Improvements in and in the Manufacture of Artificial Stone and in Furnaces for Burning the same.
Year: 1898

page_text: Date of Application, 23rd Feb.,
1898
Complete Specification Loft 18th May 1898 Accented 16th July, 1898
Improvements in and in the Manufacture of Artificial Stone and in
Furnaces for Burning the same.
I, CARL SCHOENFELDER, of 14, Rosensteingasse, Vienna, in the Empire of Austria,
Brick and Tile Manufacturer, do hereby declare the nature of this invention
to be as follows:-
-
This invention has for its object an improved artificial stone substance which
is capable of being pressed and cast and which after having been burnt has an
appearance very similar to marble. Further this improved artificial stone is, like
marble, capable of being ground and polished, and may be worked also like marble
but has a considerably higher degree of hardness than marble, and articles made
of this artificial stone may be decorated in such a way as to resist the weather.
The articles produced from or by means of this artificial stone substance may
be removed from the mould 30 minutes after casting entirely hardened and set.
They have the inestimable property of not shrinking when drying, and not warping
or cracking even when exposed unequally to heat.
These improved artificial stones as opposed to those at present employed have a
fine fresh coloured homogeneous porcelain-like appearance and have a very great
power of resisting the influences of weather.
This artificial stone substance is therefore more particularly suited for
outer and inner wall coverings and ornamentations for decorating house facades
and the rooms of buildings and as a covering for the floor, as well as for plaster-
ings, roofing tiles and reproduction of objects of art and various other building
purposes.
The improved artificial stone substance consists essentially of silica, kaolin
powder, sulphate of lime and an addition of glass and fluorite and is made into a
product capable of being pressed and cast in the manner hereinafter described.
The articles made of the artificial stone substance must after drying he baked in
a suitably constructed furnace or oven in a so-called oxygen or oxidizing flame in
order to obtain the above mentioned properties.
For producing the artificial stone substance:

page_text: substances are roasted in a current of air heated to 110° C. until 75% of the
water of crystallization is driven off. The mass is then stirred with 1-8% of
alum water and poured into the moulds. The articles formed in this manner are
then dried and again burnt in the furnace hereinafter described. The quantity
of the addition of glass, fluorite and alum, depends on the quality or condition of
the materials employed and essentially affects the degree of hardness of the
product.
All articles made from the artificial stone herein before described may be de-
corated with muffle and stove colours as well as by the use of sgraffitto. The
desired colour may also be imparted to the artificial stone substance by the addition
of coloured silicates.
The furnace employed for burning this improved artificial stone substance must
be constructed in such a way that sufficient oxygen is conveyed into the burning
chamber, whilst the consumption of smoke is thoroughly effected, so that in a
clear fire the superficial glaze of the artificial stone substance (by slagging or
running together) may be melted smooth. Further the furnace must be so
arranged that any deformation or irregular burning of the goods by an unequal
application of heat is entirely avoided.
Further this improved furnace may be immediately converted without any
alteration into a furnace with open fire or into a muffle furnace in which the entire
inner chamber forms the muffle itself.
The improved furnace is shown in the accompanying drawings, in which
Figure 1 is a longitudinal section:
Figure 2 a horizontal section on the line rx of Figure 1;
Figure 3 a horizontal section on the line yy of Figure 1;
Figure 4 a cross section on the line - of Figure 1, and
Figure 5 an end view of the improved furnace.
h
The fire or rather the fire gases pass from the furnace chamber a through
passages b beneath the burning chamber floor plate e into vertical passages and
reach the generator or generator chamber g through further horizontal passages e
formed in the walls of the burning chamber. In this generator chamber g air
supply passages open from the outside so that here the furnace gases can come
in contact with fresh oxygen by which means on the one hand a thorough com-
bustion of the smoke and on the other hand a sufficiently oxidizing flame results,
which flame passes through the inlet hole into the actual burning chamber k,
in which the articles made of the artificial stone substance are placed. After the
goods have been inserted the insertion hole i is closed by means of a perforated
double door j, whilst the entrance s is bricked up in the ordinary way. The
furnace gases pass finally through the perforated plate into the flue and
chimney 7. m are the furnace doors, n the ash chamber, o the grate and small
passages serving for regulating the furnace.
If the furnace is to be burnt with an open fire, that is to say one passing right
through the roof, passages f which run from the generator chamber g to the smoke
passage are closed, and as already stated and shown the entrance or insertion
hole is closed with a perforated double plate.
If the furnace is to be used as a muffle furnace the inlet hole i, after the insertion
of the goods, is entirely bricked up and the roof passages f opened so that the
furnace gases passing from the chamber y pass through these passages f into the
flue l.

