An Improved Process and Apparatus for Desilverizing Lead.
Year: 1891

page_text: Date of Application, 4th Feb., 1891
Complete Specification Left, 20th Aug., 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION.
An Improved Process and Apparatus for Desilverizing Lead.
A communication to me from abroad by EUGEN HONOLD, Director of Iron
Works, of Stolberg, in the Empire of Germany.
I, EDMUND EDWARDS, of the firm of Edwards and Co., Patent Agents and
Engineers, of 35, Southampton Buildings, Chancery Lane, in the County of
Middlesex, do hereby declare the nature of this invention to be as follows:-
By the improved process which forms the subject of this invention, lead is
desilverized by a short series of operations in a combination of vessels and pans.
In order to put the invention in operation, the lead is melted in a large vessel and
is then by means of a pump or equivalent device passed into a 'conical-shaped
vessel which is divided by suitable vertical partitions, into one of which the melted
lead is introduced, the vessel being heated by a furnace below.
The melted lead passes down under the first partition. which does not reach to
the bottom, and thence up and over the upper edge of the second partition and
through a sufficient quantity of melted zinc which floats upon the surface of the
lead and rises to a level somewhat above the edge of the second partition, the
current of melted lead after passing through the zinc passing down on the under
side of the partition and entering a channel the lower end of which enters the
bottom of the vessel, whilst its upper open end discharges into a flat pan at about
the same level as the surface of the melted zine which is itself preserved from
contact with the air by a suitable covering of a melted alkali.
The flat pan is not heated, so that the lead in it cools and the zinc upon its
surface is separated, being held back by a partition, whilst the lead flows on into
another flat pan heated by a furnace, the melted lead running from it into a second
conical shaped vessel containing some melted zinc through which the lead descends
on account of its greater specific gravity and then passes out through an opening at
the bottom of the conical vessel into another flat pan which is not heated so that
the lead cools, the zinc upon it being separated out whilst the lead passes to a
larger vessel or pan similar to the one first described, in which it is completely
separated from the zinc by the action of steam, which passing through the hot lead
oxidizes the zinc, antimony, and other impurities, which are removed.
If the lead holds many impurities the second vessel described should be pro-
vided like the first one with partitions and melted zinc under and through which
the lead passes.
The lead flowing through the conical vessels takes up a quantity of zinc depen-
dent upon the heat, and the conical shape and depth of the vessels have the
advantage that none of the zinc floating upon the lead is carried away.
The zinc containing the silver collects in the flat pans and also in the two conical
vessels from which it can easily be removed. The large pan in which the lead is
first melted as described may be provided with an opening below through which
the melted lead can be passed into the first of the conical vessels to be treated
there in the manner described.
Dated this 4th day of February 1891.

page_text: COMPLETE SPECIFICATION.
An Improved Process and Apparatus for Desilverizing Lead.
A communication to me from abroad by EUGEN HONOLD, Director of Ironworks,
of Stolberg, in the Empire of Germany.
I, EDMUND EDWARDS, of the firm of Edwards and Co., Patent Agents and
Engineers, of 35, Southampton Buildings, Chancery Lane, in the. County of
Middlesex, 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 and accompanying drawing, that is to say :—
By the improved process which forms the subject of this invention, lead is
'desilverized by a short series of operations in a combination of vessels and pans...
In the accompanying drawing which is in illustration of the invention,
Figure 1 is a plan of the apparatus,
Figure 2. a vertical section through the line X X Figure 1,
Figure 3 a vertical section through Y Y Figure 1, and
Figure 4.a vertical section through Z Z Figure 1.
In order to put the invention in operation, the lead is melted in a large- vessel A
and is then by means of a pump or equivalent device passed into a conical shaped
vessel B which is divided by a suitable vertical partition R into one division of
which vessel the melted lead is introduced, the vessel being, heated by a furnace. H
below.
The melted lead passes down under the first partition R which does not reach to
the bottom, and thence up and over the upper edge of the second partition P and
through a sufficient quantity of melted zinc which floats upon the surface of the
lead and rises to a level somewhat above the edge of the second partition P, the
current of melted lead after passing through the zinc passing down on the under
side of the partition and entering a channel B' the lower end of which enters the
bottom of the vessel, whilst its upper open end discharges into a flat pan G at
about the same level as the surface of the melted zinc which is itself preserved from
contact with the air by a suitable covering of melted alkali.
In Figure 2 the horizontal lines represent the fluid lead passing in the direction
shewn by the arrows, the vertical lines above represent the melted zinc, and the
black line above the zinc, the melted alkali.
The pan G is not heated, so that the lead in it cools, and the zinc upon its surface
is separated, being held back by a partition J, whilst the lead flows on into another
pan L heated by a furnace K, the melted lead running from it into a second conical
shaped vessel C also containing some melted zinc through which the lead descends
on account of its greater specific gravity and then passes out through an opening C₁
at the bottom of the conical vessel into another pan M which is not heated so that
the lead cools, the zinc upon it being separated out whilst the lead passes to a
larger vessel or pan N similar to the one first described, in which it is completely
separated from the zinc by the action of steam, which passing through the hot lead
oxidizes the zinc, antimony, and other impurities, which are removed.
If the lead holds many impurities the second vessel C described should be
provided like the first one B with partitions R and P and melted zinc under and
through which the lead passes.
The lead flowing through the conical vessels B and C takes up a quantity of zinc
dependent upon the degree of heat, and the conical shape and depth of the vessels
have the advantage that none of the zinc floating upon the lead is carried away.
The zinc containing the silver collects in the pans, and also partly in the two
conical vessels from which it can easily be removed. The large pan A in which
the lead is first melted as described may be provided with an opening O below,
through which the melted lead can be passed into the conical vessel B to be treated
there in the manner described.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. For the continuous desilverizing of lead, the arrangement of the pan or
vessel A, the conical vessel B, the pans G and L, the conical vessel C, the pan M
and the vessel N, in combination with the furnaces H and K, substantially as
described and shewn.
2. In the apparatus described and claimed in Claim 1, the arrangement of the
partitions R and P in the conical vessel, round and over which and through
the zinc, the melted lead is compelled to pass, substantially as described and
shewn.
Dated this 20th day of August 1891.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.