JP2007246674A - Method for producing coke, and method for producing pig iron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing coke by which strength of the obtained coke is improved, or a method by which humidity conditioning step can be simplified without substantially reducing strength of the obtained coke, and a method for producing pig iron by utilizing coke obtained by the production method. <P>SOLUTION: This method for producing coke comprises charging coal to a carbonization chamber of a coke oven and dry distilling it, which uses coal substantially free of ash, as coal to be charged, being added in an amount of 1 pt.mass or below to 100 pts.mass of raw material coal. This method for producing pig iron uses coke obtained by the method. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a coke production technique and a pig iron production technique using the technique, and more specifically, a coke production technique with improved strength, or the strength of the obtained coke is substantially reduced. The present invention relates to a coke manufacturing technique that can simplify the humidity control process without reducing the temperature, and a pig iron manufacturing technique using the same.

  In the production of coke, in order to increase the strength of the obtained coke, it is known to increase the packing density of the charged coal charged into the carbonization chamber. In order to increase the charging density of the charged coal, the coking coal is conditioned to reduce the moisture content, or it is mechanically compressed when the charged coal is charged into the carbonization chamber. It has been broken. However, at the coke production site, coking coal is usually conveyed by a belt conveyor. However, if the moisture content of the coking coal is reduced to less than about 7%, the coal fine powder is likely to be scattered. Not preferable. On the other hand, the operation of mechanically pressing the charged coal into the carbonization chamber is also complicated.

  For example, Patent Document 1 discloses that dry coal is treated with coarse coal and fine coal for the purpose of providing a pretreatment method for coke oven charging coal that can reliably and stably improve the strength of coke. After adding heavy oil 5-40% and water to finely pulverized coal to form a water slurry, it is granulated into granulated coal having a particle size exceeding the separation point by wet granulation, and then dehydrated A pretreatment method for coal charged in a coke oven is disclosed in which the mixture is mixed with coarse coal. In addition, Patent Document 2 discloses that coke oven charging coal such as strong caking coal, caking coal, non-minor caking coal or the like is used to obtain a high bulk density when producing metallurgical coke. A method for adjusting to a distribution state is disclosed.

Furthermore, Patent Document 3 aims to provide a method for producing high-strength coke by an inexpensive method in order to reduce the production cost of blast furnace coke, and is 50 ° C. lower than the softening start temperature of raw coal. A coke production method is disclosed in which a heavy tar fraction containing 80 wt% or more of a component having a boiling point above temperature is added to the raw coal and dry-distilled to produce high-strength coke. Patent Document 4 discloses a coke production method for producing coke by pulverizing and mixing mixed coal in a coke oven to produce coke as a method for producing coke that improves both strength and productivity. There is disclosed a method for producing coke, characterized in that coke is produced by making the particle size of the coke finer and blending a surfactant with blended coal.
JP 9-31469 A JP 2003-226879 A Japanese Patent No. 3568634 Japanese Patent Laid-Open No. 3-7796

  As described above, the method of reducing the moisture content of the raw coal used to increase the packing density into the carbonization chamber facilitates the scattering of coal fines, so that the moisture content can be reduced to less than about 7%. There is a restriction that it is difficult. On the other hand, the operation of mechanically pressing the charged coal into the carbonization chamber is also complicated.

  The present invention has been made in view of the above circumstances, and a coke production method for improving the strength of the obtained coke, or the humidity conditioning process is simplified without substantially reducing the strength of the obtained coke. It is an object of the present invention to provide a method that can be used, and a method for producing pig iron that uses coke obtained by the production method.

  The coke production method of the present invention that has been able to solve the above problems is a method for producing coke in which coal is charged into a coke oven carbonization chamber and subjected to dry distillation. In addition, it is characterized by using one to which 1 mass part or less of coal substantially not containing ash is added. That is, the present invention improves the strength of the obtained coke by using, as charging coal, one obtained by adding 1 part by mass or less of coal containing substantially no ash to 100 parts by mass of raw coal. The point is that the manufacturing process (for example, humidity control process) that affects the strength of the coke is simplified by utilizing the found points and the strength of the obtained coke being improved. For example, since the strength of the coke obtained by conditioning the charge coal and the coal substantially containing no ash is moisture-free coking coal obtained by dry distillation, the humidity conditioning step Coke can be manufactured by simplifying the above.

  As the coal substantially free of ash, a soluble component obtained by extracting an organic solvent from coal having a carbon content (daf) of 60% or more and less than 95% is used. preferable. Preferred examples of the organic solvent include organic solvents containing a bicyclic aromatic compound as a main component. The present invention includes a pig iron manufacturing method characterized by using coke obtained by the above coke manufacturing method.

  “Coal” is generally classified into anthracite, strong caking coal, caking coal, weak caking coal, non-caking coal, lignite, peat, etc., but the definition is not necessarily clear. A part of caking coal may be called adhesive charcoal. Therefore, in the present invention, anthracite coal, strong caking coal, caking coal, weak caking coal, non-caking coal, etc. are classified by carbon content (daf), and anthracite coal is carbon content ( d.af) More than 91% coal, strong caking coal with a carbon content (daf) of 85% or more and 91% or less, caking coal with carbon content (d.a.f.) F.) Is 83% or more and less than 85% coal, weakly caking coal is carbon content (daf) is 80% or more and less than 83% coal, non-caking coal is carbon content (d A.f.) is 78% or more and less than 80% coal, lignite is carbon content (daf) is 70% or more and less than 78% coal, and peat is carbon content (d Af)) less than 70% coal. Here, the carbon content (daf = dry ash free) is the carbon content (% by mass) of organic matter (C, H, O, S, N) excluding moisture and ash content of coal. It can be measured according to JIS M8819. Hereinafter, coal having a carbon content (daf) of 85% or more and 91% or less is simply referred to as “strongly caking coal”, and the carbon content (daf) is 60% or more and 85%. Less than coal may be simply called "non-caking coal etc.".

  According to the method for producing coke of the present invention, coke having improved strength can be obtained. Moreover, the humidity control process can be simplified within a range where the strength of the obtained coke is not substantially lowered.

  The coke obtained by the coke production method of the present invention can be suitably used for the production of pig iron in a blast furnace.

  The coke production method of the present invention is a coke production method in which coal is charged into a coke oven carbonization chamber and dry-distilled. What added 1 mass part or less of is used, It is characterized by the above-mentioned.

(1) About Ashless Coal First, coal that does not substantially contain the ash used in the present invention (hereinafter sometimes referred to as “ashless coal”) will be described. The ashless coal may be coal that does not substantially contain ash, but may contain a small amount of ash. In such a case, the ash content is preferably 5,000 ppm or less, and more preferably 2,000 ppm or less. In addition, ash is a residual inorganic substance when coal is ashed at 815 ° C. and is made of, for example, silicic acid, alumina, iron oxide, lime, magnesia, alkali metal, or the like.

  In the present invention, the ashless coal is obtained by extracting with an organic solvent from coal having a carbon content (daf) of 60% or more and less than 95% (more preferably 60% or more and less than 85%). It is preferable to use a soluble component. A mode in which non-caking coal or the like is effectively used as a starting material is a preferable mode because there is a risk of exhaustion and it is not necessary to use a strong caking coal having a high raw material cost. In a more preferred embodiment, the coal extracted with the organic solvent is a slightly caking coal, a non-caking coal having a carbon content (daf) of 70% or more and less than 83%, and lignite, or these A mixture of

