform as possible and that the calculation of the transmission coefficient is easy in order to simplify the measurement. Therefore, the use of a spherical particle packed bed is particularly desirable for the material having through holes on the upper and lower surfaces used in the present invention. The material having the through holes on the upper and lower surfaces is not particularly specified as long as the shape hardly changes to the coal softening and melting temperature range, specifically up to 600 ° C., and does not react with coal. Moreover, the height should just be sufficient height for the melt of coal to osmose | permeate, and what is necessary is just about 20-100 mm when heating a coal layer of thickness 5-20 mm.

The transmission coefficient of the material having through holes on the upper and lower surfaces needs to be set by estimating the transmission coefficient of coarse defects present in the coke layer. In the case where the transmission coefficient is 1 × 10 ⁸ to 2 × 10 ⁹ m ⁻² as a result of repeated investigations by the present inventors, such as consideration of coarse defect constituent factors and estimation of the size, which are particularly desirable for the present invention. Was found to be optimal. This transmission coefficient is derived based on the Darcy rule expressed by the following equation (6).

ΔP / L = K · μ · u (6)
Here, ΔP is the pressure loss [Pa] in the material having through holes on the upper and lower surfaces, L is the height [m] of the material having the through holes, K is the transmission coefficient [m ⁻² ], μ is the fluid. Viscosity [Pa · s], u is fluid velocity [m / s]. For example, when a glass bead layer having a uniform particle diameter is used as a material having through holes on the upper and lower surfaces, in order to have the above-mentioned preferable transmission coefficient, glass beads having a diameter of about 0.2 mm to 3.5 mm are used. It is desirable to choose, most preferably 2 mm.

The coal and binder used as the measurement sample are pulverized in advance and filled to a predetermined layer thickness with a predetermined packing density. The pulverized particle size may be the particle size of the coal charged in the coke oven (the ratio of particles having a particle size of 3 mm or less is about 70 to 80% by mass), and pulverization is performed so that the particle size of 3 mm or less is 70% by mass or more. However, it is particularly preferable to use a pulverized product in which the total amount is pulverized to a particle size of 2 mm or less in consideration of measurement with a small apparatus. The density for filling the pulverized product can be 0.7 to 0.9 g / cm ³ in accordance with the packing density in the coke oven. As a result of studying reproducibility and detection power, 0.8 g / cm ³ is preferable. I found out. Further, the layer thickness to be filled can be 5 to 20 mm based on the thickness of the softened and melted layer in the coke oven, but as a result of studying reproducibility and detection power, the layer thickness should be 10 mm. preferable.

The penetration distance can be measured under the following typical measurement conditions by using the above-described apparatus and adjusting the measurement conditions.
(A) Coal or caking material is pulverized so that the particle size of 2 mm or less is 100% by mass, and the pulverized coal or caking material has a packing density of 0.8 g / cm ³ and a layer thickness of 10 mm. A sample is prepared by filling the container as described above.
(B) A glass bead having a diameter of 2 mm is placed on the sample so as to have a thickness equal to or greater than the permeation distance (usually a layer thickness of 80 mm).
(C) Heating from room temperature to 550 ° C. in an inert gas atmosphere at a heating rate of 3 ° C./min while applying a load from the top of the glass beads to 50 kPa.
(D) The penetration distance of the molten sample that has penetrated into the glass bead layer is measured.

  Regarding the measurement of the penetration distance (D) above, it is originally desirable that the penetration distance of the softened melt of coal and binder can be continuously measured during heating. However, continuous measurement is difficult due to the influence of tar generated from the sample. The expansion and infiltration phenomenon of coal by heating is irreversible, and once expanded and infiltrated, the shape is maintained even after cooling, so after the coal melt has been infiltrated, the entire container is cooled, You may make it measure how much it penetrate | infiltrated during the heating by measuring the penetration distance after cooling. For example, it is possible to take out a material having through holes on the upper and lower surfaces from the cooled container and directly measure with a caliper or a ruler.

  When particles are used as a material having through holes on the upper and lower surfaces, the softened melt that has permeated the interparticle voids fixes the entire particle layer up to the permeated portion. Therefore, if the relationship between the mass and height of the particle packed bed is obtained in advance, the mass of the non-adhered particles is measured after the infiltration, and the mass of the adhering particles is derived by subtracting from the initial mass. And the penetration distance can be calculated therefrom.

