A NEW OR IMPROVED PROCESS FOR SEPARATING THE ZINC FROM THE ARGENTIFEROUS ALLOYS OBTAINED IN THE SEPARATION OF SILVER FROM ARGENTIFEROUS LEAD BY MEANS OF ZINC, AND IMPROVEMENTS IN THE FURNACES EMPLOYED FOR THAT PURPOSE
Year: 1868

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
SEPARATING THE ZINC FROM THE ARGENTIFEROUS ALLOYS OBTAINED IN THE
SEPARATION OF SILVER FROM ARGENTIFEROUS LEAD BY MEANS OF ZINC,
AND IMPROVEMENTS IN THE FURNACES EMPLOYED FOR THAT PURPOSE."―A
communication from abroad by Hilarion Roux, of Marseilles, in
the Empire of France, Merchant.
Sealed the 18th September 1868, and dated the 25th July 1868.
COMPLETE SPECIFICATION filed by the said Charles Denton Abel
at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 25th July 1868, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
5 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, do hereby declare the nature
of the said Invention for "A NEW OR IMPROVED PROCESS FOR SEPARATING

page_text: "
THE ZINC FROM THE ARGENTIFEROUS ALLOYS OBTAINED IN THE SEPARATION OF
SILVER FROM ARGENTIFEROUS LEAD BY MEANS OF ZINC, AND IMPROVEMENTS IN THE
FURNACES EMPLOYED FOR THAT PURPOSE,' a communication to me from
abroad by Hilarion Roux, of Marseilles, in the Empire of France,
Merchant, 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 accompanying Sheet of Drawings,
and to the figures and letters marked thereon, that is to say:-
This Invention consists (when the argentiferous alloy has been
obtained by Parkes' process in the separation of silver from lead by
zinc) in submitting the said alloy to successive liquation processes so
as to remove therefrom the greater portion of the lead combined
therewith. This product broken up into small fragments and mixed
with its own weight of litharge is thrown on to the bed of a reverberatory
furnace.
This furnace is shown on the accompanying Sheet of Drawings, in
which Figure 1 shows a longitudinal section, and Figure 2 shows a
transverse section on line X, X, Figure 1.
The bed A of this furnace rests upon two cast-iron plates B, B¹, made
to incline towards each other in the centre. It is formed of fire-bricks
cemented together by a paste composed of fire-clay and powdered
calcined bones, or it may be formed by placing on the plates a mixture
of fire clay and graphite. The before-mentioned alloy having been
charged into the furnace it is covered with a small quantity of litharge,
and it is heated to a dark red heat. The reactions then commence; one
portion of the litharge is soon reduced by the zinc, which is transformed
into oxide which remains floating in the molten mass, while the lead
.produced absorbs all the silver and is caused to run off through an outlet
passage into a receptacle placed outside the furnace to receive it. As
soon as the running off of the lead ceases the reaction is complete, and
the aperture of the outlet passage is closed. The furnace is then well
heated so as to liquify perfectly the litharge, as also the oxide of zinc
and all foreign matters, such as the oxides of copper, iron, and antimony,
which dissolve. The outlet passage is then again opened, and the
remaining quantity of lead is run off, the arrival of the litharge in the
passage indicating that all the lead has been eliminated. The litharge
is then allowed to flow off separately either on to the floor of the work-
shop or into boilers arranged to receive it. The rich lead is then

page_text: subjected to the cupellation process, while the impure litharge is treated
in the cupola furnace for separating the lead contained therein. In cases
where the argentiferous alloy contains very large proportions of zinc
it is advisable to increase the dose of litharge in order that the latter
may be present in sufficient proportion to perfectly dissolve the oxide
of zinc and to form a sufficiently liquid compound to allow the globules
of lead to traverse it readily.
Having thus described the nature of this Invention, and in what
manner the same is to be performed, as communicated to me by my
foreign correspondent, what I claim is,―
First. The above described process for separating the zinc from
argentiferous alloys of lead.
Second. The before described arrangement of the bed of the rever-
beratory furnace irrespective of dimensions and external form of the
furnace.
In witness whereof, I, the said Charles Denton Abel, have here-
unto set my hand and seal, this Twenty-fifth day of July,
in the year of our Lord One thousand eight hundred and sixty-
eight.