WO2005077826A1

WO2005077826A1 - Method for producing amorphous carbon particles

Info

Publication number: WO2005077826A1
Application number: PCT/JP2005/002072
Authority: WO
Inventors: Yoichi Takagi; Yoshinori Isomura; Yoshiyuki Shimo; Takayuki Hirayama
Original assignee: Mitsubishi Corporation; Nippon Oil Corporation
Priority date: 2004-02-12
Filing date: 2005-02-10
Publication date: 2005-08-25
Also published as: JP2007191316A

Abstract

A method for producing amorphous carbon particles characterized by having a non-circular cross section, exhibiting a mass reduction rate after the retention at 500°C for 60 minutes in the presence of air of less than 30 % and having an average particle diameter of 1 to 50 μm, characterized in that the method comprises (1) a step of moistening a combustion ash of a petroleum coke, (2) a step of adding an acidic water, followed by warming and agitation, to thereby extract a metal component in the combustion ash, (3) a step of separating an insoluble carbon component from the metal component dissolved in the acidic water, and (4) a step of drying and pulverizing the carbon component separated in the step (3). The above method allows the economical production of amorphous carbon particles having a high carbon purity, being free from the elution of a metal, being excellent in stiffness and strength, and being markedly reduced in the specific surface area and the pore volume, through the removal of a metal component from a combustion ash of a petroleum coke.

Description

Specification

Manufacturing method of amorphous carbon particles

The present invention relates to a method for producing amorphous carbon particles. More specifically, the present invention relates to a method for producing amorphous carbon particles having excellent properties such as material strength, corrosion resistance, conductivity, heat resistance, and dimensional stability, and also having excellent economic efficiency. Background art

[0002] Amorphous carbon is a heterogeneous carbon material having a homogeneous glassy structure, and has recently been applied to various fields due to its excellent mechanical strength, alkali resistance, acid resistance, and conductivity. Is expected. Conventionally, as a method for producing such amorphous carbon, for example, as disclosed in Patent Documents 13 to 13, a molded article of a thermosetting resin such as phenol resin or furfuryl alcohol resin is fired and carbonized. Amorphous carbon obtained by calcining thermosetting resin in this way not only increases the cost, but also has a sufficient residual carbon ratio during firing. However, the material strength was inferior to the expected value.

[0003] By the way, petroleum coatas is an inexpensive carbon-based fuel having a higher calorific value than coal, and is currently widely used as a fuel in industrial boilers and the like. The combustion ash discharged from such a combustion furnace using petroleum coatas generally contains unburned carbon in a proportion of 70% by mass or more, and has a drying calorie equivalent to that of coal. It is used as fuel in cement firing kilns and as carbon material for reduction in melting furnaces at refineries. However, the unburned carbon content contained in petroleum coatas combustion ash has extremely low activity and reactivity, and the combustion ash contains many impurities other than carbon content. Its evaluation as a fuel or carbon material is low, and it is expected that in the near future it is highly likely that it will be disposed of as landfill, etc. as industrial waste!

[0004] Various techniques have been proposed for effectively utilizing unburned carbon in fuel ash, but the technique is often not applicable to unburned carbon in petroleum coatas combustion ash. For example, in Patent Document 4, pulverized coal boiler ash is mixed with water having a specific gravity of less than 1 and water. A technique is disclosed in which a water-miscible organic solvent is mixed, the mixture is poured into water, carbon in the pulverized coal boiler ash is floated together with the organic solvent, and the float is used as a fuel together with the carbon. However, the unburned carbon content in the petroleum coatas combustion ash separates from the organic solvent and does not sink to the water floor and float.

[0005] Further, in Patent Document 5, fly ash containing carbon is formed together with an oxidizing agent in a combustion gas formed by jetting a fuel and an oxidizing agent into the combustion furnace in a combustion furnace. Spraying to burn the carbon in the fly ash, melt the fly ash, and quench the molten fly ash in a cooling furnace to produce fly ash with low carbon and high vitrification rate. Although disclosed, petroleum-kotas combustion ash has an extremely low silica content, so fly ash cannot be produced.

