AN IMPROVED PROCESS FOR SEPARATING OR REMOVING THE TIN FROM SCRAPS OR CUTTINGS OF TINNED OR TERNE PLATES, AND IN APPARATUS FOR THAT PURPOSE
Year: 1873

page_text: LETTERS PATENT to William Robinson, of Old Bailey, in the City of
London, for the Invention of "AN IMPROVED PROCESS FOR SEPARATING
OR REMOVING THE TIN FROM SCRAPS OR CUTTINGS OF TINNED OR TERNE PLATES,
AND IN APPARATUS FOR THAT PURPOSE."
Scaled the 7th November 1873, and dated the 10th May 1873.
PROVISIONAL SPECIFICATION left by the said William Robinson at
the Office of the Commissioners of Patents, with his Petition, on
the 10th May 1873.
I, WILLIAM ROBINSON, of Old Bailey, in the City of London, do
hereby declare the nature of the said Invention for "AN IMPROVED PROCESS
POR SEPARATING OR REMOVING THE TIN FROM SCRAPS OR CUTTINGS OF TINNED OR
TERNE PLATES, AND IN APPARATUS FOR THAT PURPOSE," to be as follows:-
The object of this Invention is the recovery of the tin from the scraps
or cuttings of tinned iron plate, the said tin being now commonly wasted,
and thus lost to commerce.

page_text: The agent I employ for stripping or separating the tin from the sheet
iron is quicksilver. I am aware that this agent has been used before for
the same object, and successfully so far as the recovery of the tin is
concerned; but owing to the loss of quicksilver no process that I am
aware of has proved a commercial success, whilst the health of the a
workmen has severely suffered from the inhalation of the quicksilver
fumes. To obviate this objection I propose therefore to carry on and
complete the process in closed air-tight vessels, by which I obviate the
deleterious effects of the vapour of quicksilver; and further, to prevent
the loss of the quicksilver, I fill such air-tight vessels with any gas or 1
vapour which will not be capable of reacting on either the quicksilver
or the tin so as to waste or destroy it or impair its value.
The means by which I accomplish these objects are as follows:
First. The tin plate cuttings or scraps are agitated with a suitable
quantity of quicksilver in a closed vessel filled with gas or vapour as 1
aforesaid until the tin is disolved in the quicksilver.
Second. The cuttings are taken from the agitating vessel by any suit-
able instrument and transferred to another vessel, where they can be
washed with water to get rid of the scurf or scum that may arise from
the original foulness of the cuttings.
Third. The cuttings are then transferred to suitable retorts for dis-
tilling off the quicksilver that may adhere to them. These retorts are
connected by air-tight joints to their respective receivers, and these
receivers are filled with gas or vapour to prevent oxidation of the quick-
silver as it distils over. Repeated operations are performed with the
quicksilver remaining in the agitator until by its increasing viscidity it
is considered so far charged with tin as to require separation.
Fourth. The quicksilver is discharged from the agitator by suitable
appliances, and is then transferred to the retort to be distilled, by which
the quicksilver comes over and the tin remains in the retort.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robinson in the Great Seal Patent Office
on the 10th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBINSON, of Old Bailey, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of May, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto I, the said William Robinson, Her special licence
that I, the said William Robinson, my executors, administrators, and
assigns, or such others as I, the said William Robinson, my executors,
administrators, and assigns, should at any time 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, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED PROCESS FOR
SEPARATING OR REMOVING THE TIN FROM SCRAPS OR CUTTINGS OF TINNED OR
TERNE PLATES, AND IN APPARATUS FOR THAT PURPOSE," upon the condition
(amongst others) that I, the said William Robinson, 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
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE that I, the said William Robinson, do hereby
declare the nature of my said Invention and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :-
The object of this Invention is the recovery of the tin from the scraps
or cuttings of tinned iron plate, the said tin being now commonly wasted,
and thus lost to commerce.
The agent I employ for stripping or separating the tin from the sheet
iron is quicksilver. I am aware that this agent has been used before for
the same object, and successfully so far as the recovery of the tin is

