AN IMPROVED MODE OF TREATING TIN AND TERNE PLATE SCRAP FOR THE UTILIZATION OF THE SAME
Year: 1876

page_text: LETTERS PATENT to Charles Madge, of Swansca, in the County of Glamorgan,
Mining Engineer, for the Invention of "AN IMPROVED MODE OF TREATING
TIN AND TERNE PLATE SCRAP FOR THE UTILIZATION OF THE SAME."
PROVISIONAL SPECIFICATION left by the said Charles Madge at the Office
of the Commissioners of Patents on the 9th August 1870.
CHARLES MADGE, of Swansea, in the County of Glamorgan, Mining Engineer.
"AN IMPROVED MODE OF TREATING TIN AND TERNE PLATE SCRAP FOR THE
UTILIZATION OF THE SAME."
The object of this Invention is to utilize the scrap or cuttings of tin and terne
plates by removing therefrom the coating metal in an expeditious and economical
manner. To this end I place the scrap in a cylinder or barrel which is mounted
horizontally in a suitable frame, and receives rotary motion from steam or other
motive power.
The cylinder or barrel I fit with longitudinal bars or equivalent projection for
ensuring the turning over and intimate admixture of the contents of the barrel as
rotary motion is imparted thereto.
In order to remove the coating metal from the iron I employ mercury, which I
charge in with the scrap, and 1 supply also to the barrel coarse grit, such as sand or
sifted gravel, which as the barrel is rotated will subject the scrap to attrition and
serve to remove the coating metal from the iron as it becomes reduced by the action
of the mercury to an amalgam. By this means the coating metal of the tin or
terne plate scrap is rapidly removed from the iron, and it can then be recovered in
the way ordinarily employed for separating mercury from metals with which it has
combined.
I may remark that in this process of utilizing the scrap of tin and terne plates
moisture in the form of steam or water may be employed, as the formation of the
amalgam is expedited by the presence of heat, and water will assist to agglomerate
the particles of mercury. The iron thus cleared of tin or other coating metal may
be used with advantage as scrap iron, and the recovered tin or its alloy may be
again used in the manufacture of tin or terne plates

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Madge in the Great Seal Patent Office on the 9th February
1877.
CHARLES MADGE, of Swansea, in the County of Glamorgan, Mining Engineer.
"AN IMPROVED MODE OF TREATING TIN AND TERNE PLATE SCRAP FOR THE
UTILIZATION OF THE SAME."
The object of this Invention is to utilize the scrap or cuttings of tin and terne
plates by removing the coating metal from the iron in an expeditious and economical
manner. To this end I place the scrap in a cylinder or barrel which is mounted in
a suitable frame, and receives rotary inotion from steam or other motive power for
the purpose of subjecting the scrap to attrition. Into this barrel I also charge with
the scrap nail clippings or similar small waste pieces of iron, or it may be sand,
gravel, emery, or other grit, the nail clippings when used being by preference of a
size that will just pass through a screen of one-eighth inch mesh, and I add
thereto mercury which is to form an amalgam with the coating metal of the
scrap.
The cylinder or barrel I fit with longitudinal bars or equivalent projections for
ensuring the turning over and intimate admixture of the contents of the barrel as
rotary motion is imparted thereto, and I thus subject the scrap to effective attrition,
which will facilitate the removal of the coating metal, whether tin or an alloy of
tin and lead, from the iron as it becomes reduced by the action of the mercury to an
amalgam. The time required for thus removing the coating metal from the iron by.
the aid of the rotating barrel will in general be from three to four hours. The
operation may be carried on either in the presence of moisture or as a dry process.
When the scrap has been subjected to attrition for a sufficient time the rotation
of the barrel is stopped and the contents are discharged therefrom on to a coarse
screen, which will retain the scrap iron now freed from the coating metal and allow
the amalgam and the nail clippings to pass through. Below this screen I place at
screen of finer mesh which will arrest the nail clippings and allow the amalgam to
pass through into a vessel prepared to receive it. On to these screens I discharge
a shower of water which will dislodge the amalgam from the scrap iron and carry
it down to the receiving vessel. I then recover the amalgam by filtration or
decantation, and by subjecting the same to heat in a retort I drive off the mercury
and collect it in a metallic state for re-usc.
The iron cleared of its coating metal by the above described process may be used
for the purposes to which scrap iron is at present applied, and the tin or its alloy
forming the residuum of the amalgam in the retort may be utilized in the
manufacture of tin or terne plates, or for other purposes.
Having now explained the nature of my Invention of "An Improved Mode of
Treating Tin and Terne Plate Scrap for the Utilization of the same," and explained
the manner of carrying the same into effect, I wish it to be understood that under
the above in part recited Letters Patent I claim, removing the coating metal from
tin and terne plate scrap by means of attrition in the presence of mercury, as and
for the purpose above described.
In witness whereof, I, the said Charles Madge, have hereunto set my hand
and seal, the Sixth day of February, in the year of our Lord One thousand
eight hundred and seventy-seven.