Improvements in Processes of Dephosphorizing Steel and other Metals.
Year: 1898

page_text: Improvements in Processes of Dephosphorizing Steel and other
Metals.
I, JOHN GORDON, c/o Edward Johnston, Son & Co, of Rua Sao Pedro, Rio de
Janeiro, Brazil, South America, Inventor, do hereby declare the nature of this
invention to be as follows
-
My invention relates chiefly to the manufacture of iron and steel and has
for object the removal of phosphorus therefrom but the process may be used
also for dephosphorizing other metals, for instance copper
I have observed that, in rock-forming magmas, slags, etc., the phosphorus
present seeks, by preference over other substances, the rarer earths and their
metals, forming monazite, xenotime, and other similar phosphates I have also
found in the manufacture of steel by the basic or lime process that,
while most of the phosphorus present combines with the lime, some still
remains in the molten metal and that it is possible to remove a further
amount, if not all, by using the rafer earths or their metals, or the carbides,
fluorides, cyanides, silicates, or other salts of such metals, or mixtures of these
compounds. These metals, oxides, and carbides, possess a stronger affinity for
phosphorus than lime or magnesia
My invention therefore consists in causing to re-act with the molten metal
containing phosphorus either the rarer earths, or their metals, or the carbides
or other compounds thereof, or two or more of these substances, all as hereinafter
described.
86
"
It is well known that by the term rarer eartha are designated the oxid.s
of cerium, lanthanum, didymium, erbium, terbium, thorium, yttrium, holmium
samarium, and others, in fact the usual bases of the minerals monazite, xeno-
time, and allied phosphates. These metals are also termed the metals of the
cerium group.
In dephosphorizing iron or steel I cause to re-act with the molten metal the
oxides of the rarer elements above defined, or these elements themselves in a

page_text: metallic state, or as carbides This treatment is applicable and effective with
the open hearth process as well as with the Bessemer or basic process
I may
also employ as dephosphorizing agents, alloys or compounds of the metals of
the cerium group or of their carbides, with iron or with iron and manganese
(ferro-manganese) forming new metals or alloys. I find that by applying these
elements as oxides, or in the metallic state, or as carbides, etc., especially when
previously alloyed with non or ferro-manganese, I effect a more intimate union
with the phosphorus contained in the iron or steel and facilitate the combina-
tion, the result being the slagging off of the phosphorus as phosphides or
phosphates.
It will be understood that the quantity of the dephosphorizing agent will
depend on the amount of phosphorus contained in the metal to be dephosphorized
and on the nature (chemical equivalent) of the said agent The percentage of
phosphorus 18 determined by an analysis, say, of the pig iron and the quantity
of oxide required is a mere matter of calculation in the manner well known
to metallurgical chemists Thus for cerium oxide the quantities, calculating
by the chemical equivalents, will be in the proportion;—
so that, roughly speaking, the quantity of the oxide would be about five to six
times the percentage of phosphorus determined by analysis in the pig iron of
the charge
As hereinbefore stated the process is applicable to the dephosphorizing of any
metal, the operation being substantially the same in all cases, namely, con-
sisting in the production of a reaction between the above defined dephosphorizing
agenta and the molten metal.
It will be understood that I employ as dephosphorizing agents all the metals
of the raier earths or of the cerium group either in the metallic state, or in the
nature of compounds such as oxides, fluorides, cyanides, carbides, alicates, or
other salts or of alloys, or a plurality of such substances may be used conjointly,
it being understood that these dephosphorizing agents may be employed either
by mixing them with the metal or by lining the furnace or converter with them
Dated this 6th day of June 1898
A. M. & WM CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
COMPLETE SPECIFICATION
Improvements in Processes of Dephosphorizing Steel and other
Metals.
I, JOIN GORDON, c/o Edward Johnston, Son & Co., Rua Sao Pedro, Rio de
Janeiro, Brazil, South America, Inventor, 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.-
-
My invention relates chiefly to the manufacture of iron and steel and has
for its object the removal of phosphorus therefrom, but the process may be used
also for dephosphorizing other metals, for instance copper
I have observed that in rock-forming magmas, slags, etc., the phosphorus
present seeks by preference over other substances the rarer earths and their
metals, forming monazite, xenotime and other similar phosphates.

page_text: I have also found in the manufacture of steel by the basic or lime process
that while most of the phosphorus present combines with the lime, some still
remains in the molten metal, and that it is possible to remove a further
amount, if not all, by using the rarer earths or their metals, or the carbides,
fluorides, cyanides, silicates, or other salts of such metals, or mixtures of these
compounds These metals, oxides and carbides possess a stronger affinity for
phosphorus than lime or magnesia
My invention therefore consists in causing to re-act with the molten metal
containing phosphorus, either the larer earths, or their metals or the carbides
or other compounds thereof, or two or more of these substances, all as hereinafter
described and claimed.
6
"
It is well known that by the term rater earths
of corium, lanthanum, didymium, erbium, terbium, thorium, yttrium, holmium,
are designated the oxides
samarium and others, in fact the usual bases of the minerals monazite, xeno-
time and allied phosphates. These metals are also termed the metals of the
cerium group.
In dephosphorizing iron or steel, I cause to react with the molten metal the
oxides of the rarer elements above defined, or these elements themselves in a
metallio state, or as carbidos This treatment is applicable and effective with
the
open hearth
process as well as with the Bessemer or basic
also employ as dephosphorizing agents, alloys or compounds of the metals of
I may
process
the cenum group or of then carbides, with iron or with iron and manganese
(ferio-manganese) forming new metals or alloys I find that by applying these
elements as oxides or in the metallic state, or as carbides, etc, especially when
previously alloyed with iron, or ferro-manganese, I effect a more intimate union
with the phosphorus contained in the iron or steel and facilitate the combina-
tion, the result being the slagging off of the phosphorus as phosphides or
phosphates
It will be understood that the quantity of the dephosphorizing agent will
depend on the amount of phosphorus contained in the metal to be dephospholized
and on the nature (chemical equivalent) of the said agent
phosphorus 18 determined by an analysis, say of the pig iron, and the quantity
The percentage of
of oxide required is a mere matter of calculation in the manner well known
to metallurgical chemists Thus, for cenum oxide, the quantities, calculating
by the chemical equivalents, will be in the proportion :
so that roughly speaking the quantity of the oxide would be about five to six
times the percentage of phosphorus determined by analysis in the pig iron of
the charge
As hereinbefore stated, the process is applicable to the dephosphorizing of any
metal, the operation being,substantially the same in all cases, namely, con-
sisting in the production of a reaction between the above defined dephosphorizing
agents and the molten metal
It will be understood that I employ as dephosphorizing agents the metals
of the rarer earths, or of the cerium group, either in the metallic state, or in the
nature of compounds such as oxides, fluorides, cyanides, carbides, silicates or
other salts or of alloys, or a plurality of such substances may be used conjointly.
The claim hereunto appended is to be read and interpreted accordingly it being
understood that these dephosphorizing agents may be employed either by
mixing them with the metal, oi by lining the furnace or converter with them
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim 18
-
The herein described method of dephosphorizing metals, which consists in

page_text: subjecting the metal in fusion to contact with, and the chemical action of, the
metals of the rarer earths, or of the cerium group, either in the metallic state
or in the form of oxides, fluorides, cyanides, carbides, silicates or other salts,
or in the form of alloys or compounds, substantially as specified.
Dated this 21st day of February 1899.
A. M & WM CLARK,
Chartered Patent Agents, 53, Chancery Lane, London