JP2007321076A - Caking filler having excellent characteristics of increasing strength and process for producing high-strength coke - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a caking filler that can ensure strength in terms of DI<SP>150</SP><SB>15</SB>of not less than 84.5 and that in terms of CSR of not less than 62 even if the blending ratio of a non-caking coal and/or a slightly-caking coal to a raw material coal exceeds 20%, and to provide a process for producing high-strength coke using the caking filler. <P>SOLUTION: The caking filler having excellent characteristics of increasing strength is a caking filler blended into a raw material coal for producing high-strength coke, which comprises 45-84% of a hexane-soluble component (HS component), 15-54% of a hexane-insoluble and toluene-soluble component (HITS component), 1-40% of a toluene-insoluble component (TI component) and the balance being a residual component unavoidably produced and has an atomic ratio of H to C of 0.95-1.10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a caking filler that acts to enhance the strength of coke, and more particularly, to a method for producing high-strength coke using a petroleum heavy fraction.

  In blast furnace operation, the reducing material coke is required to have a required strength in order to ensure air permeability in the furnace. In order to produce high-strength coke, high-quality strong caking coal is required as coking coking coal, but the high-quality caking coal is in a resource-depleted state for a long time.

  Therefore, many methods have been proposed so far for producing high-strength coke using low-quality non-coking coal as raw coal.

  When using low quality non-caking coal as raw coal, caking filler is added and mixed in order to compensate for caking properties. For example, tar, pitch, petroleum-based caking material, or the like is used as caking filler (see Patent Documents 1 to 3).

  In Patent Document 1, a petroleum-based heavy fraction such as asphalt is added to raw coal, the blending ratio of caking coal is reduced, the blending ratio of non-caking coal is increased, and high-quality coke is produced. A method is disclosed.

  In Patent Document 2, asphalt having a softening point of 100 ° C. or higher obtained from petroleum heavy oil using butane, pentane or hexane as a solvent alone or in combination is used as a raw coal. A method for producing coke to add and mix parts by weight is disclosed.

However, in these production methods, the coke strength index DI ¹⁵⁰ ₁₅ cannot ensure the minimum level of 84.5 necessary for blast furnace coke. Further, the blending ratio of non-slightly caking coal is as low as 0% in Patent Document 1 and 9 to 13% in Patent Document 2.

  On the other hand, as one of the methods to obtain high strength coke by using a large amount of non-slightly caking coal, the coal is dried before charging into the coke oven, and the bulk density of the coal charged into the coke oven is improved. A process called a humidified coal method is widely used in Japan (see Patent Document 4). However, in the modified coal method, a caking filler that effectively improves coke strength, and the caking supplement There is no known production method capable of producing high-strength coke using a material.

  Accordingly, the present applicant aims to produce high-strength coke for blast furnaces, and in Patent Document 3, a heavy tar fraction is added as a caking filler to coking coal containing 0-60 wt% of non-minor caking coal. A method for producing coke for blast furnace was proposed.

In this production method, tar is distilled at 200 to 350 ° C., hexane soluble component (HS) is 20 wt% or less, component insoluble in hexane and soluble in toluene (HITS) is 40 to 80 wt%, insoluble in toluene. For heavy blast furnaces where DI ¹⁵⁰ ₁₅ is 83-84 in a high range of 40-60% when the heavy tar fraction with component (TI) adjusted to 0-40 wt% is used. Coke production is possible. However, when a heavy tar fraction is used as a caking additive, coke strength after hot reaction (hereinafter referred to as “CSR”) required for coke strength after dry distillation (DI ¹⁵⁰ ₁₅ ) as a raw material for blast furnace charging. ) Was not fully satisfied.