[0006] These technologies are mainly applicable to the combustion ash of industrial boilers using heavy oil or coal as fuel, and cannot be applied to the combustion ash of industrial boilers using petroleum coatas as fuel. These technologies use carbon contained in the combustion ash that uses heavy oil or coal as fuel, or remove carbon to improve the quality of fly ash. Focusing on the peculiarity of the carbon content in the combustion ash from industrial boilers using Kotus as a fuel, it was not a technology that could be used as a value-added product.

[0007] As described above, no method has been hitherto attempted to utilize the carbon content of the combustion ash of petroleum coatas as a valuable resource.

Patent Document 1: Japanese Patent Publication No. 39-20061

Patent Document 2: Japanese Patent Publication No. 63-59963

Patent Document 3: Japanese Unexamined Patent Publication No. 3-164416

Patent document 4: Japanese Patent Application Laid-Open No. 7-213949

Patent Document 5: Japanese Patent Application Laid-Open No. 10-281438

Disclosure of the invention

Problems to be solved by the invention

[0008] Accordingly, the present invention provides a method for removing amorphous carbon particles from petroleum coatas, which removes metal components, has high carbon purity, has no metal elution, has excellent rigidity and strength, and has an extremely small specific surface area and pore volume. It is an object to provide a manufacturing method. Means for solving the problem

[0009] The present invention for solving the above-mentioned problems includes (1) a step of humidifying the combustion ash of petroleum coatas, and (2) a step of adding an acid water and extracting a metal component in the combustion ash by heating and stirring. (3) a step of separating the metal dissolved in the acidic water in the step (2) from the insoluble carbon, and (4) drying the carbon separated in the step (3). * It has a non-circular cross section, characterized by having a pulverizing step, has a mass loss rate of less than 30% for 60 minutes at a holding temperature of 500 ° C in the presence of air, and has an average particle diameter of 1 to 50 m. A method for producing amorphous carbon particles.

[0010] The present invention also shows a method for producing amorphous carbon particles, wherein a reducing agent is added together with acidic water in the metal extraction step (2).

[0011] The present invention further provides a method for producing amorphous carbon particles, wherein in the metal extraction step (2), the reducing agent is a sulfite solution, hydrazine or sodium sulfite.

[0012] In the present invention, further, in the metal extraction step (2), acidic water having a pH of 1 to 3.0 is added in a ratio of 2 to 10 times the mass of the combustion ash, and the liquid temperature is 40 ° C or more, and the stirring time is It shows a method for producing amorphous carbon particles, characterized in that the treatment is performed within 90 minutes.

[0013] The present invention also can be obtained amorphous carbon particles, specific surface area measured by BET method 20- lm ² Zg, pore volume measured by the nitrogen adsorption method 0. 020-0. OOlml / g This shows a method for producing amorphous carbon particles.

[0014] The present invention further provides a method for producing amorphous carbon particles in which the obtained amorphous carbon particles have a plane spacing of 3.43A or more as measured by X-ray diffraction.

The invention's effect

[0015] According to the present invention, the combustion ash power of petroleum coatas removes metal components, increases carbon purity, does not elute metals, has excellent rigidity and strength, and has extremely small specific surface area and pore volume. Can be provided economically.

Brief Description of Drawings

FIG. 1 is a diagram schematically showing a configuration of a manufacturing apparatus used in a manufacturing method according to the present invention. Plane.

FIG. 2 is an electron micrograph (a photograph substituted for a drawing) at a magnification of 20000 times showing the particle shape of amorphous carbon obtained by the production method according to the present invention.

Explanation of symbols

The symbols used in FIG. 1 indicate the following, respectively.

1: Combustion ash, 2: Transport device, 3: Water spray device, 4: Stirring tank, 5: Sulfuric acid, 6: Water, 7: Reducing agent, 8: Belt filter, 9: Shower washing device, 10: Drying device , 11: crusher, 12: recovery tank, 13: filtrate treatment tank, 14: filtration device.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail based on embodiments.

