Im- PROVEMENTS IN THE MANUFACTURE OF ACIDS AND ALKALINE SALTS
Year: 1870

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of “Im-
PROVEMENTS IN THE MANUFACTURE OF ACIDS AND ALKALINE SALTS."-A
communication from abroad by Haydn Mozart Baker, of Williams-
burg, in the State of New York, United States of America.
Sealed the 4th April 1871, and dated the 31st October 1870.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson.
at the Office of the Commissioners of Patents, with his Petition,
on the 31st October 1870.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ACIDS AND ALKALINE
SALTS," a communication to me from abroad by Haydn Mozart Baker,
of Williamsburg, in the State of New York, United States of America,
to be as follows:-
This Invention consists, firstly, in the employment of anhydrous or
hydrated alumina, with or without silicic acid, mechanically mixed or

page_text: chemically combined together with fine coal or other carbonaceous
substances for the purpose of decomposing salt cake and sulphate of soda
or sulphate of potash for the production of aluminate of soda or aluminate
of potash and sulphurous acid. An ordinary reverberatory furnace is
brought to a full red heat, and is charged with a "batch" consisting of
terhydrate of alumina, salt cake, or dry sulphate of soda and fine anthra-
cite or bituminous coal, charcoal, or other carbonaceous substance, ten
parts of salt cake or soda sulphate, and one three-fourths parts of carbon
being used with each five parts of alumina. When the batch begins to
evolve sulphurous acid it should be stirred and turned over with suitable
iron tools so as to expose the entire surface of the mass to the current
of air which passes through the furnace without forming any chemical
combination with the products of combustion. On the completion of
this part of the process there will be a mixture of aluminate of soda and
free anhydrous alumina in the furnace, but by the addition of sufficient
carbonate of soda the free aluminate is converted into aluminate of soda.
The batch is now withdrawn and dissolved in water, and carbonic acid gas
is passed through the solution to precipitate the alumina, the clear solution
of carbonate of soda being decanted or otherwise separated from the
precipitated hydrate of alumina. On evaporating the said solution to
dryness the product will be commercial carbonate of soda. The pre-
cipitated hydrate of alumina may again be employed in conjunction with
coal, coke, sawdust, and the like, for the decomposition of more sulphate
of soda or salt cake in the further production of carbonate of soda.
Anhydrous and hydrated alumina in conjunction with carbon and
sulphate of potash may be similarly treated, whereupon aluminate of
potash is formed instead of aluminate of soda. The proportions in which
the materials are used may be varied from those given, although
experiments have demonstrated these proportions to be most practicable.
Common clay, which is a chemical compound of silicic acid and alumina,
may be used with alkaline sulphates and fine coal, as herein described for
alumina with sulphates and coal, so that a decomposition of the said
sulphates ensues with the formation of silicate and aluminate of soda
or potash and sulphurous acid. The advantages of this process are that
it provides a cheap and complete method of decomposing alkaline
sulphates and producing carbonate of soda and sulphurous acid.
The second part of this Invention consists in the employment of the said
hydrates of alumina in conjunction with nitrate of potash or nitrate of
soda for the purpose of producing nitric acid and aluminate of potash or

page_text: soda, the hydrates of alumina being used in the place of the sulphuric
acid now commonly employed with nitrate of soda or nitrate of potash
for the production of nitric acid. A retort is charged with a mixture of
nitrate of soda or nitate of potash, and of monohydrate, bihydrate,
terhydrate, or quintohydrate of alumina in the proportion of one chemical
equivalent of soda or potash to one chemical equivalent of alumina
hydrate. The retort after being charged is sealed and connected with a
suitable condensing apparatus, and heat is applied to gradually raise the
temperature to one thousand degrees Fahrenheit, at which it is main-
tained until the decomposition of the nitrate is complete. Nitric acid
and its chemical constituents pass with water to the condensers, where a
rearrangement of the compounds formed by the action of the heat upon
the nitrates takes place reproducing nitric acid, while the soda or potash
left in the retort from the said nitrates combines with the alumina,
forming aluminate of potash or aluminate of soda, depending upon
which nitrate had been employed. The aluminate of soda or potash is
withdrawn from the retort and the said retort charged again with a new
batch and the operation repeated. The aluminate of potash or soda
may be applied to any industrial use or may be decomposed by carbonic
acid for the production of carbonate of soda or potash, thereby recovering
the alumina as a hydrate to be used again in the decomposition of
succeeding quantities of nitrates. Anhydrous alumina will accomplish
the decomposition of nitrates as herein described with the formation of
aluminate of the alkali and the production of nitric acid, but it is
impossible to obtain more than sixty-five per cent. of the theoretic
quantity of nitric acid by its use, while by the use of the hydrates of
|alumina ninety-seven per cent. of the theoretic quantity of said nitric
acid may be obtained. The advantages of this process are that it
provides an economical method of manufacturing nitric acid and
aluminate of soda or aluminate of potash of a very superior quality.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 29th April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of October, in the year
of our Lord One thousand eight hundred and seventy, in the 34th
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators,
and assigns, or such others as I, the said John Henry Johnson, my
executors, administrators, or assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF ACIDS AND ALKALINE SALTS," a communication from
abroad by Haydn Mozart Baker, of Williamsburg, in the State of New
York, United States of America, upon the condition (amongst others)
that I, the said John Henry Johnson, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :—
The said Invention consists, firstly, in the employment of anhydrous
or hydrated alumina with or without silicic acid mechanically mixed or
chemically combined together with fine coal or other carbonaceous
substances for the purpose of decomposing salt cake and sulphate of
soda, or sulphate of potash, for the production of aluminate of soda or
aluminate of potash and sulphurous acid. An ordinary reverberatory
furnace is brought to a full red heat, and is charged with a "batch,"
consisting of terhydrate of alumina, salt cake, or dry sulphate of soda,
and fine authracite or bituminous coal, charcoal, or other carbonaceous
substance; ten parts of salt cake or soda sulphate, and one three-fourths
part of carbon being used with each five parts of alumina. When the
batch begins to evolve sulphurous acid it should be stirred and turned
over with suitable iron tools, so as to expose the entire surface of the