  Specifically, the ashless coal is obtained by mixing coal with an organic solvent having a carbon content (daf) of 60% or more and less than 95% (more preferably 60% or more and less than 85%). A slurry is prepared, the slurry is heated and aged to extract a soluble component in the organic solvent, and the obtained slurry is separated into a supernatant and a concentrated solution in which solid phase components are concentrated, and the supernatant The ashless coal can be obtained by filtering and removing the organic solvent by evaporation. FIG. 1 is an explanatory view illustrating an apparatus and a process for producing ashless coal. In the tank 1, coal having a carbon content (daf) of 60% or more and less than 95% is mixed with an organic solvent to produce a slurry. The obtained slurry is supplied to an extraction tank 4 where an extraction process is performed by a pump 2. At that time, the slurry is heated to a predetermined temperature by the preheater 3. In the extraction tank 4, after the soluble component is extracted into the organic solvent while stirring the slurry using the stirrer 10, the obtained slurry is supplied to the gravity settling tank 5. In the gravity settling tank 5, gravity settling is performed to settle the solid phase component (arrow 11), and the slurry is separated into a supernatant liquid and a liquid in which the solid phase component is concentrated. The obtained supernatant is supplied to the filter unit 8, and the solid phase component concentrate settled in the gravity sedimentation tank 5 is collected in the solid phase component concentrate receiver 6. The supernatant liquid is filtered by the filter member 7 of the filter unit 8, and the obtained filtrate is recovered in a supernatant liquid receiver 9 that recovers the supernatant liquid. Next, ashless coal can be obtained by evaporating and removing the organic solvent from the collected supernatant. As a method for evaporating and removing the organic solvent from the supernatant, a general drying method such as a spray drying method, a distillation method, or a vacuum drying method can be applied.

  The coal concentration in the slurry is suitably 10 to 35% by mass. The conditions for heating and aging the slurry to extract soluble components in the organic solvent include, for example, the slurry at 300 ° C. Hold at ˜420 ° C. for 5 to 120 minutes to solubilize soluble components in the coal. This is because a temperature lower than 300 ° C. is insufficient to weaken the bonds between the molecules constituting the coal, and the proportion of soluble components that can be extracted from the coal decreases. On the other hand, at a temperature higher than 420 ° C., the pyrolysis reaction of coal becomes active, and recombination of the generated pyrolysis radicals occurs, so that the ratio of soluble components that are extracted also decreases. On the other hand, at a temperature of 300 to 420 ° C., bonds between the molecules constituting the coal are loosened, mild pyrolysis occurs, and the proportion of soluble components extracted from the coal increases. At this time, the mild pyrolysis of coal produces an aromatic-rich component mainly having an average boiling point (Tb50: 50% distillation temperature) of 200 to 300 ° C., which is effectively used as a part of the organic solvent. it can.

  The temperature at which the obtained slurry is separated into a supernatant and a solid phase component concentrate by gravity sedimentation is preferably 300 ° C. or higher and 420 ° C. or lower. This is because if it is lower than 300 ° C., a part of the component dissolved in the liquid phase component may be precipitated, and the yield of ashless coal may be reduced.

  As the organic solvent, a solvent having high coal dissolving power is preferable, and an organic solvent containing a bicyclic aromatic compound approximate to a coal structural unit as a main component is preferable. The organic solvent preferably has a boiling point of 180 ° C to 330 ° C. When the boiling point is lower than 180 ° C., the recovery rate of the organic solvent evaporated and removed from the supernatant may be lowered. On the other hand, when the boiling point exceeds 330 ° C., it is difficult to separate the coal and the organic solvent, and the recovery rate of the organic solvent may be lowered. Specific examples of the bicyclic aromatic compound include aliphatics such as naphthalene (boiling point: 218 ° C); methylnaphthalene (boiling point: 241 to 242 ° C), dimethylnaphthalene (boiling point: 261 to 272 ° C), and trimethylnaphthalene. Examples thereof include naphthalene having a side chain; biphenyl; biphenyl having an aliphatic side chain or an aromatic substituent, or a mixture thereof.

  Examples of coal having a carbon content (daf) of 60% or more and less than 95% used as a starting material for producing ashless coal have the following characteristics, for example. It is preferable to use one. The volatile content of the non-caking coal or the like is preferably 30% or more, more preferably 32% or more, preferably 40% or less, more preferably 36% or less. The average reflectance of the non-caking coal or the like is preferably 0.6 or more, more preferably 0.8 or more, preferably 1.0 or less, more preferably 0.9 or less. The total inert such as non-caking coal is preferably 5% or more, more preferably 15% or more, preferably 35% or less, more preferably 20% or less. The Gieseler maximum fluidity (logMFD) such as the non-coking coal is preferably 3.0 (logddpm) or more, more preferably 3.3 (logddpm) or more, preferably 4.5 (logddpm) or less. It is preferably 3.6 (logddpm) or less. The volatile content can be measured by the method specified in JIS M8812, the average reflectance can be measured by the method specified by JIS M8816, and the Gieseler maximum fluidity (logMFD) can be measured by the Gieseler plastometer method specified by JIS M8801. Further, the total inert (TI) is calculated by the following formula using the ratio of semi-fujinite and the ratio of the microstructure component group (maceral group) in the analysis value of the coal microstructure component (maceral) of JIS M8816. be able to.

  In the formula, MM (mineral matter) means a mineral, A means ash (anhydrous base, measured by JIS M8812), and S means a total sulfur content (anhydrous base, measured by JIS M8813).

(2) Coking coal Next, the coking coal used in the present invention will be described. In the present invention, as charging coal, 1 mass part or less, more preferably 0.7 mass part or less, and further preferably 0.5 mass part or less of the ashless coal is added to 100 mass parts of raw coal. It is preferable to use one. Although the minimum of content of ashless coal is not specifically limited, It is preferable that it is 0.2 mass part or more.

  By containing 0.2 parts by mass or more of ashless coal, a substantially significant improvement in the strength of the obtained coke is recognized. In particular, when the content of ashless coal is 0.5 parts by mass, the strength of the obtained coke has the highest value. On the other hand, when the content of ashless coal exceeds 0.5 parts by mass and is 1 part by mass or less, the coke strength is superior to the case where ashless coal is not added, but the content of ashless coal is reduced. As it increases, the resulting coke strength approaches that when no ashless coal is added. And when it exceeds 1 mass part, compared with the case where ashless coal is not added, coke strength will decline on the contrary.

  As the coking coal, for example, a single type or brand of coal, or a mixture of a plurality of types or brands of coal can be used. It is preferable to use charcoal. In addition, since the particle size varies depending on the type and brand of coal, it is preferable to transport the coal in the coal storage yard to a pulverizer and pulverize it so as to have a predetermined particle size.

  Examples of the blended coal include coal having a carbon content (daf) of 85% to 91% and coal having a carbon content (daf) of 60% to less than 85%. A blended charcoal containing is preferred. More preferably, the coal having a carbon content (daf) of 60% or more and less than 85% is a low viscosity having a carbon content (daf) of 78% or more and less than 83%. There may be mentioned carbonized, non-caking coal, or a mixture thereof. As a combination of coal having a carbon content (daf) of 85% to 91% and coal having a carbon content (daf) of 60% to less than 85%, for example, The aspect which consists of a strong caking coal and a weak caking coal, the aspect which consists of a strong caking coal and a non-caking coal, the aspect which consists of a strong caking coal, a weak caking coal, and a non-caking coal are mentioned. Can do.

  Coal having a carbon content (daf) of 85% or more and 91% or less in blended coal is blended in order to increase the strength of the obtained coke. The amount is preferably 10 parts by mass or more, and more preferably 40 parts by mass or more when the entire blended coal is 100 parts by mass. Even if 1 mass part or less of ashless coal is added to 100 mass parts of blended coal because the caking component is too short when the blending amount of strong caking coal is less than 10 mass parts, the desired Coke strength may not be obtained. On the other hand, although the upper limit of the compounding quantity of strong caking coal is not specifically limited, 100 mass parts is preferable, 90 mass parts is more preferable, and 60 mass parts is further more preferable. It is because the raw material cost at the time of coke manufacture will rise when the compounding quantity of strong caking coal increases too much. On the other hand, coal (non-caking coal, etc.) having a carbon content (daf) of 60% or more and less than 85% is blended so that the total blending amount with the strongly caking coal becomes 100 parts by mass. It is preferable.

