IMPROVEMENTS IN THE PURIFICATION OF METALS, AND ESPECIALLY IN THE MANUFACTURE OF CAST STEEL
Year: 1881

page_text: LETTERS PATENT to Sydney Pitt, of Sutton, in the County of Surrey, for an
Invention of "IMPROVEMENTS IN THE PURIFICATION OF METALS, AND
ESPECIALLY IN THE MANUFACTURE OF CAST STEEL" A communication
from abroad by Henri Harmet, of St. Etienne, in the Republic of France.
-
of the Commissioners of Patents on the 1st December 1881.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN THE
PURIFICATION OF METALS AND ESPECIALLY IN THE MANUFACTURE OF CAST
STEEL' A communication from abroad by Henri Harinet of St. Etienno in the
Republic of France
"
This Invention has for its object improvements in the purification of metals and
especially in the manufacture of cast steel.
It consists in a new process characterised by the employment of apparatus such
as hereinafter described and represented in the annexed Drawing.
DESCRIPTION OF THE APPARATUS.
1. A is a vertical receiver into which are charged from the top at H in suitable
proportions the solid matters (metal and reagents) which have to be simultaneously
melted the fusion takes place at the lower part of this receiver.
2. B combustion and purifying chamber in which the heat is produced by n
burner supplied with either gas or oils whilst upon the inclined sole of the furnace
as the fusion of the metals and reagents takes place they run out together constant
change of the surfaces in contact resulting.
The length of this chamber and its inclination will vary in accordance with the
greater or less inflammability of the combustible employed and according to the
time which it is desired to give to the flow of the melted mixture and the reactions
which accompany.it
3. C. the crucible either fixed or movable which receives all the liquid matters
and at the bottom of which the metal concentrates after having slowly traversed
drop by drop the upper layer of purifying slag. A hole a allows all the metal to
run out from the crucible into a ladle in a furnace or any other suitable receiver.-
A hole allows the excess of slag to pass of.

page_text: 4. D.-entrance for the combustible gases or volatilised oils E. entrance for the
air blast
D and E together form a burner directing a jet upon the lower part of the
receiver A.
5. F entrance for the blast for heating the crucible C when necessary a jet of
air under low pressure is thrown into the crucible to agitate the contents and hasten
the reaction
In various places the sheet iron casing of the apparatus is pierced with holes to
permit the working of the apparatus to be observed and to effect repairs. The gas
and air inlets are regulated by slides.
The arrangement of this apparatus which avoids contact with solid fuel and
which furnishes all the hent necessary to the fusion and the chemical reactions
leaves the operator entirely free in the choice of raw materials and the composition
of the slag according to the results to be obtained it facilitates besides tho action
of the slag by prolonging its contact with the metal.
When it is required to purify cast iron or wrought iron or steel scrap the
operation is conducted somewhat as follows:-
All the apparatus being cold pieces of burning wood are thrown into the
crucible C and the gas is admitted by the opening D, the blast at F. The flame
produced strikes the bottom of the crucible and heats it and filling the whole of
the apparatus escapes by the upper chimney. The crucible becomes of a bright
red heat and the entrance of wind at F is shut off E is opened and the cast iron
and scrap is charged into the receiver A with the addition of purifying matters
such as lime alumina oxides of iron and of manganese fluoride of calcium &c.,
It is well that the charging should commence with a small quantity of purifying
materials which being first melted run into the crucible C.
When the crucible is full the metal is tapped out
receiver the operation continues without any pause.
then a carburetted metal but free for the most part from impurities other than
carbon
into a ladle or other
In the ladle there is
This is hard steel of which the refining should be continued in another
apparatus either in a furnace analogous to that of Martin Siemens or Pernot or
in puddling furnace.
The lining of the purifier and the additions made to the metallic charge vary
according to the result desired. If it is wished to dephosphorise the metal the
lining is of basic matters (dolomite lime inagnesia bauxite) as little silecious as
possible, the additions consist of non silecious oxides of iron and of divers matters
capable of serving as bases or to increase the fusibility of the slags (lime magnesia
alumina fluoride of calcium alkalies) if it be wished especially to desulphurise
then the lining is also basic but the additions should be less oxidising and richer
in fluoride of calcium or in lime. If it be desired simply to employ the apparatus
for fusion without caring about separation of sulphur or of phosphorus a silicious
lining may be employed
By varying also the proportions of air and gas blown in the action of the products
of combustion may be modified and rendered more or less oxidising
Having thus described the process and the apparatus which I propose to employ
I wish it to be understood that I do not limit inyself to the exact arrangements
indicated which may be varied the main object being to do away with the
contact of the solid fuel with the matters to be melted and to form a combustion
and purifying chamber with a feeding receiver and a crucible substantially as
described
This process is particularly advantageous for the treatment of cast iron and
steel which after fusion and purification can be poured liquid into other apparatus
where the refining may be completed.

