IMPROVEMENTS IN THE TREATMENT OF HEATING, PUDDLING, AND REFINERY IRON SLAGS OR CINDERS
Year: 1855

page_text: LETTERS PATENT to Frederick Crace Calvert, of the City of Manchester,
in the County of Lancaster, Professor of Chemistry, for the Invention of
"IMPROVEMENTS IN THE TREATMENT OF HEATING, PUDDLING, AND REFINERY
IRON SLAGS OR CINDERS."
Sealed the 13th November 1855, and dated the 1st September 1855.
PROVISIONAL SPECIFICATION left by the said Frederick Crace Calvert
at the Office of the Commissioners of Patents, with his Petition, on the
1st September 1855.
I, FREDERICK CRACE CALVERT, of the City of Manchester, in the County of
Lancaster, Professor of Chemistry, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE TREATMENT OF HEATING, PUDDLING, AND
REFINERY IRON SLAGS OR CINDERS," to be as follows:-
My object is the production of a better quality of cast and malleable iron
from certain iron slags or cinders, known by the names of heating, puddling,
and refinery iron slags or cinders, than is effected at the present day, and to
obtain this from such slags or cinders, not only on blast furnaces or the like
places now in common use, but also on an ordinary cupola or other suitable
furnace or place. My first mode of treating such slags or cinders is as
follows: After the iron balls or blooms have been taken out of the puddling

page_text: furnace, or other place where they have been heated, I introduce into such
puddling furnace, or other place which still contains the hot slags or cinders,
one-half of their weight of quick lime, or nearly two-thirds their weight of
slacked lime, carbonate of lime, limestone commonly used in blast furnaces, or
magnesian limestone; and after this mixture of the lime and slags or cinders
has been well stirred, so that the lime or magnesia is united with the slags or
. cinders, the mass is removed in the usual way and allowed to cool.
Secondly, I take heating, puddling, or refinery slags or cinders, and intro-
duce them into a heated puddling furnace, or any other suitable furnace or
place, and melt them with about one-half their weight of quick lime, or two-
thirds of their weight of slacked lime, carbonate of lime, limestone commonly
used in blast furnaces, or magnesian limestone. When the mass is well
melted, and the lime or magnesia thoroughly united with the slags or cinders,
I then remove it in the usual way, and allow it to cool.
Thirdly, I mix heating, puddling, or refinery slags or cinders with one-half
to two-thirds their weight of quick lime, slacked lime, carbonate of lime,
limestone commonly used in blast furnaces, or magnesian limestone, and intro-
duce them into a crucible or other suitable vessel, which I then place in a
heated furnace or other convenient place; and when the mixture is well
melted, I remove it out of the crucible or other suitable vessel, and allow it
to cool.
After I have prepared the mixtures of lime and magnesia and slags or
cinders as above described, I introduce such prepared slags or cinders into a
cupola blast furnace, or other suitable place, and proceed to extract the iron
which they contain, by melting them in contact with coke if it is in a cupola
or such like place with coke, or in contact with coal, coke, limestone, and
mine, if in an ordinary blast furnace or such like place.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Crace Calvert in the Great Seal Patent Office
on the 29th February 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
CRACE CALVERT, of the City of Manchester, in the County of Lancaster,
Professor of Chemistry, send greeting.
WHEREAS IIer most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of September, in the year of our Lord

page_text: One thousand eight hundred and fifty-five, in the nineteenth year. of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Frederick Crace Calvert, Her especial license that I, the said
Frederick Crace Calvert, my executors, administrators, and assigns, or such
others as I, the said Frederick Crace Calvert, 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 of Man, an Inven-
tion for "IMPROVEMENTS IN THE TREATMENT OF HEATING, PUDDLING, AND REFINERY
IRON SLAGS OR CINDERS," upon the condition, amongst others, that I, the said
Frederick Crace Calvert, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said Inven-
tion, 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 Frederick Crace Calvert, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement (that is to say):-
My said Invention consists in improvements in the treatment of heating,
puddling, and refinery iron slags or cinders, and is as follows:-It is well
known that the slags or cinders above named contain a large amount of silicious
matter, as well as sulphur, phosphorus, and arsenic, which very much injure
the quality of the iron they contain and the iron they come in contact with,
when they are smelted with other iron ores in furnaces.
By the employment of quick lime, slacked lime, carbonate of lime, lime-
stone commonly used in blast furnaces, or magnesian limestone, and the use
of heat, and after the union of such substances with the slags or cinders, I
smelt them not only on blast furnaces or the like places now in common use,
but also in ordinary cupolas or other suitable furnaces or places, so as to
extract from them a better quality of iron than has been hitherto obtained.
My first mode of treating such slags or cinders is as follows:-After the iron
balls or blooms have been taken out of the puddling furnace, or other place
where they have been heated, I introduce into such puddling furnace, or other
place which still contains the hot slags. or cinders, a quantity of quick lime,
slacked lime, carbonate of lime, limestone commonly used in blast furnaces, or
magnesian limestone, broken into small pieces. The quantity of these material
which I use varies with the nature of the slags or cinders, but I find that the

