IMPROVEMENTS IN SEPARATING TIN FROM TIN PLATE SCRAP, AND TIN OR ZINC FROM. OTHER SURPACES OF IRON
Year: 1857

page_text: LETTERS PATENT to Alexander Parkes, of Birmingham, in the County of
Warwick, Practical Chemist, for the Invention of "IMPROVEMENTS IN
SEPARATING TIN FROM TIN PLATE SCRAP, AND TIN OR ZINC FROM. OTHER
SURPACES OF IRON."
Sealed the 9th June 1857, and dated the 24th February 1857.
PROVISIONAL SPECIFICATION left by the said Alexander Parkes at the
Office of the Commissioners of Patents, with his Petition, on the 24th
February 1857.
I, ALEXANDER PARKES, of Birmingham, in the County of Warwick, Prac-
tical Chemist, do hereby declare the naturo of the Invention for "IMPROVE-
MENTS IN SEPARATING TIN FROM TIN PLATE SCRAP, AND TIN OR ZINC FROM. OTHER
SURFACES OF IRON," to be as follows:-
In order to separate tin from tinned iron, I treat it with strong sulphuric
acid, preferring to use it in a concentrated state, as the stronger the acid the
less action there will be upon the iron, and the tin will be more readily
separated. I prefer to use heat in this part of my Invention, as the separa-
tion is much facilitated-thereby.
I place the acid in an iron or other suitable vessel and then immerse the

page_text: tin scrap to be stripped, and allow it to remain in the bath until I find the tin
dissolved from the iron; this I ascertain by taking out pieces of the scrap from
time to time.
When the tin is separated, I take it out and put in a fresh quantity of scrap
until the acid will no longer act upon the tin; the iron I well wash, when it
will be found very clean and well suited for re-manufacture. To obtain the tin
from the acid, I use any of the well-known methods for obtaining an oxide
sulphuret or other compound of tin, and if preferred, reduced to a metallic
state.
My improvements also consist in the employment of the perchloride or per-
sulphate of iron or manganese, and I proceed as above described. When
either of the salts will not take up more tin, I peroxidize the solution, when
the tin will be separated; or I separate the tin by tho well-known methods,
and the iron'solution will be in a fit state for acting on tin scrap again. This
reaction enables me to use the same solution of iron over and over again for
a long time. In separating tin from iron I employ mercury, which I place
with the tin scrap in an iron barrel or other suitable vessel. I apply a low
heat and cause the tin scrap or tinned iron to be agitated therein; in a short
time-the tin will be separated from the iron; I then remove it and charge
again until the mercury will no longer act upon tho tin properly. I now take
out the amalgam of tin and quicksilver from the vessel, and to obtain the tin
I distil off the quicksilver; as-is well understood. In this case I obtain metallic
tin..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Parkes in the Great Seal Patent Office on the
24th August 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
PARKES, of Birmingham, in the County of Warwick, Practical Chemist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of February, in the year of our
Lord One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
tho said Alexander Parkes, Her special licenco that I, the said -Alexander
Parkes, my executors, administrators, and assigns, or such others as I, the said s
Alexander Parkes, my executors, administrators, and assigns, should at any time

page_text: 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, tho
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
SEPARATING TIN FROM TIN PLATE SCRAP, AND TIN OR ZINC FROM OTHER SURFACES
OF IRON," upon the condition (amongst others) that I, the said Alexander
Parkes, 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
Offico within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Alexander Parkes, do hereby declaro
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 thereof, that is to say:-
In order to separate tin from tinned iron, I treat it with strong sulphuric.
acid, preferring to use it in a concentrated state, as the stronger the acid the
less action there will be upon the iron, and the tin will be more readily
separated. I prefer to use heat in this part of my Invention, as the separation
is much facilitated thereby. I place the acid in an iron or other suitable
vessel and then immerse the tin scrap to be stripped, and allow it to remain in
the bath until I find the tin dissolved from the iron; this I ascertain by taking
out pieces of the scrap from time to time. When the tin is separated, I take
it out and put in a fresh quantity of scrap until the acid will no longer act
upon the tin; the iron I well wash, when it will be found very clean and well
suited for re-manufacture. To obtain the tin from the acid I use any of the
well-known methods for obtaining an oxide sulphuret or other compound of
tin, and if preferred, reduced to a metallic state.
Into any suitable cast-iron vessel, or it may be of lead or other suitable
material, I put at the rate of 1 ton of strong sulphuric acid of the specific gravity
of from 1.65 to 1.85°; I heat the same (by means of steam or otherwise) to
about 200° Fahrenheit; into this acid I introduce from 2 to 3 cwt. of tin
scrap, either in bundles, or placed in a perforated vessel of iron, lead, or carthen-
ware; in a few minutes the tin will be removed from the surface of the iron.
This may be ascertained by introducing trial pieces and examining them from
time to time, when it will be at once seen how the operation is progressing.
As soon as the tin is dissolved off the iron (which, generally speaking, takes
from twenty minutes to half- an hour,) I tako out the iron and well-wash it in

page_text: water; the iron will now be in a suitable state for being re-manufactured into
sheet or bar iron, or it may be used for other purposes. I would remark, that
it has been proposed to uso sulphuric acid largely diluted with water for
separating tin from iron, but I have found that such diluted acid fails to
produce a beneficial result.
My improvements also consist in the employment of the perchloride or
persulphate of iron or manganese, and I proceed as above described. When
either of the salts will not take up more tin I peroxidize the solution, when
the tin will be separated; or I separate the tin by the well-known methods,
and the iron solution will be in a fit state for acting on tin scrap again. This
reaction enables me to use the same solution of iron over and over again for a
long time. For this purpose I prefer that the persalts used should be moderately
concentrated and employed at about the temperature of boiling water; I
introduce the tin scrap, in the proportion above described, in successive charges,
until there is no more action on the tin. Whon this is the case I again per-
oxidise the solution by chlorino or otherwise, as is well understood, when the
tin will be separated as an oxide; or I separate the tin by any of the well-
known means, and thus renders the iron or other solution used fit for acting
upon fresh quantities of the scrap. The iron stripped by this method after
being well washed is fit for re-manufacturer.
In separating tin from iron I employ mercury, which I place with the tin
scrap in an iron barrel or other suitable vessel. I apply a low heat and cause
the tin scrap or tinnod iron to be agitated therein; in a short time the tin will
be separated from the iron; I then remove it and charge again until the
morcury will no longer act upon the tin properly. I now take out the amal-
gam of tin and quicksilver from the vessel, and to obtain the tin I distil off
the quicksilver, as is well understood. In this case I obtain metallic tin. For
this purpose I place 20 lbs. of mercury in an iron barrel or other suitable
vessel, I then introduce from 1 to 2 cwt. of tin scrap, with or without water
or weak acid, close the barrel, and increase the temperature to from 70 to 100°
Fahrenheit. I set the barrel in motion by hand or other power to bring tho
mercury into intimate contact with the tin scrap; I examine it occasionally to
see how the action progresses, and when I find the tin is removed from the
iron, which will generally be in about half an hour from the time of charging,
I take out the scrap and well wash it to free it from the mercury, introduce a
fresh charge, and proceed in the same way so long as the mercury will take
off the tin from the iron. After the removal of the amalgam from the vessel
I distil off the mercury, as is well understood, and obtain the tin in tho metallic
state.

page_text: In conclusion I would state that in separating zinc from iron I apply like
means to that above described.
In witness whereof, I, the said Alexander Parkes, have hereunto set my
hand and seal, this Twenty-fourth day of August, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
JNO. ALCOCK.
ALEXANDER PARKES. (L.S.)