A New Method of Preparing Iron for Alloying with other Metals generally, and particularly with Copper and Zinc.
Year: 1891

page_text: Date of Application, 15th Aug., 1891
Complete Specification Left, 15th June, 1892-Accepted, 15th Nov., 1892
PROVISIONAL SPECIFICATION.
A New Method of Preparing Iron for Alloying with other Metals
generally, and particularly with Copper and Zinc.
I, HENRI PIDOT of Boulevard Montmartre, Paris, in the Republic of France,
and of 49 Stanhope Gardens, London S.W., Engineer, do hereby declare the nature
of this invention to be as follows:-
This invention relates to the preparation of iron for alloying with other metals
generally, and particularly with copper and zinc for the production of a white alloy
termed iron-silver."
Cast iron in the form of turnings, filings, or powder, is immersed in a bath of
hydrochloric acid through which is passed a current of carbonic acid gas. The
effect of the said carbonic acid gas is to prevent the formation of protochlorides and
perchlorides of iron. Currents of air and steam are then passed through the bath
and the liquid drained off from the residue which is afterwards dried and alloyed
with the other metals.
For the production of the shore mentioned itimam a:1…………”
COMPLETE SPECIFICATION.
A New Method of Preparing Iron for Alloying with other Metals
generally, and particularly with Copper and Zinc.
I, HENRI PIDOT, of 49 Stanhope Gardens, in the County of Middlesex, Engineer,
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 a method of treating iron whereby it may be alloyed in
all proportions with copper, with, or without, the addition of other metals, thus
forming a complete series of bronzes from the red-yellow to the silver-white colour,
called Pidot's "Iron-silver" and "Ferro-bronze."
According to my invention it is possible to alloy iron and copper in all proportions
either alone or with the addition of other metals such as zinc, tin, nickel, aluminium,
lead, manganese, etc., so as to form a series of new alloys having a base of iron and
copper and of great commercial value being applicable to almost, if not all, purposes
to which iron, copper, and bronze, have been applied. In some cases copper may
be entirely omitted from the alloy as is hereinafter more fully described.
These alloys may be cast, rolled, drawn, tempered, forged, soldered, punched and
otherwise cut and worked.
Notwithstanding all these advantages combined in this series of alloys, their
cost of production is very low as the materials employed in their composition are
for the most part scrap metal.
Cast iron in the form of turnings, filings, or other convenient form, is immersed
in a bath of hydrochloric acid through which is passed a current of carbonic acid
gas. The effect of the said carbonic acid gas is to prevent the formation of definite

page_text: manner.
Though the above mentioned process gives very good results I find it to be
advantageous to modify it in the following manner:
Cast iron in the form described above is immersed in a bath of hydrochloric acid
which may be diluted with water, or not. When the surface of the metal has under
the action of the acid, become clean and brightened I pass a current of steam for
about half an hour through the liquid, and after this, a current of carbonic acid gas
for about the same length of time. Carbonic acid gas is passed through the bath
for about the same time once a day but the current of steam is not repeated. The
object of this operation is to prevent the formation of definite protochlorides and
perchlorides of iron though an indefinite form of these salts is formed. When it
has stood about three days, I introduce into the same bath, which may be revived
by the addition of more acid and used over and over again, variable proportions of
copper, or copper and zinc, which soon become amalgamated with the iron.
After standing for five days or longer, the metals become reduced to a pulverulent
mass from which the liquid is decanted.
To hasten the formation of the said pulverulent mass, saw-dust may be added to
it when in the bath so as to form a pasty mass. This is then roasted on a stove or
hearth where it becomes completely carburetted. This carburetted mixture is then
smelted in a suitable crucible, cupola, or other furnace when the required pro-
portions of other metals or alloys, such as copper, brass, zinc, aluminium, lead, tin,
nickel, manganese, etc. may be added.
It will be seen that in this modified process a portion of the copper and zinc
(which may be in the form of brass) is added to the iron when the same is in the
bath already described, instead of first introducing the metals to one another in the
crucible. In cases where it is desired that the alloy should contain no copper but
consist merely of iron and one or more of the other metals, the first mentioned
process would be observed, and such other metal or metals would be first introduced
to the iron in the crucible.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
-
(1) The method of preparing iron for alloying with other metals by treating the
same to the action of a bath of hydrochloric acid through which currents of steam
and carbonic acid gas are passed, substantially as and for the purpose hereinbefore
set forth and described.
(2) The addition of copper alone or copper and zinc either separately, or alloyed
as in the form of brass, to iron while it remains in the bath mentioned in the last
preceding claim, as and for the purpose hereinbefore set forth and described.
(3) The series of alloys obtained by the process hereinbefore set forth and
described.
Dad thin with dan of T1000
CASTLE SMITH,
"Invention " Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.