The coke CSR is an index indicating the strength after reaction in the blast furnace, and 200 g of coke adjusted to a size of 20 ± 1 mm is obtained from gas composition: carbon dioxide (100%), reaction temperature 1100 ° C., reaction time. It is defined as the percentage of the mass on the 9.56 mm screen relative to the post-reaction mass after reacting for 2 hours, followed by 600 revolutions with a type I drum. In order to suppress coke pulverization after reaction in the blast furnace and to maintain good air permeability in the furnace as a spacer between iron ore layers, high CSR is required. In the case where a large amount of non-slightly caking coal is used as the raw coal, the conventional caking material method has a CSR of 62 even if DI ¹⁵⁰ ₁₅ can secure a high cold coke strength of 84.5 or more. It was difficult to ensure sufficient strength after the above high hot reaction.

Therefore, even if a large amount of non-slightly caking coal is used, DI ¹⁵⁰ ₁₅ ensures sufficient cold coke strength of 84.5 or more, and CSR ensures high post-hot reaction strength of 62 or more. There is a strong demand for coke production technology.

  On the other hand, petroleum heavy fractions (for example, deasphalted asphalt) are by-products when separating and refining light oil from crude oil, and their effective use is considered together with coal-based heavy fractions such as tar. Has been. In the past, most of the heavy petroleum fractions were used as fuel, but compared to heavy coal fractions such as tar, petroleum heavy fractions contain sulfur components contained in crude oil. And heavy metal components such as vanadium are concentrated at high concentrations. For this reason, when using petroleum heavy fractions as fuel, flue gas desulfurization equipment and combustion facilities with high temperature corrosion countermeasures such as vanadium are required, and combustion ash waste containing heavy metals is also required. There were problems such as environmental problems.

  In recent years, the use of petroleum heavy fractions as a caking filler similar to coal heavy fractions such as tar has also been studied in coke production processes. In general, in the coke production process, even if the sulfur concentration in the pyrolysis gas (coke oven gas) generated during coke production increases due to the sulfur component in the caking filler, the accompanying coke oven gas purification equipment Since it is desulfurized, it is advantageous in terms of equipment costs.

  However, heavy metal components such as sulfur components and vanadium increase in coke due to the sulfur components in the caking filler and vanadium, and there is a concern that the hot metal quality in the blast furnace will deteriorate. For this reason, when petroleum heavy fraction is used in the coke production process as a caking filler, it is required that there is no deterioration in hot metal quality in the blast furnace due to heavy metal components such as sulfur components and vanadium. The

  In the coke manufacturing process, oil such as tar, which is a by-product other than coke products, and part of coke oven gas are effectively used as chemical raw materials and combustion gas. For this reason, when petroleum heavy fraction is used as a coking filler in the coke production process, it affects the oil content such as tar and the quality of coke oven gas caused by heavy metal components such as sulfur and vanadium. It is also required that there is no.

Coal chemistry and industry (Sankyo Publishing Co., Ltd., 1977 edition, p.315) JP 59-179586 A JP-A-9-241653 Ferrum Vol. 9 (2004), p. 810

In view of the above demand, in the production of blast furnace coke, the present invention has a DI ¹⁵⁰ ₁₅ of 84.5 or more and a CSR of 62 or more even when the blending ratio of non-slightly caking coal in the raw coal exceeds 20%. It is a first object to provide a caking filler capable of securing strength and a manufacturing method for producing high-strength coke using the caking filler.

  In addition, the present invention provides a hot metal quality in a blast furnace due to residual heavy metal components such as sulfur components and vanadium in coke when producing coke using a heavy petroleum-based fraction as a caking filler for blended raw materials. The second problem is to provide a method for producing coke having good quality that does not affect the quality of oil and coke oven gas, which are by-products of the coke oven.

  As the proportion of non-slightly caking coal in the coking coal increases, the caking property as a coking coal naturally decreases. Therefore, in order to produce high-strength coke, the viscosity that can compensate for this causticity reduction is compensated. It is necessary to add a predetermined amount of the binding filler to the raw coal.

  As described above, tar, heavy tar fraction, coal-based pitch, petroleum-based heavy fraction (eg, deasphalted asphalt) and petroleum-based pitch are effective as caking fillers that enhance coke strength. To work.