Next, the property parameters used in the present invention will be described. The present inventors repeatedly investigated the relationship between the above-mentioned permeation distance and the maximum fluidity showing the softening and melting characteristics of the coal constituting the coal blend and the coke strength by repeating the carbonization test in the laboratory, and repeated earnest research. As a result, it was found that the following two relationships exist between the permeation distance, maximum fluidity and coke strength.
(1) Create a regression line between the permeation distance and the common logarithm of the maximum fluidity with the penetration variable as the objective variable (Y) and the common logarithm of the maximum fluidity as the explanatory variable (X). On the other hand, when the blended coal is blended with a brand of coal with a larger width (hereinafter referred to as deviation permeation distance) in which the value of the permeation distance is biased in the positive direction, the coke strength of the coke produced from the blended coal descend.
(2) Create a regression line between the penetration distance and the common logarithm of the maximum fluidity, with the penetration distance as the objective variable (Y) and the common logarithm of the maximum fluidity as the explanatory variable (X). On the other hand, the more the brands whose permeation distance values deviate in the positive direction are blended with the blended coal, the lower the coke strength of the coke produced from the blended coal.

  As described above, even if the maximum fluidity is the same, the reason why the strength of the coke is affected by the size of the permeation distance is as follows. (1) The larger the permeation distance, the coarser the defects in the coke after dry distillation. (2) Coarse defects increase in the coke after dry distillation, as more coal with an excessive penetration distance is blended.

  In the conventional coal blending theory for predicting coke strength, coke strength is mainly considered to be determined by the coal's vitrinite average maximum reflectance (Ro) and the logarithmic value (log MF) of the Gieseler maximum fluidity. (For example, refer nonpatent literature 1). On the other hand, according to the present invention, as described in (1) and (2) above, since the maximum fluidity and the penetration distance affect the coke strength, the properties calculated based on the penetration distance and the maximum fluidity. By using parameters as explanatory variables when predicting coke strength, it is possible to make predictions with higher accuracy than before.

  Further, it is desirable that the parameters for predicting the coke strength be in a form reflecting the relationship of (1) and (2) above. As a result of earnestly researching the optimal form for the prediction of coke strength by the infiltration distance as a parameter, the present inventors have determined the weighted average deviation infiltration distance, the weighted average infiltration distance and the weighted average log MF obtained by the following calculation. We have found that it is desirable to use property parameters that include.

  When the present inventors investigated the relationship by measuring the penetration distance and maximum fluidity (MF) for brands having various properties, the common logarithm value of the measured maximum fluidity (MF) was investigated. In the range of 1.0 <log MF <2.5, it was found that both had a good positive correlation. Accordingly, in actual operation, a set of penetration distance and maximum fluidity (MF) of a plurality of brands of coal is measured, and 1.0 <log MF is selected from the measured penetration distance and maximum fluidity (MF) pair. <Penetration distance and maximum fluidity (MF) are extracted from at least one coal in the range of 2.5, and based on the combination of the extracted penetration distance and maximum fluidity (MF), the penetration distance Was the objective variable (Y), and a regression line passing through the origin with the common logarithm of the highest fluidity (log (MF)) as the explanatory variable (X) was created. Next, the deviation between the regression line and the penetration distance of the coal was calculated. The deviation penetration distance of this coal represents the influence of coke strength when the coal is blended with blended coal, and the larger this value, the greater the reduction in coke strength during blending. Equation (1) shows a calculation formula for obtaining the deviation penetration distance of each of the multiple brands of coal from the measured values of the penetration distance and the maximum fluidity of each brand of coal in the blended coal.

  Where a is the maximum fluidity (MF) of any coal used for coke production (coke raw material), and based on the measured maximum fluidity, a range of 1.0 <logMF <2.5 At least one or more coal is extracted, and the penetration distance of the extracted coal is measured. Based on the measured value, the penetration distance is set as the objective variable (Y), and the common logarithm value (logMF) of the maximum fluidity is explained. This is the coefficient (slope) of log MF when a regression line passing through the origin as variable (X) is created. Log MF is a logarithmic value of the maximum fluidity of the coal. However, the lower limit of the value of the deviation penetration distance is 0. The reason why the lower limit is set in this way is that the brand whose permeation distance is negatively biased does not form coarse defects in the coke after dry distillation, so it does not reduce coke strength, but does not improve it. This is due to experimental confirmation.

