KR20110124289A - Method of determining dilatation of coal, method of estimating specific volume of coal, method of determining degree of space filling, and method of coal blending - Google Patents

Abstract

In the method for measuring the expansion rate of coal, coal is introduced into the tubules, a piston is inserted into the tubules, and the coals are heated so that the temperature increase rate at the time of softening of the coals is 6 ° C / min or more, The amount of displacement is measured, and the expansion rate of the coal is obtained from the amount of displacement.

Description

METHOD OF DETERMINING DILATATION OF COAL, METHOD OF ESTIMATING SPECIFIC VOLUME OF COAL, METHOD OF DETERMINING DEGREE OF SPACE FILLING, AND METHOD OF COAL BLENDING}

TECHNICAL FIELD The present invention relates to a method for measuring the coefficient of expansion of coal, a method for estimating the cost of coal, a method for measuring the void filling degree, and a coal blending method, which is an evaluation parameter for softening melting characteristics of coal.

This application is Japanese Patent Application No. 2009-056920 for which it applied to Japan on March 10, 2009, and Japan Patent Application No. 2009-173075 for which it applied in Japan on October 24, 2009, and October 16, 2009. On the day, priority is claimed based on Japanese Patent Application No. 2009-239098 for which it applied to Japan, and the content is taken in here.

Blast furnace coke is manufactured by mix | blending many kinds of coal normally according to the required quality of blast furnace, and distilling in a coke oven. When the strength of the blast furnace coke is low, when coke is charged into the blast furnace, the movement (rising) of the reducing gas in the blast furnace is prevented by the powder coke generated from the coke. In this case, the reduction reaction of iron ore is inhibited, and stable operation of the blast furnace becomes difficult. Therefore, blast furnace coke is requested | required to have intensity | strength more than a predetermined value.

As the coke strength, a rotational strength index or a drop strength index such as a drum strength index of JIS (for example, DI ¹⁵⁰ ₆ or DI ¹⁵⁰ ₁₅ ), a microcomputer strength index of ISO, a tumbler strength index of ASTM, and the like are used. All of these indices indicate the degree to which the state of lump coke is maintained without generating powder coke when a predetermined mechanical impact is given to the coke (lump coke). The rotational strength index is obtained by automatically repeating the drop test of coke in a cylindrical container. For this reason, this rotational strength index is essentially the same as the dropping strength index.

When changing the mix of coal, in order to manufacture coke more than predetermined intensity (target value), it is necessary to estimate coke strength from the characteristic of the various coals mix | blended previously. Therefore, the technique which estimates coke strength from the characteristic of the various coals mix | blended has been developed, and many conventional methods have estimated coke strength from the coalization degree and caking property which are the characteristics of coal. As an index indicating the degree of coalification of coal, volatile matter, reflectance, carbon content rate, and the like are used. In addition, as an index indicating coal coking property, expandability (for example, expansion ratio or cost), fluidity, and the like defined in JIS M 8801 are used.

In addition, for example, a method of estimating coke strength by calculating two parameters corresponding to coalization and coking property from an analysis value of coal structure, and two parameters corresponding to coalization and coking property from an elemental analysis value are calculated and coke strength. A method of estimating was also developed. However, in these conventional methods, coke strength cannot be estimated with sufficient precision, for example, when the coal (coal in mixed coal) used is drastically changed.

Patent Literature 1 calculates the void filling at the time of coal softening from the product of the cost of coal softening and the bulk density of coal at the time of coking furnace charging, and estimates the surface breaking strength of the coke from the void filling at the time of coal softening. A method is disclosed.

The method of this patent document 1 is based on the following knowledge. If the expansion rate of coal is high with respect to the porosity between coal particles at the time of coal softening, coal particle cannot fully expand. In contrast, if the expansion ratio is low with respect to the porosity between the coal particles, there are sufficient voids, so the coal particles are freely expanded. When the coal particles freely expand during coal softening, the bubbles in the coal particles burst, producing coarse connecting pores and non-bonding portions between the coal particles, thereby producing fragile coke. The normal coke coal is softened at a temperature of about 400 ° C and starts to expand, and is stocked at a temperature of about 500 ° C. Therefore, if the ratio of coal particles filling the voids from the softening of the coal to the inventory (during coking) is obtained, the amount of defects in the non-adhesive grain boundary and the connecting pores in the coke can be predicted, thereby destroying the surface of the coke. Intensity can be estimated.

Japanese Patent Application Laid-Open No. 2002-121565

In recent years, however, the use of low cohesive coal, which has not been used as a raw material for the coke, has been demanded against the background of rising coal prices. Specifically, for coke production, the use of low cohesive coal (extreme low overall expansion rate coal) whose total expansion rate measured by the expansion test method of JIS M 8801 is 0% is calculated | required. For example, the low-coking coal whose total expansion rate is 0% was used by burning in a boiler as a fuel.

In the method of estimating coke strength of Patent Document 1, it is not considered to use coal whose total expansion ratio is 0%. Therefore, it was unclear whether this method could be used even when using coal whose total expansion rate was 0%. Therefore, the present inventors estimated the intensity | strength of the coke manufactured from the coal blend which contains the coal whose total expansion rate is 0% based on the method of patent document 1. In addition, the coke strength of the blast furnace coke manufactured by distilling the coal briquettes containing the coal whose total expansion rate mentioned above is 0% was measured. The measured coke strength was then compared to the estimated coke strength.

In Table 1, the value of the evaluation parameter which evaluates the softening melting characteristic of coal A-G is shown. Further, coals A to G are coals of different items. Coals A and B are coals having high caking properties, and coals C to G are coals having low caking properties having a total expansion ratio of 0%.

Here, as described in Patent Literature 1, the cost V (cm 3 / g) at the time of coal softening is expressed by the following mathematical expression using the coal volume ΔV (cm 3) at the maximum expansion or the expansion rate b (%) of coal. It is calculated | required from Formula 1 or Formula (2).

In addition, w is the amount of coal loading (g) to an expansion system (tubing). In addition, the coal volume (DELTA) V and the expansion rate b of coal at the time of maximum expansion are measured by an expansion system.

From Equation 2, it can be seen that the coals having the same expansion ratio b have the same cost V at the time of coal softening. In addition, as disclosed in Patent Document 1, the void filling at the time of coal softening can be obtained by multiplying the cost V at the time of coal softening by the bulk density of the coal at the time of charging the coke oven. Moreover, this void filling and coke strength (for example, surface fracture strength) have some correlation. Therefore, the coal of cost V (cm 3 / g) at the same coal softening has the same void filling degree (−) and therefore has the same coke strength.

Thus, the present inventors have found that, by the dry distillation type different formulation Tan X ₁ to X _10, a coke oven, and measured the coke strength DI (index drum). The measurement results are shown in Tables 2 and 3. In addition, with appropriately correlation of these formulation Tan X ₁ to X ₁₀ pores filled help coke strength of DI in Fig. In addition, as a cost of the coal blend X <_1> -X <_10> , the weighted average value of the cost of each coal of Table 1 was used. Data of a black square is the first comparative example using the formulation Tan X ₁ to X ₅ corresponding to the Table 2 below. Data of the white triangle is a second comparative example in which the blended carbon X ₆ to X ₁₀ corresponding to, Table 3. The

In addition, while Table 2 and Table 3 shows the compounding ratio of coal A to G used in the formulation Tan X ₁ to X _10. That is, in the formulation Tan X _1, is as an 25% by weight coal A, with a 25% by weight coal B, 50 mass% coal C formulation. Formulation Tan X _2, there is with 25% by weight coal A, and of 25 mass% coal B, 50 mass% coal D formulation. Formulation Tan X _3, there is a 25% by weight of the coal A, B and coal, and 50% by mass of 25 mass% coal E formulation. Blending carbon X ₄ is, with a 25% by weight coal A, and is 25 mass% coal B, 50 mass% coal is blended F. Formulation Tan X _5, there are a coal-A of 25% by weight, the coal B and of 25% by mass, 50% by weight of coal G formulation.

