Iм- PROVEMENTS IN THE PRODUCTION OF SULPHURIC AND HYDROCHLORIC ACIDS, of CARBONATES OF POTASH AND SODA, AND ALSO OF CHLORINE
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 "Iм-
PROVEMENTS IN THE PRODUCTION OF SULPHURIC AND HYDROCHLORIC ACIDS, of
CARBONATES OF POTASH AND SODA, AND ALSO OF CHLORINE."-A communi-
cation from abroad by Haydn Mozart Baker, of the City, County,
and State of New York United States of America
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 21st July 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 PRODUCTION OF SULPHURIC AND HYDRO-
CHLORIC ACIDS, OF CARBONATES OF POTASH AND SODA, AND ALSO OF CHLORINE," a
communication to me from abroad by Haydn Mozart Baker, of the City,.
County, and State of New York, United States of America, to be as
follows:-
The first part of this Invention relates to a new method of effecting:
the decomposition of alkaline or of alkaline earthy compounds, so as to

page_text: obtain new compounds of the bases and to utilise the chlorine previously
in combination, and consists in effecting the decomposition of the
alkaline or of the alkaline earthy chlorides by heating together or by
fusion with certain hydrates or hydrated compounds, such, for example,
as the hydrates of alumina, such being either the monohydrate, or the
bihydrate, or terhydrate of alumina, or other hydrated compounds which
part with their water at an elevated temperature, and then in effecting
the decomposition of the resulting aluminate, such, for example, as the
aluminate of soda or potash by solution in water and decomposition by
means of carbonic acid.
The second part of my Invention relates to the decomposition of
anhydrous hydrochloric acid in the presence of chloride of calcium by
the employment of sulphurous acid.
The third part of my Invention relates to the production of sulphuric
and hydrochloric acids by the decomposition of sulphurous acid in the
presence of water by means of chlorine.
In carrying out the first part of my Invention I proceed as follows:-
I mix the alkaline or alkaline earthy chloride with the hydrates of
alumina, and when the terhydrate is employed then in about the
proportion of 157 parts by weight of terhydrate of calcium to about
60 parts by weight of chloride of sodium, or with about 85 parts of
chloride of potassium; and when the mixture has been subjected to the
action of heat either in a retort or other suitable vessel, the resulting
aluminate is to be dissolved in water, and the soluble aluminate is
decomposed by means of carbonic acid, and the resulting solution of
carbonate of soda or carbonate of potash is separated by decantation or
otherwise, and the hydrated alumina may again be employed. The
solution of the alkaline carbonates may be evaporated and will then be
found to be in a commercial form, or they may be otherwise employed.
The hydrocloric acid resulting from the before-mentioned decomposition
is to be collected as is well understood.
In carrying out the second part of my Invention hydrochloric acid
obtained as before mentioned or from any other source is to be rendered
anhydrous by the employment of fused chloride of calcium or otherwise,
and when by preference in the presence of chloride of calcium contained;
in a chamber is to be decomposed by means of sulphurous acid, so that
sulphur chlorine and water result. The chlorine thus resulting may be
conducted from the chamber and be economised, as is well understood,

page_text: and the sulphur being separated from the chloride of calcium by the
solution of the chloride of calcium in water of the sulphur may be
employed either for the production of sulphurous acid or otherwise.
In carrying out the third part of my Invention I cause a solution of
chlorine in water to come in contact with sulphurous acid by preference
when contained in glass vessels and exposed to the action of light, so
that sulphuric and hydrochloric acids may be produced, which acids
may be separated by means of distillation, and when separated may be.
utilised.
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 21st January 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.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of July, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-fourth
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 PRODUCTION OF SULPHURIC AND HYDROCHLORIC ACIDS, OF CARBONATES OF
POTASH AND SODA, AND ALSO OF CHLORINE," a communication to me from.
abroad by Haydn Mozart Baker, of the City, County, and State of New
York, United States of America, upon the condition (amongst others).
that I, the said John Henry Johnson, my executers or administrators, 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 performed, and cause the same to be filed,

