AN IMPROVEMENT IN THE MANUFACTURE OF TUNGSTIC ACID AND ITS COMPOUNDS
Year: 1884

page_text: I, ALFRED KIRBY HUNTINGTON of King's College Strand, in the County of
Middlesex, Professor of Metallurgy do hereby declare the nature of my Invention
for "AN IMPROVEMENT IN THE MANUFACTURE OF TUNGSTIC ACID AND ITS
COMPOUNDS," to be as follows:-
The principal ores of tungsten, such as Wolfram and Scheelite, contain tungstates.
The object of my Invention is to separate, by a cheap and simple process, the
tungsten from its ores as a tungstate of an alkali metal, such as tungstate of soda
or potash, and to treat this tungstate for production of tungstic acid.
For this purpose, I mix with the ore, which may be previously calcined, an
alkaline oxide, or suitable alkaline compound, and such fluxes as may be found by
experiment to be necessary, and I subject the mixture to heat in a furnace. The
fused tungstate of the alkali metal being of great specific gravity, sinks to the
bottom, and may be tapped off, or, after partial cooling, the slag may be removed,
leaving the tungstate. Should the tungstate contain impurities, it may be refined
by fusing it again with addition of some substance, such as silicate of soda or
glass, that will take up the impurities and form a slag which can be separated, as
above described, from the tungstate. The tungstate thus obtained is available for
use, or it may be dissolved in water and crystallised, or treated for the production
of oxide of tungsten and metallic tungsten. For producing oxide of tungsten, the
tungstate solution may be treated with substances such as lime or magnesia, or
salts of these, which throw down insoluble tungstates; and these may then be
treated by an acid, such as hydrochloric acid for lime, or sulphuric acid for
magnesia, forming a soluble solution of the lime or magnesia, and precipitating the
tungstic acid.
The tungstate, instead of being treated as above described, may
have added to it concentrated sulphuric acid, whereby insoluble tungstic acid will be
thrown down.
Data 41: 1nt
1004
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.

page_text: "
I, ALFRED KIRBY HUNTINGTON of Kings College, Strand in the County of
Middlesex, Professor of Metallurgy, do hereby declare the nature of my said
Invention for AN IMPROVEMENT IN THE MANUFACTURE OF TUNGSTIC ACID
AND ITS COMPOUNDS" and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
The principal ores of tungsten, such as Wolfram and Scheelite, contain tungstates.
The object of my Invention is to separate by a cheap and simple process, the
tungsten from its ores as a tungstate of an alkali metal such as tungstate of soda
or potash, and to treat this tungstate for production of tungstic acid.
For this purpose, I mix with the ore, which may be previously calcined, an
alkaline oxide, such as soda or potash, or suitable alkaline compound, such as
carbonate of soda or soda ash, and such fluxes as may be found by experiment to
be necessary, and I subject the mixture to heat in a furnace. In some cases,
addition of a flux may be unnecessary, but where there is a deficiency, for example,
of silicious matter in the ore, that may be added in the form of sand or crushed
quartz. The fused tungstate of the alkali metal may be tapped off, or, after partial
cooling, the slag which separates in setting may be removed leaving the tungstate.
Should the tungstate contain impurities, it may be refined by fusing it again with
addition of some substance such as silicate of soda or glass that will take up the
impurities and form a slag that can be separated as above described from the
tungstate.
The tungstate thus obtained is available for use or it may be dissolved in water
and crystallised or treated for the production of oxide of tungsten and metallic
tungsten.
For producing oxide of tungsten, the tungstate solution may be treated with
substances such as lime or magnesia, or salts of these, which throw down insoluble
tungstates; and these may then be treated by an acid, such as hydrochloric acid
for lime, or sulphuric acid for magnesia, forming a soluble solution with the lime or
magnesia, and precipitating the tungstic acid. The tungstate, instead of being
treated as above described may have added to it concentrated sulphuric acid,
whereby insoluble tungstic acid will be thrown down.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
The manufacture of tungstic acid and its compounds by melting to a liquid
condition tungsten ore in admixture with alkali, separating the tungstate from the
slag, and afterwards treating it, if required, for production of tungstic acid or
tungstates, substantially as described.
Dated this 26th day of September 1884.