Improvements in or relating to the Manufacture of Iron and Steel.
Year: 1892

page_text: Date of Application, 13th Sept., 1892
Complete Specification Left, 13th June, 1893-Accepted, 9th Sept., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Manufacture of Iron and Steel.
I, GEORGE FREDERICK THOMSON, of Quendon, Newport, in the County of
Essex, Gentleman, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an improved process for manufacturing iron and steel
and while it is particularly applicable to the puddling furnace it may equally well
be applied to the blast furnace or to any of the steel processes.
By my invention I am enabled to utilize a very inferior quality of pig iron known
as "cinder pig" containing a large proportion of phosphorus, sulphur, and other
impurities.
My invention consists in the application of small quantities of aluminium to the
puddling or other furnace or converter at certain intervals either alone or in combina-
tion with lime and manganese or ferro manganese or other oxides which are commonly
added to the puddling process and I have found that the aluminium has the effect of
lowering the melting point of the iron, increasing its fluidity, and imparting to the
rolled bars breaking strain and elasticity nearly equal to that of steel.
It will be understood that I do not limit myself to the use of cinder pig, as the
invention is applicable to all kinds of iron and steel.
Dated this Thirteenth day of September 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Iron and Steel.
I, GEORGE FREderick ThomsON of Quendon, Newport, in the County of
Essex, Gentleman, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by.
the following statement :-
This invention relates to improvements in the manufacture of iron and steel and
consists in the addition at intervals of small quantities of aluminium and some-
times of lime or other suitable basic materials all in the manner hereinafter
described. The invention is particularly applicable to the process in the puddling
furnace but it may also be applied to the Siemens basic or acid process.
Instead
of aluminium I may use aluminium alloys.
When my invention is applied to the puddling process I am enabled to use
very cheap classes of pig iron and fetling and yet obtain a very good quality of iron
therefrom, a result not I believe heretofore attained.
"
When I use the quality of pig iron which I as yet have found most suitable for
my process, namely "Northampton common white or similar pig iron I also effect
a saving of time and fuel.
The iron obtained by my process with such qualities of pig iron moreover
exhibits superior qualities as to regularity of tensile strength, elongation and
bending and welding. Plates made by my process will stand much higher tensile
strains across the grain by making them much closer in texture.
According to this my invention as applied to the puddling process, notably in
the ordinary puddling furnace and in the rotary furnace, I add at certain periods
small quantities of aluminium and sometimes lime, by preference slaked, or other
וגע

page_text: suitable basic materials. The quantities of aluminium and of lime and the
periods at which they are added depend upon the composition of the pig iron
to be treated.
The total quantity of lime to be added should be about 2 to 3 pounds per pound of
phosphorus contained in the charge of pig iron, and the total quantity of aluminium
to be added should be about 4 to 6 ounces per charge of 500 pounds of pig iron.
If the percentage of phosphorus is lower than about 15 the lime may be charged
along with the pig iron, and the aluminium should be added just before "the boil"
takes place.
If the pig iron contains about 1-6 to 18 per cent. of phosphorus, then balf the
lime may advantageously be added when the pig iron is charged, and the remainder
when the metal is melted.
If the pig iron contains a still higher percentage of phosphorus, as for instance
the pig iron used in the basic process, then I increase the quantity of aluminium by
one or more ounces, say from 7 to 12, as required by the quality of the metal,
and add the aluminium at a somewhat later stage, or ordinarily towards the end
of the boil.
If stronger or harder iron is required in bars exposed to tensile strain, then I can
by my invention obtain such from phosphoric iron by adding the aluminium at an
carlier stage of the puddling process that is to say, just before, or in the early part
of the boil, and in larger quantities say from 7 to 14 ounces per charge of
500 pounds. By this treatment I retain a certain amount of the phosphorus which
acts as a hardening agent in the finished product because the aluminium in some
way counteracts the deteriorating influence of the phosphorus and renders it useful.
The aluminium when thus added quickens the process of puddling and by so doing
impedes the elimination of the phosphorus, so that it cannot be all removed and
counteracts the deteriorating effect in the final product making it less brittle and
more flexible.
When working with Northampton common white and similar pig iron in the
manner described a considerable saving in time is effected. This shortening of
time is due to the aluminium lowering the melting point of the iron and also to
its action on the combined carbon. The molten metal thus becomes very thin fluid
and the aluminium in the presence of the lime or other basic material thus helps
to free the iron from impurities. The lowering of the melting point also
facilitates the elimination of phosphorus and allows of "slack" being used for fuel
instead of coal.
Any of the materials known as "physic" (such for instance as ferro-manganese,
salt, chloride of calcium or fluorspar) may be added in conjunction with the
aluminium, or before, or after it, as desired.
As regards the Siemens basic process I find that by adding aluminium in small
quantities that is to say about 4 to 6 ounces in all per 500 pounds of metal, some
little time say from one to three hours after the pig iron and scrap have melted,
I am enabled to bring the metal to the requisite condition for casting much sooner
than can otherwise be done, thus effecting a saving of time and fuel besides
materially helping to free the metal from sulphur and phosphorus. I have generally
found 6 ounces as stated sufficient but in some cases more must be added or the
same quantity as stated only a little later, the condition of the molten metal being
the guide. If an excess of iron ore or iron ore and cinder is placed on the bottom of the
furnace before charging the aluminium may be added soon after the metal has
melted and a still greater saving of time is effected and the danger of over oxidation
is avoided. A small quantity of slaked lime may be added with advantage about
half an hour after the metal has melted.
With regard to the open hearth acid process I add the same quantity of aluminium
(about 4 to 6 ounces to 500 lbs. of metal) about hour to an hour after the metal
has melted, which has the effect of bringing the molten metal to the requisite
condition for casting much sooner than can now be done. In some cases the
aluminium may be added later or earlier the condition and heat of the molten metal

page_text: being the only guide. The aluminium may be added if desired in larger
quantities.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. In the puddling and similar processes the application of aluminium or
aluminium alloy with or without lime or other suitable basic materials substantially
in the manner and for the purposes set forth.
2. In the Siemens basic process and similar processes the application of aluminium
or aluminium alloy substantially in the manner and for the purposes set forth.
3. In the Siemens acid process the addition of aluminium or aluminium alloy
substantially as and for the purpose set forth.
4. The utilization of cheap or inferior classes of pig iron for the production of
superior qualities of malleable iron by the addition to the iron in the puddling
furnace of aluminium or aluminium alloy during the decarbonizing or puddling
process and in the presence of lime or other suitable basic materials substantially
as set forth.
5. The utilization of phosphoric pig iron for the production of hard and strong
qualities of malleable iron which nevertheless contain an appreciable percentage of
phosphorus by the addition to the iron in the puddling furnace of aluminium or
aluminium alloy with or without lime or other suitable basic materials substantially
in the manner set forth.
Dated this 13th day of June 1892
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.