[0001] This invention relates to an in-line method for the upgrading of coal and the formation
of a coal-in-oil combustible fuel therefrom.
[0002] It has already been proposed in United States Patent No. 3,665,066, dated May 23,
1972, "Beneficiation of Coals", Capes et al, to beneficiate a coal slurry effluent
by mixing a bridging liquid (light hydrocarbon oil) with coal fines and agitating
the formed mixture in an aqueous medium to cause agglomeration of the coal particles.
The coal particle agglomerates are then at least partially dewatered and fed to a
balling device, together with balling nuclei of relative coarse coal particles and
binding oil (heavy hydrocarbon oil) to form a balled product in which each ball comprises
at least one balling nucleus in association with coal particles from the agglomerates.
The coal fines may contain significant proportions of hydrophilic (or oleo- phobic)
impurity or ash-forming particles composed of silica, alumina, pyrite, etc. to which
the functional groups of the light hydrocarbon oil bridging liquid are incapable of
attaching themselves so that when the coal particle agglomerates are formed, these
particles remain suspended in the water and are thus effectively separated from the
coal particles.
[0003] While the process disclosed in the Capes et al Patent has proved to be useful for
the production of relatively coarse, balled coal products in the range 1/8 inch (3.2
mm) to 1 inch (25.4 mm) which are sufficiently strong to be transported in the balled
form without the balls disintegrating or releasing coal dust, there is a need for
a process for the production of relatively fine, impurity-liberated, balled coal products
having an average size no greater than of the order of 3 mm in order that the balls
will easily disperse in oil to form a combustible fuel comprising a coal-in-oil suspension.
Impurity-liberated coal-in-oil suspensions would be a useful alternative fuel for
existing oil-fired electrical generating facilities resulting in a saving in the oil
consumption. Other possible uses for these suspensions are marine fuels, fuel for
industrial boilers and as injected fuels for blast furnaces.
[0004] In Canadian Patent No. 1,020,880, dated November 15, 1977, "A method of displacing
liquid suspendant of a particulate material. liquid suspendant mixture by micro-agglomeration"
Capes et al, there is described an in-line, one-stage, agglomerating process for producing
microagglomerates of coal fines which is particularly useful for minimizing the moisture
content of coal-in-oil suspensions for transportation along long distance pipelines.
While this process is useful for the purpose for which it was developed, there is
still a need for this process to be developed further to produce a combustible fuel
comprising an impurity-liberated, coal-in-oil suspension wherein the retention of
larger amounts of the residual moisture content in the fuel from the original coal-in-water
slurry can be achieved together with a more accurate control of the larger amount.
One reason for this may be that the residual moisture content of the coal-in-oil suspension
explodes in a combustion chamber and this possibly aids in dispersing the oil and
coal and thereby improving combustion efficiency.
[0005] Controlled moisture content could also be useful when the coal-in-oil suspension
is subjected to vibratory energy such as, for example, in burners which use vibratory
energy to increase the combustion efficiency in combustion chambers.
[0006] French patent application No. 2 323 754 describes a process for preparing a liquid
fuel comprising a suspension of coal particles in a hydrocarbon oil by treating an
aqueous suspension of coal particles in a first agglomeration device, separating the
agglomerates, disintegrating the agglomerates and re-agglomerating them in a second
agglomeration device, separating these agglomerates and taking them up in a hydrocarbon
fuel. The agglomeration step is repeated in order to obtain the required degree of
deashing. After the first agglomeration step the largest coal particles are separated
ground and recirculated.
[0007] According to the present invention there is provided a method for the continuous
beneficiation of coal and the continuous formation of a coal-in-oil combustible fuel
therefrom, in which coal is comminuted in water to produce a coal-in-water slurry,
the coal-in-water slurry is mixed with an agglomerating liquid to agglomerate the
coal particles, and the agglomerates are separated out and mixed with oil to form
a coal-in-oil combustible fuel, characterized in that the method comprises the following
steps:
a) comminuting coal in water, to produce a coal-in-water slurry comprising impurity-liberated
coal particles at least as fine as 40 µm weight means particle size, then
b) mixing the coal-in-water slurry with light oil as agglomerating liquid having a
specific gravity of less than 1 g/cm3 to agglomerate the impurity-liberated coal particles into relatively small agglomerates
and primarily dissociate inorganic impurities and some water therefrom, the light
oil agglomerating liquid being added at not more than 20 wt % of the total weight
of the solids of the coal-in-water slurry, then
c) separating the impurity-liberated relatively small agglomerates from the dissociated
inorganic impurities and water, and
d) mixing the separated, relatively small impurity-liberated agglomerates with heavy
fuel oil, having a specific gravity greater than 0.9 g/cm3 and greater than that of the light oil, as agglomerating liquid to produce relatively
larger agglomerates comprising an average size no greater than 3 mm and primarily
dissociate water with some inorganic impurities which were present in the relatively
small impurity-liberated agglomerates and leave a residual amount of at least 5 wt
% water in the relatively larger agglomerates, then
e) separating the relatively larger agglomerates from the dissociated water and inorganic
impurities, and then
f) mixing the separated, relatively larger agglomerates with make-up heavy oil additive
to form a coal-in-oil combustible fuel.