  However, in the case of using a large amount of non-slightly caking coal, or when using various types of non-slightly caking coal in various blends, in order to sufficiently bring out the strength enhancement effect of the caking filler, It is necessary to know the properties and the properties of the caking filler, and to select and blend the caking filler that matches the properties of the raw coal.

  As a caking filler, the present inventor obtained a petroleum pitch obtained by separating light oil from petroleum heavy oil by thermal reforming by hydrogenation reforming reaction and then separating the resulting light oil. Focusing on the component composition of the HS component, HITS component, and TI component in the resulting residue, and the H / C atomic ratio, the relationship between these and the strength enhancement effect of coke was investigated.

As a result, depending on the properties of the raw coal, if a predetermined amount of the caking filler whose component composition of the HS component, the HITS component, and the TI component and the H / C atomic ratio are adjusted is blended, DI ¹⁵⁰ ₁₅ 84 It has been found that high strength coke of 5 or more and 62 or more by CSR can be produced.

This invention was made | formed based on the said knowledge, and the summary is as follows.
(1) A caking filler to be mixed with raw coal to produce high-strength coke, which is soluble in hexane (HS component): 45 to 84%, insoluble in hexane and soluble in toluene ( HITS component): 15 to 54%, and a component insoluble in toluene (TI component): 1 to 40%, the remainder consists of inevitable residual components, and the H / C atomic ratio: 0.95 to 1 10. A caking filler excellent in strength enhancement characteristics, characterized by being 10.

  In addition, content of each component of a caking filler is mass%, and it is the same also in the following description.

(2) A caking filler compounded in raw coal to produce high-strength coke, which is soluble in hexane (HS component): less than 45%, insoluble in hexane and soluble in toluene (HITS) Component): 15 to 99%, and a component insoluble in toluene (TI component): 1 to 85%, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.85 to 1. A caking filler excellent in strength enhancement characteristics characterized by being 10.

(3) The caking filler having excellent strength enhancement characteristics as described in (1) or (2) above, wherein the raw coal contains more than 20% by mass of non-slightly caking coal.

(4) In the method of producing high-strength coke by dry distillation of raw coal, a component soluble in hexane (HS component) in the raw coal: 45 to 84%, a component insoluble in hexane but soluble in toluene (HITS) Component): 15 to 54%, and a component insoluble in toluene (TI component): 1 to 40%, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.95 to 1. A method for producing high-strength coke, which comprises blending a caking filler of 10.

(5) In the method of producing high-strength coke by dry distillation of raw coal, a component soluble in hexane (HS component) in the raw coal: less than 45%, a component insoluble in hexane but soluble in toluene (HITS component) ): 15 to 99%, and a component insoluble in toluene (TI component): 1 to 85%, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.85 to 1.10. A method for producing high-strength coke, characterized in that it contains a caking filler having excellent strength enhancement characteristics.

(6) The method for producing high-strength coke according to (4) or (5) above, wherein the raw coal contains more than 20% by mass of non-slightly caking coal.

(7) The method for producing high-strength coke according to any one of (4) to (6), wherein the caking filler is blended in an amount of 0.2 to 5% by mass with respect to the raw coal. .

According to the present invention, the petroleum component obtained by separating light oil from petroleum-based heavy oil is thermally reformed by hydrogenation reforming reaction, and then obtained by separating the resulting light oil, HS component: 45 to 84%, HITS component: 15 to 54%, TI component: 1 to 40%, and H / C atomic ratio: 0.95 to 1.10, or HS component: less than 45%, HITS component: 15 -99%, TI component: 1-85%, and H / C atomic ratio: 0.85 to 1.10 heavy petroleum residue is blended into raw coal as a binder according to the properties of raw coal Thus, high strength coke having DI ¹⁵⁰ ₁₅ of 84.5 or more and CSR of 62 or more can be produced.

  In addition, the heavy oil-based fraction generated in large quantities when light oil is separated and refined from crude oil is effectively used as a caking additive for coke production to produce high-strength coke for blast furnaces. In addition to great value, it also has great social significance in terms of environmental protection.

