IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Thomas Schoenberger Blair at
the Office of the Commissioners of Patents, with his Petition, on
the 22nd February 1869.
I, THOMAS SCHOENBERGER BLAIR, of Pittsburg, Pennsylvania, in the
United States of America, but now residing at the Tavistock Hotel,
Covent Garden, in the County of Middlesex, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF IRON AND STEEL," to be as follows:-
My Invention has reference to a new process for producing wrought
iron by intimately mixing with molten cast iron solid oxidizing sub-
stances, as described in the Specification to certain Letters Patent
granted to Charles Denton Abel, dated 23rd November 1868, No. 3565.
It is well known that a variety of results can be produced in the
crucible in the treatment of iron or steel with certain substances which
either enter into combination and form an alloy or act as detersives by
combining with and carrying off impurities, which would otherwise
remain to the detriment of the product; but when these same sub-
stances have been tried in any open treatment, as the blast furnace,
puddling furnace, etc., the results have been of little or no value.

page_text: By the process described in the above-mentioned Specification a new
method of bringing detersive agents and useful alloys into use is rendered
available, and my present Invention consists in one part in the employ-
ment of and mode of applying certain substances to be hereafter
described in the said process, which act either as detersives or as useful
alloys.
For such purposes I employ, firstly, manganese. In this case I take
any of the various oxides of that metal, according to economic advantage,
and reduce it to about the same degree of fineness to which the iron or
other oxide has been reduced that is to be employed in the manufacture
of the conglomerate or "pig bloom" by the aforesaid process. It may
be in the form of powder, but as it is important that it should be well
and evenly mixed through the ore it will be found desirable to have
the two materials of about an equal degree of fineness.
To determine the quantity of oxide of manganese that should be
employed it is best to commence with test mixtures whereby to
establish rules for the use of any particular materials that are to be
operated with. There is such a wide variation in the composition and
character both of the manganese and iron materials that no other
method is safe; but it may be stated in general terms that a good test
mixture to commence experimenting with is such as will give about one
per cent. of metallic manganese to the weight of metallic iron in the pig
bloom. This proportion can be varied according to the results obtained
from the tests. The mixing of the oxide of manganese and the iron ore
can be done by weighing or measuring off the desired proportion of each
and repeatedly turning them over with a shovel. The mixture is then
to be used precisely as if it were the ordinary oxidizing material
employed for making the pig bloom, and the latter is to be treated in
the ordinary way. It will be found that the iron produced is much
stiffer and closer grained than it would have been without the man-
ganese, that it contains less impurities, and that the cinder from it in
the heating of the pig bloom is a more valuable article for blast furnace
use, producing better iron.
Iron thus produced having a hardness not due to carbon, and being
thus capable of enduring the same heat as other iron, can be employed
advantageously in the manufacture of rails, tyres, and other articles in
which it is desirable from motives of economy or safety to use iron for
the body and steel or its equivalent for the wearing surface. All that is

page_text: needed is to compose the pile with the desired quantity and position of
hard iron, and it can be welded up, as is done with any ordinary pile
of one sort of iron. It can also be substituted for low steels generally,
for such purposes as call for density, hardness, fiue polish, and the like.
The iron so produced is also better adapted for use in the application of
pig bloom or pig scrap iron to the manufacture of steel. I also some-
times employ chromium in the place of manganese; the method of
applying this and the proportions employed are substantially the same
as above described with reference to manganese, and the result is a
hardening of the iron. As in the case of manganese any of the ores
may be used according to convenience of supply. Where iron is desired
to be "cold short" I employ phosphorus, using iron ores especially rich
in this substance, or phosphate of lime, or indeed any of the great
number of substances into which phosphorus largely enters and which
do not contain objectionable constituents. The treatment is substantially
as before described, except that in the heating of the pig bloom or pig
scrap care must be taken not to expose them to too great an amount
of heat. The reason is that the ordinary treatment of pig bloom
and pig scrap thoroughly performed takes out nearly or all the
phosphorus in iron. Hence in the present case if the heat be great
enough and sufficiently prolonged all the phosphorus would go into the
cinder, rendering it less valuable for blast furnace use, and the wrought
iron would be no better for the extra trouble of supplying the phos-
phorizing substance. With this substance test mixtures should be
commenced with such proportions as will yield about per cent. of
phosphorus to the weight of the iron. I employ furthermore alumina
as a detersive agent, the only care necessary being that it shall not
contain or carry with it a large proportion of silica. The latter does not
injure the quality of the iron (as it is nearly all removed in the ordinary
course of the process), but it carries off a portion of the iron into the
cinder, and besides this renders the cinder less valuable from its silicious
character. In this case I mix ordinary clay with the oxide to the extent
of about 3 per cent. to the weight of iron in the pig bloom. Fluorine
may be used by taking fluor spar and reducing it to the required
fineness. As this substance consists simply of fluorine and lime it
possesses the recommendation of adding no objectionable ingredient to
the cinder. As in the other cases the proportion must be determined
by the character of the materials employed, ore, pig iron, etc.; it should
be employed freely, commencing with about two per cent. to the weight

page_text: of metal. I also make use of chlorine by taking about 1 per cent. of
common salt and mixing it in its ordinary condition with the ore.
Before mixing the salt should be heated sufficiently to dry it well, and
after mixing the mass should be kept hot enough to prevent its becoming
sticky by the absorption of the moisture of the air.
Furthermore, I employ zinc as a valuable detersive agent for "red
short" materials. It can be used as it occurs in the mineral "frank-
linite," which contains it as an oxide combined with iron and manganese.
Any quantity of it may be used, as this mineral worked alone produces
iron of good quality.
I also produce a useful alloy by using the mineral "wolfram," which
contains tungsten, and which when incorporated in the "pig bloom"
will give up a part of this metal which, combining with the iron, will
increase its hardness, and also make it more desirable for use in steel
manufacture. The admixture of the mineral should be such as will
give about per cent. of tungsten to the weight of iron.
In the same way I produce an alloy of titanium and iron, the former
giving additional "body" to the latter. For this purpose I use the
mineral ilmenite" or other titaniferous ores of iron, adding such a
quantity as will give about per cent. of titanium to the weight of iron.
In the foregoing I have spoken only of using each chemical agent
separately, but this has only been done in order to indicate the method
of applying each. It is evident that combinations can be used whereby
to obtain results more desirable than any one of those ingredients alone
will afford. For example, the mixture sometimes introduced into the
puddling furnace known as "Schafhautl's powder" consists of 3 parts
(by weight) of oxide of manganese, 5 of salt, and 15 of clay, and of this
mixture 3 per cent. of the weight of cast iron is used in puddling. By
introducing the same compound in the same proportions to the iron
into the oxide prepared for making the "pig bloom ог "pig scrap" the
chemical effects so feebly or doubtfully realized in puddling are obtained
freely and regularly.
Although I have in the foregoing indicated certain proportions for the
admixture of the alloys or detersive agents, yet I in no way limit myself
to such proportions, as they may be variously modified according to
circumstances.

page_text: Several masses of "pig bloom," either with or without the admixture
of detergents or alloys, as above described, may be combined together
by welding to form one homogeneous mass of a size proportionate to that
of the article to be produced, for which purposes the "pig blooms" are
all first heated to a high degree in order to perfect their conversion
into wrought iron and to eliminate impurities, as described in the
before-mentioned Specification, and they are then welded together under
a steam hammer or otherwise, after which the combined mass, before
being allowed to cool down, may be reheated in the finishing mill, and
be at once passed through the rolling mill or otherwise treated to
produce the article required.