An Improved Process for Treating Refractory Ores.
Year: 1896

page_text: Date of Application, 3rd June, 1896-Accepted, 27th Feb., 1897
COMPLETE SPECIFICATION.
An Improved Process for Treating Refractory Ores.
I, ERNEST GOVETT of Broken Hill Chambers No. 31 Queen Street Melbourne
in the Colony of Victoria (but temporarily residing at Adelaide in the Province
of South Australia) Mining Agent 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 treatment of refractory or
rebellious silver lead orcs for the extraction of the silver contained in such ores
and more particularly those termed "sulphide" or "sulphuretted "ores which
contain in addition to sulphur zinc, arsenic, antimony or other compounds or
components alone, or in combination, or any of them.
For the purpose of this invention the ore is first crushed to a very fine powder
or a fine grade by any suitable or convenient means, either wet or dry, and by any
suitable disintegrator or mill. It is then dried if necessary, and has added to it
(if necessary) a small percentage of charcoal of say one per centum to four per centum
by weight of the charge of ore. The crushed ore is then amalgamated with lead,
by being passed into a bath of molten lead, whereby the silver is mechanically
separated from the ore, the charcoal assisting to prevent the oxidation of the lead.
By this amalgamation the greater portion, say 45 to 70 per cent. of the metallic
silver contained in the ore is removed, when the amalgam of lead and silver is
withdrawn from the bath by the usual means in the form of bullion.
remainder of the material in the bath, consisting of say from 1 to 10 per cent. of
the molten lead and the remainder of the silver which has not been removed in
the amalgamation, together with the lead sulphides and impurities, comprising
sulphur, zine and arsenic, not already volatilized by the heat of the bath, are then
concentrated, to remove the zine and gangue if any is present and any other
substances, after which the concentrates are smelted and the rest of the silver
recovered by ordinary methods.
The
The lead bath is re-charged with molten lead after each operation by any
suitable means or apparatus.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. The herein described process for the treatment of sulphide or sulphuretted
silver lead ores, consisting in reducing the ore to a fine grade; then amalgamating
the charge in a lead bath and withdrawing the amalgam of silver and lead as
bullion; then concentrating the remainder of the charge including a portion of the
molten lead, a part of the silver, together with the lead sulphides, and impurities
not already volatilised by the heat of the bath, for the purpose stated; and finally
smelting the concentrates to recover the remainder of the silver, substantially as
herein described.
2. In the treatment of sulphide or sulphuretted silver lead ores, the amalgamation
of the ore in a lead bath for the removal of a portion of the silver, in combination
with a subsequent concentration of the remainder of the charge, including a portion

page_text: of the molten lead, a part of the silver, together with the lead sulphides, and
impurities not already volatilised by the heat of the bath, to fit the ore for further
treatment by ordinary methods.
Dated this 24th day of April 1896.
J. E. EVANS-JACKSON & Co.,
Agents for the Applicant.