  In the present invention, the blended coal obtained by blending strongly caking coal and non-caking coal or the like preferably has the following characteristics. The volatile content of the blended coal is preferably 15% or more, more preferably 26% or more, preferably 35% or less, more preferably 29% or less. The average reflectance of the blended charcoal is preferably 0.65 or more, more preferably 1.00 or more, preferably 1.60 or less, more preferably 1.10 or less. The total inert of the blended coal is preferably 15% or more, more preferably 20% or more, preferably 35% or less, more preferably 23% or less. The Gieseler maximum fluidity (logMFD) of the blended coal is preferably 0.7 (logddpm) or more, more preferably 2.0 (logddpm) or more, preferably 3.5 (logddpm) or less, more preferably 2 .3 (logddpm) or less. The particle size constitution of the blended coal is preferably 3 mm or less, preferably 50% or more, more preferably 75% or more, preferably 90% or less, more preferably 85% or less. The wide numerical range of each characteristic is a suitable range that can be used as a raw material for blast furnace coke, and by making each characteristic within a narrower numerical range, there is a coke that is substantially insignificant in strength. can get.

(3) About coke manufacturing process The manufacturing method of the coke of this invention is what added 1 mass part or less of the said ashless coal with respect to 100 mass parts of said raw coal as charging coal, in a coke oven carbonization chamber. Charge and dry distillation.

  In general, in the production of coke, raw coal is conditioned and the moisture content is adjusted as charging coal. This is because if the water content of the charged coal is too large, an excessive amount of heat is required during dry distillation, which is not economical, and also causes variations in quality. According to the present invention, the strength of the obtained coke is improved by adding ashless coal to the raw coal. Therefore, the humidity control step that affects the obtained coke strength can be modified as follows.

  Humidity-conditioned one is used as the charging coal. That is, if the conditioned coal is used as the charging coal, the strength is higher than the strength of coke obtained by using the ashless coal conditioned to the same degree as the additive raw coal. Improved coke is obtained.

  For example, the strength of coke obtained by adding the ashless coal is improved even when the moisture content is adjusted to 7% to 9%, and the moisture content is about 5% to 7%. Coke having almost the same strength as coke obtained by dry distillation of raw coal (no coal distribution added) is obtained. As described above, the use of coking coal having a water content of about 5% to 7% causes a problem of scattering of fine coal powder. According to the present invention, the water content is about 7% to 9%. By using this coking coal, coke having substantially the same strength as coke obtained by dry distillation of coking coal having a water content of about 5% to 7% can be obtained.

  Even if it is 7% -9% raw coal with a relatively high water content, by adding the ashless coal, the coke obtained by dry distillation of about 5% -7% raw coal is almost the same as coke. Since coke having the same strength can be obtained, it is not necessary to adjust the moisture content (7-9%) of the raw coal. Moreover, you may reduce the degree of humidity control. Since moisture is removed by heat energy in the humidity adjustment process, substantially omitting the humidity adjustment process is an economically very advantageous manufacturing method.

In the present invention, charged coal in which 1 part by mass or less of ashless coal is added to 100 parts by mass of raw coal is charged into a coke oven carbonization chamber and subjected to dry distillation. The packing density when charging the coal into the carbonization chamber is not particularly limited. For example, 600 kg / m ³ or more is preferable, 650 kg / m ³ or more is more preferable, 1000 kg / m ³ or less is preferable, and 850 kg / m. ³ or less is more preferable. When the packing density is less than 600 kg / m ³ , the voids of the powder layer are filled with the weight of the coal itself, and it is substantially difficult to make it less than this value, and the packing density exceeds 1000 kg / m ³ . In this case, it is substantially difficult to fill the voids of the powder layer to a value higher than this value and to compact the powder layer.

It should be noted that the charging density of the charging coal is related to the above-described moisture content when the operation of mechanically compacting is not performed, and in general, the more the charging coal having a low moisture content is used, the more the carbonization chamber is. For example, when coal having a moisture content of about 7% is used, the packing density into the coke oven carbonization chamber is usually about 720 kg / m ³ .

