AU649915B2

AU649915B2 - Process for granulating coal powder

Info

Publication number: AU649915B2
Application number: AU33876/93A
Authority: AU
Inventors: Hiroaki Kuroki; Katsumi Tomura; Takeshi Yoshida
Original assignee: Idemitsu Kosan Co Ltd
Current assignee: Idemitsu Kosan Co Ltd
Priority date: 1992-03-13
Filing date: 1993-03-01
Publication date: 1994-06-02
Anticipated expiration: 2013-03-01
Also published as: DE4307926A1; JP2731484B2; JPH05255676A; DE4307926C2; AU3387693A

Description

1-1 1

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): Idemltsu Kosan Co., Ltd.

ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: Process for granulating coal powder The following statement is a full description of this invention, including the best method of performing it known to me/us:- 0 0 a BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a process for granulating coal powder, specifically to an efficient and practically advantageous process for granulating various coal powders, including fine powders of coals, such as peats, brown coals, sub-bituminous coals, bituminous coals, .semianthracite coals and anthracite coals, fine powders of various carbonaceous materials derived from the coals, such as cokes, chars, active carbons and carbon blacks, and fine 15 powders of various carbonaceous materials similar to these coal carbonaceous materials, such as petroleum cokes, petroleum active carbons and petroleum carbon blacks, into spherical granules which have such a fairly uniform particle size, high density and excellent mechanical 20 strength as to withstand transportation. The granulation product may be used as a finished product or as an intermediate product.

For example, the granules obtained by the process of the present invention are useful in various utilization fields of granular carbon materials, for example, as the 1 raw materials of granular active carbon, which is useful as a catalyst support or absorbent, or as a reducing carbon medium or filter medium or the raw materials thereof.

Description of the Related Art There are various known methods of granulating fine powder of coals into spherical granules of a desired size. Every conventional method, however, involves problems in that it is industrially disadvantageous due to its complement granulating procedures and steps, or the resulting granules are insufficient in density, mechanical strength or the uniformity of particle size. There have "been, therefore, a strong demand for solving these problems by developing industrial granulating methods which enable 15 efficient production of spherical granules applicable to wide uses.

Typical examples of the conventional granulating techniques Include a wet-granulation of powdered coal, which is a typical example of oil-agglomeration methods for 20 producing spherical granules by dropping a surfactant or hydrocarbon oil as a binder into a water slurry of coal fines with stirring [Japanese Patent Application Kokai Koho (laid-open) No. 56-141391], and a method wherein a fine powder of a coal is granulated with an (incline) disk-type pelletizer by using a binder, such as CMC or PVA ("studv of 3 1 the technique for producing spherical active carbon from coals": Report by Environmental Pollution Resource Institution, No. 11, 1979). These methods also involve the same problems.

The oil-agglomeration method (the wetgranulation of powdered coal) is an excellent method of separating lipophilic carbonaceous matters in the starting coal powder from water while removing hydrophilic ash from coal granules, but the obtained granules have low density and are too inferior in mechanical strength to withstand transportation.

the spherical granulation method using an (incline) disk-type pelletizer, binder, such as water or an aqueous PVA sclution, is sprayed into the granulator 15 [(incline) disk-type pelletizer] in which a coal powder is being agitated, to form granulation cores and to grow spherical granules around the granulation cores. In this method, however, a fine mist of the binder has to be sprayed uniformly all over the disk of the granulator to 20 obtain granules of a uniform particle size. Further, this method requires very difficult procedures and adjustment for obtaining granules of a uniform particle size efficiently and stably since the range of the applicable viscosity of the binder is very narrow. For example, binders of low density cause difficulty in granulation or 1 decrease considerably the granulation efficiency, and binders of high density cause difficulty in producing uniform granules. Even the granules endowed with a uniform particle size have low density and insufficient mechanical strength.

SUMMARY OF THE INVENTION The present invention was made in consideration of the above-described problems, and an object of the present invention is to provide a simple and efficient process for granulating fine powder of various coals (carbonaceous materials) stably into spherical granules 15 having sufficiently high density, sufficiently high mechanical strength and a uniform particle size.

Another object of the present invention is to provide a process for granulating coal powder wherein after the production of granules, the granules are treated to 20 further improve their characteristics and properties, such as mechanical strength, thereby providing granules which .:.ooi have excellent performances and are applicable for wider uses, for example, as raw materials of active carbons.