[0008] In the accompanying drawing which illustrates, by way of example, an embodiment of
the present invention there is shown a flow diagram of a method for the continuous
beneficiation of coal and the continuous formation of a coal-in-oil combustible fuel
therefrom.
[0009] In Figure 1 there is shown a method for continuous beneficiation of coal and the
continuous formation of a coal-in-oil combustible fuel therefrom, comprising:
a) comminuting coal-in-water, in a wet mill 1, to produce a coal-in-water slurry 2
comprising impurity-liberated coal particles at least as fine as 40,um weight mean
particle size, then
b) mixing the coal-in-water slurry 2, in three stirring devices 4 to 6 arranged in
cascade, with light oil 8 having a specific gravity of less than 1 g/cm3, as agglomerating liquid to micro- agglomerate (that is to make into relatively small
agglomerates) the impurity-liberated coal particles and to dissociate primarily a
large amount of inorganic impurities and some water therefrom, the light oil agglomerating
liquid 8 being added at not more than 20 wt % of the total weight of the solids of
the coal-in-water slurry 2, then
c) separating, on a dewatering screen 10 the micro-agglomerated impurity-liberated
coal from the dissociated inorganic impurities and water, then
d) mixing the separated, micro-agglomerated impurity-liberated coal 12, in a stirrer
14, with heavy fuel oil 16, having a specific gravity greater than 0.9 g/cm3, as agglomerating liquid to produce relative larger agglomerates comprising an average
size no greater than 3 mm and to dissociate primarily water with some inorganic impurities
which were present in the micro-agglomerated, impurity-liberated coal and leave a
residual amount of at least 5 wt % water in the relatively larger agglomerates, then
e) separating the relatively larger agglomerates on a vibrating screen 18, from the
dissociated water and inorganic impurities, and then
f) mixing the separated, relatively larger agglomerates 20, in a mixer 22, with make-up,
heavy oil additive 24 to form a coal-in-oil combustible fuel 26.
[0010] A dry pulverizer 28 is used for the initial stage of grinding since this will generally
pulverize coal faster and in a smaller equipment volume than with wet methods, although
wet grinding may be used throughout, if desired. During pulverization, the coat is
ground down to a required particle size sufficient to effect separation or dissociation
of coal particles and impurities.
[0011] Coal to be pulverized is fed from a storage hopper 30 to the dry pulverizer 28 which
is swept with air from a supply 32. The swept air, with entrained pulverized coal,
is fed from the pulverizer 28 to a wet scrubber 34. Water containing the pulverized
coal is fed from the wet scrubber 34 to the wet mill 1 while air, which has been scrubbed
free from the pulverized coal in the wet scrubber 34, is exhausted therefrom at 36.
[0012] As previously stated the coal-in-water slurry 2 from the wet mill 1 is stirred in
three mixing devices 4 to 6 arranged in cascade. One mixing device could be used provided
that the residence time for the coal of the coal-in-water slurry 2 therein to be micro-agglomerated
is tolerable. With the embodiment shown in Figure 1, a residence time of four minutes
was required and so the three mixing devices 4 to 6 were provided.
[0013] The first mixing device 4 is a high shear mixing device and may be a conventional
turbine mixer. The first mixing device 4 is used to disperse the light oil agglomerating
liquid 8 in the coal-in-water slurry 2 and give an initial mixing.
[0014] The second and third mixing devices 5 and 6 respectively, are relatively lower blade
speed, intermediate intensity mixing devices as compared with the mixing device 4
and are for producing the micro-agglomerates. It should be noted that in different
embodiments of the present invention, only one lower intermediate- intensity mixing
device is necessary and in other embodiments different mixing devices may be used,
such as, for example, one or more emulsifying units with or without one or more lower,
intermediate intensity mixing devices.
