IMPROVEMENTS IN THE MANU- FACTURE OF CERTAIN ALKALINE CARBONATES AND IN THE USEFUL APPLICATION. OF SUCH CARBONATES
Year: 1854

page_text: LETTERS PATENT to William Gossage, of Widnes, in the County of
Lancaster, Chemist, for the Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF CERTAIN ALKALINE CARBONATES AND IN THE USEFUL APPLICATION.
OF SUCH CARBONATES."
Dated the 21st February 1854.
PROVISIONAL SPECIFICATION left by the said William Gossage at
the Office of the Commissioners of Patents, with his Petition, on the
21st February 1854.
I WILLIAM GOSSAGE of Widnes in the County of Lancaster do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF CERTAIN ALKALINE CARBONATES AND IN THE USEFUL APPLICATION OF SUCH CAR-
BONATES" to be as follows:-
The alkaline carbonates to the manufacture of which my improvements are
applicable are the bi-carbonate and sesqui-carbonate of potash; the bi-car-
bonate and sesqui-carbonate of soda; and the bi-carbonate and sesqui-carbonate
of ammonia.
In proceeding to manufacture sesqui-carbonate or bi-carbonate of potash
according to my Invention I prepare a solution containing about one part of
ordinary carbonate of potash in 3 parts of water and I cause this solution to
be passed thro' a high vessel or tower (which I call an "absorbing tower ")
filled with small pebble stones or pieces of coke the solution being so distributed
at the upper part of such absorbing tower that it descends slowly and regularly
18056-1.

page_text: through the bed of stones or coke contained therein and thus become spread
in thin films over the surfaces of such stones or coke and presents an enor-
mous extent of moistened surfaces to gases which may be passed thro' such
absorbing tower. I provide a furnace suitable for burning coal or coke or
other carbon in such manner that the gaseous products of such combustion
may be free or nearly free from unconsumed carbon and I cause such gaseous
products to become cooled by passing them through metallic pipes and I filter
them through moistened coke contained in a suitable vessel. I conduct the
cooled gases into the lower part of the said "absorbing tower" and by means
of a proper draught at the upper part of such tower I cause such gases to ascend
through the interstices existing between the materials contained therein at the
same time that a solution of carbonate of potash is descending in thin films
thro' such tower and thus the gases and fluid are brought into intimate
contact with each other and as these gases contain carbonic acid gas (produced
by the combustion of carbon) a portion of this gas becomes absorbed by the
solution of carbonate of potash and converts this into sesqui-carbonate or
bi-carbonate of potash or a mixture of these two compounds. I regulate
the quantity of solution of carbonate of potash and that of the gaseous products
of combustion admitted into the "absorbing tower" accordingly as I wish
to produce sesqui-carbonate or bi-carbonate of potash preferring that these
quantities shall be so proportioned to each other that the solution on passing
from the absorbing tower shall have absorbed as much carbonic acid as will
produce the compound I wish to obtain.
Instead of using a solution of carbonate of potash in the manufacture of
sesqui-carbonate or bi-carbonate of potash I also manufacture these last-
named compounds by exposing solid carbonate of potash (in the state of powder
and slightly moistened with water) to carbonic acid gas obtained by the
combustion of carbon-For this purpose I prefer to employ an apparatus
consisting of a large chamber having suitable arrangements for supporting a
great number of shallow trays on which I place the moistened carbonate of
potash in layers of about one inch thick and I conduct cooled gases which
have been produced by the combustion of carbon into such chamber at one
end thereof and I connect the opposite end of the chamber with a suitable
draught so as to occasion a continuous current of gases to be drawn through
such chamber. Carbonic acid becomes absorbed by the carbonate of potash and
converts this into sesqui-carbonate or bi-carbonate of potash according to the
quantity of gas absorbed. I facilitate the absorption of carbonic acid by
raking the moistened carbonate on the trays so as to change the surfaces
exposed to the current of gases.