  The slope a is also the value of the ratio of the amount of change in the penetration distance to the amount of change in logMF for this regression line. Of the measured values of osmotic distance and maximum fluidity, the common logarithm value (logMF) of the maximum fluidity can be the objective variable (Y), and the osmotic distance can be the explanatory variable (X). Even if a regression line passing through the origin is created, the value of the ratio of the change amount of the penetration distance to the change amount of the log MF for the regression line is calculated as a.

  The coke strength obtained by dry distillation of blended coal is affected by the deviation penetration distance and the blending ratio of brands constituting the blended coal. Therefore, the weighted average deviation penetration distance, calculated by weighted average of the deviation penetration distance of the brands constituting the blended coal according to the blending ratio in the blended coal, is included in the explanatory variable of the regression equation when predicting the coke strength. Property parameters. A formula for obtaining the weighted average deviation penetration distance is shown in Formula (2).

Here, α _i is a blending ratio of coal _i of each brand in the blended coal, (deviation penetration distance) _i is a deviation penetration distance of coal _i of each brand in the blended coal, and N is a coal brand constituting the blended coal. The total number of In addition, the described blended coal means a plurality of investigational blended coals whose brands and blending ratios are known.

  Further, the inventors of the present invention substantially match the weighted average penetration distance calculated by weighted average of the penetration distance of the brand constituting the blended coal according to the blending ratio in the blended coal. This is confirmed experimentally. Similarly, it is generally known that the log MF of the blended coal substantially matches the weighted average value. Therefore, it is also effective to use a deviation weighted average infiltration distance value obtained by the following calculation as a property parameter included in the explanatory variable of the regression equation when predicting the strength of coke.

  That is, the weighted average permeation of the following formulas (3) and (4) according to the blending ratio of each brand of coal in the blended coal from the measured values of the penetration distance and maximum fluidity of each brand constituting the blended coal. Calculate the distance and weighted average log MF.

Here, α _i is the blending ratio of coal i of each brand in the blended coal, (penetration distance) _i is the penetration distance of coal i of each brand in the blended coal, and (logMF) _i is each blended coal in the blended coal. The log MF, N of the brand coal i is the total number of coal brands constituting the blended coal. In addition, as the blended coal contains more coal having a large deviation penetration distance, the weighted average penetration distance obtained by the equation (3) is the deviation from the penetration distance obtained by the regression line from the weighted average log MF obtained by the equation (4). Becomes larger. Therefore, this value was used as a property parameter for predicting coke strength, using the deviation weighted average penetration distance of the blended coal. The formula for calculating the deviation weighted average penetration distance is shown in Formula (5).

  A in formula (5) is obtained in the same manner as a described above, and the maximum fluidity (MF) of any coal used for coke production (coke raw material) is measured, and the maximum flow measured. Based on the degree, extract at least one or more coals in the range of 1.0 <log MF <2.5, measure the penetration distance of the extracted coal, and determine the penetration distance based on the measured value as an objective variable ( Y), and the log MF coefficient (slope) when a regression line passing through the origin with the common logarithm of the maximum fluidity (log MF) as the explanatory variable (X) is created. The weighted average penetration distance and the weighted average log MF are values calculated by the equations (3) and (4), respectively. However, when the value on the right side of equation (5) is less than or equal to zero, the value of the deviation weighted average penetration distance is set to zero.

  The formula (5) is mathematically equivalent to the formula (2), and the weighted average value is calculated without setting the value to 0 even when the deviation penetration distance is a negative value in the formula (1). Matches. As mentioned above, brands that have a negative deviation penetration distance do not have the effect of improving the strength of the blended coal, but the inventors have applied weighted average deviation penetration distance and deviation weighted average penetration for various blended coals. As a result of investigating the relationship between distances, it has been confirmed that there is a practically sufficient correlation between the two. This is because there is almost no coal that has a large penetration distance with respect to the regression line (coal in which the right side of equation (1) has a large negative value), and even if it is negatively biased, This is because the value is as small as about 3 mm at most. Therefore, even if the deviation weighted average penetration distance is used, it is possible to perform prediction with sufficiently higher accuracy than conventional coke strength prediction.

