IMPROVEMENTS IN CONVERTING CAST IRON INTO STEEL AND WROUGHT IRON AND PURIFYING CAST IRON FOR FOUNDRY AND OTHER PURPOSES
Year: 1872

page_text: LETTERS PATENT to James Henderson, of New York, in the United
States of America, but at present of No. 166, Buchanan Street,
Glasgow, in the County of Lanark, North Britain, for the In-
vention of "IMPROVEMENTS IN CONVERTING CAST IRON INTO STEEL AND
WROUGHT IRON AND PURIFYING CAST IRON FOR FOUNDRY AND OTHER
PURPOSES."
Sealed the 14th May 1872, and dated the 21st February 1872.
PROVISIONAL SPECIFICATION left by the said James Henderson at
the Office of the Commissioners of Patents, with his Petition, on
the 21st February 1872.
I, JAMES HENDERSON, of New York, in the United States of America,
but at present of No. 166, Buchanan Street, Glasgow, in the County of
Lanark, North Britain, do hereby declare the nature of the said In-
vention of "IMPROVEMENTS IN
CONVERTING CAST IRON INTO STEEL AND
WROUGHT IRON AND PURIFYING CAST IRON FOR FOUNDRY AND OTHER PURPOSES,"
to be as follows, that is to say:—
This Invention has for its object to remove silicon, sulphur, phos-

page_text: phorus, and carbon from crude or cast iron in such quantities as are
required in order to convert the same into steel or wrought iron, or to
purify it to any desired extent for foundry and other purposes, and it
consists in the employment for that purpose of fluor-spar, or artificial
fluoride of calcium, fluo-silicate of lime, cryolite, or the fluoride of
sodium and aluminium, with other substances as herein-after set forth;
these substances being such as evolve oxygen and acids which act upon
the metallic base of the fluorides or fluo-silicate of lime, thus liberating
the fluorine to react with the impurities.
According to the first part of this Invention either of the fluorides
herein-before mentioned, excepting the fluo-silicate of lime, are used
in combination or admixture with silica or quartz, or in combination
or admixture with silicate of alumina or clay, and these combined or
admixed substances are applied to the cast iron either in reverberatory
furnaces, cupolas, refineries, or other receptacles capable of containing
molten iron as a covering or lining for the sole or hearth, or sides of
such furnaces or receptacles. Both the fluorides and the silica or silicate
should be pulverized and spread over those portions of the furnaces or
receptacles which are about to be occupied by the molten crude iron,
this being charged upon the mixed fluorides and silica or silicates.
When the molten iron comes in contact with the fluorides and silica
or silicate chemical reactions take place between the elements of the
fluorides and those of the silica or silicate, and the silicon, carbon,
sulphur, and phosphorus in the molten iron; these latter becoming
removed in the form of vapour, or slag, or both. The amounts of
silicon, carbon, sulphur, and phosphorus thus removed will depend
upon the quantity of fluorine which the fluorides are capable of
evolving and silica or silicates used, the quantities of these used at any
time being dependent upon the quantities of the substances to be
removed from the molten crude iron, according as it is intended to
convert it into wrought iron or steel or purify it as cast iron, the
quantity however being also in the ratio of the chemical equivalents
of the elements which react on each other. The conditions necessary
to secure the conversion or purification are that the fluorides and
silica or silicate are placed in admixture with the iron, or applied so
as to act upon it from below upwards.
It is further to be understood that in place of pouring molten crude

