able Iron or Steel, also Applicable for Analogous Purposes.
Year: 1885

page_text: able Iron or Steel, also Applicable for Analogous Purposes.
I EDWARD FLETCHER of South Stockton on Tees in the County of York Iron
Works Manager do hereby declare the nature of said Invention for “IMPROVEMENTS
IN THE TREATMENT OF PIG IRON FOR ELIMINATING IMPURITIES DURING THE
PROCESS OF ITS CONVERSION INTO MALLEABLE IRON OR STEEL ALSO APPLICABLE
FOR ANALOGOUS PURPOSES," to be as follows:-
My Invention relates to the treatment of Pig iron or the Carbide of Iron in any
other form suitable for conversion into malleable Iron or Steel and has for its
object to produce a high quality of malleable iron or steel from inferior classes of
Pig Iron by eliminating such impurities as Silicon Phosphorus and Sulphur and is
especially applicable to the manufacture of malleable Iron by the ordinary process
of wet puddling but is also applicable for analogous purposes wherein the impurities
of the pig iron or other Carbide of Iron are eliminated in a furnace at a high
temperature by means of oxidizing agencies. My Invention also accelerates the
process of conversion in such furnaces and is therefore attended with less labour
and less waste of Iron than is usual under modes of treatment at present in use.
In carrying my Invention into effect I apply as a basic flux hammer scale with
lime, soda and salt in suitable quantities and proportions as for instance an
ordinary charge of a puddling furnace or about 4 cwt would be treated with
about 4 lbs of lime and 3 lbs each soda and salt but I vary the quantities and
proportions of these ingredients to suit the nature and quality of the iron and
general conditions under which it is treated These ingredients may be mixed
with ground slag such as is obtained from puddling or balling furnaces or they
may be mixed with purple or mill scale or other equivalent and suitable oxidizing
material that can be conveniently procured. In treating iron in the puddling
furnace by what is known as the wet process I prefer to apply the above basic
flux by throwing it onto the furnace bottom before charging the iron but it may
I Price Bd 1

page_text: also be applied by being mixed into the usual material with which the furnace is
fettled or may be conveyed through the door or stopper hole into the furnace
during the melting and working of the charge. In order to produce a soft tough
and ductile quality of Iron I prefer in some cases to introduce into the furnace in
which the iron is treated in conjunction with the above described basic flux
a certain proportion of Oxide of Manganese as for instance from 1 to 2 lbs for an
ordinary charge of Pig iron requiring 4 lbs of Lime and 3 lbs each of Soda and
Salt or an equivalent quantity of pure Oxide of iron or steel, or iron or steel
turnings borings or nippings.
T
1007

page_text: impurities during the Process of its Conversion into мaше-
able Iron or Steel, also Applicable for Analogous Purposes.
:
I EDWARD FLETCHER of South Stockton on Tees in the County of York Iron
Works Manager, 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 :-
My Invention relates to the process of converting pig iron into malleable iron or
steel or "puddled bars" by what is known as the process of wet puddling or pig
boiling and has for its object to produce from pig iron such as the pig iron
smelted from Cleveland ores and containing injurious proportions of silicon phos-
phorous and sulphur a quality of puddled bara capable of being made up into
ductile and fibrous merchantable Iron or steel of good quality by sufficiently
eliminating the above named injurious elements during the ordinary process of
decarbonising the iron in the puddling furnace. I effect the elimination of the above
injurious elements from the iron by the application of a basic flux as hereinafter
described with the result that the process of puddling such iron is accelerated
thereby saving labour fettling and fuel and where good fettling is used a better
yield of iron or steel is obtained.
In carrying my Invention into effect I add to the usual oxidising materials
employed in the puddling process for decarburising the pig iron a mixture of lime
soda and salt which I apply in the following ways and quantities; thus in treating
pig iron from the Cleveland ores which contains on an average 1-75 per cent of
phosphorous together with silicon and sulphur I employ in treating the usual
puddling furnace charge (of 4 cwt.) 4 lbs of lime and 3 lbs each of soda and salt
this may be applied by being mixed into the usual fettling, but as these materials
have a tendency to break up and destroy the fettling I prefer to mix them up
with the flux usually thrown on to the bottom or hearth of the furnace before
introducing the charge of pig iron which flux generally consists of from 84 to
112 lbs of hammer scale, or an equivalent quantity of steel or millscale ground
slag obtained from puddling or balling furnaces, or a mixture of these or their well
known equivalents, but I do not prefer to mix the lime soda and salt with purple
ore, as when purple ore is used the puddled bars are not so clean and pure in
composition as with other purer oxidising materials and therefore do not work up
into as good a quality or merchantable iron or steel. Instead of adding the
lime soda and salt to the hammer scale or other fluxing material and throwing the
mixture onto the puddling furnace or hearth before introducing the charge of pig
iron, the same quantities of lime soda and salt mixed with a small quantity of
rich flux (say about 14 lbs of steel or mill scale) may be introduced into the puddling
furnace through the stopper hole after the melting of the charge has taken place.
It is of course obvious that I can introduce the requisite quantities of lime soda
and salt into the furnace by any one of the above described methods, or if I prefer
to do so I can avail myself of each method introducing part of the mixture by