  Moreover, when calculating using Formula (2), you may calculate by making the deviation penetration distance of the coal in the range of logMF <2.5 into 0. This is because, in the case of coal in this property range, the penetration distance does not deviate greatly from the regression equation, and low MF coal is relatively affected by measurement errors because the absolute value of the penetration distance is small. It is easy and tends to reduce the prediction accuracy. In addition, when the strength influence of blended coal was investigated using the coal in this property range, it was experimentally confirmed that the difference in the permeation distance did not greatly affect the strength.

  The feature of the present invention is that a characteristic parameter derived from the maximum fluidity (MF) and the penetration distance is used as an explanatory variable for predicting the coke strength. Coal used for blended coal is usually used by measuring various grades for each brand in advance. Similarly, the maximum fluidity (MF) and permeation distance may be measured in advance for each brand lot. Here, since the value of the penetration distance may vary depending on the measurement conditions, measurement is performed under the same conditions for all coals, and the value is used for prediction of coke strength.

  Moreover, you may add the parameter regarding another coal property to the explanatory variable of the regression line whose objective variable is coke strength. In particular, parameters related to the carbonization degree of coal and parameters related to the softening and melting property of coal are important in predicting the strength of coke. Examples of parameters related to the carbonization degree of coal include the reflectivity, volatile content, carbon content, and calorific value of coal, and examples of parameters related to softening and melting characteristics are obtained from the Gieseler maximum fluidity and dilatometer. Values such as expansion coefficient, dynamic viscoelasticity, expansibility, and specific volume are known. Particularly preferred is the addition of the average maximum reflectance of coal vitrinite and the highest Gieseller fluidity to the penetration distance, to the explanatory variable of the regression equation where the objective variable is coke strength. In addition, a combination of other coal property indicators such as inert content, coal preconditions such as coal particle size and moisture content, and coke oven dry distillation conditions, etc. You may add to.

  As described above, a weighted average deviation penetration distance or an explanatory variable including a property parameter that is a deviation weighted average penetration distance is used, and a prediction formula for coke strength with coke strength as a target variable is created in advance, and the predicted strength is By determining the blending ratio of the blended coal so as to be in the control range, it becomes possible to determine the brand and content ratio of the coal contained in the blended coal that is the base of the coke having the strength of the desired control range. . As a result, coke having a strength within a desired management range can be stably produced.

  For 26 types of coal (A to Z charcoal), for example, indicators indicating the properties of the coal such as permeation distance were measured. Table 1 shows the properties of the coal used. Here, Ro is the average vitrinite average reflectance of coal according to JIS M 8816, log MF is the common logarithm of the maximum fluidity (Maximum Fluidity: MF) measured by the Giesera plastometer method, volatile matter (VM), ash content (Ash) ) Is a measured value (dry base) according to the industrial analysis method of JIS M 8812. TI is a ratio of an inert component that does not exhibit softening and melting properties during dry distillation, calculated based on a method for measuring a microstructure component of coal according to JIS M 8816.

  The penetration distance was measured using the apparatus shown in FIG. Since the heating method was a high frequency induction heating type, the heating element 8 in FIG. 1 was an induction heating coil, and the material of the container 3 was graphite, which is a dielectric. The diameter of the container was 18 mm, the height was 37 mm, and glass beads with a diameter of 2 mm were used as materials having through holes on the upper and lower surfaces. The sample 1 was filled by loading 2.04 g of a coal sample pulverized to a particle size of 2 mm or less and vacuum-dried at room temperature into the container 3 and dropping a weight of 200 g from the top of the coal sample 5 times at a fall distance of 20 mm. (In this state, the sample layer thickness was 10 mm). Next, glass beads having a diameter of 2 mm were placed on the packed layer of Sample 1 so as to have a thickness of 25 mm. A sillimanite disk having a diameter of 17 mm and a thickness of 5 mm is placed on the glass bead packed layer, a quartz rod is placed thereon as the expansion coefficient detecting rod 13, and a weight of 1.3 kg is placed on the quartz rod. placed. As a result, the pressure applied on the sillimanite disk is 50 kPa. Nitrogen gas was used as the inert gas, and the mixture was heated to 550 ° C. at a heating rate of 3 ° C./min. After the heating, cooling was performed in a nitrogen atmosphere, and the mass of beads not fixed to the softened and melted coal was measured from the cooled container. In addition, although said measurement conditions are what the inventors determined as measurement conditions of a preferable penetration distance by the comparison of the measurement result on various conditions, a penetration distance measurement is not restricted to this method.

