AN IMPROVED PROCESS FOR THE SEPARATION AND UTILIZATION OF THE TIN AND IRON IN TINNED IRON WASTE
Year: 1879

page_text: LETTERS PATENT to Adolph Gutensohn, of Exmouth Street, in the County
of Middlesex, Manufacturing Chemist, for the Invention of "AN IMPROVED
PROCESS FOR THE SEPARATION AND UTILIZATION OF THE TIN AND IRON IN
TINNED IRON WASTE."
Sealed the 25th May 1880, and dated the 28th November 1879.
PROVISIONAL SPECIFICATION left by the said Adolph Gutensohn at the
Office of the Commissioners of Patents on the 28th November 1879.
ADOLPH GUTENSOHN, of Exmouth Street, in the County of Middlesex, Manu-
facturing Chemist. "AN IMPROVED PROCESS FOR THE SEPARATION AND UTILIZATION
OF THE TIN AND IRON IN TINNED IRON WASTE."
My Invention relates to a combined process for the separation of the tin and
iron in tinned iron waste, and in the utilization of the samo in an economical
manner.
In a large vessel containing hydrochloric acid of ordinary commercial strength
I place tinned iron waste, which is withdrawn as the tin is removed from the
surface of the iron, and this is repeated until the solution of the tin is saturated to
such an extent that it will not remove any more tin.
I then convert the vessel into a species of galvanic battery by the immersion
in it of a porous cell containing zinc (which forms the negative pole) with some
one of the elements usually employed in chemical batteries. The positive pole
is formed by a quantity of tinned iron waste immersed in this saturated
solution.
The current thus generated I lead into a second vessel containing a similar
solution to the foregoing. I connect the positive pole of the first tank (which pole
is composed of tinned iron waste) with other tinned iron waste in this second
vessel. The negative pole of the first tank I connect to the surrounding solution
by a suitable pole presenting a considerable area.
The action in the first vessel deposits metallic tin from the solution at the same
time that the surface tin is dissolved from the tinned iron waste immersed therein,
thereby keeping the solution saturated; and this waste I replace as the tin is
removed from the surface.

page_text: In place of hydrochloric acid, as before specified, I may employ sulphuric, nitric,
or chromic acid, the action taking place in a similar manner to that described.
The residue of the tinned iron waste thus treated is metallic iron, which however
is found to retain some quantity of the tin.
This tin I remove by further immersion in a fresh solution of sulphuric or hydro-
chloric acid.
From this solution I obtain sulphate or chloride of iron (the quantity of tin salt
being almost inappreciable), and this process is assisted by the continuation through
the solution of the electrical current, the negative pole of which is formed by the
said waste, which is thus more rapidly dissolved by the acid, whilst oxide of iron is
precipitated at the other or positive pole.
The chloride or sulphate of iron I convert into hydrated per-oxide of iron in the
ordinary manner.
The iron by this last process remains in a saleable form, either metallic free from
tiu, or as hydrated per oxide, or as oxide.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Adolph Gutensohn in the Great Seal Patent Office on the 26th May
1880.
ADOLPH GUTENSON, of Exmouth Street, in the County of Middlesex, Manu-
facturing Chemist. "AN IMPROVED PROCESS FOR THE SEPARATION AND UTILIZATION
OF THE TIN AND IRON IN TINNED IRON WASTE."
My Invention relates to a combined process for the separation of the tin and
iron in tinned iron waste, and in the utilization of the same in an economical
manner.
In a large vessel containing hydrochloric acid of ordinary commercial strength
I place tinned iron waste, which is withdrawn as the tin is removed from the
surface of the iron, and this is repeated until the solution of the tin is saturated to
such an extent that it will not remove any more tin; or I may run the acid from
vessel to vessel containing tin cuttings until it is practically saturated. To the
solution thus formed I may add phosphate of soda or potash which precipitates,
and on further addition re-dissolves the tin, thus forming a solution of phosphate
of tin.
.
I then convert the vessel into a species of galvanic battery by the immersion
therein of a porous cell containing zinc (which forms the negative pole) with some
one of the elements usually employed in chemical batteries. The positive pole
is formed by a quantity of tinned iron waste immersed in this saturated
solution.
The current thus generated I lead into a second vessel containing a similar
solution to the foregoing. I connect the positive pole of the first tank (which pole
is composed of tinned iron waste) with other tinned iron waste in this second vessel

