A New or Improved Process and Means for Treating Quartz Containing Gold, Silver, and other Metals.
Year: 1893

page_text: Date of Application, 12th Dec., 1893
Complete Specification Left, 11th Oct., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
A New or Improved Process and Means for Treating Quartz
Containing Gold, Silver, and other Metals.
I, RICHARD PEARSON of 154 Gresham House in the City of London, Mining
Agent, do hereby declare the nature of this invention to be as follows:-
:-
Heretofore machines known as stamps or stamp batteries have generally been
employed for crushing quartz, ore, and other metal ores whereby a very great loss of
energy and wear and tear of the machinery have been occasioned, while by the ordinary
stamps or stamp battery a good deal of what is technically known as "float gold,"
other metals or metalliferous ores in a state of fine subdivision (hereafter for the
purposes of this description referred to as "gold") is lost because the crushing by
continuous blows of hard quartz rock to fine sharp powder, always tends to separate
into very fine particles, portions of the metals, in spite of the malleability of the
same, whereas by my invention these objections are materially reduced or over-
come, while at the same time the quartz is pulverized in a more efficient manner
than heretofore, and the production of float-gold is greatly diminished.
known that finely divided gold when heated to a temperature much below its
actual melting point tends to agglomerate and to become denser, thus in the
annealing of gold "cornets in the assay of bullion, this extremely fragile metal
is rendered hard and tough by heating it to redness. A further example is the
welding together of precipitated gold-a brown powder in a state of very fine
subdivision-this on being well heated and struck with a hammer becomes welded
to a solid mass without having undergone fusion. The melting point of gold
is 1070° C. to 1100° C. A full red heat is 900° C. My invention is based on
these facts.
"
It is
According to my invention I break the quartz into pieces of about equal size,
by submitting it for example to the action of a stone breaking machine the broken
pieces of quartz are then fed into a furnace by a hopper or otherwise where they
are heated to a dull red heat, although in some cases it may be found desirable to
increase the heat above these limits. The heat at which the gold agglomerates
and the fracturing of the ore best takes place varies with different ores and may
be less or considerably greater than a red heat. Immediately after removal from
said furnace, the quartz ores and the like thus heated are quenched by depositing
them in a tank containing water kept at a suitable temperature. After removal
from the tank the quartz treated in the manner before described is passed between
rolls, or other crushing medium, and thereby crushed to fine powder the rolling
grinding action being so effected as to open out the quartz without too greatly
dividing up the contained gold. I do not limit myself to any particular machinery
to carry my new or improved process into effect but I have found that a revolving
furnace arranged at an angle or sufficiently out of the horizontal line, for the
quartz to travel by gravitation and rotation from one end to the other answers the
purpose of my invention well, so that when the same (the quartz) ores are
sufficiently heated the roasted quartz may be run out into the water tank at the
end opposite to that at which it entered, or the broken quartz might be carried in
a bucket suspended from a travelling trolley to a furnace into which it is lowered
and when sufficiently roasted therein, it is removed therefrom into the trolley for
conveyance to the tank; or other means for roasting and quenching the said quartz
may be adopted.
In a tubular furnace such as that before referred to the heating will tend
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page_text: Second-To break up the large pieces of rock along the vein divisions and the
interstices of the crystals and especially along the lines of contained metalliferous
deposits, and thus to render the heating uniform.
Third-The jolting and continued turning over of the ore, while under heat,
will have a beneficial tendency in further agglomerating the gold. After a full
red heat is obtained the ore may be quenched, the result of which is to further split
up the rock and by softening it (by producing innumerable fractures of the
crystalline rock in all directions) necessitates a far smaller amount of crushing and
this again diminishes the production of float gold, to a great extent.
By the above process and means for carrying out the aforesaid process it will be
understood that without having the effect on the quartz of a complete oxidising
roasting the preliminary heating tends to reduce, and even to eliminate sulphurets,
arseniurets, and other extraneous matters, and where large quantities or amounts of
these substances are present such treatment would be especially appreciated, and
an approximately complete oxidising roasting may be obtained if desired by means
of increased heated air supply whilst the ore is in the furnace. The waste heat
from the furnace can if desired be utilized, for heating feed water for boilers, or
other useful purposes, and the quenching water when heated by the ore can be
utilized in a similar manner.
Dated this 12th day of December 1893.
BREWER & SON,
London and Leeds, Agents for Applicant.
COMPLETE SPECIFICATION.
A New or Improved Process and Means for Treating Quartz
Containing Gold, Silver, and other Metals.
