An Improved Process for the Manufacture of Artificial Stone.
Year: 1899

page_text: PROVISIONAL
SPECIFICATION.
An Improved Process for the Manufacture of Artificial Stone.
We, FERNAND GERNAERT and CILARLES LIBERT, both of 3, Rue d'Arlon,
Brussels, in the Kingdom of Belgium, Engineers, do, hereby declare the nature
of this invention to be as follows:-
This invention relates to the manufacture of artificial stone which is rendered
frost proof owing to an important improvement upon the known process which
consists in submitting natural sand and other substances mixed with a certain
proportion of lime to a cooking action by means of steam under pressure in an
autoclave. This process does not produce frost proof stone, that is to say
stone of a texture or density such that it is not capable of absorbing a suffi-
ciently large quantity of water to cause its disaggregation of frost.
This absorption of water by artificial stone manufactured from natural sand
is attributable to the physical condition of the natural sand which exists in
the form of particles or grains of greater or less size covered by a fine glazed
layer which offers opposition to its decomposition and therefore to a more
intimate combination with the swelling lime, so that although strongly agglo-
merated, the mass retains a spongy formation giving rise to the absorption of
water rendering the stone liable to be cracked by frost.
In accordance with our novel process for the manufacture of artificial stone
which, will not be affected by frost, the decomposition of the sand which is
necessary for this purpose is effected mechanically and prior to its mixture
with the lime by means of a suitable crushing of the sand which breaks the
vitrious film and lays open its reduced internal parts thus forming with the
external parts a homogenous powder which is capable of extremely intimate
combination with the lime under the action of steam or hot water for the pur-
pose of forming an agglomerate mass free from sponginess, in other words
of a density such that any absorption of water is obviated, thus rendering the
artificial stone produced frost proof.
The decomposition of the sand may, however, be effected by means other
than mechanical crushing, for example by the "busting" in ice water of sand
heated to a high temperature, but as mechanical crushing is more economical
in practice and obtains the desired end, this method of operation is preferable,
the more so as it enables the decomposition of the sand to be graduated in
accordance with the degree of density desired in the stone produced.
In addition to the advantage of rendering the artificial stone produced by
this process frost proof or dense in texture, our novel artificial stone offers far
greater resistance to traction and compression; in other words, by reason of
the more intimate combination with the lime, it is cohesive to a greatly in-
creased degree and, from this last point of view, good results may be obtained
even with natural sand by working it into a homogenous mixture with suitable

page_text: proportions of decomposed sand, in accordance with the use to which the pro-
ducts are to be put.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.
An Improved Process for the Manufacture of Artificial Stone.
We, FERNAND GERNAERT and CHARLES LIBERT, both of 3, Rue d'Arlon,
Brussels, in the Kingdom of Belgium, Engineers, 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 which is rendered
frost proof owing to an important improvement upon the known process which
consists in submitting natural sand and other substances mixed with a certain
proportion of lime to a cooking action by means of steam under pressure in an
autoclave. This process does not produce frost proof stone, that is to say
stone of a texture or density such that it is not capable of absorbing a suffi-
ciently large quantity of water to cause its disaggregation by frost.
This absorption of water by artificial stone manufactured from natural sand
is attributable to the physical condition of the natural sand which exists in
the form of particles or grains of greater or less size covered by a fine glazed
layer which offers opposition to its decomposition and therefore to a more
intimate combination with the swelling lime, so that although strongly agglo-
merated, the mass retains a spongy formation giving rise to the absorption of
water rendering the stone liable to be cracked by frost.
In accordance with our novel process for the manufacture of artificial stone
which will not be affected by frost, the decomposition of the sand which is
necessary for this purpose is effected mechanically and prior to its mixture
with the lime by means of a suitable crushing of the sand which breaks the
vitrous film and lays open its reduced internal parts thus forming with the
external parts a homogeneous powder which is capable of extremely intimate
combination with the lime under the action of steam or hot water for the pur-
pose of forming an agglomerate mass free from sponginess, in other words
of a density such that any absorption of water is obviated, thus rendering the
artificial stone produced frost proof.
The decomposition of the sand may, however, be effected by means other
than mechanical crushing, for example by the "bursting" in ice water of sand
heated to a high temperature, but as mechanical crushing is more economical
in practice and obtains the desired end, this method of operation is preferable,
the more so as it also enables the decomposition of the sand to be graduated in
accordance with the degree of density desired in the stone produced.
In addition to the advantage of rendering the artificial stone produced by
this process frost proof or dense in texture, our novel artificial stone offers far
greater resistance to traction and compression; in other words, by reason of
the more intimate combination with the lime, it is cohesive to a greatly in-
creased degree and, from this last point of view, good results may be obtained
even with natural sand by working it into a homogeneous mixture with suitable
proportions of decomposed sand, in accordance with the use to which the pro-
ducts are to be put.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is:-
An improved process for the manufacture of artificial stone by the treatment
of mixtures of sand, lime and other substances by means of steam, characterized
by the substitution, in the processes in accordance with known methods, (either
wholly or in part) of sand which has been decomposed to a suitable degree of
fineness, for natural sand, substantially as above described and for the purpose
indicated.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.