page_text: In proceeding to manufacture sesqui-carbonate or bi-carbonate of soda
according to my Invention I can use a solution of carbonate of soda and
expose this solution to carbonic acid gas (generated by the combustion of
carbon) in an absorbing tower such as I have herein-before mentioned for the
manufacture of sesqui-carbonate and bi-carbonate of potash but I prefer to
effect this manufacture by exposing solid carbonate of soda (moistened with
water) to such carbonic acid gas on trays placed in a chamber conducting this
operation in the same manner as I have herein-before described for the
manufacture of sesqui-carbonate or bi-carbonate of potash from solid carbonate
of potash.
"
In proceeding to manufacture sesqui-carbonate or bi-carbonate of ammonia
according to one of the methods comprised in my Invention I introduce
ammoniacal gas (obtained by the decomposition of sal ammoniac or some
other suitable salt of ammonia) into the lower part of such a vessel as I have
herein-before described and designated as an absorbing tower" and at the
same time I introduce into the same part of such tower a supply of carbonic
acid gas (obtained by the combustion of carbon) and I cause water to be
introduced into the upper part of such tower so that the materials contained
therein shall be continuously moistened therewith and shall present films of
liquor spread on such materials in a most favorable condition for absorbing
the gases passing through such tower and thereby producing sesqui-carbonate
or bi-carbonate of ammonia I apply a suitable draught to the upper part of
such tower and I modify the proportionate quantities of carbonic acid gas and
of ammoniacal gas admitted therein accordingly as I wish to produce sesqui-
carbonate or bi-carbonate of ammonia and I prefer to admit such a quantity
of water at the upper part of such tower as will be just sufficient to dissolve
the compound formed.
In place of manufacturing sesqui-carbonate or bi-carbonate of ammonia in
the state of solution in water I also produce these compounds in a solid state
by means of my Invention. For this purpose I introduce ammoniacal gas
(obtained by the decomposition of sal ammoniac or some other salt of ammonia)
into a large chamber and at the same time I introduce therein a supply of
carbonic acid gas (obtained by the combustion of carbon) and these gases
becoming mingled together in such chamber produce solid sesqui-carbonate or
bi-carbonate of ammonia according to the relative proportions of the two
gases which may be introduced therein and solid sesqui-carbonate or bi-car-
bonate of ammonia becomes deposited in such chamber At the part of the
chamber most distant from that at which the gases are introduced I apply a
suitable draft to draw off the uncondensed gases proceeding from such

page_text: chamber and I cause such gases to be passed through an "absorbing tower
such as I have herein-before described the materials contained in such tower
being moistened with a supply of water by means of which loss of ammonia is
prevented.
In effecting that part of my Invention which relates to "the useful applica-
tion of such carbonates " I apply sesqui-carbonate or bi-carbonate of ammonia
(obtained from ammoniacal gas by the processes herein-before described) to
the decomposition of common salt for the production of sesqui-carbonate
ór bi-carbonate of soda. When I use sesqui-carbonate or bi-carbonate of
ammonia in solution for decomposing common salt I add to such solution the
proper equivalent proportion of dry common salt and I cause the mixture to
be agitated in a close vessel until the decomposition is effected. When I use
solid sesqui-carbonate or bi-carbonate of ammonia for effecting such decompo-
sition of common salt I prefer to dissolve the common salt in water and I
use the proper equivalent proportions of the two compounds and I cause the
mixture to be agitated in a close vessel until the decomposition is effected.
After the decomposition of common salt is effected by either of these modes of
proceeding I transfer the mixture to a vessel in which the sesqui-carbonate or
bi-carbonate of soda is allowed to subside from the solution of sal-ammoniac
produced by such decomposition and I draw off such solution of sal-ammoniac
and I decompose the sal-ammoniac by mixing the solution with caustic lime
and applying heat to the mixture and thereby I obtain ammoniacal gas which
I apply to the reproduction of sesqui-carbonate or bi-carbonate of ammonia in
the manner herein-before described or by the means herein-after mentioned. I
separate solution of sal-ammoniac from the deposited sesqui-carbonate or bi-car-
bonate of soda by washing this with water or with solution of sesqui-carbonate
or bi-carbonate of soda and I thus obtain as a residuum sesqui-carbonate or
bi-carbonate of soda in a marketable form either of which compounds can be
reduced to the state of carbonate by heat in which case I prefer to conduct
the heating operation in an iron retort and to employ the carbonic acid evolved
for the production of a further portion of sesqui-carbonate or bi-carbonate of
ammonia.
In further effecting that part of my Invention which relates to the "useful
application of such carbonates "I employ sesqui-carbonates and bi-carbonates
of potash and soda for supplying pure carbonic acid gas to be applied to the
production of sesqui-carbonate or bi-carbonate of ammonia for the purpose of
applying such product or products to the decomposition of common salt. In
carrying into effect this part of my Invention I subject sesqui-carbonate or
bi-carbonate of potash or of soda to heat so as to expel therefrom carbonic

