IMPROVEMENTS IN THE RECOVERY OF TIN FROM SCRAP TIN PLATE
Year: 1882

page_text: LETTERS PATENT to Arthur Thomas Becks of Aston near Birmingham in
the County of Warwick Metallurgist for an Invention of "IMPROVEMENTS
IN THE RECOVERY OF TIN FROM SCRAP TIN PLATE."
PROVISIONAL SPECIFICATION left by the said Arthur Thomas Becks at
the Office of the Commissioners of Patents on the 5th August 1882.
ARTHUR THOMAS BECKS of Aston near Birminghain in the County of Warwick
Metallurgist "IMPROVEMENTS IN THE RECOVERY OF TIN FROM SCRAP TIN
PLATE
35
In the ordinary treatment of scrap tin plate for the recovery of tin therefrom, the
said scrap is treated by acids which dissolve the coating of tin from the iron and
leave the iron wholly or in great part undissolved. In order to recover the tin
from this solution it is treated with carbonate of lime in the form of chalk. The
chalk is mixed with water to the consistence of a thin cream or milk which is
slowly added to the solution of tin. The mixture requires nearly constant stirring
and attention on the part of the operator as the escape of carbonic acid gas makes
the solution froth By.this treatment the tin is thrown down from the solution as
bydrated oxide of tin.
In recovering the tin according to my Invention from the acid solution obtained
by treating the scrap tin plate by acids I proceed as follows. Instead of using
throughout the recovering process, carbonate of lime in the state of chalk; that is in
the state of non-crystalline or amorphous carbonate of lime, I first employ
crystalline carbonate of lime; that is marble or other kinds of crystalline carbonate
of lime I add fragments of marble or crystalline carbonate of lime to the solution
of tin and allow it to remain in the solution until the whole of the free acid present
is neutralized and the action of the marble on the solution ceases. I then renove
the marble and effect the precipitation of the hydrated oxide of tin by the addition
of a mixture of chalk.and water. By operating in the manner described great
economy is effected as no supervision is required during the action of the marble
on the solution, there being little or no frothing during the action of the marble and
consequently no necessity to break the froth as is necessary when the process is
conducted wholly by the use of chalk

page_text: に
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arthur Thomas Becks in the Great Seal Patent Office on the
26th January 1883.
ARTHUR THOMAS BECKS of Aston near Birmingham in the County of Warwick,
Metallurgist
"IMPROVEMENTS IN THE RECOVERY OF TIN FROM SCRAP TIN
PLATE
"
In the ordinary treatment of scrap tin plate for the recovery of tin therefrom,
the said scrap is treated by acids which dissolve the coating of tin from the iron
and leave the iron wholly or in great part undissolved. In order to recover the
tin from this solution, it is treated with carbonate of lime in the form of chalk.
The chalk is mixed with water to the consistence of a thin cream or milk which is
slowly added to the solution of tin.
The mixture requires nearly constant stirring and attention on the part of the
operator as the escape of carbonic acid gas makes the solution froth. By this
treatment the tin is thrown down from the solution as hydrated oxide of tin.
In recovering the tin according to my invention from the acid solution obtained
by treating the scrap tin plate by acids, I proceed as follows. Instead of using
throughout the recovering process, carbonate of lime in the state of chalk, that is
in the state of non-crystalline or amorphous carbonate of lime. I first employ
crystalline carbonate of lime, that is, marble or other kinds of crystalline carbonate
of lime. I add fragments of marble or crystalline carbonate of lime to the solution
of tin and allow it to remain in the solution until the whole or nearly the whole of
the free acid present is neutralized and the action of the marble on the solution
ceases. I then remove the marble and effect the precipitation of the hydrated
oxide of tin by the addition of a mixture of chalk and water. By operating in the
manner described, great economy is effected, as no supervision is required during
the action of the marble on the solution, there being little or no frothing during
the action of the marble and consequently no necessity to break the froth as is
necessary when the process is conducted wholly by the use of chalk.
In carrying my invention into effect, I operate on the tin plate scrap by means
of acids in the usual way and when the acid has ceased to act on the scrap tin
plate and is practically saturated, I transfer it to a tank which I will call the
precipitating tank.
I place the marble or crystalline carbonate of lime with which the solution is to
be first treated, in a cage or perforated vessel suspended over the precipitating
tank in which the solution to be operated upon is contained, and into which tank
the said cage or perforated vessel can be lowered and from which it can be raised
by a suspending chain passed over a pulley or otherwise. The said cage or
perforated vessel containing the marble or crystalline carbonate of lime is raised
from the solution in the tank at intervals of about six hours and the carbonate of
lime is rinsed with water in order to remove any adherent oxide of tin which
impedes the action of the carbonate of lime on the solution. When the marble or
crystalline carbonate of lime ceases to act as is indicated by the cessation of
effervescence and which occurs in from one to two days, the solution is treated
with the mixture of chalk and water either in the same or in another tank.
precipitated hydrated oxide of tin obtained is washed or washed and dried in the
ordinary way and may either be reduced to metallic tin in the usual way or applied
to any of the uses to which hydrated oxide of tin is applicable.
The
Having now described the nature of my invention and the manner in which the

page_text: same is to be performed I wish it to be understood that I claim as my invention
of "Improvements in the recovery of tin from scrap tin plate."
Operating upon the solution of tin obtained by the action of acids on scrap tin
plate by marble or other crystalline carbonate of lime previous to the precipitation
from the said solution of hydrated oxide of tin by a mixture of chalk and water
substantially as hereinbefore described.
In witness whereof I the said Arthur Thomas Becks have hereunto set my
hand and seal this twenty fourth day of January in the year of our Lord
One thousand eight hundred and eighty three.
Witness,
GEORGE SHAW
ARTHUR THOMAS BECKS. (L.S.)