IMPROVEMENTS IN THE PROCESS OF PREPARING KAOLIN OR CHINA CLAY AND OTHER CLAYS FOR POTTERS' USE, AND FOR EXPELLING WATER FROM OTHER EARTHY DEPOSITS
Year: 1865

page_text: LETTERS PATENT to James Wright, of St. Paul's Crescent, in the
County of Middlesex, Commission Merchant, for the Invention of
"IMPROVEMENTS IN THE PROCESS OF PREPARING KAOLIN OR CHINA CLAY AND
OTHER CLAYS FOR POTTERS' USE, AND FOR EXPELLING WATER FROM OTHER
EARTHY DEPOSITS."-A communication from abroad by Joseph Muir, of
New York City, in the United States of America.
PROVISIONAL SPECIFICATION left by the said James Wright at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
March 1865.
I, JAMES WRIGHT, of St. Paul's Crescent, in the County of Middlesex, .
Commission Merchant, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE PROCESS OF PREPARING KAOLIN OR CHINA CLAY AND OTHER
CLAYS FOR POTTERS' USE, AND FOR EXPELLING WATER PROM OTHER EARTHY DEPOSITS,"
to be as follows:-
In the preparation of kaolin or china clay and clays for potters' use it is the
practice to grind or pulverize these substances in water to allow the mica and
other extraneous matters to separate from the mixture by placing it in a vat
or other vessel and drawing off the milky pap from the vessel, leaving the
extraneous matters at the botton. The coarser substances are separated

page_text: from the mixture by passing it through fine sieves, and there remains after
these operations a milky fluid mixture, sometimes called pap, which consists
of water and very finely divided particles of clay held in suspension therein.
To this mixture is added sometimes a mixture of finely ground flint and water,
and the whole is stirred together and then suffered to run into a vat, wherein
it remains a sufficient ler gth of time to allow the finely divided materials held
in suspension in the water to subside, and the supernatant water is drawn off,
leaving the material at the bottom of the vat in a plastic state, the clay
possessing sufficient adhesiveness to hold together.
This Invention relates to the separation of the water from the milky
fluid or pap for the purpose of preparing the clay for potters' use or for the
market.
In carrying out the Invention I place the pap in a cylindrical vessel, and set
the vessel whirling at a rapid rate, and the centrifugal force communicated to
the mixture causes it to be thrown outward from the middle of the vessel and
upon the sides thereof, extending upwards (when the vessel is placed in a
vertical position) so as to coat the sides of the vessel. The finely divided
particles of clay being a little heavier than the water are thrown against the
sides of the vessel, and adhere thereto, and as the operation progresses the
coating becomes thicker and the water becomes separated, to a greater or less
extent, from the mass, depending upon the length of time the operation is
carried on. The whirling is continued until the mass adhering to the sides of
the vessel becomes condensed to the consistency required for the purpose to
which it is to be applied, and the motion being stopped the water will be
found in the middle of the vessel at the bottom, and may be drawn off there-
from by a pipe leading out of the bottom of the vessel or by a syphon. If it
is desired to dry the materials more than would be effected by carrying on
this operation at the ordinary temperature, a steam jacket may be placed
around the vessel, to which steam may be supplied through the shaft of the
whirl, which, in that case, would have to be hollow. The materials having been
brought to the desired state by the operation, they may then be removed from
the vessel in the plastic state to be used by the potter, or it may be solidified
by evaporation and prepared for market as potter's clay in the usual manner.
It will of course be understood that other earthy deposits may be separated
from the water mixed with them in the same manner and in similar
apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Wright in the Great Seal Patent Office on the 22nd
September 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
WRIGHT, of Saint Paul's Crescent, in the County of Middlesex, Commission
Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of March, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Wright, Her special licence that I, the said James Wright,
my executors, administrators, and assigns, or such others as I, the said James
Wright, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE PROCESS OF
PREPARING KAOLIN OR CHINA CLAY AND OTHER CLAYS FOR POTTERS' USE, AND FOR
EXPELLING WATER FROM OTHER EARTHY DEPOSITS," being a communication from
Joseph Muir, of New York City, in the United States of America, upon the
condition (amongst others) that I, the said James Wright, my executors or
administrators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Wright, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
In the preparation of kaolin or china clay and clays for potters' use it is the
practice to grind or pulverize these substances in water to allow the mica and
other extraneous matters to separate from the mixture placing it in a vat
5 or other vessel and drawing off the milky pap from the vessel, leaving the
extraneous matters at the bottom. The coarser substances are separated from
the mixture by passing it through fine sieves, and there remains after these
operations a milky fluid mixture, sometimes called pap, which consists of

