Acid and in the Apparatus Employed therein.
Year: 1887

page_text: Date of Application, 15th Oct., 1887
Complete Specification Left, 10th July, 1888
Complete Specification Accepted, 10th Aug., 1888
Acid and in the Apparatus Employed therein.
I FREDERICK BALE of Coventry Hospital Droitwich Worcestershire Schoolmaster
do hereby declare the nature of the said invention for "IMPROVEMENTS IN THE
MANUFACTURE AND PRODUCTION OF AMMONIA AND HYDRO-CHLORIC ACID AND IN
THE APPARATUS EMPLOYED THEREIN "to be as follows:-
In the Soda-Ammonia process, now extensively employed for the production of
Bicarbonate of Soda from brine, the whole of the Chlorine is lost, being combined
with calcium forming therewith Chloride of calcium which has little or no
commercial value.
My present invention enables the Hydro Chloric Acid to be recovered, and further
substitutes a large saving in the manufacture of Ammonia, at a sight expense of
labour and fuel.
I am aware of recent improvements in this direction, but the principle of the
Volatilization of the Ammonic Chloride, and the passing of its vapour over heated
oxide, on which they are carried out, entails loss of Ammonia: Indeed it is
impossible to volatilize the Ammonic Chloride, without some loss of Ammonia, a
portion of which is decomposed into nitrogen and Hydrogen, and besides this con-
siderable difficulty arises in expelling all the Ammonia, from the retort in the first
operation, from the porous nature of the oxide used, when made into balls or bricks
for this process.
My process differs from this, in being essentially the "method of mixtures" of
oxide or oxides, and Ammonic Chloride. In this process I use trimanganic tetroxide,
obtained from any source, or magnesia, or a mixture of these in proper proportions,
and with these I mix solid Ammonic Chloride in the cold and dry way. I heat this
mixture in an ordinary Stourbridge fireclay retort, or other suitable furnace, at a low
temperature at first, when 1 find that the Ammonia is given off in quantity as if
lime were used.
When all the Ammonia is evolved the residue (which for the purpose of this
invention I call Residue No. 1) is a mixture of the oxide, or oxides of Manganese
and Magnesia (when such is used) together with the Chloride or oxy-Chloride of

page_text: Manganese or Magnesia or other metal, when such is used. When the evolution of
the Ammonia has ceased, there is a distinct pause in the reaction. When this stage
is reached, the residue may be heated, for some time. And then steam at a suitable
temperature is passed over the residue, when Hydro-Chloric Acid is evolved, and the
evolution of the Hydro-Chloric Acid goes on till the Chloride, or oxy-Chloride is
decomposed, a Residue being left (which I call Residue No. 2) which is practically
equivalent, to that with which we started, and will give the full equivalent of Ammonia,
when heated with Ammonic Chloride as at first, and from this point the round of
operations goes on continually.
Besides the oxides above named or their mixtures, other heavy oxides and oxides
of alkaline earths, may be used with advantage. I however prefer these oxides, or
mixtures of oxides, which are not volatile at the temperature employed, and whose
chlorides, are not volatile at this temperature, and for this purpose I have found that
trimanganic tetroxide alone, or mixed with magnesic oxide, and cobalt-oxide alone, or
mixed with magnesic oxide, or Nickel oxide alone, or mixed with magnesic oxide or
a mixture of all these oxides, are among the best in giving the full equivalent of
Ammonia, and in the ease, and low temperature at which they part with the Hydro-
Chloric Acid. The Apparatus I would use, is the same as that described in my
application No. 14,001 of Oct. 15th 1887 for "Improvements in the manufacture of
Ammonia and Chlorine and in the apparatus employed therein." The mixture of
oxide, or oxides, and Ammonic Chloride, should be kept in close contact at one end
of the retort, which may be about three parts full, till all the Ammonia was evolved,
then Residue 1 should be spread over the retort, to present as large a surface as possible,
to the oxidizing action of the steam. It would be well for it to be stirred at times by
mechanical means or otherwise.
Dated this 13th day of October 1887.

page_text: mрrоvешение 1 CHO
шацшасито
Acid and in the Apparatus Employed therein.