Further, the formulation Tan X _6, is of 50% by weight coal and A, and 50% by weight coal-C in combination. Formulation Tan X _7, there as a 50 wt% coal A, a 50% by weight coal D are blended. Formulation Tan X _8, there is a 50% by weight of the coal A, 50 mass% coal E formulation. Formulation Tan X _9, there is a 50% by weight of the coal A, 50 mass% coal F formulation. Blending carbon, the X _10, and has a 50% by weight coal A, 50 mass% coal is G in combination.

In the blended coals X ₁ to X ₅ , all of the void fillings at the time of softening of the coal blends are the same. Accordingly, from the above description, it is considered to jindago same from all the coke strength DI using the formulation Tan X ₁ to X _5. Similarly, in the coal briquettes X ₆ to X ₁₀ , all of the pore filling degrees of the coal blend are the same. Accordingly, from the above description, it is considered formulation Tan X ₆ to the coke strength DI FIG jindago to all the same with X _10.

However, as shown in Table 2, the coke strength DI with each formulation Tan X ₁ to X ₅ is different from each other. Similarly, as shown in Table 3, each formulation is also burnt X ₆ to X ₁₀ with the coke strength DI, they are different from each other. Therefore, when coke was manufactured using the coal briquettes containing the coal whose total expansion rate is 0%, it turned out that the estimation method of the coke strength of patent document 1 is not applicable.

Therefore, this invention provides the measuring method of expansion rate (or cost-effectiveness) applicable also to the coal whose total expansion rate is 0%. It also provides a cost estimating method that can be applied to blended coal containing coal having a total expansion ratio of 0%. Moreover, the measuring method of the void filling degree which can be applied also to the coal briquettes containing the coal whose total expansion rate is 0% is provided. In addition, the coal blending method using the measuring method of the void filling degree which is applicable also to the coal briquettes containing the coal whose total expansion rate is 0% is provided.

This invention employ | adopted the following means in order to provide the measuring method of expansion rate applicable also to coal which is 0% of total expansion rate.

(1) In the method for measuring the coefficient of expansion of coal according to the present invention, coal is placed in a tubule, a piston is inserted into the tubule, and the coal is heated so that the temperature increase rate at the time of softening of the coal is 6 ° C / min or more. The displacement amount of the piston is measured, and the expansion rate of the coal is obtained from this displacement amount.

(2) In the measuring method of the expansion rate of coal as described in said (1), conditions other than the said temperature increase rate may be according to the expansion test method of JIS M 8801.

(3) In the measuring method of the expansion rate of coal as described in said (1), conditions other than the said temperature increase rate may be according to the expansion test method of ISO 8264.

(4) In the measuring method of coal expansion rate as described in said (1), the said coal may be ultra-low total expansion rate coal whose total expansion rate measured by the expansion test method of JISM 8801 is 0%.

In addition, the present invention employs the following means in order to provide a cost-effective estimation method that can be applied to coal (extreme low overall expansion rate coal) having an overall expansion rate of 0%.

(5) In the cost estimation method at the time of coal softening of this invention which estimates the cost at the time of coal softening of the ultra-low overall expansion rate coal whose total expansion rate measured by JIS M 8801 coal expansion test method is 0%, The relationship between the standard cost-effectiveness at the time of softening of the said ultra-low overall expansion rate coal calculated | required from the expansion rate of the coal measured by the measuring method of the expansion rate of coal described in 1), and the standard oxygen concentration of the said ultra low overall expansion rate coal are calculated | required in advance to this relationship. The cost of the coal softening of the ultra low overall expansion coal is estimated from the oxygen concentration of the ultra low overall expansion coal measured on the basis of this.

(6) In the cost estimation method at the time of coal softening as described in said (5), the said oxygen concentration of the said ultra-low overall expansion rate coal may be 9 mass% or more.

(7) In the cost estimation method at the time of coal softening as described in said (5), the said oxygen concentration of the said ultra-low overall expansion rate coal may be 12 mass% or less.

Moreover, this invention employ | adopted the following means in order to provide the measuring method of the void filling degree which can be applied also to the coal briquettes containing the coal of 0% of total expansion rate.

(8) In the method for measuring the void filling degree of the present invention, the expansion rate of the coal is measured using the method for measuring the expansion rate of coal according to the above (1), and from this expansion rate, the cost of the softening of the coal is obtained. This cost value is multiplied by the bulk density at the time of charging the coke of the coal to obtain the void filling degree at the time of softening of the coal.

(9) In the measuring method of the void filling degree as described in said (8), the said coal may be ultra-low total expansion rate coal whose total expansion rate measured by the expansion test method of JISM 8801 is 0%.

(10) In the method for measuring the void filling degree of the present invention, a plurality of coals are prepared, and the method for measuring the expansion ratio of coal described in the above (1) is applied to at least one of the coals. The cost cost at the time of softening of coal is calculated | required, the weight average of the said cost at the time of softening of each said coal is calculated | required by making the compounding ratio of each said coal as a weight, and the average cost cost of the coal blended is calculated | required, and the average cost at the time of charging with coke By multiplying the bulk density of the blended coal, the filling degree of voids during softening of the blended coal is obtained.

(11) In the measuring method of the void filling degree as described in said (10), the said coal briquettes may also contain the ultra-low total expansion rate coal whose total expansion rate measured by the expansion test method of JISM 8801 is 0%.

(12) In the method for measuring the porosity filling of the present invention, the ultra-low overall expansion rate in which the total expansion rate measured by the expansion test method of JIS M 8801 is 0% using the cost estimating method of coal according to (5) above. The cost at the time of softening of a coal is calculated | required, and this cost value is multiplied by the bulk density at the time of charging the coke oven of the said extremely low total expansion rate coal, and the void filling at the time of softening the said ultra low total expansion rate coal is calculated | required.

(13) In the method for measuring the void filling degree of the present invention, a plurality of coals including extremely low total expansion coefficient coal having a total expansion ratio of 0% as measured by the coal expansion test method according to JIS M 8801 are prepared, and each coal Among these coals, the cost estimate for the softening of the coals is obtained by applying the cost estimation method of coal according to (5) to the ultra-low overall expansion coefficient coal, The weighted average of the above-mentioned costs at the time of softening is obtained, and the average cost of the mixed coal is calculated by multiplying the average cost by the bulk density of the above-mentioned coal at the time of charging the coke oven to obtain the void filling at the time of softening the above-mentioned coal.

(14) In the measuring method of the void filling degree as described in said (12) or (13), 9 mass% or more of oxygen concentration of the said ultra-low overall expansion rate coal may be sufficient.

(15) In the measuring method of the void filling degree as described in said (12) or (13), the oxygen concentration of the said ultra-low overall expansion rate coal may be 12 mass% or less.

The present invention employs the following means in order to provide a coal blending method that can be applied to blended coal containing coal having a total expansion ratio of 0%.

(16) In the coal blending method of the present invention, a plurality of coals are prepared, and the method of measuring the expansion ratio of coal described in the above (1) is applied to at least one of the coals to soften the coals. The average cost of coal blended coal is calculated | required by calculating | requiring the cost cost of the city, making the compounding ratio of each said coal a weight, and weighting-averaging the said cost cost at the time of softening of each said coal. By multiplying the bulk density of the mixture, the pore filling at the time of softening of the coal briquettes is obtained, and based on the relationship between the standard pore filling at the time of softening of the coal briquettes and the standard coke strength of the coke produced from the coal briquettes, The coke strength of the coke using the blended coal is estimated from the pore filling at the time of softening the blended coal, and the phase of the coke using the blended coal is estimated. And the formulation of each coal coke strength so as to be equal to or greater than a predetermined value.

(17) In the coal blending method described in the above (16), the coal blend may include an extremely low total expansion coefficient coal having a total expansion ratio of 0% as measured by the expansion test method of JIS M 8801.