  The present invention will be described in detail. In general, heavy petroleum residues are mainly composed of a component soluble in hexane (hereinafter sometimes referred to as “HS component”), a component insoluble in hexane and soluble in toluene (hereinafter sometimes referred to as “HITS component”), and It consists of a component insoluble in toluene (TI component) and other inevitable residual components.

FIG. 1 is a composition diagram in which the composition of the HS component, the HITS component, and the TI component is taken on each side. The inventor of the present invention, among heavy petroleum residues, in FIG. 1, a region surrounded by a solid line (region of symbols “a” + “b”), that is, HS component: 84% or less, HITS component: 15% or more, Focusing on heavy petroleum residues in the region of TI component: 1 to 85%, coke strength after dry distillation (DI ¹⁵⁰ ₁₅ ) and coke strength after hot reaction (hereinafter referred to as “CSR”) are improved. The component composition of the caking filler with excellent strength enhancement characteristics for the production of coke obtained was studied in detail.

According to the study by the present inventors, in ensuring the coke strength (DI ¹⁵⁰ ₁₅ ) after dry distillation, in the pore structure of coke, (a) the pore size is appropriate, and (b) the pore shape is It is important that the surface is round and (c) the coke wall is thick. To ensure the strength of the coke after hot reaction (CSR), (d) the coke surface develops anisotropy. It is important that the carbon structure is small and that there are few micropores, the composition of the HS component, the HITS component and the TI component in the caking filler, and the H / C atomic ratio (the atomic ratio of hydrogen to carbon) Was experimentally confirmed to have the following effect.

  (A) The HS component (light component) is gasified during the dry distillation process, promotes the growth and coalescence of bubbles in the softened and melted coal, and increases the pore size to an appropriate size (pore expansion action).

  (B) The HITS component (intermediate component) reduces the viscosity of the coal softened and melted during the dry distillation process, and makes the shape of the bubbles round (pore rounding action).

  (C) The TI component (heavy component) is almost a residue, but thickens the coke wall (wall thickness increasing action).

  (D) A caking filler having a high H / C atomic ratio has a structure with more aliphatic side chains, the side chains are preferentially broken during thermal decomposition, and a side chain-derived molecule having a radical structure (carbonization) Hydrogen molecules) cause a polymerization reaction and a dehydrogenation reaction on the surface of the coke to change to a carbon structure with developed anisotropy or to seal micropores.

  Furthermore, as a result of examining the coke strength improvement effect due to the properties of the raw coal and the action of the caking filler, the composition of the HS component, the HITS component, and the TI component in the caking filler according to the properties of the raw coal It was confirmed that a significant coke strength enhancement effect was obtained by adjusting the H / C atomic ratio.

That is, as a result of the study by the present inventors, the following was found.
In general, non-caking coal is a coking coal with low caking properties (expandability specified by JIS) and a large amount of volatile matter, but relatively non-caking coal (expandability specified by JIS). For low coke and high volatile content, caking filler to exert effect to improve both coke strength after dry distillation (DI ¹⁵⁰ ₁₅ ) and strength after hot reaction of coke (CSR) It was found that the composition of the components was different.

(X) Compared to raw coal with low caking properties (expandability specified in JIS), there are relatively many HS components (light components) that perform pore expansion, and the H / C atomic ratio (number of hydrogen and carbon atoms) When a caking filler having a relatively high ratio is added, both the coke strength after dry distillation (DI ¹⁵⁰ ₁₅ ) and the strength after hot reaction of coke (CSR) can be improved.

(Y) When coking coal after dry distillation is added to coking coal with a large amount of volatile matter, the addition of a caking filler that has a relatively small HS component (light component) and a relatively low H / C atomic ratio. Both strength (DI ¹⁵⁰ ₁₅ ) and coke strength after hot reaction (CSR) can be improved.

  And this inventor is the component composition of HS component: 45-84%, HITS component: 15-54%, and TI component: 1-40% as a caking filler which satisfy | fills said (x) (FIG. 1). A caking filler A having a composition range of “a” in the middle) and an H / C atomic ratio of 0.95 or more and 1.10 or less was found.

