Note: Descriptions are shown in the official language in which they were submitted.
16~6;~967
,`~
'',',.'-,'."'
Summary of the Invention `
. : '., ~, ,. ', ,,
The essential object of the invention is to cover the
otherwise exposed surface of bulk or piled-up coal with a ;~
flexible, water resistant and force resistant blanket of coal tar ~
in a solid condition. This is accomplished by essentially a two ,
step operation in which the exposed surface of the coal is pre-
I wetted with a wetting agent and in which immediately thereafter
I ~ the coal tar emulsion is applied to the coal. The wetting agent ,~
~enables the subsequently applied emulsion to rapidly wet the
~10~ coal, form a continuous film thereover,;and to then break to set ,i~
~ up a solid but 1exible seaIing layer over the coal which is
! essentially water resistant and which will withstand substantial ;;
! ~ mechanical abuse such as that imparted by a moving coal car.
The underlying object~of the invention is to prevent ~ ;
the present substantial economic losses of coal dust and coal
fines to ambient air.
. ~
Other objects and advantages of the invention are as
follows: to provide a low cost coal coating process employing
.,, ~ . . ', ' : :
c A --1 ~
. . '"'~
' ~ '"''~ -
~06Z~67 : ~
¦low cost materials; to provide a coal coating material which may -
~be readily pumped, stored for extended periods without change, and
, lapplied readily through spray nozzles and the like; to provide a
' Icoal coating material which forms a strong flexible layer on the ;
coal granules and particles which is able to withstand vibration
land to retain moisture in the coal; to provide a coal coating
¦material which is insoluble in water after its application; to `
Iprovide a coaL coating material which becomes immediately stable
A'' lupon application; and to provide a coal coating material which
Iwill break up reasonably well when a coal car is dumped.
- I These and other objects and advantages of the invention
~ ¦will be apparent from the following description of the invention.
,., l ,.' ': ' -~
I The preferred coal tar for the present process is the
!~" ¦crude coal tar produced from medium-volatile Balmer coal in a
¦horizontal retort coke oven. This tar has a relatively low cost
¦and is a semi-fluid material as produced. It emulsifies well
with water when a cationic emulsifying agent is employed. A wide
variety of such cationic emulsifying agents may be satisfactorily
¦ employed in the coating material of the invention, i.e.
l ~a) Long chain aliphatic diamine quaternary ammonium
¦ compounds.
~t l (b) Alkyl trimethyl quaternary ammonium compounds. ~ ~;
(c) Alkyl propylene diamines.
;' I (d) N-alkyl trimethylene diamine polyoxyethylene
¦ compounds.
¦ The preferred type of such agent is a fatty amine agent
such as E-ll, a long chain aliphatic diamine quaternary ammonium
formulation. E-ll is a product of Armour.
.- . ''~'"'.,''' '~': ,
i':'~ " ', ' "
.. "~'.:' "''~ '
I -2~
`~ I ~~'~,,' ,:,, ~,~ ':
3, :
~ :- 106Z96~ ~
The basic sto~k material is made up by mixing 40-70~/0 by
¦weight of crude coal tar~ 60-30% by weight of water, and 0.5 -
¦ 2.~/o based on total emulsion volume of the cationic emulsifying
agent. ~ 50-50 tar-water mix with 1.7% of the agent is preferred. `
¦The emulsion can be made with a continuous homogenizer when the `
water containing the emulsifying agent and tar are fed separately
¦ to the shear zone. Good emulsions may also be obtained by using r
¦batch homogenizers of various types.
¦ The emulsion by itself will wet the coal, but somewhat
` 10 ¦slowly, and since less than one minute is available for a binder
Ito be applied to and adsorbed by the coal surface (the time
¦within which it should be possible to spray-coat a loaded coal
car passing beneath a spray head) it is desirable to make use of
~ la wetting agent which permits rapid contact of the emulsion with
r I the coal. In addition the type of coating formed by using the
i ¦ emulsion by itself does not perform well as a dust suppressant.
~ I ~ ~, ,
, I For this purpose, any wetting agent may be employed
¦ which has the properties of wetting the coal, promoting the
formation of a full-covering film of the emulsion on the coal. ~-
¦ Cationic emulsions break on contact with a surface. It
. ¦ was not to be expected that the presence of a water solution of a
¦ non-ionic wetting agent would affect the quality of the coat tar
¦ surface formed.
¦ Surfactants which may be used as wetting agents for the
¦ coal in the coating process o the invention are as follows:
1. Nonionic
~a) Alkylphenyl-polyethoxy ethers.
I (b) Alkyl polyethoxy ethers.
¦ ~c) N, N-substituted fatty acid amides.
..
-3-
l ~ ~
6Z~67
2. Anionic ~
(a) Alkyl aryl sulfonates. ~ `
(b) Alkane sulfonates.
(c) Alkyl sulfonates with an amide intermediate
linkage.
3. Cationic
(a) Tetra-alkyl ammonium salts with at least one
long chain alkyl group.
(b) Polyethoxy alkyl amines.
(c) Dialkyl-aminoalkyl fatty acid amide.
The preferred wetting agents are the non-ionic
alkylphenyl polyethoxy ethers. Typically, a 0.03% by weight
solution of such an ether, in water is employed.
~'
~
Taking a typical loaded coal car as a working example of
the practice of the process of the invention, the surface of the
coal is first pre-wetted with about 24 U.S. gallons of water
containing 0.03% of an alkylphenyl-polyethoxy ether. Immediately 5
` thereafter about 12 gallons of the coal tar emulsion are sprayed
,s on the coal. If desired, a second application of the tar -
.~ ~ 20 emulsion may be made.
~he result of this application of the tar emulsion is the ~ ;~
formation on the coal of a surface ~ayer about 0.75 inches thick
~, made up of coal particles and coal dust bonded with coal tar.
This layer is flexible and withstands mechanical abuse of the i
magnitude encountered by heavily handled loaded coal cars.
Immediately after the application of the emulsion to the coal, the
emulsion breaks to set up a solid but flexible sealing layer over
the coal, and thereafter this layer is essentially water resistant ;
and remains in place as a cover after being subjected to wind, -
weather and vibration in a travelling rail car.
~',
'` '~,' '~': .' '
~l ~ i -4- ~
~.'',' ~ ''.
, :, '' ''
,.,
''':-'
