IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND FOR THE PREVENTION OF WASTE IN ITS PRODUCTION
Year: 1876

page_text: LETTERS PATENT to Frederick William Gerhard, of Coseley, in the County of
Stafford, Metallurgical Chemist, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF IRON AND STEEL, AND FOR THE PREVENTION OF WASTE
IN ITS PRODUCTION.”
Sealed the 30th September 1876, and dated the 14th June 18'
PROVISIONAL SPECIFICATION left by the said Frederick William Gerhard
at the Office of the Commissioners of Patents on the 14th June 1876.
"
FREDERICK WILLIAM GERHARD, of Coseley, in the County of Stafford, Metal-
lurgical Chemist. 'IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL,
AND FOR THE PREVENTION OF WASTE IN ITS PRODUCTION."
According to my Invention in the manufacture of cast iron I employ (by
preference) what I term a compound flux known as basalt (of a greyish black color)
or green rock, diorite, igneous rock, or trap. All the above containing silica,
alumina, and lime (which is the basis of what I require), and in addition in varying
proportions manganese, soda, potash, and iron. This is to be used by preference in
a blast furnace with, if required, an additional quantity of carbonate of lime or oxide
of calcium with ores known as hematites or magnetites (oxides of iron) with the
necessary proportion of carbon. But I do not exclude the use of any description of
iron ores or silicates of iron with the above flux. Should the ores or silicates of iron
contain a large per-centage of phosphoric acid I employ high pressure steam
occasionally during its calcination, or to use it in a similar manner in a blast
furnace.
To melt cast iron for foundry furnaces, I line the cupola or furnace with a
mixture of silicate of alumina and lime (which I term a mixture) instead of the
usual way with sand. Or I add to the cast iron to be melted the necessary quantity
of the compound flux with carbonate of lime, which prevents the formation of
silicate of iron.
To produce wrought iron from cast iron, I employ the puddling furnace as at
present constructed, but I substitute for the lining now generally used the above
compound flux ground, and if required I add carbonate of ground lime or oxide of
calcium to the above, or if inore convenient a mixturo of silicate of alumina and
oxide of calcium, which prevents the production of silicate of iron.
The mill or reheating furnace to be treated in a similar way by substituting the
above compound flux or the above mixture for the sand or other material which is at
present employed.

page_text: For the direct way of producing wrought iron from hematites, magnatites, iron scale,
or other oxides and silicates of fron The ores to be finely ground and mixed with
silicate of alumina and lime, to which is added the requisite proportion of carbon,
either ground coke, coal, anthracite, or steam coal, pitch or tar to be well mixed
with water, dried or compressed in any convenient way. The iron scale to be
treated in a similar way. The silicates of iron (locally termed top and flue
cinder to be by preference calcined and steamed, then ground and mixed as above.
To produce puddle steel, I select by preference clean iron scale, to be mixed as
above with the requisite proportion of carbon and the oxide of manganese or
manganiferous ore. If scale cannot be readily obtained I substitute hematite or
magnetites ores to be treated in a similar manner. For the sides and bottom of
puddling and reheating furnaces a thick block of basalt could be substituted for fire-
bricks, which would assist in the prevention of silicate of iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick William Gerhard in the Great Seal Patent Office on the
13th October 1876.
<
FREDERICK WILLIAM GERHARD, of Coseley, in the County of Stafford, Metallurgical
Chemist. IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND FOR
THE PREVENTION OF WASTE IN ITS PRODUCTION."
According to my Invention in the production of cast iron I employ what I term
a compound flux, named by mineralogists and others as basalt (of a greyish black
color), green rock, diorite, igneous rock, and trap, all containing silica, alumina, and
lime in varying proportions, and in addition generally manganese, soda, potash, and
iron. This is to be used by preference in a blast furnace with, if requisite, an
additional quantity of carbonate of lime or oxide of calcium with ores known as
hematites or magnetites (oxides of iron) with the necessary proportion of carbon,
but I do not exclude the use of any description of iron ores or silicates of iron with
the above flux should the ores or silicates of iron contain phosphoric acid. I calcine
them in heaps, mounds, or appropriate furnaces, and construct the heaps, mounds,
or furnaces so that high pressure steam can be conveyed occasionally into the
mounds or furnaces during its calcination, or, if more convenient, into the blast
furnace when smelting the ores at intervals.
To melt cast iron for foundry or other purposes I line a cupola furnace with a
mixture of silicate of alumina and lime. Or I add to the cast iron to be remelted
the necessary quantity of the basalt flux with, if required, an additional quantity
of carbonate of lime, which prevents the formation of silicate of iron.
To produce wrouglit iron from cast iron I employ the puddling furnace as at
present constructed, or any other form more convenient. The above-mentioned
compound flux or basalt as a protection for lining the bottom and sides of a
puddling furnace prepared in the usual way with or without an addition of silicate
of alumina and lime (the fusubility of the slag can be regulated by the quantity of
lime employed), which prevents the production of silicate of iron.
The mill or reheating furnace or any other description of furnace employed in
the manufacture of iron to be prepared in a similar manner instead of sand or other
materials which are now employed.
For the direct mode of producing wrought iron from hematites, magnetites, iron
scale, silicates of iron, or any other description of ores. The ores to be finely
ground (when required) and mixed with silicate of alumina and lime in sufficient
proportions to cause it to adhere, to which is added the requisite proportion of
carbon either ground coke, coal dust, anthracite, steam coal, pitch or tar to be
well mixed with water dried or compressed in any convenient way. The propor-
tion of carbon must depend entirely on the per-centage of iron contained in the

page_text: ores. If the ores contain 60 per cent. of iron 19 to 25 parts carbon are required,
if 50 per cent. of iron 16 to 20 of carbon, and if 40 per cent. of iron in the ores
13 to 16 of carbon or thereabouts.
The silicates of iron (locally termed tap and flue cinder,) which I have termed
waste, to be by preference calcined as above with the addition of high-pressure
steam mixed with silicate of alumina and lime, and treated in the same way as the
ores above mentioned to produce wrought iron from cast iron in a lined puddling
furnace.
To produce puddled steel I select by preference clean iron scale, to be mixed as
above with the requisite proportion of carbon, 21 to 22 per cent. of carbon is
sufficient, and oxide of manganese or ground manganiferous ores. The proportion
of manganese to be ascertained by experiment on a small scale; if scale cannot be
procured hermatite or any other description of ore to be treated in a similar way to
the scale in a lined puddling furnace.
Having now set forth the nature of my Invention I wish it to be understood
that I claim the processes above described, whereby I am enabled by the use of
fluxes containing silica, alumina, and lime, and occasionally manganese, soda, potash,
and iron to be found in basalts, and also silicates of clumina and lime, which can
be, when required, intermixed with basalt or other minerals containing silica,
alumina, and lime, or silica, alumina, and iron which lime can be added to prevent
the waste of iron and steel in its production.
In witness whereof, I, the said Frederick William Gerhard, have hereunto set
my hand and scal, this Twelfth day of October, in the year of our Lord
One thousand eight hundred and seventy-six.
FREDERICK WILLIAM GERHARD. (L.S.)