As a result of repeated research, the inventors found that spherical granules having high density, high mechanical strength and a uniform particle size could be obtained efficiently by a simple procedure wherein a coal powder having an average particle size and maximum pirticle size not larger than specific values, respectively, and containing particles larger than a specific particle size in a ratio not more than a specific value is used as a raw material, and the coal powder is granulated by using a specific granulator, namely a high speed agitated granulator, and a thermal cracking residue as a binder or a binder component. They also found that an oxidation treatment, specifically an oxidation treatment with an oxygen-containing gas at relatively low temperatures, could further improve the mechanical strength of the granules, thereby providing granules of high performances which are applicable for wider uses, for example, as a raw material of active carbon. On the basis of these findings, the inventors have completed the present invention.

According to the present invention there is provided a process for granulating a coal powder, comprising granulating 20 a coal powder in the presence of a thermal cracking residue or catalytic cracking residue as a binder by using a high *o I speed agitated granulator, the coal powder having an average particle size of not more than 30 pm and a maximum particle size of not more than 100 pm, and 'not more than 10% by weight 25 of the coal powder having a particle size of not less than 74 pm and the thermal cracking residue or catalytic cracking residue having a viscosity of not more than 1,000 cst.

9 3o 0 .0 "kI 'IAY rlol< 940323,p:\oper\dab,33876.spe,5 6 1 The present invention further provides, as a particularly suitable modification of the process of the present invention, a process for endowing the resulting granules with further improved properties, such as mechanical strength, by subjecting the granules to an oxidation treatment at a temperature ranging from 50 to 150 PREFERRED EMBODIMENTS OF THE INVENTION The coal powder to be used as the raw material or S. a component thereof in the process of the present invention may be pulverized powder of various kinds and compositions 1.5 of coals, that is a wide variety of coal powders including fine powders of all kinds of coals, such as peats, brown coals, lignites, sub-bituminous coals, bituminous coals, semianthracite coals and anthracite coals, fine powders of various coal carbonaceous materials derived from these •o 20 coals, such as cokes, chars, active carbons and carbon blacks, and fine powders of various other carbonaceous materials similar to these coal carbonaceous materials, such as petroleum cokes and petroleum carbon blacks. Among these various coal powders, fine powders of the abovedescribed various coals and/or the above-described various 1 coal carbonaceous materials, especially, fine powders of the above-described various coals are generally suitable.

Among the above-described various coals, preferred are subbituminous coals, bituminous coals, semianthracite coals and anthracite coals. The use of a fine powder of a subbituminous coal, a bituminous coal, a semianthracite coal or an anthracite coal makes it easier to obtain granulates which have excellent properties suitable for the production of active carbon.

The coal powder may consist of a fine powder of one kind of coal or may consist of a fine powder mixture of

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two or more coals. Fine powders which were recovered from the process of the present invention, for example, by sieving or cracking, may be recycled and be mixed into the 15 starting coal powder.

In the process of present invention, it is important that the coal powder to be granulated with the e high speed agitated granulator has an average particle size of not more than 30 g m and a maximum particle size of not 20 more than 100 g m, and that not more than 10 by weight of the coal powder has a particle size of not less than 74 j m. If the coal powder has an average particle size of more than 30 g m or a maximum particle size of more than 100 g m, or if more than 10 by weight of the coal powder has a particle size of not less than 74 g m, it will be 1 difficult to obtain spherical granules of a uniform particle size, or the density or mechanical strength of the granules will be insufficient, and the object of the present invention cannot be accomplished.

In general, the lowest limit of the preferred average particle size is about 10 g m, and coal powders having too small average particle sizes may require a longterm granulation or may be difficult to granulate.

In the process of the present invention, the coal powder, which is the raw material to be granulated and is characterized in particle size as described above, is fed into and granulated in a granulator of a specific type, namely a high speed agitated granulator, and it is another important point that the granulation is carried out in the 15 presence of a thermal cracking residue. Hydrocarbon oils of various compositions and properties, which are obtained from various thermal cracking processes including catalytic cracking processes, may be used as the thermal cracking residue, and preferred examples are hydrocarbon oils S 20 obtained from the thermal cracking processes of petroleums.