In the process of examining the effective use of unburned carbon in petroleum knots combustion ash, the present inventors pickled ash (metal oxide) from combustion ash, solid-liquid separated carbon, dried, The carbon obtained by pulverization and sizing is amorphous, that is, amorphous, and has excellent rigidity, strength, heat resistance, and extremely small specific surface area and pore volume. Non-circular cross-section with sharp edges, showing a complex shape with sharp protrusions and smooth curved surfaces on the particle surface.It can be used alone or with an organic substance such as rubber or rubber, or cement. The present inventors have found that excellent performance can be exhibited by incorporating the compound in a matrix of an inorganic substance such as metal and glass, and the present invention has been accomplished.

FIG. 1 is a drawing schematically showing one embodiment of a production apparatus used in one embodiment of the method for producing amorphous carbon particles according to the present invention.

[0020] In the manufacturing apparatus shown in Fig. 1, for example, combustion ash 1 collected and collected by a dust collector in a boiler using petroleum coatas as fuel is used as a raw material.

[0021] As is well known, petroleum coatas mainly heats heavy residual oil (asphalt component) coming from a vacuum distillation unit to 500 ° C-600 ° C during the process of refining crude oil. It is a carbon product that is produced as a solid by separating caustic reaction, pyrolysis, and volatile gasoline, kerosene, and gas oil fractions.

[0022] There are differences in properties depending on the place of production and the production process of crude oil, and there is no particular limitation. However, the properties of petroleum coatas include, for example, total moisture 4.8%, ash 0.3-0.6%, volatile content 10-14%, calorific value 8000-9000kcalZkg, sulfur content 0.5-6. %, Nonadium content 300 to 2500 ppm. As petroleum coatas, those having relatively high vanadium and nickel contents are suitable.

[0023] The combustion ash as a raw material is recovered from a combustion furnace using such petroleum coatas as a fuel, for example, a pulverized coal boiler, a gasifier, and the like. Although it is not particularly limited, for example, the temperature may be 800-1300 ° C. in an oxidizing atmosphere!

[0024] The composition of the combustion ash serving as a raw material is not particularly limited.

2

0.1-1% by mass, C 72-90% by mass, H 0.1-1.5% by mass, 0.1-1% by mass, C1 0.01-1.1% by mass, NH1-3% by mass , SO 3-20% by mass, V 0.50-2.

3 4

50 mass ^{_{0/0, Fe 0. 10-1.}} 00 mass ^{_{0/0, Mg 0. 02-0.}} 10 mass ^{_{0/0, P 0. 01-0.}} 10 mass ^_0/0, Ca 0. 05- 0.25 mass ^{_{0/0, Na 0. 05-0.}} 25 mass ^{_{0/0, K 0. 01-0.}} 05 mass ^{_{0/0, A1 0. 05-0.}} 30 mass ^_0/0, Si ^0. For example, a composition such as 02-0.80%, Ni 3500-6500 mg / Kg, and Mo 50-100 mg ZKg can be exemplified. For reference, if one typical composition is shown, HO 0.5% by mass, C 78.9% by mass, H 0.8

2

Mass%, O 7.14 mass%, C1 0.04 mass%, NH 2.45 mass%, SO 16.10 quality

3 4 weight%, ¥ 1. 00 wt%, Fe 0. 23 mass%, Mg 0. 07 wt%, P 0. 04 mass%, Ca 0. 21 wt ^_0/0, Na 0. 10 mass ^_0/0 , K 0. 03 mass ^_0/0, A1 0. 24 mass ^{_{0/0, Si 0. 78%}} , Ni 4600mg / Kg, there is the power of Mo 90mg / Kg and!ヽUmo.

As shown in FIG. 1, the combustion ash 1 collected from such a combustion furnace is first conveyed to a stirring tank 4 using a conveying device 2 such as a belt conveyor. A water spray device 3 is installed on the transport device 2 and sprays water on the transported combustion ash 1 to perform humidification.

[0026] In the present invention, the humidification treatment facilitates the elution of the metal component in the metal extraction step as described later, and a high yield can be obtained in a short time.

