IMPROVED MATERIALS FOR & METHODS OF DECARBURATING CAST IRON & CONVERTING IRON INTO STEEL
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by Christopher Binks at the Office
of the Commissioners of Patents, with his Petition, on the 21st
June 1873.
I, CHRISTOPHER BINKS, of Parliament Street, Westminster, Chemist
and Metallurgist, do hereby declare the nature of the said Invention
for "IMPROVED MATERIALS FOR & METHODS OF DECARBURATING CAST IRON &
CONVERTING IRON INTO STEEL," to be as follows:-
The object of my Invention is to facilitate the decarburation of cast
iron for the production therefrom of malleable iron, steclified iron, and
cast steel by the application of materials hereunder specified, and by a
direct and continuous treatment of the metal, especially when the
decarburating and converting operations are conducted in rotating
furnaces.
1

page_text: Firstly. In applying and in the methods of applying to the cast metal
operated on a certain residual compound which is obtained from well
known operations used in manufacturing aniline, and which compound
consists chiefly of magnetic oxide of iron mixed with some azotised
carbonaceous matter.
Secondly. It consists in the like application of the said residual com-
pound when mixed with an alkaline carbonate, the carbonate of soda or
of potash or a mixture thereof. Before applying it to the metal I expel
from the residue all moisture or other vapourizable matter by exposing
it to the natural drying action of atmospheric air at ordinary tem-
peratures, or by the application to it of a moderate heat. Or previously
to its application to the metal I mix the crude residue with a solution of
the alkaline carbonate, and then subject this mixture to a moderate heat
in order to expel from it all water or other volatile matter. Or I grind
together the dried residue and the alkaline carbonate well dried. I
prefer in making these mixtures to use the alkali and the residue in the
relative proportions of from 2 to 3 parts of alkali to 100 parts of the
residual compound, or thereabouts.
When the object is to fully decarburize cast metal through the agency
of this residual compound in its normal or in its alkalized condition, and
to obtain malleable iron as the final product, I fuse the cast iron in any
convenient furnace or apparatus, but using preferably a rotating
puddling or reducing furnace, I then add this compound to and work it
into the molten iron till the reactions between the compound and the
carbon contained in the cast metal result in the complete or nearly
complete expulsion of the carbon, and consequent production of
malleable iron.
When the object is to produce steelified iron or partially converted
iron or an alloy of real steel and iron, then I suspend the addition of the
decarburizing compound at that stage of the operation, which leaves the
iron combined with the proportion of azotised carbon, which gives to the
product, the required steelified quality or converts it into semi-steel or
steeled iron. But if real steel, that is steel proper or steel in the form
of cast steel be the product finally required, then I add the reducing and
converting compound to the molten metal in quantity sufficient to

page_text: finally leave in combination with the iron from 1.25 to 1.5 per cent.
(or thereabouts) of azotised carbon, that is, in other words, I so regulate
the operations as to adjust the relative proportions of these elements
finally left in the metal to those proportions which constitute real
steel.