Improvements in the Manufacture of Artificial Stone.
Year: 1896

page_text: This Print is in accordance with the Original Specification as it stals after
Amendment (under Section 11 of the Patents, &c., Act, 1883), as required
by the decision of the Comptroller General of the 29th day of March 1897.
Date of Application, 15th Sept., 1896-Accepted, 12th Dec., 1996
COMPLETE SPECIFICATION (AMENDED).
Improvements in the Manufacture of Artificial Stone.
I, JAMES GRUNHUT, of 12 King Street, Leicester, in the County of Leicester
Chemist, 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 :-
The manufacture of artificial stone, and especially sand-stone, has given rise to
a great number of processes and formulæ of manufacture and treatment; but there
does not exist at present, so far as I am aware, any process or formula for
manufacturing, in a simple and certain way, artificial stone which fulfils all the
conditions required of a thoroughly good stone; because such stone as heretofore
produced has been too soft and tender and deficient in strength.
The object of my improvements is to provide means for producing sand-stone of
very hom geneous structure and great compactness of the agglomerated materials,
whilst possessing the porosity characteristic of the best sand-stones.
In the manufacture of the improved stone, when the latter is not to be specially
coloured, four elements only are employed namely, sand, lime, steam and sulphur.
The action of the steam and sulphur on the two other elements, namely the sand
and lime is particularly advantageous in obtaining the complete solidification of
these bodies even to the interior of the pores. The proportions of the two
elements, steam and sulphur, are varied according to the nature of the other two
component bodies, and of the products required; that is to say according as the
stone is required to be more or less hard and strong.
For the purposes of my invention I mix together sand, lime, and finely powdered
sulphur in a very dry state, and put the mixture, still in a dry state, into moulds
which I place in a team-tight chamber, into which I then introduce high pressure
steam mixed or not, according to circumstances, with sulphur vapour. By these
means I obtain an artificial stone of a quality equal to that of natural stone.
The apparatus for carrying the invention into effect may be varied according to
circumstances; but that shown in elevation in the accompanying drawing has been
found suitable for the purpose. In the drawing, A represents the steam tight
chamber containing the moulds in which the masses of mixed sand, lime and
powdered sulphur are enclosed in order to be exposed to the action of the steam
and sulphur vapour, and where the solidification of the artificial stone takes place.
B is a mixing vessel in which the steam and sulphur vapour are mixed together.
C is the steam boiler supplying the steam of water and D is the pipe supplying the
sulphur vapour from any suitable source of supply.
The steam coming from the steam boiler C is admitted by the tap or valve fand
the sulphur vapour coming by the pipe D is admitted by the tap or-valve é into

page_text: the vessel B where the two vapours mix; and according as the said taps or valves
are opened or closed the relative proportions of steam and sulphur vapour are
regulated.
The mixture of steam and sulphur vapour passes away from the mixing vessel B
through the tap or valve g, and enters at a b c and d, or at any other required
number of places, into the mould vessel A, where the induration of the masses of
sand, lime and sulphur is effected by the combined action of the steam and sulphur
vapour.
The water of condensation which forms in the vessel B may be drawn off through
a blow-off tap or valve h.
The various vessels are of course provided with pressure gauges, water-level
indicators, and other apparatus necessary to the proper supervision of the working
of the apparatus.
Instead of sand any silicate suitable for the manufacture of artificial stone may
be employed.
Instead of mixing powdered sulphur with the sand and lime I sometimes mix
therewith powdered sulphate of iron, copper, aluminum or ammonium, or powdered
sulphide of sodium.
Instead of mixing the steam with sulphur vapour as above described I sometimes
impregnate it with sulphur, sulphate or iron, copper, aluminum or ammonium, or
with sulphide of sodium, by placing those materials in a suitable vessel inter-
mediate between the chamber A and the steam boiler C, and causing the steam, in
its passage from the boiler C to the chamber A, to pass through or in contact with
the said materials in the said intermediate vessel.
The proportions of the materials employed may be varied according circum-
stances, for example, good results may be obtained by mixing together 100 parts
of sand or other silica, 12 to 15 parts of lime, and 4 parts of sulphur.
The pressure of the steam employed may also be varied according to circum-
stances, but pressures of from four to six atmospheres are suitable for most
purposes.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I would have it understood
that I am aware that it has before been proposed to treat artificial stone by placing
it in a chamber and subjecting it to the action of steam which may have been
previously passed through a mass of sulphur and I make no claim to such method,
but I declare that what I claim is :-
First. The manufacture of artificial stone by mixing together in a dry state
sard, lime, and finely powdered sulphur, placing the mixture, while still in that
state, in suitable moulds, and then subjecting the mixture to the action of steam,
substantially as described.
Second. In the manufacture of artificial stone in accordance with the first
claiming clause hereof the employment of sulphur vapour in combination with
the steam, substantially as described.
Third. The manufacture of artificial stone by mixing together, in a dry state,
sand, lime and finely powdered sulphate of iron, copper, aluminum or ammonium
or sulphide of sodium, placing the mixture, while still in that state, in suitable
moulds, and then subjecting the mixture to the action of steam or of steam
combined with sulphate of iron, copper, aluminum or ammonium, or sulphide of
sodium, substantially as described.
Dated this 15th day of September 1896.
JAMES GRUNHUT,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.