Improvements in the Process of Obtaining Alloys of Aluminum with Copper and with other Metals.
Year: 1886

page_text: Improvements in the Process of Obtaining Alloys of Aluminum
with Copper and with other Metals.
•
I, JOHN CLARK of 80 Great Brook Street Birmingham in the County of Warwick,
Chemist, do hereby declare the nature of this invention to be as follows:-
The object of the first stage of my process is to produce a hydrated chloride of
aluminum Al C, OH, by treating alumina with nitro-hydrochloric acid, or with
commercial hydrochloric acid, or with gaseous hydrochloric acid as produced in soda
furnaces.
The second and principal stage of the process consists in mixing the hydrated
chloride of aluminum so produced, or the hydrated chloride of aluminum produced
by any known process, with certain re-agents which will decompose the hydrated
chloride of aluminum by combining with the chlorine and forming volatizable chlorides.
and then submitting the resulting mass, in the presence of the metal or metals to be
alloyed, to a melting heat whereby the volatile chlorides will be driven off and the
reduced aluminum will be alloyed directly with the said metal or metals. The desired
alloy is thus produced by a more direct and economical process than heretoforc.
For the purposes of my Invention, I operate on alumina as it is found in the several
kinds of clay, kaolin, bauxite, cryolite, or other natural source of alumina; also on
alumina when derived from these natural sources, or from alum.
In carrying my Invention into practice I shall first describe my process as applied
to common brown clay, remarking that the other materials may also be treated in a
similar manner.
When parts are stated parts by weight are understood.
I take of common brown clay, which may be used damp as dug from the earth or
be dried and ground to powder, eight parts and intimately mix it with sufficient
commercial nitro-hydrochloric acid(commonly called "aqua regia ") to the consistence
of a thin paste. I then let it stand in earthenware pans for about ten hours to mature,
during which time the acid displaces the silica and the chlorine of the acid unites with
the alumina converting it into the hydrated chloride of aluminum Al Ch. Off. the
clay at the same time loses its plastic character, gets short, rotten and slightly red in
color. For a similar purpose commercial hydrochloric acid may be used to effect the
decomposition described. but it takes a longer time to do so. In either case the acid
may be used cold, or be moderately heated.

page_text: Instead of manufacturing a hydrated chloride of aluminum as above describetl, I
may take the anhydrous chloride of aluminum produced by any known means, and
convert it into a hydrate by adding water to it. In either case, I then intimately mix
with the mass of hydrated chloride of aluminum a re-agent to take up the chlorine.
This re-agent consists of two and a half parts of zinc, which may be granulated and
reduced to powder, and one part of iron filings, or iron turnings and borings reduced
to powder may be used. Or, these metals as re-agents may be used separately and the
relative quantities increased proportionately. Or, the impure alloy of zinc and iron
known as spelter dross may be ground and used instead.
"
"
On adding the re-agent to the prepared clay the mass froths up considerably and
gets very hot. I let it stand to mature for about twenty four hours, and then dry it in
shallow pans or trays. The mass when dry is a light orange colored powder. I then
grind it with borax or other suitable flux and place it, together with about twenty
parts of copper (which I prefer to be in small pieces and mixed with the prepared
powder) in a crucible and melt them in an ordinary brass-founder's or other suitable
furnace. In about an hour the added zinc and iron will have volatilized as chlorides
and the aluminum will be found to be alloyed with the copper at the bottom of the
crucible and may be run into moulds or otherwise used as may be required.
Although I prefer to use commercial nitro hydrochloric and hydrochloric acids as
described because they are readily procured, I also use the gaseous hydro-chloric acid
as it escapes from the soda furnaces in which it is usually produced or otherwise, when
it is more convenient to do so. In using it in this way, I moisten with water the clay
or other material to be acted on, or I pass in a jet of steam with the gaseons
hydrochloric acid, and in this manner treat it in a separate chamber adjoining the soda-
furnace. I may also use ammonia or its carbonate, as a re-agent in combination with
the zinc and iron previously described, or by itself, in which latter case the salt sal-
ammoniac N H, Cl is formed instead of the chlorides of those metals, and like them is
also volatilized in the furnace when the metal to be alloyed is melted. I also use
quicklime for the same purpose.
The most usual alloy of aluminum is with copper as described, to which it imparts a
rich golden color and improves its qualities otherwise, but prepared as above described
it also alloys well with copper to which a small portion of tin or phosphorus or brass
has been added, also with silver and with German-silver to form white alloys.
Alumina, when treated in the manner described, imparts to white alloys, in general,
brilliancyandhardness-it can, therefore, be alloyedwith advantagewith the variouswell
known mixtures or alloys of Tin, Bismuth, Nickel Antimony, and Zinc used in the
several branches of trade and which will readily occur to the practical metallurgist.