page_text: .
4
concerned; but owing to the loss of quicksilver no process that I am
aware of has proved a commercial success, whilst the the health of the
workmen has severely suffered from the inhalation of the quicksilver
fumes. To obviate this objection I propose therefore to carry on and
complete the process in closed air-tight vessels, by which I obviate the
deleterious effects of the vapour of quicksilver; and further, to prevent
the loss of the quicksilver, I fill such air-tight vessels with any gas or
vapour which will not be capable of reacting on either the quicksilver
or the tin so as to waste or destroy it or impair its value.
The means by which I accomplish these objects are as follows :- 1
First. The tin plate cuttings or scraps are agitated with a suitable
quantity of quicksilver in a closed vessel filled with gas or vapour as
aforesaid until the tin is disolved in the quicksilver.
Second. The cuttings are taken from the agitating vessel by any suit-
able instrument and transferred to another vessel, where they can be 1
washed with water to get rid of the scurf or scum thay may arise from
the original foulness of the cuttings.
Third. The cuttings are then transferred to suitable retorts for dis-
tilling off the quicksilver that may adhere to them. These retorts arc
connected by air-tight joints to their respective receivers, and these
receivers are filled with gas or vapour to prevent oxidation of the quick-
silver as it distils over. Repeated operations are performed with the
quicksilver remaining in the agitator until by its increasing viscidity it
is considered so far charged with tin as to require separation.
Fourth. The quicksilver is discharged from the agitator by suitable a
appliances, and is then transferred to the retort to be distilled, by which
the quicksilver comes over and the tin remains in the retort.
And in order to explain this Invention more fully I will now proceed
to describe the means by which it may be carried into practical effect,.
reference being had to the illustrative Sheet of Drawings accompanying
these Presents, and to the numeral figures and letters of reference marked

page_text: Figure 8 is another box which fits into the pot retort H.
MODE OF OPERATION.
Tin scraps and mercury are placed in the turbine. A charcoal or
other suitable material, as hereafter described, is then lighted on the top
of the mixture, and the said turbine is then closed by the lid B. When
all the air has been burnt and the apparatus filled with an inert atmo-
sphere rotatory or semi-rotatory motion is then imparted to the axle D
and prongs a and b, and the tin of the scraps and the mercury arc thus
brought into perfect contact with each other, and when their mixture
has been thoroughly effected the motion is stopped, the lid taken off,
and the tin scraps placed by means of a fork in the box shown at
Figure 7. This box is then introduced into the retort G; the heat from
the fire distills the amalgam which still remains attached to the scraps,
and the amalgam is condensed by passing along the pipe I into the
condenser at Figure 6, which is filled with an inert atmosphere. The
retort G should be inclined as represented at Figure 4, and fitted with a
pipe I for discharging the amalgam from the box shewn at Figure 7.
The amalgam which has not been removed from the turbine A, as well
as the amalgam distilled in the condenser, are then put together in the
box shown at Figure 8, charcoal being then lighted on the top of the
box. It is then introduced into the pot retort at H, Figure 5, and closed

page_text: up. Free mercury distills into the condenser by the pipe, and the c
alone is left in the box H, which may be removed and cast into ingots
ready for the market, and the mercury remains intact for succeeding
operations.
.
I would here remark that the agitation and washing herein-before
described will only be necessary when the cuttings are very foul. If the
cuttings are quite bright and clean both the first and second operations
may be dispensed with and the apparatus disposed as follows:-The
retort G is placed vertically and connected by a pipe with the pot retort
H, a valve being provided between the two retorts. The said pot retort
is connected with the condenser at Figure 6, as herein-before described.
By means of the said apparatus the operation will be conducted as
follows: The cuttings are placed at once into the retort G, and the air
being consumed or expelled by means herein-after described or other
suitable means, the quicksilver may be poured in upon the cuttings and
the lid closed. The heat is then raised, and the quicksilver will be found
to form amalgam direct with the tin, the said amalgam condensing in
the aforesaid pot retort H. The valve between the two retorts is then
closed and heat applied under the said pot retort H. The quicksilver
will now separate itself from the tin amalgam, condensing in the con-
denser at Figure 6, and the tin remains in the pot retort H, from which
it may be cast into ingots.
The means I propose to employ for producing an inert vapour in the
interior of the aforesaid vessels are the introduction of burning charcoal,
straw, firewood, waste paper, or other suitable material, so as to produce
carbonic acid or carbonous oxide, but any other inert gas, however pro-
duced, will answer the same purpose.
Having now described the nature and object of my said Invention
for "An Improved Process for Separating or Removing the Tin from
Scraps or Cuttings of Tinned or Terne Plates, and in Apparatus for that
Purpose," and the means whereby it may be effected, I would remark in
conclusion that I do not intend to limit or confine myself to the precise
details or form of apparatus before described, but what I claim as my
Invention and desire to secure by the herein-before in part recited
Letters Patent is, the treatment of tin scraps or cuttings of tinned or
terne plates with quicksilver in closed vessels filled with an inert gas or

page_text: vapour so as to separate and recover the tin, iron, and quicksilver
without loss or deterioration, substantially as described.
In witness whereof, I, tho said William Robinson, have hereunto
set my hand and seal, this Tenth day of November, in the
year of our Lord One thousand cight hundred and seventy-
three.