Improvements in the Manufacture or Production of Metallic Oxides.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Production of Metallic Oxides.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by the Firm of Schroeder and Stadelmann, of Ober-
lahnstein-on-the-Rhine; in the German Empire), to be as follows:-
1
5
The object of the present invention. is to obtain metallic oxides, particularly
reddish-violet ferric oxide, of great delicacy and intensity, from the corresponding
sulphates.
.
According to this invention the crystals of the sulphate of the particular inetal
whose oxide is to be produced are highly compressed into bricks or blocks which
are then exposed to the action of dry atmospheric air for a time such that they
become so hard as to emit a ringing sound when struck. They are the exposed,
in a blast furnace to a temperature of from 600° and 1300° according to the
shade required: Under this treatment the highly compressed salt, loses tlie pro-
perty of melting in its water of crystallisation, and becoming deliquescent.
The external dimensions of the bricks or blocks are not considerably altered
on further heating, which gradually transforms the material quite uniformly
into highly porous ferric oxide.
In this way there is obtained a shade of unequalled delicacy and richness,
explainable from the following considerations.
When single bricks or blocks weighing about 8 kilograms, are slowly heated,
water of crystallisation is first eliminated. As, however, the bricks or blocks
retain their shape and external dimensions, the same space is occupied, after the
removal of water of crystallisation by dehydrated salt which, in the case of ferrous
sulphate, is 45 per cent. lighter than the original.
In consequence of the expansion brought about by heat, the molecules have
become loosened, and finding the space taken up by water of crystallisation now
unoccupied, they proceed for the most part to fill it.
On increasing the heat, oxides of sulphur are given off, and since there occurs
no shrinkage or change in the external form of the roasted product, "the" pro-
cedure just described repeats itself in the same way, until, when the oxides of
sulphur have been finally removed, the space originally occupied by 8 kilos. of
ferrous sulphate is now taken up by only from 23 to 3 kilos of red ferric oxide,,
according to the shade required.
A remarkable loosening of the molecules has thus taken place, the particles of
coloured oxide being in this way reduced to a state of very fine division.
The roasted product forms a block of porous ferric oxide, having a red to
reddish violet colour, and possessing a great tendency to become disintegrated
when touched..
It is further manipulated by wet methods in the usual way, and when dried,
is powdered in any suitable manner.
.j.
The oxide thus prepared is richer and more delicate than the kinds to be met

page_text: with in commerce; it is just as efficient, and is also from 10 to 15 per cent. more
bulky.
Other metallic oxides, such as those of nickel, copper, and cobalt, can be pre-
pared in the finest condition by this means.
Dated this 9th day of June 1899.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Manufacture or Production of Metallic Oxides.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been com-
municated to me from abroad by the Firm of Schroeder and Stadelmann, of Ober-
lahnstein-on-the-Rhine, in the German Empire) and in what manner the same is
to be performed to be particularly described and ascertained in and by the
following statement:-
The object of the present invention is to obtain-metallic-oxides,-particularly
reddish-violet ferric oxide, of great delicacy and intensity, from the corresponding
sulphates.
According to this invention the crystals of the sulphate of the particular metal
whose oxide is to be produced are highly compressed into bricks or blocks which
are then exposed to the action of dry atmospheric air for a time such that they
become so hard as to emit a ringing sound when struck. They are then exposed
in a blast furnace to a temperature of from 600° to 1300° Centigrade according
to the shade required. Under this treatment the highly compressed salt loses
the property of melting in its water of crystallisation, and becoming deliquescent.
The external dimensions of the bricks, or blocks, are not considerably altered
on further heating, which gradually transforms the material, quite uniformly,
into highly porous ferric oxide.
In this way there is obtained a shade of unequalled delicacy and richness,
explainable from the following considerations.
When single bricks, or blocks, weighing about 8 kilograms, are slowly heated,
water of crystallisation is first eliminated. As, however, the bricks, or blocks,
retain their shape and external dimensions, the same space is occupied, after the
removal of water of crystallisation by dehydrated salt which, in the case of ferrous
sulphate, is 45 per cent. lighter than the original.
In consequence of the expansion brought about by heat, the molecules have
become loosened, and finding the space taken up by water of crystallisation now
unoccupied, they proceed for the most part to fill it.
On increasing the heat, oxides of sulphur are given off, and since there occurs
no shrinkage, or change, in the external form of the roasted product, the pro-
cedure just described repeats itself in the same way, until, when the oxides of
sulphur have been finally removed, the space originally occupied by 8 kilos. of
ferrous sulphate is now taken up by only from 2'3 to 3 kilos of red ferric oxide,
according to the shade required.
A remarkable loosening of the molecules has thus taken place, the particles of
coloured oxide being in this way reduced to a state of very fine division.
The roasted product forms a block of porous ferric oxide, having a red to
reddish violet colour, and possessing a great tendency to become disintegrated
tyhen touched.

page_text: It is further manipulated by wet methods in the usual way, and when dried,
is powdered in any suitable manner.
The oxide thus prepared is richer and more delicate than are the kinds hitherto
met with in commerce; it is just as efficient, and is also from 10 to 15 per cent.
more bulky.
Other metallic oxides, such as those of nickel, copper, and cobalt, for example,
can be prepared in the finest condition by the aforesaid means.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:
In the manufacture of ferric oxide or other metallic oxides, compressing into
bricks, or blocks, the corresponding sulphate under high pressure, allowing these
to harden in dry air, and, when they have become sufficiently hard to emit a
ringing sound when struck, roasting them in a blast furnace at a temperature
between 600° and 1300° Centigrade according to the shade required; substantially
as hereinbefore described.
Tali: CAL
ar
1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.