I, FREDERICK BALE of Coventry Hospital Droitwich, Worcestershire Schoolmaster
do hereby declare the nature of the said invention for "IMPROVEMENTS IN THE
MANUFACTURE OF AMMONIA AND HYDROCHLORIC ACID, AND IN THE APPARATUS
EMPLOYED THEREIN "and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
If Ammonia Chloride be volatilized and its vapour passed over or through heated
metallic oxide at a temperature of about 400° C or higher, the Ammonia which is
evolved is partially decomposed in its passage over the heated oxide, and this to the
extent of from 25 to 50 per cent. of the Aminonia evolved.
If however the Ammonium Chloride be intimately mixed in powder with metallic
oxide in powder as the oxide of Manganese (which I prefer), and the mixture then
gradually heated, the Ammonia is gradually and completely evolved at a temperature
of 130° C to about 325° C, without the loss mentioned above, by the Method of
Volatilization of the Ammonic Chloride. Most of the Ammonia is here evolved
between 130° C and 200° C.
In this "Method of mixtures" if the temperature of the Residue left after the
evolution of the Ammonia be kept below 350° Cand cold, and dry air, be passed over it,
no Chlorine is evolved at this temperature, but the residual Ammonia, and any little
undecomposed Ammonic Chloride, may be completely driven out of the retort, on
stirring the mixture.
In this method of mixtures if dry, and cold air be passed through the retort, from
the commencement of charging the retort, and throughout the operation for the
Ammonia (the temperature during the evolution of Ammonia being kept below 350° C),
so that the Ammonia may be removed from the retort as soon as formed, any loss by
leakage, and decomposition, is thus reduced to a minimum, and the Ammonia may be
obtained without loss.
If the Ammonic Chloride be mixed with nickel oxide instead of oxide of Manganese,
and heated, the Ammonia begins to bo freely given off at a temperature of about 325° (
and after on the passage of steam the Hydrochloric Acid at about 400° C. The
temperature varies with the oxide used. In the method of mixtures if the
Residue left (Residue No. 1) after the Ammonia has been evolved be maintained at a
temperature of about 325° C or lower, and dry air or oxygen be passed over it, or no
Chlorine is evolved at this temperature. If steam be now passed through the retort
Hydrochloric-Acid is freely evolved at this temperature, when Manganese is the
oxide used. Other oxides require a much higher temperature for, the evolution of the
Hydro-chloric-Acid.
With some few exceptions the metallic oxides having the composition, M. O,
MO, & MO, give the equivalent of Ammonia when heated with Ammonic Chloride
in mixtures, and as described: while oxides or sesquioxides of the composition M, O₂
yield about one third less Ammonia, the other third being decomposed into Nitrogen
and Hydrogen.
I carry out my invention based on these facts and discoveries in the following manner:―
In the soda Ammonia process now extensively employed for the production of

page_text: Bicarbonate of soda from brine the whole of the Chlorine is lost being combined
with Calcium forming therewith Chloride of Calciumn, which has little or no
commercial value.
My present invention enables the Chlorine to be recovered, as Hydro-chloric-Acid,
and further substitutes a large saving in the manufacture of Ammonia, at a slight
expense of labour and fuel."
I am aware of recent improvements in this direction, but the principle of the
Volatilization of the Ammonic Chloride, and the passing its vapour over heated and
fixed oxide, on which they are carried out, entails loss of Ammonia and other dis-
advantages; and besides this considerable difficulty arises in expelling all the Aminonia
from the retort, in the first operation, from the porous nature, and fixed character of
the oxides used, when made into balls or bricks for this process.
My process differs from this in being essentially the "Method of mixtures" of
oxide or oxides and Ammonic Chloride.
It differs also chiefly in the moveable
character of the oxide or oxides used, the low temperature employed, whereby the
Ammonia is saved; the use of peroxides for the full evolution of the Ammonia, at
the low temperature employed, the use of atmospheric air for the expulsion of the
Aminonia from the retort at the low temperature used, and in other ways. These
differences give great advantages:
In this process I use trimanganic tetroxide, obtained from any source, or any other
oxide of Manganese not sesquioxide, or magnesia, both preferably in powder, or a
mixture of these in intimate and proper proportions, and with this I mix solid
Ammonic Chloride, preferably in powder, in the cold and dry way at first. I heat
this mixture in an ordinary Stourbridge fire-clay retort, or other suitable furnace or
retort, at a low temperature at first; viz., from 130° C to 325° C. The temperature
depends on the oxide or oxides used. When trimanganic tetroxide is used which 1
prefer, the Ammonia begins to be evolved at about 130° C to 200° C. At the latter
temperature most of the Ammonia is evolved, and if the mixture be slowly heated
up to 325° C the evolution of the Ammonia is regular and complete at this
temperatures.
