AN IMPROVED PROCESS FOR SEPARATING TIN FROM TINNED PLATES AND OTHER TINNED ARTICLES
Year: 1878

page_text: LETTERS PATENT to Berenth Siegler, of Fenchurch Street, in the County of
Middlesex, for the Invention of "AN IMPROVED PROCESS FOR SEPARATING TIN
FROM TINNED PLATES AND OTHER TINNED ARTICLES."
PROVISIONAL SPECIFICATION left by the said Berenth Siegler at the Office
of the Commissioners of Patents on the 17th July 1878.
BERENTH SIEGLER, of Fenchurch Street, in the County of Middlesex.
"AN
IMPROVED PROCESS FOR SEPARATING TIN FROM TINNED PLATES AND OTHER
TINNED ARTICLES."
My Invention has for its object an improved process for separating and utilizing
the metallic tin from the surface of tinned iron or other plate, tin plate scraps, or
other articles or pieces of tinned plate.
By my improved process the metallic tin is obtained and utilized more economi-
cally than has heretofore ordinarily been the case.
I take a vessel of glass or other material capable of resisting the action of muriatic
acid, and into this vessel I place a sufficient quantity of the tinued plate or scraps
from which the tin is to be separated, and upon it I pour, sufficient ordinary muriatic
acid to cover it.
When the tin has been dissolved by the muriatic acid I draw off the latter, pre-
ferably by a cock or valve at or near the bottom of the vessel, and I pour it over a
fresh quantity of tinned plate, scraps, or cuttings in a second vessel, and so on in
succession until the acid will no longer dissolve the tin.
I then precipitate the iron which may have been dissolved together with the tin
by the addition of a sufficient quantity of prussiate of potash. The precipitate
or sediment thus formed is Prussian blue, which may be collected and utilized, or
sold.
The clear liquid remaining is used for the purpose of dissolving a further
quantity of tin from tinned plate, cuttings, or scraps, and in order to enable it so

page_text: to act I place at the bottom of the vessel a sufficient quantity of sulphuret or other
ore of copper, and I then fill the vessel with the tinned plate fragments and pour
the liquid over them.
By this means I dissolve the tin and obtain the copper from the ore, and this
process I repeat a sufficient number of times, preferably fifteen to eighteen, and the
liquid then becomes incapable of further action.
I then decompose the liquid by the addition of sufficient prussiate of potash to
precipitate all the iron as Prussian blue, after which I add a sufficient quantity of
solution of carbonate of potash, which precipitates the tin in the form of oxide
of tin, which I dissolve in sulphuric acid, so as to obtain a solution of sulphate of
tin which may be utilized, or from which the tin may be extracted in the ordinary
way in the form of tin sponge, which may be melted and used as metallic tin.
The iron plate or scraps from which the tin has been removed in the way described
may be used in the well-known-way for precipitating copper from a solution; or it
may be used by ironworkers, and the copper, precipitated as above described, may
be melted into blocks or ingots of metallic copper; or it may be oxidized and used
in the manufacture of paint.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Berenth Siegler in the Great Seal Patent Office on the 17th January
1879.
BERENTH SIEGLER, of Fenchurch Street, in the County of Middlesex.
" AN
IMPROVED PROCESS FOR SEPARATING TIN FROM TINNED PLATES AND OTHER
ARTICLES."
This Invention has for its object an improved process for separating and utilizing
metallic tin from the surface of tinned iron or other plate, scraps and waste pieces of
tin plates, and other articles or pieces of tinned plates.
By my improved process, herein-after described, the inetallic tin upon such scraps
or pieces of tinned plates is separated and utilized, or made marketable, more.
economically and with less waste of the materials employed than has heretofore
been the case in processes for a similar purpose.
In order to carry out my Invention I take a vessel or tank of sufficient size made
of earthenware, glass, or other material capable of resisting the action of muriatic
acid or such other acid as I may employ, and into it I place the acid required for
the operation, and into these vessels or tanks containing the acid I place a certain
quantity of tinned iron or tinned plates sufficient to fill the said vessels or tanks,
-always-however allowing the acid to cover the tinned iron or plates; or if smaller
quantities are used it may be advisable to use smaller vessels, and to put the tinned
iron or tinned articles into them, and to pour in the acid until the said tinned
articles are covered.
The tin is attacked by the acid, and when the former has been sufficiently dis-
solved it is taken out and another quantity of tinned iron or tinned articles is put
into the vessel or tank, and I continue to repeat the process until the acid is so
saturated as to require a considerable time to dissolve the tin from the tinned
plates.
As soon as this stage of the process has been reached, I transfer the acid into
another vessel or tank (or I allow it to remain in the same tank), and I then pro-
ceed to renew the acid by heating it by means of steam or other convenient means,
which enables the acid to dissolve a further quantity of tin from tinned plate which
has been put into the vessel or tank containing the heated acid. As soon as the tin
is dissolved, the iron scraps or cuttings remaining are taken out, and a new
quantity is placed into the vessel or tank, and I continue to repeat the process
until the acid is so weakened as to be unable to dissolve more of the tin from the
tinned plates.
Either after having transferred the acid to a fresh vessel, or in the same tank, I
place on the bottom of the vessel or tank a small quantity of copper ore, thereby
enabling the acid to dissolve a further quantity of tin.
Before putting the copper ore into the vessel or tank I add a small quantity of
prussiate of potash, with or without the addition of a small quantity of liquid
ammonia.
By this process I obtain a more saturated solution of muriate of tin. Metallic
copper is also precipitated.
To utilize the muriate of tin obtained as described I proceed as follows:-I take
the solution and I decompose it by the addition of a sufficient quantity of prussiate
of potash (preferably with the addition of a small quantity of liquid ammonia),
which precipitates all the iron in the solution in the form of Prussian blue, and I
afterwards add a sufficient quantity of a solution of carbonate of potash, which pre-
cipitates the tin from the solution in the form of oxide of tin; this oxide of tin is
then dissolved in sulphuric acid, so as to bring the tin to the condition of a sulphate
which may be utilized, or from which the tin may be extracted in the ordinary way
by precipitation by means of metallic zinc or otherwise, so as to form tin sponge,
which may be melted down into ingots and utilized or sold.

