A NEW OR IMPROVED PROCESS OF PURIFYING METALS AND PARTICULARLY IRON AND STEEL
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M. &
W. Clark 53, Chancery Lane, in the County of Middlesex, Patent Agents,
for an Invention of A NEW OR IMPROVED PROCESS OF PURIFYING METALS
AND PARTICULARLY IRON AND STEEL Communicated to him from abroad by
Charles Edwards, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 13th July 1882.
ALEXANDER MELVILLE CLARK of the firm of A. M. &. W. Clark of
53 Chancery Lane in the County of Middlesex, Patent Agents
"A NEW OR
IMPROVED PROCESS OF PURIFYING METALS AND PARTICULARLY IRON AND STEEL
[Communicated to him from abroad by Charles Edwards, of Paris, France.]
This Invention consists in annealing metals (and more especially wrought, cast
and malleable iron, Bessemer, or other steel &c) in a current of hydrogen gas
produced in the ordinary way but purified by one or more washings in order to
extract from the said metals all the metalloids (such as sulphur, phosphorus,
arsenic, nitrogen, silicon, &c) which are by their nature prejudicial to the good
quality of the metal. The process of this Invention has moreover the effect of
causing a thorough diffusion of carbon throughout the mass of the metal as is now
the case in the manufacture of steel and malleable iron.
The mode of operation in carrying out this Invention is as follows:-The metals
to be treated are placed in cast iron or other retorts lined internally or having
incorporated in their mass a suitable varnish or enamel and hermetically closed by
means of luted covers. The gas enters the retort by a suitable opening and escapes
by another, these openings being provided for this purpose with metallic tubes.
The outlet tube is plunged into a liquid reagent, for instance a copper liquor which
has a three fold effect, vis-1st. Of preventing the entry of atmospheric air.
2nd. Of indicating by its appearance the extent to which the extraction of the
impurities from the metal by the hydrogen gas has been carried. 3rd. Of allowing
the gas pressure to be conveniently regulated in the apparatus. The retorts are

page_text: heated to a temperature of 600° or 700° C. and this heat is maintained during
the whole of the process, the duration of which varies according to the nature and
size of the pieces under treatment. The effect produced by the above described
operation is as follows:-
The hydrogen gas always carries off with it water in the form of vapor, which
vapor coming into contact with the particles of the metal, the above mentioned
temperature (600° or 700° C.) destroys the combinations of iron with the metalloids
(sulphur, phosphorus, silicon, arsenic, nitrogen, &c) which are thus extracted in
the form of gases in combination with hydrogen. On the other hand the excess of
hydrogen prevents the oxidation of the iron and reduces the rust particles often
found in pieces of steel and iron, and which prevent their perfect welding.
The hydrogen gas also acts upon the carbon, a portion of which is disengaged in
the form of hydrocarbon gas when the material under treatment is cast iron or
other material containing a high percentage of carbon, whilst the remaining portion
of carbon is left in the metal wherein it becomes diffused in a most uniform
manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Great Seal Patent Office on
the 13th January 1883.
ALEXANDER MELVILLE CLARK of the Firm of A, M, and W, Clark of
53 Chancery Lane in the County of Middlesex Patent Agents " A NEW OR
IMPROVED PROCESS OF PURIFYING METALS AND PARTICULARLY IRON AND STEEL.'
A communication to me from abroad by Charles Edwards of Paris, France.
"
This Invention consists in annealing metals (and more especially wrought, cast,
and malleable iron, Bessemer, or other steel, &c) in a current of, hydrogen gas
produced in the ordinary way, but purified by one or more washings in order to
extract from the said metals all the metalloids (such as sulphur, phosphorus,
arsenic, nitrogen, silicon, &c) which are by their nature prejudicial to the good
quality of the metal. The process of this Invention has moreover the effect of
causing a thorough diffusion of carbon throughout the mass of the metal as is now
the case in the manufacture of steel and malleable iron.
The mode of operation in carrying out this Invention is as follows:-The metals
to be treated are placed in cast iron or other retorts lined internally with, or
having incorporated in their mass, a suitable varnish or enamel and hermetically
closed by means of luted covers. The gas enters the retort by a suitable opening
and escapes by another, these openings being provided for this purpose with
metallic tubes. The outlet tube is plunged into a liquid reagent, for instance, a
copper liquor which has a three fold effect, viz-1st. Of preventing the entry of
atmospheric air; 2nd. Of indicating by its appearance the extent to which the
extraction of the impurities from the metal by the hydrogen gas has been carried;
3rd. Of allowing the gas pressure to be conveniently regulated in the apparatus.
The retorts are heated to a temperature of 600° or 700° C: and this heat is main-
tained during the whole of the process, the duration of which varies according to
the nature and size of the pieces under treatment. The effect produced by the
above described operation is as follows :-
The hydrogen gas always carries off with it water in the form of vapor, which
vapor coming into contact with the particles of the metal, the above mentioned
temperature (600° or 700° C.) destroys the combinations of iron with the metalloids
(sulphur, phosphorus, silicon, arsenic, nitrogen, &c) which are thus extracted in
the form of gases in combination with bydrogen. On the other hand the excess
of hydrogen prevents the oxidation of the iron and reduces the rust particles often
found in pieces of steel and iron and which prevent their perfect welding. The
hydrogen gas also acts upon the carbon, a portion of which is disengaged in the
form of hydrocarbon gas when the material under treatment is cast iron or other
material containing a high percentage of carbon, whilst the remaining portion of
carbon is left in the metal wherein it becomes diffused in a most uniform manner.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is.
The herein described method of treating metals especially wrought, cast, and
malleable iron and steel and which consists in annealing or heating the said metals
in an atmosphere of hydrogen gas (produced in any convenient way and purified by
one or more washings) substantially as and for the purposes herein specified.
In Witness whereof I the said Alexander Melville Clark have hereunto set
my hand and seal this thirteenth day of January, A.D. 1883.