  The conditions for carbonizing the charging coal are not particularly limited, and normal carbonization conditions in coke production using a coke oven can be adopted, for example, 950 ° C. or higher, more preferably 1000 ° C. or higher, It is preferable to perform carbonization at a temperature of 1200 ° C. or lower, more preferably 1050 ° C. or lower, for 8 hours or longer, more preferably 10 hours or longer, more preferably 24 hours or shorter, more preferably 20 hours or shorter.

(4) Method for producing pig iron The present invention includes a method for producing pig iron characterized by using coke obtained by the method for producing coke according to the present invention. Since the coke obtained by the production method of the present invention is excellent in strength, it can be suitably used for producing pig iron in a blast furnace. That is, if coke obtained by the production method of the present invention is used, gas permeability at the time of pig iron production in a blast furnace is improved. Further, in a mode in which the humidity control step is omitted or the degree of humidity control is reduced, cheap coke can be obtained. The pig iron production method in the blast furnace may be a known method. For example, iron ore and coke are alternately layered in the blast furnace, and hot air from the bottom of the blast furnace, and if necessary, pulverized coal. Can be mentioned.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and all modifications and embodiments without departing from the gist of the present invention are not limited thereto. Included in range.

  As shown in Tables 1 and 2, ashless coal was added to the blended coal to prepare charging coal. As ashless coal, a soluble component (ash content: 600 ppm) extracted from Australian caking coal (carbon content (daf) 84%) using 1-methylnaphthalene was used. In addition, the ashless charcoal was prepared with the following method using the apparatus of FIG. Australian caking coal (carbon content (daf) 84%) and 1-methylnaphthalene were mixed in tank 1 (Australian caking coal: 1-methyltaphthalene = 20% by mass: 80 (Mass%) slurry was prepared. The obtained slurry was heated to 370 ° C. by the preheater 3, and soluble components were extracted from the caking coal produced in Australia in the extraction tank 4. The slurry after the extraction treatment is supplied to the gravity sedimentation tank 5 at a flow rate of 15 kg / h, gravity sedimentation is performed, and the supernatant liquid and the solid phase component concentrate are separated. The supernatant liquid is filtered at a flow rate of 3 kg / h. The solid phase component concentrate was discharged from the bottom of the gravity sedimentation tank 5 to the solid phase component concentrate receiver 6 at a flow rate of 12 kg / h. The supernatant liquid was filtered by the filter unit 8 and then collected in the supernatant liquid receiver 9, and the organic solvent was removed by evaporation from the collected liquid by spray drying to obtain ashless charcoal (ash content: 600 ppm).

  The charged coal was filled in a can container having a size of 378 mm wide × 121 mm long × 114 mm high so as to have a desired filling density. Four of these cans are placed in a steel retort (size: width 380 mm × length 430 mm × height 350 mm), and the retort is placed in a double-sided heating electric furnace that can heat the cans in the width direction. The charge coal was carbonized. The dry distillation was performed at 1000 ° C. for 10 hours, and then the retort was taken out of the electric furnace and allowed to cool naturally over about 16 hours.

  Four can containers were taken out from the cooled retort, and a 189 mm portion of coke corresponding to half in the width direction was cut out. When performing double-sided heating, the place that hits the middle in the width direction is called a charcoal core, and the calcined coke from the heating surface to the charcoal core is called the head, body, tail from the place close to the heating surface, It is known that a difference in strength occurs due to a difference in heating rate during heating of the head, body, and tail. For this reason, the coke head, body, and tail of the 189mm portion corresponding to half of the width direction are cut into approximately cuboids (one side: approximately 20mm ± 1mm) from each part divided into approximately 60mm and sized. Got coke. The sized coke was washed with distilled water to remove fine coke powder adhering during sizing (at the time of cutting), and dried with a dryer at 150 ° C. ± 2 ° C.

