Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The prevent invention rules to method of producing
coal or coal mixtures of a fine granular size prefQrEIbly
coal Utah he cowl or coal mixer are safe to store and
in particular are safe to ~:r~nYport by rouge rail, end sea
For purpose of this application, coal Eddy coal mix-
lures of a foe granular size refer to a granular size of
up to 3 mm; coal do or pulverized coal ho a growler size
ox up to 071 mull (100 p)- Road and rail try port rears to
transport from one region to Ankara, which lodger
10 periods of tîm~9 in contrast Jo tr~n~por~ within a plot.
The transport of fill gained coal end coal dust way
up to now carried out in suitable containers accompanied
by the use of on inert gas, for example nitrogen or another
gay kenning lets than 8 - 10 % oxygen. It has Also been
trued lo swore and transport with safety coal end coal
mixture wealth a protective go In this connection,
see the dehydration methods of US, Patent 3,723,079 end
4~192,650, ~ccord~n~ to which coal, which has been dried
Jo a rudely moisture of 0 Jo it subjected to a steam
~re~mQst at 100 to 115C Gil the moisture content of
toe Goal ha gain roached 2 - 10 % (US. Patent 49192,650),
or thy dry coal it treated at 175 - 225~C with a quantity
of oxygen equaling OHS 8 % of the White of the oily
and the thus pretreated coy rehydraPed with a quint
of water equalli~g 1.5 - 6 Z of toe weighs of the coal
The "H3ndbuch dyes KokRreiw~ens" (~dbo~k of Coka;~ven-
Plant Oppression Vol. I, 1955, Page 62, 63, de~cribe3
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laboratory tests for a so-called preliminary oxidation. This
handbook states that easily oxidizable gas coal (in which the
volatile constituents are greater than 15% water- and ash-
free) are preliminarily oxidized at 250C in approximately lo
to 20 hours. In "Gluc~auf", 1950, Pages 988, 989, the
treatment of fat coal (in which the volatile constituents are
12 - 14~ water- and ash-free) and of anthracite are described
in order to make it possible to store them. In this case, a
thermal treatment is effected for 24 hours at a temperature
of 125 - 275C.
It is an object of the present invention to provide a
method for producing the aforementioned coal and coal
mixtures, the storage and transport of which complies with
safety regulations, yet does not require any costly
expenditures during storage and transport. In other words,
the coal or coal mixtures produced according to the method of
the present invention should be capable of being stored in a
conventional manner and of being transported by road, rail,
or sea, without requiring additional expensive precautionary
measures.
This object, and other objects and advantages of the
present invention, will appear more clearly from the
following specification.
By one aspect of the present invention there is provided
a method of producing coal of a fine granular size of up to
I mm which is safe for transporting and storage, said
method comprising the steps of: drying said coal in a
thermal treatment zone for attaining a maximum moisture
content up to I by weight by subjecting said coal to said
thermal treatment; carrying out said thermal treatment in an
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atmosphere in a range of 12~ to 21~ oxygen employed to treat
said coal having up to 10~ volatile constituents; said coal
being further subjected to a thermal aging step which
comprises heating said coal for a time in a range of from 30
sec. to 1 hr. at a temperature in a range of between 100 C
and a temperature which is below the ignition temperature of
said coal and including steps of heating said coal for from 5
to 30 sec., at a temperature which is above ignition
temperature of said coal, and thereafter to a temperature
slightly below said ignition temperature of said coal; and
providing coal in which the proportion thereof having a
granular size of less than a predetermined amount is greater
than the proportion thereof having a granular size of greater
than said predetermined amount.
By another aspect of this invention there is provided a
method of producing a coal mixture of a fine granular size,
said method comprising the steps of: drying the coal mixture
for attaining a maximum moisture content up to I by weight
at temperatures above ignition temperature thereof, said
temperatures being applied briefly to at least one ingredient
thereof which constitutes up to 50% of the weight of said
mixture and having up to 15% volatile constituents; and at
least one residual constituent having up to 10~ volatile
constituents; subjecting said coal mixture to further
alternative thermal treatment for a time ranging from 30 sec.
to l hr. at a temperature of between 100C and slightly below
the ignition temperature of said coal mixture; and
selectively heating said coal mixture for from 5 to 20 sec.,
at a temperature above the ignition temperature of said coal
0 mixture, to a temperature below said ignition temperature;
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and carrying out both said thermal treatments in an atmosphere containing at least 12~ 2-
Pursuant to another aspect of this invention there is provided in a method of producing safe-to-store and safe-to-
transport coal or coal mixtures with a granular size up to 3
mm, which, being redried in an 02-containing atmosphere are
subjected to a heat treatment, without any ignition
occurring, the improvement comprising therewith, that a coal
or coal mixture with ingredients including one having
volatile constituents up to 10~, which is formed up to 50% by
weight of one or more mixture ingredients with up to 15%
volatile constituents and a residue ingredient with up to 10
volatile constituents, being subjected to treatment in an
atmosphere with 12 to 20.95% 2 -portion for a duration of 30
sec. to 1 hr. at a temperature between 100~ C and below
ignition temperature thereof or for a duration of 5 to 30
seconds above ignition temperature thereof, whereby the water
content before or during the heat treatment is adjusted to a
maximum of 3%.