As a humidifying method, for example, a water spray method as shown in FIG. 1, water spraying, or other general humidifying methods can be used, but a water spray method is preferable. The According to the water spray method, the combustion ash can be uniformly humidified only by spraying water in the form of mist, and can be treated very easily.

[0028] The humidification treatment is not particularly limited, but is desirably performed by adding water in a ratio of 10 to 30% by mass to the combustion ash to be treated. . When the humidification treatment is performed using such a ratio of water, dust is not substantially generated when the combustion ash is transferred or loaded, and the handling of the combustion ash is facilitated. If the amount of water added is extremely increased beyond the range described above, the humidified combustion ash may be liquified, and on the other hand, as described above, the amount of water added is extremely small. The intended effect of such humidification may be reduced. Further, the combustion ash that has been subjected to the humidification treatment may be kept in a humidified state for about one day in order to improve the extraction rate of the metal in the metal extraction treatment step described below.

[0029] Next, the combustion ash 1 is charged into the agitation treatment tank 4, and the combustion ash is added with acidic water prepared with sulfuric acid 5 and water 6 and, if necessary, a reducing agent 7, and heated. 'Extract metals in combustion ash by stirring.

As the acid of the acidic water used in the present invention, in addition to the sulfuric acid shown in FIG. 1, an acid capable of using hydrochloric acid, nitric acid or the like or a mixture thereof is preferably used. And most preferably sulfuric acid. Here, if the acidic water is not added, the extraction rate of the metal component in the metal extraction treatment step decreases, which is not preferable.

[0031] Further, the pH of the acidic water is not particularly limited, but, for example, is preferably pH 0.11 to 3.0, more preferably pH 5.0 to 1.0. If the pH is less than 1, there is a risk that a large amount of acidic water will be used for the treatment, while if the pH exceeds 3.0, the extraction efficiency for vanadium may decrease. is there.

[0032] The amount of the acidic water to be added is not particularly limited, but is, for example, an amount that is 2 to 10 times the amount of the combustion ash (dry mass) to be treated. If the amount of the acidic water is less than twice, there is a possibility that a sufficient dissolution treatment of the soluble component cannot be performed. On the other hand, if the addition amount exceeds 10 times, not only is it not economical, but also the labor required for the waste liquid treatment after the solid-liquid separation treatment described later may increase.

[0033] The reducing agent 7 added as necessary together with the acidic water is not particularly limited. However, for example, sulfurous acid, hydrazine, sodium sulfite, hydroxylamine and the like can be used. Sulfurous acid, hydrazine or sodium sulfite, which is excellent in reducing action, is more preferably sulfurous acid.

[0034] Such a reducing agent 7 is added to the combustion ash almost at the same time as the above-mentioned acidic water and before heating. The amount of the reducing agent to be added is not particularly limited. For example, 0.02 to 1.0 part by mass, preferably 0.1 to 1.0 part by mass of the reducing agent per 100 parts by mass of the combustion ash (dry mass). It is desirable to add 1-0.6 parts by mass. If the amount of the reducing agent is less than 0.02 parts by mass, the reduction reaction may not be sufficiently performed, while if the amount exceeds 1.0 parts by mass, the remaining reducing agent is treated. This is because the necessity arises and the operation of the process may be complicated.

[0035] In the stirring treatment tank 4, the combustion ash and the mixed slurry of the acidic water and the reducing agent are mixed at a temperature of, for example, 40 ° C or more, more preferably 50 to 80 ° C. The mixture is heated and stirred at a predetermined rotation speed to sufficiently dissolve the acid-soluble metals in the combustion ash. Here, the reason why the heating temperature is set to 40 ° C or higher is that at a temperature lower than 40 ° C, the extraction rate decreases.

[0036] The stirring method is not particularly limited, and for example, a general method such as stirring using four impeller one-incline blades can be used. The stirring conditions are appropriately changed depending on the concentration of the acidic water in the extract, the solution temperature, and the like. For example, when a sulfuric acid aqueous solution of pHO.6 is added to the combustion ash in a double amount by mass ratio to the combustion ash, and the solution temperature is 60 ° C, a stirring treatment for about 90 minutes is appropriate.

