AN IMPROVED PROCESS FOR THE MANUFACTURE OF ASPHALT to be as follows
Year: 1884

page_text: I HERMANN KETTMANN, Chemist, of Eschershausen in the Dukedom of
Brunswick, German Empire do hereby declare the nature of my invention for
"AN IMPROVED PROCESS FOR THE MANUFACTURE OF ASPHALT to be as
follows:-
ม
This invention relates to an improved process for the manufacture of powdered
asphalt designed to be used for the construction of pavements by ramining, and
for similar purposes.
The means hitherto employed. for the manufacture of asphalt to be laid by
ramming (asphalte comprimé) by mixing limestone, asphalt stone or other suitable
substances, as sand, glass or the like, with bituminous substances do not enable
such an intimate and equable coating or impregnation of the stone as is
indispensable for the production of a good asphalt
In order to promote this coating and impregnation during the mixing of the
bitumen with the stone, the latter, according to this invention, is mixed, after
pulverization, with water to form a comparatively liquid mass, the bitumen being
subsequently added during the application of heat.
In consequence of the suspension of the stony material in the water, the fluid
bitumen takes hold of, and surrounds every single particle of the stony material
with much greater facility, producing an effect similar to that produced when
fat hydro-carbons are poured upon water. In the same manner that the fat
momentarily spreads upon the surface of the water, the heated bitumen, in this
process, spreads over the entire surface of the stone particles, so that during
the subsequent heating and expulsion of the water an exceedingly intimate
impregnation of the stone particles takes place.
The crude bitumen (asphalt of Trinidad, Mexican asphalt, etc) is previously to
its admixture freed from its earthy impurities, it being, according to its consistency,
mixed with heavy or light hydro carbons (such as schist-oil, or residues of naphtha)
during the application of heat in such a manner that the earthy admixtures (clay
and the like) which injure the binding power of the material are deposited, the
purified solution being drawn off.
The quantity of the hydro-carbon added is to be such that the bitumen, at a
temperature ranging between 17° and 33° Centigrade is capable of being drawn
into threads. Eventually the heating is continued until the liquid hydro carbons
are expelled and the bitumen attains the requisite consistency.

