Improvements in or connected with the Manufacture of Metallic Dust or Bronze Powder.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with the Manufacture of Metallic
Dust or Bronze Powder.
I LEONHARDT OTT, of Roth, in the Kingdom of Bavaria, Director, do hereby
declare the nature of this invention to be as follows:-
The present process has reference to an extremely simple and easy manner of
producing metallic dust or bronze powder.
The molten mass of metal or alloy is placed in a crucible not exposed to the fire,
and whilst it is cooling is stirred with some suitable instrument so as to break
it up in all directions. The relative motion of instrument and mass may be
obtained either by stirring round the implement, or turning round the crucible,
or by moving both simultaneously. The mass thus divided up whilst cooling,
solidifies in the form of small grains of irregular form. By altering the speed,
the degree of fineness of the granulated powder may be changed as desired.
Such granulated powder of metals or metallic alloys can now be used directly
for manufacturing bronze-powder, i.e. a very fine dust of metal or metallic alloy.
This will be effected simply by means of stamping, without any other mechanical
process.
The essential feature of this process consists in the granulated metal directly
before being brought under the stamping press, being cleansed and pickled and
in the stamping process, by which the grains are gradually converted into fine
dust, being from time to time interrupted, so that the metallic powder may be
annealed to render it less hard.
The new process is carried out as follows:-
The cleansing and pickling of the granulated metal may conveniently be done
by means of sulphuric acid and tartar.
The grains are then placed in hermetically closed boxes, where they are ground
by means of a number of stamps operating in succession. As, however, the form
of the grains must be hereby considerably altered, the stamping process is stopped
from time to time, so that the powder may be annealed. This annealing process
occupies but a short time and incurs only little expense, as it is not here a matter
of annealing bars or plates, as has formerly been ordinarily the case in manu-
facturing bronze-powder, but only of a powder, the small particles of which are
much more accessible to the heat.
The bronze-powder thus obtained meets every demand as to lustre, fineness and
softness.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents,

page_text: Improvements in or connected with the Manufacture of Metallic
Dust or Bronze Powder.
I LEONHARDT OTT, of Roth, in the Kingdom of Bavaria, Director, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:—
This invention relates to the manufacture of metallic dust or bronze powder of
sufficient lustre, fineness and softness.
The invention consists in first pickling granulated or like metal or metallic
alloy in a suitable acid bath and then crushing or grinding it under stamps the
stamping or grinding action being stopped periodically so that the powder may
be annealed to reduce its hardness and be pickled to improve its lustre.
In carrying the invention into effect granulated metal or metallic alloy, or the
same in the form of small flat pieces such as may be obtained by casting into a
number of small moulds, is first treated in a suitable pickling bath preferably
dilute sulphuric acid in the proportion of one part of oil of vitriol to 8 to 10 parts
of water and the material is afterwards cleaned by a solution preferably composed
of one part of cream of tartar to 30 parts of water.
in hermetically closed boxes and introduced into an annealing oven. During the
The material is then placed
process of annealing an oxide is formed on the particles of metal and the latter
are again treated with sulphuric acid to remove the said oxide the metal being
also again cleaned with a solution of tartar. The clean material is then ground
by means of a number of stamps operating in succession.
operation considerably alters the state or hardness of the material the stamping
As the stamping
is periodically stopped, so that the powder may be annealed and pickled and
cleaned in solutions such as above mentioned.
process occupies but a short time and incurs only little expense, as it is not a
The annealing and pickling
matter of annealing bars or plates as has formerly been usual in the manufacture
of bronze powder, but only of a powder, the small particles of which are much
more accessible to heat. The bronze powder thus obtained meets every demand as
to lustre, fineness and softness.
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:
-
1. Process of manufacturing bronze-powder from granulated metallic powder
consisting in first pickling or treating such metal with an acid and then bringing
the cleansed and pickled grains directly under stamps, by means of which they
are gradually reduced to metallic dust, the stamping operation being from time
to time interrupted, so that the powder stamped may be annealed to remove its
hardness and pickled to improve its lustre.
2. Process of manufacturing bronze-powder from metal in the form of small
flat pieces consisting in first pickling or treating such metal with a suitable acid
and then crushing it under stamps by means of which it is gradually reduced to
powder the stamping operation being periodically interrupted in order that the
powder stamped may be annealed to reduce its hardness and pickled to improve
its lustre.

page_text: 3.The process for manufacturing bronze-powder substantially
described.
as hereinbefore
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.