1, RICHARD PEARSON, of 154, Gresham House, in the City of London, 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, that is to say :-
What are well-known as "stamps" or stamp batteries have generally been
employed for crushing quartz, ore, and other hard mineral ores and substances.
By their use, however, a very great waste of power and wear and tear of the
machinery have been occasioned, while moreover by the ordinary stamps or stamp
battery a considerable proportion of what is technically known as "float gold,'
and other metals or metalliferous ores in a state of fine subdivision, (such other
metals or ores being hereinafter for the purposes of this description referred to as
gold") is lost for the reason that the crushing of hard quartz rock to fine sharp
powder by continuous blows always tends to separate into very fiue particles,
portions of the metals, in spite of the malleability of the same. By my present
invention, these objections are overcome or materially reduced, whilst at the same
time the quartz is pulverized in a more efficient manner than heretofore, and the
production of float gold is greatly diminished.
66
"
It is known that finely divided gold when heated to a temperature much below
its actual melting point, tends to agglomerate and to become denser, thus in the
annealing of gold "cornets in the assay of bulliou, this extremely fragile metal
is rendered hard and tough by heating it to reduess. A further example is the
welding together of precipitated gold in the form of a brown powder in a state of
very fine subdivision, which, on being well heated and struck with a hammer
becomes welded to a solid mass without having undergone fusion. The melting
point of gold is about 1,100° C., whilst a full red heat is about 900° C. My
present invention is based on these facts.
According to my invention, I first break the quartz into pieces of about equal
size, (say, about 2 inches to 2 inches), by submitting it, for instance, to the action

page_text: of a stone breaking machine. These broken pieces of quartz are then fed into a
furnace, by a hopper or other suitable means, where they are heated to a dull red
heat. Or, in some cases it may be found desirable to increase the heat above this
limit. The heat at which the gold agglomerates, and the fracturing of the ore
best takes place, varies with different ores, and may either be less or considerably
greater than a red heat. Immediately after leaving the furnace, the quartz thus
heated, is quenched by discharging it into a tank containing water. After removal
from the tank, the quartz treated in the manner described becomes so friable that
it can be easily broken with very little force, and it is then passed between rolls or
other crushing devices, and crushed to fine powder. I do not confine myself to
any particular form of machinery to carry out my invention as above described,
which may be varied more or less as may be found desirable. For instance, a
revolving furnace may be used, arranged at a sufficient angle with the horizontal
line, so that during its rotation the quartz travels by gravitation from one end to
the other, so that when the contents are sufficiently heated, they can be discharged
into a water tank at the end opposite to that at which they entered. Or, the
broken quartz may be carried in a bucket suspended from a travelling trolley to a
furnace into which it is lowered, and when sufficiently roasted therein it can be
removed therefrom, and conveyed to the water tank; or other equivalent means
for roasting and quenching the said quartz may be adopted.
The heating in a furnace, as described, will tend :-
First, to agglomerate the finely divided gold.
Second, to break up the large pieces of rock along the vein divisions and the
interstices of the crystals, and especially along the lines of contained metalliferous
deposits and thus render the heating uniform.
Third, the jolting and continued turning over of the quartz or ore, whilst under
heat, will have a beneficial tendency in further agglomerating the gold. After
sufficient heat (about a full red heat), has been obtained, the ore may be quenched,
as described, the result of which is to further split up the rock and by the resulting
softening (by producing innumerable fractures of the crystalline rock in all
directions) a far smaller amount of crushing is required, and this again diminishes
the production of float gold to a great extent.
The above described process, moreover, without having the effect on the quartz
of a complete oxidizing roasting, tends to reduce, and even to eliminate sulphurets,
arseniurets, and other extraneous substances, and where large quantities of these
substances are present, such treatment would be especially appreciated, and an
approximately complete oxidizing roasting may be obtained if desired, by means
of increased heated air supply whilst the ore is in the furnace.
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 process for treating quartz containing gold, silver, or other metals,
consisting in subjecting such quartz reduced to pieces of suitable size, to such a
heat that, when it is quenched in water, it becomes so friable that it can be very
readily crushed and reduced to powder and the gold obtained, the production of
float gold being greatly diminished, substantially as described.
2. For the purpose of carrying out the process described and claimed in the first
claim, the use of an inclined revolving heating furnace, down which the quartz, in
fragments of suitable size, passes, and is discharged at the lower end, into a vessel
containing water, substantially in the manner, and for the purpose described.
Dated this 11th day of October 1894.
EDWARDS & Co.,
65 and 66, Chancery Lane, London, Agents for the Applicant.