  In addition, what is necessary is just to arrange | position so that the thickness of a glass bead layer may become layer thickness more than an osmosis | permeation distance. If the melt has penetrated to the top of the glass bead layer during measurement, the glass beads are increased and remeasured. The inventors conducted a test in which the layer thickness of the glass beads was changed, and confirmed that the permeation distance measurement values of the same sample would be the same if there was a glass bead layer thickness greater than or equal to the penetration distance.

  The permeation distance was determined by the filling height of the fixed bead layer. The relationship between the filling height and the mass of the glass bead packed bed was obtained in advance, and the glass bead filling height could be derived from the mass of the beads to which the softened and melted coal was fixed. The result is Equation (7), and the penetration distance was derived from Equation (7).

L = (GM) × H (7)
Here, L is the penetration distance [mm], G is the mass of the filled glass beads [g], M is the mass of the beads not fixed to the softened melt [g], and H is the glass beads filled in this experimental apparatus. It represents the height of the packed bed per gram [mm / g].

  The measurement results of the penetration distance are also shown in Table 1. Further, FIG. 6 shows the relationship between the measurement results of the osmosis distance and the logarithmic value (logMF) of the Gieseler maximum fluidity. From FIG. 6, the penetration distance measured in this example was correlated with log MF, but it was confirmed that there were brands with different penetration distances even with the same log MF. In particular, this tendency was observed in a region where log MF was high. Considering that the measurement error of the penetration distance in this device was a standard deviation of 0.6 as a result of three tests under the same conditions, the penetration distance was different for coal A and coal K with the same log MF. Significant differences were observed.

  Next, in order to examine the effectiveness when the penetration distance of the present invention is applied to the method for predicting the coke strength, blended coal (2 brands blended at a mass ratio of 1: 1) using the coal of Table 1 is prepared. Then, the coke strength after the carbonization was measured. Table 2 shows property values of the blended coal. Table 2 also shows the weighted average deviation penetration distance calculated by the equation (2) and the deviation weighted average penetration distance calculated by the formula (5). Here, the constant a in the formula (1) and the formula (5) is based on the coal penetration distance and the maximum fluidity in the range of 1.0 <log MF <2.5 among the coals in Table 1. The slope of the regression line was calculated and determined to be 2.977.

The carbonization of the blended coal was performed as follows. Moisture coal blend described in Table 2 was adjusted to 6 mass%, the coal blend 6 kg, was charged into the carbonization can so that the bulk density of 775 kg / ^{m 3,} carrying a weight of 4.8kg thereon In this state, the carbonization was carried out in an electric furnace with a furnace wall temperature of 1050 ° C. for 4 hours and 20 minutes, then taken out of the furnace and cooled with nitrogen to obtain coke. The coke strength of the obtained coke was measured based on the rotational strength test method of JIS K 2151 by measuring the mass ratio of coke having a particle size of 6 mm or more after 400 rpm and 400 rpm, and the mass ratio with the tumbler strength TI400 / Calculated as 6. The measurement results of the tumbler strength are also shown in Table 2.

  Next, the coke strength was predicted from the property value of the blended coal by multiple regression analysis. In the conventional coal blending theory for predicting coke strength, it is considered that the coke strength is mainly determined by the vitrinite average maximum reflectance (Ro) of coal and log MF. Further, it is generally known that the ratio of the inert structure affects the coke strength (for example, Non-Patent Document 2). Therefore, as a conventional method for predicting coke strength, the tumbler strength obtained in this test was used as an objective variable, and Ro, log MF, and TI were used as explanatory variables, and a correlation coefficient was obtained (comparative example). As a result, the following regression equation (8) was obtained.

TI (400/6) = 78.35 + 7.267 × Ro + 0.054 × log MF−0.076 × TI (8)
Further, Table 3 shows the obtained correlation coefficient and the degree of freedom adjusted correlation coefficient.

