An Improved Method of Producing Mágnetic Oxide on Wrought or Cast Iron.
Year: 1894

page_text: Date of Application, 7th Dec., 1894
'Complete Specification Left, 9th Sept., 1895-Accepted. 30th Nov.,
1895
"
• PROVISIONAL SPECIFICATION.
An Improved Method of Producing Mágnetic Oxide on Wrought
or Cast Iron.
I PIERRE HENRI BERTRAND, of 12 Rue Violet, à Paris, in 'the' Repúblic" of
France, do hereby declare the nature of this invention to be as follows:
11
If on wrought or cast iron metallic oxides are applied which are not stable such,
for example, as the manganese oxides, these oxides, when submitted to the 'action
of heat, absorb or reject the quantities of oxygen necessary for their variation
until they form a stable oxide. Now, the wrought or cast iron on which these
oxides are applied when oxidising follow exactly the same variations.
Suppose a plate of wrought or cast iron be covered with bioxide of manganese
MnO, and this wrought or cast iron is submitted to the action of heat:
1. At a temperature of 400° to 500° C. the peroxidé of manganese MnO, changes
into sexquioxide Mn,О, and at this moment, the wrought or cast iron "will be
covered with a layer of sexquioxide of iron FeO3-
3
2. If the heat be increased up to 800° to 1000° C. the sexquioxide of manganese
Mo,O, becomes Mn,O,, which is the most stable of the manganese oxides, and at
this temperature the wrought and cast iron would be also oxidised forming Fe3O4,
that is to say, magnetic oxide.
This principle, which forms the basis of my process, not only exists for the
manganese oxides, but also for all the unstable oxides.
I use the least costly of the manganese oxides, and
which are easily oxidised.
The following is my method of procedure:
employ, as vehicles, oils
I boil some peroxide of manganese in oil until I obtain sexquioxide. This
operation gives me an adhesive varnish and suppresses, during baking, the trans-
formation of MnO, into Mu₂O. After having cleaned the object to be oxidised
coat it with 'this varnish thinned in a little oil, I let it dry and raise it'in 'an
oxidising or reducing furnace to a temperature of 800° to 1000° C.
At the end of about twenty minutes the Mn,O, has become Mn30, and magnetic
oxide is formed on the wrought and cast iron. A longer stay in the furnace would
increase the layer of magnetic oxide.
I desire to point out that substances other than the manganese oxides may be
employed, and that vehicles other than oil may be chosen. I 'thus employ with
success a solution of manganese acetate and also obtain good results with cobalt
oxides. It is even possible, by varnishing the mould and its dies with sexquioxide
of manganese Mn2O3, to obtain, by the single operation of casting the iron, a
layer of magnetic oxide, but in this case the subsequent setting of the iron leaves
numerous points of the bare metal and its protection is i incomplete. I have
'therefore described the method which I employ daily and which appears to me to
be the most simple practical and the least costly.
Dated this 7th day of December 1894.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C.; Agents..

page_text: An Improved Method of Producing Magnetic Oxide on Wrought
or Cast Iron.
I PIERRE HENRI BERTRAND, of 12 Rue Violet, à Paris, in the Republic of
France, 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:-
If on wrought or cast iron metallic oxides are applied which are not stable such
for example as the manganese oxides these oxides when submitted to the action of
heat absorb or reject the quantities of oxygen necessary for their variation until
they form a staple oxide. Now the wrought or cast iron on which these oxides are
applied when oxidizing follow exactly the same variations.
Suppose a plate of wrought or cast iron be covered with bioxide of manganese
(MnO2) and this wrought or cast iron is submitted to the action of heat:
1. At a temperature of 400 to 500° C. the peroxide of manganese (MnO2)
changes into sesquioxide (Mn,O,) and at this moment the wrought or cast iron
will be covered with a layer of sesquioxide of iron (Fe,O).
2. If the heat be increased up to 800° to 1000° the sexquioxide of manganese
(Mn,O) becomes Mn,O, which is the most stable of the manganese oxides and at
this temperature the wrought and cast iron would be also oxidized forming Fe̱O
that is to say magnetic oxide.
This principle which forms the basis of my process not only exists for the
manganese oxides but also for all the unstable oxides.
I use the least costly of the manganese oxides and I employ as vehicles oils
which are easily oxidized.
The following is my method of procedure: I boil some peroxide of manganese
in the oil until I obtain sexquioxide. This operation gives me an adhesive varnish
and suppresses during baking the transformation of MnO, into Mn2O3. After
having cleaned the object to be oxidized I coat it with this varnish, thinned in a
little oil, I let it dry and raise it in an oxidizing or reducing furnace to a
temperature of 800° to 1000° C.
At the end of about twenty minutes the Mn,O, has become Mn,O, and magnetic
oxide is formed on the wrought and cast iron. A longer stay in the furnace
would increase the layer of magnetic oxide.
1 desire to point out that substances other than the manganese oxides may be
employed and that vehicles other than oil may be chosen. I thus employ with
success a solution of manganese acetate and also obtain good results with cobalt
oxides. It is even possible by varnishing the mould and its dies with sexquioxide
of manganese (Mn,O,) to obtain by the single operation of casting the iron a
layer of magnetic oxide but in this case-the-subsequent setting of the iron leaves
numerous points of bare metal and its protection is incomplete. I have therefore
shown the method which I employ daily and which appears to me to be the most
simple, practical and the least costly.
In practice I have found the following proportions successful :
In the case where oxide is used one per cent. in oil or one part of oxide to
99 parts of oil.
When salt dissolved in water is used, which salt, when heat is applied, leaves its
acid so as to keep only its base, three per cent. of salt in water is sufficient thus for
magnesium acetate 3 parts of acetate to 97 parts by weight of water.

page_text: 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:
A method for the formation of magnetic oxide on wrought and cast iron by the
application of unstable metallic oxides, substantially as described.
Dated this 9th day of September 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.