[0037] By the metal extraction treatment to which the acidic water and the reducing agent are added as described above, the metal components such as V, Al, Fe, Mg, Mo, and Ni contained in the combustion ash are dissolved in water. However, on the other hand, the carbon remains insoluble as a solid.

After a lapse of a predetermined time, the mixed slurry taken out from 4 parts of the stirring treatment tank is subjected to solid-liquid separation by a solid-liquid separation device.

[0039] Examples of the solid-liquid separation device used in the present invention include, but are not limited to, a pressure filter, a centrifuge, a decanter, a belt filter, a tray filter, a precoat filter, a ceramic filter, and a cricket. Various known filters such as a filter and a press roll filter can be used. Figure 1 shows a solid-liquid separation device. The use of the belt filter 8 is exemplified.

In FIG. 1, when the solid-liquid separation was performed by the belt filter 8, only the carbon insoluble in the acidic water substantially remained on the filter, while the carbon dissolved in the acidic water. The filtrate containing a metal component such as vanadium is collected from the bottom of the solid-liquid separator 8 into the collection tank 12.

[0041] The wet carbon content remaining on the belt filter 8 due to the solid-liquid separation is conveyed as it is by a conveyor, and is heated in a shower washing device 9 at a temperature of, for example, about 20 to 80 ° C, preferably about 60 ° C. Washed thoroughly. The washing method is not particularly limited as long as the attached acidic water can be sufficiently removed, and various devices can be used. The water used for washing is collected as a washing filtrate, and the collected washing water may be reused as an acidic extraction water, if necessary.

[0042] The washed wet carbon component is then conveyed to the drying device 10 and subjected to a drying step. The drying step is not particularly limited, but may be air drying at a temperature of 100 to 200 ° C., oven drying, natural drying, or the like. Utilizing the fact that the amorphous carbon according to the present invention has conductivity, a drying method by energization may be considered. As a drying method, it is desirable to use a heat transfer heating type drying method from the viewpoints of dust prevention and combustion prevention. In any case, since the amorphous carbon according to the present invention has an extremely small specific surface area and a small pore volume and is excellent in heat conductivity, it can be dried very efficiently. By such a drying step, for example, a wet carbon content having a water content of about 30 to 40% by mass is converted into a dry carbon content having a water content of less than 1.0% by mass.

Next, the dried carbon component removed from the drying device 10 is then conveyed to a crushing device 11, where it is crushed to a predetermined particle size, for example, an average particle size of less than 10 m. The pulverizing step is not particularly limited, but is performed by performing a pulverizing treatment using a physical pulverizer such as a turbo mill, a ball mill, a jet mill, a roller mill or the like. It is preferable to use a jet mill as the pulverizing device because the carbon component to be pulverized has a high hardness and is already in the form of fine powder.

[0044] In the production method of the present invention, if necessary, a classification treatment may be performed after the pulverization treatment. Can do.

Further, in the manufacturing apparatus shown in FIG. 1, the filtrate collected in the collection tank 12 in the solid-liquid separation process is then pressure-fed to the filtrate treatment tank 13. In the filtrate treatment tank 13, a pH adjuster such as ammonia or caustic soda is added to the filtrate to adjust the pH of the filtrate to 417. Thereby, an oxidizing metal component such as vanadium is precipitated. Thereafter, the filtrate containing the precipitate is subjected to solid-liquid separation by the filtration device 14, whereby the vanadium recovery cake and the nickel-containing filtrate can be separated. Examples of uses of the separated metal include an electrolyte for a redox flow battery, a material for stainless steel, and the like. Furthermore, by adjusting the pH, it can be recovered as a cake containing both vanadium and nickel.