Similarly, in order to predict the coke strength based on the present invention, the tumbler strength obtained in this test was used as an objective variable, and Ro, log MF, TI, and the weighted average deviation penetration distance were used as explanatory variables, and multiple regression was performed. The number of relationships was determined (Invention Example 1). As a result, the following regression equation (9) was obtained.
TI (400/6) = 75.01 / 10.11 × Ro + 0.870 × log MF−0.124 × TI−0.293 × weighted average deviation penetration distance (9)
Using the deviation weighted average permeation distance as an explanatory variable, multiple regression was performed in the same manner as in Invention Example 1 to obtain the following regression equation (10) (Invention Example 2).
TI (400/6) = 75.05 + 10.20 × Ro + 0.850 × log MF−0.129 × TI−0.284 × deviation weighted average penetration distance (10)
In the equations (8) to (10), Ro, logMF, and TI are a weighted average vitrinite average maximum reflectance, a weighted average logMF, and a weighted average TI, respectively, of the blended coal.

  Table 3 also shows the correlation coefficient obtained by each multiple regression and the correlation coefficient adjusted for the degree of freedom. Further, FIG. 7 shows a scatter diagram of the predicted value of the present invention and the actually measured value based on the predicted value of the conventional method and the weighted average deviation penetration distance. In addition, FIG. 8 shows a scatter diagram of the predicted value and the actual measurement value of the present invention based on the predicted value of the conventional method and the deviation weighted average penetration distance.

  From Table 3, FIG. 7 and FIG. 8, the coke strength prediction formula according to the present invention has a higher correlation coefficient than the conventional coke strength prediction formula, and the conventional coke strength measured with the blended coal of Table 2 is conventional. It can be seen that this is a prediction formula with fewer errors than the above prediction formula.

  Next, the coke strength after dry distillation of the coal blends listed in Table 4 was predicted using equations (8) to (10), and the accuracy of each prediction equation was verified. The coke dry distillation method and the strength measurement method are the same as the methods implemented in the preparation of the prediction formula for the coke strength.

  FIG. 9 shows a scatter diagram of the predicted value obtained by carrying out the comparative example according to the formula (8) and the predicted value obtained according to the formula (9) obtained by carrying out the present invention example 1 and the actual measured value. In addition, FIG. 10 shows a scatter diagram of the predicted value based on the formula (8) and the predicted value based on the formula (10) obtained by carrying out the present invention example 2 and the actually measured value. Table 5 shows the correlation coefficient obtained from each scatter diagram.

  From Table 5, FIG. 9, and FIG. 10, it was confirmed that the prediction formula of coke strength according to the present invention has a higher correlation coefficient and improved prediction accuracy than the conventional prediction formula of coke strength. Therefore, the prediction method according to the present invention is very effective as compared with the prior art.

In the example of the present invention, a prediction example of tumbler strength is shown as an example of a method for predicting the rotational strength of coke, but prediction of JIS drum strength, Mycam strength, and ASTM strength can also be performed based on the same principle. Furthermore, if the reactivity of coke is taken into consideration, it is possible to predict CSR (coke strength after CO ₂ reaction).

DESCRIPTION OF SYMBOLS 1 Sample 2 Material which has a through-hole in the upper and lower surfaces 3 Container 4 Pressure detection rod 5 Sleeve 6 Load cell 7 Thermometer 8 Heating element 9 Temperature detector 10 Temperature controller 11 Gas inlet 12 Gas outlet 13 Expansion coefficient detection rod 14 Weight DESCRIPTION OF SYMBOLS 15 Displacement meter 16 Circular through-hole 17 Packing particle 18 Packing cylinder 20 Porous wall 21 Porous

Claims (6)

A coke blending coal composition determining method for determining a composition of coke blended coal produced by dry distillation of blended coal containing multiple brands of coal,
Measure coke strength of coke prepared from survey coal blend containing multiple brands of coal, and maximum fluidity (MF) ddpm and permeation distance of each of the multiple brand coals included in the survey coal blend measure mm,
With the measured coke strength as the objective variable, the explanatory variable including the property parameter calculated based on the maximum fluidity (MF) and the permeation distance and the objective variable, from the prediction target blended coal including multiple brands of coal Create a regression equation to predict the coke strength of the coke to be produced, predict the coke strength of the coke to be produced based on the regression equation,
A coke blending coal composition determining method for determining a coal brand and a blending ratio of a plurality of brands included in the prediction target blended coal so that the predicted coke strength is in a predetermined management range ,
From the following formula (1), the deviation penetration distance of each brand coal in the survey coal blend is calculated from the measured value of the penetration distance and maximum fluidity of each brand coal in the survey blend coal,
The following formula (2) is used to calculate the weighted average deviation penetration distance obtained by weighted averaging the deviation penetration distance of each brand of coal according to the blending ratio of each brand of coal in the surveyed blended coal. ,
The blended coal composition determination method for coke, wherein the weighted average deviation penetration distance is used as the property parameter.

