An Improved Artificial Stone, and Method of Manufacturing same.
Year: 1898

page_text: Date of Application, 10th Jan., 1898-Accepted, 18th June, 1898
COMPLETE SPECIFICATION.
An Improved Artificial Stone, and Method of Manufacturing same.
I, WILLIAM ALEXANDER OAKLEY, of Penkivil Street, Bondi, near Sydney, in the
Colony of New South Wales, Architect and Engineer, do hereby declare the nature
of my 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 a cheaply manufactured and highly serviceable artificial
stone or stone goods of any desired shape or configuration and to the method of
manufacturing the same.
This improved artificial stone consists of the combination or intermixture of
natural earths of opposite chemical attributes in the presence of heat so that the
component parts will flux and chemically combine as in nature into stone. The
component parts or the fluxing material may be moulded or cast in moulds or other-
wise formed into blocks or slabs of desired shapes.
In order to the manufacture of this improved artificial stone disintegrating
siliceous rocks marls, shale earths kaolins sands or clays after reduction to powder
are intermixed with their natural fluxes or reducing agents such as calcareous
earths alkaline earths fluor spar felspathic granite or clays. The two series
mentioned must each of course have some chemical attribute common to said series
say for instance they might be what are termed acid or siliceous disintegrating rocks
&c. or they might be what are termed alkaline or calcareous rocks &c. The inter-
mixtures made are that materials of the acid group or the first series are combined
with materials of the alkaline group or the second series and those of the alkaline
group or the second series combined with those of the acid group or the first series.
In some cases the materials of these two series are found in nature already mixed
and so alone they only require fusing or chemically uniting by the action of heat.
The proportions of these materials artificially mixed are regulated in practice by
the exact composition of the materials used and the desirability for quick fusion
or fluxing and by the degree of hardness desired in the resulting stone."
The intermixture of above mentioned component parts of opposite chemical
attributes is the base of this improved artificial stone but to produce such artificial
stone of different colors and with natural marks such as marble granite and the like
other materials are added. To produce marble with several veins and markings
several portions of the component parts either of the first or second series above
mentioned and while dry are mixed with different metallic oxides or other coloring
matters which will when burnt give the desired hue or tint. These several portions
each having a different coloring oxide or other materials in its composition while in
plastic form are mixed together and then the resultant colored materials consisting
of materials of the first and second series above mentioned are intermixed as herein-
before set out and moulded or cast and burnt so as to flux or chemically unite the
admixtures. For granites instead of combining the various differently colored
materials in plastic state are combined dry.
The intermixed materials above mentioned when it is desired to produce slabs is

