IMPROVEMENTS IN THE MANUFACTURE STANNATE OF SODA AND. STANNATE OF POTASH
Year: 1871

page_text: LETTERS PATENT to Edward Primerose Howard Vaughan, F.O.S., of
OR
54, Chancery Lane, in the County of Middlesex, Patent Agent,
for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
STANNATE OF SODA AND. STANNATE OF POTASH."-A communication from
abroad by Charles Lennig, of the Oity of Philadelphia, in the
State of Pennsylvania, in the United States of America.
PROVISIONAL SPECIFICATION left by the said Edward Primerose
Howard Vaughan at the Office of the Commissioners of Patents,
with his Petition, on the 29th August 1871.
I, EDWARD PRIMEROSE HOWARD VAUGHAN, F.C.S., of 54, Chancery
Lane, in the County of Middlesex, Patent Agent, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF STANNATE OF SODA AND STANNATE OF POTASH," being a communication to
me from abroad by Charles Lennig, of the City of Philadelphia, in the

page_text: State of Pennsylvania, in the United States of America, to be as
follows:-
This Invention relates to certain improvements in the manufacture of
stannate of soda and stannate of potash by the alternate employment
and action of caustic alkalies and of atmospheric air upon tin, or tinned ||
surfaces, as described hereafter.
When it is desired for the purposes of this Invention to employ tin
capable of being obtained from tin plated metals, such as tinned iron or
copper, and especially clippings or waste of the same, the clippings or
tin coated metals are placed in a vessel constructed of wrought or cast 1
iron, or of any other material adapted for the purpose, as will be well
understood, and of such form and capacity as may be considered desirable.
This vessel is provided with a valve or stop-cock placed so as to permit
of the free discharge of liquid therefrom when desired. One or more
pipes (preferably constructed of iron) is or are connected with an air ]
pump or ventilator, and in communication with the said vessel in such a
way as to allow a current of air to be driven through the clippings
when required. A solution of caustic soda or potash of about 1,200°
specific gravity is poured into the said vessel, and over the tinned
surfaces or clippings to be treated by the aid of a pump, air elevator, 2
monte-jus, or other suitable means, so as to drench the tin surfaces
thoroughly, which being done the liquor is drawn off into a cistern or
reservoir, and currents of air are driven through the clippings for a few
minutes by aid of the pipes and ventilator above named. The previously
drawn off caustic liquid is thereupon again pumped over the clippings, 2
and this alternating process of passing air through, drenching, and
redrenching the clippings with the same liquid is continued until the
tin has been entirely removed from the metal upon which it has been
deposited.
The process may be materially accelerated by warming the liquid and 3
the air. The first charge of clippings is then removed, and a fresh one
substituted, and so on so long as tin is dissolved or removed; and when
the action ceases a fresh portion of caustic alkali is employed. The
saturated solution has thus been mostly converted into stannate of soda
or stannate of potash by the action of the oxygen of the atmospheric 3
air in contact with the moist caustic alkali and tin. By evaporating
this saturated solution in iron or other vessels as long as a sedimentary
salt separates therefrom, and raking or scooping the latter out from the

page_text: liquid as it is formed, and placing it on a proper separator or drainer,
stannate of soda or potash is obtained in a fit state for use or sale after
being slightly washed with water. The residuary liquid which deposits
no more or very little salt by evaporation may be diluted with water
to about 1,200° specific gravity, and again used as above mentioned.
If it is desired to recover the tin in a metallic fórm' the stannate
obtained as above mentioned is dried and mixed perfectly with 15 to 20
per cent. of finely powdered coal in a crucible or proper reverberatory
furnace, and subjected to such a temperature as will reduce the tin in
the alkaline stannate to metal to be cast into bars or ingots. This
process is not, however, claimed as being part of the present Invention.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward Primerose Howard Vaughan in the Great
Seal Patent Office on the 26th February 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
PRIMEROSE HOWARD VAUGHAN, F.C.S., of 54, Chancery Lane, in the
County of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of August, in tho
year of our Lord One thousand eight hundred and seventy-one, in thỏ
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors}
give and grant unto me, the said Edward Primerose Howard Vaughan;
Her special licence that I, the said Edward Primerose Howard Vaughan;
my executors, administrators, and assigns, or such others as I, the said
Edward Primerose Howard Vaughan, 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 MANUFACTURE
OF STANNATE OF SODA AND STANNATE OF POTASE,” being a communication to
me from abroad by Charles Lennig, of the City of Philadelphia, in the
State of Pennsylvania, in the United States of America, upon the
condition (amongst others) that I, the said Edward Primerose Howard

