A NEW OR IMPROVED PROCESS FOR REFINING AND DESILVERING LEAD AND APPARATUS EMPLOYED FOR THAT PURPOSE
Year: 1869

page_text: LETTERS PATENT to Charles Denton Abel, of No. 20, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Patent
Agent, for the Invention of "A NEW OR IMPROVED PROCESS FOR REFINING
AND DESILVERING LEAD AND APPARATUS EMPLOYED FOR THAT PURPOSE."―A
communication from abroad by Messrs. Gustave Luce, Son, and
Rozan, of No. 44, Rue Sainte, Marseilles, France, Merchants.
Scaled the 6th May 1870, and dated the 15th November 1869.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel
at the Office of the Commissioners of Patents, with his Petition,
on the 15th November 1869.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings, Chancery
Lane, in the County of Middlesex, Patent Agent, do hereby declare the
nature of the said Invention for "A NEW OR IMPROVED PROCESS FOR REFINING
AND DESILVERING LEAD AND APPARATUS EMPLOYED FOR THAT PURPOSE," to be as
follows:-
This Invention consists in refining and desilvering lead by means of
steam. For this purpose the crude argentiferous lead is melted down

page_text: in a vessel heated by a fire and provided at its lower end with a spout
closed with a slide, through which when the lead is melted it is caused to
flow down into a lower vessel or vat heated only at times directly by
a special fire, and at other times by the waste heat from the fire of the
When the lower vessel is full steam is introduced
upper vessel.
through a central pipe leading down to near the bottom of the vessel,
where it is provided with a cock turned by a rod from above, and with
a disc for the purpose of dividing the steam as it enters. The steam
in passing up through the molten lead effectually oxidizes all impurities,
which then rise in the form of scum to the top of the metal, whence
they are removed. The introduction of the steam at the same time pro-
duces a violent ebullition of the lead causing it to crystallize, and when
this crystallization has taken place to a sufficient extent the introduction
of steam is stopped by closing the cock on the steam pipe, and the re-
maining liquid portion of the lead in which the greater proportion of
the silver will be found concentrated is run off through one or more
spouts into troughs turning on pivots for conducting the lead into a
series of ingot moulds. During this time a fresh charge of lead con-
taining a per-centage of silver approximating to that of the crystals in
the lower vessel has been melted down in the upper vessel, and is run
into the lower vessel as soon as all the liquid portion has been removed
therefrom. Steam is then again introduced effecting a further purifi-
cation and separation of silver, and this process is continued until by
the repeated crystallization one part of the lead is rendered comparatively
free from silver, to be used as merchant lead, while the lead run off is
sufficiently rich in silver for the cupelling process.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Denton Abel in the Great Seal Patent Office
on the 13th May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
DENTON ABEL, of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her.
Lotters Patent, bearing date the Fifteenth day of November, in the year
of our Lord One thousand cight hundred and sixty-nine, in the thirty-

page_text: third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Denton Abel, Her special
licence that I, the said Charles Denton Abel, my executors, adminis-
trators, and assigns, or, such others as I, the said Charles Denton
Abel, 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,
usc, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"A NEW OR IMPROVED PROCESS FOR REFINING AND DESILVERING LEAD AND
APPARATUS EMPLOYED FOR THAT PURPOSE," a communication to me from abroad
by Messrs. Gustavo Luce, Son, and Rozan, of No. 44, Rue Saint,
Marseilles, France, Merchants, upon the condition (amongst others)
that I, the said Charles Denton Abel, 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 Charles Denton Abel, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accom-
panying Sheet of Drawings, and to the figures and letters marked thereon,
that is to say :-
This Invention consists in refining and desilvering lead by means of
steam. For this purpose the crude argentiferous lead is melted down
in a vessel heated by a fire, and provided at its lower end with a spout
closed with a slide, through which when the lead is melted it is caused
to flow down into a lower vessel or vat heated only at times directly
by a special fire, and at other times by the waste heat from the fire
of the upper vessel. When the lower vessel is full steam is introduced
through a central pipe leading down to near the bottom of the vessel,
where it is provided with a cock turned by a rod from above and with
a disc for the purpose of dividing the steam as it enters. The steam
in passing up through the molten lead effectually oxidizes all impurities,
which then rise in the form of scum to the top of the metal, whenco

