IMPROVEMENTS IN SEPA- RATING CERTAIN METALS FROM THEIR ORES AND ALLOYS, AND FOR OBTAINING CERTAIN PRODUCTS THEREFROM
Year: 1853

page_text: LETTERS PATENT to James Napier, of Partick, in the County of
Lanark, Chemist, for the Invention of "IMPROVEMENTS IN SEPA-
RATING CERTAIN METALS FROM THEIR ORES AND ALLOYS, AND FOR
OBTAINING CERTAIN PRODUCTS THEREFROM."
Sealed the 24th June 1853, and dated the 23rd April 1853.
PROVISIONAL SPECIFICATION left by the said James Napier
at the Office of the Commissioners of Patents, with his Petition,
on the 23rd April 1853.
I, JAMES NAPIER, of Partick, in the County of Lanark, Chemist, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SEPARATING CERTAIN METALS FROM THEIR ORES AND ALLOYS, AND FOR
OBTAINING CERTAIN PRODUCTS THEREFROM," to be as follows:-
If the ore is a sulphuret of the metals, I calcine it until the quantity
of sulphur is reduced to one fifth, or thereby, of the weight of the
copper present or contained in it. I then fuse the product along with
carbonaceous matter, viz., coal; and by that means obtain regulus and
"bottoms" of an alloy known as "white metal." If the ore does not

page_text: contain sulphur, I add as much sulphuret ore to it as makes the pro-
portion of sulphur in the whole about a fifth (as before) of the weight
of copper contained in the whole mass of ore. I then fuse the mixture
so formed along with carbonaceous matter, in order to obtain regulus
and white metal, as before. I obtain the copper from the regulus by
any of the ordinary processes of copper smelting; but I treat the white
metal in the following manner :-I reduce it, in the first place, to the
state of powder, by crushing or by any other convenient or suitable
means, and I then oxidize it by exposure to air at a high temperature,
or by chemical agency, as by treating it with nitrate of soda. After it
has been oxidized by any of those means I heat it along with soda or
potash, for the purpose of forming a stannate of soda or of potash. I
then dissolve out this salt by water, and thereby separate it from the
(oxide of) copper, with which the tin is associated in the white metal
powder. To the solution of stannate, thus obtained, I add hydrate of
lime, which, combining with the stannic acid, forms an insoluble stan-
nate of lime and precipitates. In order to procure the tin in the
metallic state, I fuse the stannate of line with any suitable siliceous
and carbonaceous matters; as sand and coal; and to procure the
copper in a metallic state, I mix the oxide obtained by treating the white
metal as above described, with its own weight of regulus, and then
fuse the mixture, whereby the copper is obtained, as in the ordinary
process of roasting; or the oxide may be reduced directly by fusion
with carbonaceous matter.
I separate the tin from its ores by a process similar to that which I
employ for extracting the metal from the white metal alloy, as above
described; namely, by fusing the ore with an alkali, dissolving and
precipitating the tin by lime, and reducing by silica and carbonaceous
matter; and when the tin ore contains copper, it remains insoluble, and
may be obtained from the residue by some one of the known processes
of smelting.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Napier, in the Great Seal Patent Office,
on the 21st October 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JAMES NAPIER, of Partick, in the County of Lanark, Chemist, send
greeting.
2
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of April, in the year
of our Lord One thousand eight hundred and fifty-three; in the six-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Napier, Her special licence,
that I, the said James Napier, ny executors, administrators, and
assigns, or such others as I, the said James Napier, my executors,
administrators, and 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
SEPARATING CERTAIN METALS FROM THEIR ORES AND ALLOYS, AND FOR OBTAIN-
ING CERTAIN PRODUCTS THEREFROM," upon the condition (amongst others)
that I, the said James Napier, I by an instrument in writing under my
hand and seal, should particularly 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 James Napier, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof (that is to say):
My Invention relates to the treatment of the ores and alloys of.
copper and tin.
In treating the ores of copper, I proceed in the following manner :-
I take, first, all those ores that contain sulphur, commonly termed

