IMPROVEMENTS IN TREATING AURIFEROUS AND ARGENTIFEROUS ORES AND SUBSTANCES
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at
the Office of the Commissioners of Patents, with his Petition, on the
31st August 1859.-Communicated to me from abroad by Dr. Raoul
Destrem, residing in Paris.
J, RICHARD ARCHIBALD BROONAN, of 166, Fleet Street, in the City of
London, E.C, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN TREATING AURIFEROUS AND ARGENTIFEROUS
ORES AND SUBSTANCES," (communicated to me from abroad by Dr. Raoul
Destrem, residing in Paris,) to be as follows:-
This Invention relates to crushing, washing, and concentrating gold and
silver ores by means of known apparatuses, by rendering available the rever-
beratory and other furnaces used for melting lead ores in order to treat at the
same time gold and silver ores, or auriferous or argentiferous substances mixed
with finely divided iron, either pure or oxydised. I introduce into the furnaces
a mixture of from 50 to 75 per cent. of lead ore, or if compounds containing
lead, such as sulphurets, carbonates, sulphates, or oxides of lead resulting from
the calcination of other lead ores or of residuums containing lead left from
preparations of lead with 25 to 50 per cent. of gold or silver ores or of auriferous
and argentiferous substances, such as, 1st, auriferous or argentiferous earths
of an argillaceous, ferruginous, or other character combined with the various
metallic veins, such as lithomarges) which are considered to result from the
waters of the earth charged with carbonic, silicic, or other acid conveying lead,
copper, and other metals united with gold and silver with them, decomposing

page_text: jasper and other matters under the influence of electric currents, and leaving
salts of gold and silver as less soluble and less attackable; 2nd, veins of
auriferous and argentiferous matters more or less rich alone or combined with
other metallic matters in the same veins, such as pyrites of iron, of arsenic, or
of copper, and others. In such case a previous roasting is necessary, and the
resultant products from such roasting only are treated in the furnaces, and these
products generally consist of oxides of iron, or of copper mixed with as much
gold or as much silver as may be found there; 3rd, the residuum left from
the treatment of these precious metals with mercury; 4th, auriferous precipi-
tates obtained by aqua regalis, and by precipitation by means of proto-salts of
iron upon certain auriferous matters, such as auriferous tin ores, and others.
I obtain these auriferous precipitates by treating the auriferous matters (united
with bodies little susceptible of action from aqua regalis) with a fifth of aqua
regalis freshly prepared; I place the mixture in earthen vessels, and leave
them from 5 to 6 hours on a sand bath arranged upon the top of the
furnaces, in order that the mixture may macerate under what would otherwise
be waste heat. Chlorine in its nascent state attacks the gold; the chloride is
dissolved by copiously washing the matters treated in water, and the gold is
precipitated by a solution of proto-sulphate of iron; gold in powder falls on
the bottom of wooden vessels in which the solution with the washing waters
is received, about 3rds of the water is decanted, and the remaining third is
filtered through woollen filters which retain all the gold; I then burn these
filters, and cast the results of the burning into the furnaces; the gold mixes
with the lead therein, and runs with it; 5th, the residuums in the state of
sulphuret and chloride of silver, which are retained, or which remain in sands,
and auriferous and argentiferous matters treated with chlorine gas, sulphuric
acid, and by roasting and washing; 6tb, generally all residuums resulting
from the daguerreotype process, from gilding and silvering processes, and from
all others in which auriferous or argentiferous substances have been used. I
also introduce into the furnaces, and at the same time as the mixture of the
ores and metalliferous substances, reducing agents suitable both in quality and
quantity to the substances under treatment.
According to this industrial treatment, says the Inventor, the reducing
operations are effected under the influence of heat and of currents of air and
of steam successively or simultaneously applied, or under the influence of the
chemical action of 16th of finely divided iron or of spongy iron.
In my processes the bodies react, as it were, in their nascent state, or in
their passage to the fluid state, in quitting one combination to form another in
contact with and under the influence of chlorine of lead, of iron, under the

page_text: influence of heat or rather of electricity naturally developed at that moment.
Lead, in separating from any combination to run, carries with it any gold and
silver that may be present by combining with them at the moment of their
abandoning their primitive or natural combination to unite with the lead.
The precious metals are subsequently separated from the lead by any of the
well-known means ordinary followed to effect such separation.