(18) In the coal blending method of the present invention, a plurality of coals including extremely low total expansion coefficient coal having a total expansion ratio of 0% as measured by the coal expansion test method of JIS M 8801 is prepared, Applying the cost estimation method of coal as described in said (5) with respect to ultra-low overall expansion rate coal, the cost at the time of softening of each said coal is calculated | required, and the compounding rate of each said coal as a weight, The average cost of coal blended carbon is obtained by weighted-averaging the cost, and the average cost is multiplied by the bulk density of the coal blended at the time of coke oven charging to obtain the void filling at the time of softening the blended coal. The pore filling at the time of softening of the coal briquettes, based on the relationship between the standard pore filling at the time of softening of the coal and the standard coke strength of the coke produced from the blended coal. Estimate the coke strength of the coke with the blended carbon from the road, and then blended with each of the coal which the coke strength of the coke with the carbon formulation such as greater than or equal to a predetermined value.

(19) In the coal compounding method as described in said (18), 9 mass% or more of oxygen concentrations of the said ultra-low overall expansion rate coal may be sufficient.

(20) In the coal mixing method as described in said (18), the oxygen concentration of the said ultra-low overall expansion rate coal may be 12 mass% or less.

According to the present invention, it is possible to measure the expansion ratio (expensive) and the void filling degree so that coal having a total expansion ratio of 0% measured by the expansion test method of JIS M 8801 can be distinguished. In addition, it is possible to easily estimate the cost of coal having a total expansion ratio of 0%. Further, according to the present invention, coke strength can be easily and accurately estimated at the time of coal mixing, so that a suitable mixing ratio of coal can be determined.

1 is a relationship diagram showing a relationship between a heating temperature and a displacement amount of a piston.
FIG. 2 is a correlation diagram showing the relationship between the void filling and coke strength DI shown in Tables 5 and 6. FIG.
3 is a correlation diagram showing the relationship between the void filling and coke strength DI shown in Tables 8 and 9. FIG.
4 is a correlation diagram showing the relationship between the pore filling and the coke strength DI shown in Tables 2 and 3. FIG.
FIG. 5 is a correlation diagram showing the relationship between the void filling and coke strength DI shown in Tables 10 and 11. FIG.
6 is a correlation diagram showing the relationship between the oxygen concentration of the ultra-low overall expansion rate coal and the cost of the ultra-low expansion rate coal measured at a temperature increase rate of 12 ° C / min.
7 is a correlation diagram showing the relationship between the oxygen concentration of the ultra-low overall expansion rate coal and the cost of the ultra-low overall expansion rate measured at a temperature increase rate of 6 ° C / min.

The strengths such as the rotational strength index and the drop strength index of the coke indicate the amount of powder coke generated from the lump coke (or the remaining amount of the lump coke) when a mechanical impact is applied to the lump coke.

The particle size distribution of coke after giving a mechanical impact has a peak of granulation and a peak of fine grain normally. The coke belonging to the peak of this granulation is produced by volume breakdown. In addition, the coke which belongs to a fine particle peak is produced | generated by surface destruction. The boundary between the coarse peak (coke generated by volume breakage) and the fine peak (coke generated by surface breakage) in the particle size distribution is changed by the coke particle size before applying a mechanical impact, so that In the case of coke, it is approximately 6 mm.

Breakage of coke is brittle fracture starting from a defect in the coke. In volume breakdown and surface breakdown, the defects causing the breakdown are different. The starting point of volume destruction is a large crack that can be observed by the naked eye. In addition, the starting point of surface destruction is a part where adhesion of coal particles (average particle size of about 1 mm) is incomplete, and a small crack which can be visually recognized by a microscope.

Large cracks, which are the cause of volume breakdown, are generated by thermal stress caused by uneven shrinkage of the entire coke. The amount of cracking is governed by the temperature distribution in the coke during dry distillation and the shrinkage coefficient during coal stocking. On the other hand, small cracks that cause surface breakage occur not from the shrinkage of the entire coke, but from the stress due to local and nonuniform shrinkage between the coal particles. In addition, the amount of incomplete adhesion of coal particles, which is a major cause of surface breakage, is governed by the cohesiveness and bulk density of coal.

Here, among the powder cokes produced by the coke strength test, powder coke having a particle size of 6 mm or less is classified as coke produced by surface destruction.

The present inventors have found that by measuring the cost V (or the expansion rate b), by raising the temperature raising rate during coal softening, the items can distinguish coals having different total expansion rates of 0% from each other. For example, in patent document 1, since the method prescribed | regulated to JIS M 8801 is used, the temperature increase rate at the time of obtaining the cost-effectiveness at the time of coal softening is 3.0 +/- 0.1 degreeC / min. However, in the present invention, the temperature increase rate is raised to 6.0 ° C / min or more, and the cost V (or the expansion rate b) is measured so that the items can be distinguished from other coals having a total expansion rate of 0%. In addition, in this specification, "coal whose total expansion rate is 0% (extreme low total expansion rate coal)" is defined as coal whose total expansion rate measured in the expansion test of JIS M 8801 is 0%. When the expansion rate b of this ultralow overall expansion rate carbon is measured by ISO 8264, this expansion rate b becomes a predetermined minimum value. In this case, it is not possible to distinguish the expansion rates b of the plurality of extremely low overall expansion factors. In addition, since the cost V and the expansion rate b can be mutually converted by the above formula (2), both of them can be used as expansion characteristics indicating the expansion rate.

The reason is as follows. When the coal is heated, gas is generated inside the molten coal particles, and the molten coal particles are expanded by the pressure of the generated gas. As the temperature increase rate increases, the rate of generation of gas due to pyrolysis increases. By increasing the generation rate of this gas, the coal particles expand even if the heat melt amount of the coal particles is small. Therefore, the cost difference which is not obtained by the temperature increase rate of JIS M 8801 can be measured by raising a temperature increase rate.

In order to investigate the effect of the rate of temperature increase on this cost difference, an expansive test was conducted using a test apparatus used by the dilatometer method of JIS M 8801. In this expansible test, the piston was inserted into a tubular tube containing coal D having a total expansion ratio of 0%, heated at a predetermined temperature raising rate, and the displacement of the piston was measured. 1 shows the relationship between the heating temperature and the displacement amount of the piston. The data of the measurement example 1 has shown the displacement amount of the piston when heated at the temperature increase rate of 3.0 degree-C / min prescribed | regulated to JISM 8801. In addition, the data of the measurement example 2 has shown the displacement amount of the piston at the time of heating at the temperature increase rate of 12.0 degree-C / min faster than the temperature increase rate prescribed | regulated to JIS M 8801.

As shown in FIG. 1, when heated at the temperature increase rate of 3.0 degreeC / min, coal did not expand. On the other hand, when heated at a temperature increase rate of 12.0 ° C / min, coal was expanded and the piston was greatly displaced. Thus, even when coal which does not expand at a temperature increase rate of 3.0 ° C./min is used, a large expansion rate can be reliably obtained by measuring the expansion rate at a temperature increase rate of 12.0 ° C./min.

In addition, the inventors of the present invention have described the cost of coal softening measured by an expansive test in which the temperature rising rate Vtemp at the time of coal softening is 6.0 ° C./min or more, and the measuring method defined in JIS M 8813, for the ultra-low overall expansion rate coal. It was found that there was a constant correlation between the measured oxygen concentrations of coal.

Specifically, it was found that, for the ultra-low overall expansion rate coal, the higher the oxygen concentration of the coal described above, the lower the cost at the time of coal softening described above.

