An Improved Process of or Means for Extracting or Recovering Metals from Ores or other Metal Bearing Bodies.
Year: 1891

page_text: Date of Application, 9th June, 1891
Complete Specification Left. 11th Apr., 1892-Accepted, 9th Sept.. 1892
PROVISIONAL SPECIFICATION.
An Improved Process of or Means for Extracting or Recovering
Metals from Ores or other Metal Bearing Bodies.
We, WILLIAM NOAD, of 38, Eversleigh Road, Upton Park, in the County of
Essex, Chemist and Assayer, CHARLES MINNS, of 12, Victoria Street, in the
City of Westminster, Civil Engineer, and PHILIP HORDLE STEVENS, of Wool
Exchange Buildings, Coleman Street, in the City of London, Land and Mining
Agent, do hereby declare the nature of this invention to be as follows:-
-
This invention relates to an improved process of or means for extracting or
recovering metals, especially the precious metals, from ores, matrices, tailings, or
other metal bearing bodies.
The ore
or metal bearing body to be treated may be crushed or ground
in the usual way, to from 60 to 80 mesh fineness and may be either wet or dry
crushed.
In wet crushing for this process, none of the water used should be allowed to run
to waste as it would carry some of the fine gold particles with it; the water,
however, may be repeatedly used, but no more water should be used in the crushing
operation than the ore to be crushed or ground will take up and hold within itself
when stacked to a consistency of stiff mortar.
In an earthenware or other suitable article provided with a properly controlled
outlet we place and mix well together.
Hypochlorite of calcium
Muriatic acid
Nitrate of sodium
Water
about 100 parts.
100
"2
23
50
33
22
750
"
The solution thus formed is in about the right proportions for dry materials,
but when it is intended to be used with wet crushed ore, which is preferred, it will
not be necessary to add so large a proportion of water. In determining the
proportion of water, the quantity thereof contained in the wet crushed ore will
have to be estimated and taken into account; no fixed rule will apply as some ores
take up and absorb more water than others.
The wet or dry crushed ore, tailings or other metal bearing body or substance
to be treated is placed in a tank of suitable size, shape and material, and a
quantity of the said solution, sufficient to thoroughly saturate and well cover the
material and to allow for evaporation during the treatment, is added and thoroughly
mixed therewith. Preference is given to a circular iron tank lined with sheet
lead or some suitable composition, or a tank constructed of slate or glazed earthen-
ware or some other suitable material may be used. This tank (called the "mixing
and heating tank") is placed upon a bed of sand and is heated by means of
superheated steam passing through iron pipes contained in the sand, or it may be
otherwise heated.
In some cases it may be convenient to have the mixing tank separate from a
heating tank.
The heat applied may be from about 200 degrees Fahrenheit to near boiling
point, and the time taken to work one batch or charge of ore, tailings or other
substances may vary from about two to three or more hours according to the nature
and fineness of the ore or material. During this time the solution will have
generated sufficient aqua-regia to dissolve all the metals contained in the ore,
tailings or other metal bearing body under treatment.
After the ore, tailings, or other substances under treatment has been subjected

page_text: to the treatment as described for à sufficient time, the contents of the heating tank
are emptied into another tank called the "washing and settling tank" the heating
tank is then ready for re-charging. A quantity of water is then added, the material
When all the
is well mixed, washed and stirred and the whole is left to settle.
earthy matter has settled, the clear liquor which contains all the metals (except
silver) is run or drawn off into another tank or other suitable vessel (called the
precipitating tank") and a saturated solution of sulphide of lime is added and.
well stirred and mixed with the liquor which is then allowed to settle for a sufficient.
length of time to allow of the contained gold being precipitated to the bottom of
the tank. When the precipitation is complete the clear liquor is again run or
drawn off into another precipitating tank or into others, and the other metals
contained in the liquor are precipitated one by one by the addition of suitable
precipitants.
The precipitates are then carefully collected, dried and fluxed and the metal
recovered in the ordinary manner.
In cases where the ores, tailings or other bodies contain silver, the chloride
being insoluble in water is then dissolved in a solution of hyposulphite of soda from
which the silver can be precipitated and recovered in the usual manner.
The washing and settling tanks, as also the precipitating tanks, may be of any
suitable size, shape, and material, with gauges for observing the progress of settling.
and suitable arrangements or appliances for tapping, testing or drawing off liquid
contents, removing the waste earthy matters and collecting the precipitates may be
applied and used.
Dated this 9th day of June 1891.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
An Improved Process of or Means for Extracting or Recovering
Metals from Ores or other Metal Bearing Bodies.
We, WILLIAM NOAD, of 38 Eversleigh Road, Upton Park, in the County of
Essex, Chemist and Assayer, CHARLES MINNS, of 12, Victoria Street, in the City
of Westminster, Civil Engineer, and PHILIP HORDLE STEVENS, of Wool
Exchange Buildings, Coleman Street, in the City of London, Land and 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 :-
This invention relates to an improved process or means of extracting or
recovering gold, silver, copper and other metals which can be reduced to chlorides
by the action of the peculiar solvent hereinafter described, from ores, matrices,
tailings, residues of amalgamation and retorting processes or other metal bearing
bodies, hereinafter intended to be comprehended under the general terms of "ore
or metal bearing body."
The invention consists in the composition of the said solvent and in submitting
the ore or metal bearing body to the action thereof whereby the contained metals
are obtained as soluble and insoluble chlorides which are further treated as
hereinafter described to obtain the respective metals.
The said solvent is prepared by intimately admixing the following ingredients
in about the following proportions, to wit:-Hydrochloric acid; about 100 gallons:-
saturated solution of calcium hypochlorite, about 100 gallons-sodium or potassium
nitrate, (depending upon the class of ore or metal bearing body to be treated)
about 50 lbs. and water, about 750 gallons; and by allowing the admixture to
settle, after which, the clear liquid, (which constitutes the solvent,) is run off into
a second tank containing the ore or metal bearing body to be treated in a finely
crushed condition ;-the respective quantities of the solvent and of the crushed ore