page_text: Improvements in and in the Manufacture of Artificial Stone and in
Furnaces for Burning the same.
I, CARL SCHOENFELDER, of 14, Rosensteingasse, Vienna, in the Empire of Austria,
Brick and Tile Manufacturer, 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 has for its object an improved artificial stone substance which
is capable of being pressed and cast and which after having been burnt has an
appearance very similar to marble. Further this improved artificial stone is, like
marble, capable of being ground and polished, and may be worked also like marble
but has a considerably higher degree of hardness than marble and articles made
of this artificial stone may be decorated in such a way as to resist the weather.
The articles produced from or by means of this artificial stone substance may
be removed from the mould 30 minutes after casting entirely hardened and set.
They have the inestimable property of not shrinking when drying, and not warping
or cracking even when exposed unequally to heat."
These improved artificial stones as opposed to those at present employed have a
fine fresh coloured homogeneous porcelain-like appearance and have a very great
power of resisting the influences of weather.
This artificial stone substance is therefore more particularly suited for sculptures,
outer and inner wall coverings and ornamentations for decorating house facades
and the rooms of buildings and as a covering for the floor, as well as for plaster-
ings, roofing tiles and reproduction of objects of art and various other building
purposes.
The improved artificial stone substance consists essentially of silica, kaolin
powder, sulphate of lime and an addition of glass and fluorite and is made into a
product capable of being pressed and cast in the manner hereinafter described.
The articles made of the artificial stone substance must after drying be baked in
a suitably constructed furnace or oven in a so-called oxygen or oxidizing flame in
order to obtain the above mentioned properties.
For producing the artificial stone substance:

page_text: the materials employed and essentially affects the degree of hardness of the
product.
All articles made from the artificial stone herein before described may be de-
corated with muffle and stove colours as well as by the use of sgraffitto. The
desired colour may also be imparted to the artificial stone substance by the addition
of coloured silicates.
The furnace employed for burning this improved artificial stone substance must
be constructed. in such a way that sufficient oxygen is conveyed into the burning
chamber, whilst the consumption of smoke is thoroughly effected, so that in a
clear fire the superficial glaze of the artificial stone substance (by slagging or
running together) may be melted smooth. Further the furnace must be so
arranged that any deformation or irregular burning of the goods by an unequal
application of heat is entirely avoided.
Further this improved furnace may be immediately converted without any
alteration into a furnace with open fire or into a muffle furnace in which the entire
inner chamber forms the muffle itself.
The improved furnace is shown in the drawings accompanying the Provisional
Specification, in which,
Figure 1 is a longitudinal section:
Figure 2, a horizontal section on the line of Figure 1;
Figure 3, a horizontal section on the line y-y of Figure 1;
Figure 4, a cross section on the line
of Figure 1; and
Figure 5, an end view of the improved furnace.
air
The fire or rather the fire gases pass from the furnace chamber a through
passages beneath the burning chamber floor plate c into vertical passages & and
reach the generator or generator chamber g through further horizontal passages e
formed in the walls of the burning chamber. In this generator chamber
supply passages open from the outside so that here the furnace gases can come
in contact with fresh oxygen by which means on the one hand a thorough com-
bustion of the smoke and on the other hand a sufficiently oxidizing flame results,
which flame passes through the inlet hole i into the actual burning chamber k,
in which the articles made of the artificial stone substance are placed. After the
goods have been inserted the insertion hole i is closed by means of a perforated
double door j whilst the entrance s is bricked up in the ordinary way. The
furnace gases pass finally through the perforated plate into the flue and
chimney 7. m are the furnace doors, n the ash chamber, o the grate and ? small
passages serving for regulating the furnace.
If the furnace is to be burnt with an open fire, that is to say one passing right
through, the roof passages f which run from the generator chamber g to the smoke
passage are closed, and as already stated and shown the entrance or insertion
hole i is closed with a perforated double plate.
If the furnace is to be used as a muffle furnace the inlet hole i, after the insertion
of the goods, is entirely bricked up and the roof passages f opened so that the
furnace gases passing from the chamber g pass through these passages f into the
flue 7.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. An artificial stone or stone substance consisting of a mixture of silica, kaolin
powder and sulphate of lime, to which is added glass and fluorite which substance
is either compressed in moulds in a dry condition under hydraulic pressure, or
after having been roasted is stirred up with alum water and run into moulds,
after which the articles made from the artificial stone formed in either manner
are dried and burnt, substantially as hereinbefore described.

page_text: 416
600- 630
2. The process of manufacturing artificial stone which consists in
446 parts by weight of silica
"
"
ور
"
kaolin powder
984-1014
وو
"
" sulphate of lime
100-140
"
99
"
"
45-100
"
"
"
"
glass
fluorite,
being (a) ground finely together and compressed when dry in moulds under
hydraulic pressure; or (b) after grinding, being roasted in a current of air heated
to 110° until the mixture has lost 75% of the water of crystallization, and then
stirred with 1-8% of alum water and run into moulds; or (c) by the mixture
being made in either manner into artificial stone and then dried and burnt; sub-
stantially as hereinbefore described.
3. For carrying out the hereinbefore described process for making artificial stone
and for burning the said artificial stone, a peculiar furnace in which the furnace
gases pass through passages (e) in the furnace walls and playing round the burning
chamber (k) are mixed in a chamber (9) with air and oxygen before entering the
said burning chamber so that a completely clear flame rich; in oxygen passes
through the burning chamber (k) when the furnace is burnt with an open fire
substantially as hereinbefore described.
4. In the furnace herein before described, the arrangement of passages (f) in the
roof dome which connect the generator chamber (9) with the flue () with the
object of carrying off the furnace gases from the generator chamber (g) direct to
the chimney in case the furnace is to be employed as a muffle furnace, substantially
as hereinbefore described.
Dated thia 17th day of Nov 1900
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.