When all the Ammonia is given off, the Residue (which for the purpose of this
invention I call Residue number one) is a mixture of the oxide or oxides of
manganese, or magnesium (when such is used) together with the Chloride or oxy
Chloride, of manganese or magnesium or other metal, when such is used. When the
evolution of the Ammonia has ceased, there is a distinct pause in the reaction. When
this stage is reached, the residue may be heated for some time at a temperature below
350° C (or about 325° C) at the same time passing a dry neutral gas, or preferably
dry air, over the residue, which at the same time should be stirred, in order to expel
any residual Ammonia remaining in the retort, and any little undecomposed Ammonic
Chloride, which is thus easily and completely effected. Then the valves in the
conduits leading to the absorbing apparatus are shut, and those in the conduits
leading to the condensing Chambers are opened. Then steam at a suitable
temperature is passed over the residue, and immediately Hydro-chloric Acid i
evolved. This evolution of the Hydro-Chloric-Acid goes on, till the Chloride or
oxy Chloride is decomposed, a residue being left (which I call Residue No. 2)
which is practically equivalent to the oxide with which we started, and will give the
equivalent of Ammonia as at first when heated with Ammonic Chloride, and from
this point the round of operations goes on continually. It would be necessary for
Residue two to be taken from the retort at about intervals of a week, and washed
from common salt, when the latter is present with Ammonic Chloride. When this is
done, the retort would be next charged in the cold, by a mixture of oxide, or oxides,
and Ammonic Chloride, as at first. When charged in general without removal of
oxide, the Ammonic Chloride would be thrown in at the mouth of retort, and mixed
at once with the oxide. The charge may then be pushed into close contact at one
end of the retort, till the Ammonia was entirely evolved, then spread over the retort
as described.
I have found it better however, to use the oxide of manganese alone, and to pass a

page_text: current of dry, and cold, or hot air, through the retort from the commencement of
the operation of charging with Ammonic Chloride, to the end of process, for the
Ammonia, in order to remove the Ammonia from the retort as formed. This
gives better results and no loss of Ammonia. Beginning with a temperature of
about 130° C and finishing for the Ammonia at about 325° C at which
point all the Ammonia would be completely evolved. Then shutting and
opening the valves as described and passing steam at the temperature described,
In general all the labour required of the workman, after charging the retort,
would be to keep the temperature below 350° C and stir once or twice till the
Ammonia was evolved then to shut the valves leading to the absorbing apparatus and
open those leading to the condensing chambers, passing steam at same time over the
residue. If the retort be heated by a self-feeding and practically automatic coke
furnace, with properly arranged flues, a workman of ordinary intelligence could well
manage this first temperature with a nercurial thermometer, placed through the door
of the retort.
It would be necessary to start with an excess of oxide or oxides. The proportions
I prefer for mixing, is one of Ammonic Chloride, to four of the oxide. This will
ensure the complete decomposition of the Chlorides, or oxy Chlorides in residue one,
when necessary before washing from Common salt, and also prevent fusion of Chlorides
and sticking to the retort.
Besides the oxides above named or their mixtures, other heavy oxides, and oxides of
the alkaline earth metals, may sometimes be used with advantage. Also the salts
formed from these oxides, or a mixture of any or all of these, in any proportions, may
sometimes be used with advantage, and always preferably in powder as described. By
the heavy oxides, I mean those of lead, copper, tin, bismuth, iron, nickel cobalt, man-
ganese, zinc, and aluminium and others of the like properties. By the alkaline Earths
I mean the oxides of Calcium, barium, stontium, and mangnesium, and others of the
similar properties.
The different varieties of clay when purified from iron may sometimes be used with
advantage.