When adding caking filler A having a content of HS component (light component) of less than 45% to coking coal with low caking properties (expandability specified in JIS), the action of the HS component The strength enhancement effect by cannot be obtained. In particular, in order to improve the coke strength (DI ¹⁵⁰ ₁₅ ), the lower limit of the content of the HS component (light component) in the caking filler A is set to 45%. On the other hand, when the content of the HS component exceeds 84%, the size of the pores formed in the coke becomes too large, the wall thickness becomes thin, and conversely, the coke strength (DI ¹⁵⁰ ₁₅ ) after dry distillation decreases. Therefore, the upper limit of the content of the HS component is set to 84%.

The content of the HITS component (intermediate component) in the caking filler A reduces the viscosity of the coal softened and melted during the dry distillation process, and improves the coke strength (DI ¹⁵⁰ ₁₅ ) due to the rounding action of the coke pores. It is necessary to make it 15% or more in order to gain. On the other hand, if the content of the HITS component exceeds 54%, the pore rounding action is saturated and the required strength enhancement effect cannot be obtained.

When the TI component (heavy component) in the caking filler A is less than 1%, the wall thickness increasing action is not obtained regardless of the addition amount of the HS component and / or the HITS component. The effect of improving the strength (DI ¹⁵⁰ ₁₅ ) cannot be obtained. On the other hand, if the content of the TI component exceeds 40%, the other components must be reduced, and the required strength enhancement effect cannot be obtained.

While satisfying the component composition of the above HS component, HITS component, and TI component, by defining the H / C atomic ratio in the following range, the coking coal has a low caking property (expandability defined by JIS). When the caking filler A is added, in addition to the coke strength after dry distillation (DI ¹⁵⁰ ₁₅ ), the strength after hot reaction (CSR) of the coke can be further improved.

  According to the study by the present inventors, the caking filler having a high H / C has a structure having more aliphatic side chains, the side chains are preferentially broken during thermal decomposition, and have a radical structure. Chain-derived molecules (hydrocarbon molecules) are trapped on the surface of coke, and are liable to cause polymerization reaction and dehydrogenolysis. As a result, the strength of the coke after hot reaction (CSR) is improved by modifying the coke surface to a carbon structure with developed anisotropy, or by depositing in the micropores of the coke and sealing the micropores. There is an effect of improving. Further, the H / C atomic ratio of the caking filler tends to increase as the HS component (light component) increases, and in the case of caking filler A, the H / C atomic ratio in the caking filler. Is 0.95 or more, the effect of improving the strength after hot reaction (CSR) of the coke can be obtained.

  On the other hand, when the H / C atomic ratio of the caking filler is higher than 1.10, the aliphatic side chains are thermally decomposed at a lower temperature and trapped on the coke surface before the polymerization reaction and dehydrogenation decomposition occur. The effect of sealing out the micropores on the coke surface is reduced. Therefore, the H / C atomic ratio needs to be 0.95 to 1.10 in order to sufficiently exhibit the effect of improving the strength after hot reaction (CSR) of coke.

  Moreover, as a caking filler which satisfy | fills said (y), the component composition of HS component: less than 45%, HITS component: 15-99%, and TI component: 1-85% (composition of "b" in FIG. 1) Region) and an H / C atomic ratio of 0.85 to 1.10 was found.

When caking filler B having an HS component content of 45% or more is added to coking coal with a large amount of volatile matter, the size of pores formed in coke becomes too large and the wall thickness is thin. As a result, the coke strength (DI ¹⁵⁰ ₁₅ ) decreases. For this reason, the upper limit of HS component content in the caking filler B is made into less than 45%.

The content of the HITS component (intermediate component) in the caking filler B reduces the viscosity of coal softened and melted during the dry distillation process, and improves the coke strength (DI ¹⁵⁰ ₁₅ ) due to the rounding action of coke pores. It is necessary to make it 15% or more in order to gain. On the other hand, when the content of the HITS component exceeds 99%, the pore rounding action is saturated and the required strength enhancement effect cannot be obtained.

