Improvements in the Production of Artificial Stone.
Year: 1896

page_text: Date of Application, 20th Apr., 1896
Complete Specification Left, 29th Aug., 1896-Accepted, 17th Oct., 1898
PROVISIONAL SPECIFICATION.
Improvements in the Production of Artificial Stone.
I, LUDWIG PREUSSNER, Chemist, of Passauorstrasse 39, Berlin, in the Empire of
Germany, do hereby declare the nature of this invention to be as follows:-
Artificial stone produced of basic chlorhydrate of magnesium and appropriate filling
masses show several considerable inconveniences which hinder their use. Those
inconveniences are especially sweating, expansion and splitting which are found in
all such products and, as it seems, especially when the magnesia or other ingredient
used contains large masses of liue which react with the chloride of magnesium after
some time and is transformed into deliquescent chloride of calcium.
As an important means for avoiding these inconveniences and as an essential
improvement in all artificial stone produced of basic or lime containing chlorhydrate
of magnesium, I have used as an addition with complete success acid phosphate of
lime or phosphoric acid.
Artificial stone produced according to this process and objects made therefrom
become, by the said addition, stable in volume, show no expansion or contraction or
transpiration, are of astonishing hardness, of pure marble white colour, nearly
impermeable against water, take a high polish and preserve the polish unvaried for a
long time.
In practising my process I produce from hydrochloric acid and burnt magnesia a
strongly basic chloride of magnesium, which I mix with convenient ingredients
according to the objects to be produced and to which I then add acid phosphate of
lime soluble in water. The soluble acid phosphate of lime enters at once, with the
magnesia or the other ingredients as alumina, lime, iron etc. into insoluble combinations,
by which the bodies produced are of the hardness of apatite, and the formation of
chloride of calcium soluble in water is hindered.
For the purpose of the production I mix in a sufficiently large enamelled vessel
of stone-ware or porcelain 1000 gr. crude hydrochloric acid of 22° B. with
500-1000 gr. water and 4000-6000 gr. burnt magnesia. This mixture is well mixed
by stirring it with a porcelain or wooden bar and according to necessity an equal
part or more of filling masses are added: it is then again well stirred and there is
added simultaneously the solution of acid phosphate of lime in the proportion of one
quartor to one half of the amount of hydrochloric acid that has been used. If
necessary I pass the whole mass through a suitable sieve and pass it into forms where
it soon bocoines set and stone-hard, only a little polishing or dressing being necessary
before use.
The acid phosphate of lime (CaH,P,O, + H,O) is made by dissolving 100 parts
of tri-basic phosphate of lime (Ca,P,O with 63'1 parts of sulphuric acid hydrate
and 29 parts of water and decantation and concentration of the solution.
In its place may also be used the hydrate of phosphoric acid in rough state free of
lime (HP,O,) which is mudo by mixing 100 parts of tri-basic phosphate of lime
with 94-6 parts of sulphuric acid hydrate and 34-8 parts of water, decanting and
concentrating. In this case, of the hydrate of phosphoric acid there is taken two
thirds of the weight of the above named acid phosphate of lime and the same procèss
is followed.
Instead of hydrochloric acid and magnesia, I may also use pure chloride of
magnesium with burnt magnesia in equal parts, and then up to one quarter of the
weight of chloride of magnesium used I add acid, phosphate of lime dissolved in

page_text: As the fresh burnt magnesia absorbs carbonic acid very quickly from the air
up to the half of its weight, as well as water, this quality of the magnesia has to
be considered in fixing the proportions of the mixture.
The analysis of the stone binding substance existing in the beforementioned
combinations resulted in 394 parts.
According to the composition of the magnesia used the analysis will show more or
less variation especially after the adding of the corresponding filling masses. An
exactly limited chemical formula cannot be given or observed.
As filling masses I use sand, quartz, flint, fluor spar, marble, barytes as well as
snitable mineral colours and when necessary, organic substances such as sawdust,
cellulose etc. and in the production of whet-stones I use emery, corundum, carborundum
or any artificial and natural whetting means. In this uanner the most diverse
objects may be produced for use as artificial stone or marble in architecture, building
and other trades, as well as for replacing ceramic products by means of their
resistance, beauty and cheapness; the process is also especially suitable for producing
whot-stones.
Dated this 20th day of April 1896
HERBERT HADDAN & Co.,
Agents to the Applicant.
Improvements in the Production of Artificial Stone.
I, LUDWIG PREUSSNEB, of Passauerstrasse 39, Berlin, in the Empire of Germany,
Cheinist, 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 :-
Artificial stone produced of basic chlor-hydrate of magnesium and appropriate
filling masses show several considerable inconveniences, which hinder their use.
These inconveniences are especially sweating, expansion and splitting which are
found in all such products and, as it seems especially when the magnesia or other
ingredient used contains large masses of lime which reacts with the chloride of
magnesium after some time and is transformed into deliquescent chloride of calcium.
As an important means for avoiding those inconveniences and as an essential
improvement in all artificial stone produced of basic or lime containing chlor-hydrate
of magnesium I have usod as an addition with complete success acid phosphate of
lime or phosphoric acid.
Artificial stone produced according to this process and objects made therefrom
become by the said addition stable in volume show no expansion or contraction or
transpiration are of astonishing hardness of pure marble-white colour nearly
impermeable against water take a high polish and preserve the polish unvaried for a
long time.
In practising my process I produce from hydrochloric acid and burnt magnesia a
strongly basic chloride of magnesium which I mix with convenient ingredients
according to the objects to be produced and to which I then add acid phosphate of

page_text: lime soluble in water. The soluble acid phosphate of lime enters at once with the
magnesia or the other ingredients as aluminia, lime, iron etc. into insoluble com-
binations, by which the bodies produced aro of the hardness of apatito and formation
of chloride of calcium soluble in water is hindered.
For the purpose of the production I mix in a sufficiently large enamelled vessel of
stone ware or porcelain 1,000 gr. crude hydrochloric acid of 22 degrees B. with
500 to 1,000 g. water and 4,000 to 6,000 g. burnt magnesia. This mixture is well
mixed by stirring it with a porcelain or wooden bar and according to necessity, an
equal part or more of filling masses are added; it is then again well stirred and there
is added simultaneously the solution of acid phosphate of lime in the proportion
of to one half of the amount of hydrochloric acid that has been used. If necessary
I pass the whole mass through a suitable sieve and pass it into forms, where it soon
becomes set and stone hard only a little polishing or dressing being necessary
before use.
The acid phosphate of lime (CaH,P,O, + H,O) is made by dissolving 100 parts of
tri-basic phosphate of lime Ca,P,O, with 631 parts of sulphuric acid hydrate and
29 parts of water and decantation and concentration of the solution.
In its place may also be used the hydrate of phosphoric acid in rough state free of
lime H,P,O, which is made by mixing 100 parts of tri basic phosphate of lime
with 946 parts of sulphuric acid hydrate and 34-8 parts of water decanting and
concentrating. In this case of the hydrate of phosphoric acid there is taken of
the weight of the above named acid phosphate of lime and the same process is
followed.
Instead of hydrochloric acid and inagnesia I may also use pure chloride of
magnesium with burnt magnesia in equal parts and then up to of the weight of the
chloride of magnesium used I add acid, phosphate of lime dissolved in water. As
the fresh burnt magnesia absorbs carbonic acid very quickly from the air up to the
half of its weight, as well as water, this quality of the magnesia has to be considered
in fixing the proportions of the mixture.
The analysis of the stone forming binding substance existing in the before mentioned
combinations resulted in 894 parts.
According to the composition of the magnesia used the analysis will show more or
less variation especially after the adding of the corresponding filling masses. An
exactly limited chemical formula cannot be given or observed.
As filling masses I used sand quartz, flint, fluor-spar, marble barytes as well as
suitable mineral colours and when necessary organic substances such as saw-dust
cellulose etc. and in the production of whetstones I add omery corundum, carborundum
or any artificial and natural whetting means.
In this manner the most diverse objects may be produced for use as artifical stone
or marble in architecture building and other trades as well as for replacing ceramio
products by means of their resistance, beauty and cheapness the process is also
especially suitable for producing whetstones.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is.
The process of producing artificial stone especially whet-stones by using acid

page_text: phosphate of lime or hydrate of phosphoric acid, in combination with natural or
artificial chloride of magnesium adding burnt magnesia and convenient filling masses
substantially as set forth.
Dated this 29th dex of August 1896.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, W.O., Agents for Applicant.