I however prefer those oxides or mixtures of oxides which are not volatile nor
fusible at this temperature employed, and whoso Chlorides are not volatile at this
temperature, and for this purpose I have found that trimanganic tetroxide (and the
dioxide) of manganese alone, or mixed with magnesic oxide, and cobalt oxide, alone
or mixed with magnesic oxide, or a mixture of all these oxides, are among the best in
giving the equivalent of Ammonia and in ease and low temperature at which they
part with their Hydrochloric Acid. But magnesia reacts somewhat on the retort when
one of fireclay is used. The Chloride of Cobalt is slightly volatile at the temperature
employed, and the oxide of Nickel requires a higher temperature for the evolution of
the Ammonia and Hydrochloric Acid. For these and the following reasons I prefer
the trimanganic tetroxide (and dioxide) to all others in the method of mixtures,
where it has special advantages. Its specific heat is low. It evolves Ammonia at a
low temperature. From 130° C to 200° C most of the Ammonia is expelled, and loss
thus prevented. It is equal to a mixture of the higher, and lower oxides of manganese,
or these held together by a very feeble affinity.
The apparatus I would use, is a fireclay retort, of special manufacture, sufficiently
nonporous to prevent the Animonia passing through it into the fire; or other suitable
furnace; such retorts may be worked in series as in gas works, and through them air
may be drawn or blown as described, and passed when necessary in a heated state
over the contents of the retort; or a retort itself heated may be used to supply heated
air, or oxygen to a series of such retorts as most convenient. The air may be supplied
by a fan, or pump or other kind of blowing machine. I prefer however for the air to
to be drawn through the retort by an exhauster, during the evolution of Ammonia,
and then to use a blower during the evolution of the Hydrochloric Acid, and as the
temperature would require to be at first under control, these retorts may be heated by
coal gas, but I prefer to heat them, with a self-feeding coke furnace as above mentioned,
as this might be done at about one twentieth the cost of gas. The temperature

page_text: required wonld be for the evolution of Ammonia below 350° C (about 130° C to 250°C
at first) for the evolution of the Hydrochloric Acid about 250° C to 350°.
I prefer these retorts set horizontally. They should have covers at each end with
pipes for the passage in and out of the gases. These pipes should be connected with
the apparatus for absorbing the Ammonia, in the soda Ammonia process, and also.
with the conduits leading to the Hydrochloric Acid condensing chambers. When the
evolution of the Ammonia had ceased, and then dry air passed over the residue, stirring
it at the same time, or following the process of aspirating air through retort from the
beginning to the end of process, for the Ammonia, the valves in the conduits leading
to the absorbing apparatus may be shut and those in the conduit leading to the con-
densing chambers may be opened, then blowing steam through retort at a suitable
temperature as described and passing the Hydrochloric Acid, into the Condensing
towers or otherwise using it.
The lime now used, for the evolution of the Ammonia, is thus saved, and the
Chlorine fully and completely recovered, as Hydrochloric-Acid, for no other cost, than
the heat and labour, required, and the wear and tear of retorts.
The number of times necessary to wash the residual oxide or oxides from common
salt, may be considerably diminished, by removing the common salt which is first
precipitated in the evaporation of the mother liquor, in the soda Ammonia process, and
washing it from adhering Ammonic Chloride, in the brine about to be used for the
absorption of the Ammonia. The residue of the mother liquor on evaporation, would
contain but little common salt, and the necessity of often washing the residual oxide
would thus be avoided.
It would be better however, to avoid altogether this necessity, by charging the retort
with Ammonic Chloride free from common salt. By igniting the salts got from the
mother liquor of the soda Ammonia process, and subliming the Ammonic Chloride,
the latter would be obtained free from Common salt, and the necessity of washing
altogether avoided. The extra heat required for this purpose, would be considerably
less, than the extra heat expanded in furnacing the Ammonic Chloride with sodic
Chloride, than in furnacing it alone. The extra heat necessary, for subliming the
Ammonic Chloride may in a large measure be regained, for other uses, and against it
is to be placed the gain in fuel, in this process, by the low temperature employed for
the evolution of the Ammonia and other ways. An indicator consisting of a glass
tube may be joined to or placed in the Ammonia conduit. If this contained titmus it
would reveal when all Ammonia was evolved and Hydrochloric Acid appeared, as
it sometimes does on the passage of air soon after the Ammonia has been quite
evolved. The workman would then simply shut the valves in the Ammonia conduit,
and open those leading to the condensing chambers.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is.