page_text: iron upon the substances as herein-before described, pig, or cast iron,
or granulated iron may be melted thereon and puddled or boiled.
According to the second part of this Invention either of the fluorides
herein-before mentioned, including the fluo-silicate of lime, are used in
combination or admixture with carbonates, these being the carbonates
of iron not having or deprived of coaly matter, carbonate of lime, or
dolomite, or the carbonate of lime and magnesia, carbonate of magnesia,
or the carbonate of manganese, and carbonate of baryta, the said fluo-
rides or the fluo-silicate of lime may also be used in combination with
sulphate of iron or copperas, and sulphate of lime or gypsum, also with
alum and sulphate of alumina, also with sulphate of potash, sulphate of
soda, sulphate of baryta, sulphate of lime, sulphate of magnesia, and
sulphate of manganese in reverberatory furnaces, refineries, cupolas,
or other receptacles in the same manner that the fluorides in com-
bination or admixture with silica and silicate of alumina are herein-before
described. .
Another part of this Invention consists in the combined or admixed
use of fluor-spar, or artificial fluoride of calcium, cryolite, and the fluo-
silicate of lime with titaniferous iron ores, or oxides of titanium, oxides
of manganese, or chrome iron ores, or wolfram to convert cast iron into
steel or wrought iron or purify it for foundry and other purposes, in any
of the modes herein-before described.
It is also to be understood that cryolite may be used with other ores
or oxides of iron. In purifying molten iron in vessels where there is no
fuel the sulphate of ammonia, sulphate of alumina and potash, sulphate
of alumina and ammonia, and the sulphate of chromium and potash
may be used to react with the fluorides or fluo-silicate.
Lastly, it is to be understood that the conversion or purification of
molten, crude, or cast iron in the manner herein-before described may
be effected not only by the combination or admixture of any one of the
fluorides with the other substances mentioned, but that mixtures of the
said substances may be used with mixtures of the fluorides, care being
taken to employ the proper proportions of such substances and the fluo-
rides as will remove the impurities from the molten, crude, or cast iron,
the quantities being dependent, as already stated under the first head of
this Invention, upon the chemical equivalents of the elements contained

page_text: in the substances employed, and the several substances herein-before
mentioned, namely, oxides, silicate of alumina, carbonates, and sulphates
are substitutes for each other in treating cast iron in combined or
admixed use with fluorides or fluo-silicate of lime, as herein-before
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Henderson in the Great Seal Patent
Office on the 10th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HENDERSON, of New York, in the United States of America, but at
present of No. 166, Buchanan Street, Glasgow, in the County of Lanark,
North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of February, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Henderson, Her special license
that I, the said James Henderson, my executors, administrators, and
assigns, or such others as I, the said James Henderson, my executors,
administrators, or assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN CONVERTING CAST IRON INTO STEEL AND WROUGHT IRON AND PURIFYING CAST
IRON FOR FOUNDRY AND OTHER PURPOSES," upon the condition (amongst
others) that I, the said James Henderson, my executors or adminis-
trators, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Henderson, do hereby
declare the nature of my said Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in
and by the following statement, that is to say :-
This Invention has for its object to remove silicon, sulphur, phos-
phorus, and carbon from crude or cast iron in such quantities as are
required in order to convert the same into steel or wrought iron, or to
purify it to any desired extent for foundry and other purposes; and it
consists in the employment for that purpose of fluor-spar, or artificial
fluorides of calcium, fluo-silicate of lime, cryolite, or the fluorides of
sodium and aluminium with other substances as herein-after set forth;
these substances being such as evolve oxygen and acids which act upon
the metallic base of the fluorides or fluo-silicate of lime, thus liberating
the fluorine so as to enable it to react upon the impurities contained in
the crude or cast iron.
According to the first part of this Invention either of the fluorides
herein-before mentioned, excepting the fluo-silicate of lime, are used in
combination or admixture with silica or quartz, or in combination or
admixture with silicate of alumina, or with clay, and these combined
or admixed substances or the fluo-silicate alone, are applied to the cast
iron either in reverberatory furnaces, cupolas, refineries, or other recep-
tacles capable of containing molten iron as a covering or lining for the
sole, or hearth, or sides of such furnaces or receptacles. Both the
fluorides and the silica or silicates should be pulverized or reduced to a
fine state of division, and be spread over those portions of the furnaces
or receptacles which are about to be occupied by the molten, crude, or
cast iron.
When the molten, crude, or cast iron comes in contact with the
fluorides and silica or silicates chemical reactions take place between
the elements of the fluorides and those of the silica or silicates, and the
silicon, carbon, sulphur, and phosphorus originally contained in the
molten, crude, or cast iron; these latter being removed in the form of
vapour, or of slag, or both. The amount of silicon, sulphur, and phos-
phorus thus removed will depend upon the quantity of fluorine which
the fluorides employed are capable of evolving, and also upon the
amount of the silica or of the silicates employed, the proportion of
these used at any time being dependent upon the quantities of the
impurities to be removed from the molten, crude, or cast iron according
as it is intended to convert the crude or the cast iron into wrought or
malleable iron, or into stecl, or to obtain a purified cast iron therefrom.

