IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1866

page_text: LETTERS PATENT to John Cameron, of Mount Pleasant, Barrow-in-Furness,'
in the County of Lancaster, Analytical Chemist, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL."
PROVISIONAL SPECIFICATION left by the said John Cameron at the
Office of the Commissioners of Patents, with his Petition, on the 15th
August 1866.
I, JOHN CAMERON, of Mount Pleasant, Barrow-in-Furness, in the County
of Lancaster, Analytical Chemist, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL," to be,
as follows:-
Silicium and sulphur being well known as deteriorating elements when
present in pig iron intended for the manufacture of steel and malleable iron,
my Invention relates to removing these and other impurities, such as alumina.
For this purpose I form a flux of lime with carbonates of potash, soda, and
common salt (chloride of sodium), or I may use a certain proportion of any iron.
ore or oxide of the same metal or any other compound of the same which I find
most suitable to mix with the lime and the other ingredients so as to flux the
impurities. To the above-named ingredients or mixture of the same I add a
certain proportion of carbon in the form of ground charcoal, common coal, or
ground coke or sawdust, whichever I find most suitable for my purpose. I.

page_text: may use one or a mixture of the above-named substances, whichever I find
to be most useful and economical.
The conditions under which I use the above-named materials are as
follows: Before the pig iron is put into the melting furnace preparatory to
its being run into the converter I put a certain portion of my purifying flux
on the bottom and hearth of the said melting furnace under the pig iron to be.
melted, and as the metal is filled in I occasionally put in a quantity of the flux
till the whole is filled in, I then put some on the top of the pig iron, close the
door of the furnace, and raise the heat. Instead of lime I may use ground
limestone or any other compound of lime which I find suitable, but I prefer
lime which has been burned, as its action is more rapid. I also put a portion
of my purifying flux into the converter before the metal is run into it so that
any remaining impurities may be taken up and absorbed in the cinder. In
addition to the above substances named I may use fluor spar (fluoride of
calcium) or carbonate of baryta. When I use potash or soda I prefer using
them in the state of carbonates. I also put a certain portion of the above-
named substances into the furnace for melting the spiegl eisen to purify it
before mixing it with the iron. I can use any convenient form of furnace
for melting the pig iron in with the flux, cupola, blast, or reverberatory
furnace. Melting the iron with the flux gives a very pure metal for the
purpose of steel making or for making malleable iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Cameron in the Great Seal Patent Office on the
15th February 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
CAMERON, of Mount Pleasant, Barrow-in-Furness, in the County of Lancaster,
Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of August, in the year of our Lord One
thousand eight hundred and sixty-six, in the thirtieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said John
Cameron, Her special licence that I, the said John Cameron, my executors,
administrators, and assigns, or such others as I, the said John Cameron, my
executors, administrators, and 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

page_text: of Man, an Invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND
STEEL," upon the condition (amongst others) that I, the said John Cameron,,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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 John Cameron, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,,
to be particularly described and ascertained in and by the following statement
thereof, that is to say:-
Silicium and sulphur are well known as deteriorating elements when
present in iron used for the manufacture of steel or malleable iron by forcing
an air blast through the melted cast iron according to the Bessemer process...
My Invention relates to the removing these and other impurities, such as;
alumina.. For this purpose the following materials, either singly or combined,.
are employed as purifying fluxes, and I use them in the manner hercin-after:
described:-These materials are lime or limestone or other carbonate of
lime, carbonate of baryta, or carbonate of soda or potash, and common salt;
lime and baryta at a high heat have a strong affinity for silica and alumina,
and combining with them separate them from the iron to form a slag. Soda
and potash act in the same way and more energetically, but they are more
expensive. Common salt has the, property of decomposing the phosphides
and sulphides of iron, the chlorine of the salt taking up the phosphorus and
the sulphur and forming volatile compounds therewith,, which pass off during
the operations.. I prefer usually to employ a mixture of three parts of lime
and one part of common salt,, and to these materials (except when the flux is.
to be used in a blast furnace) I add, say, of a part of charcoal or coal dust,
as free as possible from injurious impurities.. Instead of lime I may use
ground limestone, but I prefer lime that has been burnt, commonly called
slaked lime, as its action is more rapid. I also. prefer. to. add to, the other
materials of the flux oxide iron ore. I use the red or the brown hæmatite in
such quantity that it may form one-fifth of the whole compound, it assists in
separating sulphur and silica from the iron. Fluor spar may advantageously
be added in the proportion of two parts. The conditions under which I use
the above materials are as follows:-Before the pig iron that is. to be con-
verted into stcel is put into the melting, furnace, which I will now suppose to
be a reverberatory furnace, I put a portion of the purifying flux on the