If the TI component (heavy component) in the caking filler B is less than 1%, the wall thickness increasing action cannot be obtained, and the required coke strength (DI ¹⁵⁰ ₁₅ ) improving effect cannot be obtained. On the other hand, if the content of the TI component exceeds 85%, the other components must be reduced, and the required strength enhancement effect cannot be obtained.

  In the case of the caking filler B, when the H / C atomic ratio in the caking filler is 0.85 or more, the effect of improving the strength after hot reaction (CSR) of the coke can be obtained. On the other hand, when the H / C atomic ratio of the caking filler is higher than 1.10, the aliphatic side chains are thermally decomposed at a lower temperature and trapped on the coke surface before the polymerization reaction and dehydrogenation decomposition occur. The effect of sealing out the micropores on the coke surface is reduced. Therefore, in order to fully exhibit the effect of improving the strength after hot reaction (CSR) of coke, the H / C atomic ratio needs to be 0.85 to 1.10.

  The binder having the component composition of the HS component, the HITS component, and the TI component as described above and satisfying the H / C atomic ratio can be manufactured as follows.

  First, light oil is separated from petroleum heavy oil by solvent extraction or distillation to obtain petroleum pitch.

  When light oil is separated from petroleum heavy oil by solvent extraction treatment, it is preferable to use butane, pentane, hexane, or heptane alone or in combination as an extraction solvent. In addition, the volume flow ratio of the extraction solvent and petroleum heavy oil in the solvent extraction process (solvent / petroleum heavy oil) is 2 or more in order to increase the separation efficiency of light oil such as paraffin in the petroleum heavy oil. Is preferable.

  On the other hand, if the volume flow ratio of the extraction solvent and heavy petroleum oil is larger than 10, the amount of the extraction solvent used increases and the scale of the process increases. Expenses for each process such as cooling increase. Therefore, the volume flow rate ratio of the extraction solvent and the petroleum heavy oil in the solvent extraction treatment is preferably 2-10.

  When light oil is separated from petroleum heavy oil by distillation, the cut point is preferably 500 ° C. or higher in order to efficiently separate paraffin in the petroleum pitch together with light oil. Similarly, lowering the pressure is more desirable because more paraffin in the heavy petroleum oil can be separated together with the light oil.

  On the other hand, when the cut point is excessively higher than 600 ° C., part of the petroleum heavy oil is thermally decomposed, gas is generated or carbon is deposited, the distillation apparatus is loaded, and the process stability is low. Therefore, the cut point is preferably 600 ° C. or lower. For these reasons, the cut point in the distillation treatment is preferably 500 to 600 ° C.

  Next, petroleum pitch obtained by separating light oil from petroleum heavy oil by the above-described solvent extraction treatment or distillation treatment is subjected to hydrogenation reforming treatment, and the generated light oil is separated.

  The petroleum pitch hydrotreating treatment is carried out in the presence of hydrogen and an additive having hydrogenation ability to promote the breaking of hydrocarbon carbon-carbon bonds, carbon-sulfur bonds, and carbon-nitrogen bonds.

  As an additive having hydrogenation ability, it is preferable that an additive containing at least one selected from iron, nickel, cobalt, molybdenum and tungsten is allowed to coexist in order for the hydrogen reforming reaction to proceed smoothly. Nickel, cobalt, molybdenum and tungsten metals used as additives may be used in any form of simple metal, organic compound and inorganic compound. Furthermore, simple metal, organic compound and inorganic compound include alumina, silica, It may be supported on a carrier such as titania or used in a state dispersed in a solution.

  In addition, the temperature condition of the hydrogenation reforming reaction is more likely to proceed as the reaction temperature is higher. However, if the reaction temperature is excessively increased, the carbon component is precipitated in the reactor and the piping attached thereto, and the precipitated carbon is further precipitated. Minutes adhere to the additive surface and hinder the progress of the reaction.