page_text: acid gas and I cause this gas to be received in a vessel containing a solution
of common salt and at the same time I introduce into such vessel ammoniacal
gas (obtained by the decomposition of sal-ammoniac) and by the combination
of these gases in suitable proportions I produce sesqui-carbonate or bi-car-
bonate of ammonia which effects the decomposition of common salt and the
consequent production of sesqui-carbonate or bi-carbonate of soda & muriate
of ammonia
A Patent was granted to Harrison Grey Dyar and John Hemming in the
year 1838 for their "Invention of Improvements in the Manufacture of Car-
bonate of Soda" the term of such Patent right has now expired.
In the Specification of such Invention they describe the means by which
common salt is decomposed by sesqui-carbonate or bi-carbonate of ammonia.
This Invention was carried into effect on the large scale but it was found to
be not useful in consequence of the great loss of ammonia which occurred in
the operations and the want of a supply of pure carbonic acid gas to be
procured at a low cost-and in consequence of these circumstances the Inven-
tion was abandoned. This part of my Invention provides for the prevention
of loss of ammonia also for the supply of carbonic acid gas procured at a low
cost.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Gossage in the Great Seal Patent Office on the
21st August 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME I WILLIAM
GoSSAGE of Widnes in the County of Lancaster Chemist send greeting
WHEREAS Her most Excellent Majesty Queen Victoria by Her Letters
Patent bearing date the Twenty-first day of February in the year of our Lord
One thousand eight hundred and fifty-four in the seventeenth year of Her
reign did for Herself Her heirs and successors give and grant unto me
the said William Gossage Her special licence that I the said William
Gossage my executors administrators and assigns or such others as I
the said William Gossage my executors administrators and 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 "IM-
PROVEMENTS IN THE MANUFACTURE OF CERTAIN ALKALINE CARBONATES AND IN THE

page_text: USEFUL APPLICATION OF SUCH CARBONATES" upon the condition (amongst others)
that I the said William Gossage 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 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 William Gossage 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 reference being had to the Drawings hereunto annexed and to the
letters and figures marked thereon (that is to say).
The alkaline carbonates to the manufacture of which my improvements are
applicable are the bi-carbonate and sesqui-carbonate of potash-the bi-car-
bonate sesqui-carbonate and carbonate of soda and the bi-carbonate and
sesqui-carbonate of ammonia-In proceeding to manufacture bi-carbonate or
sesqui-carbonate of potash according to my Invention I prepare a solution
containing about one part of ordinary carbonate of potash dissolved in four
parts of water and I cause such solution to be passed through a vessel or tower
(constructed of wood work lined with lead or of iron plates or other suitable
material and which I will herein-after designate as an "absorbing tower ")
filled with small pebble stones pieces of coke or other suitable material such
solution being distributed at the upper part of the said "absorbing tower" in
such manner that it will descend slowly and regularly through the bed of
material contained therein and thus become diffused in films over the surfaces
of such material and present a large extent of liquid surface to gases which
may be passed through such "absorbing tower "-The construction and ar-
rangement of such towers are similar to those of the towers commonly used
by manufacturers of soda for the condensation of muriatic acid gas and for
which I obtained Letters Patent in the year 1837.-I provide a furnace or fire
grate adapted for burning coal coke or other suitable carbon in such manner
that the gases produced by such combustion may be free (or nearly free) from
unconsumed carbon and I cause such gases to become cooled by passing them
through metallic pipes exposed to the cooling influence of air or water and I
filter the said gases through limestone in small pieces kept moist with water
and contained in a suitable vessel-I conduct the cooled gases thus obtained
into the lower part of the said "absorbing tower" and by means of a proper
draft (obtained by connection with a chimney or otherwise) at the upper part
of such tower I cause such gases to ascend through the interstices existing

page_text: between the pieces of material contained therein at the same time that solution
of carbonate of potash is descending in films diffused over the surfaces of such
material and thus the said gases and solution are brought into intimate contact
with each other and as these gases contain carbonic acid gas (produced by the
combustion of carbon) a portion of this carbonic acid gas becomes combined
with carbonate of potash contained in the solution and thereby produces sesqui-
carbonate or bi-carbonate of potash or a mixture of these two compounds in
solution which runs off from the bottom of the tower by means of a bent pipe
so arranged as to prevent the escape of gas therefrom.
I regulate the quantity of solution of carbonate of potash also of the gases-
(produced by the combustion of carbon) admitted into the said "absorbing
tower" accordingly as I wish to produce sesqui-carbonate or bi-carbonate of
potash preferring that these quantities shall be so proportioned to each other
that the solution on passing from the said "absorbing tower" shall have
absorbed as much carbonic acid as will produce the compound I wish to obtain.―
When I wish to convert sesqui-carbonate of potash into bi-carbonate of potash
I adopt for such purpose the same means which I have herein-before described
as suitable for converting ordinary carbonate of potash into bi-carbonate of
potash-regulating the supply of solution of sesqui-carbonate of potash and of
gases produced by combustion of carbon introduced into the said "absorbing
tower" in suitable proportions. In place of using a solution of carbonate of
potash for the purpose of manufacturing sesqui-carbonate or bi-carbonate
of potash I also manufacture these last-named compounds by exposing ordinary
carbonate of potash slightly moistened with water to carbonic acid gas obtained
by the combustion of carbon-For such purpose I prefer to employ an appa-
ratus consisting of a large air-tight chamber constructed of brick-work set
in cement or of other suitable material which chamber contains a number of
shallow trays (made of sheet iron or other suitable material) on which I place
moistened carbonate of potash in layers of about one inch in thickness. The
said trays are supported one above another leaving space for circulation of
gases between the same-I conduct cooled gases which have been produced by
the combustion of carbon (as herein-before described) into such chamber at one
end thereof and I connect the opposite end of the said chamber with a suitable
draft so as to occasion a continuous current of the said cooled gases to be drawn
through such chamber-Carbonic acid gas (previously contained in the said
cooled gases) becomes absorbed by the moistened carbonate of potash and
converts this into sesqui-carbonate or bi-carbonate of potash according to the
quantity of such gas absorbed.. I facilitate the absorption of carbonic acid
gas by
raking the moistened carbonate of potash (exposed on trays in the said chamber)