When the oxygen concentration in the coal is large, radicals generated by pyrolysis at the time of coal softening are inactivated by oxygen and easily stabilized. Therefore, it is thought that coking property (softening meltability) falls with the increase of the oxygen concentration in coal. Therefore, the cost at the time of coal softening of the extremely low total expansion rate coal used for a real coal blend can be estimated easily by the following method. First, for the main raw coal for coke production, the cost of coal softening and the oxygen concentration of coal are measured by the above method, and the cost of coal softening (standard cost) and the oxygen concentration of coal (standard oxygen concentration) Create a database that represents the relationship. Contrast this database with the oxygen concentration of the ultra-low overall expansion rate coal.

By this method, it is possible to omit the expansive test of the ultra-low overall expansion rate coal, which requires time for measurement, and to estimate the cost of coal softening of the ultra-low overall expansion rate coal using the oxygen concentration of coal. The oxygen concentration of this coal is analyzed with chemical elements such as carbon for quality control of the raw coal of the coke raw material. The analysis method of the oxygen concentration of this coal is not limited to the measuring method prescribed | regulated by JIS M 8813. For example, the measurement method specified in ISO 333 or ISO 1994 may be used.

In addition, the oxygen concentration of the ultra-low overall expansion rate coal is 9 mass% or more, as shown to FIG. 6 and FIG. 7 mentioned later, for example. That is, the lower limit of the oxygen concentration of coal (extreme low total expansion rate coal) whose total expansion rate is 0% can be prescribed | regulated as 9 mass%.

Here, as mentioned above, coke strength can be estimated by obtaining the void filling degree at the time of coal softening. In addition, the void filling degree Z (-) at the time of coal softening can be computed from following formula (3) using the bulk density Sd (g / cm <3>) of the coal at the time of coke oven charge.

That is, by calculating the cost V (cm 3 / g) at the time of coal softening and the bulk density Sd (g / cm 3) of the coal at the time of charging the coke furnace, the void filling degree Z at the time of coal softening is calculated to estimate the coke strength. can do.

In addition, the cost V at the time of coal softening is computed by Formula (1) and Formula (2) mentioned above using the expansion rate b (%) measured by the expansion system of JISM 8801.

However, when measuring expansion rate b, electric furnace is heated at the temperature increase rate of 6.0 degreeC / min or more faster than the temperature increase rate of the expansion system method of JISM 8801 in the temperature range of 300 degreeC or more and 500 degrees C or less. Preferably, the electric furnace is heated at a temperature increase rate of 12 ° C./min or more. It is preferable that this temperature increase rate is 50 degrees C / min or less in consideration of the measurement accuracy of expansion rate and the heating capability of an electric furnace. In addition, similar to JIS M 8801 (or ISO 8264), the expansion ratio b (%) is defined as "a percentage of the initial length of the sample molded into the rod shape of the displacement from the zero point of the piston to the highest position". . In addition, test conditions other than a temperature increase rate comply with the specification of JISM 8801 (or ISO 8264).

In addition, the relationship between void filling degree Z and coke strength at the time of coal softening derived from said Formula (1)-(3) is calculated | required previously. From this relationship, coke strength can be estimated.

The method of estimating coke strength is explained in full detail. First, the cost-effectiveness at the time of softening various coals (item) is measured, these coals are mix | blended, and it distills and manufactures coke. In that case, about coal (extreme low total expansion rate coal) whose total expansion rate is 0%, the relationship between the oxygen concentration (standard oxygen concentration) of coal and the cost (standard cost) at the time of coal softening is calculated | required. In addition, the bulk density of coal at the time of charging coke oven is measured. Next, the coke strength of the manufactured coke is measured. For example, the drum strength index DI ¹⁵⁰ ₆ by the drum test method of JISK2151 is measured as coke strength. That is, as coke strength DI, the drum strength index DI ^r _d which is a dmm body weight percentage after r rotation can be used. However, as the coke strength, other strength indices such as the micomb strength index of ISO and the tumbler strength index of ASTM may be measured.

In addition, the relationship between the void filling (standard void filling) and the coke strength DI ¹⁵⁰ ₆ (standard coke strength) at the time of coal softening calculated from the cost of coal softening and the bulk density of coal at the time of charging the coke furnace is obtained. In the case of using a coal blend containing two or more kinds of coals, the cost of the coal softening (the cost of the coal blend, the average cost of the coal blend), and the cost of the coal (actual value or estimated value) We can use the weighted average of (weighted average cost).

As described above, in order to estimate the coke strength, the cost of the softening of the coal used is measured by the above method, and the bulk density of the coal (blended coal) at the time of charging the coke furnace at the time of distillation is determined by the coal moisture or particle size. We predict from the back. Moreover, the void filling degree at the time of coal softening is computed from the value of the cost at the time of the softening of coal (combined coal) and the bulk density of the coal (at the time of coke oven charging). Coke strength is estimated from the value of this void filling degree using the relationship of the void filling degree (standard pore filling degree) and coke strength (standard coke intensity) calculated | required before coal softening.

In addition, when the cost of the ultra-low overall expansion rate coal is not measured directly, the extremely low total used for the database which shows the relationship between the oxygen concentration (standard oxygen concentration) of the coal prepared previously and the cost (standard cost) at the time of coal softening Contrast the oxygen concentration of the expansion rate coal. This method estimates the cost (estimated cost) of coal softening of the extremely low overall expansion rate coal. If the cost of the very low overall expansion rate coal is not measured directly, this estimated cost is used to calculate the weighted average cost. In addition, about coal other than the ultra-low overall expansion rate coal which comprises a coal blend, coal softening from the expansion rate measured by the said expansion test or JIS M 8801 expansion system method whose temperature rising rate Vtemp at the time of coal softening is 6.0 degree-C / min or more. Calculate the cost of the city. The weighted cost multiplied by the blending ratio of coal is added to this cost value for each coal other than the extremely low overall expansion rate coal to obtain the sum of the weighted cost costs. In addition, the weight estimation cost cost obtained by multiplying the compounding ratio of coal by the estimated cost value described above is added to the ultra-low overall expansion rate coal to obtain the sum of the weight estimation cost costs. The weighted average cost (average cost of the combined coal) can be calculated by adding the sum of the weighted estimated costs and the sum of the weighted costs. In addition, the bulk density of coal (blended coal) at the time of charging the coke oven at the time of distillation is estimated from coal moisture, particle size, etc. In addition, the void filling degree at the time of coal softening is calculated from the value of the cost at the time of the softening of coal (mixed coal) and the bulk density of the coal (mixed coal) at the time of coke oven charge. Coke strength is estimated from the value of this void filling degree using the relationship of the void filling degree (standard pore filling degree) and coke strength (standard coke intensity) calculated | required before coal softening.

In addition, coke is a porous material, and coke strength is influenced by porosity. In other words, when the porosity of the coke is high, the effective cross-sectional area decreases, and the physical properties such as the effective elastic modulus and the effective surface energy change, so that the coke strength decreases. Therefore, if the relationship between the porosity of coke and coke strength is calculated | required, and the influence of the change of the porosity by coal mix, the bulk density of coal, etc. on coke strength is considered, the estimation accuracy of coke strength will further improve.

Here, the porosity of coke can be estimated from the bulk density and coke yield of coal, for example. In addition, a coke yield can be estimated from the volatile matter of coal, for example.

As described above, in the present invention, coal is placed in the tubule of the expansion system, a piston is inserted into the tubule, and the coal put in the tubule is heated so that the temperature increase rate at the time of coal softening becomes 6 ° C / min or more, The displacement amount of the piston is measured, and the expansion rate (or cost) is calculated from this displacement amount. In this case, 300 degreeC or more and 500 degrees C or less may be sufficient as the temperature range which makes a temperature increase rate 6 degreeC / min or more. In addition, conditions other than a temperature increase rate may be according to the expansion test method of JISM 8801. Similarly, conditions other than a temperature increase rate may be according to the expansible test method of ISO 8264. The coal for measuring the expansion ratio may be coal having a total expansion ratio of 0% measured by the expansion test method of JIS M 8801. In addition, the coal measuring the expansion rate may be a single item of coal or a coal blend containing a plurality of items of coal. In addition, the expansion rate is calculated as a percentage of the initial length of coal in the tubing, of the displacement from the zero point of the piston to the highest position (the position of the piston when the coal is inflated).