[0015] The light oil agglomerating liquid additive 8 is fed to the first mixing device 4
from a storage tank 38.
[0016] As previously stated the micro-agglomerated, impurity-liberated coal is separated
from the dissociated components comprising primarily a large amount of inorganic impurities
and some water on the screen 10, which in this embodiment is a stationary, inclined
screen down which the separated, micro-agglom- .erated, impurity-liberated coal rolls
and emerges as micro-agglomerates 12 while the dissociated inorganic impurities and
water, designated 40, drain through the screen and are conveyed to a settling pond
42. A vibrating screen separator or wet cyclone separator could be used at this stage
if the micro-agglomerates possess sufficient strength not to break up in such apparatus.
[0017] The embodiment shown in Figure 1 is arranged to recycle most of the water from delivery
40 to the settling tank 42, together with make-up water 44 which is fed thereto. The
water 46 from the settling tank provides feed to the wet scrubber 34, wet mill 1 and
the first mixing device 4.
[0018] The micro-agglomerates 12 then pass to the mixing device 14 which is also a relatively
lower blade speed, intermediate intensity mixing device as compared with the mixing
device 4.
[0019] The relatively larger agglomerates are separated from the dissociated water and inorganic
impurities on the vibrating screen 18 because the relatively larger agglomerates have
sufficient strength not to break up on the vibrating screen 18, which is an efficient
separator for the purpose. A wet cyclone separator, other types of screens, etc.,
could also be used at this stage if desired.
[0020] The dissociated water and inorganic impurities designated 48, drain through the vibrating
screen 18 and are conveyed to a separation tank 50 from which a portion 52 of the
water is returned to the stirrer 14 while the remaining water and inorganic impurities
54 are conveyed to the settling pond 42.
[0021] The reason why the water portion 52 is returned to the mixing device 14 is to ensure
that sufficient water is delivered, with the relatively larger agglomerates, to the
vibrating screen 18 to ensure that the inorganic impurities are thoroughly washed
from the relatively larger agglomerates. This substantially reduces the possibility
of inorganic impurities being carried over the vibrating screen 18 with the relatively
larger agglomerates. In addition, the water in mixing device 14 would usually be heated
to about 60°C to reduce the viscosity of the heavy fuel oil 16. Recirculation of water
portion 52 avoids loss of thermal energy in discarded hot water.
[0022] The mixer 22, to which the relatively larger agglomerates 20 are conveyed in this
embodiment is a stationary, cylindrical vessel having a mixing device rotating about
a horizontal axis. Other types of mixers may also be used such as, for example, a
paddle type mixer.
[0023] The coal-in-oil combustible fuel 26 is stored in an agitated condition in a holding
tank 56 from which it is withdrawn by a pump 58 at the desired rate for consumption
as a combustible fuel in, for example, an electrical power generating installation
(not shown). The method can be matched to the desired rate of consumption of the combustible
fuel so that the holding tank 56 is merely provided for storage to accommodate any
fluctuations in the production of the coal-in-oil combustible fuel or the consumption
thereof.
[0024] Details of an example using the method shown in Figure 1 to beneficiate coal mined
from Minto, New Brunswick, Canada and to form a coal-in-oil combustible fuel therefrom
will now be given.
[0025] A typical analysis of the Minto coal is given below which shows that this is a coal
having a high ash and sulphur content.
[0026] The weight ratio of air to coal fed to the dry pulveriser 28 was in the range 1.5:1
to 2:1. 40 wt % coal and 60 wt % water were present in the wet mill 1.
[0027] The first mixing device 4 was fed with 20 wt % coal, 3 wt % No. 2 fuel oil and 77
wt % water.
[0028] The plant was a pilot plant designed to be capable of treating 100 Imperial gallons/min.
(455 I/min.) of slurry 2, which is equivalent to about 6 tons/hour (5.44 tonnes/hour)
of coal solids (including impurities) based on the 20 wt % slurry fed to the first
mixing device 4. The blades of the high shear mixing device 4, which were driven by
a 5 HP motor at 3,220 rpm, comprised two groups of four high shear impeller blades,
two of which are shown for each group and designated 60 to 63, which tapered radially
outwardly towards truncated extremities. The high shear impeller blades 60 and 62
were mounted in an 18 inch (0.46 m) internal diameter tank 64 having a 35 inch (0.89
m) height with an annular baffle 66 between the impeller blades 60 and 62 and four
vertical baffles, two of which are shown and designated 68 and 70, equally spaced
therearound to enhance their shearing effect on the coal-in-water slurry 2.