When the metal to be treated or alloyed is in large quantities, it may be melted on
the hearth of a reverberatory furnace and the prepared chloride powder be stirred in
or mixed through it in any convenient manner. In the same way, when copper has
been smelted and purified in the ordinary course of reduction in a reverberatory
furnace, the prepared chloride of aluminum powder may then be stirred in or mixed
in any convenient manner with the melted metal which will then become alloyed with
aluminum by one direct operation, similar to that produced on a small scale in the
crucible above described.
I desire it to be understood that I do not restrict myself to the precise quantities of
the metal or other materials stated, because in alloying metals it is well known that
they do not follow a definite chemical combination but are rather mixtures of the
metals operated on; the quantities of each may therefore be varied to some extent
without departing from the main characteristics of this Invention.
J. CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Process of Obtaining Alloys of Aluminum
with Copper and with other Metals.
1, JOHN CLARK of 80 Great Brook Street Birmingham in the County of Warwick;
Chemist, 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:
The object of this Invention is to produce an alloy of aluminum with copper and
with certain other metals hereinafter specified; without obtaining metallic aluminum
by a separate and previous process, thereby producing such alloys by a direct and
more economical process than heretofore. For this purpose, I treat clays and other
sources of alumina afterwards specified by certain chemical acids and subsequently by
certain chemical re-agents hereinafter referred to in detail, whereby the aluminuni, in
whole or part, in such clays or other source of alumina, is alloyed with the copper or
other metals intended to be alloyed with aluminum, by the direct act of melting
such metals in presence of the aluminum powder prepared according to this
Invention.
The object of the first stage of my process is to produce a hydrated chloride of
aluminum Al C OH, by treating alumina with nitro-hydrochloric acid, or with
commercial hydrochloric acid, or with gaseous hydrochloric acid as produced in soda
furnaces or otherwise.
The second, and principal, stage of the process consists in mixing the hydrated
chloride of aluminum produced by the above, or by any known process, with certain
reagents which have a stronger affinity for chlorine than aluminum and which
decompose, in whole or part, the hydrated chloride of aluminum by combining with
the chlorine and forming chlorides, and submitting the resulting mass in the presence
of the metal or metals to be alloyed to a melting heat, whereby the chlorides formed
by such reagents will be volatilized and the aluminum will be caused in whole or part
to become alloyed directly with the said metal or metals in the act of melting them,
without the aluminum being obtained in the metallic state as a separate product. The
desired alloy is thus produced by a more direct and economical process than
heretofore.
For the purposes of my Invention. I operate on the silicate of alumina as it is found
in the several kinds of clay, kaolin, bauxite, or other natural source of alumina : also
on alumina when derived from these natural sources or from alum; or on the fluoride
of aluminum as in cryolite; which materials may be used separately or be mixed
together, as may be required.
In carrying my Invention into practice. I shall first describe my process as applied
to common brown clay, remarking that the other materials may also be treated in a
similar manner. When parts are stated, parts by weight are understood.
I take of common brown clay which may be used damp as dug from the earth, or
be dried and ground to powder. eight parts, and mix it with four parts (more or less)

page_text: of the oxide or hydrated oxide of aluminum and intimately mix therewith, sufficient
commercial nitro-hydrochloric acid (commonly called "Aqua Regia") to bring the
mixture to the consistence of a thin paste. I then let the mixture stand in carthenware
pans to mature, whereby the acid displaces the silica, and the chlorine of the acid
unites, in whole or part, with the alumina, converting it, or part of it, into the hydrated
chloride of aluminum Al Cl, OH,; the clay at the same time loses its plastic character,
gets short, rotten, and slightly red in color. For a similar purpose, commercial
hydrochloric acid may be used to effect the decomposition described, but it takes
longer to do so. In either case, the aciti used may be used cold or be moderately
heated.
it
Instead of manufacturing a hydrated chloride of aluminum, as above described, I
may take the anhydrous chloride of aluminum produced by any known means. and
convert it into a hydrate by adding water to it. In either case, I then intimately
mix with the mass of hydrated chloride of aluminum, a reagent to take up the chlorine.
This reagent consists, preferably, of three and a half parts of zinc which may be
granulated and reduced to powder, and one part of iron filings or iron turnings and
borings reduced to powder may be used. Or, these metals may be used separately
and the relative quantities increased proportionately. Or, the impure alloy of zinc and
iron known as spelter dross" may be granulated and used instead. On adding the
re-agent to the prepared clay, the mass froths up considerably and gets very hot. I
let it stand to mature for about four days or more, and then dry it in shallow pans or
trays. The mass when dry is a light brown colored powder. I then grind it with
borax or other suitable flux, and place it, together with about twenty parts of copper,
(which I prefer to be in small pieces and mixed with the prepared powder) in a crucible
and melt them in an ordinary brass founders' or other suitable furnace. In about an
hour, the added zinc and iron will have volatilized as chlorides and the aluminum in
whole or part will be found to be alloyed with the copper at the bottom of the crucible,
and may be run into moulds, or otherwise used, as may be required. I also use fluor-
spar as a flux, which I prefer to mix with the clay or other source of alumina, before
treating the same with the nitro-hydrochloric or other acid, as previously described in
the first stage of my process.
