IM- PROVEMENTS IN TREATING MINERAL WATERS TO OBTAIN PRODUCTS THEREFROM, AND FOR SEPARATING METALS FROM OTHER MATTERS
Year: 1845

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
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-second day of May, in the eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Napier, my exors, admors, and assigns, 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, adñiors, 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 Her said
Majesty's Islands of Jersey, Guernsey, Alderney, Sark, and Man, and also all
Her said Majesty's Colonies and Plantations abroad, my Invention of "IM-
PROVEMENTS 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

page_text: Chancery within six calendar months next and immediately after the date
of the said in part recited Letters' Patent, 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
James Napier, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are particularly 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 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
occasioned; 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 "a
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
then at procent
1.

page_text: 1. And, thirdly, of the recovery as a valuable product, of the iron originally
held in solution, as well as that used during the process of obtaining tho
copper..
•
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For obtaining the first object, I add a small quantity, of sulphuric acid to
the 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 the
ordinary process would have been mixed with the precipitate is dissolved,
forming protosulphate of iron or copperas, to be afterwards obtained by
evaporation..
For the second object,..or economizing 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 iron, and 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 the iron
contained in the waters, as well as that used for precipitating the copper, I
evaporate the waters treated by the above processes, and crystallize and obtain
from them sulphate of iron or copperas, by which means a large amount of
copperas may be obtained, which could not, be done with practical benefit
without the use of the 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 vitriol
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 mentioned, 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 filter 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 evapor
rated in the usual manner and chrystallized....If this operation is carried on in
the vicinity of smelting works, I find it convenient to use the waste fire of the

page_text: 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 of
tanks in which the copper waters are collected at the same time with sulphuric
acid and the iron, as 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 precipitated, the water should be allowed to drain out from the
reservoir through filters, as before mentioned. The unconsumed sawdust
may be collected and used again with fresh mineral water. 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 saw-
dust, as above mentioned. In all mines where such mineral waters as are
here mentioned are found, the ore exists in the state of a sulphuret, accom-
panied 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 separato
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 crack-
ing. 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,
charged with acidulated water, one part sulphuric acid, 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 in 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 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

page_text: negative pole. The fused matter now forms a portion of the electric circuit,
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 electro
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, and 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 a 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 to the proportion 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 cha-
racter 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 con-
taining coppered iron previous to reduction, for 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
of the ores of copper and of other metals capable of being held in fusion with