About the ultra-low overall expansion rate coal, the cost at the time of coal softening can be estimated by the following method. That is, the cost-effectiveness (standard cost) at the time of softening of ultra-low overall expansion rate coal calculated | required from the expansion rate of coal (extreme low overall expansion rate coal) measured by the above-mentioned expansion test whose temperature rising rate Vtemp at the time of coal softening is 6.0 degrees C / min or more. And the relationship between the oxygen concentration (standard oxygen concentration) of the ultra-low overall expansion rate coal. On the basis of this relationship, the cost of the coal softening of the ultra low overall expansion coal is estimated from the oxygen concentration of the ultra low overall expansion coefficient coal.

Moreover, in 1st Embodiment of the measuring method of the gap filling degree of this invention, some coal is prepared, and the coalescing method of the above-mentioned coal is measured about at least 1 coal among these coals, Find the cost of coal softening. In addition, the coal measuring an expansion rate may contain at least the ultra-low overall expansion rate coal whose total expansion rate measured by the expansion test method of JISM 8801 is 0%. That is, when the ultra low expansion rate coal is included in the plurality of coals, the expansion rate of the ultra low expansion rate coal is measured by applying the above-described method of measuring the expansion rate of coal to at least one ultra low expansion rate coal, and the equation (2) is used for the ultra low expansion rate coal. Obtain the cost of softening the expansion rate coal. Moreover, the average cost of coal blended coal is calculated | required by weighting-averaging the cost at the time of softening of some coal, using the compounding ratio of some coal as weight. Then, as shown by Formula (3), this average cost is multiplied by the bulk density of the coal briquettes at the time of coke oven charging, and the void filling degree at the time of softening of the coal briquettes is calculated | required. Here, the coal for measuring the void filling degree may be a single item of coal or a mixed coal in which coals of a plurality of items are blended. In addition, when obtaining the void filling degree at the time of coal softening of individual coal, the expansion rate of coal is measured using the above-mentioned measuring method of the expansion rate of coal, and the cost-value at the time of softening of coal is calculated | required from this expansion rate. As shown in equation (3), the cost density at the time of coal softening is obtained by multiplying this cost by the bulk density at the time of charging the coke with coal.

Moreover, in 2nd Embodiment of the measuring method of the void filling degree of this invention, the some coal containing the ultra low total expansion rate coal whose total expansion rate measured by the expansion test method of coal of JISM 8801 is 0%, is prepared, Among these coals, the cost estimate at the time of softening of some coal is calculated | required by applying the above-mentioned cost estimation method of coal about the ultra-low overall expansion rate coal. Moreover, the average cost of coal blended coal is calculated | required by weighting-averaging the cost at the time of softening of some coal, using the compounding ratio of some coal as weight. Then, as shown by Formula (3), this average cost is multiplied by the bulk density of the coal briquettes at the time of coke oven charging, and the void filling degree at the time of softening of the coal briquettes is calculated | required. In addition, when obtaining the void filling degree at the time of coal softening of single coal, the ultra-low total expansion rate coal whose total expansion rate measured by the expansion test method of JIS M 8801 is 0% using the above-mentioned cost estimation method of coal. Find the cost of softening. As shown in equation (3), this cost is multiplied by the bulk density at the time of charging the coke oven of the ultra-low overall expansion rate coal, and the void filling degree at the time of softening the ultra-low overall expansion rate coal is obtained.

In the first embodiment of the coal blending method of the present invention, a plurality of coals are prepared, and among the plurality of coals, a method of measuring the expansion ratio of coal described above is applied to at least one coal, Find the cost of softening. In addition, the coal measuring an expansion rate may contain at least the ultra-low overall expansion rate coal whose total expansion rate measured by the expansion test method of JISM 8801 is 0%. That is, when the ultra low expansion rate coal is included in the plurality of coals, the expansion rate of the ultra low expansion rate coal is measured by applying the above-described method of measuring the expansion rate of coal to at least one ultra low expansion rate coal, and the equation (2) is used for the ultra low expansion rate coal. Obtain the cost of softening the expansion rate coal. Moreover, the average cost of coal blended coal is calculated | required by weighting-averaging the cost at the time of softening of some coal, using the compounding ratio of some coal as weight. Then, as shown by Formula (3), this average cost is multiplied by the bulk density of the coal briquettes at the time of coke oven charging, and the void filling degree at the time of softening of the coal briquettes is calculated | required. The coke strength of coke using a coal blend is estimated from the pore filling at the time of softening of the coal briquettes based on the relationship between the measured pore filling (standard pore filling) and the previously measured coke strength (standard coke strength). . Based on this estimation, some coal is mix | blended so that the coke strength of the coke using the coal briquettes may become more than predetermined value (target value). As the coke strength, the drum strength index DI ¹⁵⁰ ₆ by drum test method of JIS K 2151 - may be used (). This drum strength index DI ¹⁵⁰ ₆ represents the ratio of the 6 mm body shape after 150 revolutions by a drum testing machine. As the coke strength, other strength indices such as the microcomputer strength index of ISO and the tumbler strength index of ASTM may be used. In addition, the coal blend may contain at least coal whose total expansion ratio measured by the expansion test method of JIS M 8801 is 0%. In addition, about the extremely low total expansion rate coal in a some coal, the above-mentioned measuring method of the expansion rate of coal (method of measuring expansion rate at the temperature increase rate of 6.0 degree-C / min or more), or the above-mentioned cost estimation method of coal (cost from oxygen concentration is cost The method of estimating the enemy is used to determine the expansion rate (cost) of the ultra-low overall expansion rate coal.

Moreover, in 2nd Embodiment of the coal mixing | blending method of this invention, the some coal containing the ultra low total expansion rate coal whose total expansion rate measured by the expansion test method of coal of JISM 8801 is 0% is prepared, and this plurality Among the coals, the cost cost of softening a plurality of coals is obtained by applying the above-described cost estimation method of coal to the extremely low overall expansion rate coal. Moreover, the average cost of coal blended coal is calculated | required by weighting-averaging the cost at the time of softening of some coal, using the compounding ratio of some coal as weight. Then, as shown by Formula (3), this average cost is multiplied by the bulk density of the coal briquettes at the time of coke oven charging, and the void filling degree at the time of softening of the coal briquettes is calculated | required. The coke strength of coke using a coal blend is estimated from the pore filling at the time of softening of the coal briquettes based on the relationship between the measured pore filling (standard pore filling) and the previously measured coke strength (standard coke strength). . Based on this estimation, some coal is mix | blended so that the coke strength of the coke using the coal briquettes may become more than predetermined value (target value). As the coke strength, the drum strength index DI ¹⁵⁰ ₆ by drum test method in JIS K2151 - may be used (). This drum strength index DI ¹⁵⁰ ₆ represents the ratio of the 6 mm body shape after 150 revolutions by a drum testing machine. As the coke strength, other strength indices such as the microcomputer strength index of ISO and the tumbler strength index of ASTM may be used. In addition, the coal blend may contain at least coal whose total expansion ratio measured by the expansion test method of JIS M 8801 is 0%.

Example

(First Embodiment and Second Embodiment)

For each of the coals A to G, an expansion test was performed by the expansion system method of JIS M 8801. However, the temperature increase rate in 300 degreeC or more and 500 degrees C or less which is the softening melting temperature of coal was set to 12 degreeC / min faster than JIS. These coals A to G were grained at a particle size of 2.8 mm or less (body weight 2.8 mm). As shown in Table 4, the costs of coal A, coal B, coal C, coal D, coal E, coal F and coal G are 5.07 cm 3 / g, 2.10 cm 3 / g, 1.75 cm 3 / g and 1.65 cm 3 /, respectively. g, 1.43 cm 3 / g, 1.29 cm 3 / g and 1.27 cm 3 / g.