Among the petroleum thermal cracking residues, preferred examples include petroleum thermal cracking residues, preferably naphtha cracking residues, more preferably ethylene bottom oils [carbon black oils (CB0)], petroleum fluid catalytic cracking residues, such as FCC 9 1 residues and RFCC residues, a.n -tstyrene bottom oil. These thermal cracking residues function as particularly effective binders for the granulation of the coal powder because of their viscosity higher than the conventional water-soluble binders and their miscibility with the abovedescribed coals and carbonaceous materials. These thermal cracking residues, therefore, further facilitates smooth production of spherical granules having high density, high mechanical strength and a uniform particle size. Further, these thermal cracking residues are also advantageous in that these residues fuse the particles of the coal powder together at the time of carbonizing the obtained granules, 'thereby providing products having extremely high mechanical strength. Such residues, therefore, are particularly 0 effective in the production of coal granules to be carbonized at high temperatures to form active carbons or the like. The thermal cracking residue to be used in the present invention preferably has a viscosity of not more than 1,000 cst, more preferably 15 to 100 cst. Thermal 20 cracking residues having a viscosity of higher than 1,000 cst may cause a difficulty in smooth granulation or a difficulty in the control of the particle size of the granules. Thermal cracking residues having too low viscosities cannot function as effective binders and may make the granulation difficult.

1 The amount of the thermal cracking residue to be used as the granulation binder depends on the kind and composition of the coal powder (for example, the kind of the coal powder and, as to a coal powder mixture, the mixing ratio of each coal powder) and cannot be defined uniformly. Generally, it is desirable to use 10 to 60 by weight of the thermal cracking residue based on the total weight of the coal powder to be granulated.

Another important point of the present invention is the use of a granulator of a specific typ namely a high speed agitated granulator. The high speed agitated granulator is also called a mixed and agitated granulator, and an granulator on the market, such as a Henschel agitated granulator, may be used.

The granulation using the high speed agitated granulator is generally carried out by feeding the coal powder into the granulator wherein the coal powder is agitated, adding thereto the thermal cracking residue as a binder generally with agitation, and then further agitating 20 until granules are formed. The revolution and time suitable for the agitation at the time of granulation 9 cannot be defined uniformly since they depend on the kinds and properties of the coal powder and thermal cracking residue used and on the objective particle size of the granules. In general, a preferred revolution ranges from 1 200 to 1,000 rpm, and a preferred granulation time ranges from 1 to 10 minutes. The particle size of the granules may be adjusted to a desired value by controlling (finely) the revolution and the granulation time. Thus, the coal powder can be granulated into spherical granules having a uniform particle size, which can be adjusted approximately to 0.5 to 10 mm.

Since the granulation using the high speed agitated granulator enables uniform application of a sufficiently high shear to the granules being granulated, granules having high strength and a uniform particle size can be obtained easily. On the other hand, since (incline) disk-type pelletizers cannot apply sufficient shear to the granulates being granulated, the resulting granules have 15 insufficient strength and cannot be adjusted easily to a uniform particle size.

According to demand, the granules granulated by using a high speed agitated granulator as described above may be subjected to various after-treatments common in the art to obtain desired granules.

For example, thus produced granules may be classified to obtain a finished product or an intermediate product of a desired particle size. Granules which have grown excessively may be cracked and then be sieved, or may be mixed into a starting coal powder, which is to be 1 granulated in the same manner as described above, as a recycled material, together with granules smaller than the desired product.

The thus obtained granules, which exhibit sufficiently high mechanical strength as they are, can be further improved in the mechanical strength by subjecting them to an oxidation treatment at low temperatures.

In general, the low-temperature oxidation treatment is carried out preferably at a temperature of to 150 "C It is desirable to carry out the oxidation treatment with an oxygen-containing gas having an oxygen concentration of 1 to 21 by volume. An oxidation treatment at a temperature lower than 50 "C cannot increase the mechanical strength of the granules sufficiently. An 15 oxidation treatment at a temperature higher than 150 °C may cause troubles, such as exothermic or inflammation. An oxidation treatment with a gas having an oxygen concentration higher than 21 by volume may cause :0 .0 troubles, such as exothermic or inflammation. The oxygencontaining gas which may be used include various ones, and some examples are air and gas mixtures of air and inert gasec, such as nitrogen. A preferred oxygen concentration in the oxygen-containing gas ranges from 3 to 21 by volume.

The oxidation treatment at low temperatures 13 1 further increases the strength of the granules, and granules having extremely high mechanical strength can be obtained easily. It should be noted that the thermal cracking residue, which is a cracking hydrocarbon binder being easy to oxidize, used as the granulation binder enables the further effective improvement in strength by the low-temperature oxidation treatment. The lowtemperature oxidation treatment causes the effective oxidation polymerization of the specific binder, whereby the fine particles of th- coal powder fuse together strongly to form granules having extremely high strength.

