IMPROVEMENTS IN THE MANUFACTURE OF ASPHALTUM
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Louis Luc Péaud at the Office of the
Commissioners of Patents on the 1st September 1876. A communication from
Edouard Rocheman, of Cairo (Egypt).
LOUIS LUC PÉAUD, of Boulevard Saint Denis, No. 1, at Paris, Civil Engineer.
"IMPROVEMENTS IN THE MANUFACTURE OF ASPHALTUM."
The object of this Invention is the manufacture by novel processes of a particular
kind of asphaltum or asphalte, and its application to various purposes for which it
may be usefully employed I call my asphalte Egyptian asphalte, because it was
invented in Egypt, where it is manufactured from a product of the soil.
The essential property of this asphalte is its power of entirely resisting solar
heat without experiencing any depression in consequence of the softening of the
material under the solar influence In Egypt, for example, in front of houses
and on, terraces, places where the sun's rays being concentrated often reach a
temperature of 140° Fahrenheit, this asphalte preserves its appearance and solidity.
Trials have also shewn that it resists the action of cold, and that it does not
experience under the influence of frost any contractions resulting in fissures in the
mass.
It is to give the asphalte this property of resulting solar rays that I take as the
base of my manufacture a particular clay called in geology fossil clay, and which is
found in abundance in the old alluvial caiths of Egypt. This clay is therefore the
chief feature in my manufacture, it is to it the stability of my products is due, and
also the hardness which they offer to the trampling of men and animals as well as
to the pressure and friction of vehicles. I will, however, remark that experiments
have clearly shewn that in the manufacture of this asphalte clays of another kind,
possessing of themselves the qualities of the fossil clay of Egypt, or brought by
different means to the state of the fossil clay of Egypt for the purpose of being used
with advantage, are capable of producing the saine results in my manufacture. I
therefore include within my Invention the use of a group of clays or argillaceous
materials, which fulfil the same object as the fossil clay of Egypt to the same or
practically the same extent.
I proceed to describe my processes of manufacture employing the fossil clay of
Egypt.
Manufacture
The first onoration consiste in carefully crinding the clay either by

page_text: powder, in sifting it in order to remove foreign matters which may have got mixed
with it, and in again reducing it In this state it is necessary to be assured that it is as
dry as possible, and if it is not in this essential condition the dying must be
effected by any suitable processes which are prompt and economical; the clay is
then ready for the manufacture. I will describe the different stages of this
operation, stating the proportions of materials which from experience I consider the
most suitable to produce a good result. I use for the melting and heating or
boiling of the materials small boilers capable of holding from 600 to 700 lbs. of
materials, pitch and clay. I introduce the pitch and clay into the boiler progres-
sively in successive charges of equal weight.
1st. Charge.. On lighting the fire I put into the boiler 50 lbs. of pitch, which I
allow to melt for an hour. When it has well melted .I add 108 lbs. of fossil clay,
which I allow to heat well for an hour, taking care to stir constantly.
2nd. Charge. At the expiration of these two hours I put another 50 lbs. of pitch
into the boiler and allow it to melt, stirring the mass for half an hour, I then add
108 lbs. of clay, which I heat and stir in the mass for threo-quarters of an hour.
3rd. Charge. At the expiration of this time I add 50 lbs of pitch, which I allow
to melt, and which I stir for half an hour Then I pour into the melted mass
108 lbs. of clay which I stir and heat for an hour.
4th. Charge. I finally empty into the mass 30 lbs. of pitch, heat and stir for half
an hour, then 108 lbs. of clay and heat and stir for an hour.
When these operations are finished I add, according to the appearance of the
matter in fusion, 10 or 20 lbs of pitch, in order to give it a suitable consistence,
depending upon whether it is too dry or too thick.
To complete the operation I again heat the liquid mass for two hours, stirring it
continually in order that it may acquire as much homogeneity as possible, and that
at the same time it may not get burnt. This being finished I run the mass into
moulds to make cakes or blocks for use in the application of the asphalte to various
purposes. During all this work of boiling and mixing the temperature should be
kept at a mean of about 390° Fahrenheit. The amount of fuel employed is about
80 lbs. of coal per boiler.
Application. My Egyptian asphalte, like all asphaltes, requires the previous
preparation of the ground or surface to which it has to be applied, that is to say, a
layer of concrete about 3 or inches thick. This being well smoothed, consolidated,
and dried the layer of asphalte is applied by the ordinary processes.
To give the asphalte the desired degree of liquefaction to run it on the surface
I use wheeled or running boilers containing about 440 lbs. of asphalte, under which
I maintain a mean and constant temperature of 390° to 420° Fahrenheit.
In order to make the mass homogeneous by a regular fusion I begin when the fire
is lighted by melting 10 or 12 lbs. of pitch. I afterwards add 200 lbs. of asphalte
broken into small pieces, which I allow to melt for an hour and a half, and which I
stir without interruption for half an hour. Then I add 180 lbs of broken asphalte,
which I allow to melt for an hour and a half, with continuous working up. At the
end of this operation I add 240 lbs of sand or gravel, more or less fine, according to
the nature of the work in view I spread it on the melted mass in layers, in order
that the heat disengaged may properly dry it, and I allow it to become heated for
about an hour. By degrees the sand from its own weight disappears into the
mass, which has become more liquid. I then stir the whole vigorously for another
hour in order to have a very homogeneous and equally boiled mass; in this state I
apply the asphalte.
I have now described the process of making asphalte which I call Egyptian
asphalte, fossil clay being used therein. But, as I have already stated, and as
experiments have shewn me, I can perfectly replace the fossil clay without sensibly
changing the value of my products or their essential properties, by clays of different
kinds and origin, which I submit to preliminary operations in order to remove
certain causes which injuriously affect the manufacture, and to obtain with these
clays similar products having all the essential properties of the Egyptian asphalte
1

page_text: or analogous thereto; the scope of my Invention is therefore widened. Never-
theless all clays will not answer, and I avoid especially saliferous clays, but for
the most part, under the conditions herein-before explained, clays of all kinds
can be advantageously employed when they are sufficiently purified and carefully
dried.
Clays are in a chemical point of view hydrated or hydratiferated aluminous
silicates, sometimes mixed with more or less pure quartzy sands, on account of their
origin, which connects them with the destruction of different kinds of rocks. These
clays purified will quite answer my purpose. It follows then from this essential
consideration that the more or less fine or more or less pure clays generally
employed in the manufacture of bricks, and of fine or coarse pottery, pipes, crockery,
and porcelain, are excellent materials for the manufacture of my asphalte, also all
debris of bricks, pottery, crockery, and porcelain, broken and pulverized.
All these materials, the base of which is clay, have the property of absorbing
bituminous matters, and of forming therewith compact and resisting mixtures,
having properties such that they produce asphaltes of very good quality and capable
of being applied for various purposes.