page_text: so as to change the surface of the carbonate which is exposed to the gases
passing through such chamber.
When I wish to prepare for sale such sesqui-carbonate or bi-carbonate of
potash obtained by the means herein-before described I subject the same to
the process of crystallization (after previous solution in water if needful) and
I repeat such solution and crystallization until the salt obtained is of such
quality as to be suitable for the market.-During the concentration of such
.solutions preparatory to crystallization I avoid the application of such tem-
perature as would occasion the liberation of carbonic acid gas from the same.
In manufacturing sesqui-carbonate or bi-carbonate of soda according to my
Invention I can use a solution of ordinary carbonate of soda commonly called
soda ash (in the proportion of about one part of carbonate of soda to twelve
parts of water) and I expose this solution to carbonic acid gas (generated by
the combustion of carbon) in an "absorbing tower" in the same manner I have
herein-before described for the manufacture of sesqui-carbonate and bi-carbonate
of potash in solution from ordinary carbonate of potash-In the same manner
I also prepare solution of bi-carbonate of soda by the use of solution of sesqui-
carbonate of soda. But I prefer to effect such manufacture of sesqui-carbonate
and bi-carbonate of soda by exposing ordinary carbonate of soda (moistened
with water) to such carbonic acid gas on trays placed in an air-tight chamber
and I conduct this operation in the same manner as I have herein-before
described for the manufacture of sesqui-carbonate and bi-carbonate of potash
from moistened carbonate of potash-In manufacturing sesqui-carbonate or
bi-carbonate of ammonia according to one of the methods comprised in my
Invention I introduce ammonia in the gaseous state (obtained by the decom-
position of sal ammoniac or some other suitable salt of ammonia by means of
lime) into such an apparatus as I have herein-before described and designated
as an "absorbing tower" such introduction being effected at about the middle
(as respects height) of such "absorbing tower" and I also introduce into the
lower part of such tower a supply of carbonic acid gas (obtained by the com-
bustion of carbon) and I cause water to be supplied into such tower at the
upper part thereof in such manner that the materials contained therein shall
be continuously moistened therewith and shall present films of liquor diffused
over such materials in a favourable condition for the absorption of gases passing
through such "absorbing tower" and thereby producing sesqui-carbonate or
bi-carbonate of ammonia in solution. I cause the upper part of such tower to
be connected with a suitable draft so as to induce the passage of gases through
the same and I modify the proportionate quantities of carbonic acid gas and of
ammoniacal gas admitted therein accordingly as I wish to produce sesqui-

page_text: carbonate or bi-carbonate of ammonia and I prefer to supply such a quantity
of water at the upper part of such tower as will be just sufficient to dissolve the
compound formed.
I connect the "absorbing tower" (into which I introduce carbonic acid gas
and ammoniacal gas for the purpose of manufacturing sesqui-carbonate or
bi-carbonate of ammonia) with a second "absorbing tower" of a similar con-
struction into which I introduce muriatic acid either in the liquid or gaseous
state and I cause the gases proceeding from the first "absorbing tower" to
pass through such second "absorbing tower" and I thereby arrest any ammonia
which may be contained in such gases and cause this to become combined
with muriatic acid producing solution of sal ammoniac. I supply water to such
second "absorbing tower" (when required) in sufficient quantity to dissolve the
sal-ammoniac produced therein.
In place of manufacturing sesqui-carbonate or bi-carbonate of ammonia in
the state of solution in water I also produce these compounds in a solid state
by means of my Invention. For such purpose I introduce ammoniacal gas
(obtained by the decomposition of sal-ammoniac or of some other suitable salt
of ammonia by means of lime) into a large air-tight chamber constructed of
brick-work set in cement or of other suitable material and at the same time I
introduce therein a supply of carbonic acid gas (obtained by the combustion of
carbon) and these gases becoming mingled together in such chamber produce
sesqui-carbonate or bi-carbonate of ammonia according to the relative pro-
portions of the two gases which may be introduced therein and solid sesqui-
carbonate or bi-carbonate of ammonia becomes deposited in such chamber. To
the part of such chamber which is the most distant from that at which ammo-
niacal gas and carbonic acid gas are introduced I adapt a suitable draft for
the purpose of drawing off uncondensed gases proceeding from such chamber
and I cause such uncondensed gases to be passed through an "absorbing tower"
(such as I have herein-before described) the materials contained in such tower
being continually moistened with a supply of water or of liquid muriatic acid
by means of which loss of ammonia is prevented.
In place of manufacturing sesqui-carbonate or bi-carbonate of ammonia by
the use of impure carbonic acid gas (obtained by the combustion of carbon)
and ammoniacal gas, I also manufacture these compounds by combining
ammoniacal gas with pure carbonic acid gas obtained by heating the sesqui-
carbonates or bi-carbonates of potash or of soda which sesqui-carbonates or
-bi-carbonates have been previously obtained by the use of impure carbonic acid
gas produced by the combustion of carbon. When I wish to obtain sesqui-
carbonate or bi-carbonate of ammonia in solution by the use of purc carbonic

