IMPROVEMENTS IN THE UTILIZATION OF SLAGS
Year: 1879

page_text: LETTERS PATENT to Arthur Cooper, of Darnall, Sheffield, Engineer, for the
Invention of "IMPROVEMENTS IN THE UTILIZATION OF SLAGS."
Sealed the 7th May 1880, and dated the 13th November 1879.
PROVISIONAL SPECIFICATION left by the said Arthur Cooper at the Office
of the Commissioners of Patents on the 13th November 1879.
ARTHUR COOPER, of Darnall, Sheffield, Engineer.
UTILIZATION OF SLAGS"
"IMPROVEMENTS IN THE
This Invention relates to a method of utilising the calcareous slag produced
when treating phosphoretic pig iron in basic lined Bessemer converters with large
additions of lime, and at the same time producing a pig iron or metal highly suited
for treatment by what is known as the Thomas and Gilchrist Bessemer process.
This slag has hitherto been generally treated as a waste product. I however find
it may be very advantageously utilised by removing it preferaby while still hot,
and adding it to the charge of pig-iron in the cupola which is being used to melt
down the pig for treatment in the basic Bessemer vessel, instead of the limestone
which is ordinarily thrown into the cupola as a flux. In the same way this slag
may be mixed with a silicious burden and used in blast furnaces, particularly those
which are employed to produce the phosphoretic pig to be treated in the basic
Bessemer vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Arthur Cooper in the Great Seal Patent Office on the 11th May 1880.
ARTHUR COOPER, of Darnall, Sheffield, Engineer, "IMPROVEMENTS IN THE
UTILIZATION OF SLAGS."
This Invention relates to an improved process for utilizing the calcareous slag
produced when treating phosphoric pig iron in basic lined Bessemer converters with
large additions of lime, so as to produce a phosphoric pig iron or metal highly suited
for what is generally known as the Thomas and Gilchrist modification of the
Bessemer process.
This Bessemer slag has hitherto been treated as a waste product and carted away
to the rubbish tip. I have however found. that. it may be very advantageously
utilized and rendered of value by adding it in the proportion of from 3 to 5 parts
of slag to 100 parts of pig (preferably while still hot) to the charge of pig iron in
the cupola which is being used to melt down iron for treatment in the lime-lined
Bessemer vessel. By this means not only does it become unnecessary to add
limestone in the cupola, as is ordinarily done, which is in itself a very great
economy, but the metal is rendered more suitable for treatment by this process than
it would otherwise be. In order to render the slag more liquid I prefer to add
a little clay, silicious slag, or fluor spar. When cupolas are not used or blast
furnaces are near I mix this calcareous phosphoric Bessemer slag with silicious iron
ore or a mixture of iron ores with puddlers' tap cinder and smelt it in the ordinary
way. I so calculate the burden as to yield a slicious slag and use a highly heated
blast. In this way the greater part of the manganese and iron and much of the
phosphorous in the slag is recovered in the pig, while the lime acts instead of
limestone as a flux for the silica in the remaining portion of the furnace charge.
Having thus described the nature of my Invention, what I claim and desire
to secure by Letters Patent is, the herein described process for utilizing calcareous
Bessemer slags by using them in a cupola or blast furnace as a fluxing material, by
which I produce a quality of pig iron highly suited for treatment by the Bessemer
process in lime lined converters.
In witness whereof, I, the said Arthur Cooper, have hereunto set my hand
and seal, this Tenth day of May, in the year of our Lord 1880.