As shown in Table 1, when the temperature increase rate was 3.0 ° C / min, the cost-effectiveness of the ultra-low overall expansion rate coals C to G could not be distinguished. However, as shown in Table 4, the cost of these coals C-G was distinguishable by raising a temperature increase rate to 12.0 degreeC / min. Moreover, about the coals A and B whose total expansion rate is not 0%, the cost difference of coal A and coal B expanded by raising the temperature increase rate from 3.0 degreeC / min to 12.0 degreeC / min.

The oxygen concentration of coal C to G, which is an extremely low overall expansion coefficient coal, was measured, and the relationship between the oxygen concentration (O%) of coal and the cost V at the time of coal softening was determined. The oxygen concentration (O%) of the above-mentioned coal was measured based on "the oxygen percentage calculation method (measurement method of oxygen content rate)" of the coals and coke-element analysis method of JIS M 8813. It is a figure which shows the relationship between the oxygen concentration (O%) of coal C-G which is extremely low total expansion rate coal, and the cost V at the time of coal softening. As shown in FIG. 6, the oxygen concentration (O%) of coal was low, and the cost V at the time of coal softening increased. As an example of the equation showing this relationship, the cost V at the time of coal softening is represented by the following formula (4) using the oxygen concentration (O%) of the coal.

By measuring the oxygen concentration (O%) of the ultra-low overall expansion rate coal and substituting this oxygen concentration (O%) in equation (4), the cost V at the time of coal softening can be estimated easily. In addition, as a formula which shows the relationship between the oxygen concentration (O%) of coal and the cost V at the time of coal softening, since a cost can be estimated easily, it is preferable to use the linear formula (4). However, any estimation equation can also be used as a relationship between the oxygen concentration (O%) of coal and the cost V at the time of coal softening.

In FIG. 6 mentioned above, the oxygen concentration of coal G with the highest oxygen concentration was 12%. When measuring the expansion rate (cost-effectiveness) of the ultra-low overall expansion rate coal whose oxygen concentration is higher than this coal G, it is preferable to set a heating rate higher than 12 degree-C / min. By this method, the cost at the time of coal softening can be distinguished, and the relationship between the oxygen concentration of coal and the cost at the time of coal softening can be calculated | required primarily. In other words, the cost of the coal softening can be distinguished by setting the temperature raising rate to 12 ° C / min for the ultra-low overall expansion rate coal having an oxygen concentration of 12% or less. In addition, for extremely low total expansion coefficient coal whose oxygen concentration is higher than 12%, the cost at the time of coal softening can be reliably distinguished by setting a temperature increase rate at a speed | rate faster than 12 degree-C / min.

Further, by calculating costs less and subjected to a breaking strength test for the formulation Tan X ₁ to X _10, including the coal C to G. Table 5 shows the results of the mixed coals X ₁ to X ₅ (Example 1), and Table 6 shows the results (the second example) of the mixed coals X ₆ to X ₁₀ .

Here, a description will be given of a specific calculation of the cost method enemy during softening of the blended coal burnt X _1. Coal other than the ultra-low overall expansion rate coal contained in the blended coal X ₁ (coal whose total expansion rate is not 0%), that is, the cost cost at the time of coal softening of coals A and B is determined in the expansion test by the expansion system method of JIS M 8801. Is measured by. The weighted cost of 0.6325 (cm 3 / g) is calculated by multiplying the cost of 2.53 (cm 3 / g) of coal A shown in Table 1 by the mixing ratio of coal A 0.25. The weighted cost 0.2625 (cm 3 / g) is calculated by multiplying the cost ratio 1.05 (cm 3 / g) of coal B shown in Table 1 by 0.25 in the mixing ratio of coal B 0.25. By measuring the oxygen concentration of coal C and interpolating or extrapolating the measured oxygen concentration in FIG. 6, an estimated cost of 1.75 (cm 3 / g) at the time of coal softening of coal C is obtained. The estimated cost value at the time of coal softening of this coal C is multiplied by the blending ratio of coal C 0.50 to calculate the weighted estimated cost 0.875 (cm 3 / g). By adding the weighted cost estimates of the coals A and B and the estimated weighted costs of the coal C, the cost 1.77 (cm 3 / g) at the time of coal softening of the coal blend X ₁ is obtained. Even for blended Tan X ₂ to X _10, in a manner similar to calculate the cost at the time of small coal softening. In addition, the cost (expansion rate) of the ultra-low overall expansion rate coal may be measured directly at the temperature increase rate of 12 degree-C / min, and the cost value of a coal blend may be calculated | required. In this case, the weighted cost 0.875 (cm 3 / g) is calculated by multiplying the cost 1.75 (cm 3 / g) at the time of coal softening of the coal C by 0.50 of the mixing ratio of the coal C. Thereafter, the total cost-weight of the coals A to C can be summed to obtain a cost-effective 1.77 (cm 3 / g) at the time of coal softening of the coal blend X ₁ .

In addition, the relationship between the void filling degree and coke strength DI shown in Table 5 and Table 6 is shown in FIG. The black square data is the first example using the coal briquettes X ₁ to X ₅ corresponding to Table 5. Data of the white triangle is a second example using the formulation Tan X ₆ to X _10, which corresponds to Table 6. 2 is a pore filling degree in coal softening, and a vertical axis is coke strength DI. Coke strength DI, is the drum strength index DI ¹⁵⁰ ₆ by drum test method in JIS K 2151. As shown in FIG. 2, the void filling degree and the coke strength DI have a constant correlation. Therefore, by accumulating this correlation as a database, the intensity | strength of the coke which contains the weak coal whose total expansion rate is 0% in a coal blend can be estimated correctly.

(3rd Example and 4th Example)

For each of the coals C to G, an expansion test was performed by the expansion system method of JIS M 8801. However, the temperature increase rate in 300 degreeC or more and 500 degrees C or less which is the softening melting temperature of coal was set to 6 degreeC / min faster than JIS. These coals C to G were sized to a particle size of 2.8 mm or less (body weight 2.8 mm). As shown in Table 7, the costs of coal C, coal D, coal E, coal F and coal G are 1.43 cm 3 / g, 1.34 cm 3 / g, 1.26 cm 3 / g, 1.25 cm 3 / g and 1.24 cm 3 / g, respectively. It was.

As shown in Table 1, when the temperature increase rate was 3.0 ° C / min, the cost of coal C to G in which the total expansion ratio was 0% could not be distinguished. However, as shown in Table 7, the cost of these coals C-G was distinguishable by raising a temperature increase rate to 6.0 degree-C / min. In addition, from the comparison of Tables 4 and 7, it was found that by increasing the temperature increase rate, the cost difference between the coals C to G increases, and the cost of coals C to G can be distinguished more remarkably.

The oxygen concentration of coals C to G, which is coal (extreme low overall expansion rate coal) having a total expansion rate of 0%, was measured, and the relationship between the oxygen concentration (O%) of coal and the cost V at the time of coal softening was determined. The oxygen concentration (O%) of coal was measured based on the "oxygen percentage calculation method (measurement method of oxygen content rate)" of the coals and coke-element analysis method of JIS M 8813. It is a figure which shows the relationship between the oxygen concentration (O%) of coal C-G, and the cost V at the time of coal softening. As shown in FIG. 7, the oxygen concentration (O%) of coal became low, and the cost V at the time of coal softening increased. As an example of an equation showing this relationship, the cost V at the time of coal softening is represented by the following formula (5) using the concentration of O% of coal.

As shown in FIG. 6 and FIG. 7, even if coal (extreme low total expansion rate coal) whose total expansion rate measured in the conventional expansion test of JIS M 8801 is 0%, the temperature increase rate in an expansion test is 6.0 degree-C / min. By raising the above, it turns out that the cost at the time of coal softening can be distinguished, and the relationship between the cost at the time of coal softening and the oxygen concentration of coal can be approximated first.