page_text: acid gas I prefer to use such a tower as I have herein-before described as
suitable for the production of such compounds by the use of impure carbonic
acid gas and I introduce carbonic acid gas and ammoniacal gas therein in
suitable proportions to form the compound which I wish to obtain and I
introduce sufficient water into the upper part of such tower to dissolve the
compound so produced.
When I wish to obtain these compounds in a solid state I prefer to use
such a chamber as I have herein-before described as suitable for the production
of such compounds by the use of impure carbonic acid gas-and in both cases
I conduct any uncondensed gases proceeding from such tower or chamber
through another tower for the purpose of arresting any ammonia which may
be contained in such uncondensed gases as herein-before described.
My improvements in the useful application of certain alkaline carbonates
comprize the use of sesqui-carbonate and bi-carbonate of potash and sesqui-
carbonate and bi-carbonate of soda (obtained by the means herein-before
described) for the purpose of supplying pure carbonic acid gas by the decom-
position of these compounds by heat and the application of such pure carbonic
acid gas so obtained to the formation of sesqui-carbonate or bi-carbonate of
ammonia by the union of such gas with ammonia. Such improvements also
comprize the use of sesqui-carbonate and bi-carbonate of ammonia so obtained
also of the same compounds obtained by the use of ammoniacal gas and impure
carbonic acid gas as herein-before described for the purpose of decomposing
common salt and producing sesqui-carbonate or bi-carbonate of soda and sal-
ammoniac by such decomposition.
I would explain that the decomposition of common salt by means of sesqui-
carbonate or bi-carbonate of ammonia is dependent on the relative solubility
in water of the sal-ammoniac and sesqui-carbonate or bi-carbonate of soda
produced by such decomposition and as these last-named compounds are
neither of them insoluble in water the quantity of such compounds to be
obtained separately is dependent on the proportionate quantity of water present―
It is therefore desirable to reduce this proportionate quantity of water to as
little as may be just sufficient to retain in solution the sal ammoniac produced-
I find this to be effected when I have about three parts of water for each one
part of common salt present in the mixture employed
These proportions are obtained sufficiently near when I use a saturated
solution of common salt to mix with dry sesqui-carbonate or bi-carbonate of am-
monia or with ammoniacal gas and carbonic acid gas as herein-after described-
When so using a saturated solution of common salt I add thereto as much dry
sesqui-carbonate or bi-carbonate of ammonia (in powder) as contains seventeen

page_text: parts of ammonia for each two hundred and forty parts of such saturated solu-
tion of common salt or instead of adding dry sesqui-carbonate or bi-carbonate
of ammonia to such common salt I add thereto as much ammoniacal gas as will
be liberated by the decomposition of fifty-four parts of sal-ammoniac (by
means of lime) for each two hundred and forty parts of saturated solution of
common salt and in all cases I inject pure carbonic acid gas (by means of an
air pump) into the closed vessel in which I effect such mixing until a pressure
of at least ten pounds per square inch is obtained in such vessel at which
pressure I find that (with suitable agitation) any sesqui-carbonate of soda
present in the mixture becomes converted into bi-carbonate of soda.
When I use sesqui-carbonate of ammonia or bi-carbonate of ammonia in
solution (obtained by some of the means herein-before described for such purpose
and which solution I prefer to have in a state of full saturation) I add common
salt to such solution in the proportion of about sixty parts of common salt for
each seventeen parts of ammonia contained therein I also make a further
addition of common salt thereto so as to make the total quantity of common
salt present in the mixture equal to one-third of the total quantity of water
contained therein and I note particularly the quantity of such further addition
of common salt.-I introduce as much ammoniacal gas into such mixture as
will be liberated by the decomposition of fifty-four parts of sal ammoniac (by
means of lime) for each sixty parts of common salt which have been so added
to the original mixture of common salt and solution of sesqui-carbonate or
bi-carbonate of ammonia. I inject pure carbonic acid gas (by means of an air
pump) into the closed vessel in which I effect such mixing until a pressure of
at least ten pounds per square inch is obtained in such vessel at which pressure
I find that (with suitable agitation of the mixture) sesqui-carbonate of soda
becomes converted into bi-carbonate of soda
I will herein-after describe an apparatus of such construction as I prefer to
use for effecting the decomposition of common salt by means of sesqui-car-
bonate or bi-carbonate of ammonia but I can also effect such decomposition
by the use of a vessel capable of being closed within which a revolving
agitator having projecting arms is adapted-The axis of such agitator passing
through a stuffing box attached to such vessel and rotative motion being
communicated to such axis by the use of suitable mechanical arrangements―
I designate such vessel a "mixing vessel "
After completing the decomposition of a charge of common salt and sesqui-
carbonate or bi-carbonate of ammonia in such "mixing vessel" in the manner
herein-before described so as to produce bi-carbonate of soda I transfer the
mixture produced into another vessel capable of being closed and which I