page_text: lime or magnesia should be supplied nearly in the proportion of two chemical
equivalents of lime or magnesia to one of silica existing in the slag sub-
mitted to my process. For ordinary puddling slags or cinders, I use from
fifteen to twenty-five per centum of quick lime, twenty to thirty per centum
of slacked lime, twenty-five to fifty per centum of carbonate of lime, limestone
commonly used in blast furnaces, or magnesian limestone; and after this
mixture of lime or magnesia and slags or cinders has been well stirred, so
that the lime or magnesia is intimately united with the slags or cinders, the
mass is removed from the furnace in the usual way and allowed to cool. The
above method I prefer to use when circumstances will permit, but I can
obtain the same results by allowing the hot slags or cinders to run from the
furnace in which they have been heated into a vessel containing the quick
lime, slacked lime, carbonate of lime, limestone commonly used in blast fur-
naces, or magnesian limestone, in the quantities above named, and I facilitate
the admixture of the substances by constant stirring. I can also allow the
slags or cinders from the heating furnace to collect in a receptacle placed at
the bottom of the flue of the heating furnace; and when a sufficient amount
of slag or cinder is collected therein, I run it out into a vessel and mix it with
quick lime, slacked lime, carbonate of lime, limestone commonly used in blast
furnaces, or magnesian limestone, in the quantities before named, and stir them
so as to mix them well together.
Secondly, I take heating, puddling, or refinery slags or cinders, and introduce
them into a heated puddling furnace, or any other suitable furnace or place,
and melt them with quick lime, slacked lime, carbonate of lime, limestone
commonly used in blast furnaces, or magnesian limestone, in the quantities
before named. When the mass has been well melted, and the lime or
magnesia thoroughly united with the slags or cinders, I then remove it in the
usual way and allow it to cool.
Thirdly, I mix heating, puddling, or refinery slags or cinders with quick
lime, slacked lime, carbonate of lime, limestone commonly used in blast
furnaces, or magnesian limestone, in the quantities before named, and introduce
them into a crucible or other convenient vessel, which I then place in a heated
furnace or other suitable place, and when the mixture has been well melted
together, I remove it out of the crucible or other suitable vessel, and allow it
to cool. Similar results may be obtained by heating the slags or cinders in
heaps or in kilns, or other such places, in contact with quick lime, slacked
lime, carbonate of lime, limestone commonly used in blast furnaces, or magne-
sian limestone, in the quantities above named, and after the slags or cinders
are united with lime or magnesia, the mass is allowed to cool and then removed

page_text: in the usual way. After I have prepared the slags or cinders by mixing them
well together with lime or magnesia by any of the methods before mentioned,
I introduce such prepared slags or cinders into a cupola, blast furnace, or other
suitable place, and proceed to extract the iron which they contain by smelting
them in contact with coke in a cupola or such like place, or in contact with
coal, coke, limestone, and mine, if in an ordinary furnace or such like place,
as is now in common use and well known.
I wish it to be clearly understood that I do not confine myself to any of
the above modes of operating; but what I claim is, the mixing of heating,
puddling, or refinery iron slags or cinders with quick lime, slacked lime,
carbonate of lime, limestone commonly used in blast furnaces, or magnesian
limestone, so as to unite them by means of heat previously to the introduction
of such prepared cinders or slags into a cupola, blast furnace, or other suitable
place, so as to extract the iron they contain when fused in contact with a
carbonaceous fuel in a cupola, blast furnace, or other suitable place, and so
as to obtain a better quality of iron than has hitherto been done.
In witness whereof, I, the said Frederick Crace Calvert, have hereunto
set my hand and seal, this Twenty-eighth day of February, in the year
of our Lord One thousand eight hundred and fifty-six.
F. CRACE CALVERT. (L.S.)