page_text: bottom or hearth of the furnace, (say, from one-half to two-thirds of the
weight of flux used I place under the pig iron to be melted,) and as the metal
is filled into the furnace I occasionally put in a quantity of the flux till such
time as the whole of the metal is filled in. I then put the remainder of the
flux on the top of the pigs of metal, close the door of the furnace, raise the
heat, and melt the metal in the usual way. I also put purifying flux into the
converter before the metal is run into it from the melting furnace, so that
any remaining impurities may be absorbed in the cinder or otherwise
eliminated. Further to insure the action of the flux on the metal I sprinkle
with it the runners from the tapping holes of the pig melting furnace to the
mouth of the converter where the metal flows into it. This I find useful in
protecting the melted metal from the siliceous materials generally composing the
runners. I also use the fluxes as a wash for the ingot moulds and the pot or
vessel which is lined with ganister into which the molten metal from the con-
verter is run after being blown. The action of the fluxes upon the metal is
to deprive it of those impurities, which impair the qualities of steel and
malleable iron made by the Bessemer process. I also employ the flux in the
purification of the speigel eisen used for the Bessemer steel in the melting
furnace, and I apply it to the runners leading from the melting furnace to the
mouth of the converter in the same manner as in the case of the pig iron. If
the melting furnace is a blast furnace I mix no carbon with the fluxes, the
carbon of the coke used as fuel in the melting of the pig iron being sufficient,
and the fluxes are fed in from time to time along with the metal. In
carrying out the process I need not use two furnaces for the melting of the
pig iron and spiegel eisen. If I only use one furnace I melt the spiegel eisen
along with the pig iron in the following manner:-I first put in the pig iron
with the proper quantity of the flux and melt it in the usual manner. I then
add to the melted pig iron in the same furnace the proportion of spiegel eisen
necessary to attain the required object, as heretofore. I add the spiegel eisen
fifteen or twenty minutes before the metal is tapped out and run into the
converter, the alloy of manganese and iron (spiegel eisen) being very easily
melted. The melting furnace may be either a blast or reverberatory furnace.
When I operate upon the common classes of pig iron, such as numbers two,
three, and four, I employ in the melting furnace about four hundredweights
of the flux to every five tons of iron. The fluxes in all cases should be
intimately mixed. If the combined silicium in the pig iron amounts to two
per cent., and the silica and alumina in the graphite are proportionately high,
then I employ the above-mentioned quantity of flux in the operation, and
even increase it if necessary. If the proportion of phosphorus and sulphur is

page_text: high in the pig iron operated on I increase the quantity of common salt in
the flux. When I operate on the better classes of iron that are more grey
I use less of the fluxes. When the pig iron contains only small quantities of
these impurities I only use two hundredweight of the flux in purifying five
tons of pig iron. In melting the spiegel eisen I employ sixty pounds of flux
to a ton of metal. In the wash which I employ for the ingot moulds and the
pot or vessel which is lined with ganister into which the metal is poured
after being blown I put ten pounds of flux to two gallons of water for the
ingot moulds, and ten pounds of the flux to one gallon of water for the
ganister lined vessel. I mix well and wash the ganister lining of the pot
over several times till it has received a good coat, and then dry it as is usually
done. The wash for the ingot moulds I put on in a similar manner, taking
care to keep it as free from siliceous matter as possible.
Having thus described the nature of my Invention, and the best means
with which I am acquainted for carrying it into effect, I would have it under-
stood that what I claim is, the employing as purifying fluxes during the
manufacture of steel and iron by the Bessemer process of lime, limestone,
and other carbonates of lime, carbonate of baryta, and carbonates of soda and
potash, iron ore, fluor spar, and common salt, in the manners herein-before
set forth.
In witness whereof, I, the said John Cameron, have hereunto set my
hand and seal, this Thirteenth day of February, in the year of our
Lord One thousand eight hundred and sixty-seven.
JOHN CAMERON. (L.S.)