page_text: -
designate as a "filtering vessel "-Such "filtering vessel" has a perforated
diaphragm near its lower part on which diaphragm is placed a linen or cotton
cloth to serve the purpose of a filter and thus prevent the passage of bi-car-
bonate of soda through the perforations in the said diaphragm-I connect
the said "filtering vessel" (by means of a pipe attached thereto below the said
diaphragm) with a second vessel also capable of being closed from the atmo-
sphere through which pipe fluid can flow into the said "second vessel "-I also
connect the upper parts of the said two vessels by means of a pipe so as to
equalize the pressure of gases contained therein when the said vessels have
been closed-Such arrangements having been made and a quantity of such
mixture having been transferred as quickly as possible from the said "mixing
.vessel" into the said "filtering vessel" and such "filtering vessel" having
been connected with the second vessel herein-before mentioned and the said
vessels having been closed from the atmosphere I allow fluid to drain or filter
from such mixture-Such fluid contains sal-ammoniac also some bi-carbonate
of soda in solution-After such fluid has drained from the mixture I intro-
duce solution of bi-carbonate of soda into the said "filtering vessel" and I
allow such solution to drain through the mass of undissolved bi-carbonate of
soda contained therein until such bi-carbonate is sufficiently deprived of sal
ammoniac to render it suitable for sale-I then abstract such washed bi-
carbonate of soda from the said "filtering vessel" and if I wish to sell this in
the state of bi-carbonate of soda I dry it at a low temperature and grind
the dried product to a fine powder-If I wish to sell the product in the state
of ordinary carbonate of soda I introduce such washed bi-carbonate of soda
into iron retorts (similar to the retorts used for the manufacture of coal
gas) and I apply heat thereto until such bi-carbonate of soda becomes con-
verted into ordinary carbonate of soda fit for sale and I collect and apply
carbonic acid gas liberated by such heating of bi-carbonate of soda in the
manner and for the purposes herein-mentioned.
The solution which passes from the said "filtering vessel" by drainage
after the introduction of a charge of the said mixture therein also the first
portions of fluid which drain off after the introduction of solution of bi-car-
bonate of soda contain nearly all the sal-ammoniac produced by such decom-
position of common salt-The last portions of fluid passing from the said
vessel contain but little sal-ammoniac-I use such last portions of fluid either
for dissolving a fresh portion of common salt to be used in a succeeding
operation or I introduce such fluid into the said "absorbing tower" in place
of water to form solution of sesqui-carbonate or bi-carbonate of ammonia
I introduce the fluid containing much sal-ammoniac into a metallic still and

page_text: "
add thereto a suitable quantity of fresh slaked lime taking care that this shall
be more than sufficient to decompose all the sal-ammoniac present therein-I
apply heat to such still either by the injection of steam or by means of fire
underneath I adopt a revolving agitator to such still with which I agitate
its contents to assist the extrication of ammoniacal gas therefrom-I conduct
such ammoniacal gas as it is evolved into a refrigerator for the purpose of
condensing aqueous vapour carried over with the ammoniacal gas and I
subsequently filter the said gas through pieces of coke contained in a vessel
which I call a "filtering vessel" for the purpose of separating water from
such gas-I place the said refrigerator and filtering vessel containing coke at
such an elevation (relatively to the ammonia still) that water produced by
condensation therein can flow back into such still-I conduct ammoniacal
gas which has been cooled and filtered as above mentioned either into the
'absorbing tower " herein-before described for the purpose of producing
solution of sesqui-carbonate or bi-carbonate of ammonia or I introduce such
gas into the "mixing vessel" herein-before mentioned for the purpose of
producing sesqui-carbonate or bi-carbonate of ammonia therein-I have
herein-before described the means by which I manufacture bi-carbonate of
potash in solution by the use of a solution containing ordinary carbonate of
potash or sesqui-carbonate of potash also the means by which I obtain bi-
carbonate of soda in solution by the use of a solution containing ordinary
carbonate of soda or sesqui-carbonate of soda-When I use such solutions of
bi-carbonates for the production of pure carbonic acid gas. I transfer the
solution employed into a metallic still provided with a refrigerator and a
filtering vessel containing coke for the purpose of condensing and separating
aqueous vapour from the carbonic acid gas evolved-This refrigerator and
filtering vessel containing coke are constructed and arranged similarly to the
refrigerator and filtering vessel which I have herein-before described as being
adapted to the still which I use for obtaining ammoniacal gas from sal-
ammoniac-I apply heat to the solution of bi-carbonate which I employ
either by injection of steam therein or by use of fire underneath the still
containing the same-By these means pure carbonic acid gas is liberated
from the bi-carbonate employed and this is converted into sesqui-carbonate-
I conduct carbonic acid gas so obtained (after this has been cooled and filtered
as above mentioned) either into the "absorbing tower" herein-before
described for the purpose of producing solution of sesqui-carbonate or bi-
carbonate of ammonia or I introduce such gas into the "mixing vessel"
herein-before mentioned for the purpose of producing sesqui-carbonate or
bi-carbonate of ammonia or bi-carbonate of soda therein-I cause the solu-

