IMPROVEMENTS IN DYEING, CERTAIN PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE MANUFACTURE OF METALLIC ALLOYS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
OXLAND, of Plymouth, Chemist, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Second day of
September, One thousand eight hundred and forty-seven, in the eleventh
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Robert Oxland, my exors, adiñors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said
Robert Oxland, my exors, admors, and assigns, or such others as I, the said
Robert Oxland, 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 England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "IMPROVEMENTS IN DYEING, CERTAIN PARTS OF WHICH IMPROVEMENTS ARE
APPLICABLE TO THE MANUFACTURE OF METALLIC ALLOYS;" in which said Letters
Patent is contained a proviso, that I, the said Robert Oxland, should cause
a particular description of the nature of my said Invention, and in what
manner the same is to be performed, by an instrument in writing under my
hand and seal, to be inrolled in Her 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 and by the same, reference being thereunto
had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Robert Oxland, 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, reference being had to
the Drawing hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
These improvements consist in preparing and applying the tungstate of soda
as a substitute for the various preparations of tin usually employed as mordants
in dyeing. This substance may be used either alone or in combination with
various acids, according to the purposes for which it is required. When it is
required to be employed in combination with acids, it is necessary that it
should first be dissolved in a much larger quantity of water than is merely
necessary for its solution, say, one ounce of the salt in a quart of water, the
acid may then be added until all the alkali is saturated and a small quantity
of acid is found in excess. Wool, either in skein or piece, may be dyed by
either first boiling in such a solution as that just described, in which nitro-
muriatic acid has been employed, and subsequently in the dye bath, or it may
at once be mixed with the dye, and the cloth boiled with the mixture without
any other previous preparation than the usual cleaning with logwood as the
dye; by such treatment as the foregoing, a violet color is produced, passing
into a claret, and finally, if the boiling be continued, into a black. For the
manufacture of tungstate of soda, I employ wolfram, the native tungstate of
iron, and manganese. I have been informed that native tungstic acid is
occasionally met with in considerable quantities; should this substance be
obtainable, it may be employed as a substitute for wolfram, with the same
process and apparatus. The wolfram is found either alone, or more frequently
associated with tin ores. When the tin ores are employed they are to be
dressed in the usual manner until ready for smelting. The proportion of
wolfram present in the ores having been ascertained by analysis as is well
understood, and the ore having been dried, I mix with it common alkali or
soda ash, having first ascertained by analysis the quantity of alkalimetrical
soda present in it in the proportion of the chemical equivalent of the tungstic
acid contained in the wolfram mixed with the ore, i. e. suppose the ore to
contain twenty per cent. of wolfram, every one hundred parts of such ore will
contain fifteen parts tungstic acid, the chemical equivalent of soda for which
will be three and a half parts. If a soda ash of fifty per cent. has been
employed, then the quantity of soda ash required will be seven parts. The ore
and alkali having been thoroughly mixed, the charge may be put into the
furnace.
I employ the sulphate of soda or salt cake instead of alkali.

page_text: I may
here observe that I describe both processes, because while that with
alkali is more expensive, it has the advantage of being more manageable by
inexpert workmen than the process with sulphate of soda. The salt cake in
fine powder is to be used in the proportion of eight parts for seven of alkali of
fifty per cent., mixed with one-fourth its weight of coal in fine powder, and is
to be combined with the ore in the same manner as when alkali is used; but
when the charge is in the furnace it requires to be exposed to the action of
heat longer than when alkali is employed, or until all appearance of combus-
tion has entirely ceased.
The charge drawn from the furnace will consist of the native oxide of tin,
the soluble tungstate of soda, with the oxides of iron and manganese, with a
small proportion of silica.
In order to separate these substances from each other, the following process
of lixiviation is to be adopted :-Three vats of wood or iron of suitable dimen-
sions, say, five feet long, three feet wide, and three feet deep, or of any other
form of similar capacity, may be arranged side by side, and below cach a
vessel of about one-third the capacity of the vat, to receive the liquid running
down from the vat. In the bottom of the side of the vat, immediately over
the receiver, should be a plug hole.
On the interior of the vat, in front of this hole, should be placed a filter,
consisting of a little straw or tow, over which a piece of metal pierced with
holes is placed, and kept down by a few clean stones. The first vat being par-
tially filled with water, the charges, when cooled down to a black heat, is
thrown into it until it is very nearly full. The vat is then filled up with water,
and after standing about half an hour, the plug is partially drawn, and the
clear soloution of tungstate of soda is allowed to run down into the receiver,
whence it is removed into the evaporating pans. For testing the strength of the
solutions, and to determine thereby when the whole of the soluble matters
have been removed from the ore, I employ Twaddell's hydrometer. As the
liquor runs down, the vat should be kept filled up with water, but when the
liquor in the receiver is reduced to the strength of twenty-five of the bydro-
meter, it should be no longer removed to the evaporating pan, but pumped up
into the second vat for commencing the lixiviation of the next lot of calcined
products from the furnace, instead of employing water alone. The weaker
solutions from No. 2 are passed on to the fresh charge in No. 3 vat, No. 2
being continually filled up with liquor running down from No. 1, until the
hydrometer no longer indicates the presence of any saline matter in it, or at
most not more than two or three degrees. The strong solution obtained as
just described should be concentrated in iron evaporating pans until brought