Further, by calculating costs less and subjected to a breaking strength test for the formulation Tan X ₁ to X _10, including the coal C to G. The test results (third example) of the mixed coals X ₁ to X ₅ are shown in Table 8, and the test results (fourth example) of the mixed coals X ₆ to X ₁₀ are shown in Table 9.

Here, a description will be given of a specific calculation of the cost method enemy during softening of the blended coal burnt X _1. Ultra low thermal expansion coefficient when the total cost of the softening of the coal non-burnt coal A and B included in the formulation Tan X ₁ little was measured using an inflatable test according to the JIS M 8801 gyebeop expansion. The weighted cost 0.6325 (cm <3> / g) was computed by multiplying the compounding ratio of coal A 0.25 by the cost 2.53 (cm <3> / g) at the time of coal softening of coal A shown in Table 1. Moreover, the weighted cost 0.2625 (cm <3> / g) was computed by multiplying the compounding ratio of coal B 0.25 by the cost 1.05 (cm <3> / g) at the time of coal softening of the coal B shown in Table 1. By measuring the oxygen concentration of coal C and interpolating or extrapolating the measured oxygen concentration in FIG. 7, an estimated cost of 1.43 (cm 3 / g) at the time of coal softening of coal C was obtained. The estimated cost value at the time of coal softening of this coal C was multiplied by the blending ratio of coal C 0.50 to calculate the weighted estimated cost 0.715 (cm 3 / g). By adding together the weighted cost estimates of the coals A and B and the weighted cost estimates of the coal C, the cost 1.61 (cm 3 / g) at the time of coal softening of the coal blend X ₁ was obtained. Even for blended Tan X ₂ to X _10, it was calculated by methods less cost at the time of coal softening the same. In addition, the cost (expansion rate) of the ultra-low overall expansion rate coal may be measured directly at the temperature increase rate of 6 degrees C / min, and the cost value of a coal blend may be calculated | required. In this case, the weighted cost 0.715 (cm 3 / g) is calculated by multiplying the cost 1.43 (cm 3 / g) at the time of coal softening of the coal C by 0.50 of the mixing ratio of the coal C. Thereafter, the weighted cost of coals A to C can be summed to obtain a cost of 1.61 (cm 3 / g) at the time of coal softening of the coal blend X ₁ .

Moreover, the relationship between the void filling degree and coke intensity DI shown in Table 8 and Table 9 is shown in FIG. The black square data is a third example using the coal briquettes X ₁ to X ₅ corresponding to Table 8. The data of the white triangles is a fourth example using the coal briquettes X ₆ to X ₁₀ corresponding to Table 9. 3 is a pore filling degree in coal softening, and a vertical axis is coke strength DI. Coke strength DI, is the drum strength index DI ¹⁵⁰ ₆ by drum test method in JIS K 2151. As shown in FIG. 3, the void filling degree and the coke strength DI have a constant correlation. By accumulating this correlation as a database, the strength of the coke can be easily estimated even when a weak coal having a total expansion rate of 0% is used as the coal briquettes of the coke. In addition, from the comparison of FIG. 2 and FIG. 3, it was found that by increasing the temperature increase rate, the difference in the pore filling degree of the coal briquettes X ₁ to X ₁₀ can be enlarged, and the coke strength can be estimated more accurately.

In the first to fourth embodiments described above, the expansion test of coal (coal A, coal B) other than the extremely low total expansion coefficient coal was performed by the expansion system method of JIS M 8801. Also in the expansion test of coal other than the ultra-low overall expansion rate coal, the temperature increase rate at the time of coal softening can be raised to 6.0 degree-C / min or more similarly to ultra-low overall expansion rate coal. For example, in the 5th and 6th Example shown below, the temperature increase rate at the time of coal softening with respect to coal A and B is set to 12.0 degreeC / min.

(5th and 6th embodiment)

Further, using the costly and oxygen concentration of the coal C to G of the coal A and B shown in Table 4, the strength was estimated DI (estimated DI) of the coke produced from the compounded carbon X ₁₁ to X _20. The specific cost of the blended coals X ₁₁ to X ₂₀ was determined by a weighted average method as described later. In addition, the void filling degree was computed using Formula (3), and the coke strength (measured DI) was measured by the breaking strength test. Table 10 (Example 5) shows the cost (weighted average cost) and coke strength DI (estimated value and measured value) of the coal briquettes using the coal briquettes X ₁₁ to X ₁₅ . Similarly, Table 11 (Example 6) shows the cost (weighted average cost) and coke strength DI (estimated value and measured value) of the coal briquettes using the coal briquettes X ₁₆ to X ₂₀ .

The specific calculation method of the weighted average cost-effectiveness of blended coal X ₁₁ is demonstrated. The weighted cost 1.521 (cm 3 / g) is calculated by multiplying the cost ratio 5.07 (cm 3 / g) at the time of coal softening of coal A shown in Table 4 by the mixing ratio of coal A 0.3. The weighted cost 0.63 (cm <3> / g) is computed by multiplying the cost ratio 2.10 (cm <3> / g) at the time of coal softening of coal B shown in Table 4 by the compounding ratio of coal B 0.3. By measuring the oxygen concentration of coal C and interpolating or extrapolating the measured oxygen concentration in FIG. 6, an estimated cost 1.75 (cm 3 / g) at the time of coal softening of coal C is obtained. The estimated cost value at the time of coal softening of this coal C is multiplied by the compounding ratio of coal C 0.40 to calculate the weighted estimated cost 0.7 (cm 3 / g). Next, the weighted average cost of 2.85 (cm 3 / g) of the coal blend X ₁₁ is calculated by summing the weighted cost of coal A and B and the weight estimated cost of coal C. Even for blended carbon X ₁₂ to X _15, and calculates the weighted average cost less in a similar way.

Similarly, with reference to Table 4 and FIG. 6, the weighted average specific cost of coal blend X ₁₆ to X ₂₀ was obtained. In addition, the gap filling at the time of coal softening was computed using Formula (3). Table 11 shows the calculated weighted average cost and porosity filling during coal softening.

It is also possible to directly calculate the cost of the ultra-low overall expansion rate coal and calculate the cost of the blended coal. For example, the composition of each formulation in the coal burnt X ₁₁ is, coal A, 30% by mass, respectively the blending ratio of coal and coal B C, 30% by mass, 40% by weight. The cost of this blended coal X ₁₁ can be calculated by adding up the product of the cost of each coal and the blending ratio of each coal. For example, as shown in Table 4, since the cost of coal A is 5.07, the cost of coal B is 2.10 and the cost of coal C is 1.75, the cost of this blended coal X ₁₁ is calculated from Equation 6 to 2.85. do.

5 shows the relationship between the void filling and the coke strength DI. The black square data (measured DI) corresponds to the coal briquettes X ₁₁ to X ₁₅ shown in Table 10 as the fifth embodiment. The white triangle data (measured DI) corresponds to Table 11 as the sixth embodiment. Also using the solid line of Figure 5, from Figure pore filling during coal softening can be obtained to estimate DI of coke incorporated with carbon X ₁₁ to X _20. For example, since the pore filling degree of blended coal X ₁₁ is 2.28 (−), the estimated DI of blended coal X ₁₁ can be evaluated as 79.7 (−) from the solid line of FIG. 5. From Table 10 and Table 11, it can be seen that the difference between the estimated DI of the coke using the coal blend X ₁₁ to X ₂₀ and the performance DI are small. Thus, by performing an expansion test at the temperature increase rate of 6 degrees C / min or more, coke strength can be estimated correctly and easily even if the coal blend contains 0% of the total expansion rate. In addition, the cost-effectiveness of the target coal blend can be determined so that coke strength becomes about predetermined value or more. Therefore, the compounding ratio of the coal item used for a coal blend and each coal item can be determined. For example, in order to make coke strength DI 78 (-) or more, a coal briquette having a weighted average specific cost of 2.81 (cm 3 / g) or more (for example, a coal briquette having a weighted average specific cost of 2.85 (cm 3 / g)) X ₁₁ ]. Thus, even when the coal used (coal in a coal blend) is changed, the compounding ratio of each coal can be easily determined.