Using the obtained strength measurement sample, the I-type strength was measured. As a device used for the type I strength test, a cylindrical container made of SUS material (length: 720 mm, circular bottom diameter: 132 mm) is used, and 200 g of the sample is put in this container, and rotated 20 times per minute. It was rotated at a speed for 30 minutes, and an impact due to a total of 600 rotational motions was applied. The rotation of the cylinder was performed such that a rotation axis was provided at a position of 360 mm corresponding to the middle of the cylinder length of 720 mm, and the cylinder was rotated around the rotation axis so that the bottom surface of the cylinder drawn a circle with a diameter of 720 mm. After applying an impact by the specified 600 rotations, a sample was taken out from the cylindrical container, and divided by a 9.5 mm sieve to measure the mass on the sieve. At this time, the mass caught on the sieve was also measured on the sieve and the mass was measured. The type I strength index was calculated as follows, and the calculated results are shown in Tables 1 and 2.
Type I strength index I ⁶⁰⁰ _9.5 = 100 × 9.5 mm Mass on sieve (unit: g) / 200 g

In general, the rotational strength of coke is classified into one that evaluates volume fracture in which a coke lump is broken as a large lump and one that evaluates surface breakage due to surface wear, but is the type I used in the present invention. The strength index I ⁶⁰⁰ _9.5 is interpreted as an index used to evaluate surface fracture.

  From the results in Table 1, coke no. 1 to No. 7 is compared, it turns out that the coke intensity | strength obtained improves by adding 1 mass part or less of ashless coal with respect to 100 mass parts of blended coal. In particular, the coke strength obtained when 0.5 parts by mass of ashless coal was added to 100 parts by mass of blended coal was the largest. In addition, coke No. 6 and no. From the result of 7, it can be seen that when the addition amount of ashless coal exceeds 1 part by mass with respect to 100 parts by mass of the blended coal, the coke strength is decreased.

From the results in Table 2, the strength of the coke obtained by using the charging coal added with 0.5 parts by mass of ashless coal and having the charging coal filling density adjusted to 720, 740 kg / m ³ ( Coke Nos. 8 and 9) are coke strengths obtained by using charging coals with no addition of ashless coal and adjusting the charging coal packing density to 745 and 760 kg / m ³ , respectively. It can be seen that it is equal to (Coke No. 10, 11). In addition, when compared with the case where ashless coal is not added and the case where 0.5 part by mass of ashless coal is added, the coke strength obtained by using the charging coal added with 0.5 part by mass of ashless coal Is high.

  From these results, if the conditioned coal is used as the charging coal, compared to the strength of coke obtained by using the ashless coal conditioned to the same degree as the raw coal without additive, It can be confirmed that coke with improved strength is obtained. In addition, if the coke having a strength approximately the same as the strength of coke obtained by using ashless charcoal that has been conditioned as usual without additive raw coal, as the charging coal, It can be seen that it may be used without substantially adjusting the humidity or with a reduced degree of humidity adjustment.

  The present invention can be suitably applied to the production of coke and pig iron.

Explanatory drawing which illustrates the apparatus and process which manufacture ashless coal used by this invention.

Explanation of symbols

1: tank, 2: pump, 3: preheater, 4: extraction tank, 5: gravity sedimentation tank, 6: solid phase component concentrate receiver, 7: filter member, 8: filter unit, 9: supernatant receiver 10: Stirrer, 13: Stirrer

Claims (5)

In a coke production method in which coal is charged into a coke oven carbonization chamber and carbonized,
A method for producing coke, characterized in that, as charging coal, 1 mass part or less of coal containing substantially no ash is added to 100 mass parts of raw coal.   The method for producing coke according to claim 1, wherein the charging coal is used without being substantially conditioned or having a reduced degree of humidity adjustment.   The soluble component obtained by extracting from an coal having a carbon content (daf) of 60% or more and less than 95% with an organic solvent is used as the coal substantially free of ash. Or the manufacturing method of the coke of 2.   The method for producing coke according to claim 3, wherein the organic solvent is an organic solvent containing a bicyclic aromatic compound as a main component.   A method for producing pig iron, wherein coke obtained by the method for producing coke according to any one of claims 1 to 4 is used.

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