Improvements in the Wet or Hydro-metallurgical Method of Ex- tracting Gold from Crushed or other Finely Divided Auriferous Material.
Year: 1887

page_text: COME DEIN DEBUITIGATION.
Improvements in the Wet or Hydro-metallurgical Method of Ex-
tracting Gold from Crushed or other Finely Divided Auriferous
Material.
We, JAMES COSMO NEWBERY, of the Technological Museum, Melbourne, in the
Colony of Victoria, Bachelor of Science, and CLAUDE THEODORE JAMES VAUTIN, of
Jackson Street, St. Kilda, in the said Colony, Metallurgical Engineer, 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 :-
Our invention consists of certain improvements in what is known as the wet or
hydro-metallurgical method of extracting gold from crushed or other finely divided
auriferous material.
This "wet" or hydro-metallurgical method may be said to consist-first-Iu
submitting the auriferous material under treatment to the action of such reagents
(either in form of a solution or gas) as circumstances may direct, that will so react on
the gold sought for, as to form soluble salts of it, in which condition it may be leached
or dissolved out from material under treatment. As to the first or dissolving part,
it has been ascertained that the reagents used to convert the gold sought for into a
soluble form operate more quickly when they are applied under pressure. Thus, as
an example, Chlorine either when applied in form of gas or in solution, under a pressure
greater than that of the atmosphere, combines with and converts the gold into a
chloride, more rapidly than when applied under normal atmospheric pressure. Now
hitherto when chlorine has been used under pressure greater than that of the atmosphere
such pressure has been obtained by providing great excess of chlorine gas beyond that
necessary to combine with the gold, and this excess is utterly valueless in the process
except as a means of producing pressure. Now, we substitute air under pressure
ustead of the excess of chlorine as a means of producing necessary pressure and this
pressure we obtain by means of any known air compressing device such as an air pump.
When chlorine is used, great advantage is gained by employing an air pressure of about
our atmospheres, for thereby any chlorine that may exist in form of gas in the vessel
ontaining the material under treatment, will be liquefied and dissolved in the water
dded, in which condition we find its action greatly accelerated.

page_text: Secondly. One of the greatest objections to the hydro-metallurgical method bitherto
has been the length of time required for the draining off, filtering, or removal of the
solutions from the material under treatment. Now we greatly reduce the time by the
application of an aspirator, and preferably by a vacuum pump as such aspirator, to
the lower portion of the filter containing such material in order to draw or suck
the solution through the filter-bed and out of the filter. We prefer a vacuum pump
as an aspirator because we find that a jigging motion is thereby given to the material
while the solution is being withdrawn or sucked out, which motion prevents the material
from setting too tightly on the filtering medium.
Having obtained the auriferous solution from the auriferous material in the manner
herein set forth we proceed to extract the gold therefrom in the following manner
although we do not claim this method of extraction as part of our invention. We
provide thick or deep beds of rough charcoal, that is, charcoal in pieces and not in
dust, and by preference we arrange such charcoal beds in the form of narrow columns
contained in earthenware pipes. Through these columns we pass the auriferous
solution, which is thereby rapidly decomposed and deposits its gold on the charcoal,
from which we obtain it by burning as is well understood.
Hag now particularly described and ascertained the nature of our said invention,
and in what manner the same is to be performed, wo declare that what we claim is :-
1. The application of air pressure in the wet or hydro-metallurgical method of
extracting gold from crushed or other finely divided auriferous material, for the
purpose of accelerating the action of the chlorine and other reagents used substantially
as herein described and explained.
2. The application of an aspirator for the purpose of sucking the auriferous solution
through the filtering medium and out of the filter-such aspirator being preferably in
the form of a vacuum pump so as to give a jigging motion to the material under
treatment, substantially as herein described and explained.
Datad this Tightsouth bay of Bahruary 1887