page_text: sulphurets, and arrange them in two classes, viz, those known or
found by testing to contain tin as an impurity, and those that contain
no tin. In dealing with ores of the first class, I mix them, as far as
practicable, in such proportions that the whole copper in the mixture
shall range from eight to fourteen per cent. of the total weight of the
ores. I then calcine this mixture in the ordinary way, (well known-to
copper smelters,) until the quantity of sulphur remaining in the ore does
not exceed a fifth of the weight of the copper, which may be ascertained
by taking out a small sample, grinding it, and boiling twenty-five grains
in aqua regia for fifteen minutes, diluting the product with distilled
water, filtering, and adding to the filtered liquor chloride of barium, to
precipitate the sulphur. This precipitate being collected, dried, and
weighed, contains three grains of sulphur in every twenty-two grains of
its weight. But in the treatment of ordinary sulphuret ores, a period
of calcination of from sixteen to eighteen hours is found to be sufficient
to expel the excess of sulphur, and I then withdraw the ore from
the calciner and transfer it to an ordinary fusing furnace, adding to
every ton of calcined ore about one hundred weight of coal. This
addition of coal is not essential to the process, but I prefer to use it in
order to obtain clean slag. The whole is then well fused, and the
slagged matter being skimmed off in the usual manner, the "mat or
metallic portion is run off into sand beds. At the bottom of the first
and second beds is found a coarse alloy, known as "white metal,"
and which consists mainly of copper, tin, and iron, with small portions
of such other metals as may have been contained in the ores. This
white metal or alloy I remove, and reserve for another process of
treatment, to be herein-after described; and the remainder of the "mat"
(called "regulus or "coarse metal," now freed from the tin, which
was associated with the copper in the ores, may be roasted and refined
by the ordinary methods; but I prefer to calcine it again for eighteen
hours, and then to fuse it along with other ores containing no sulphur,
such as those commonly imported from Australia, using equal weights of
the ore and of the calcined regulus. A small proportion of coal should
be added to this mixture to obtain clean slag. The product of this
fusion, after a few hours roasting in the usual manner, is fit for refining.
י,

page_text: The second class of sulphuret ores (which contain no tin) I mix in
the same manner as the first class, but in such proportions that the
copper in the entire mass shall not be less than nine per cent. of the total
weight; and this mixture I calcine for twelve hours, and fuse in the
manner above described. Should the copper in the ore have exceeded
twelve per cent. of the total weight, I prefer to add about one hundred
weight of coal to each charge, to prevent loss of copper in the slag.
The coarse metal or regulus obtained by this fusion I calcine again for
twenty-four hours, having previously ground or granulated it in the
usual manner. I then fuse it with ores containing no sulphur, or with
the calcined mat obtained by treating ores of the first class (containing
tin), and the product obtained I. treat by fusing, roasting, and refining,
according to the ordinary methods known and practised by smelters.
When the ores of copper contain tin and no sulphur, I mix them
with sulphuret ores, and, in preference, with such as contain tin, using
such quantity of each kind, as shall give the relative quantity of sulphur
to the copper contained in the mixture, in the proportion herein-before
mentioned, and then I proceed, in the manner above stated, by calcina-
tion and fusion, to obtain the metallic products, viz, regulus and white
metal. When the carthy matters of the mixed ores are difficult to
fuse, a little fluor spar, lime, or oxide of iron may be added as a flux;
but in that case I prefer to let the sulphuret ores be calcined for nine
hours, or thereby, before mixing them with the other ores; the mass
becomes, by this mode of treatment, easily fusible without flux.
The second part of my Invention consists in a method of separating
the tin and copper of the alloy known as white metal, whether pro-
duced by the process, or in the manner herein-before described, or by
any other process whatever. I first grind the alloy to a fine powder.by
any of the ordinary processes, and then I subject the powder to an
oxidising process, preferring the following I subject it for a few hours
to the common operation of calcining at a low red heat. When
oxidised the powder is black, and gives little nitrous fumes when a
little of it is put into dilute nitric acid. But it may be oxidised also by
direct chemical agency, as by heating it along with nitrates or other
compounds which yield oxygen readily by heat..