page_text: In carrying out this process, limestone, or asphalte stone containing little
bitumen, is first reduced to a fine powder and then mixed with about 40 per cent
of water to form a very liquid mass, the whole being then heated to about
50° Centigrade in a receptacle provided with an agitating apparatus. Next, the
bitumen heated to about 70° Centigrade and suitably purified, as before stated, is
added to the liquid mass, which is kept in a state of agitation, the coating of the
stone particles with bitumen taking place almost instantaneously. During the gradual
mixture of the, materials, a consistency of the mass which admits of agitation is
maintained by the addition of water at a temperature of from 60° to 70° Centigrade.
The quantity of bitumen added may amount to as much as 15 per cent of the
dry stone material.
The homogeneous mass thus obtained is, in the hot state, or after cooling, suitably
formed into blocks which aro dried in the air.
The hot fluid mass can also be spread upon a porous bed and then divided after
cooling by longitudinal and transverse cuts.
The air-dried asphalt concrete is finally exposed for a considerable time to a
temperaturo of about 100° Centigrade in a retort furnace in order to expel the last
traces of water and to effect the soaking of the stone particles as completely as
possible without decomposing the bitumen. After the cooling the said blocks are
pulverized and the material is then ready for use.
It is evident that, instead of the limestone or asphalt stone, other pulverized,
natural or artificial inaterials admitting of impregnation can be mixed with the
bitumen in the described manner and soaked, in order to produce asphalt material.
The material manufactured according to the above described process can be
employed to produce, by pressing or rolling, stones or plates for paving, roofing or
other building purposes.
"
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: I HERMANN KETTMANN of Eschershausen in the Dukedom of Brunswick, Empire
of Germany do hereby declare the nature of my invention for "AN IMPROVED.
PROCESS FOR THE MANUFACTURE OF ASPHALT" and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention relates to an improved process for the manufacture of powdered
asphalt, chiefly designed to be used in the construction of pavements by ramming
and for similar purposes.
The means hitherto employed for the manufacture of asphalt to be laid by
ramming (asphalte comprimé) by mixing limestone, asphalt-stone or other suitable
substances, as sand, glass or the like with bituminous substances do not enable
such an intimate and equable coating or impregnation of the stone as is indispensable
for the production of good asphalt.
In order to promote this coating and impregnation during the mixing of the
bitumen with the stone, the latter, according to this invention, is mixed, after pul-
verization, with water to form a thin liquid mass, the bitumen being subsequently
added during the application of the heat.
In consequence of the suspension of the stone in the water the liquid bitumen
takes hold of, and surrounds every single particle of the stone with much greater
facility than heretofore, producing an effect similar to that produced when fat
hydro-carbons are poured upon water. In the same manner that the fat
momentarily spreads upon the surface of the water, the hented bitumen, in this
process, spreads over the entire surface of the stone particles, so that during the
subsequent heating and expulsion of the water an exceedingly equable and intimate
impregnation of the stone particles takes place.
The crude bitumen (asphalt of Trinidad, Mexican asphalt or the like) is pre-
viously to its admixture freed from its earthly impurities, by mixing the same
according to its consistency, with heavy or light hydro-carbons (such as schist-oil,
or residues of naphtha) during the application of heat in such a manner that the
earthy admixtures (clay and the like) which injure the binding power of the
material are deposited, the purified solution being subsequently drawn off.
The quantity of the hydro-carbon added is to be such that the bitumen, at a
temperature ranging between 17° and 33° Centigrade is capable of being drawn
into threads. Eventually the heating is continued until the liquid hydro-carbons
are expelled and the bitumen attains the requisite consistency.
In carrying out this process limestone, or asphalt stone containing little bitumen,
is first reduced to a fine powder and then mixed with about 40 per cent of water
to form a thin liquid mass, the whole being then heated to about 50° Centigrade in
a receptacle provided with an agitating apparatus. Next, the bitumen heated to
about 70° Centigrade and suitably purified, as before stated, is added to the liquid
stone mass, which is kept in a state of agitation, the coating of stone particles with
bitumen taking place almost instantaneously. During the gradual mixing of the
materials, a consistency of the mass which admits of agitation is maintained by the

page_text: addition of water at a temperature of from 60° to 70° Centigrade. The quantity
of bitumen added may amount to as much as 15 per cent of the dry stone
material.
The homogeneous mass thus obtained is, in the hot state or after cooling, suitably
formed into blocks which are dried in the air.
The hot fluid mass can also be spread upon a level, porous bed and then divided
after cooling by longitudinal and transverse cuta.
The air-dried asphalt concrete is finally exposed for a considerable time to a
temperature of about 100° Centigrade in a retort furnace in order to expel the last
traces of water and to effect the soaking of the stone particles as completely as
possible without decomposing the bitumen. After cooling the said blocks are
pulverized and the material is then ready for use.
It is evident that, instead of the limestone or asphalt stone, other pulverized,
natural or artificial materials admitting of impregnation can be mixed with
the bitumen in the described manner and soaked, in order to produce asphalt
material.
The material manufactured according to the above described process can be
employed to produce, by pressing or rolling, stones or plates for paving, roofing or
other building purposes.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
In the manufacture of asphalt (for paving or other purposes) by nixing limestone,
asphalt stone or other natural or artificial, pulverized material admitting of
impregnation with bitumen, the process hereinbefore described consisting in
agitating the said substances whilst adding water to form a liquid mass, mixing
the latter in a warm state with inelted bitumen, subsequently removing the water
by drying, and then heating the asphalt concrete produced for the purpose of
effecting an intimate impregnation of the stone with the bitumen.
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