page_text: The negative pole of the first tank I connect to the surrounding solution by a
suitable pole presenting a considerable area.
The action in the first vessel deposits metallic tin from the solution at the same
time that the surface tin is dissolved from the tinned iron waste immersed therein,
thereby keeping the solution saturated, and this waste I replace as the tin is
removed from the surface.
In place of hydrochloric acid, as before specified, I may employ sulphuric, nitric,
or chromic acid, the action taking place in a similar manner to that described.
The residue of the tinned iron waste thus treated is metallic iron, which however
is found to retain some quantity of the tin.
This tin I remove by further immersion in a fresh solution of sulphuric or hydro-
chloric acid.
From this solution I obtain sulphate or chloride of iron (the quantity of tin salt
being almost inappreciable), and this process is assisted by the continuation through
the solution of the electrical current, the negative pole of which is formed by the
said waste, which is thus more rapidly dissolved by the acid, whilst oxide of iron is
precipitated at the other or positive pole, and
The chloride or sulphate of iron I convert into hydrated per-oxide of iron in the
ordinary manner.
The iron by this last process remains in a saleable form either metallic free from
tin, as hydrated per oxide, or as oxide; or where sulphuric acid has been employed
may be collected as "copperas."
.
And in order that my Invention may be the better understood, I now proceed
to more particularly describe and ascertain the manner in which it is to be
performed.
I prefer to use a series of slate tanks as vessels in which to carry out my process.
In the first of these is placed the hydrochloric acid and the tinned iron waste from
which it is desired to remove the tin. After the tin has been dissolved from the
surface of the iron, forming chloride of tin, the liquid is drawn off and delivered
into the next tank, which contains fresh tin cuttings, where a further absorption of
tin is effected. When the tin is dissolved from the waste in this second instance
the solution is transferred to a third tank, if necessary, and so on until the solution
is practically saturated with tin. I may add phosphate of soda or potash which
precipitates, and on further addition redissolves the tin, thus forming a solution of
phosphate of tin. In place of hydrochloric acid I may employ sulphuric, nitric, or
chromic acid, the process being similar.
As soon as the acid and solution of salt of tin is drawn from the respective tanks,
I add sulphuric acid to the scrap iron still remaining in them to form sulphate of
iron; this solution is again passed on from tank to tank as in the case of the
chloride until both solutions are practically saturated with tin and iron respectively.
On occasion I may prefer to use hydrochloric in place of sulphuric acid to dissolve
the iron.
I then use either a cell charged with a concentrated solution of a salt of tin, as
specified in pursuance of the conditions of my Patent, No. 3943, 1 October 1879;
or I convert one or more of the aforesaid tanks into galvanic batteries by inserting
one or more porous cells, as required, containing sulphuric acid and zinc as the
one pole, whilst the salt of tin or iron and cuttings in the tank form the other
pole.
The current of electricity thus generated is made use of in the tanks not con-
verted into batteries both to facilitate the further absorption of tin or iron from
the waste into their respective solutions, and also to redeposit the tin in a pure
crystalline condition, and to precipitate the iron either as oxide of iron or, where
the current is very strong, as spongy iron. The positive pole of the battery tank
(composed of tinned iron waste) is connected with other tinned iron waste, and the
negative pole (which is the zinc in the cell) is connected to a suitable pole presenting
a large area for the deposition of the tin. In those tanks also which have been con-

page_text: verted into galvanic batteries, as before described, the tin and iron are similarly
deposited from their respective solutions.
As free acid is still left in the salt solutions of tin and iron, even after the
additional saturating effect of the electrical current, I may recover this acid by
distillation.
The sulphate of iron which always remains by re-absorption from the cuttings in
the solution from which the oxide has been precipitated, may be prepared for com-
mercial use as crystallized copperas, or may, together with the oxide, be converted
into the peroxide of iron by heating to a red heat in iron retorts. It is evident
that I may sell the iron when stripped of the tin in its metallic condition.
And having now particularly described and ascertained the nature of my said
Invention, and in what manner it is to be performed, be it known that what I claim
as novel and desire to protect by Letters Patent is,-
The combined process for the separation and utilization of the tin and the iron
composing tinned iron waste by the application of a current of galvanic electricity
generated in a battery of which at least one element is formed by the waste
material, and solutions of salts obtained therefrom, substantially as and for the
purpose hereinbefore specified.
In witness whereof, I, the said Adolph Gutensohn, have hereunto_set
my hand and seal, this Twenty sixth day of May, in the year of our Lord
One thousand eight hundred and eighty.
In presence of
S. P. WILDING,
23, Rood Lane,
London, E.C.,
Patent Agent.
ADOLPH GUTENSOHN. (LS.)