page_text: they are removed. The introduction of the steam at the same time
produces a violent ebullition of the lead causing it to crystallize, and
when this crystallization has taken place to a sufficient extent the intro-
duction of steam is stopped by closing the cock on the steam pipo and
the remaining liquid portion of the lead in which the greater pro-
portion of the silver will be found concentrated is run off through one
or more spouts into troughs turning on pivots for conducting the lead
into a series of ingot moulds. During this time a fresh charge of lead
containing a per-centage of silver approximating to that of the crystals
in the lower vessel has been melted down in the upper vessel, and is
run into the lower vessel as soon as all the liquid portion has been
removed therefrom. Steam is then again introduced effecting a further
purification and separation of silver, and this process is continued until
by the repeated crystallization one part of the lead is rendered com-
paratively free from silver to be used as merchant lead, while the lead
run off is sufficiently rich in silver for the cupelling process.
Figure 1 of the Drawings shows a vertical section of the apparatus;
Figure 2 shews a section at right angles to the section at Figure 1;
and Figure 3 shews a plan.
A is the crystallizing vat, and H is the upper melting cauldron; Bis
the pipe for introducing steam into the vat A, which pipe is provided
at its lower, end with a steel cock C actuated by the rod E attached to
an arm K fixed to the plug of the cock; F, F, are spouts adapted to
the vat A, and F' is a similar spout adapted to the cauldron H. Each
spout is closed or opened by means of a lever N (shewn in detail to a
larger scale at Figures 4 and 5) hinged at O, which constitutes a slide
fitting exactly against the planed surface of the flange I on the end of
the spout, the slide being kept against the flange by means of the
guide S secured to the flange by means of two screw bolts T, by screwing
up which to a greater or less degree the pressure of the slide against.
the orifice of the spout is regulated. By lifting the slide the orifice of
the spout is uncovered more or less so as to regulate the flow of tho
melted lead. In operating with this apparatus steam is introduced
through the pipe B into the vat A, which steam in passing in is distributed
equally by passing from under the plate D, and which under a pressure
of three atmospheres agitates the bath of molten lead so as to produce"
arystallization in proportion as the temperature decreases. In passing
through the molten metal the steam is decomposed and produces oxides

page_text: of lead, antimony, and copper according to the degree of impurity of the
lead. The oxides rise to the surface of the bath, whence they are removed.
When the proportion of lead crystals appears to be sufficient the current
of steam is stopped by closing the cocks C, and the spouts F are opened
so as to allow the molten portion of the lead in which is concentrated
the greater proportion of the silver to flow into the ingot moulds G, G,
by means of a shoot J turning on a pivot, as shewn. As soon as all the
lead is run out the spouts F are closed. While the crystallization was
proceeding in the vat A. a fresh charge of lead has been melted down
in the cauldron H equal in quantity to that run into the moulds, and
having a per-centage of silver approximating as nearly as possible to
that of the crystals in the vat A. This charge is then run down into
the vat A and melts the crystals there formed. Steam is then again
introduced, and the before described operation is repeated resulting in
the production by gradual decrease of the per-centage of silver of merchant
lead on the one hand and on the other hand of lead ready for the cupelling
process. The duration of each operation for 12 to 13 tons of argentiferous
lead is about from 2 to three hours.
Having thus described the nature of this Invention, and in what
manner it is to be performed, as communicated to me by my foreign
correspondents, what I claim is, the before described process of and
apparatus for refining and desilvering lead by means of steam.
In witness whereof, I, the said Charles Denton Abel, have hereunto
set my hand and scal, this Tenth day of May, in the year of
our Lord One thousand eight hundred and seventy.
CHA³. D. ABEL. (L.S.)