Pursuant to yet another aspect of this invention there
is provided a method of producing coal of a fine granular
size of up to 3.0 mm which is safe for transporting and
storage, said method having improvement therewith in
combination comprising the steps of: providing coal in which
the proportion thereof having a granular size of less than 45
mu is greater than the proportion thereof having a granular
size of greater than 45 I; drying said coal in a main thermal
treatment zone for attaining a maximum moisture content up to
I by weight; subjecting said coal to said thermal treatment
at a temperature in a range of from 20~ below to 20% above
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said ignition temperature thereof; carrying out said main
thermal treatment in an atmosphere containing at least 12% 2
in an atmosphere in a range of 12~ to 21~ oxygen applied
relative to said coal having up to 10~ volatile constituents;
carrying out said main heat treatment for more than one
minute utilizing a fluidized bed chamber, a drum, a stream
tube drier, or a belt drier; and subjecting said coal for
aging thereof additionally to further thermal treatment
consisting of heating said coal for a time in a range of from
30 sec. to 1 hr. at a temperature in a range of between 100
C and a temperature which is slightly below the ignition
temperature of said coal and including steps of heating said
coal for from 5 to 30 sec., at a temperature which is above
ignition temperature of said coal, and thereafter to a
temperature slightly below said ignition temperature of said
coal.
According to further features of the present invention,
which serve to improve and further develop the aforementioned
features, the coal or coal mixture may be sub-
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jetted to a thermal treatment at a temperature of from 20 %
below to 20 % above the ignition temperature. The coal or
coal mixture may be redried, and may then be subjected
to a thermal treatment for thirty seconds to one hour at
temperatures between 100C sod slightly below the ignition
temperature of the dust.
The thermal trimmed may be effected in a normal at-
misfire, or in an atmosphere of higher than 12 % oxygen.
The redrying of the coal or coal mixture which is freshly
mined or is mQi~t from preparation, can be effected in a
known manner a temperatures above the ignition temperature.
The proportion of the coal or coal mixture which is
less than 45 may be greater than the proportion which is
greater than 45 pro The coal or coal mixture may have a
granular size which is less than or equal to 45 p.
The coal may be thermally treated in a fluidized bed
chamber, drum, a stream tube drier or on a belt drier
for more than one minute
Fine coal may be redried to a water content of 2-3 %,
whereupon it may be sorted and the resulting coal may be
thermally treated for thirty seconds to one hour
The coal or coal mixture may be limited in its therm
treatment, in that it is not heated to a temperature of
higher than 30% above its ignition temperature
The cowl may be redried to a water content of 2-3 %,
and then subjected to a thermal treatment for more than
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10 seconds at temperature above the ignition temperature
of the coal.
The refrain to coal or coal mixtures refer to water-
free and ash-free coal and coal mixtures.
The thermal treatment of coal is known for various
other purposes and for other than being able to safely store
or transport it. The precise thermal if atment of certain
coals and coal mixtures pursuant to the present invention
deports not only from the rehydratio~ and long term pro-
luminary oxidation, but is also in contrast to a thermaltreatment~or drying coal which has bee freshly mined and
us most from preparation, with which latter thermal treat-
mint the coal it subjected to a shock heating for 1 - 2
second at a temperature which is on~iderably greater
the the ignition point of She coal. An ignition of the
coal does not tyke place due to the short tome of treat-
mint, especially, however, due to the heat-flux density.
Coal preliminarily dried in this manner does jot meet
the requirements for safety during storage and transport
of the coal or coal mixtures.
Since for the use of cowl or a coal mixture, especial-
lye cowl dust, generally a water content of at most 2 - 3 %
by weigh is required, the treatment of freshly mined and
moistly prepared cowl or a coal mixture can be effected in
such a way what during the aforementioned thermal treat-
mint the water content is reduced to 2 - 3 %. In another
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procedure, the preliminary drying can be effected first
and the thermal treatment can then be effected, so that
the water content is reduced to 2 - 3 % or less. The
criteria of the water content us not crucial for the
therms treatment itself, i.e. the thermal treatment is
not directed primarily at achieving a certain water con-
tent, but rather the main thing to the aging of the coal
by the thermal treatment over a certain period of time.
Nevertheless, the length of time and the temperature of
the thermal treatment can be adjusted in such a way that
the coal which is treated at the same time Allah contains
the desired water context. The primrose "length of
treatment" and 'temperature" can therefore be selected
while observing the data end limit and con be altered
as a function of one another.
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