Improvements in Artificial Stone
Year: 1899

page_text: Improvements in Artificial Stone,
I, FRITZ GEHRE, Civil Engineer, of 117, Mainzer, Chaussee, Coblenz, in the
Kingdom of Prussia, Empire of Germany, do hereby declare the nature of this
invention to be as follows;-
It is known that magnesia cements made of magnesite and chloride of magnesia
have the disadvantage of being neither waterproof nor water resisting, nor are
they capable of resisting frost and the influence of the weather.
To obviate this defect I employ instead of magnesite, boracite and stassfurtite,
or their residues left after the chemical separation of the boron, either one of these
bodies alone, or both combined, or I may employ either boracite, or stassfurtite
or both mixed with hydraulic magnesia or the latter alone.
To whichever of these different bodies I select I add pulverised crystallin
carbonate of lime (calc-spar) in order to impart to it a great solidity and at the
same time to render it waterproof and capable of resisting the influence of the
weather.
The dry mixture thus obtained is brought into an equeous solution of chlorides
such as chloride of zinc, chloride of aluminium ammonian chloride, common salt
and the like.
As a filling mass I employ finely levigated paper fibre after preparing it in
the following manner. The still moist paper fibre I mix with a very small quantity
of one or more of the above named chlorides of the carbonate of lime (calc-spar)
and the magnesite, boracite or stassfurtite, and then let the paper fibre thus
prepared dry, whereupon I grind it finely with suitable appliances.
Improvements in Artificial Stone.
I, FRITZ GENRE. Civil Engineer, of 117, Mainzer Chaussee, Coblenz, in the
Kingdom of Prussia, Empire of 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:--
It is known that magnesia cements made of magnesite and chlorides such as
chloride of magnesium and chloride of aluminium, have the disadvantage of

page_text: being neither waterproof nor water resisting, nor are they capable of resisting the
frost and the influence of the weather.
To obviate this defect I employ instead of magnesite, bodies which, when
mixed with chlorides, do not possess these disadvantages. Such bodies are
boracite or strassfurtite or borate of magnesia or their respective residues left after
the chemical separation of the boron, either each body alone or two or more
of them mixed together, or I may employ boracite, or strassfurtite or borate of
magnesia or their residues left after the chemical separation of the boron, either
singly or two or more of them mixed with hydraulic magnesia, or finally the
latter alone.
To whichever of these different bodies I select I add 15 to 25 per cent. of
pulverised carbonate of lime (cale spar) in a crystalline or compact state, in order
to impart to it a high degree of solidity and at the same time to render it perfectly
waterproof and capable of resisting the influence of the weather.
Hitherto, carbonate of lime has also been employed for the preparation of
different artificial stone mixtures, but only as filling material in combination with
magnesite but a technical effect cannot possibly be obtained when carbonate
of lime is used merely as filling material for magnesite only since, the carbonic
acid contained therein causes blisters, or cracking on the surfaces covered with
it or on the article made out of it, while I find from my practical experiences and
trials that the carbonate of lime, in the combination I claim, with the bodies
mentioned above, does not show these disadvantages.
The dry mixture obtained in the manner described above is brought into an
aqueous solution of chlorides, as for example, chloride of zinc, chloride of alumina,
chloride of ammonium, chloride of magnesium or the like, each of them being
either used alone or more of them mixed together.
The proportions depend on the qualities of the raw material and the purposes
they are to serve, and vary between 30 and 45 per cent.
As filling material for the mixture thus obtained I use 10 per cent. of paper
fibre, after preparing the same in the following peculiar manner.
The paper fibre, being still in a moist, but finely elutriated state, is mixed with
a very small portion of the mixture of boracite or stassfurtite, or borate of
magnesia, or the residues of these bodies left after the chemical separation of
the boron, with one or more of the said chlorides and with carbonate of lime,
the mixture so obtained being then left to harden.
After the complete hardening, the product is reduced to powder by mechanical
means in order to render it suitable as filling material in the manner described.
This process in the preparation of the paper fibre is necessary for the reason
that the paper fibre, when added in a moist state, will form lumps which would
produce uneven and soft places in the product obtained. In order to give the
latter a marble-like or any other appearance, the filling material, the paper fibre,
may be coloured.
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) In an improved artificial stone the combination of one or more chlorides
such as those of zinc, alumina, ammonium, magnesium and the like, with boracite
or stassfurtite, or borate of magnesia or residues of these bodies left after the chemical
separation of the boron each body being separate or mixed with the other
substantially as described.
(2) In an improved artificial stone the combination of the chlorides specified in
Claim 1, with boracite or stassfurtite or borate of magnesia or the residues of these
bodies left after the chemical separation of the boron, either singly or two or more
of them mixed with hydraulic magnesia or with the latter alone.
and with

page_text: pulverized or compact carbonate of lime and chemically prepared paper fibre
reduced to powder to serve as a filling material substantially as described.
Dated this 7th day of April 1899.
J. B. FLEURET,
5, Hatton Garden, London, E.C., Agent for the Applicant.