Improvements in the Extraction of Precious Metals from their Ores.
Year: 1891

page_text: Date of Application, 2nd Sept., 1891
Complete Specification Left. 1st June, 1892-Accepted, 6th Aug., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Extraction of Precious Metals from their Ores.
WILLIAM HENRY MARTIN Assayer, 183 Kings Road Chelsea S.W. WALTER
PETHYBRIDGE Assayer, 183 Kings Road Chelsea S.W. do hereby declare the
nature of this invention to be as follows:-
Our invention relates to the extraction of the precious metals such as gold, silver,
and other rare metals, from refractory and other ores, or gold bearing quartz, which
we effect in the following manner. In the first place, we pulverize the ore, and
place the powder in a cylindrical or spherical shaped iron vessel, having trunnions,
and chilled iron or steel round or elliptical balls, or solid cylinders inside the vessel.
One end or side of the vessel to be moveable, with gland to allow the passage of
compressed air or steam charged with the following chemical substances the same
as in the iron vessel mixed with the ore. The charge is composed of pulverized
ore, mixed with one or more of the following chemical substances, viz. ammonium
cyanide, water, ammonium chloride sodium hypochlorite liquid ammonia, ammonium
formate, formic acid, hydrocyanic acid and copper sulphate. The vessel to contain
also a small quantity of mercury to amalgamate the gold and silver.
The vessel has also an arrangement for applying electricity with high tension to
the ore, to assist in the amalgamation of the gold & silver.
The vessel is caused to revolve horizontally or vertically as required according
to the nature of the ore treated, while a current of electricity is transmitted through
the contents of the vessel, one pole being in contact with the mercury and the other
pole in contact with the ore and chemicals.
The contents of the vessel after running the required time, is taken out, and the
mercury separated from the ore, and retorted in the usual way with the addition of
a small quantity of ammonium cyanide or other chemicals as above mentioned
mixed with the amalgam in the retorts to help the freeing of the gold.
Dated this 1st day of September 1891.
WILLIAM H. MARTIN.
WALTER PETHYBRIDGE.
COMPLETE SPECIFICATION.
Improvements in the Extraction of Precious Metals from their Ores.
WILLIAM HENRY MARTIN of 183 King's Road Chelsea in the County of
Middlesex and WALTER PETHYBRIDGE of 183 King's Road Chelsea in the
County of Middlesex Assayers & Metallurgists 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 extraction of precious metals, such as gold & silver
& other rare metals from refractory and other ores or gold-bearing quartz which
we effect in the following manner. For this purpose we finely pulverise the ore,
and place the ore in a cylindrical shaped vessel either of iron or wood having
trunnions in which vessel are also placed a number of iron balls. The vessel to
have two manholes in the centre for the introduction and removal of ore and
contents as Fig. I & II c.
The wood or iron vessels are constructed with arrangement for supplying
electricity at high tension to the ore. The arrangement being a hollow steel rod
reaching from one end of vessel to the other with a number of double distributors
or arms screwed into iron collars which are keyed on to the main shaft as 6 by
077

page_text: means of which a continuous or alternating current of electricity at high tension
can be supplied according to the nature of the ore treated. The hollow steel shaft,
has a number of holes drilled on the under side a quarter of an inch in diameter to
allow the passage of compressed air or steam, to pass into the cylinder the rod
having also a gland at (c) to admit of the rotating of the vessel, having also
insulators at D.
The pulverized ore is placed in cylinder and damped with water to the consistency
of cream. The ore is then charged with one or more of the following chemicals
according to the nature of the ore formate of ammonia prussic acid cyanide of
ammonia, ammonia or mercuric cyanide. The vessel may also contain a small
quantity of mercury to amalgamate the gold-viz. for very refractory from 6 to
12 pints of ammonia formate ammonia cyanide, prussic acid & ammonia in equal
parts, & for slightly pyretic ores half the above quantities per ton of ore with a
little mercuric cyanide.
The vessel is then made to revolve at a speed varying from 100 to 500 revolutions
a minute at the same time a continuous supply of air or steam is then forced into
the cylinder varying from two to four atmospheres during the whole of the treat-
ment, and a current of electricity is passed one pole passing through the interior of
the cylinder the other being in contact with the distributors.
By this method the whole of the precious metals are brought into intimate
contact with the solution the cyanogen being liberated dissolves out the whole of
the precious metals in the rebellious ore. The contents of the cylinder after
running the required time (varying from four to six hours) are taken out the
mercury separated and the ore and solution placed immediately on the filtres of
special construction as hereinafter mentioned. The liquid which contains the
precious metals is then placed in vats and the precious metals precipitated by a
current of low-tension electricity upon large carbon plates. The mercury being
retorted in iron retorts for precious metals also.
The filtres used in this method are made of stout wood or enamelled iron with a
perforated filtre place e supported by a column D as in Fig. III & III the under
side of the filtre having two taps through one Fig. III a the air is exhausted which
causes the liquid to run through quickly the liquid is then run off through tap b
and the precious metals are precipitated.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is―
The herein described improved method of extracting gold and other precious
metals from all kinds of ores including slimes & refractory tailings, by agitating
the ore whilst in a finely divided state in a solution of one or more of the following
chemicals ammonia formate ammonium cyanide, ammonia prussic acid or mercuric
cyanide with or without the use of metallic mercury and by the aid of electricity
and compressed air or steam as set forth.
Dated this 31st day of Mar 1899
WILLIAM HENRY MARTIN.
WALTER PETHYBRIDGE.