As shown in FIG. 2, the carbon particles obtained by the production method according to the present invention have a non-circular cross section having sharp edges that are not flake-like like graphite or spherical like carbon black. It has a complicated shape with sharp projections and smooth curved surfaces on the particle surface. The crystal structure measured by the X-ray diffraction method indicates that the amorphous carbon particles exhibit an amorphous structure and an L-layer structure (as is clear from the fact that the interplanar spacing is 3.43 A or more). In addition, the mass loss rate in the presence of air at a holding temperature of 500 ° C for 60 minutes is less than 30%, and the reactivity to air is very poor. Further, the average particle size is 1-150 m, more preferably 110-10 m. The shape of the non-circular cross-section having such sharp edges may be, for example, an anchoring effect with the matrix material at the time of compounding with a matrix material such as resin, rubber, cement, metal, or the like, A spike effect can be expected.

[0047] The amorphous carbon particles obtained by the production method according to the present invention have a specific surface area of 1-120 m ² Zg measured by the BET method and a pore volume of 0.020-g measured by the nitrogen adsorption method. 0. It is about OOlmlZg and has relatively dense surface properties. Further, although not particularly limited, typical other characteristics include a bulk specific gravity measured by a manual filling method of 0.5-0.7 g / mU a true specific gravity measured in accordance with JISK21515.3. Is 1.9—2.1.

[0048] The amorphous carbon particles obtained by the production method according to the present invention can be used, for example, as they are. For example, it can be used as various catalyst carriers, fluidized bed media and the like. In addition, the amorphous carbon particles according to the present invention have an affinity for the displacement of the oil-based base material and the aqueous base material, and therefore, impart conductivity, improve rigidity and mechanical strength, improve dimensional stability, and improve heat resistance. For the purpose of improvement and the like, it can be blended with a matrix material composed of various resins and organic substances such as rubber or inorganic substances such as cement and metal. Specifically, for example, a resin or rubber molding material, a coloring agent such as a light-shielding fiber, a resin or rubber modifier or filler, a resin or rubber conductivity imparting agent, for example, an antistatic material , Resistance materials in copiers,

It can be preferably used in various applications such as an electric resistance adjusting material for a sheet heating element utilizing PTC characteristics, artificial marble, and the like.

[0049] In addition, application to various liquid compositions such as lubricants, traction drive fluids, electrorheological fluids, non-linear optical materials, various inks, and coloring compositions such as paints can be considered. .

[0050] Further, in various applications such as a coloring agent, a filler, an aggregate, etc., it can be preferably blended with a matrix material composed of an inorganic substance such as a cement composition, a metal, or glass. Example

Hereinafter, the present invention will be described more specifically based on examples.

Example 1: Preparation of amorphous carbon particles

After burning petroleum coke in a pulverized coal boiler (combustion condition: burning at 800-1300 ° C in an oxidizing atmosphere), the combustion ash collected by a dust collector was recovered.

[0053] Analysis of the composition of this combustion ash showed that the water content was 0.4% by mass, the carbon content was 86.3% by mass, and the hydrogen content was hydrogen.

0.21 mass ^_0/0, oxygen 1.23 wt ^{_{0/0, NH 1. 63%}} , SO 4. 10 mass ^_0/0, V 1. 25

3 4

Mass ^_0/0, Ni 0. 58 mass ^_0/0, Fe 0. 56 mass ^_0/0, Mg 0. 06 mass ^_0/0, Ca 0. 25 wt%, Na 0. 16 mass%, A1 0. 24 A component result of mass% and Si of 0.69% was obtained.

[0054] After 100 parts by mass of the combustion ash was humidified by using a production apparatus as shown in Fig. 1, 200 parts by mass of acidic water (5% sulfuric acid aqueous solution) was added in a stirring treatment tank, and further reduced. Add 0.6 parts by mass of an aqueous solution (sulfurous acid aqueous solution), stir for 1 hour while maintaining the pH at 0.6 and heating to 60 ° C. The carbon content is separated into solid and liquid by a belt filter, washed with water, dried in an oven at 150 ° C, and then jetted. By pulverizing with a mill and classifying, carbon particles were obtained with a yield of 75%.

When the particle size of the carbon particles thus obtained was examined by a laser diffraction method, the average particle size was 4.2 m, the standard deviation was 0.183, and the average particle size was 0.75 μm. Particles below and above 20.0 m were not detected.