Here, a is a common logarithmic value (log MF) of penetration distance and maximum fluidity (MF) of at least one or more coals that can be used as a raw material for coke, which is in a range of 1.0 <log MF <2.5. ) And a regression line passing through the origin from a plurality of sets, the value of the ratio of the change amount of the penetration distance to the change amount of log MF for the regression line,
The permeation distance is the permeation distance of each brand of coal in the investigational blended coal,
logMF is a common logarithm of the maximum fluidity, provided that the value of the deviation permeation distance is 0 when the value on the right side of the equation (1) is less than or equal to zero.

Here, α _i is the blending ratio of each brand of coal _{i in} the surveyed blended coal ,
(Deviation penetration distance) _i is a deviation penetration distance of coal _i of each brand in the investigation target blended coal ,
N is the total number of coal brands constituting the survey coal blend. A coke blending coal composition determining method for determining a composition of coke blended coal produced by dry distillation of blended coal containing multiple brands of coal,
Measure coke strength of coke prepared from survey coal blend containing multiple brands of coal, and maximum fluidity (MF) ddpm and permeation distance of each of the multiple brand coals included in the survey coal blend measure mm,
With the measured coke strength as the objective variable, the explanatory variable including the property parameter calculated based on the maximum fluidity (MF) and the permeation distance and the objective variable, from the prediction target blended coal including multiple brands of coal Create a regression equation to predict the coke strength of the coke to be produced, predict the coke strength of the coke to be produced based on the regression equation,
A coke blending coal composition determining method for determining a coal brand and a blending ratio of a plurality of brands included in the prediction target blended coal so that the predicted coke strength is in a predetermined management range ,
From the measured values of the penetration distance and maximum fluidity of each brand of coal in the surveyed blended coal, the following formulas (3) and (4) are set according to the blending ratio of each brand of coal in the surveyed blended coal. The weighted average penetration distance and the weighted average log MF of
The deviation weighted average penetration distance is calculated using the weighted average penetration distance and the weighted average logMF calculated according to the following formula (5):
A method of determining a blended coal composition for coke, wherein a deviation weighted average permeation distance is used as the property parameter.

Here, α _i is a blending ratio of each brand of coal i in the blended coal to be investigated,
(Penetration distance) _i is the penetration distance of coal i of each brand in the investigational blended coal,
(Log MF) _i is a log MF of each brand of coal i in the investigational blended coal,
N is the total number of coal brands constituting the survey coal blend.

Here, a is a common logarithmic value (log MF) of penetration distance and maximum fluidity (MF) of at least one or more coals that can be used as a raw material for coke, which is in a range of 1.0 <log MF <2.5. ) And a regression line passing through the origin from a plurality of sets, the value of the ratio of the change amount of the penetration distance to the change amount of log MF for the regression line,
The weighted average penetration distance is a value calculated by equation (3),
The weighted average log MF is a value calculated by the equation (4). However, when the value of the right side of the equation (5) is equal to or less than zero, the value of the deviation weighted average penetration distance is zero. For the measurement of the penetration distance, coal prepared to a particle size of 2 mm or less is packed into a container with a packing density of 0.8 g / cm ³ to a thickness of 10 mm, and a glass bead with a diameter of 2 mm is placed on the sample. When the sample is heated to 550 ° C. at a heating rate of 3 ° C./min while applying a load of 50 kPa to the glass beads, the penetration distance of the molten sample that has penetrated into the glass beads is measured. The method for determining a blended carbon composition for coke according to claim 1 or 2 , wherein: The method for determining a blended coal composition for coke according to any one of claims 1 to 3 , wherein a coke strength is predicted by adding a parameter related to the carbonization degree of coal to the explanatory variable. The coke strength according to any one of claims 1 to 3 , wherein coke strength is predicted by adding a parameter related to the carbonization degree of coal and a parameter related to softening and melting property of coal to the explanatory variable. Method for determining the blended coal composition. A blended coal is produced based on the brand and content ratio of coal determined by the method for determining the blended coal composition for coke according to any one of claims 1 to 5 , and the blended coal is subjected to dry distillation to coke. Coke manufacturing method to manufacture.