  In addition, the pressure condition and the flow rate ratio of hydrogen / petroleum pitch in the hydroreforming reaction are suppressed as the pressure and the flow rate ratio of hydrogen / petroleum pitch are increased in order to suppress the deposition of carbon, but are excessively large. Then, expenses for each process such as heating, cooling, compression, and transfer of raw materials increase, leading to an increase in cost.

Therefore, in the hydrogenation reforming reaction of the present invention, the reaction temperature is 380 to 500 ° C., the pressure is 80 to 250 kg / cm ² , and the hydrogen / petroleum pitch is used in order to suppress the precipitation of carbon components and the reaction proceeds smoothly. The flow rate ratio is 1000 to 3000 Nm ³ / m ³ , more preferably, the reaction temperature is 400 to 480 ° C., the pressure is 120 to 210 kg / cm ² , and the hydrogen / petroleum pitch flow ratio is 1500 to 2500 Nm ³ / m. ^It is good to carry out under the condition of ³ .

In the present invention, if the amount of the caking filler added to the raw coal is less than 0.2% by mass, it is difficult to sufficiently exhibit the above effect by the caking filler, and the desired coke strength after dry distillation ( DI ¹⁵⁰ ₁₅ ) and coke strength after hot reaction (CSR) cannot be achieved. Therefore, the addition amount of the caking filler relative to the raw coal is preferably 0.2% by mass or more.

  In addition, when petroleum heavy fractions are used in the coke production process as a caking filler for blended raw materials, heavy components such as sulfur and vanadium in crude oil have high concentrations in petroleum heavy fractions. Since it is concentrated, there is a concern that it will remain in the coke. About half of the sulfur component in the caking filler is transferred into the pyrolysis gas (coke oven gas) in the coke oven, and desulfurized by the accompanying coke oven gas purification equipment. On the other hand, most of heavy metal components such as vanadium in the caking filler remain in the coke. When the coke is used in the blast furnace, most of the sulfur component and heavy metal components remaining in the coke are transferred into the slag generated in the blast furnace, and are removed and separated from the hot metal.

  According to the study by the present inventors, when producing coke using a heavy petroleum fraction as a caking filler, the blending ratio of caking filler to the raw coal is set to 5% or less. It has been confirmed that coke having a good quality can be produced without any influence on the quality of the hot metal in the blast furnace due to the residue of heavy metal components such as sulfur components and vanadium. In addition, since the residue of heavy metal components such as sulfur and vanadium in coke is reduced as the blending ratio of caking filler to raw coal is reduced, the blending ratio of caking filler to raw coal is reduced from this point. Is preferably 2% or less.

  Also, the sulfur component concentration in the coke oven gas is increased by shifting the sulfur component in the caking filler into the pyrolysis gas during coke production. It has also been confirmed that the existing coke oven gas purification equipment associated with the process can be sufficiently desulfurized during normal operation without modification.

  In the present invention, since the coke strength is increased by blending a caking filler having a required component composition, the blending amount of non-slightly caking coal is not limited.

  Usually, when the blending amount of the non-slightly caking coal is 20% by mass or more, the coke strength is remarkably lowered. However, the present invention has a remarkable effect even when the blending amount of the non-slightly caking coal is 20% by mass or more. Demonstrate. In the present invention, the particle size distribution and properties of the raw coal are not limited.

  Next, examples of the present invention will be described. The conditions of the examples are one example of conditions adopted to confirm the feasibility and effects of the present invention, and the present invention is limited to this one example of conditions. It is not done. The present invention can adopt various conditions as long as the object of the present invention is achieved without departing from the gist of the present invention.

(Example)
A caking filler having the composition shown in Table 1 was prepared. The caking fillers of symbols A1, B1, C1, C4, D1 are within the composition range defined in the present invention, and symbols A2, A3, B2, B3, C2, C3, D2, D3, H2, H3 This caking filler is outside the above composition range.

