Improvements in the Method of Recovery of Tin from Tin Plate Waste and other Waste Tin Products.
Year: 1899

page_text: Date of Application, 2nd Feb., 1899
Complete Specification Left, 25th Oct., 1899-Accepted, 23rd Dec., 1899
PROVISIONAL SPECIFICATION.
Improvements in the Method of Recovery of Tin from Tin Plate Waste
and other Waste Tin Products.
CYRIL TALWORTH BATCHELOR, of Bank Buildings, Cardiff, Civil Engineer, do
hereby declare the nature of this invention to be as follows;—
Subject the tin plate scrap or other waste tin product to the combined &
simultaneous action of chloride of tin and oxygen-either by revolving the same
so that it enters and leaves a tank of approved shape containing chloride of tin.
thus coming into contact with the air, or by dipping & lifting the same in &
out of the chloride, or by forcing heated or other air through the tank contain-
ing the chloride and the scrap, or by oxidising the solution by other means.
The oxygen of the air attacks the tin of the tin chloride converting it to tin
oxide & the chlorine thus released attacks the tin of the scrap converting it
to tin chloride which is, in its turn, converted by the oxygen of the air, to tin
oxide and so on.
The tin oxide falls to the bottom of the tank and is collected & smelted if
so desired.
Dated this Second day of February 1899.
Improvements in the Method of Recovery of Tin from Tin Plate Waste
and other Waste Tin Products.
I, CYRIL TALWORTH BATCHELOR, of Bank Buildings, Cardiff, in the County of
Glamorgan, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention refers to the recovery of tin from tin scrap, tin clippings,
tin plate and other waste tiu products, and consists of an improved method or
process whereby the said recovery is accomplished more expeditiously and effec-
tively than hitherto.
According to this invention the tin scrap or the like is treated with chloride
of tin and oxygen, either simultaneously, or combined and simultaneously,
but in each case so that a fairly rapid chemical action to convert the chloride
of tin into tin oxide is the result.
The most practical method according to this invention is to revolve the tin
scrap to be treated within the chloride of tin bath so that one portion of the
treated scrap dips therein and another portion is exposed to the atmosphere or

page_text: to an oxygen supply for oxidation, the said scrap being lightly bundled together
and rotated slowly so that one particular part of same alternately dips in the
bath and is exposed for oxidation. The scrap treated may be wholly immersed
within the chloride of tin bath, in which case the necessary oxygen would be
passed into and through the said bath so as to combine with the chloride of
tin in the bath in a simultaneous action upon the immersed scrap in forming
tin oxide. Further, the scrap to be treated may be raised and lowered out of
and into the bath and into and out of the atmosphere, although in this instance
the effectiveness of the method according to this invention is in comparison
with the rotating method somewhat limited.
In carrying this invention into effect, the most, commercially practical way
of working is as follows:-Cuttings of tin scrap are pounded within a mould
and around a spindle into a conveniently shaped lightly compressed bundle,
preferably cylindrical. This bundle is mounted to revolve either uniformally
or intermittently upon or within a suitable vat containing tin chloride, and so
that a portion (approximately a half) of the said bundle dips into the chloride
and the other portion is exposed to the atmosphere; the bundle being so lightly
compressed that the chloride can thoroughly circulate throughout the thickness
of the part immersed, and also so that the oxygen of the air can freely attack
the exposed portion of the rotating bundle for the whole of its thickness.
In the treatment, the oxygen of the air attacks the tin chloride on the bundle,
converting it into tin oxide and liberating chlorine, which latter has a simul-
taneous and combined action upon the tin of the scrap, converting the latter
into tin chloride, which is in its turn converted by the oxygen of the air to
tin oxide, the latter if the action is continued long enough falling into the
bottom of the tank and being afterwards suitably collected. Cages or perforated
baskets of acid-resisting material to contain the tin scrap to be treated may be
substituted for, the lightly compressed bundle herein before referred to.
In the case of the lightly compressed bundle, when the tin has been striped
therefrom the remaining iron or steel is withdrawn from the spindle and another
bundle of scrap pounded around it; the section of the said spindle being pre-
ferably angular so that the scrap bundle is fixed upon it for rotation.
The bundle of scrap before treatment is preferably externally bound by a
suitable material, to prevent its opening out during the process.
If the oxygen is forced through the chloride of tin bath while the bundle or
cage of scrap remains stationary in it and totally immersed, the oxygen pre-
ferably takes the form of heated air.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
First. The method herein described for recovering tin from tin-plate scrap
and other waste tin-products, that is to say, subjecting the tin scrap or other
waste tin-product treated to the combined and simultaneous action of chloride
of tin and oxygen, the latter either in the form of atmosphere oxygen outside
the bath or blown in air within the bath.
Second. Treating tin-plate scrap or the like for the recovery of tin by rotat-
ing it partly in and partly out of a chloride of tin bath, by which it is subjected
to the simultaneous and combined action of the chloride of tin and of atmo-
sphere oxygen, in the manner described.
W. P. THOMPSON; & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also at Liverpool, London, and Manchester,
Patent Agents for the Applicant.