Improvements in the Manufacture of Artificial Stone.
Year: 1896

page_text: Date of Application, 21st Feb., 1896
Complete Specification Left, 23rd Nov., 1896-Accepted, 23rd Jan., 1897
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Artificial Stone.
I, SIMON NEFFGEN, Merchant, of Mühlheim-on-the-Rhine, Germany, do hereby
declare the nature of this invention to be as follows:-
This invention relates to the manufacture of artificial stone from lime and sand,
and has for its object to produce blocks, slabs, or plates of any desired shape in
such a manner that they have a uniform colour throughout their thickness, an
that they come out of the oven or kilu with a smooth surface which does not
require any subsequent smoothing or finishing operation.
For this purpose I take slaked lime containing as little water as possible, and
mix it with quartz sand and, if necessary, with suitable argillaceous colouring
matter, in proportions depending on the nature of the same, and on the colouring
matter. I then mould the mixture into pieces of the desired shape, and place them
in the heating chamber; after which the latter is closed and made air-tight as
much as possible. I then admit steam or hot air into the heating pipes or coils, or
equivalent heaters contained in the heating chamber, and increase the heat so as to
raise the temperature to about 50° C. in the first five or six hours. This
temperature is then slowly raised to about 80° C. reaching this point after twelve
hours, and maintained for two to three hours, after which it is rapidly raised
to 95° C. This rapid increase of temperature causes the formation of a smooth
and solid layer of calcium silicate. The temperature of 95° C. is now maintained
from 4 to 6 days, according to the size of the moulded blocks contained in the
heating chamber.
In order to cool the blocks or plates which have been baked as described, I
admit air until the temperature has dropped to about 40° C., which temperature is
then maintained for some hours, after which the blocks or plates may be taken out
of the heating chamber.
Dated this 21st day of February 1896
FAIRFAX & WETTER,
Agents for the Applicant.
Improvements in the Manufacture of Artificial Stone.
I, SIMON NEFFGEN, Merchant, of Mülheim-on-the-Rhine, Germany, do hereby
declare the nature of this invention 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 the manufacture of artificial stone from lime and
sand, and has for its object to produce blocks, slabs, or plates of any desired
shape and at low cost, in such a manner that they have a uniform colour
throughout their thickness, and that they come out of the oven or kiln with
[Price 8d.1

page_text: a smooth surface which does not require any subsequent smoothing or finishing
operation.
For this purpose I take either pulverized slaked lime (CaO,H,O) and sand, or
pulverized unslaked lime (CaO) and moist sand, and (if necessary) suitable
colouring matter, in proportions depending on the nature of the raw materials.. As
colouring matter the usual earthy colours may be employed, as well as clay which
has been baked and ground (red, green, or yellow). For instance, to produce a
reddish stone, I mix 70 parts of sand with 15 parts of pulverized red clay and
15 parts of CaO.
I then mould the mixture into pieces of the desired shape by means of
suitable machines, and place them in a heating chamber containing vessels with
water, after which the said chamber is closed and made airtight as much as
possible. I then commence to heat by means of pipe coils, ribs, or equivalent
heating devices, so as to reach and maintain a temperature of about 50° C.
during the first five or six hours. This temperature is then slowly raised to
about 80° C. reaching this point after twelve hours, after which it is rapidly
raised to 95° C.
This sudden increase of temperature has for its object, to produce on the stones
a smooth outer layer.
According to the size of the moulded blocks, the latter are left in the moist
atmosphere of the heating chamber at a temperature of 95° C. for 4 to 6 days, the
said atmosphere having been rendered moist by the evaporation of the water
contained in the vessels.
The cooling of the blocks is effected by disconnecting the heater and opening
the heating chamber; when the temperature has dropped to about 40° C., it is
maintained for some time, in order that the temperature of the interior of the
blocks may be reduced also, before the surface has cooled down completely.
Subsequently the heating chamber is completely opened, and the blocks left to
cool, after which they are ready for use.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
The above described process for making artificial stones from lime and sand,
in order that the stones when taken out of the heating chamber may have a
uniform colour throughout and a smooth surface which does not require any
finishing treatment.
Dated this 20th day of November 1896.
FAIRFAX & WETTER,
433, Strand, London, Agents.