(Variation)

In the above-described embodiment, the coal briquettes containing coal having an overall expansion rate of 0%, coal having an overall expansion rate of 0%, and coke using this coal mixture have been described. However, the measuring method of the expansion rate of coal of the present invention, the measuring method of void filling degree, and the coal mixing method are not limited to these embodiment. That is, this invention is applicable also to the coal blend which consists only of coal whose total expansion rate is more than 0%, the coal whose total expansion rate is more than 0%, and the coke using this mixture coal.

In addition, the expansion ratio b (%) and estimated cost V measured by the dilatometer may be used for estimating coke strength, as well as for estimating other physical quantities such as, for example, expansion pressure.

The method of measuring the expansion rate, the method of estimating the cost of coal, the method of measuring the void filling degree, and the coal blending method applicable to coal having a total expansion rate of 0% can be provided.

Claims (20)

Put coal in customs,
Insert a piston into this tubule,
The coal is heated so that the temperature increase rate at the time of softening of the coal becomes 6 ° C / min or more,
Measure the displacement of the piston,
The expansion rate of said coal is calculated | required from this displacement amount, The measuring method of the expansion rate of coal. The method other than the said temperature increase rate is based on the expansion test method of JIS M 8801, The measuring method of coal's expansion rate of Claim 1 characterized by the above-mentioned. The method other than the said temperature increase rate is based on the expansion test method of ISO 8264, The measuring method of coal's expansion rate of Claim 1 characterized by the above-mentioned. The method for measuring the expansion rate of coal according to claim 1, wherein the coal is an extremely low total expansion rate coal having a total expansion rate of 0% as measured by the expansion test method of JIS M 8801. It is a cost estimation method at the time of coal softening which estimates the cost at the time of coal softening of the ultra-low overall expansion rate coal whose total expansion rate measured by JIS M 8801 coal expansion test method is 0%,
The relationship between the standard cost-effectiveness at the time of softening of the said ultra-low overall expansion rate coal calculated | required from the expansion rate of the said ultra low total expansion rate coal measured by the measuring method of the expansion rate of coal of Claim 1, and the relationship of the standard oxygen concentration of the said ultra low overall expansion rate coal in advance Finding,
A cost estimation method for coal softening, characterized in that the cost of coal softening of the ultra low overall expansion carbon is estimated from the oxygen concentration of the ultra low overall expansion coefficient carbon measured on the basis of this relationship. The said oxygen concentration of the said extremely low total expansion rate coal is 9 mass% or more, The cost estimation method at the time of coal softening of Claim 5 characterized by the above-mentioned. The said oxygen concentration of the said ultra-low overall expansion rate coal is 12 mass% or less, The cost estimation method at the time of coal softening of Claim 5 characterized by the above-mentioned. The expansion rate of the said coal is measured using the measuring method of the expansion rate of the coal of Claim 1,
From this expansion rate, the cost at the time of softening of the coal is obtained,
A method for measuring void filling, wherein the void density at the time of softening of the coal is obtained by multiplying this cost by the bulk density at the time of charging with the coke of the coal. The method for measuring void filling according to claim 8, wherein the coal is an extremely low total expansion coefficient coal having a total expansion ratio of 0% as measured by the expansion test method of JIS M 8801. Preparing a plurality of coals,
Applying the measuring method of the expansion rate of the coal of Claim 1 with respect to at least 1 coal among each coal, the cost-effectiveness at the time of softening of each said coal is calculated | required,
The weighted average of the said cost at the time of softening of each said coal is calculated | required by making the compounding rate of said each coal into a weight, and the average cost-effectiveness of the coal blended is calculated | required,
The average filling ratio is multiplied by the bulk density of the blended coal at the time of charging the coke oven, and the void filling at the time of softening of the blended coal is obtained. The method for measuring void filling according to claim 10, wherein the blended coal contains ultra-low overall expansion coefficient carbon having a total expansion ratio of 0% as measured by the expansion test method of JIS M 8801. Using the cost estimating method of coal according to claim 5, the cost of the softening of the ultra-low overall expansion rate coal having a total expansion rate of 0% measured by the expansion test method of JIS M 8801 is obtained.
A method for measuring void filling, wherein said void density is multiplied by the bulk density at the time of charging the coke oven of said extremely low overall expansion rate coal, and the softness of the said extremely low overall expansion rate coal is calculated | required. A plurality of coals including ultra-low overall expansion rate coal having an overall expansion rate of 0% as measured by the coal expansion test method of JIS M 8801 are prepared,
Among the coals, the cost estimate at the time of softening of each coal is obtained by applying the cost estimation method of coal according to claim 5 to the ultra-low overall expansion rate coal.
The weighted average of the said cost at the time of softening of each said coal is calculated | required by making the compounding rate of said each coal into a weight, and the average cost-effectiveness of the coal blended is calculated | required,
The average filling ratio is multiplied by the bulk density of the blended coal at the time of charging the coke oven, and the void filling at the time of softening of the blended coal is obtained. The oxygen concentration of the ultra-low overall expansion coefficient carbon is 9 mass% or more, The measuring method of the void filling degree of Claim 12 or 13 characterized by the above-mentioned. The oxygen concentration of the ultra-low overall expansion coefficient carbon is 12 mass% or less, The measuring method of the void filling degree of Claim 12 or 13 characterized by the above-mentioned. Preparing a plurality of coals,
Applying the measuring method of the expansion rate of the coal of Claim 1 with respect to at least 1 coal among each coal, the cost-effectiveness at the time of softening of each said coal is calculated | required,
The weighted average of the said cost at the time of softening of each said coal is calculated | required by making the compounding rate of said each coal into a weight, and the average cost-effectiveness of the coal blended is calculated | required,
By multiplying the average cost by the bulk density of the coal briquettes at the time of charging the coke oven, to obtain the void filling degree at the time of softening of the coal briquettes,
Based on the relationship between the standard pore filling at the time of softening of the said coal briquettes and the standard coke strength of the coke manufactured with the said coal briquettes, the coke of the coke using the said coal briquettes from the said pore filling at the time of softening of the said coal briquettes. Estimate the intensity,
A coal blending method, characterized in that each coal is blended so that the coke strength of the coke using the blended coal becomes a predetermined value or more. The coal blending method according to claim 16, wherein the blended coal contains ultra-low overall expansion coefficient coal having a total expansion ratio of 0% as measured by the expansion test method of JIS M 8801. A plurality of coals including ultra-low overall expansion rate coal having an overall expansion rate of 0% as measured by the coal expansion test method of JIS M 8801 are prepared,
Among the coals, the cost estimate at the time of softening of each coal is obtained by applying the cost estimation method of coal according to claim 5 to the ultra-low overall expansion rate coal.
The weighted average of the said cost at the time of softening of each said coal is calculated | required by making the compounding rate of said each coal into a weight, and the average cost-effectiveness of the coal blended is calculated | required,
By multiplying the average cost by the bulk density of the coal briquettes at the time of charging the coke oven, to obtain the void filling degree at the time of softening of the coal briquettes,
Based on the relationship between the standard pore filling at the time of softening of the said coal briquettes and the standard coke strength of the coke manufactured with the said coal briquettes, the coke of the coke using the said coal briquettes from the said pore filling at the time of softening of the said coal briquettes. Estimate the intensity,
A coal blending method, characterized in that each coal is blended so that the coke strength of the coke using the blended coal becomes a predetermined value or more. The coal blending method according to claim 18, wherein an oxygen concentration of the extremely low overall expansion coefficient coal is 9% by mass or more. The coal blending method according to claim 18, wherein an oxygen concentration of the extremely low overall expansion coefficient coal is 12% by mass or less.

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