IMPROVEMENTS IN THE MANUFACTURE OF SALTS AND PREPARATIONS OF AMMONIA
Year: 1860

page_text: LETTERS PATENT to George Robinson, of the Town and County of the
Town of Newcastle-upon-Tyne, Doctor of Medicine, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF SALTS AND PREPARATIONS OF
AMMONIA."
Sealed the 23rd November 1860, and dated the 28th May 1860.
PROVISIONAL SPECIFICATION left by the said George Robinson at the
Office of the Commissioners of Patents, with his Petition, on the
28th May 1860.
I, GEORGE ROBINSON, of the Town and County of the Town of Newcastle-
upon-Tyne, Doctor of Medicine, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SALTS AND PREPARATIONS
OF AMMONIA," to be as follows:-
My improvements consist in forming carbonate of ammonia directly from
the sulphate of ammonia, by heating the latter to a certain point, so as to
disengage one half of the ammonia contained in it, and then causing the
ammonia thus set free to combine with carbonic acid gas. For this purpose
the sulphate of ammonia is to be subjected to a certain regulated heat, by
which it is converted into bisulphate of ammonia in consequence of the
volatilization of half of its ammonia, the heat being at the same time insuffi-
cient to drive off the sulphuric acid. A temperature of between 500° and
600° of Fahrenheit answers best, and may be ensured by the careful regulation
of a gas furnace, or by the use of an oil bath, the dead oil of coal tar furnishing
a cheap material, or by employing superheated steam. The gas or vapour of
ammonia as it is disengaged is brought into contact with carbonic acid gas
suitable passages and chambers, where the carbonic acid and ammonia
combine and condense into a solid crystalline deposit. The carbonic acid gas,
in

page_text: which may be obtained from any convenient source, should be in excess, and
hence the deposit will generally consist of sesqui-carbonate and bicarbonate of
ammonia; but in using the term carbonate of ammonia I wish to be understood
as including all the combinations of carbonic acid and ammonia which are
capable of being formed by this process.
The passages and chambers, which may be formed of lead or glazed bricks,
or other suitable material, and which are to be kept cool, should be filled with
carbonic acid gas before the evolution of ammonia commences, in order that
the whole of the latter may be neutralized and deposited.
The sulphate of ammonia during the application of the heat may be placed
in an iron or clay or stoneware retort or vessel, lined with lead, and the
termination of the process will be indicated when the vapours proceeding from
the heated sulphate of ammonia no longer manifest an alkaline action on
litmus or turmeric paper. The remaining bisulphate of ammonia on being
dissolved in water may be used instead of sulphuric acid to combine with and
fix fresh ammonia in the form of neutral sulphate. It will thus economise the
sulphuric acid in the ordinary process of obtaining sulphate of ammonia from
the ammoniacal liquor of gasworks, since by the alternate conversion of the
neutral sulphate into the bisulphate of ammonia, in the manner above
described, and the subsequent reconversion of the bisulphate into the sulphate
by dissolving the former and bringing it in contact with fresh ammonia, a
given quantity of sulphuric acid will serve for several processes. The solution
of the bisulphate of ammonia may also be employed in the manufacture of
alum by boiling it with spent alum shale, or other roasted clays.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Robinson in the Great Seal Patent Office on the
28th November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
ROBINSON, of the Town and County of the Town of Newcastle-upon-Tyne,
Doctor of Medicine, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of May, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Robinson, Her special licence that I, the said George
Robinson, my executors, administrators, and assigns, or such others as I, the
said George Robinson, my executors, administrators, and assigns, should at

page_text: 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 SALTS AND PREPARATIONS OF AMMONIA,"
upon the condition (amongst others) that I, the said George Robinson, my
executors or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, 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 George Robinson, 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 thereof, that is to say:-
For this purpose
regulated heat, by
My improvements consist in forming carbonate of ammonia directly from
the sulphate of ammonia by heating the latter to a certain point, so as to
disengage one half of the ammonia contained in it, and then causing the
ammonia thus set free to combine with carbonic acid gas.
the sulphate of ammonia is to be subjected to a certain
which it is converted into bisulphate of ammonia in consequence of the
volatilization of half of its ammonia, the heat being insufficient to drive off the
sulphuric acid. A temperature of between 500° and 600° of Fahrenheit
answers best, and may be insured by the careful regulation of a gas furnace or
by the use of an oil bath, the dead oil of coal tar furnishing a cheap material,
or by employing superheated steam. The gas or vapour of ammonia as it is
disengaged is brought into contact with carbonic acid gas in suitable passages
and chambers, where the carbonic acid and ammonia combine, and condense
into a solid crystalline deposit. The carbonic acid gas, which may be obtained
from any convenient source, should be in excess, and hence the deposit will
generally consist of sesqui-carbonate and bicarbonate of ammonia; but in
using the term carbonate of ammonia I wish it to be understood as including
all the combinations of carbonic acid and ammonia which are capable of being
formed by this process. The passages and chambers, which may be formed
of lead or glazed bricks, or other suitable material, and which are to be kept
cool, should be filled with carbonic acid gas before the evolution of ammonia
commences, in order that the whole of the latter may be neutralized and
deposited.

page_text: The sulphate of ammonia during the application of the heat may be placed
in an iron, earthenware, or stoneware retort or vessel, lined with lead, and the
termination of the process will be indicated when the vapours proceeding from
the heated sulphate of ammonia no longer manifest an alkaline action on
litmus or turmeric paper. The remaining bisulphate of ammonia on being
dissolved in water may be used instead of sulphuric acid to combine with and
fix fresh ammonia in the form of neutral sulphate. It will thus economise
the sulphuric acid in the ordinary process of obtaining sulphate of ammonia
from the ammoniacal liquor of gasworks, since by the alternate conversion of
the neutral sulphate into the bisulphate of ammonia, in the manner above
described, and the subsequent reconversion of the bisulphate into the sulphate
by dissolving the former and bringing it in contact with fresh ammonia, a
given quantity of sulphuric acid will serve for several processes. The solution
of the bisulphate of ammonia may also be employed in the manufacture of
alum by boiling it with spent alum shale, or other roasted clays.
The sulphate of ammonia may be heated either alone, or, if it is intended
to manufacture alum directly from it, it is previously to be mixed with pipe-
clay or other pure source or sources of alumina. I shall describe each of
these processes separately.
A. The sulphate of ammonia is to be heated to between 500° and 600° of
Fahrenheit, but not exceeding the latter temperature, in a suitable vessel or
furnace, it will then melt and give off the vapour of ammonia, which may be
purified by passing through a very small quantity of water, not sufficient to
absorb much of the ammonia, and is then to be conducted to a chamber or
series of passages, where it meets with carbonic acid gas, and is there
precipitated and condensed as sesqui-carbonate and bicarbonate of ammonia.
This is to be collected and removed from time to time, and care is to be taken
that the chambers or passages are kept cool and always contain an excess of
the carbonic acid gas, in order that the whole of the ammonia may be
precipitated.
The decomposition of the sulphate of ammonia by heat is not to be carried
beyond that point at which the evolution of ammonia ceases; nor must the
degree of heat applied be sufficient to decompose or drive over the sulphuric
acid contained in it, which will remain in the vessel or furnace, combined with
a portion of the ammonia as bisulphate or supersulphate. This latter may be
run off from time to time while in a liquid form, and either allowed to solidify
on exposure to the air, in which state it is most convenient for carriage, or it
may be at once dissolved in a small quantity of water and usefully employed
for the following purposes:-

page_text: 1. The acid solution may be used to form fresh sulphate of ammonia by
employing it instead of sulphuric acid to fix the vapours of ammonia derived
by processes well known from the ammoniacal liquor of gasworks.
2. It may be used to form alum by boiling with it roasted and pure clay.
3. It may be used instead of sulphate of ammonia to manufacture carbonate
of ammonia by mixing it with chalk in close vessels, and afterwards heating
the mixture, whereby the loss of ammonia occurring in the usual process will
be avoided. For this purpose it is desirable that the chalk be in excess, in
order to ensure a copious supply of carbonic acid gas.
B. Where it is intended to manufacture alum directly from the sulphate of
ammonia, the latter is to be mixed with nearly an equal quantity of pure clay,
both being powdered and intimately mixed. They are then to be exposed to
a temperature of 500° or 600° of Fahrenheit in a close vessel. The vapours
of ammonia evolved are to be purified and condensed by carbonic acid gas in
the manner previously described, and the residue, which is generally of a
brownish color, is then to be heated with boiling water; the solution, which
tastes strongly of alum, is to be allowed to settle for a short time, and then
run off while still hot into suitable vessels for the alum to crystallize. The
mother liquor when boiled down will yield additional crystals of alum, and the
residue when dried may be mixed with fresh clay and heated as before.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
1. The manufacture of carbonates of ammonia by heating sulphate of
ammonia, and bringing the vapour of ammonia thus evolved into contact with
carbonic acid gas, in the manner described.
2. The manufacture of alum from the sulphate of ammonia by mixing clay
with it, and heating them, producing at the same time carbonate of ammonia,
as herein described.
3. The use of the solution of the bisulphate or supersulphate of ammonia
in water, to fix fresh ammonia, and thereby form fresh sulphate of ammonia
instead of employing for that purpose additional sulphuric acid.
In witness whereof, I, the said George Robinson, have hereunto set my
hand and seal, this Twenty-seventh day of November, One thousand
eight hundred and sixty.
GEORGE ROBINSON.
(L.S.)