According to the process of the present invention, as described above, various coal powders can be granulated easily and efficiently into granules having 15 excellent properties, such as high density, high mechanical strength and a good uniformity in particle size.

Because of the above-described excellent properties, the granules obtained by the process of the present invention are useful, for example, as a raw 20 material for the production of granular active carbons, which are useful as catalyst supports or absorbents, and further as a reducing carbon material, as a filter medium or as a raw material thereof, and are suitably applicable in various application fields of granular carbon materials.

In particular, those subjected to the oxidation treatment 14 1 have such an improved strength that they can be used advantageously in the application fields requiring particularly high mechanical strength.

EXAMPLES 1 TO 8 AND COMPARATIVE EXAMPLES 1 TO 3 EXAMPLE 1 As a starting coal powder, 30 kg of a powdered bituminous coal was fed into a high speed agitated granulator (a Henschel agitated granulator). The powdered bituminous coal had an average particle size of 30 g m and a maximum particle size of 95 g m and contained particles *I \of 74 g m or more in particle size in a ratio of 8 by 15 weight based on the total particles. The agitating blades of the granulator were then rotated at 400 rpm. 15 kg of a o. naphtha cracking residue (ethylene bottom oil, namely a carbon black oil: viscosity 56 cst) was dropped into the granulator to perform granulation with agitation. Four minutes after the beginning of the granulation, since the starting powder of bituminous coal disappeared and granules with surfaces covered with the binder were observed, 2 kg of the same powdered bituminous coal was added to dust the binder covering the granules so that the granules became easy to handle, and thereafter the granules were discharged 1 and collected from the granulator.

Subsequently, the granules were sieved with Tyler standard sieves of 6 mesh (sieve opening: 3.327 mm) and 9 mesh (sieve opening: 1.921 mm), to obtain a granulation product of 6 to 9 mesh in particle size. The yield of the granulation product was 53 by weight as shown in Table 1.

In every example, the yield of the granulation product listed in Table 1 is the value of the by weight of the granulation product of 6 to 9 mesh in particle size, which were obtained by sieving as described above, based on the total of the total weight of the coal powder used as the starting material (in Example 1, the weight of the total of the powdered bituminous coal fed) and the weight of the binder used (in Example 1i, the weight of the naphtha cracking residue used).

The hardness and apparent density of the obtained ro.. granulation product of 6 to 9 mesh in particle size were measured. Further, a part of the granulation product was carbonized in the atmosphere of nitrogen for two hours at a. 900 C and the hardness and apparent density of the carbonized product were also measured. The results are listed in Table 1.

The hardness of the granulation products listed in Table 1 are represented by the values of the pressure at which particles of these products collapsed or began 1 deformation by gradual compression with a compressor. The hardness of the carbonized products listed in table 1 were measured according to JIS K 1474, Method of Testing Active Carbon, testing item: hardness.

JIS K 1474 hardness Summary: Put a granular sample together with stainless steel balls into a pan for hardness test, sieve the sample after the disk was shaken, measure the mass of the sample remaining on the sieve, and obtain the hardness from the ratio of the sample remaining in the original condition.

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s15 H: hardness W: the mass of the sample remaining on the sieve S: the total mass of the sample remaining on the sieve and on a sieving pan 0 o 20 EXAMPLE 2 A granulation product of 6 to 9 mesh was produced OSScSS by carrying out granulation and sieving in the same manner as in Example 1 by using the same kind of powdered bituminous coal with the exception that the powdered bituminous coal had an average particle size of 20 g m.

1 The yield of the granulation product was calculated in the same manner as in Example 1. The properties of the granulation product-were also measured in the same manner as in Example 1. The results are listed in Table 1.

EXAMPLE 3 A granulation product of 6 to 9 mesh was produced by carrying out granulation and sieving in the same manner as in Example 1 by using the same kind of powdered 10 bituminous coal with the exception that the powdered bituminous coal had an average particle size of 10 gt m.

The yield of the granulation product was calculated in the same manner as in Example 1. The properties of the granulation product were also measured in the same manner as in Example 1. The results are listed in Table 1.