[0029] The four blades of each of the relatively lower blade speed, intermediate intensity
mixing devices 5, and 6 and 14, which were driven by a 5 HP motor at 280 rpm comprised
pitched, turbine impeller blades two of which are shown and designated 72 and 74.
The blades 72 and 74 were mounted in a 40 in. (1.02 m) internal diameter vessel having
a 40 in. (1.02 m) overflow height with four vertical baffles, two of which are shown
and designated 76 and 78, equally spaced around the blades 72 and 74 to enhance their
shearing effect.
[0030] The dissociated inorganic impurities and water, designated 40, mainly comprised 96
wt % water and 3 wt % ash and sulphur as the main inorganic impurities together with
1 wt % unagglomerated combustible matter.
[0031] The relatively larger agglomerates produced by mixer 14 comprised 70 wt % coal, 20
wt % oil and 10 wt % water to which was added sufficient No. 6 fuel oil in the mixer
22 for the coal-in-oil combustible fuel 26 to comprise a coal/oil weight ratio of
40/60.
[0032] Tests have shown that using apparatus of the type shown in Figure 1, then:
i) the preferred blade tip speed of the high shear impeller blades 60 to 63 is in
the range of 10 m/sec. to 30 m/sec. better still of 20 m/sec. to 25 m/sec.
ii) the preferred blade tip speed of the pitched, turbine impeller blades 72 and 74
is up to 15 m/sec.
[0033] Preferred light oils/as agglomerating liquid are No. 2 fuel oil and diesel oil. Other
light oils as agglomerating liquid are, for example, light petroleum fractions, kerosene,
coke oven light oil and light crude and residual and waste oils. Preferred heavy fuel
oils as agglomerating liquid are No. 6 fuel oil and heavy residual oils. Other heavy
fuel oils as agglomerating liquid are, for example, crude oils and coke oven tar.
[0034] The quantity of light oil agglomerating liquid additive used will depend upon the
type of coal being processed and how finely the coal must be ground to produce impurity-liberated
coal particles. While a greater quantity of light oil agglomerating liquid additive
could be used than 20 wt % of the total weight of solids of the coal-in-water slurry
the desirable thing according to the present invention is that only up to 20 wt %
need be used so that the final coal-in-oil combustible fuel will contain, for example,
the maximum amount of heavy oil for which an oil-fired installation was originally
designed, when the coal-in-oil combustible fuel is for use in this manner.
1. An in-line method for the beneficiation of coal and the formation of a coal-in-oil
combustible fuel therefrom, in which coal is comminuted in water to produce a coal-in-water
slurry (2), the coal-in-water slurry is mixed with an agglomerating liquid (8) to
agglomerate the coal particles, and the agglomerates (20) are separated out and mixed
with oil to form a coal-in-oil combustible fuel (26), characterized in that the method
comprises the following steps:
a) comminuting coal in water to produce a coal-in-water slurry (2) comprising impurity-liberated
coal particles at least as fine as 40,um weight means particle size, then
b) mixing the coal-in-water slurry (2) with light oil (8) as agglomerating liquid
having a specific gravity of less than 1 g/cm3 to agglomerate the impurity-liberated coal particles into relatively small agglomerates
(12) and primarily dissociate inorganic impurities and some water therefrom, the light
oil agglomerating liquid being added at not more than 20 wt % of the total weight
of the solids of the coal-in-water slurry, then
c) separating the impurity-liberated relatively small agglomerates (12) from the dissociated
inorganic impurities and water, then
d) mixing the separated, relatively small impurity-liberated agglomerates (12) with
heavy fuel oil (16), having a specific gravity greater than 0.9 g/cm3 and greater than that of the light oil (8), as agglomerating liquid to produce relatively
larger agglomerates (20) comprising an average size no greater than 3 mm and primarily
dissociate water with some inorganic impurities which were present in the relatively
small impurity-liberated agglomerates and leave a residual amount of at least 5 wt
% water in the relatively larger agglomerates, then
e) separating the relatively larger agglomerates (20) from the dissociated water and
inorganic impurities, and then
f) mixing the separated, relatively larger agglomerates (20) with make-up heavy oil
additive (24) to form a coal-in-oil combustible fuel (26).
