IMPROVEMENTS IN TREATING MINERAL WATERS TO OBTAIN. PRODUCTS THEREFROM, AND FOR SEPARATING METALS FROM OTHER MATTERS
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
NAPIER, of Hoxton, in the County of Middlesex, Dyer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twenty-second day of October, in the eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
James Napier, Her especial licence, full power, sole privilege and authority,
that I, the said James Napier, my exors, admors, and assigns, or such others
as I, the said James Napier, my exors, adññors, 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,
my Invention of "IMPROVEMENTS IN TREATING MINERAL WATERS TO OBTAIN.
PRODUCTS THEREFROM, AND FOR SEPARATING METALS FROM OTHER MATTERS ;" in
which said Letters Patent is contained a proviso that I, the said James.
Napier, shall cause a particular description of the nature of my said Invention,
and in what manner the same is to be performed, to be 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 Letters Patent, as in

page_text: 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
James Napier, 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) :-
The first part of my Invention has reference to the treatment of mineral
waters impregnated with copper and iron. I am aware that such waters are at
present treated in order to obtain the copper contained in them, and this is
done by placing therein pieces of iron, by which the copper is thrown down as
a precipitate. The waters, after undergoing this process, are let out, and the
precipitate of copper is obtained mixed with a large quantity of peroxide of
iron. In this process seven parts by weight of iron should substitute and
reduce eight parts by weight of copper, but in practice the destruction of iron
averages ten times the amount of copper obtained. The water, after the
copper has been abstracted, and which contains the iron in solution, is allowed
to run into pits or large reservoirs, where the iron absorbs oxygen from the
air, a small quantity being thus precipitated as an oxide, and then collected
and sold as ochre, after which the water is allowed to pass away. The cause
of the great destruction of iron I have found to result from the existence of
that metal originally in the water in the state of what is known to chemists as a
persulphate, which salt has the property of dissolving almost all metals, so that
by its reaction upon the iron used to precipitate the copper the loss is occa-
sioned; the waters containing this salt being allowed also to pass over the
precipitated copper, a portion of this is redissolved and consequently lost,
besides which the copper which is precipitated upon the surface of the iron
induces a galvanic current, water is decomposed, oxide of iron is formed upon
the surface of that metal, preventing it from operating as intended. The
oxide of iron thus formed falls with the precipitated copper, varying from
seventy to ninety-nine per cent., depending upon the state of the waters.
When amounting to ninety-six per cent. the copper cannot be separated at
á profit.
My improvements consist in, first, the obtaining with certainty a much
larger quantity, amounting to nearly the whole of the copper held in solution,
and in a much purer state than at present; secondly, in a more econòmical
use of the iron employed to precipitate the copper; and, thirdly, in the
recovery, as a valuable product, of the iron originally held in solution, as well
as that used during the process of obtaining the copper.
For attaining the first object, I add a small quantity of sulphuric acid to the

page_text: .waters previously to placing the iron: therein; by this means the oxide of iron
formed by the galvanic action is dissolved, allowing a clean surface of. iron to
be always presented to the copper salt, so that the. -process is facilitated;:the
copper precipitate obtained nearly pure, and the iron; which by tlie ordinary
process: would have been mixed with the precipitate, is dissolved, forining
protosulphate of iron or copperas, to be afterwards obtained by évaporation.
...For the second object; or economising the iron used for the purpose of
precipitating the copper.contained in the waters, I reduce the persulphate of
iron' to the state of the protosulphate before putting in the irons The iron in
solution being thus reduced to the proto state, with the addition of a small
quantity of sulphuric acid the copper may be precipitated with the loss of
little more than an equal weight of iron.
**
For the third object, videlicet, recovering, as a valuable product; tlie iron
contained in the waters, as well as, that used for précipitating thic copper,. I
evaporate the waters treated by the above processes, and crystallize and obtain
from them sulphate of iron or copper; as by which means a large amount of
copperas may be obtained, which could not be done with practical benefit
without the use of free acid. After crystallization the remaining mother
liquor may be treated as at present for the obtaining of ochre. In order
that these improvements in this part of my Specification may be better
understood, I will detail the method I have found to answer well. I provide
a large tank or tanks into which the water to be operated on is collected.
To this I add in the ratio of one pound by weight of ordinary sulphuric acid
or oil of vitrol to fifty gallons of the water. This proportion will vary
according to the state or condition of the water, but the object is to obtain a
small proportion of free acid in the water. I then put into it the requisite
quantity of old: iron. In the course of.a few hours the water will be found
completely exhausted of copper.. At the bottom of the tank before. nien-
tioned I have a tap or plug-hole through which, when the operation is
finished, the water, together with the precipitated copper, is allowed: to pass
into a filtre of sponge, cloth, or other suitable material, in which the copper
is collected, the protosulphate of iron in solution passing through. This is
then run into suitable vessels and évaporated in the usual manner and crys
tallized. If this operation is carried on in the vicinity of smelting works
I find it convenient to use the waste fire of the smelting furnaces to evaporate
the water. For reducing the persulphate of iron to the proto state; I employ
sawdust, which I throw into the reservoir or tanks in which the copper
waters are collected at the same time with the sulphuric acid and the iron, as

