IMPROVEMENTS IN OBTAINING COPPER FROM CUPREOUS PYRITES.
Year: 1870

page_text: LETTERS PATENT to Jonathan Down, of Widnes, in the County of
Lancaster, Metallurgist; for the Invention of "IMPROVEMENTS IN
OBTAINING COPPER FROM CUPREOUS PYRITES.".
}
Sealed the 11th April 1871, and dated the 24th October 1870.
PROVISIONAL SPECIFICATION left by the said Jonathan Down at the
Office of the Commissioners of Patents, with his Petition, on the
24th October 1870..
I, JONATHAN DOWN, of Widnes, in the County of Lancaster, Metal-
lurgist, do hereby declare the nature of my said Invention for "IMPROVE-
MENTS IN OBTAINING COPPER FROM CUPREOUS PYRITES;" to be as follows:-
This Invention relates to the treatment of solutions containing copper
obtained from the roasting or calcination of cupreous pyrites, or from the
roasting or calcination of the burnt or calcined cupreous pyrites with salt,
and then extracting the copper rendered soluble either by means of water
or by means of water and acid, and consists in submitting such solutions to
the action of a base, such for example, as lime or carbonate of lime, so as
to neutralize any free acid which may be contained therein. so that when

page_text: the copper contained therein is precipitated by means of iron the copper
is obtained in a purer condition. A smaller quantity of iron is employed
and impurities such as arsenic or antimony, should they be present, are
retained in solution.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Jonathan Down in the Great Seal Patent Office on
the 22nd April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JONATHAN
Down, of Widnes, in the County of Lancaster, Metallurgist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of October, in the
year of our Lord One thousand eight hundred and seventy, in the
thirty-fourth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Jonathan Down, Her special
license that I, the said Jonathan Down, my executors, administrators,
and assigns, or such others as I, the said Jonathan Down, my exe-
cutors, administrators, or assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
OBTAINING COPPER FROM CUPREOUS PYRITES," upon the condition (amongst
others) that I, the said Jonathan Down, my executors or administrators,
by an instrument in writing under my hand and seal, should par-
ticularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Jonathan Down, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, that is to say :—
These improvements relate to the treatment of solutions containing
copper obtained either from the roasted or from the calcined cupreous

page_text: .
pyrites, or from the roasted or calcined burnt ore (or calcined cupreous
pyrites) with salt or of solutions containing copper produced by acids or
other methods as well as solutions containing copper obtained from mines
or other places. These solutions whether produced artificially by the
decomposition of copper pyrites, burnt ore, or obtained from other
substances containing copper in any other form, either by the use of salt,
acids, or otherwise, as well as solutions from copper mines or from any
other deposits containing copper by natural decomposition or otherwise
always or almost always contain more or less free acid, frequently to a
very large extent, as well as arsenic, antimony, and other metals foreign
to and very injurious to the copper if precipitated with that metal. By
submitting such copper solutions to the direct action of metallic iron for
the purpose of precipitating the copper, and especially when excess of
free acid is present, most of the arsenic and antimony present is also
precipitated, and a very much larger quantity of iron is consumed than
is necessary when the solutions are neutral or nearly neutral, and the
quality of the copper so produced is inferior in proportion to the amount
of free acid, antimony, arsenic, and other impurities contained in the
solution.
In order to obviate such objections I neutralize so much of the excess
of acid contained in the solution as that the free acid left retains the
arsenic and antimony in solution, and yet is sufficient to prevent the
precipitation of the copper being too slow.
I effect this necessary degree of neutralization by bringing the solutions
in contact with a base such as lime or carbonate of lime in a vat or pit
in which the contents can be occasionally stirred, and allow them to
remain in contact for a shorter or longer period, but by preference
allowing them to remain in contact until the salts of iron present in the
solution with the copper begin to precipitate. As soon as this takes
place the solutions are sufficiently neutral to be removed and run
into the precipitating vats containing iron, but if preferred the neutra-
lization may be effected wholly or in part in the precipitating vats.
The effects resulting from neutralizing the copper solutions are that
the quantity of iron necessary for precipitating the copper is reduced in
proportion to the amount of free acid neutralized, but the solution so
neutralized must contain acid enough to keep the greater part of the
arsenic, antimony, and other foreign metals which may be present from
precipitating with the copper, as it will be found that these foreign

page_text: metals are precipitated with the copper only when the solutions are too
acid, but on the other band the solutions must not be neutralized to such
an extent as that any material amount of the salts of iron are pre-
cipitated by the base used, as in that case the precipitation of the copper
will be slow, and salts of iron, arsenic, and other impurities will fall
with it.
Having now described and particularly ascertained the nature of
my said Invention and the manner in which the same is or may be
used or carried into effect, I would observe in conclusion that what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,
the neutralizing of solutions of copper such as herein described by any
base to such an extent as to retain the greater part of the arsenic, anti-
mony, and other impurities in solution when the copper is precipitated
from such solutions by metallic iron.
In witness whereof, I, the said Jonathan Down, have to this my
Specification set my hand and seal, this Nineteenth day of April,
One thousand eight hundred and seventy-one.