AN IMPROVEMENT IN THE TREATMENT OF SCRAP-ZINC FOR THE RECOVERY OF ZINC AND SOLDER
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
We, ALFRED KIRBY HUNTINGTON of King's College, Strand, in the County of
Middlesex, Professor of Metallurgy, and JAMES HUMPHRYS of Leadenhall
Buildings, in the City of London, Engineer, do hereby declare the nature of our
Invention for "AN IMPROVEMENT IN THE TREATMENT OF SCRAP-ZINC FOR
THE RECOVERY OF ZINC AND SOLDER " to be as follows:-
Scrap zinc usually consists of pieces of plates, spouts or tubes that have been
used, and have become damaged or worn, and these pieces often have on them
solder, or are accompanied by pieces of iron and foreign matters, so that, when
they are melted up, the product is very impure, and there is great loss in the form
of dross.
Our Invention relates to a process for treating scrap zinc, so as to recover nearly
pure zinc from it, and also to recover a large proportion of the solder that often
accompanies it. For this purpose, after assorting the scrap in suitable sizes and
shapes, we cut it up into small pieces, removing all iron and separating those
pieces which have solder on them. We wash the pieces in hot water which may
contain alkali, preferably employing a perforated revolving drum which revolves
in the hot liquid. Having thus cleared the zinc pieces from paint, tar and other
impurities, we melt them, and cast the zinc into ingots. We also wash the pieces
containing solder, and, having melted them, allow the fused mass to cool slowly.
It subsides in two layers which can be separated, the upper layer nearly pure zinc
with a little solder, the lower layer mostly solder with a little zinc. The latter is
melted again and the zinc is separated from it by exposure to air or poling with
superheated steam. The dross produced in the melting of the zinc is treated by
distillation for the recovery of the zinc from it; but the quantity of dross may be
very much reduced by introducing the pieces that are to be melted at a low level
in the melting pot, passing them down a tube through the molten metal.
Dated this 1st day of January 1884
ABEL & IMRAY,
Agents for the Applicants,
28, Southampton Buildings,
London, W.C.

page_text: 18
We, ALFRED KIRBY HUNTINGTON of King's College, Strand in the County of
Middlesex, Professor of Metallurgy, and JAMES HUMPHRYS of Leadenhall
Buildings, in the City of London, Engineer, do hereby declare the nature of our
said Invention for AN IMPROVEMENT IN THE TREATMENT OF SCRAP ZINC FOR
THE RECOVERY OF ZINC AND SOLDER" and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
Scrap zinc usually consists of pieces of plates spouts or tubes that have been
used and have become damaged or worn and these pieces often have on them
solder or are accompanied by pieces of iron and foreign matters, so that when they
are melted up, the product is very impure and there is great loss in the form of
dross.
Our Invention relates to a process for treating scrap zinc so as to recover nearly
pure zinc from it and also to recover a large proportion of the solder that often
accompanies it. For this purpose, after assorting the scrap in suitable sizes and
shapes, we cut it up into small pieces, removing all iron and separating those pieces
which have solder on them. We wash the pieces in hot water which may contain
alkali, preferably employing a perforated revolving drum which revolves in the
hot liquid.
Having thus cleared the zinc pieces from paint, tar and other impurities, we
melt them and cast the zinc into ingots. We also wash the pieces containing
solder and having melted them allow the fused mass to cool slowly, separating
the metals as the mass cools. This melting and cooling can be repeated several
times if required for more complete separation of the metals. The portion
containing mostly solder may be melted again and the zinc may be separated
from it by exposure to air or poling with superheated steam.
The portion containing mostly zinc may be treated as above described by
repeatedly melting and slowly cooling. The dross produced in the melting of the
zinc is treated by distillation for the recovery of the zinc from it; but the
quantity of dross may be very much reduced by introducing the pieces that are to
be melted at a low level in the melting pot, passing them down a tube through the
molten metal.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is :—
The herein described treatment of scrap zinc, for the recovery of zinc and
solder.
ABEL & IMRAY,
Agents for the Applicants,
28, Southampton Buildings,
London, W.C.