Improvements in the Method of Treating Refractory Gold and Silver and other Metal-bearing Ores and Materials.
Year: 1896

page_text: Date of Application, 20th Nov., 1896
Complete Specification Left, 29th June, 1897-Accepted, 20th Nov., 1897
Improvements in the Method of Treating Refractory Gold and Silver
and other Metal-bearing Ores and Materials.
I, JOSEPH CAMPBELL, of St. Nicolas College, Randwick, near Sydney, New South
Wales, Consulting Geologist and Chemist, do hereby declare the nature of this
invention to be as follows:-
This Invention of improvements in the method of treating refractory gold and
silver and other metal-bearing ores and materials relates to the elimination from
the ores and materials of all those base substances that prevent the amalgamation
of the gold and quicksilver, and these improvements consist in the particular
method by which such result is attained.
These improvements in the method of treating refractory, gold and silver and
other metal-bearing ores and materials consist in the admission of water-gas (or
in other words gas consisting of equal volumes of mechanically admixed pure Hydro-
gen and Carbonic Oxide) to the ores or materials while roasting in closed chambers
or retorts.
The positive results of this treatmont of the oro or materials by water-gas in
closed retorts or in a closed furnace are:-(a) the ore or material becomes exceed-
ingly friable, much more so than the best roasted quartz from open kilus, and muy
be easily broken by hand, henco the use of lighter stamps is permitted or casier
grinding is effected, (b) that the auriferous particles are changed in form to a
globular or approximately globular condition (the more minute the metallic
particle the more perfect the spheroidal shape) the gold in this spheroidal form is
less acted on by water in the amalgamating process and hence the loss in the form
of float-gold will be reduced to a minimum, (c) the base materials with which the
gold is chemically or mechanically combined or coated, inter alia, Sulphur, Arsenic,
Tellurium, Bismuth, Zinc, Lend, Iron and Copper Pyrites aud Iron Oxide, are
eliminated and leave the gold perfectly free for amalgamation. In addition to
this, by means of flues and suitablo chambers, bye-products may be saved and thus
reduce the cost of treatment.
My method of treating refractory gold and silver and other metal-bearing ores
and materials is not confined to any particular apparatus but may be practised in
any air tight retort or series of closed retorts or single furnace to which water-gas
may be supplied.

page_text: Improvements in the Method of Treating Refractory Gold and Silver
and other Metal-bearing Ores and Materials.
I, JOSEPH CAMPBELL, of St. Nicolas College, Randwick, near Sydney, New South
Wales, Consulting Geologist and 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 the treatment of refractory gold, silver and other
metal-bearing ores and compounds, (hereinafter referred to as ores,") its object
being to eliminate from such ores the contained relatively baser metals or materials
with which the gold or other metal sought may be chemically or mechanically
combined and which would hinder the amalgamation or other appropriate subse
quent obtainment of the metal sought, so as to facilitate such obtainment and
lessen the loss of the metal sought.
To this end, the improved treatment consists in or is characterized by the sub-
jection of the ore (say, by way of example, auriferous ore,) while being roasted,
without access of air, in a closed retort, chamber or furnace, or in a serios thereof,
(hereinafter referred to as "retorts,") to the action of water-gas, which is caused to
circulate through the retort or retorts, by which means the ore is rendered
exceedingly friable, the base metals and materials are carried off as volatile com-
pounds with the constituent gases of the water-gas or are reduced to such a
condition as will parmit of the gold being readily obtained by amalgamation, and
loss in the form of float-gold, during amalgamation, is reduced.
The water-gas omployed is preferably composed of about equal volumes of
hydrogen and carbon mon-oxide, as the action thereof is then the more speedy and
complete due to the conjoint action of such constituent gases, but may also be
employed, though not so advantageously, when the constituent gases are mixed in
other proportions, or when diluted with other gases as in the form known as
"Dowson gas."
In carrying out the improved treatment, there may be used any suitable
arrangement of apparatus in which an assemblage of closed ore treating retorts is
combined with an arrangement of water-gas producing retorts, the ore
treating retorts being so arranged and connected that the cmtents
thereof may be charged from one to another in downward succession,
until eventually withdrawn when sufficiently treated, and that the
water-gas may pass from the water-gas retorts upwardly through the
series of ore freating retorts, from which latter the water-gas and its
volatile compounds with the base metals or materials may escape to an uptake, or
may be led to a series of chambers for the deposit or recovery of the more valuable
of such base metals or materials as bye-products.
The improved treatment may, however, be carried out in any suitable air-tight
retort or series of retorts sufficiently heated according to the nature of the ore
under treatment, and to which the water-gas may bo supplied. The water-gas
may, moreover, be separately manufactured and stored in a gasometer for use as
required.
In some cases, particularly with ores containing antimony, sulphur or arsenic
(but not in the case of telluride ares,) the ore may firstly be roasted in the retorts,
with access of air and without admission of the water-gas, until such of the more
volatile impurities or such proportion thereof as can be so eliminated, have been
eliminated, the ore then being subjected to the herein-described improved treat-
ment in order to complete the elimination and obtain the desired object.

page_text: Though the improved treatment is hereinbefore described with particular refer-
enoc to refractory auriferous oros, it is also, as aforesaid, applicable to ores of iron
and other metals, its application effecting such a sweet roast that the smelting of
the ore will be greatly facilitated.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed, I declare that what
I claim is:-
The improved treatment of refractory gold, silver antl other metal-bearing ores
and compounds, consisting in or characterised by the subjection of the ore or
compound, while being roasted, without access of air, in a closed retort or retorts,
to the action of water-gas, substantially as heroinbofore described.
Dated this 20th to 100
DAY, DAVIES & HUNT,
Chartered Patent Agents,
321 High Holborg, London, W.C., Agents for the Applicant.