1st. The process of obtaining Ammonia and Hydrochloric Acid from Ammonium
Chloride, by the method of mixtures, which consists in mixing the Ammonic Chloride
preferably in powder, with the oxides of manganese preferably in powder,
or with one
or several of the oxides following, viz., Nickel, iron, cobalt,
Bismuth, Zinc, Copper, Aluminium, Barium, Stontium, Calcium, and magnesium
and others of the like properties, or with mixtures of any or all of these, or by mixing
the Ammonic Chloride in powder with one or several of the salts formed from those
oxides; or clay, purified from iron, mixed with Ammonic Chloride, or a mixture of
any or all of the above: then heating the mixtures or mixture in a suitable furnace or
retort, at a low temperature as described, whereby the Ammonia evolved is saved:
Then stirring the residue, and passing cold and dry air through the retort to expel
any residual Ammonia and undecomposed Ammonic Chloride, then shutting and
opening the valves as described, and passing steam at a suitable temperature through
retort, whereby the Hydrochloric Acid is evolved, and then beginning the round of
operations anew,

page_text: 2nd. The process of obtaining Ammonia and Hydrochloric Acid, from Ammonium
Chloride, by the method of mixtures, which consists in mixing Ammonic Chloride,
preferably in powder, with the Oxides and salts, or their mixtures, as mentioned in
claim one; and heating these in a suitable furnace at a temperature during evolution
of Ammonia of 130° C to 200° C and after raising it to about 325° C when manganese
is the oxide used; at the same time passing cold, or hot and dry air, through the retort
from the commencement and throughout the whole operation, for the Ammonia, wherby
the Ammonia is at once expelled from retort as formed and saved; and when all the
Ammonia is evolved then opening and shuting the valves as described, and passing
steam at a suitable temperature through the retort as described, to obtain Hydro-
chloric Acid; and then beginning the round of operations afresh.
3rd. The process of obtaining Ammonia and Hydrochloric Acid from Ammonium
Chloride, in the method of mixtures, which consists in mixing intimately in powder,
and at first in the cold and dry way, Ammonium Chloride, with one or several of the
oxides or salts in Claim 1 or their mixtures and heating them at a low temperature,
wherby the Ammonia evolved, is saved, and the oxide converted into Chloride, or
Oxy Chloride, and then passing steam as described through the retort to obtain
Hydrochloric Acid.
4th. The improvement in the process of obtaining Ammonia, in the method of
mixtures, from Ammonium Chloride, which consists in passing cold, and dry air, from
the commencement to the end of the operation for the Ammonia through the retort,
containing the before mentioned oxides or mixtures, heated to a low temperature, thus
expelling the Ammonia from the retort as soon as formed, and removing it from the
reducing action of the oxide and other means of loss.
5th. The improvement in the process of obtaining Ammonia from Ammonium
Chloride, in the method of mixtures, which consists in expelling residual Ammonia,
and undecomposed Ammonia Chloride from the retort by passing through the retort,
towards the end only of the operation for the Ammonia, cold and dry air, stirring
the residue, and keeping the temperature of the retort below the point necessary for
evolution of the Chlorine; which in the case of Manganese oxide is about 350° C.
6th. The improvement in the process of obtaining Hydrochloric Acid from Ammonic
Chloride, in the method of mixtures, which consists in stirring the residue two, to
bring it in contact with the steam to obtain complete evolution of the Hydrochloric
Acid when necessary (as before washing) and complete oxidization on the passage of
steam as described.
7th. In the production of Ammonia, and Hydrochloric Acid, from Ammonic
Chloride, by the method of mixtures, the use of the oxides (or their equivalents) of
the composition M. O, and MO, (got by reduction or otherwise) whereby the
Ammonia is saved, at the low temperature employed, and an easier yield of Hydro-
chloric Acid obtained at this temperature.
8th. The process of obtaining Ammonia and Hydrochloric Acid successively, from
Ammonium Chloride, which consists in mixing Ammonium Chloride, with one or
several of the oxides, or salts mentioned in claim 1, heating them in a furnace or
retort, at a low temperature, for the Ammonia, passing cold (or hot) and 'dry air
through the retort, or chamber from the beginning to the end of process, for the
Ammonia only; and then steam for the Hydrochloric Acid; repeating the process
continuously, using the same oxides or mixtures of oxides, or salts over and over again
repeatedly.
FREDERICK BALE,
Coventry Hospital,
Droitwich.