page_text: tion of sesqui-carbonate of potash or of soda remaining in the said still after
the extrication of carbonic acid gas therefrom to become cooled and I then
reconvert such sesqui-carbonate in the said solution into bi-carbonate by the
means herein-before mentioned for such purpose.
I have herein-before described the means by which I manufacture bi-
carbonate of potash and bi-carbonate of soda in the solid state by the use of
ordinary carbonate of potash or ordinary carbonate of soda-When I use such
solid bi-carbonate of potash or bi-carbonate of soda for the production of pure
carbonic acid gas I introduce such solid bi-carbonate into an iron retort
similar to the retorts used in the manufacture of coal gas and I apply heat
thereto so as to expel carbonic acid gas from such bi-carbonate and I thereby
reduce the same into the state of ordinary dry carbonate of potash or of soda-
I conduct carbonic acid gas so obtained (after this has been cooled as herein-
before mentioned) either into the "absorbing tower" herein-before described
for the purpose of producing solution of sesqui-carbonate or bi-carbonate of
'ammonia or I introduce such gas into the "mixing vessel" herein-before
mentioned for the purpose of producing sesqui-carbonate or bi-carbonate of
ammonia or bi-carbonate of soda therein
The Drawings hereunto annexed represent such an apparatus as I prefer to
use as a "mixing vessel" for effecting the absorption of ammoniacal gas and
of carbonic acid gas or of either of these gases for the purpose of producing
bi-carbonate of soda by the decomposition of common salt. Figure I is a
vertical section of such apparatus shewing its interior chambers Figure II
is also a vertical section but taken at right angles to Figure I. In these
Figures the same letters and figures of reference are used to indicate similar
parts
The apparatus consists of a cylindrical vessel A divided by partitions into
chambers-A 1 A 2 et cetera―This vessel is mounted upon axles B & C
supported in bearings The axle C is solid and upon this axle a spur wheel
E is fixed and this spur wheel is actuated by a pinion F on a shaft G which
is caused to revolve by some mechanical force and thus slow rotative motion
is communicated to the vessel A-The axle B is hollow and it revolves in
two stuffing boxes K. K-Between these stuffing boxes there exists a space
or chamber M to which two pipes are connected for the conveyance of gas-
The hollow axle B is perforated with apertures corresponding with the
chamber M through which gas is conveyed from the said chamber into the
vessel A-One of the said gas pipes is used for the conveyance of carbonic
acid gas and the other for ammoniacal gas-D D D are openings, closed
with covers, by means of which the materials employed are introduced into or

