A New Apparatus for Extracting Gold from Auriferous Alluvial Earth.
Year: 1892

page_text: Date of Application, 10th Aug., 1892
Complete Specification Left, 10th May, 1893-Accepted, 29th July, 1893
PROVISIONAL SPECIFICATION.
A New Apparatus for Extracting Gold from Auriferous Alluvial
Earth.
I, SAMUEL SIDNEY BROMHEAD of 97 Newgate Street, London, Patent Agent,
(communication) do hereby declare the nature of this invention to be as
follows:-
The extraction of gold is at present effected by a costly and wasteful process.
Our system dispenses with almost all hand labour and greatly increases the
production of gold.
+
It consists in submitting the earth to a continuous soaking and washing, after
which it is passed several times through sieves and thoroughly disintegrated.
To effect this we employ an apparatus consisting of a series of open troughs in
which the earth is first diluted with about double its bulk of water.
The earth is then thoroughly stirred and mixed with the water, after which a
sluice gate at the end of each trough is opened and the mixture passes quickly
through an inclined grating. Any lumps or clots not able to pass through the
grating are broken up and passed through a sieve before being added to the
mixture. The whole is then passed down a steep channel and spread over a series
of sieves or perforated floors.
Any further lumps are here separated and placed in a kneading pan or cast iron
receptacle where they are first crushed and again steeped in water while they are
the same time carefully examined to see if they contain small nuggets or scales of
precious metals.
The sludge is now passed into a receiver in which it is agitated by mechanical
beaters which rotate in it and cause the whole to be thoroughly mixed.
The mixture now passes into small vessels where it is treated with mercury to.
extract the gold. These vessels are so arranged at graduated levels that the
mixture passes through a series of them. At the bottom is a trough to collect the
mercury carried down with the sludge. Horizontal rods carrying stirrers can be
placed over the vessels and kept in motion to prevent any settlement of slime from:
the sludge.
In this way all the metallic parties are brought into contact with the mercury,.
and all the gold is taken up by it. It is then only necessary to separate the gold.
from the mercury, which is effected in the usual way.
The apparatus can be varied in the arrangement of its parts according to the
nature of the earth or the gradient deemed to be requisite.
1
A100
S. S. BROMHEAD.
COMPLETE SPECIFICATION.
A New Apparatus for Extracting Gold from Auriferous Alluvial
Earth.
I, SAMUEL SIDNEY BROMHEAD of 97 Newgate Street, London, E.C. Patent.
Agent (communication from Jean Arnandin & Co. Contractors of Bordeaux,
Department of the Gironde, in the Republic of France) 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:―
The object of this invention is to facilitate the extraction of gold from auriferous.