page_text: before mentioned. The proportion I have found to answer is half a pound of
sawdust to every fifty gallons of the water. When all the copper is preci-
pitated the water should be allowed to drain out from the reservoirs through
filters, as before mentioned. The unconsumed sawdust may be collected and
used again with fresh mineral waters. I do not confine myself to sawdust, as
other vegetable matters will effect this, and also the soluble portion of the
refuse lime from gas works, but I prefer the use of sawdust, as above men-
tioned. In all mines where such mineral waters as are here mentioned are
found, the ore exists in the state of a sulphuret, accompanied with abundance
of iron pyrites, the roasting of which with suitable apparatus would yield the
sulphuric acid required.
The second part of my Invention has for its object the application to
metallic ores when in a fused state of a current of electricity, so as to separate
therefrom the metals which they contain.
I will proceed to describe the method which I employ in the treatment of
copper ores, though the Invention is applicable to ores of other metals which
are capable of being held in fusion with fluxes. I take a large crucible, or
other convenient vessel, made of an electro-conducting material, those I
have used being of plumbago (common black lead). The inside of this
vessel I line all round with a lute of clay, except the bottom, which I leave
uncovered. The luting should be very thin, and laid on in two or three coats,
drying slowly between each, so as to prevent cracking. When the vessel is
sufficiently luted and dried I put therein (with the usual fluxes) the regulus
or calcined ore, which, when sulphurets are used, should have been well
roasted, so as to drive off as much as possible of the sulphur. I then place
the vessel with its contents in an ordinary air furnace, keeping up the heat
until the mass is in a state of fusion. In the meantime I have prepared an
ordinary voltaic battery of copper and amalgamated zinc, charged with
acidulated water, one part sulphuric acid to twenty-five parts water. To the
positive wire of this battery I attach an iron rod, having rivetted at right
angles to its extremity a flat disc of iron, the disc being a little smaller than
the inner circumference of the crucible. To the negative wire of the battery
I attach a simple rod or bar of iron. The matter in the crucible being in a
state of fusion and well fluxed, I place the above-mentioned disc of iron,
which will now form the positive pole of the battery, on the surface of the
fused mass, and and keep the rod which is connected with the negative pole
in contact with the outside of the crucible, the bottom of which thus forms the
negative pole. The fused matter now forms a portion of the electric circuit,

page_text: and the heat being kept up, the metal is gradually reduced and deposited at
the bottom of the crucible. The proportions which I have found suitable are
as follows:-For every hundredweight of regulus of thirty per cent. of metal,
I employ a battery of five pairs of plates, the size of zinc plates, being three
feet square, and the copper doubled round the zinc in the usual way. The
size of the poles should be smaller than that of the zinc plates; I have found
about. half the size answer well. With apparatus of these proportions the
time for extracting the metal varies from one to two hours. The power of
the voltaic battery, or other means of generating. electricity which may be used,
will vary for different ores, and I have found that if a larger battery be
employed with the same quantity of ore, the time required for the extraction
of the metal will be, shorter, and vice versâ; and if a more powerful voltaic
combination be used, a smaller, sized battery or a shorter time will suffice.
Experience will enable the operator to regulate these matters so as to produce
a good result. I have found that by merely connecting by an external good
electric conductor the iron on the surface of the fused mass and the bottom of
the crucible an electric circuit is formed, and metal is deposited, but the
result is not so satisfactory as when the battery is employed. Whether a
crucible or other vessel or furnace be employed to contain the fused ore, it
should have its bottom, or à sufficient portion of it at the lowest part, formed
in the interior of plumbago or other suitable electro-conducting material with
which the negative rod can come in contact. The positive pole also should
consist of an electro-conducting material, and I have found iron, as above
described, the most convenient and satisfactory, although I have also found
that coke may be used. The thickness of the wires or straps of metal used
for connection should increase with the size of the apparatus. For the
proportions above given I have found straps of ordinary sheet copper of an
inch broad sufficient. The metal so extracted may be refined when necessary
in the usual way.
Having thus described the nature of my Invention, and the manner in
which it is performed, I further state, that I do not confine myself to the
particular details or methods of operating herein mentioned, so that the
peculiar character of my Invention is retained; but what I claim is, in
respect to the first part of my Invention, the addition of sulphuric acid to
mineral waters containing copper and iron previous to reduction; the changing
the solution of iron in such waters from the per to the proto state, and the
obtaining the iron as a protosulphate or copperas.
And in respect to the second part of my Invention, I claim the treatment

page_text: of the ores of copper and of other metals capable of being held in fusion with
fluxes, by applying to these, when in the fused and fluxed state, a current of
electricity. for the purpose of extracting such. metals:...
In witness' whereof, I, the said James Napier, have hereunto set my
hand and seal, this "Twenty-second day of April, in the year of our Lord
One thousand eight hundred and forty-five.
:
JAMES (L.s.) NAPIER.
AND BE IT REMEMBERED, that on the Twenty-second day of April, in
the year of our Lord 1845, the aforesaid James Napier came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified; in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Twenty-second day of April, in the year of our Lord One
thousand eight hundred and forty-five.