page_text: one method and the remainder by either or both of the others, my invention being
carried into effect by the combined agency of the purifying basic flux of lime soda
and salt added to the usual quantity of oxidising material.
•
By means of the above described purifying basic flux puddled bars may be
obtained from phosphoric pig iron like the pig iron of Cleveland sufficiently pure
to be manufactured into merchantable iron or steel of good quality, but where iron
of extra good quality is required I avail myself of the usual practice of adding to
the charge during the pig boiling process a small quantity of oxide of manganese,
as for instance from 1 to 2 lbs to the usual charge of 4 cwt. or an equivalent
quantity of pure oxide of iron or steel, or iron or steel in a minutely divided state
as borings, nippings turnings or a mixture of these materials.
By the terms lime soda and salt I mean the materials commonly known in
commerce by those names although of course their chemical equivalents in this
connection could be used except on the score of economy in the manufacture-The
quantities and proportions of the ingredients above described for making up my
basic flux are those which, are especially suitable for purifying Cleveland pig. iron
which contains on an average 175 per cent of phosphorous but the relative
quantities of these ingredients to each other and to the charge of pig iron under
treatment may be varied according to the relative proportions of silicon phosphorous
and sulphur contained in the pig iron if so desired 'although the quantities specified
for Cleveland pig iron can be used for all classes of pig iron, but where there is
less phosphorous than 1.75 per cent present the ingredients specified may be
reduced for economy's sake-In the very few cases where the per centage of phos-
phorous is higher than that specified the ingredients may be correspondingly
increased As the silicon and sulphur are more easily removeable than phosphorous
what is sufficient to remove the latter will answer for the removal of the silicon
and sulphur.
I am aware that numerous attempts have been made to produce high class
merchantable iron or steel from inferior or impure classes of pig iron and that the
purifying ingredients employed in my process are referred to in the Specifications
of Patents granted to various Inventors of different mixtures proposed for effecting
this purpose and that the manner of applying my purifying flux is also similar to
the manner of applying other mixtures to the material in reverbaratory or puddling
furnaces and I do not claim these features generally but I am not aware of any
process being used or described wherein is employed or proposed to be employed
the mixture of the purifying ingredients which when added to the usual
oxidising materials make up the basic flux as hereinbefore particularly explained.
Having now particularly described and ascertained the nature of my 'Inven-
tion and by what means the same may be carried into effect I declare that what
I. 'claim is
In the manufacture of malleable iron or steel from pig iron by the process of
wet puddling and for the purpose setforth the employment of a purifying basic
flux formed by an addition of lime soda and salt to the usual oxidising materials
the quantities of the lime soda and salt and the manner of applying them being
substantially as herein before described.
TI
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