page_text: The extraction of "gold is at present effected by a costly and wasteful process.
Our system dispenses with almost all hand labor, and greatly increases the
production of gold. It consists in submitting the earth to a continuous soaking
and washing, after which it is passed several times through sieves and thoroughly
disintegrated.
I will now refer to the accompanying drawings of the apparatus, in which :-
Fig. 1. shews a side view of the apparatus. This view is continued at Fig. 1 on
page 2, from where it leaves off on the right of page 1.
Fig. 2. shews a plan view of Fig. 1. This view is continued at Fig. 2 on page 2,
from where it leaves off on the right of page 1.
Fig. 3. shews a sectional view at A, B, (Fig. 2). This section is given in order
to shew the action of the truck W, which carries the auriferous earth to the
troughs, as well as the inclinations and positions of the other parts.
Fig. 4. shews a view of the kneading or grinding apparatus.
The operation is commenced by diluting the earth containing the metal with
about double its bulk of water. This preparation is made in the open troughs A¹
and care is taken to stir the mixture thoroughly.
After this a sluice gate D, at the end of each trough is opened and the mixture
passes quickly through an inclined grating C, after which the residue in the
troughs A is also placed on the gratings C, and the lumps which are too large to
pass through, are thrown on to the sloping floor X between the troughs, where
they fall on to the floor B².
The mixture which has passed through the grating C, falls through the steep
channel F, on to a series of sieves or perforated floors E, and the lumps which do
not pass through these sieves, are withdrawn and thrown on to the floor B'. The
sludge which has now fallen into the trough B' is next passed into an inclined
duct P, from which it passes into a further series of sieves E', (page 2). If some
lumps still remain on the sieves E', they are placed in the receptacles H at the ends
of the sieves, and taken to the kneading or crushing apparatus I, (Fig. 4) which I
will now proceed to describe. This kneading apparatus I is composed of an
ordinary large cast iron receptacle which revolves horizontally. It has a horizontal
arm which supports the crushers employed for separating or breaking the lumps
which are withdrawn from the floor B, and the receptacles H.
:
The crushers are operated in the usual way by cranks or pulleys.
After being crushed these lumps are again steeped in water, and at the same
time carefully examined to see if they contain any small nuggets or scales of
precious metal.
The sieves are constructed of a mesh from 0.002 millimetres upwards as the
operation proceeds and are furnished with brushes which are operated by suitable
mechanism and which clean them, so preventing any clogging and enabling the
mixture to run through.
After these manipulations the mixture of crushed mineral earth, which has
passed through the sieves E', runs down the inclined plane N, into a receiver G.
This receiver has a rod passing horizontally along it, which is put in motion by
two crank handles V, placed one at each end as shewn, and which actuate a fly-
wheel Q. Branches similar to R, and with flappers attached to them are fitted
to U and these are continually rotated to prevent any settling of the mixture.
If desired a motor of any sort can be employed for turning these beaters.
S, is a watergate employed to regulate the running off of the mixture along the
passage T. The second phase of the operation now. commences, which consists of
treating the mixture with mercury.
The passage T, leads the mixture into the first vessel J, from where it falls from
vessel to vessel, as it fills them until it reaches the bottom trough J. All these
vessels J of which there may be any number contain mercury, which collects and
retains the gold from the mixture as it passes down. The bottom trough J¹ serves
to collect any mercury which may escape from the upper vessels J.
To enable the gold to mix quicker with the mercury, horizontal rods K carrying

page_text: stirrers L, can be placed over the vessels, on the sides M and kept in motion;
this also prevent any settlement of slime from the sludge.
In this way all the metallic particles are brought into contact with the mercury,.
and all the gold is taken up.
To clean the apparatus and carry away the earth, water can be passed down it.
After this cleansing it is only necessary to withdraw the mercury and gold which
is done by lifting away the rods K and flappers L and lifting out the vessels J ; the
gold and mercury can then be separated in the usual way.
The parts O represent passages to enable persons to get at the apparatus.
The apparatus can be varied in the arrangement of its parts according to the
nature of the earth or the gradient deemed to be requisite, and the various parts.
can be made of any suitable materials.
Having now particularly described and ascertained the nature of my said inven--
tion I declare that what I claim is :-
1. A series of troughs on an inclined plane, closed by a sluice gate and grating,.
the said troughs being fed by means of a raised feeding way, along which run
trucks or wagons as herein described and set forth.
2. A series of sieves of the same number as the abovementioned troughs gratings.
and inclined planes as herein described and set forth.
3. Two or more large sieves each furnished with brushes operating mechanically,
for cleaning the sieves and facilitating the running through of the clots and lumps,
and a channel for conducting the mixture on to the above sieves, as herein
described and set forth.
4. Agitators arranged at the lower extremity of the large sieves together with.
a series of troughs arranged in cascade, in which suitable mixers or stirrers are
employed, the whole being operated and arranged as herein described and set.
forth.
5. The combination of parts forming the entire apparatus for extracting gold.
from auriferous alluvial deposit, as herein described and set forth.
Dated this
S. S. BROMHEAD,
97, Newgate Street, E.C., Agent for Applicant.