Improvements in the Art, Method, or Process of Treating Gypsum Rock for the Production of Artificial Marble and the like.
Year: 1897

page_text: Date of Application, 25th Mar., 1897
Complete Specification Left, 14th Jan., 1898--Accepted, 19th Feb., 1898
Improvements in the Art, Method, or Process of Treating Gypsum
Rock for the Production of Artificial Marble and the like.
I, THOMAS PARKER, of Copeley Hill, Gravelly Hill, Erdington, in the County
of Warwick, Mechanical Engineer, a communication from George Washington
Parker, of Detroit, Michigan, United States America, do hereby declare the nature
of this invention to be as follows:-
a
This invention relates to the treatment of gypsum rock for the purpose of
producing a hard and durable product capable of receiving high polish, and to
serve as a substitute for marble or the different varieties of chalcedony, such as
onyx, agate and like substances both in plain white or grey, and wholly or partly
in colours as may be desired.
The essential feature of my invention is the treatment of gypsum rock by dehy-
dration, and chemical immersion whereby the same may be made to imitate marble
and the like and the improvement has for its special object to facilitate and hasten
crystallization, obviate all danger of the rock slacking and cracking during treat-
ment, as well as to produce a better and more desirable product than has resulted
from other methods employed by me or others.
Prior to treatment by my art, method or process the native gypsum rock as taken
crude from the mine, is sawn, and shaped by planing and turning into the desired
configuration.
It must be understood that all kinds of trimming to serve in place of wood work,
and such fancy articles as pillars, knobs, brackets and other configurated blocks
and ornaments, are contemplated to be produced in carrying out my process, and
therefore need not be further alluded to.
The first step in the process is to dehydrate the native rock (after it has been
shaped into the desired form) by the action of hot air applied at a temperature of
approximately 330 degrees Fahrenheit, for twelve hours, more or less, or until the
element of moisture in the native rock is eliminated.
A convenient plan is to load the formed articles on to a truck, running on a track,
into the hot air compartment where it is allowed to remain until the moisture has
been eliminated and the rock thus reduced to calcium, in a porous condition.
.
Cooling the rock is the next step in the process. It has been my practice prior
to the present invention to cool the hot dehydrated rock by letting it remain for
some time in the open air. I have found, however, that by this plan the rock is
iable to slack, more or less, and also crack, and what is further very objectionable,
t becomes impregnated with moisture which it takes from the atmosphere, thus
undoing to a considerable degree the work already accomplished, and retarding and
liminishing crystallization in the after treatment.
To overcome these difficulties, the design of my present invention is to effect
Cooling of the block in a compartment from which the outer air is excluded, and
his compartment I charge with gas or fumes of ammonia during the time the rock
emains therein.

page_text: The effect of this mode of cooling is to render the rock sooner fit for subjection
to the next treatment, and as there is no slacking or cracking of the article such
next treatment is consequently more effectual in every way.
A convenient plan for using the ammonia for this purpose will be found in
placing a tank or barrel containing aqua-ammonia underneath the cooling compart-
ment, and conducting the fumes of ammonia through suitable perforated pipes
or conduits located say between the rails of the track upon which the cars carrying
the articles under treatment run.
The cooling compartment is preferably located some distance away from where
the other work is performed so that the attendants will not be exposed to the fumes
which are allowed to escape before the rock is removed for further treatment.
There is not, however, enough ammonia required to be used with any one batch of
rock to unduly charge the open air as it escapes.
While the rock is cooling as above, a bath composed of a solution of aluminium
sulphate is prepared and heated to approximately 100 degrees Fahrenheit. Directly
the rock is cool, I immerse it in this warm solution for a short time, or until the
pores are filled.
My object in warming, the solution is to prevent the bursting out of particles
of the rock (an object which I have found in my experience to arise from the use of
a cold bath of this solution) and to improve and accelerate the crystallization, which
I find takes place immediately in the warm bath.
After having been treated as above the rock is allowed to dry. It is then
susceptible of receiving high polish, and this presents a hard surface of beautiful
lustre, which cannot be effected by frost or any other atmospheric changes. I have
found that it is not even susceptible to the action of muriatic acid.
When it is desired to produce colour effects in the imitation of fancy marbles,
onyx, agate and the like, after the gypsum rock has been dehydrated, and thus
reduced to calcium, sulphate and porous throughout, any desired mineral colours
may now be applied to the surface of the dehydrated material, such as, for illustra-
tion, a solution of copper nitrate of aqua-ammonia, or a solution of sulphate of iron,
nitric acid and potassium, sulpho-cyanide, or other combinations of colouring
elements known to chemists. After being thus coloured the material is immersed
in the aluminium sulphate solution until the pores are completely filled as already
described.
I wish it to be understood that I do not limit myself to the precise details above
described as suitable for carrying out my invention, as the same may be modified
or varied, according to judgment and different circumstances without departing
from the principle, or sacrificing the advantages of my invention.
1
1 1902
ALFRED WILLIAM TURNER,
Cobden Buildings, 67, Corporation Street, Birmingham,
Agent for the Applicant.
Improvements in the Art, Method, or Process of Treating Gypsum
Rock for the Production of Artificial Marble and the like.
I, THOMAS PARKER, of Copeley Hill, Gravelly Hill, Erdington, in the County
of Warwick, Mechanical Engineer, do hereby declare the nature of this invention.
and in what manner the same is to be performed, to be paticularly described and
ascertained in and by the following statement:-
This invention relates to the treatment of gypsum rock for the purpose of produc-
ing a hard and durable product, capable of receiving a high polish, and to serve as

page_text: a.substitute for marble or the different varieties of chalcedony, such as onyx, agate
and like substances, both in plain white or grey, and wholly or partly in colors
as may be desired.
The essential feature of my invention is the treatment of gypsum rock by dehy-
dration and chemical immersion whereby the same may be made to imitate marble
and the like and the improvement has for its special object to facilitate and hasten
crystallization, obviate all danger of the rock slacking and cracking during treat-
ment, as well as to produce a better and more desirable product than has resulted
from other methods employed by me or others.
Prior to treatment by my art method or process, the native gypsum rock as
taken crude from the mine, is sawn and shaped by planing and turning into the
desired configurations.
It must be understood that all kinds of trimming to serve in place of wood work,
and such fancy articles as pillars, knobs brackets and other configurated blocks
and ornaments, are contemplated to be produced in carrying out my process, and
therefore need not be further alluded to.
:
The first step in the process is to dehydrate the native rock (after it has been
shaped into the desired form) by the action of hot air applied at a temperature of
approximately 330 degrees Fahrenheit, for twelve hours, more or less or until the
element of moisture in the native rock is eliminated.
A convenient plan is to load the formed articles on to a truck, running on a track,
into the hot air compartment where it is allowed to remain until the moisture
has been eliminated and the rock thus reduced to calcium sulphate, in a porous
condition.
Cooling of the rock is the next step in the process. It has been my practice
prior to the present invention to cool the hot dehydrated rock by letting it remain
for some time in the open air. I have found, however, that by this plan the rock
is liable to slack, more or less, and also crack, and what is further very objection-
able, it becomes impregnated with moisture which it takes from the atmosphere,
thus undoing to a considerable degree the work already accomplished, and retard-
ing and diminishing crystallization in the after treatment.
To overcome these difficulties, the design of my present invention is to effect the
cooling of the block in a compartment from which the outer air is excluded, and
this conipartment I charge with the gas or fumes of ammonia during the time the
rock remains therein.
The effect of this mode of cooling is to render the rock sooner fit for subjection
to the next treatment, and as there is no slacking or cracking of the article such
next treatment is consequently more effectual in every way.
A convenient plan for using the ammonia for this purpose will be found in plac-
ing a tank or barrel containing aqua-ammonia underneath the cooling compartment,
and conducting the fumes of ammonia through suitable perforated pipes to
conduits located say between the rails of the track upon which the cars carrying
the articles under treatment run.
The cooling compartment is preferably located some distance away from where
the other work is performed, so that the attendants will not be exposed to the fumes
which are allowed to escape before the rock is removed for further treatment. There
is not however, enough ammonia required to be used with any one batch of rock
to unduly charge the open air as it escapes.
While the rock is cooling as above, a bath composed of a concentrated solution
of aluminium sulphate is prepared and heated to approximately 100 degrees
Fahrenheit. Directly the rock is cool I immerse it in this warm solution for a
short time or until the pores are filled.
My object in warming the solution is to prevent the bursting out of particles of
the rock (an objection which I have found in my experience to arise from the use
of a cold bath of this solution) and to improve and accelerate the crystallization,
which I find takes place immediately in the warm bath.

page_text: After having been treated as above the rock is allowed to dry. It is then
susceptible of receiving high polish, and this presents a hard surface of beautiful
lustre, which cannot be affected by frost or any other atmospheric changes. I have
found that it is not even susceptible to the action of muriatic acid.
When it is desired to produce color effects in the imitation of fancy marbles, onyx,
agate and the like, after the gypsum rock has been dehydrated, and thus reduced to
calcium sulphate and porous throughout, any desired mineral colors may now be
applied to the surface of the dehydrated material, such as, for illustration, a solu-
tion of copper nitrate of aqua-ammonia, or a solution of sulphate of iron, nitric
acid and potassium sulpho-cyanide, or other combinations of coloring elements
known to chemists. After being thus colored the material is immersed in the
aluminium sulphate solution until the pores are completely filled as already
described.
I wish it to be understood that I do not limit myself to the precise details above
described as suitable for carrying out my invention, as the same may be modified
or varied, according to the judgment and different circumstance without departing
from the principle, or sacrificing the advantages of my invention.
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:
-
1. The art, method, or process of treating native gypsum rock which consists
essentially in eliminating the moisture from the rock by the action of hot air,
then removing the resultant hot calcium sulphate into a closed compartment charged
with fumes of ammonia, and then immediately subjecting the cool rock to immer-
sion in a warm solution of aluminium sulphate until the pores are filled, substan-
tially as and for the purpose set forth.
2. The art, method or process of treating native gypsum rock which consists
essentially in eliminating the moisture from the rock by the action of hot air,
then applying any desired coloring element and cooling the resultant colored
calcium sulphate in a closed compartment charged with the fumes of ammonia,
and then subjecting the cool rock to immersion in a warm solution of aluminium
sulphate until the pores are filled, substantially as and for the purpose set forth.
Dated this 12th day of January 1898.
CHARLES BOSWORTH KETLEY.
Agent for the Applicant.