page_text: Or I at once precipitate the tin by means of metallic zinc, whereby tin sponge is
formed, which can be either melted into ingots or sold in that state. The remainder
is chloride of zinc, to which I add ammoniacal liquor, producing thereby sal
ammoniac and oxide of zinc; I add sulphuric acid to the oxide of zinc, producing
sulphate of zinc, a marketable article.
Or I proceed to add to the solution of muriate of tin ammoniacal liquor, which
precipitates the tin from the solution in the form of oxide of tin; this oxide of tin
is then dissolved in sulphuric acid, so as to bring the tin to the condition of a
sulphate which may be utilized, or from which the tin may be extracted in the
ordinary way by precipitation by means of metallic zinc. or otherwise, so as to form
tin sponge, which may be melted down into ingots, as already described.
When the muriatic acid is so saturated with tin that it will not dissolve any
more tin from the tin cuttings, I sometimes employ a galvanic battery to renew the
strength of the said acid, and I put fresh quantities of tin cuttings into the vessel
or tank as long as the acid will act. At the same time the action of the galvanic
battery will precipitate the tin held in solution by the acid into crystallized tin, and
the remainder of the solution I utilize in the way already described.
The iron scraps or fragments remaining, from which the tin has been removed in
the way described, may be used in the ordinary well-known way for the purpose of
precipitating copper from a solution, or it may be used to be worked up into iron in
the usual way.
The metallic copper precipitated in the way described may be melted into blocks
or ingots, or it may be oxidised and used in the manufacture of paint.
I do not claim the precise relative proportion or strength of the different materials
used in the improved process as above described, as they may be varied more or less
to suit varying circumstances, but,-
Having now described my Invention, and the manner in which it is to be per-
formed, I claim,―
The method of separating and utilizing tin from tin cuttings and other tinned
articles by submitting them to the action of muriatic acid in the first instance, as
commercially produced, and afterwards by heating the same and adding copper ore,
or by using a galvanic battery, substantially as described.
Also, the method of separating the iron from the solution by means of prussiate of
potash, and precipitating the tin by means of carbonate of potash, substantially as
and for the purpose described.
い
... In witness whereof, I, the said Berenth Siegler, have hereunto set my hand
and seal, this Seventeenth day of January, in the year of our Lord One
thousand eight hundred and seventy-nine.
BERENTH SIEGLER. (L.S.)