Improvements in the Method or and means for 444 from Tinned Sheet Metal Cuttings by Means of Hydrochloric Aold Gas.
Year: 1886

page_text: Date of Application, 27th Feb., 1886.
Complete Left, 27th Nov., 1886.
Complete Accepted, 25th Feb., 1887.
Improvements in the Method or and means for
444
from Tinned Sheet Metal Cuttings by Means of Hydrochloric
Aold Gas.
I, FERDINAND BOSSHARDT, of the firm of Bosshardt & Grant of 24 & 32 Bulls
Head Exchange Chambers Market Place, Manchester, in the County of Lancaster,
Mechanical & Consulting Engineers and Patent Agents, do hereby declare the nature
of this invention to be as follows:-
This invention relates to improvements in the method of & means for extracting
the tin from tinned sheet metal cuttings by means of hydrochloric acid & consists
gas
= Sn Cl, + H₂),
in passing a current of HCl gas, (chemical formula 2H Cl + Sn
over the tinned sheet metal cuttings, which tinned sheet metal is composed of sheet
metal covered with tin Sn. By dissolving the salt Sn Cl, in water a solution is
obtained in which the tin is precipitated, by the ordinary zinc.
The hydrochloric acid is produced in the ordinary manner by a furnace in a cast
iron cylinder, which latter is in communication with a vessel containing the sheet
metal cuttings, by means of a pipe.
This vessel is formed with two openings arranged to be closed hermetically, for the
charge & discharge of the sheet metal cuttings, and is also provided with a tap for
the purpose of drawing off the solution of proto-chloride into a reservoir situated
below the said tap.
The said vessel is also in communication by means of a pipe, with a steam generator,
by means of which the sheet metal cuttings are heated to a temperature of from
65° to 70°.
The vessels containing the sheet metal cuttings, is provided with a spray arrange-
ment, which by means of another pipe is in communication with a force pump, by
means of which the sheet metal cuttings are washed.

page_text: When the hydro-chloric acid gases pass on the tinned sheet metal cuttings, this
acid combines with the tin and forms a proto-chloride of tin.
The tinned sheet metal cuttings being cleaned by means of the proto-chloride of tin,
are washed away by the water, & held in suspension in this water, to be put in
receptacles.
The zinc particles are then put in the receptacles, the zinc and the proto-chloride
combine together, the tin becomes freed & remains clearly and absolutely pure.
The water is extracted from the precipitated tin by means of a press and the tin
melted into ingots by means of a crucible.
Pro F. BOSSHARDT,
Bosshardt & Grant,
Agents to the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Method of and Means for Extracting the Tin
from Tinned Sheet Metal Cuttings by Means of Hydrochloric
Aoid Gas.
I, FERDINAND BOSSHARDT of the firm of F. Bosshardt & Co. of 4 Corporation
Street Manchester in the County of Lancaster, Engineer and Patent Agent, do
hereby declare the nature of this invention which has been communicated to me from
abroad by S. Montagne of Nantes in the Republic of France, Engineer, and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement :-
This invention has for its objeet a method and apparatus for separating the tin
from tinned sheet metal, such as empty tin boxes, scrap tinned iron or tinned sheet
metal cuttings.
Broadly speaking, the method consists in conveying hydro-chloric acid gas into
a closed vessel containing the material, the separation of the tin of which, it is desired
to obtain.
After the closed vessel containing the tinned sheet metal has become completely
saturated with hydro-chloric acid gas, whereby the latter combines with the tin,
a shower of water is allowed to fall over the sheet metal, and instantaneously the said
gas is converted into liquid proto-chloride of tin; the tin, entirely removed from the
sheet metal, is dissolved in the said protochloride of tin.
The proto-chloride of tin is drawn off from the closed vessel and the tin is
precipitated either by means of zine or by means of limewash or otherwise. The tin
obtained is absolutely pure.
The sheet metal left in the closed vessel is also absolutely pure.
In the accompanying drawing, A is a retort into which is placed a charge of
sulphuric acid and chloride of sodium for producing, with the application of heat,
hydro-chloric acid gas in the usual manner.
The hydrochloric acid gas produced is conveyed by a pipe B¹ into a closed vessel B
containing a charge of tinned sheet metal scrap or cuttings.
The latter material is heated to a temperature of 150 to 160 degrees Fahrenheit, by
a jet of steam supplied by a generator D, and a pipe D.
After the tinned sheet metal cuttings, or scrap, have become saturated with hydro-
chloric acid gas, a shower of water, supplied by a pump F and a pipe C, is conveyed
into the closed vessel B by a perforated pipe E, so as to completely wash over the
tinned sheet metal scrap. The solution thus produced is protochloride of tin which
is drawn off into a pan H by a tap G.
The tin contained, in dissolution, in the protochloride of tin is precipitated either
by means of zinc or otherwise; the precipitated tin is placed under a press M for
extracting any liquid remaining therewith, and is then melted into ingots, in a
crucible P.

page_text: The tin then obtained is absolutely pure. The sheet metal left in the closed
vessel B has re-assumed its original state of purity and may be worked into fresh
marketable metal.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed I declare that what I claim is :-
The method of and apparatus for extracting the tin from tinned sheet metal
scrap or cuttings by means or hydrochloric acid gas, substantially as described and
illustrated.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester,
Agents to the Applicant.