page_text: mass to the current of air which passes through the furnace without
forming any chemical combination with the products of combustion.
Small samples from the batch may be withdrawn from time to time to
determine when the decomposition of the salt cake or sulphate of soda
has been completed. During the first stage of the process certain
portions of the alkaline sulphate become converted into sulphide of
sodium, and if a sample of the batch be withdrawn at this stage it will
exhibit a greenish black color, but if the heat be continually applied and
the batch constantly stirred, this color will gradually pass through
various shades to a pure white, and when this occurs the process is
complete. The sulphurous acid evolved may be utilized for those
purposes to which it is adapted. On the completion of this part of the
process there will be a mixture of aluminate of soda and free anhydrous
alumina in the furnace, but by the addition of sufficient carbonate of
soda the free aluminate is converted into aluminate of soda. The batch
is now withdrawn and dissolved in water, and carbonic acid gas is passed
through the solution to precipitate the alumina, the clear solution of
carbonate of soda being decanted or otherwise separated from the
precipitated hydrate of alumina. On evaporating the said solution to
dryness the product will be commercial carbonate of soda. The pre-
cipitated hydrate of alumina may again be employed in conjunction with
coal, coke, sawdust, and the like for the decomposition of more sulphate
of soda or salt cake in the further production of carbonate of soda. The
action of anhydrous and hydrated alumina in conjunction with carbon
and sulphate of potash corresponds with its action when used with
sulphate of soda, as herein-before described, except that aluminate of
potash is formed in this case instead of aluminate of soda. Anhydrous
alumina and coal together with sulphate of soda or sulphate of potash
act less perfectly and less rapidly than the hydrates of alumina. The
proportions in which the materials are used may be varied from those
given, although experiments have demonstrated these proportions to be
most practicable. Common clay, which is a chemical compound of
silicic acid and alumina, may be used with alkaline sulphates and fine
coal, as herein described, for alumina with sulphates and coal, so that a
decomposition of the said sulphates ensues with the formation of silicate
and aluminate of soda or potash and sulphurous acid. From this it will.
be seen that the relations of alumina with alkaline salts and other
substances have been anticipated. The advantages of this process are

page_text: that it provides a cheap and complete method of decomposing alkaline
sulphates and producing carbonate of soda and sulphurous acid.
The second part of this Invention consists in the employment of the
said hydrates of alumina in conjunction with nitrate of potash or nitrate
of soda for the purpose of producing nitric acid and aluminate of potash
or soda, the hydrates of alumina being used in the place of the sulphuric
acid now commonly employed with nitrate of soda or nitrate of potash
for the production of nitric acid. The object of employing the hydrates
of alumina is to furnish water to the nitric acid and its constituents as
they are liberated by the heat from the nitrates, and also to furnish a
substance which will act the part of an acid towards the alkali left by
the decomposition of the said nitrates, alumina in the presence of potash
and soda behaving as an acid. A retort is charged with a mixture of
nitrate of soda or nitrate of potash and of monohydrate, bihydrate,
terhydrate, or quintohydrate of alumina, in the proportion of one
chemical equivalent of soda or potash to one chemical equivalent of
alumina hydrate.
The most appropriate retorts are those of English manufacture, as
they will endure the expansion and contraction incident to the process
better than any others. The retort after being charged is sealed and
connected with a suitable condensing apparatus, and heat is applied to
gradually raise the temperature to 1000° Fahrenheit, at which it is
maintained until the decomposition of the nitrate is complete. Nitric
acid and its chemical constituents pass with water to the condensers,
where a rearrangement of the compounds formed by the action of the
heat upon the nitrates takes place, reproducing nitric acid, while the
soda or potash left in the retort from the said nitrates combines with the
alumina forming aluminate of potash or aluminate of soda, depending
upon which of the nitrates had been employed. The aluminate of soda
or potash is withdrawn from the retort, and the said rétort charged again
with a new batch, and the operation repeated. The aluminate of potash
or soda may be applied to any industrial use, or may be decomposed by
carbonic acid for the production of carbonate of soda or potash, thereby
recovering the alumina as a hydrate to be used again in the decom-
position of succeeding quantities of nitrates. Anhydrous alumina will
accomplish the decomposition of nitrates as herein described with the
formation of aluminate of the alkali and the production of nitric acid,
.

page_text: but it is impossible to obtain more than sixty-five per cent. of the
theoretic quantity of nitric acid by its use, whilst by the use of the
hydrates of alumina ninety-seven per cent. of the theoretic quantity of
said nitric acid may be obtained.
The great advantage of this process is that it provides an economical
method of manufacturing nitric acid and aluminate of soda or aluminate
of potash of a very superior quality.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I con-
sider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,―
First. The process of decomposing alkaline sulphates by the use
of alumina and carbonaceous matter, substantially as herein-before
described.
Second. The process of producing aluminates of potash and soda by
the use of anhydrous and hydrated alumina as herein set forth.
Third. The manufacture of nitric acid by the use of nitrates of potash
or soda and anhydrous or hydrated alumina, substantially as specified.
Fourth. The production of sulphurous acid by the process substantially
as herein described.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Twenty-eighth day of
April One thousand eight hundred and seventy-one.