page_text: 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 the 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 main object of the Invention is to effect the decomposition of the
alkaline chlorides by the employment of "hydrates" which yield up
their water only at exalted temperatures, thereby supplying and applying
the said water in the nascent state.
The Invention also includes the decomposition of hydrochloric acid
in the anhydrous condition by the employment of anhydrous sulphurous
acid in the presence of chloride of calcium or other suitable dehydrating
agent.
The Invention furthermore embraces the employment of chlorine gas
and water as oxidizing agents for the purpose of transforming sulphurous'
acid into sulphuric acid. It has long been known that steam passed
over chlorides of sodium or potassium in a fused condition effected
mutual decomposition of the water and alkaline chlorides with the
formation of hydrochloric acid and caustic soda or potassa dependent
upon which chloride had been employed. It has also been thoroughly
ascertained that these reactions could not be made available for industrial
purposes on account of the volatility of the alkaline chlorides in the
presence of water or steam and the degree of velocity or force with
which the rapid transit of the steam conveyed away the unconverted
chloride to a locality where the temperature was too low to effect the
desired decomposition.
It may be further stated that were the transformations to occur
during the flight of the steam and chlorides the moment the compounds
so formed attained a low temperature they would react upon each
other and reproduce the compounds originally employed.
This Invention seeks to and does obviate these objections as it supplies
and applies water in the nascent state to alkaline chlorides at high
temperatures by the employment and use of "hydrates." The "hydrates"
which part with their water at high temperatures and are of moderate
cost are the hydrated oxides of potassium, sodium, barium, strontium,
calcium, magnesium, and aluminum. When oxides of sodium and

page_text: potassium are the agents used in the hydrated state for decomposing
alkaline chlorides, silicic acid should be used in conjunction with
them to expel their water and avoid the detrimental influence of the
caustic alkalies upon the apparatus. It is preferable to use hydrated
oxide of aluminum for the purpose of decomposing the alkaline chlorides
for the reason that it comports itself as an acid after having surrendered
its water, and may also act by catalysis before that time. Alumiña
exerts the influence of a base towards water, but in the presence of
alkalies at high temperatures its behaviour is that of an acid, its acid
properties increasing in ratio with the increase of temperature, but when
silica is present the basic properties increase under the same circum-
stances. There are three hydrates of alumina, the monohydrate (diaspore),
the bihydrate, and the terhydrate, known by some as "gibboite," by
others "hydrargillite." The terhydrate is also obtained by the preci-
pitation of alumina from its acid solutions with alkalies and carbonated
alkalies and also by precipitation from solutions of the aluminates by.
carbonic acid and the bicarbonates of potassa, soda, and ammonia.
The first stage or process of the Invention is as follows:- A mixture
of terhydrate of alumina and chloride of sodium is placed in a retort
which may be of any suitable material but is preferably of completely
vitrified clay. The retort is sealed and the temperature gradually
elevated and the heat continued until the chloride of sodium is thoroughly
decomposed, which may be known by observing when the evolution of
hydrochloric acid ceases. It is proper to cause the retort and its contents
to attain a full red heat, the complete decomposition of a given quantity.
of chloride of sodium however has been effected by the above process
in glass apparatus without at all affecting the internal vitreous surface
of the retort, shewing clearly that no silicates were formed, nor could
there be as the heat was obtained from a common gas flame, and the
exterior of the retort was entirely covered with unconsumed carbon
in the form of lampblack, showing that the transformations are effected
at a comparatively low temperature. It is well to employ sufficient
terhydrate of alumina to secure the complete decomposition of all the
alkaline chloride acted upon. The proportions may be varied, but
those found most suitable and convenient are 157 parts of the terhydrate
of alumina and 60 parts of chloride of sodium, and when chloride of
potassium is acted upon 160 parts of terhydrate of alumina, and 85
parts of chloride of potassium. When the alkaline chloride has been.

page_text: all decomposed there is left in the retort alluminate of soda while
hydrochloric acid has passed into a Woulfe or other condensing apparatus,
which may be of clay, glass, or other suitable material. The alluminate
of soda is now withdrawn from the retort, dissolved in water, and then
submitted to the action of carbonic acid which seizes the soda, forming
carbonate of soda in solution, and precipitates the alumina as a terhydrate
again. The carbonate of soda is then obtained ready for the market by
evaporating the solution in the usual manner. The alluminate of soda
may also be decomposed by adding one equivalent of hydrated bicarbonate
of soda in the dry state to each equivalent of aluminate of soda. The
same relations exist when alluminate of potassa is treated with bicarbonate
of potassa. The recovered terhydrate of alumina after washing is
prepared for service in decomposing new quantities of alkaline chlorides.
The anhydrous free alumina must be fused with carbonate of soda, and
precipitated again to make it have the composition of terhydrate of
alumina and of service in decomposing alkaline chlorides. The hydro-
chloric acid will be found to have been absorbed by the water in the
Woulfe apparatus and may be made of any density which the requirements
of the market demand or may be used for the production of "chlorine"
for the purpose of carrying out the second portion of the Invention,
which is the decomposition of an anhydrous hydrochloric acid in the
presence of chloride of calcium by the employment of anhydrous
sulphurous acid. When an alkaline chloride, as chloride of sodium, is
heated with two equivalents of terhydrate of alumina, considerable free
water is expelled from the mixture at first, but when the mixture attains
a higher temperature there comes over nearly anhydrous hydrochloric
acid which may be rendered completely anhydrous by passing it over
and through fused chloride of calcium, and may then be conducted to
a large chamber containing chloride of calcium so dispersed as to present
as extended a surface as possible. In this chamber the hydrochloric
acid is made to come into intimate contact with anhydrous sulphurous
acid which has also been passed over chloride of calcium. The two
acids at once decompose each other, with the formation of chlorine
water and sulphur, the object of the chloride of calcium in the chamber
is to absorb and retain the water as fast as formed, otherwise the water
would combine with the chlorine, and these two substances would
react upon the remaining undecomposed sulphurous acid, and produce
sulphuric and hydrochloric acids, making in all a very complicated
mixture. It requires two equivalents of hydrochloric acid to decompose

page_text: one of sulphurous acid completely. The precipitated sulphur is of
course mixed with the chloride of calcium, but as it is insoluble and
the calcium chloride is very soluble they may readily be separated
by solution, filtration, or decantation, or by sublimation as convenience
may suggest. The chloride of calcium solution must be evaporated
to dryness and fused when it is ready for use again, as a dehydrating
agent. The sulphur can be dried and again burned for the production
of sulphurous acid, or it may be used for other purposes, and the
succeeding quantities of sulphurous acid may be obtained by the com-
bustion of pyrites in the present well-known way, or in any other
manner.
Having now produced chlorine it may be forced by a jet of steam to
pass out of the chamber and over hydrate of lime to form oxychloride
of calcium. It may also be made to pass into water forming a hydrate
of chlorine which is serviceable in the next and last stage of this
process which is as follows:-Water saturated with chlorine gas when
brought into contact with sulphurous acid in glass vessels exposed to
strong light and a moderately elevated temperature produces sulphuric
and hydrochloric acids, the mixture of these two acids submitted to
distillation in glass apparatus gives sulphuric acid in the retort while
the hydrochloric acid distils out and passes to the condensers and may
then be reconverted into chlorine as herein-before described.
Extensive experiments have demonstrated that this Invention is of
great practical importance as a cheap method of obtaining alumina from
"gibbsite" (terhydrate of alumina) carbonate of soda from common
salt (chloride of sodium) carbonate of potassa from chloride of potassium
and hydrochloric acid, and its allied products from the said chlorides,
together with the formation of sulphuric acid, all of which products
can be procured in a much greater state of purity than by processes
heretofore practised.
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 consider
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 employment and use of monohydrate, bihydrate, or
terhydrate of alumina, or other hydrated substances which part with

page_text: their water at elevated temperatures for the purpose of decomposing
alkaline or earthy chlorides as herein-before described.
Second. The employment and use of anhydrous, hydrochloric, and
'sulphurous acids in the presence of chloride of calcium for the purpose
of decomposing the said anhydrous hydrochloric acid and anhydrous
'sulphurous acid to produce chlorine gas and sulphur as herein-before
described.
Third. The use and employment of chlorine gas in the presence of
water and sulphurous acid substantially as described to produce sulphuric
and hydrochloric acids.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, this Nineteenth day
of January One thousand eight hundred and seventy-one.
J. HENRY JOHNSON. (L.S.)