Although I prefer to use commercial nitro-hydrochloric and hydrochloric acids, as
described, because they are readily procured, I also use the gaseous hydrochloric acid
as it escapes from the soda furnaces in which it is usually produced, or otherwise, when
it is more convenient to do so. In using it in this way, I moisten with water. the clay
or other material to be acted on; or, I pass in a jet of stream with the gaseous hydro-
chloric acid, and in the manner described, treat such clay in a separate chamber
adjoining the soda furnace.
Although I prefer to use zinc and iron for re-agents, I may also use as re-agents for
the same purpose ammonia, either in the gaseous state N H or in solution as
commercial liquid ammonia of specific gravity 880, or as the sesqui-carbonate of
ammonia, or as bicarbonate of ammonia CO₂ (NH) H in which case the volatile salt
sal-ammoniac N H, Cl, is formed instead of the chlorides of those metals. I also uso
the following, partly as a flux and partly as a re-agent, quicklime Ca O (which I prefer
to use in the caustic state)or its carbonate,also potash or its carbonate or bi-carbonate,
also soda or its carbonate or bi-carbonate, whereby, in either case, the result of
decomposing, in whole or part, the hydrated chloride of aluminum is effected and when
the aluminum powder, so prepared is submitted to a melting heat in presence of the
copper, or other metals intended to be alloyed, aluminum is alloyed therewith by
the direct act of melting such metals, as previously described.
The most usual alloy aluminum is with copper, as described, to which it imparts
a rich golden color and improves itsqualities otherwise,but prepared as abovedescribed
it also alloys well with copper to which a proportion of tin or phosphorus, or sodium.
or zinc, or brass has been added; also with silver and with German silver to forni
white-alloys. By the process of this Invention, brilliancy and hardness are imparted
to white metal alloys in general. The process can, therefore, be applied with the
various well known mixtures or alloys of tin, bismuth, nickel, antimony, and zinc

page_text: (whether the same do or do not contain copper) used in the several branches of trade
and which will readily occur to the practical metallurgist.
When the metal to be treated or alloyed is in large quantities, it may be melted on
the hearth of a reverberatory or other furnace and the prepared aluminum powder
stirred in or mixed through it in any convenient manner. In the same way, when
copper has been smelted and purified in the ordinary course of reduction in a
reverberatory furnace, the prepared aluminum powder may then be stirred in or mixed
in any convenient manner with the melted metal which will then become alloyed with
aluminum by one direct operation similar to that produced on a small scale in the
crucible above described.
I desire it to be understood that I do not restrict myself to the precise quantities
of the metal or other materials stated, because in alloying metals it is well known that
they do not follow a definite chemical combination, but are rather mixtures of the
metals operated on; the quantities of each may, therefore, be varied to some extent
without departing from the main characteristics of this Invention.
Having now particularly described and ascertained the nature of the said Invention,
and in what manner the same is to be performed, I declare that what I claim is:
1st. The method of treating the silicate of alumina (as it is found in the several
kinds of clay, kaolin, bauxite, or other natural source of alumina), also alumina when
derived by any known means from these natural sources, or from alum, also the fluoride
of aluminum as in cryolite, with nitro-hydro-chloric acid or with hydrochloric acid in
the liquid or gaseous state, so as to obtain thereby a hydrated chloride of aluminum
as the preparatory or first stage of my process of alloying aluminum with copper and
with other metals, as herein specified.
2nd. The herein described method of alloying aluminum with copper and with
certain other metals, which consists in treating the hydrated chloride of aluminum
(prepared as above described, or obtained by any other known means) with re-agents
having a stronger affinity for chlorine than aluminum, mixing the resulting mass with
the metal or metals to be alloyed with aluminum and submitting the whole to a
melting heat in a crucible or other suitable furnace whereby the chlorides formed are
volatilized and the aluminum or part of it, is alloyed at one direct operation with the
copper or other metals without the aluminum being obtained as a separate product.
3rd. In the herein described process of alloying aluminum with copper and with
other metals, the employment of zinc, iron, "spelter dross" ammonia or its sesqui-
carbonate or bi-carbonate, as reducing agents for the hydrated chloride of aluminum
and the employment (partly as reducing agents and partly as a flux) of lime or its
carbonate also potash and soda or their carbonates or bi-carbonates, either separately
or together, substantially as and for the purpose herein specified.