page_text: being such that the latter is thoroughly saturated and well covered by the
former with a sufficient surplusage of the solvent to allow for evaporation during
the treatment.
The second tank is provided with any suitable means for agitating and heating
its contents, which are kept continuously agitated during the treatment, to prevent.
the heavy ore-bodies from settling and caking at the bottom and sides of the tank,.
and are also kept heated (preferably between about 180 degrees, Fahrenheit, and,
boiling point), to facilitate the evolution of chlorine, with which the contained.
metals combine as chlorides.
From 2 to 4 hours of such treatment is usually sufficient, according to the nature
and fineness of the ore under treatment. The contents of the second tank are
then washed out into a third tank, sufficient water being added to liquefy the
mixture, which is again well agitated and allowed to settle to separate the
soluble chlorides of gold and copper or other metal; which will remain i
the solution, from the insoluble chloride of silvertor other metal, which will deposit.
in the settlement.
To obtain the metals of the soluble chlorides, the clear solution is run off from
said third tank successively into a series of tanks wherein the contained metals are
consecutively precipitated by the addition of suitable precipitants.
If, for example, the solution contains the chlorides of gold and of copper, the
gold is precipitated in a fourth tank by the addition to the solution of sulphide of
Time. When such precipitation is complete, the solution is run off into a fifth tank,
and the copper is precipitated by the addition to the solution of metallic iron or
zinc. Should the solution contain other soluble chlorides worth recovering, they
are in like manner consecutively precipitated by the addition of suitable precipitants.
in separate tanks.
To obtain the metal of the insoluble chloride of silver deposited in the settlement.
in the third tank, said settlement is well, washed with sodium hyposulphate, and
the mixture is allowed to settle, after which the clear solution, which will contain
the silver, is run off into a tank and is precipitated as a sulphide by the addition
to the solution of sufficient sodium sulphate.
All said precipitates are carefully collected from their respective tanks, filtered,.
if necessary, dried and fluxed, and the metals separated therefrom by being melted.
down or in any ordinary manner.
The above referred to proportionate quantity of water in the solvent is about
the best if treating dry-crushed ore; but if treating wet-crushed ore, the quantity
of water contained by the latter should be estimated and taken into account in
determining the proportionate quantity of water in the solvent.
The aforesaid tanks may be made of any suitable sizes and shapes and of materials
which will not be acted upon by the solvent or by the various precipitants, and
they may, respectively, be adapted with any suitable agitating and heating
appliances with means for carrying off any injurious fumes generated during the
heating process, and with any suitable appliances for tapping, testing or draining
off the liquid contents, and for discharging the precipitates and waste earthy
matters.
The chemical constituents of the solvent may be compounded in a dry form,
suitable for being packed for transport and export as ordinary cargo, and for use
in the preparation of the solvent at the mines or works, by being dissolved in the
proper quantity of water. We effect this, by concentrating the hydrochloric acid
to about half its bulk-thoroughly drying in an oven or in any other suitable
manner (taking care not to calcine) the requisite proportions of the calcium
hypochlorite and sodium or potassium nitrate; thoroughly mixing the concentrated
acid and said dried ingredients, and admixing therewith, if necessary to absorb any
excess of acid, a sufficient quantity of sodium chloride or other suitable dry and
absorbent material ;-and evaporating the whole to dryness.
By the use of the aforesaid method and means, the cost of treatment of the ore
or metal bearing body is reduced to an almost nominal amount as compared with

page_text: existing methods of treatment, and the advantage is obtained of the whole of the
contained metals treated for, being recovered..
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:-
1. The preparation of a solvent for use in the extraction of gold, silver, copper
and other metals from oves or metal bearing bodies, from the materials hereinbefore
stated when used in about the proportions stated.
;
2. The preparation of the said chemical constituents of said solvent as a dry
compound, suitable for transport, and for use in the preparation of the solvent by
being dissolved in the proper proportion of water.
3. The treatment of ores and metal bearing bodies containing gold, silver,
copper and other metals which can be reduced to chlorides by the action of said
solvent, by such solvent when hot and while continuously agitated so as to extract
such metals as soluble and insoluble chlorides.
4. The method of extracting or recovering gold and copper from ores or metal
nearing bodies by treating the same firstly with such solvent when hot and while
agitated therewith, and by subsequently successively precipitating the soluble
chlorides from the clear solution resulting from said treatment, after the admixture
has been allowed to settle, by the said precipitants.
5. The method of extracting or recovering silver from ores or metal bearing
bodies, by treating the same firstly with such solvent when hot and while agitated
therewith, and by subsequently treating the settlement resulting from said
treatment, after the admixture has been allowed to settle; with sodium
hyposulphate, and precipitating the silver from the resulting clear solution as a
sulphide by the said precipitant.
Dated this 9th day of Auril 1892
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicants.