Year: 1888

page_text: Date of Application, 25th Apr., 1888
Complete Specification Left, 23rd Jan., 1889
Complete Specification Accepted, 23rd Feb, 1889
I, ROBERT EDWARD CHATFIELD, of Woodlands, Sewardstone, in the County of
Essex, Manufacturing Chemist, do hereby declare the nature of this invention to be
as follows:-
My invention relates to the manufacture of ammonia and its sesquicarbonate in
such a manner as to obtain the products in a very pure condition and at com-
paratively little cost.
For producing very puro ammonia I mix in a close vessel sulphate of ammonia or a
solution thereof, and inagnesia with an excess of water of solution, and I apply
heat gradually raising it to about 170° F. The sulphate of ammonia becomes decom-
posed, the ammonia passes off, and is condensed in aqueous solution.
The magnesia combining with the sulphuric acid becomes sulphate of magnesia
more or less in solution, which may be crystallised for the market as Epsom salts, or
may be reconverted into magnesia by any known process for that purpose. The
weaker ammonia that comes off last may be used as solvent in a subsequent operation.
For producing sesquicarbonate of ammonia I charge a close vessel with aqueous
solution of ammonia which, when great purity of product is required, is perferably
that produced as above described. Into the upper part of this vessel above the
ammonia solution I admit carbonic acid gas preferably taking care that at first there
should be only such an amount of gas admitted as will give about one equivalent
thereof to two equivalents of ammonia. The solution produced at this stage may now
be subjected to heat either in the same vessel or in another vessel an additional
supply of carbonic acid being furnished and sesquicarbonate of ammonia is thus
sublimed from it.
The carbonic acid employed may be obtained in any of the known ways, but I prefer
to obtain it by calcining magnesite in close vessels magnesia being thus produced
which I may use for the decomposition of sulphate of ammonia as above described.
Dated this 25th day of April 1888.
-
ABEL & IMRAY.
Agents for the Applicant.

page_text: Sesqui Carbonate.
I, ROBERT EDWARD CHATFIELD, of Woodlands, Sewardstone, in the County of Essex,
Manufacturing 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:-
My invention relates to the manufacture of ammonia and its sesqui carbonate in
such a manner as to obtain; the products in a very pure condition and at com-
paratively little cost.
For producing very pure ammonia I mix in a close vessel sulphate of ammonia or a
solution thereof, and magnesia, in excess along with a large excess of water of solution,
and I apply heat, gradually raising it to about 240° F.
The sulphate of ammonia becomes decomposed, the ammonia passes off, and is con-
densed in aqueous solution.
The magnesia combining with the sulphuric acid becomes sulphate of magnesia
more or less in solution, which may be crystallised for the market as Epsom
salts, or may be reconverted into magnesia by any known process for that purpose.
The weaker ammonia solution that comes off last may be used partly as solvent of the
sulphate of ammonia in a subsequent operation, and also instead of water to absorb the
ammonia subsequently evolved.
For producing sesqui carbonate of ammonia, I charge a close vessel with cold
aqueous solution of ammonia, which when great purity of product is required, is
preferably that produced as above described. Into the upper part of this vessel above
the ammonia solution, which is not externally heated, I admit carbonic acid gas,
preferably taking care that when a strong solution of ammonia is used at first there
should be only such an amount of gas admitted as will bring the solution to a strength
not exceeding 20° Beaumé. The solution produced at this stage may now be subjected
to heat either in the same vessel or in another vessel, an additional supply of carbonic
acid being admitted to the vessel and sesqui carbonate of ammonia is thus sublimed
from it and collected in suitable receptacles.
The carbonic acid employed may be obtained in any of the known ways, but I
prefer to obtain it by calcining magnesite in close vessels magnesia being thus
produced which I may use for the decomposition of sulphate of ammonia as above
described.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. The herein described process for manufacture of ammonia by decomposing

page_text: sulphate of ammonia by means of magnesia in excess, in presence of water in large
excess.
2. The herein described process for manufacture of sesqui carbonate of ammonia
by treating ammonia solution with carbonic acid without external heating until the
solution attains a strength not exceeding 20° Beaumé and then heating while
farther carbonic acid is furnished, and thereby subliming off sesquicarbonate of
ammonia.
T1000
ABEL & IMRAY,
Agents for the Applicant.