An Improved Process for the Extraction of Gold and Silver from their Ores.
Year: 1895

page_text: Date of Application, 28th Sept., 1895
Complete Specification Left, 25th July, 1896-Accepted, 26th Sept., 1896
PROVISIONAL SPECIFICATION.
An Improved Process for the Extraction of Gold and Silver from
their Ores.
FRANKLIN CLAY MAY 10 Sterndale Road West Kensington W., London,
Exhibitor, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved process for the extraction of gold and silver
from their ores. It has for its object the destruction of, or combination with
deleterious compounds which occur in some gold and silver ores. I mix with the
crushed ore a suitable amount of a weak solution of a hydrated oxide or carbonate
of an alkaline metal, such as caustic soda or carbonate of soda. The hot or cold
solution may be agitated with or simply percolated through the ore. I then wash
the ore with water until the excess of chemicals is removed. By this process of
treatment I decompose sulphates of iron in the ore and dissolve out arsenical and
antimonial compounds. I then treat the ore with quicksilver either on amalgamated
copper plates or in suitable vessels or pans in the usual way.
Dated this 26th day of September 1895.
FRANKLIN CLAY MAY.
COMI LEID DT DUIFICATION.
An Improved Process for the Extraction of Gold and Silver from
their Ores.
I, FRANKLIN CLAY MAY, of 10 Sterndale Road, West Kensington, London, W.:
Exhibitor, 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 :-
My invention relates to an improved process for the extraction of gold and
silver from their ores, and has for its object the removal from the crushed ore by
treatment before amalgamation of deleterious compounds such as sulphides of iron
or arsenical antimonial and cupric compounds which occur in some gold or
silver ores.
To carry my process into effect the ore is first crushed in any usual manner, and
the crushed ore may be treated by leaching with a solution of mixed alkaline
hydrate and carbonate either cold in the case of weakly pyretic ores, or hot in
other cases but preferably in most cases the ore is boiled for about one hour in a
solution containing 5 per cent. of an alkaline hydrate such as caustic soda, aud
5 per cent. of an alkaline carbonate such as carbonate of soda.
The boiling
solution may be agitated with or percolated through the ore, and after one hours
boiling is allowed to stand for at least 24 hours.
In the case of arsenical, copper, or antimonial ores the solution is poured
off or drained away from the ore which is then washed or leached with water
to remove any excess of the chemical solution remaining therein. One washing is
usually sufficient.
These ores are then ready for treatment by amalgamation with quicksilver_ to
collect the precious metals in any usual manuer on plates, in barrels, or paus.

page_text: It will be found that the dissolution of the arsenical, cupric, and antimonial
compounds by my aforesaid preliminary treatment much enhances the ease and
efficiency of the usual treatment by amalgamation preventing the flowing, or
sickening, of the mercury employed in the said amalgamation and giving increased
extraction.
In the case of ordinary ores or ores containing chiefly iron pyrites and
without arsenical or antimonial compounds my solution decomposes the sulphides
of iron, and such ores after treatment with my solution and standing as aforesaid
may be passed at once to the amalgamating pans, barrels or plates, without
draining off the solution or washing unless it is desired and practicable to again use
the solution.
The total amount of my solution used in each case, will vary according to the
"refractory" or "rebellious " character of the ores but may always be used in
excess, in which the partially exhausted can be refortified and used again.
In the absence of carbonate of soda, soda crystals (common washing soda) may
be used in my solution with equal effect care being taken that the necessary amount
of carbonate of soda be present.
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 :-
1st. A preliminary treatment before amalgamation of gold or silver ores, with a
mixed solution of alkaline hydrates and alkaline carbonates.
2nd. A treatment of gold or silver ores before amalgamation consisting of the
boiling of the crushed ore for at least one hour in a solution of mixed alkaline
hydrates and carbonate, such as caustic soda and carbonate of soda and the
after digesting of the ore for at least 24 hours in said solution substantially as
described.
3rd. The washing and draining off of the solution from the ore sludge of arsenical
cupric or antimonial ores, after boiling and digesting before passing same to
amalgamation substantially as described.
4th. The composition of the solution for a preliminary treatment of gold and
silver ores, consisting of equal parts by weight of alkaline hydrate and carbonate
such as 5% of caustic soda and 5% carbonate of soda with 90% of water,
substantially as described.
FELL & JAMES,
1 Queen Victoria Street, London, E.C., Agents for the Applicant.