посогон ща още це тог пошадшахтите, also in Apparatus to be Employed in this Treatment.
Year: 1886

page_text: посоvеr тип апа во 1гон ща още це тог пошадшахтите,
also in Apparatus to be Employed in this Treatment.
I THOMAS FENWICK of 172 Fleet Street in the City of London Manager of
Electro Plating Works 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 has for its object improvements in the treatment of waste tin
cuttings to recover tin and also iron in a state fit for remanufacture also in apparatus
to be employed in this treatment.
I make use for this purpose of a series of baths of earthenware or other insulating
material and I place in these baths a liquid suitable for the electro deposition of
tin. Preferably I employ a saturated solution in water of protochloride of tin.
I place in these baths receiving plates of metal preferably tin upon which the
tin stripped from the waste cuttings is deposited. I also place in each bath a
basket preferably of wicker work to receive the waste tin cuttings from which the
tin is to be removed. I employ also a continuous current dynamo electric machine
and I arrange it in series with many of these baths connecting one pole of the
dynamo with the waste cuttings in the first bath of the series and the other
dynamo with the receiving plates of the last bath of the series in between these
points I connect the baths together the receiving plates of the first bath with the
waste tin cuttings in the basket of the second bath and so on from bath to bath
throughout the series. I cause the waste tin cuttings to be turned over by hand
or otherwise during the operation so that they may be uniformly acted upon. I do
not continue the operation so far as to remove all the tin from the waste cuttings
for were I to do so iron would be dissolved and in consequence after a time the
bath would become unfit for use. But after a few minutes when the operator
judges that the process is insufficiently advanced the cuttings should be removed
from the baskets. The cuttings so removed are replaced by other fresh cuttings
and so the process goes on say for a week continuously. The receiving plates
I coat preferably with plumbago or black lead so that the deposited tin may not
adhere to them but fall away to the bottom of the bath beneath each receiving
plate and within the bath I place a narrow collecting trough also preferably
of earthenware in which the tin falling from the plate is collected and stored,

page_text: Similarly also within the bath I place another shallow receiving trough of suitable
dimensions beneath the basket in which the tin cuttings are placed to receive and
collect any metallic or other particles which may pass out from the baskets.
When the process has been carried on for a considerable time, say for a week the
liquid is run out of the bath and the receiving plates are lifted out and the tin
adhering to them is removed by brushing. The collecting troughs are also removed
with the bin and deposit which they contain. The liquid is if necessary filtered
through a bed of sand and the solution is made up to the requisite quantity by the
addition of Fresh Chloride of Tin; this also is done during working to make good
the liquid which is necessarily removed with the tin cuttings when they are taken
out of the bath.
The cuttings which have been treated in the manner already described and
which still have some tin upon them are placed in a bath of strong muriatic acid
and here they are to remain for about an hour in which time the muriatic acid
will have removed practically the whole of the tin whilst the iron is but little
acted upon. The cuttings when removed from the acid bath are drained then
washed with water and dried they are then ready for the market as scrap iron fit
for further manufacture.
When the acid has become so far charged with tin as to impare its action it is
treated to remove the tin and render it fit for further use in the following
manner :-
It is put into baths preferably of earthenware and like those already described
and each containing a carbon electrode and a plate of tin the baths are arranged
in series and the current of a dynamo machine is passed through the baths.-These
acid baths may be in the same series with the stripping baths. This treatment
causes the tin to be deposited upon the metal plates and the acid is left in a state
fit for re-use.
In order that my invention may be fully understood I will describe more in
detail the way in which I prefer to arrange the apparatus.
The baths which I use are two feet wide and two feet deep and three feet in
length and they are made of pottery ware. I form a series say of 100 or 120 of
such baths this is suitable for a dynamo machine which when coupled with the
baths in series will give a potential of 48 volts and a current of 650 amperes.-
I use tin receiving plates by preference though this is not essential. The plate in
each case is somewhat shorter than the bath so that it may enter freely within it
lengthways and its depth is such that it descends to within about three inches
from the bottom of the bath. I attach each plate to a wooden bar or I provide it
with lugs to rest upon the ends of the bath and support it. There are two
receiving plates in each bath one on either side. The receiving plates are
thoroughly brushed over with black lead before being placed in the baths.
Beneath each plate and within the bath there is a moveable trough running the
whole length of the bottom of the bath about three inches wide and three inches
deep; the lower edge of the receiving plate dips down into this trough. Between
the two receiving plates is the wicker-work basket in which the waste cuttings
are placed. This basket may conveniently be about two feet six long eighteen
inches wide and of the same depth; it is open at the top and carried by two
wooden rods fixed to its upper edges; these bear upon the ends of the earthenware
baths beneath this basket a shallow earthenware trough is provided; its
dimensions are such that it nearly covers the bottom of the trough except in those
parts where the metal receiving troughs are placed. Each bath is provided with a
draw off orifice at the bottom, by opening which the liquid can be drawn off
without disturbing the metal in the metal trough or the deposit in the vessel
beneath the wicker basket.
I make the connections by means of stout bands of metallic tin. I provide such
a band running around the wicker basket, and I lead this away to a clamping
screw conveniently placed, it may be upon a copper rod supported in any con-
venient manner between the baths. The tin band can be wrapped around the rod

page_text: and clipped to it by means of screws. Similarly from each of the receiving plates
a like band of tin passes, and this in like manner is secured to one of the copper
rods employed in forming the connections.
The cuttings which should be reduced to convenient sizes will generally remain
in the basket about ten minutes and during this time they are turned over several
times by the attendant at the trough. The tin band within the basket serves to
make an efficient electrical connection with the cuttings. The band itself is slowly
dissolved but this is not of great importance as the metal is recovered.
The acid tanks which receive the cuttings after treatment in the electrical
stripping bath may conveniently be sufficiently large to receive the cuttings from
say ten or twelve of these.
The same acid is employed until it ceases to operate efficiently and then it is
treated to separate the tin. This may be done in baths in the same series and in
these acid baths the cuttings are replaced by an electrode of carbon.
The acid may be continuously passed through these baths being drawn off as
soon as the percentage of tin in it is sufficiently reduced and passed again into
the acid tanks.
The tin is in this process recovered for the most part in the form of small flakes
to prepare it for the market it is washed in water and dried and then by pressing
or stamping it is driven into strong cast iron moulds and so blocks of about the
size of bricks are obtained. A pressure of about 13 tons to the square inch will be
found suitable for moulding these blocks. The moulds are made to open to deliver
the blocks-they should be a good deal tapered and the pressure should be applied
on the broadest face of the block.
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:-
1. The treatment of waste tin cuttings by the aid of a dynamo current in
baths connected in series and charged with protochloride of tin substantially as
described.
2. The treatment of waste tin cuttings by the aid of an electric current in baths
charged with proto-chloride of tin and afterwards with muriatic acid substantially
as described.
3. The treatment of waste tin cuttings in electrolitic baths by the aid of a
dynamo current and afterwards with muriatic acid such acid being subsequently
prepared for re-use by the passage of a dynamo current substantially as described.
4. In the treatment of waste tin cuttings by the aid of an electric current, the
use of receiving plates coated with plumbago or like material and collecting troughs
beneath these plates substantially as described.
5. In the treatment of waste tin cuttings by the aid of an electric current, the
method of preparing the recovered tin for the market by pressing or stamping it
into moulds substantially as described.
6. The arrangement of apparatus for the treatment of waste tin cuttings
substantially as described.
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