  As non-slightly caking coal, non-slightly caking coal A (volatile content 31%, total expansion rate 10%) with low expansibility (total expansion rate) prescribed by JIS and non-slightly viscous content with relatively high volatile content. Carbonized B (volatile content 35%, total expansion rate 21%) was used. Using these non-slightly caking coals, blending coal A with a blending ratio of non-slightly caking coal A 40% (volatile content 26.8%, weighted average value of total expansion rate 52%) or non-slightly caking coal Addition of the caking filler of the composition shown in Table 1 to the blended coal B with a blending ratio of B of 40% (volatile content 28.4%, weighted average value of total expansion coefficient 56%) shown in Table 2 And coke was produced.

  The raw coal was pulverized in advance to 3% under 82%, and charged into a test coke oven at a moisture content of 3%, a charging density of 0.83 dry, and t / m3.

The coke produced was measured for DI ¹⁵⁰ ₁₅ and CSR. The results are also shown in Table 2.

From Table 2, it can be seen that DI ¹⁵⁰ ₁₅ has an extremely high strength of 85 levels in both the comparative example and the inventive example. Further, the CSR of the comparative example is 58 to 60, whereas the CSR of the invention example is 64 to 65, which indicates that the CSR is further improved.

As described above, according to the present invention, a petroleum pitch obtained by separating light oil from petroleum heavy oil is obtained by thermally reforming by a hydrogenation reforming reaction and then separating the resulting light oil. By blending the resulting binder into raw coal, high strength coke with DI ¹⁵⁰ ₁₅ of 84.5 or more and CSR of 60 or more can be produced. In addition, heavy metals such as sulfur and vanadium contained in petroleum heavy oil can be efficiently separated and removed without making new capital investment. As mentioned above, by using petroleum heavy residue as a caking agent for coke production, the industrial value in terms of producing high-strength coke for blast furnaces by effectively utilizing a large amount of petroleum pitch. Is not only large, but also has great social significance in terms of environmental protection.

It is a figure which shows the composition area | region (area | region enclosed with the continuous line) of the caking filler used by this invention.

Claims (7)

  A caking filler to be blended with raw coal to produce high-strength coke, soluble in hexane (HS component): 45-84% by mass, insoluble in hexane and soluble in toluene (HITS component) ): 15 to 54% by mass, and a component insoluble in toluene (TI component): 1 to 40% by mass, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.95 to 1 10. A caking filler excellent in strength enhancement characteristics, characterized by being 10.   A caking filler to be blended with raw coal to produce high-strength coke, soluble in hexane (HS component): less than 45% by weight, insoluble in hexane and soluble in toluene (HITS component) 15 to 99% by mass, and a component insoluble in toluene (TI component): 1 to 85% by mass, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.85 to 1. A caking filler excellent in strength enhancement characteristics characterized by being 10.   The caking filler excellent in strength enhancement characteristics according to claim 1 or 2, wherein the raw coal contains more than 20 mass% of non-slightly caking coal.   In the method for producing high-strength coke by dry distillation of raw coal, components soluble in hexane (HS component) in the raw coal: 45-84% by mass, components insoluble in hexane and soluble in toluene (HITS component) 15 to 54% by mass, and a component insoluble in toluene (TI component): 1 to 40% by mass, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.95 to 1. A method for producing high-strength coke, which comprises blending a caking filler of 10.   In the method for producing high-strength coke by dry distillation of raw coal, a component soluble in hexane (HS component) in the raw coal: less than 45% by mass, a component insoluble in hexane and soluble in toluene (HITS component): 15 to 99% by mass, and a component insoluble in toluene (TI component): 1 to 85% by mass, the remainder is an inevitable residual component, and the H / C atomic ratio is 0.85 to 1.10. A method for producing high-strength coke, characterized in that it contains a caking filler having excellent strength enhancement characteristics.   The method for producing high-strength coke according to claim 4 or 5, wherein the raw coal contains more than 20% by mass of non-slightly caking coal.   The method for producing high-strength coke according to any one of claims 4 to 6, wherein the caking filler is blended in an amount of 0.2 to 5 mass% with respect to the raw coal.

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