IMPROVEMENTS IN OBTAINING AND, SEPARATING CERTAIN METALS
Year: 1852

page_text: TO ALL
WHOM THESE PRESENTS SHALL COP 1, ALEXANDER
PARKES, of Pembrey, in the County of Carmarthen, Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the First day of May, One
thousand eight hundred and fifty-two, in the fifteenth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Alexander Parkes, my exors, admors, and assigns, Her especial licence, full
power, sole privilege and authority, that I, the said Alexander Parkes, my.
exors, admors, and assigns, or such others as I, the said Alexander Parkes,
my exors, adiiors, or assigns, should at any time agree with, and no others.
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,,
Wales, and the Town of Berwick-upon-Tweed, in the Islands of Jersey,.
Guernsey, Alderney, Sark, and Man, and in all Her Majesty's Colonies and
Plantations abroad, my Invention of "IMPROVEMENTS IN OBTAINING AND,
SEPARATING CERTAIN METALS;" in which said Letters Patent is contained a
proviso that I, the said Alexander Parkes, should cause a particular
description of the nature of my said Invention, and in what manner the samo.
is to be performed, by an instrument in writing under my hand and seal, to bo
inrolled in Her said Majesty's High Court of Chancery within six calendar.
months next and immediately after the date of the said in part recited

page_text: Letters Fatent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Alexander Parkes, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, that is to say :-
My Invention relates,―
First, to the separation of gold from lead, or alloys of lead, by means
of zinc.
And in order to carry out this part of my Invention, I first fuse the
quartzose, or other combinations containing gold, with suitable fluxing
substances, together with lead or compounds of lead, and whether calcined or
not, as is well understood by metallurgists, the lead or compounds of lead
serving in this operation as a bath to collect the gold. Having obtained the
gold in alloy with lead or its compounds, I proceed to separate the gold from
the lead alloy by means of zinc; and for this purpose I add to every ton of
lead, first raised to a melted state, and containing 10 ozs. of gold to the ton,
1 per cent. of zinc also in a melted state, and in the same proportion for every
additional 10 ozs. of gold, as for example:
10 ozs. of gold I add 22 lbs. 4 oz. of zinc.
To each ton of lead containing 20 oz.
80 oz.
gold
"
44 lbs. 8 oz.
gold
"
66 lbs. 12 oz.
"
دو
Before adding the zinc to the lead alloy, I melt the auriferous lead in an iron
pot, and when at a heat that will melt small pieces of zinc thrown on the
surface as tests of its temperature, I add the required quantity of zinc also
in a melted state, by pouring it into the lead as quickly as possible, and with
perforated skimmers or other means agitate the whole, so as to cause an
intimate combination of the gold with the zinc, which will take place in a few
minutes after the alloy has been well agitated. I allow the whole to remain
at rest for an hour or more, when the zine having taken the gold from the
lead, will rise to the surface of the lead; and when set, or nearly so, I skim it
off, drawing away as much lead as possible; but if the zinc and gold alloy is.
found to have united with much of the lead, I prefer, before separating the
zinc, to put the alloy in an iron vessel, and by the application of heat to sweat
and press out the excess of lead. I then separate the zinc from the gold by
means of acids, or by placing the alloy with a small quantity of carbonaceous
retort, and by the application of heat distil
off the zinc, as is well understood by zinc refiners. I then cupel the auri-
ferous compound in the usual manner, which is well understood.
matter in a clay or other suitable

page_text: I do not confine myself to the proportions herein set forth, as more or less
zinc will be required, according to the amount of impurity in the gold ore or
other compound operated upon. And I have found that this part of my
Invention can be beneficially employed when operating upon compounds
of gold which contain platinum, silver, and other metals, which are
extracted from the lead along with the gold by the agency of the zinc; these
metals, when so obtained, may be separated from the gold by the usual means,
by cupellation, or by the use of acids.
The second part of my Invention consists in obtaining gold and silver from
their ores or other combinations by means of lead, zinc, or other metal or
alloy that will fuse at a lower heat than the compound containing the gold or
silver.
This part of my Invention being similar to the amalgamation process, where
mercury is employed for the extraction of gold and silver, the difference being
that whereas mercury is naturally liquid at ordinary temperatures, and lead
and the other metals I employ are not liquid without heat, I employ such a
degree of heat that will render them liquid and capable of combining with
the silver or gold, but always without increasing such heat to a point which
would fuse the compounds operated upon.
Having ascertained the proportion of gold or silver in the compound to be
operated upon, and placed them in an iron barrel or other convenient vessel,
and heated them to the melting point of the lead, zinc, or other metal or
alloy to be used, I add to every ton of the compound previously reduced into
a state of fine division, and containing from ten to twenty ounces of gold or
silver, from ten to twenty per cent. of lead or other metal or alloy, together
with about five per cent. of chloride of ammonium, or chloride of zinc, or
1 per cent. of carbon may be used either with or without the above-named
salts, and if the silver in the compound to be treated should be in the state of
chloride, I add about 1 per cent. of scrap iron in order to assist in the
reduction of the chloride. I prefer to use an iron barrel or such other
convenient vessel or furnace as will enable me to keep the mixture in motion
for from five to ten hours, by which time I have generally found the gold or
silver to have combined with the lead or other metal thus, employed in fusion
to collect them. I then wash out or otherwise collect the auriferous or
argentiferous compounds, and which I afterwards treat by cupellation or other
means to obtain the gold or silver. In case the compound to be treated for
gold or silver contains sulphur, I then prefer to use zine as the collecting
agent, and I prefer to use lead upon compounds free of sulphur. I do not
confine myself to the above-named salts or carbonaceous matter, or to the

page_text: proportions given, my object being in the use of such salts on carbon to
prevent oxidation of the lead or other metals, and to assist as fluxing or
reducing agents in the combination of the gold or silver with the lead, zinc,
or other metals used for the purpose of collecting them; nor do I confine
myself to the exact proportions of the lead or other metals to be employed,
as the same may be varied, dependent upon the compound to be operated upon,
as may be found necessary in practice.
In witness whereof I, the said Alexander Parkes, have hereunto set my
hand and seal this 1st day of November, in the year of our Lord One
thousand eight hundred and fifty-two.