The obtained carbon particles were examined for various physical properties. The specific surface area measured by the BET method was 10.8 m ² Zg, the pore volume measured by the nitrogen adsorption method was 0.013 mlZg, and the The bulk density measured by the filling method was 0.559 g / mU, and the true specific gravity measured according to JISK21515.3 was 2.05.

Next, when the crystal structure of the carbon particles was measured by an X-ray diffraction method, the plane distance d (the distance between two adjacent lattice planes) was 3.4587 A, and the crystallite size Lc was 3.12 A. And an amorphous structure (L layer structure)!

[0058] Further, in order to investigate the reactivity of the carbon particles with air, the holding temperature in the presence of air was measured.

The mass loss rate at 60 minutes at 500 ° C was measured with a differential thermobalance (TGD3000 manufactured by Vacuum Riko) (measurement conditions: 20 mg of sample, 20 ml of air flow, 20 min of heating rate 20 ° CZ). It was 9%, indicating that it was very unreactive. Further, when the amount of impurities contained in the obtained carbon emissions particles was measured by plasma ion source analyzer (ICP analyzer), V (vanadium) is 0.19 mass ^_0/0, Ni (nickel) is 0. 04 mass ^_0/0, I be less impurities carbon particles were obtained by high extraction effect ChikaraTsuta.

FIG. 2 shows an electron micrograph of the obtained carbon particles.

[0060] Comparative Example 1

As a comparison, the mass loss rate of the coal coatas at 500 ° C for 60 minutes was examined under the same conditions as in Example 1 and found to be 60.0%, clearly having different characteristics.

[0061] Comparative Example 2

The same operation as in Example 1 was carried out on the same petroleum coatas combustion ash as used in Example 1 except that the pulverizing step was not performed after the oven drying treatment, to obtain carbon particles. The particle size of the obtained carbon was 61.2 m, which was large. [0062] Comparative Examples 3 and 4

Except for the operations in the following table, the same operations as in Example 1 were performed to obtain petroleum coatas combustion ash carbon particles. As shown in the table below, the obtained carbon particles were found to have a higher impurity metal content as compared with Example 1.

[Table 1] Example] Comparative Example 3 Comparative Example 4

Condition Humidification process: Yes / No Yes No Yes

Acidic water: used / unused used used unused

Result V mass% 0.0.62 0.1

Ni mass% 0.04 0.32 0.34 1

Claims

The scope of the claims

[1] (1) a step of humidifying the combustion ash of petroleum coatas,

(2) a step of adding acidic water and extracting metal components in the combustion ash by heating 'stirring,

(3) a step of separating the metal component dissolved in the acidic water from the insoluble carbon component in the step (2);

(4) a step of drying and pulverizing the carbon component separated in the step (3).

An amorphous carbon particle having a non-circular cross section, a mass loss rate of less than 30% for 60 minutes at a holding temperature of 500 ° C in the presence of air, and an average particle diameter of 1-150 μm. Production method.

2. The method for producing amorphous carbon particles according to claim 1, wherein in the metal extraction step (2), a reducing agent is added together with the acidic water.

3. The method for producing amorphous carbon particles according to claim 2, wherein in the metal extraction step (2), the reducing agent is a sulfite solution, hydrazine or sodium sulfite.

[4] In the metal extraction step (2), acid water of pHO.

The method for producing amorphous carbon particles according to any one of claims 13 to 13, wherein the processing is performed by adding 0 times, and treating the mixture at a liquid temperature of 40 ° C or more and a stirring time of 90 minutes or less.

[5] The obtained amorphous carbon particles have a specific surface area measured by a BET method of 20-lm ² and a pore volume measured by a nitrogen adsorption method of 0.002-0.001 ml / g. The method for producing amorphous carbon particles according to any one of Items 1-4.

[6] The method for producing amorphous carbon particles according to any one of [15] to [15], wherein the obtained amorphous carbon particles have a plane distance measured by X-ray diffraction of 3.43A or more.