page_text: water and very finely divided particles of clay held in suspension therein. To
this mixture is added sometimes a mixture of finely ground flint and water,
and the whole is stirred together, and then suffered to run into a vat, wherein
it remains a sufficient length of time to allow the finely divided materials held
in suspension in the water to subside, and the supernatant water is drawn off,
leaving the material at the bottom of the vat in a plastic state, the clay pos-
sessing sufficient adhesiveness to hold together when alone or mixed with the
flint powder, so as to permit the removal of the water. When the supernatant
water has been removed it has also been the practice to further dry the mass
by evaporation induced by heat.
The present Invention relates to the separation of the water from the milky
fluid or pap for the purpose of preparing the clay for potters' use or for the
market, whether the pap be composed of the clay and ground flint or clay
alone mixed with the water.
In carrying out the Invention I make use of the property of adhesiveness
of the clay and the difference of specific gravity between it and water in the
following manner :-The pap is placed in a cylindrical vessel provided with a
rotating mechanism, and the vessel is set whirling at a rapid rate, and the
centrifugal force communicated to the mixture causes it to be thrown outward
from the middle of the vessel and upon the sides thereof, extending upwards,
'(when the vessel is placed in a vertical position) so as to coat the sides of the
vessel. The finely divided particles of clay being a little heavier than the
"water are thrown against the sides of the vessel and adhere thereto, and as
the operation progresses the coating becomes thicker and the water becomes
'separated, to a greater or less extent, from the mass, depending upon the
length of time the operation is carried on. The whirling is continued until
the mass adhering to the sides of the vessel becomes condensed to the con-
'sistency required for the purpose to which it is to be applied, and the motion
being stopped the water will be found in the middle of the vessel at the
bottom, and may be drawn off therefrom by a pipe leading out of the bottom
of the vessel, or by a syphon. The sides of the whirling vessel should be
impermeable by water when the machine is in operation, otherwise the fine
particles of flint and clay will escape through the sides with the water and the
process cannot be successfully carried on, and for this reason it is impossible
to effect or assist the condensation of the pap and its separation from the
water (when the particles composing it are reduced to the proper size) by the
operation of straining without losing the finer particles of the pap, as by such
operation the coarser particles are retained and the finer escape with the
water as long as that is allowed to escape through the sides of the vessel.. If

page_text: it be desired to dry the materials more than would be effected by carrying on
this operation at the ordinary temperature, a steam jacket may be placed
around the vessel, to which steam may be supplied through the shaft of the
whirl, which in that case would have to be hollow. The materials having
been brought to the desired state by the operation just described,, the solid
matter may then be removed from the vessel in the plastic state to be used by
the potter, or it may be solidified by evaporation and prepared for market as
potters' clay in the usual manner. It will of course be understood that other
earthy deposits may be separated from the water mixed with. them in the
same manner and in similar apparatus.
In carrying out the improved process the coating of clay upon the sides of
the whirling vessel is exposed to the atmosphere under very favourable con-
ditions for evaporation, because the amount of pap or clay mixture to be placed
in the vessel to be operated upon is much less than the vessel will hold, say,
about one-third of the contents of the vessel, or less, therefore when the
vessel is set whirling rapidly the mixture is at once thrown out to the sides of
the vessel, rising up to the top, or nearly so, and the middle of the vessel is
left unoccupied and open to the atmosphere.
Fig. 1 in the accompanying Drawings is a plan view, and Fig. 2 is a
section of the whirling vessel and its rotating mechanism.
a represents the frame, and b, a vertical shaft stepped in a cross bar cat
the bottom of the frame, and provided with tight and loose pulleys d and d¹.
The upper part of the shaft runs in bearings fitted to and carries a hori-
zontal disc or platform e, upon which the whirling vesself is secured by screw
bolts g and g', or in any other convenient manner. A pipe leads from the
centre of the vessel at the bottom outward to its periphery, and is closed at
the end by a screw plug 4, or in any other convenient manner; this pipe
may be dispensed with, and in place a hole may be made in the centre of the
vessel communicating with a hole in the shaft, or a pump or syphon may be
used to draw off the water. At the top of the vessel the sides incline inwards
to prevent the material from being thrown out of the vessel and to confine it
to the sides thereof.
At Fig. 3 of the Drawing wings r (shewn by dotted lines) may be attached
to the sides. There is also shewn in Figures 4 and 5 different forms of
whirling vessels which may be used to advantage, but the forms shewn at
Figures 1 and 2 are preferred.
Having now described the Invention that has been communicated to me as
aforesaid, and having explained the manner of carrying the same into effect,
I claim as the Invention secured to me by Letters Patent as aforesaid, the

page_text: mode herein. set forth of preparing clays for potters' use, or for the market, by
subjecting the slops in proper quantities to the action of centrifugal force in a
whirling vessel, as described, whereby the clay, by reason of its adhesiveness
and greater specific gravity, is condensed and separated from the water to the
desired extent without recourse to straining, and adheres to the sides of the
vessel, from which it may be removed in a plastic state for potters' use, or to
be-prepared in the usual manner for the market as potters' clay.
In witness whereof, I, the said James Wright, have hereunto set my
hand and seal, the Twenty-second day of September, in the year of our
Lord One thousand eight hundred and sixty-five.
JAS. WRIGHT. (L.S.)