page_text: sufficiently heated that it will take a molten plastic form when it may be run or
cast upon heated beds or tables and rolled out and thus given the form desired
being afterwards removed to a cooling furnace and annealed. To produce blocks
the heat is just sufficient to allow of the molten fluxed materials being lifted or
run on or into moulds and being pressed into same and then the resultant is cooled
in an annealing furnace.
Fire clay or other refractory moulds coated or lined with plumbago or other like
material which will resist the corrosive action of the fluxes are used in order to
prevent cracking of the material when cooling and to prevent the pro-
duct adhering to the moulds. To produce other blocks such as those
of regular shape for building purposes and the like the intermixed materials
of the first and second series above mentioned either colored or otherwise are com-
bined in plastic form and moulded in the desired shapes. The moulded blocks
being removed from the moulds are dried and then burnt but it is necessary in the
burning in the kiln or oven that these moulded articles should be supported by
other means than their own bodies say for instance by other bodies of same size and
shape alternating with them in a stack these other bodies being composed of say
ordinary clay or fire clay or the like. To produce articles of an irregular shape
such as statuary and other forms the intermixed materials above mentioned in the
plastic form are cast in moulds though they might be dry and be pressed into the
mould. The resultant moulded articles are dried then coated with plumbago or
the like anti-corrosive substance and encased in plastic fire clay or other refractory
material which will when dry form a protective casing to the article in the presence
of heat.
Powdered charcoal or other form of carbon or as a substitute therefor some other
quickly reducing agent is added to the clays or materials of the first and second
series above mentioned in a dry state in order to increase the hardness of the
resultant artificial stone. According to the quantity of charcoal or reducing agent
added an artificial stone of any degree of hardness even equal to the hardest flint is
produced. About 3% (per cent.) of charcoal produces a hardness in the artificial
stone equal to all ordinary requirements.
The heat which is necessary for the fluxing of the materials above mentioned is
produced in any ordinary way. When the articles are to be cast off the molten mass
the mixture is heated in an ordinary furnace. When the articles are moulded in a
plastic state they are burned or fused in a kiln of ordinary construction. Articles
or moulded materials however might be fused either in moulds or in an open furnace
or combined in an electric furnace or by means of electric heat.
Though the different natural earths divided into those of the first and second
series hereinbefore mentioned whose intermixture will enable a flux or chemical
affinity to take place in the presence of heat have been stated yet for the clearer
understanding of this invention the following is an example of a mixture of the
materials of the first and second series above mentioned for the production of
artificial stone. Disintegrated felspathic granite or clay containing say from 70
to 75 per cent. of silica and from 10 to 20 per centum of alumina and say small
quantities (not less than five per centum) of magnesia potash or soda and traces of
lime is powdered and carefully intermixed in a dry state in equal proportions with
any ordinary aluminous earth or clay. Upon the application of heat these two
materials would naturally flux or chemically combine and go to stone and the
color of the resulting stone would be regulated by the quantities and nature of the
metallic oxides contained in either of the materials. If the disintegrated granites
or clays or aluminous earths did not contain sufficient fluxing material that is
sufficient materials of opposite chemical attributes as above mentioned it would be
necessary to add to the mixture such materials as would according to the nature of
the ingredients cause fluxing or chemical affinity to take place. For instance if the
clay were of the acid or siliceous nature then an alkaline or calcareous material such
as lime or other alkali would be added but if the base were of a calcareous or alkaline
nature then an acid flux such as silica or fluor spar would be added.

page_text: 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:-
First. The combination or intermixture of natural earths of opposite chemical
attributes whether as found in nature or artificially mixed subjected to heat in the
manner and for the purposes substantially as herein described and explained.
Second. The combination or intermixture of disintegrating rock, marl, shale,
earths, kaolin, sands or clays of an acid or siliceous nature with earths rocks and
clays of an alkaline or calcareous nature and fluxing or chemically uniting same in
the manner and for the purposes substantially as herein described and explained.
Third. The combination or intermixture of disintegrating rock, marl, shale,
carths, kaolin, sands or clay of an alkaline or calcareous nature with earths rocks
and clays of an acid or siliceous nature and fluxing or chemically uniting same in
the manner and for the purposes substantially as herein described and explained.
Fourth. The addition to the combinations or intermixture set forth in the preced-
ing claim of metallic oxides or other coloring matters which will when burnt give a
hue or tint and the combination together of two or more portions of the different
materials each having a different coloring oxide or other material in its composition
in a plastic form and in a dry state in the manner and for the purposes substantially
as herein described and explained.
Fifth. Articles produced of the combination or intermixture of materials as set
forth in the preceding claims cast in a molten plastic form in fire clay or other
refractory moulds coated or lined with plumbago or like material which will resist
the corrosive action of the fluxes in the manner and for the purposes substantially
as herein described and explained.
Sixth. Articles produced of the combinations or intermixtures of materials as
set forth in the preceding claims moulded in plastic form coated with plumbago or
the like encased in fire clay and burnt in the manner and for the purposes substan-
tially as herein described and explained.
Seventh. Articles produced of the combinations or intermixtures of materials as
set forth in the preceding claims moulded in plastic form and burnt in a kiln or
oven (in stacks) alternating with similar bodies composed of ordinary clay or fire
clay and the like in the manner and for the purposes substantially as herein
described and explained.
Eighth. The combinations or intermixtures of materials as set forth in the
preceding claims hardened by the addition (before subjection to heat) of charcoal
or like reducing agent in the manner and for the purposes substantially as herein
described and explained.
Dated this Fourth day of December One thousand eight hundred and ninety-
seven.
Witnesses:-
FRED. WALSII.
PERCY NEWELL,
W. A. OAKLEY.
Patent Law Clerk.
G. F. Redfern & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.