page_text: 1. A is a vertical receiver into which are charged from the top at H in suitable
proportions the solid matters (metal and reagents) which have to be simultaneously
melted; the fusion takes place at the lower part of this receiver.
2. B combustion and purifying chamber in which the heat is produced by a
burner supplied with either gas or oils whilst upon the inclined sole of the furnace
as the fusion of the metals and reagents takes place they run out together, constant
change of the surfaces in contact resulting. The length of this chamber and its
inclination will vary in accordance with the greater or less inflammability of the
combustible employed and according to the time which it is desired to give to the
flow of the melted mixture and the reactions which accompany it.
3. C the crucible either fixed or movable which receives all the liquid matters
and at the bottom of which the metal concentrates after having slowly traversed
drop by drop the upper layer of purifying slag. A hole a, allows all the metal to
run out from the crucible into a ladle in a furnace or any other suitable receiver.
A hole b allows the excess of slag to pass off.
4. D entrance for the combustible gases or volatilised oils. E entrance for the
air blast. D and E together form a burner directing a jet upon the lower part of
the receiver A.
5. F entrance for the blast for heating the crucible C. When necessary a jet of
air under low pressure is thrown into the crucible to agitate the contents and
hasten the reaction. In various places the sheet iron casing of the apparatus is
pierced with holes to permit the working of the apparatus to be observed and to
effect repairs. The gas and air inlets are regulated by slides.
The arrangement of this apparatus which avoids contact with solid fuel and
which furnishes all the heat necessary to the fusion and the chemical reactions
leaves the operator entirely free in the choice of raw materials and the composition
of the slag according to the results to be obtained; it facilitates besides the action
of the slag by prolonging its contact with the metal.
When it is required to purify cast iron or wrought iron or steel scrap the
operation is conducted somewhat as follows:-
All the apparatus being cold pieces of burning wood are thrown into the
crucible C and the gas is admitted by the opening Ď; the blast at F. The flame
produced strikes the bottom of the crucible and heats it, and filling the whole of
the apparatus escapes by the upper chimney. The crucible becomes of a bright
red heat and the entrance of wind at F is shut off, E is opened and the cast iron
and scrap is charged into the receiver A with the addition of purifying matters
such as lime alumina oxides of iron and of manganese fluoride of calcium etc.

page_text: It is well that the charging should commence with a small quantity of purifying
materials which being first inclted run into the crucible C. When the crucible is
full the metal is tapped out into a ladlo or other receiver b, the operation continues
without any pause. In the ladle there is then a carburetted metal but free for the
most part from impurities other than carbon.
This is hard steel of which the refining should be continued in another
apparatus either in a furnace analogous to that of Martin, Siemens, or Pernot or
in a puddling furnace.
The lining of the purifier and the additions made to the metallic charge vary
according to the result desired. If it is wished to dephosphorize the metal the
lining is of basic matters (dolomite, lime, magnesia, bauxite) as little silicious as
possible; the additions consist of non-silicious oxides of iron and of divers matters
capable of serving as bases, or to increase the fusibility of the slags (lime,
magnesia, alumina fluoride of calcium alkalies) if it be wished especially to
desulphurise then the lining is also basic but the additions should be less oxidising
and richer in fluorido of calcium or in lime. If it be desired simply to employ the
apparatus for fusion without caring about separation of sulphur or of phosphorus a
silicious lining may be employed.
By varying also the proportions of air and gas blown in the action of the
products of combustion may be modified and rendered more or less oxidising.
Having thus described the process and the apparatus which I propose to employ
I wish it to be understood that I do not limit myself to the exact arrangements
indicated which may be varied the main object being to do away with the
contact of the solid fuel with the matters to be melted and to form a combustion
and purifying chamber with a feeding receiver and a crucible substantially as
described.
This process is particularly advantageous for the treatment of cast iron and steel
which after fusion and purification can be poured liquid into other apparatus where
the refining may be completed.
I claim improvements in the purification of metals and especially in the
manufacture of cast steel substantially as described
In witness whereof I the said Sydney Pitt have hereunto set my hand
and seal this Thirty first day of May in the year of our Lord One thousand
eight hundred and eighty two.