EXAMPLE 4 A granulation product of 6 to 9 mesh was produced by carrying out granulation and sieving in the same manner S" 20 as in Example 1 with the exception that a powdered subbituminous coal having the same particle size characteristics as those in Example 1 was used. The yield of the granulation product was calculated in the same manner as in Example 1. The properties of the granulation product were also measured in the same manner as in Example 1 1. The results are listed in Table 1.

EXAMPLE A granulation product of 6 to 9 mesh was produced by carrying out granulation and sieving in the same manner as in Example 1 With the exception that a powdered semianthracite coal having the same particle size characteristics as those in Example 1 was used. The yield of the granulation product was calculated in the same 10 manner as in Example 1. The properties of the granulation product were also measured in the same manner as in Example 1. The results are listed in Table 1.

EXAMPLE 6 A granulation product of 6 to 9 mesh was produced by carrying out granulation and sieving in the same manner as in Example 1 with the exception that 15 kg of a petroleum fluid catalytic cracking residue (FCC residue: viscosity 35 cst) was used as the binder in place of the 20 naphtha cracking residue. The yield of the granulation product was calculated in the same manner as in Example 1.

The properties of the granulation product were also measured in the same manner as in Example 1. The results are listed in Table 1.

19 1 EXAMPLE 7 An oxidized granulation product was produced by subjecting the granulation product (6 to 9 mesh) obtained in Example 1 in the air at 50 °C for 10 hours. The properties of the oxidized granulation product were measured in the same manner as in Example 1. The results are listed in Table 1.

EXAMPLE 8 10 An oxidized granulation product was produced by subjecting the granulation product (6 to 9 mesh) obtained in Example 1 in the air at 150 °C for 6 hours. The properties of the oxidized granulation product were measured in the same manner as in Example 1. The results are listed in Table 1.

COMPARATIVE EXAMPLE 1 A granulation product of 6 to 9 mesh was produced by carrying out granulation and sieving in the same manner 0 20 as in Example 1 by using the same kind of powdered bituminous coal with the exception that the powdered bituminous coal had an average particle size of 40 g m and a maximum particle size of 160 a m and contained particles of more than 74 g m in particle size in a ratio of 47 by weight based on the total particles. The yield of the 1 granulation product was calculated in the same manner is in Example 1. The properties of the granulation product were also measured in the same manner as in Example 1. The results are listed in Table 1.

COMPARATIVE EXAMPLE 2 A granulation product of 6 to 9 mesh was produced by carrying out granulation and sieving in the same manner as in Example 1 with the exception that 15 kg of a 10 lubricant (Trade name: E-100, produced by Union Petroleum Co., Ltd.) was used as the binder in place of the naphtha cracking residue. The yield of the granulation product was calculated in the same manner aL in Example 1. The properties of the granulation product were also measured in 15 the same manner as in Example 1. The results are listed in Table 1.

S. COMPARATIVE EXAMPLE 3 A granulation product of 6 to 9 mesh was produced 20 by carrying out granulation and sieving in the same manner as In Example 1 with the exception that 15 kg of water was used as the binder in place of the naphtha cracking residue. The yield of the granulation product was calculated in the same manner as in Example 1. The properties of the granulation product were also measured in 21 1 the same manner as in Example 1. The results are listed in Table 1.

Table 1 Examples Comparative examples 1 2 3 4 5 6 7 8 1 2 3 Average 30 20 10 30 30 30 30 30 40 30 particle size (A m) Maximum 95 90 70 93 97 95 95 95 160 95 particle size (i m) Ratio of 8 6 0 7 8 8 8 8 47 8 8 particles 74 g m or more (wt%) 15 Oxidation no no no no no no 50C 150'C no no no treatment 10h 6h Yield 53 60 65 58 50 52 53 53 33 49 Apparent 0,69 0.70 0.72 0,67 0,74 0.70 0.69 0.70 060 0.67 0.72 density (g/cc) Hardness-1 510 550 600 530 510 500 750 800 200 400 (g) Hardness-2 96 96 98 95 95 96 97 97 88 86 Hardness-l: the hardness of granulation product Hardness-2: the hardness of carbonized product o

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940323,p:\oper\dab33876.speX2

Claims

1. A process for granulating a coal powder, comprising granulating a coal powder in the presence of a thermal cracking residue or catalytic cracking residue as a binder by using a high speed agitated granulator, the coal powder having an average particle size of not more than 30 pm and a maximum particle size of not more than 100 pm, an? not more than by weight of the coal powder having a particle size of not less than 74 pm and the thermal cracking residue or catalytic cracking residue having a viscosity of not more than 1,000 cst.