page_text: up to the crystallizing point, indicated by the formation of a permanent saline
crust over the surface of the liquor, which is then to be removed to suitable
coolers, and to be allowed to remain until the crystallization is completed.
The crystals should be removed, and the mother liquor mixd with other
liquor in the evaporating pans, in order to be again crystallized.
The annexed Plans will serve to shew the form of the furnace which I
have employed with most advantage, Figure 1 being a plan, Figure 2 a longi-
tudinal section, and Figure 3 a transverse section. The sole of the furnace (a)
consists of a cast-iron plate, cast in two pieces, the joint being formed across
the breadth of the furnace. The length is nine feet, the breadth in the
widest part six feet, and one inch thick throughout. The fire passes over, the
plate returns below, and circulates beneath it, as shewn in the plan, before it
passes away to the main flue or chimney. The furnace is charged through the
hole 6 in the top, and the charge is drawn through the hole c in the sole a,
from which, through the flue beneath into the arch below, a communication
is opened, which may be covered, when the charge is not being drawn, by a
small plate of iron, which is always kept in the furnace. According as the ore
may be coarse or fine grained, the charges will vary from six to ten hundred-
weight of ore, with its complement of alkali. The coarse grained ore may be
put into the furnace in the largest quantity.
If the furnace be kept at a good red heat, and the charge be well managed;
eight charges per diem of twenty-four hours may be drawn. The charge is to
be turned over from time to time as it lies in the furnace, in order to get it
equally hot throughout; but as the front part of the charge, or that nearest to
the fire, will be ready first, a portion of the charge may be first drawn, another
portion of it turned forward to the fire, and so successive portions drawn until
the whole of the charge be removed. If the charge has been thoroughly
worked in the furnace, it will be found that as soon as the red heat has
disappeared it will have caked into a hard mass, which should be broken into
lumps before it gets too cold.
The other part of my Invention, which has reference to improvements in
the manufacture of metallic alloys, consists in preparing metallic tungsten for
the manufacture of its various alloys with other metals. I obtain this metal
from the tungstate of soda by the following processes :-
First, I prepare tungstic acid by digesting the tungstate of soda in cold
muriatic acid, removing the solution obtained, and adding successive portions
of the acid until all the tungstate of soda is decomposed. The tungstic acid
should be further washed with cold water, to remove any adhering saline
matters, and then dried on brick or earthenware. The tungstic acid thus

page_text: obtained may be reduced to the metallic form by mixing it with a coarse oil
or tar, or with charcoal, or coal in fine powder, putting the mixture in a
crucible lined with charcoal, and exposing the mixture for about one hour to a
strong red heat.
Second, I obtain the metallic tungsten from the tungstate of soda by mixing
it with charcoal dust or powdered coal, and exposing the mixture in charcoal-
lined crucibles to a strong red heat for about an hour. The tungstic acid will
be reduced to the metallic form, and the soda originally in combination with
the tungstic acid will have been converted into the carbonate of soda, which
may be separated by lixiviation, leaving the metallic tungsten clean and ready
The solution of carbonate of soda may be evaporated to dryness, and
again employed as alkali in this manufacture.
In witness whereof, I, the said Robert Oxland, have hereunto set my
hand and seal, this Second day of March, in the year of our Lord One
thousand eight hundred and forty-eight