page_text: withdrawn from the vessel A-In commencing to work with this apparatus I
introduce as much of the fluid mixture of saline compounds that I am about
to operate upon as will fill the vessel A to the line of liquid marked H-J-
By reference to the Drawing it will be seen that as the vessel A is caused to
revolve on its axles in the direction shewn by arrows each chamber will
alternately be brought into the position of the chamber marked A 1 in which
position the fluid mixture of saline compounds is discharged from such
chamber at the same time that gases contained in the vessel A bubble
through such fluid mixture and by these means a suitable mixing of the
saline compounds with the gases contained in the vessel A is occasioned and
thereby absorption of such gases is effected For some period after com-
mencing to work with a new charge of "saline compounds" in a "mixing vessel "
(whether the same be of the construction I prefer to use or an ordinary" mixing
vessel" such as I have herein-before described) I do not find it needful to
subject the gases contained in such vessel to pressure as so long as ammonia-
cal gas as well as carbonic acid gas is supplied to such "mixing vessel" con-
densation of such gases is effected without the aid of pressure but when the
total quantity of ammoniacal gas required for a charge has been introduced
into such "mixing vessel " I then find it advantageous to introduce the remain-
ing quantity of carbonic acid gas requisite for converting the sesqui-carbonate
of soda produced into bi-carbonate of soda by means of an air pump and to
introduce the said gas in such a manner as to occasion a pressure of not less
than ten pounds per square inch therein and for this purpose I prefer to
collect pure carbonic acid gas (obtained by some of the means herein-before
mentioned) in a gas holder and to connect the air pump which I employ for
pumping such gas with the said gas holder.
"
During the condensation of the said gases in the said "mixing vessel a con-
siderable extrication of heat is occasioned it is therefore needful to allow the
mixture therein to become cooled to a temperature not exceeding one hundred
degrees of Fahrenheit's thermometer before abstracting the mixture from
such "mixing vessel "-Such cooling may be effected either by the cooling action
of the surrounding atmosphere or by the external application of cold water
to such "mixing vessel "-In all the operations I have herein-before described
for obtaining bi-carbonate of soda by the decomposition of common salt I
avoid as much as possible all exposure of the saline mixture containing am-
monia to the atmosphere as such exposure would occasion loss of ammonia.
Having now particularly described and ascertained the nature of my said
Invention and the manner in which the same is to be performed by the
foregoing particulars thereof I would have it understood that I do not confine

page_text: myself to the precise details herein-before set forth as these may be modified
to some extent without departing from the nature of my Invention
I claim as my Invention so far as this relates to "improvements in the
manufacture of certain alkaline carbonates"
Firstly The manufacture of bi-carbonate and sesqui-carbonate of potash
from ordinary carbonate of potash also bi-carbonate and sesqui-carbonate of
soda from ordinary carbonate of soda by exposing an aqueous solution of such
ordinary carbonate of potash or carbonate of soda to carbonic acid gas (pro-
duced by the combustion of carbon) by means of such an apparatus as I have
herein-before designated as an "absorbing tower" also the manufacture of
bi-carbonate of potash and bi-carbonate of soda from aqueous solution
of sesqui-carbonate of potash or sesqui-carbonate of soda by the same means.
Secondly The manufacture of bi-carbonate and sesqui-carbonate of potash
from ordinary carbonate of potash also bi-carbonate and sesqui-carbonate of
soda from ordinary carbonate of soda (usually called soda ash) by exposing
such ordinary carbonate of potash or ordinary carbonate of soda when
moistened with water to carbonic acid gas produced by the combustion of
carbon
Thirdly The manufacture of bi-carbonate and sesqui-carbonate of ammonia
in aqueous solution by introducing ammoniacal gas and carbonic acid gas
(produced by the combustion of carbon or produced by the decomposition of
bi-carbonate or sesqui-carbonate of potash or of soda) into such an apparatus
as I have herein-before designated as an "absorbing tower" a proper supply
of water being also introduced into such "absorbing tower."
Fourthly The manufacture of bi-carbonate and sesqui-carbonate of
ammonia in a solid state by the combination of carbonic acid gas (obtained
by the combustion of carbon or obtained by the decomposition of bi-
carbonate or sesqui-carbonate of potash or of soda) with ammoniacal gas
obtained by the decomposition of sal-ammoniac which sal-ammoniac shall
have been produced by the decomposition of common salt with carbonate of
ammonia.
Fifthly The manufacture of bi-carbonate or sesqui-carbonate of ammonia
in solution by the introduction of ammoniacal gas and pure carbonic acid gas
(obtained by the decomposition by heat of bi-carbonate or sesqui-carbonate
of potash or of soda) into such a "mixing vessel" as I have herein-before
described together with a sufficient proportion of water to dissolve the whole
or part of the ammoniacal salt so produced-I further claim as my Invention
so far as this relates to "improvements in the useful application of certain
alkaline carbonates,"

page_text: Firstly The useful application of bi-carbonate and sesqui-carbonate of
potash also of bi-carbonate and sesqui-carbonate of soda (all of these com-
pounds having been previously manufactured according to my Invention) for
the purpose of supplying pure carbonic acid gas by their decomposition by
heat such gas to be applied to the manufacture of sesqui-carbonate or bi-car-
bonate of ammonia such compound or compounds of ammonia so produced
being used for the decomposition of common salt and production thereby of
bi-carbonate or sesqui-carbonate of soda and sal-ammoniac
Secondly The useful application of bi-carbonate and sesqui-carbonate of
ammonia (manufactured according to my Invention as herein-before de-
scribed) for the purpose of decomposing common salt and thereby producing
bi-carbonate or sesqui-carbonate of soda and sal-ammoniac
In witness whereof I the said William Gossage have hereunto set my
hand and seal the Nineteenth day of August in the year of our Lord
One thousand eight hundred and fifty-four