page_text: Vaughan, 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 5
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Edward Primeroso Howard Vaughan, .
do hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :—
This Invention relates to certain improvements in the manufacture of
stannate of soda and stannate of potash by the alternate employment
and action of caustic alkalies, and atmospheric air upon tin or tinned
metallic surfaces, as herein-after described.
When it is desired for the purposes of this Invention to employ tin 1
capable of being obtained from tin plated metal, such as tinned iron or
copper, and especially clippings or waste of such materials, the clippings
or tin plated metals are placed in a vessel constructed of wrought or
cast iron, or of any other material adapted for the purpose, as will bo
well understood, and of such form and capacity as may be considered 2
desirable. This vessel is provided with a valve or stop-cock placed so
as to permit of the free discharge of liquid therefrom when desired.
One or more pipe or pipes (preferably constructed of iron) is or are
connected with an air pump or ventilator, the same being in commu-
nication with the interior of the said vessel in such a way as to allow a 2
current of air to be driven through the clippings or materials contained
therein when required. A solution of caustic soda or caustic potash
(according to the nature of the stannate which it is desired to obtain)
of about 1,200 specific gravity is poured into the said vessel, and over
the tinned surfaces or clippings to be treated, such operation being a
performed by the aid of a pump, air clevator, monte-jus, or other
suitable means, so as thoroughly to drench the tinned surfaces. This
object being effected the liquor is drawn off into a cistern or reservoir,
and currents of air are driven through the clippings, or over the tinned
surfaces by aid of the pipe or pipes and appliances before referred to.
The caustic liquid previously drawn off is then again pumped over the
clippings, and this alternating process of passing air through and

page_text: drenching and redrenching the clippings or tinned surfaces with the
same liquid is continued until the tin has been entirely removed from
the metal upon which it had been deposited.
The process may be materially accelerated by heating the liquid and
the air. The first charge of clippings or materials is then removed,
and a fresh one substituted, and so on as long as tin is dissolved or
removed threfrom; and when action ceases a fresh portion of caustic
alkali is employed. The saturated solution thus obtained has been
mostly converted into stannate of soda or stannate of potash (as the
case may be) by the action of the oxygen of the atmospheric air in
contact with the moist caustic alkali and tin. By evaporating this
saturated solution in iron or other vessels as long as a sedimentary salt
separates therefrom, and raking or scooping or otherwise collecting such
salt from the liquid as it is formed, and placing it on a proper separator
or drainer, as will be well understood, and then slightly washing it with
water, stannate of soda or stannate of potash is obtained in a fit state for
use or for sale. The residuary liquid which deposits no more or very
little salt by evaporation may be used again after adding fresh caustic
alkali to bring it to the required strength (to about 1,200 specific
gravity), as above mentioned.
.
It will bo observed that the processes herein-before described afford a
simple and economical mode of utilising materials which would other-
wise be wasted, and of obtaining substances possessing considerablo
commercial value, and of great importanco in the manufacturing
arts.
The treatment of tin existing in a separate state and not in the
form of a coating on other metallic surfaces for the manufacture of
stannate of soda and stannate of potash, in accordance with this
Invention, is of a similar character to that before mentioned, as will be
well understood by persons conversant with chemical and metallurgical
operations, and need not be more fully described.
.
If it is desired to recover the tin in a metallic form from the stannate
of soda or stannate of potash obtained as before mentioned, the stannate
is dried and perfectly mixed with 15 to 20 per cent. of finely powdered
coal in a crucible or proper reverberatory furnace, and subjected to such
a temperature as will reduce the tin in the alkaline stannate to the
metallic state, when it may be cast into bars or ingots. This process is

page_text: not however claimed as being part of the present Invention. It
should be mentioned that the tin may be removed from tinned
surfaces in various ways, as for instance by rotating in the liquid and
air alternately, or by means of any apparatus or arrangement that will
bring air or oxygen alternately with alkaline solutions into contact with
the tinned, surfaces under treatment...
Having thus declared and ascertained the nature of the said In-
vention, and in what manner. the same is to be performed, I would
observe in conclusion that what I consider novel and original, and
therefore claim as being the Invention secured by the said herein-before 1
in part recited Letters Patent is, the manufacture of stannate of soda and
stannate of potash by the processes substantially herein-before described
and set forth, or any mere modifications thereof.
In witness whereof, I, the said Edward Primerose Howard Vaughan,
have hereunto set my hand and seal, this Twenty-sixth day of 1
February, in the year of our Lord One thousand eight hundred
and seventy-two.
E. P. H. VAUGHAN. (L.&.)