2. The process of claim 1, wherein the coal powder is selected from the group consisting of a powdered sub- bituminous coal, a powdered bituminous coal, a powdered semianthracite coal, a powdered anthracite coal and a mixture thereof. 20

3. The process of claim 1 or claim 2, wherein the thermal cracking residue or catalytic cracking residue has a viscosity of 15 to 100 cst.

S4. The process of any one of the preceding claims, wherein 25 the thermal cracking residue or catalytic cracking residue is selected from the group consisting of a petroleum fluid catalytic cracking residue, a naphtha cracking residue, an ethylene bottom oil and a mixture thereof. «o 30

5. The process of any one of the preceding claims, wherein the thermal cracking residue or catalytic cracking residue is used in an amount of 10 to 60% by weight based, on the amount of the coal powder. 35

6. The process of any oe preo g laims, wherein the thermal cracking residu or catalefic crciing residue has a viscosity of 15 to 100 c t, is slee'd from the group S940323,p:\oper\dab,33876.spe,22 T£ r0l -23- consisting of a petroleum fluid catalytic cracking residue, a naphtha cracking residue, an ethylene bottom oil and a mixture thereof, and is used in an amount of 10 to 60% by weight based on the amount of the coal powder.

7. The process of claim 6, wherein the coal powder is selected from the group consisting of a powdered sub- bituminous coal, a powdered bituminous coal and a powdered semianthracite coal, and the thermal cracking residue or catalytic cracking residue is selected from the group consisting of a petroleum fluid catalytic cracking residue and a naphtha cracking residue.

8. The process of claim 1, wherein the. coal granules produced by the granulation by using the high speed agitated granulator are subjected to an oxidation treatment at a temperature of 50 to 150 0 C. "•00

9. The process of claim 8, wherein the ox iAetment 20 is carried out by using an oxygen-cont i s havin an oxygen concentration of 1 to 21% by volue. 5 C o, 0-

10. The process of claim 8 or claim 9, wh 1qal? powder is selected form the group consisti g of owdered 25 sub-bituminous coal, a powdered bituminous al, a powdered semianthracite coal, a powdered anthracite coal and a mixture thereof. 0*

11. The proccius of any one of claims 8 to 10, wherein the S 30 thermal cracking residue or catalytic cracking residue has a viscosicy of 15 to 100 cst.

12. The process of any one of claims 8 to 11, wherein the thermal cracking residue or catalytic cracking residue is 35 selected from the group consisting of a petroleum fluid catalytic cracking residue, a naphtha cracking residue, an ethylene bottom oil and a mixture thereof. S940323,p:\oper\dab,33876.spe,23 -24-

13. The process of any one of claims 8 to 12, wherein the thermal cracking residue or catalytic cracking residue is used in an amount of 10 to 60% by weight based on the amount of the coal powder.

14. The process of claim 10, wherein the thermal cracking residue or catalytic cracking residue has a viscosity of to 100 cst, is selected from the group consisting of a petroleum fluid catalytic cracking residue, a naphtha cracking residue, an ethylene bottom oil and a mixture thereof, and is used in an amount of 10 to 60% by weight based on the amount of the coal powder.

The process of claim 14, wherein the coal powder is selected from the group consisting of a powdered sub- bituminous coal, powdered bituminous coal and a powdered semianthracite coal, and the thermal cracking residue or catalytic cracking residue is selected from the group consisting of a petroleum fluid catalytic cracking residue and 20 a naphtha cracking residue. o

16. A process for granulating coal powder substantially as hereinbefore described with reference to the Examples (excluding the Comparative Examples). S*

17- Coal powder when produced in accordance with any one of the preceding claims. as 1 S DATED this 23rd day of March, 1994 Idemitsu Kosan Co., Ltd. u 35 By Its Patent Attorneys O DAVIES COLLISON CAVE 940323,p:\oper~dab,33876.spe,24 1 ABSTRACT OF THE DISCLOSURE Spherical granules of coal powder which have high density, high mechanical strength and a uniform particle size are obtained by a process comprising granulating a coal powder in the presence of a thermal cracking residue by using a high speed agitated granulator, the coal powder having an average particle size of not more than 30 U m and a maximum particle size of not more than 100 g m, and not 10 more than 10 by weight of the coal powder having a particle size of not less than 74 t m. o