2. A method according to claim 1 further characterized in that the coal is initially
pulverized in a dry pulverizer (28), air is scrubbed free from the dry, pulverized
coal in a wet scrubber (34) and then the scrubbed, pulverized coal is comminuted in
water to produce the coal-in-water slurry (2).
3. A method according to claim 1 or 2, further characterized in that the coal-in-water
slurry (2) is stirred with light oil agglomerating liquid (8) initially in a high
shear stirring device (4), to give an initial mixing, and then in at least one relatively
lower blade speed, intermediate-intensity, mixing device (5, 6).
4. A method according to claim 1, 2 or 3 wherein the light oil (8) as agglomerating
liquid is selected from the group consisting of No. 2 fuel oil and diesel oil.
5. A method according to claim 1, 2, 3 or 4 wherein the heavy oil (16) as agglomerating
liquid is selected from the group consisting of No. 6 fuel oil and heavy residual
oils.
1. Procédé en continue pour traiter du charbon afin de produire un combustible constitué
par une suspension de charbon dans de l'huile, selon lequel du charbon est pulvérisé
dans le l'eau pour former une suspension de charbon dans de l'eau (2), la suspension
de charbon dans de l'eau est mélangée avec une liquide agglomérant (8) destiné à agglomérer
les particules de charbon, et les agglomérats (20) sont séparés et mélangés à de l'huile
pour former un combustible constitué par une suspension de charbon dans de l'huile
(26), caractérisé en ce qu'il comprend les étapes suivantes:
a) pulvériser du charbon dans de l'eau pour former une suspension de charbon dans
l'eau (2) comprenant des particules de charbon purifié dont la taille pour une particule
de poids moyen, est au moins aussi faible que 40 µm, puis
b) mélanger la suspension de charbon dans l'eau (2) avec de l'huile légère (8) en
tant que liquide agglomérant dont la masse spécifique est inférieure à 1 g/cm3 pour agglomérer les particules de charbon purifié en agglomérats (12) relativement
petits et en dissocier essentiellement des impuretés inorganiques et de l'eau, l'huile
légère en tant que liquide agglomérant étant ajoutée dans une quantité non supérieure
à 20 % en poids du poids total des solides contenus dans la suspension de charbon
dans l'eau, puis
c) séparer les agglomérats (12) relativement petits purifiés des impuretés inorganiques
dissociées et de l'eau, puis
d) mélanger les agglomérats (12) relativement petits purifiés et séparés avec du mazout
lourd (16) dont la masse spécifique est supérieure à 0,9 g/cm3 et supérieure à celle de l'huile légère (8), en tant que liquide agglomérant pour
former des agglomérats relativement gros dont la dimension moyenne n'est pas supérieure
à 3 mm, et dissocier principalement de l'eau et des impuretés inorganiques qui étaient
contenues dans les agglomérats relativement petis et purifiés, et laisser une quantité
résiduelle d'au moins 5 % en poids d'eau dans les agglomérats relativement gros, puis
e) séparer les agglomérats relativement, gros (20) de l'eau et des impuretés inorganiques
dissociées, puis
f) mélanger les agglomérats relativement gros (20) séparés avec de l'huile lourde
additionnelle (24) de complément pour former un combustible (26) constitué par une
suspension de charbon dans l'huile.
2. Procédé selon la revendication 1, caractérisé en ce que le charbon est pulvérisé
initialement dans un pulvérisateur à sec (28), de l'air est extrait du charbon pulvérisé
sec dans un épurateur par voie humide (34), puis le charbon pulvérisé et épuré est
broyé dans de l'eau pour former la suspension de charbon dans l'eau (2).
3. Procédé selon la revendication 1 ou la revendication 2, caractérisé en ce que la
suspension de charbon dans l'eau (2) est remuée initialement avec l'huile légère agglomérante
(8) dans un dispositif agitateur à cisaillement élevé, pour donner un mélange initial,
puis dans au moins un dispositif mélanger (5, 6) du puissance intermédiaire à vitesser
d'ailettes relativement plus basse.
4. Procédé selon l'une quelconque des revendications 1 à 3, dans lequel l'huile légère
(8), en tant que liquide agglomérant, est choisie parmi le groupe constitué par le
mazout N° 2 et la gazole.
5. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel l'huile lourde
(16), en tant que liquide agglomérant, est choisie parmi le groupe constitué par le
mazout N° 6 et les huiles résiduelles lourdes.
1. Ein kontinuierliches Verfahren für die Veredelung von Kohle und die Bildung eines
Kohle-in-ÖI-Brennstoffs daraus, bei dem Kohle in Wasser zerkleinert wird zum Erzeugen
einer Kohle-in-Wasser-Aufschlemmung (2), die mit einer Agglomerationsflüssigkeit (8)
gemischt wird, zum Agglomerieren der Kohlepartikel und bei dem die Agglomerate (20)
ausgeschieden werden und mit Öl gemischt werden zur Bildung eines Kohle-in-ÖI-Brennstoffs
(26), dadurch gekennzeichnet, daß das Verfahren die folgenden Schritte umfaßt:
a) Zerkleinern von Kohle in Wasser zum Erzeugen einer Kohle-in-Wasser-Aufschlemmung
(2) mit verunreinigungsfreien Kohlepartikeln mit einer Feinheit mindestens bei 40,um
gewichteter mittlerer Partikelgröße, danach
b) Mischen der Kohle-in-Wasser-Aufschlemmung (2) mit Leichtöl (8) als agglomerationsflüssigkeit
mit einer spezifischen Schwere von weniger als 1 g/cm3 zum agglomerieren der verunreinigungsfreien Kohlepartikel in relativ kleine Agglomerate
(12) und primär dissoziierte anorganische Verunreinigungen und etwas Wasser davon,
wobei das als Agglomerationsflüssigkeit dienende Leichtöl mit nicht mehr als 20 Gew.%
des Gesamtgewichts der Feststoffe der Kohle-in-Wasser-Aufschlemmung zugesetzt wird,
danach
c) Abtrennen der verunreinigungsfreien relativ kleinen Agglomerate (12) von den dissoziierten
anorganischen Verunreinigungen und dem Wasser, danach
d) Mischen der abgetrennten Relativ kleinen verunreinigungsfreien Agglomerate (12)
mit Schweröl (16) mit einer spezifischen Schwere, größer als 0,9 g/cm3 und höher als derjenigen des Leichtöls (8) als Agglomerationsflüssigkeit zum Erzeugen
relativ größerer Agglomerate (20) mit einer mittleren Größe von nicht größer als 3
mm und primär dissoziiertem Wasser mit einigen anorganischen Verunreinigungen, die
in den relativ kleinen verrunreinigungsgreien Agglomeraten enthalten waren unter Belassung
einer Restmenge an mindestens 5 Gew.% Wasser in den relativ großen Agglomeraten, danach
e) Abtrennen der relativ großen Agglomerate (20) von dem dissoziierten Wasser und
den anorganischen Verunreinigungen und danach
f) Mischen der abgetrennten relatic großen Agglomerate (20) mit einem Schwerölendzuschlag
(24) zur Bildung eines Kohle-in-ÖI-Brennstoffs (26).
2. Verfahren nach Anspruch 1, weiter, dadurch gekennzeichnet, daß die Kohle zunächst
in einer Trockenpulverisiervorrichtung (28) pulverisiert wird, daß Luft von der trockenen
pulverisierten Kohle in einem Naßreiniger (34) frei gewaschen wird und dass die gewaschene
pulverisierte Kohle in Wasser zerkleinert wird zum Erzeugen der Kohle-in-Wasser-Aufschlemmung
(2).
3. Verfahren nach Anspruch 1 oder 2, weiter dadurch gekennzeichnet, daß die Kohle-in-Wasser
Aufschlemmung (2) mit der Leichtöl-Agglomerationsflüssigkeit (8) zunächst in einer
Rührvorrichtung (4) mit hoher Scherung verrührt wird zum Erzeugen einer ersten Mischung
und dann in mindesstens einer Mischvorrichtung (5, 6) mit relativ niedriger Flügelgeschwindigkeit
und mittlerer Intensität.
4. Verfahren nach anspruch 1, 2 oder 3, bei dem das als Agglomerationsflüssigkeit
dienenden Leichtöl (8) ausgewählt wird aus der Gruppe, bestehend aus Nr. 2 Brennöl
und Dieselöl.
5. Verfahren nach Anspruch 1, 2, 3 oder 4, bei dem das als Agglomerationsflüssigkeit
dienende Schweröl (16) ausgewählt wird aus der Gruppe, bestehend aus Nr. 6-Brennöl
und schweren Restölen.