page_text: The conditions necessary in order to secure the conversion of the
crude or cast iron into iron or steel, or the purification of the crude
or cast iron, are that the fluorides and the silica or the silicates are
placed in admixture with the crude or cast iron, or applied so as to act
upon it from below upwards.
It is further to be understood that in place of pouring molten, crude,
or cast iron upon the substances as herein-before described, pig or cast
iron in a state of division or granulated may after admixture be melted
therewith so as to obtain the desired result.
According to the second part of this Invention either of the fluorides
herein-before mentioned, including the fluo-silicate of lime, may be used
in combination or admixture with carbonates, such as the carbonates of
iron, carbonate of lime, dolomite or the carbonate of lime and magnesia,
carbonate of magnesia, or the carbonate of manganese, and carbonate of
baryta.
Another part of the Invention consists in the combined use of the
fluo-silicate of lime with titaniferous iron ores, or with oxides of
titanium, or with oxides of manganese, or with chrome iron ores,
or with wolfram in order to convert crude or cast iron into steel or
wrought iron, or in order to purify the crude or cast iron for foundry
or other purposes, by any of the modes herein-before described.
The proportions in which I prefer to employ the substances and
compounds herein-before mentioned will depend upon the amount of
impurities contained in the crude or cast iron to be operated upon, and
the degree of purity it is desired the products should attain.
In carrying out the first part of this Invention the proportions which
I have found to produce good results when cast iron, such for example
as Cleveland white pig iron, is to be operated upon are about from three
hundred to about five hundred parts by weight of fluo-silicate of lime
alone, or about from one hundred and eighty to two hundred and fifty
parts by weight of fluor-spar, and from about one hundred and eighty
to about two hundred and fifty parts by weight of silica or quartz, or
with about from one hundred and eighty to two hundred and fifty parts
by weight of fluor-spar, with an equal weight of silicates of alumina or
clay, to about two thousand parts by weight of cast iron, such for
example as Cleveland white pig iron.

page_text: In carrying out the second part of this Invention I prefer to employ
the fluor-spar in conjunction with the carbonate of manganese, or with
the other substances or compounds mentioned in the second part of this
Invention, in about the same proportions as those before mentioned
under the first part of this Invention.
In carrying out the third part of this Invention the fluo-silicate of
lime is employed in conjunction with titaniferous iron ores, or with
oxides of titanium, or with oxides of manganese, or with chrome iron
ores, or with wolfram. I prefer to employ the same in about equal
proportions by measure, namely, of the fluo-silicate of lime together
with equal parts by measure of the titaniferous iron ores, or with the
other substances and compounds referred to under the third part of my
Invention; such mixture I employ in about the proportion of seven
hundredweight to about one ton of crude cast iron, such as Cleveland
white pig iron, when the operation is conducted in boiling or in a
puddling furnace fettled in the usual manner with oxide of iron.
I wish it to be understood that I do not confine myself to the
methods before described, as the substances and compounds before
mentioned may be applied in any of the processes for preparing crude
cast iron either for foundry purposes or for the production of wrought
iron or steel.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before recited Letters Patent is,―
First. The treatment of crude or cast iron by the employment of the
fluo-silicate of lime alone, or of the fluorides herein-before mentioned
in conjunction with silica or quartz, or in conjunction with silicates of
alumina, or with clay, in the manner and for the purpose herein-before
mentioned.
Second. The treatment of crude or cast iron by the employment of
the fluorides herein-before mentioned, or of the fluo-silicate of lime in
combination with the carbonate of iron, carbonate of lime, dolomite or
carbonate of lime and magnesia, carbonate of magnesia, carbonate of
manganese, and carbonate of baryta, in the manner and for the purpose
herein before mentioned.

page_text: Third. The employment of the fluo-silicate of lime in conjunction
with titaniferous iron ores, or with oxides of titanium, or with oxides
of manganese, or with chrome iron ores, or with wolfram, in the
manner and for the purpose herein-before mentioned.
In witness whereof, I, the said James Henderson, have to this my
Specification set, my hand and. seal, this Ninth day of August
One thousand eight hundred and seventy-two.