An Improved Method of Smelting and Recovering Metals from Ores and Dross.
Year: 1886

page_text: Date of Application, 5th Nov., 1886
Complete Left, 29th Aug., 1887
Complete Accepted, 4th Nov., 1887
An Improved Method of Smelting and Recovering Metals from
Ores and Dross.
I, JAMES NICHOLAS of Elizabeth Cottage, Ilford, in the County of Essex, Manu-
facturing Chemist, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an improved process for the reduction of certain metals
such as gold, silver, or tin from their ores, and from the refuse dross, scoriae or
similar material produced by reducing or refining works, and for the treatment of
pyritous material (especially that of tin pyrites) and its refuse, dross, scoriae &c.,
which are complex combinations of oxides, silicates sulphides &c.
My invention is designed to so disintegrate and oxidize the material under treat-
ment so that the metals may be recovered in the usual way by flux.
The material is first submitted to the action of heat, in, say, an ordinary rever-
beratory furnace, and when at a suitable temperature, say red heat, it is withdrawn
and plunged in its heated condition into a cold bath of any strong alkali or any
strong chloride in solution. This causes a disintegration and oxidation of the material
under treatment, and at the same time secures an intimate admixture of it and the
reagent used in solution. Decrepitation of the entire material cannot be expected
to ensue from this treatment, but what has not yielded will be rendered so friable
that it may easily be pulverised by any of the ordinary disintegration, grinding, or
stamping machinery used for such purposes. If desirable that the material be
submitted to a further oxidising and decrepitating influence, then the further
disintegration and oxidation can be effected conjointly by the ordinary process of
weathering, that is by its exposure in its calcined and chemically prepared condition
(as before stated) to the action of the weather in an exposed place.

page_text: When the material is prepared by either of the said means, it is dried, intimately
mixed with a suitable flux, and subjected to a sufficiently strong heat to reduce the
same. Then practically the whole of the metal present will be recovered in a condition
of great purity. It is, however, very necessary in the case of tin, that the furnace or
reducing operation be so conducted that a minimum quantity of atmospheric air or
free oxigen be allowed to come into contact with the mass under treatment.
For the effectual carrying out of this, I may so modify the construction of the
furnace that the air is practically occluded.
I may reconstitute my bath by any known process, and may recover by precipi-
tation or otherwise any other matter of value that may be in solution.
Dated this 5th day of November 1886.
FELL & WILDING,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Method of Smelting and Recovering Metals from
Ores and Dross.
JAMES NICHOLAS of Elizabeth Cottage Ilford, Essex Manufacturing Chemist
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 relates to an improved process for the reduction of certain metals
such as Gold Silver or Tin from their Ores and from the refuse dross scoriae or
similar material produced by reducing or refining works and for the treatment of
pyrites and pyritous material and their refuse dross scoriae &c.
My invention is designed to so disintegrate oxidise and make diverse combinations
of the material under treatment that the metals may be more easily and completely
recovered therefrom in the usual way by flux or otherwise.
The material is first submitted to the action of heat in say an ordinary reverberatory
furnace and which at a suitable temperature say red heat it is withdrawn and plunged
in its heated condition into a cold bath consisting of a strong or a nearly saturated
solution of any alkali or Chloride or mixtures of them.
Disintegration and oxidation of the material under treatment is thus caused and at
the same time an intimate admixture of the material and of the re-agent used in the
solution is secured, thus bringing about a partial decomposition of the material under
treatment and the formation of fresh compounds which are more easily treated by the
subsequent processes and so enable a larger proportion of metal to be recovered.
Decrepitation of the entire material cannot be expected to ensue from this treat-
ment but what has not yielded to it will be rendered so friable that it may easily be
reduced to powder by any of the ordinary disintegrating or grinding machines
without resort to the ponderous stamps and stamping machinery now in use.
After the material has been thus prepared it is in a finely divided state. It is
then intimately mixed with a suitable flux and subjected to a sufficiently strong heat
to reduce the same.
The result will be that practically the whole of the metal present will be recovered
in a condition of great purity.
In the case of pyrites or pyritous ores or of ores containing more than one of the
above metals the mixed metal or alloy so recovered can be easily and completely
parted or separated by any known process.
It is however necessary in the case of Tin that the furnace or reducing operation
be so conducted that a minimum amount of atmospheric air or free oxygen be allowed
to come into contact with the mass under treatment.
For the effectual carrying out of this process I may so modify the construction of
the furnace that the air may be practically occluded from the material which is being
fluxed, by converting it into a muffle furnace which is effected by a furnace

page_text: constructed according to the accompanying drawing, such a furnace resembling the
ordinary reverberatory type but which is capable of being at pleasure converted into
a sort of muffle furnace as will be understood by the following explanation.
The letters A in the drawing show the furnace in longitudinal section-B is the
ash pit C are the furnace bars-the letters E show the reverberatory, the bed of
which L, is composed of any refractory material, and underneath L is a strong iron
dish K J is a damper in the chimney G controlling the reverberatory E. D is a flue
running under the reverberatory into chimney G and is controlled by damper I.-
N are orifices in the brickwork with movable caps used to clean out flue D-M is the
hopper through which the ore &c. is shot into the reverberatory-P is the midfeather
in the chimney G to prevent the draughts working adversely.
It will be seen that when the damper I is pushed in, and the damper J is drawn
out that the furnace will act as a reverberatory; and that when J is pushed in and I is
drawn out that the reverberatory is heated from below by the flue D and that practi-
cally the air will be occluded from the material that is being treated in consequence
of the reverberatory working under similar conditions to that of a muffle furnace.
I may reconstitute my bath by any known process and may recover by precipi-
tation or otherwise any matter which may be held in solution.
Having now particularly described and ascertained the nature of my invention
and in what manner the same is to be performed I declare what I claim
to be
Firstly, as to the ores of gold silver or tin and as to the refuse dross scoriae or
similar material of or from the ores in question a mode substantially as described of
ready inexpensive and thorough disintegration and oxidation and in the process of
such disintegration and oxidation the production of combinations which admit of the
metal contained in the ores &c. being more easily and completely recovered by
means of fluxing or otherwise.
Secondly, as to pyrites, or pyritous ores, and as to ores containing more than one
of the above metals-and as to the refuse dross scoriae or similar material of or from
the same a like mode of disintegration and oxidation and the production of com-
binations which admit of the various metals contained in such pyrites, pyritous, or
compound ores &c. being more easily and completely recovered by means of fluxing
or otherwise.
Dated this the 24th August 1887.