IMPROVEMENTS IN THE TREATMENT OF COPPER AND NICKEL ORES
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by George Chetwynd at the Office
of the Commissioners of Patents, with his Petition, on the 10th
January 1866.-A communication from abroad by Viscount Charles
de Secqueville, Mining Engineer, of Milan, in Italy.
I, GEORGE CHETWYND, of Glenmohr Terrace, Blackheath, in the
County of Kent, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE TREATMENT OF COPPER AND NICKEL
ORES," to be as follows, that is to say :-)
The Invention communicated to me consists in an improved process
or improved processes for treating copper and nickel ores for obtaining
these metals therefrom, and the operations by which the same are effected
are as follows:-
First operation. The ground ore or the schlick thereof is to be roasted
in an oven or furnace built of a certain shape, and this ground ore or the
schlick is to be mixed at the time of roasting with about five per cent (or
such other proportion as the variable produce of metal in the ore may
require,) of the residuum of the manufacture of nitric or azotic acid, the
flue of the said furnace or oven being put in communication with a tower
or shaft about 8 yards high, and filled up with coke in such a manner as to
obtain the condensation of acid vapours with the assistance of water.
Second operation.-After the ore or mineral has been roasted in the
manner herein-before described it must be reduced to small pieces by
means of rollers or other crushing apparatus, then roasted again in the

page_text: before-mentioned oven or furnace, and mixed at the same time with a
proportion equal to about fifteen per cent. of a compound mixture of equal
parts of common sea salt, binoxide of manganese, and of the residuum of
the manufacture of nitric acid; it is to be understood that the proportions
of each of the constituents of this mixture may be altered according to the
variable nature of the ore or ores to be treated.
Third operation. The ore or ores or their schlick having thus undergone
the second roasting process as herein-before described may be arranged in
large heaps, and for the term of a week or so these heaps are to be sprinkled
over once each day, or thereabouts, with the acid waters coming from the
tower containing coke as above mentioned for the condensation of the
acid vapours.
Fourth operation. The regular washing of the ore, ores, or schlick,
prepared as before stated, having thus taken place, the concentration of
the saturated waters must be proceeded with after they have been drawn
off by way of decantation, leaving free the gold, which first of all is
precipitated under the action of the dissolved salts of iron, provided however
the ore be auriferous. The copper is afterwards precipitated from its
solution by means of granulated pig iron.
Fifth operation. Reduction of the said copper precipitate in ingots after
fusing it in an appropriate furnace or crucible.
Sixth operation. Concentration of the remaining solutions containing
the salt of iron, and production by crystallisation of green vitriol or sulphate
of iron. The mother waters may be used again to sprinkle over the above-
mentioned heaps of calcined or roasted ore.
Seventh operation.-When the ore, ores, or schlick to be treated contain
at the same time copper and nickel, the preceding operations remain the
same, with the following difference, videlicet, that after having obtained
by previous cementation the copper precipitate, and likewise by crystallisa-
tion the first portion of the sulphate of iron, the mother waters must be
submitted to the following treatment in order to extract the nickel
contained therein, firstly, evaporation of the mother waters in order to
bring the liquor to a density of 30° degrees of Baumés areometer; secondly,
saturation of the said liquor by means of powdered marble or of any sort
of carbonate of lime, the same is afterwards to be set to boil for one hour,
allowed to settle, then again drawn off clear by decantation; thirdly,
dissolution in the above liquor so decanted of hypochlorite of lime of
commerce in the proportion of about 12 grains troy for every quantity of
about 10 quarts of the liquor, with the successive addition of about 14 grains

page_text: of sulphuric acid of commerce, at 50 degrees of Baumé's areometer, or a
proportional quantity of the acid water coming from the condensing tower
may be used; fourthly, the clarified liquor is afterwards to be treated in
the hot with caustic sodaic lime in a suitable proportion, as for instance,
about five ounces 4 drachms for every quantity of about 10 quarts of
the liquid; fifthly, the precipitate resulting from the above treatment is dried
at a heat of about 302 degrees Fahrenheit, then washed cold with hydro-
chloric acid of commerce diluted with water and reduced to 8 degrees of
Baumé's areometer; the portion remaining undissolved is again submitted
to the drying process at a heat of about 248 Fahrenheit, then mixed up
into a paste by means of common nut oil with wheat flour, to which black
flux and dry carbonate of soda have been added, the whole being com-
bined in about the following proportions, videlicet, 100 parts of the said
dry residuum, 20 parts of wheat flour, 75 parts of black flux, and 75 parts
of dry carbonate of soda.
I reserve the right of making use of different reducing agents, such as
oxalic acid, simple hydrogen, or the various known hydrocarburets, and
also the right of combining the above-mentioned parts in different pro-
portions. The powdered residuum mixed up as above is formed into a
sort of cake, which after being dried is cut into small fragments which
are put into a crucible or a set of crucibles, which are to be well covered
with a mixture of black flux and dry carbonate of soda and well luted.
They are then submitted to the heat of burning coke in a proper oven for
about 2 hours, after which spongeous nickel is obtained which is to be
remelted and reduced into regulus by the ordinary means.