page_text: .
When the powder has been completely oxidised, I transfer it to an
iron pot containing caustic soda, in the proportion of not less than one
pound of dry caustic alkali to each pound of tin in the alloy. I then
apply heat to the pot (stirring the materials together meantime) until
the temperature is between 600 and 900 degrees of Fahrenheit's ther
mometer, when the soda and oxide of tin combine, and, form stannate
of soda. When the temperature has been inaintained at a low red
heat for about an hour, the mass is transferred from the pot to another
vessel, and allowed to cool, and the pot is again charged with a new
portion of soda and powder:
Caustic potash may be used instead of caustic soda; but in that
case 30 lbs. of the dry alkali must be added for every 100 lbs. of the
powder. Also, carbonate of soda or potash may be used, but I prefer
using the caustic soda. . Also, instead of oxidising the powder in any of
these ways, the oxidation may be effected by adding 30 lbs. of the
nitrate of soda with 20 lbs. of caustic soda to 100 lbs. of the ground
alloy in an iron pot (adding the alloy in small quantities at a time),
and heating the mixture as above described. The metals are thereby
oxidised, and the tin is dissolved. But additional care is necessary
in this process, as the action of the nitrate salt on the metal is sudden
and violent. When the melted mass drawn from the pot is cooled,
water is added, which dissolves the stannate, and the oxides of copper
and iron remain insoluble, and are separated by subsidence, or by
filtration. These oxides are removed and mixed with the charge in
process of roasting, by which the operation is facilitated, and the metal
obtained. To the solution of stannate of soda I add slacked lime,
reduced to a pulpy state by water, using about twenty-seven lbs. of
lime to every one hundred lbs. of the stannate in solution, and boil
the mixture, taking out a little every few minutes, and testing it
with lime water, until no precipitate is produced, when the process
is complete. During this operation an insoluble stannate of lime is
formed, which, when the operation of boiling ceases, subsides to the
bottom, and the caustic soda remaining in solution is used over again
for dissolving the oxide from the powder. The stannate of lime is
collected and dried, and to every six parts are added two parts of silica

page_text: or sand, as free as possible from iron, and one part of anthracite coal or
other carbonaceous matter, and the whole is fused in a reverberatory
furnace, whereby the tin is obtained in the metallic state.
In extracting tin from its ores, I proceed as follows:-The ores, after
being washed and assorted as now done, should the ore be a sulphuret
of tin, I give it a short calcination to convert the tin into an oxide;
when the ore is primarily an oxide of tin, no calcination is required;
and I then proceed with the ore exactly as I have herein-before de-
scribed for the treatment of the calcined or oxidised alloy, using about
seven pounds of soda for every ten per cent. of tin contained in the ore.
All the operations afterwards necessary for obtaining the tin are the
same as I have herein-before described. But should the tin ore contain
a little copper, which is often the case, then the copper will be left with
the other insoluble matters in the ore when the stannate of soda is
dissolved out, and may either be reduced by fusing with carbonaceous
matters, or it may be collected, dried, and sold as copper ore.
Having thus described my Invention as applicable particularly to
ores of copper and tin, and the alloys of those metals, I wish it to be
understood that my improvements are likewise applicable to all matters
containing those metals, or their oxides, and that I claim the applica-
tion thereto accordingly.
In witness whereof, I, the said James Napier, have hereunto set
my hand and seal, this Nineteenth day of October, in the year of
our Lord One thousand eight hundred and fifty-three.
JAMES NAPIER. (L.S.)
Witness, W. M. BUCHANAN,
37, Paterson St., Kingston, Glasgow.