CERTAIN IMPROVEMENTS IN THE PROCESSES OR OPERATIONS CON- NECTED WITH THE MANUFACTURE OF ALKALI FROM COMMON SALT, AND WITH THE USE OF THE PRODUCTS OBTAINED THEREFROM
Year: 1837

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GoSSAGE, of Stoke Prior, in the County of Worcester, Manufacturing Chemist,
send greeting.
WHEREAS Her present most Excellent Majesty hath granted unto me
Her Letters Patent, sealed at Westminster, the Seventeenth day of August,
in the first year of Her reign, for making, using, exercising, and vending,
within that part of the United Kingdom of Great Britain and Ireland called
England, Her Dominion of Wales, and Town of Berwick-upon-Tweed, my
Invention of "CERTAIN IMPROVEMENTS IN THE PROCESSES OR OPERATIONS CON-
NECTED WITH THE MANUFACTURE OF ALKALI FROM COMMON SALT, AND WITH
THE USE OF THE PRODUCTS OBTAINED THEREFROM," subject to the usual proviso
obliging me to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, by an instrument in writing under
my hand and seal, and to cause the same to be inrolled in the High Court of
Chancery within six calendar months next after the date of the said Letters
Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said-
William Gossage, do hereby, describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, as follows, that is
to say:
The manufacture of alkali from common salt, by treating the salt, in the
first operation, with sulphuric acid, and in the second operation decomposing

page_text: the sulphate of soda obtained thereby by means of lime and carbonaceous
matter, is well known. My improvements are in part connected with the
use of the muriatic acid obtained during the first operation above referred
to as part of the processes of manufacturing alkali from common salt, when
the said muriatic acid is applied to act on oxide of manganese. By the action
of muriatic acid on oxide of manganese chlorine gas and muriate of man-
ganese are produced, and by submitting this muriate to certain processes
herein-after indicated I obtain oxide of manganese, which I designate artificial
oxide of manganese, of a quality suitable to be applied again with muriatic
acid for producing chlorine gas. My improvements are also in part connected
with the use of the product obtained by the second operation above referred
to as part of the processes of manufacturing alkali from common salt.
When the crude alkali is lixiviated in the usual way there remains an
undissolved residuum well known to manufacturers as alkali residuum or tank
refuse. This residuum contains sulphuret of calcium, carbonate of lime,
carbon, and some other matters. By the means herein-after described I
obtain from this alkali residuum sulphuretted hydrogen and carbonate of lime,
which may be used as herein-after described.
The decomposition of common salt by means of sulphuric acid may be
effected for the purposes of my improvements in any of the apparatus usually
émployed, which provide for retaining the muriatic acid; but I prefer making
use of certain improved apparatus for which I obtained His late Majesty's
Royal Letters Patent, bearing date the Twenty-fourth day of December, One
thousand eight hundred and thirty-six. One modification of this apparatus, as
described in my Specification of such Patent, which is inrolled in Her
Majesty's High Court of Chancery, consists of a condensing chamber con-
taining siliceous pebbles, in which the muriatic acid gas may be condensed by
water alone, yielding liquid muriatic gas, or by a mixture of water with any
substance or material on which it is desired that the muriatic acid should
effect a chemical action. When I use the said artificial oxide of manganese
(prepared as herein indicated) in this apparatus, I inject a mixture of this
oxide and water, and introduce steam in the manner described in my said
other Specification, and, the oxide being acted upon by the muriatic acid,
chlorine gas and liquid muriate of manganese are obtained as products, and
which may be collected separately, as described in my said former Specifica-
tion. Also when liquid muriatic acid, obtained by condensing the gas with
water alone, is caused to act on oxide of manganese, chlorine gas and liquid
muriate of manganese are obtained as products. The liquid muriate of
manganese being collected, I decompose it by means of hydrate of lime

page_text: and to effect this operation. conveniently I use large shallow open vessels,
each vessel having several shafts fitted with paddles, and extending across
it, and so arranged that rapid motion can be communicated to them. I
introduce into these vessels a quantity of hydrate of lime made into cream
of lime, and I gradually add the liquid muriate of manganese thereto,
and at the same time give motion to the shafts and' paddles, so as to cause a
perfect mixing of the fluids. I prefer to keep. an excess of lime in the
mixture, and by the gradual addition of the liquid muriate of manganese, as
above pointed out, I reduce this excess to a small proportion at the end of
the operation.
During this operation a reaction takes place between the
lime and muriate of inanganese, and hydrated protoxide of manganese and
liquid muriate of lime are produced in mixture. I. expose this mixture to
atmospherical air, from which the hydrated protoxide absorbs oxygen; and I
accelerate this absorption of oxygen by causing the fluid mixture to be pro-
jected into the air in finely divided particles by communicating a rapid rota-
tory motion to the shafts and paddles before mentioned. The absorption of
oxygen converts the hydrated protoxide of manganese into hydrated protoxide,
and the operations which I have described may be continued until the con-
version of the whole is complete. But as the progress of the conversion is
slow towards the end of the operation, I prefer to conclude. when three fourths
or five sixths of the protoxide présent has been so converted. I thus obtain
the artificial oxide of manganese containing sufficient oxygen to make it
suitable for the preparation of chlorine gas. And at this stage of the ope-
ration I separate the greater part of the muriate of lime from the oxide of
magnesia, by allowing the oxide to subside, and afterwards washing. out the
muriate of lime with water. But this separation may in like manner be
effected previously to the conversion above described. I collect the mixture
of oxide and water on filters, and drain off the greatest part of the water,
which leaves the oxide in a state fit to be used with muriatic acid gas or
strong muriatic acid, for the preparation of chlorine; but this oxide still
contains a considerable quantity of water, and if I wish to use the oxide with
muriatic acid of less than full strength, I previously expose the oxide to heat,
for the purpose of drying it, in pans, stoves, or furnaces, at such a temperature
as will not cause oxygen gas to be driven off from the oxide.
As to that part of my Invention which relates to obtaining the artificial
oxide of manganese, and to the use of such oxide with muriatic acid, I do not
confine myself to the use of the apparatus herein-before mentioned for effecting
the object of this part of my Invention, as other apparatus may be employed
for such purpose; nor do I claim any privilege with respect to the said appa-

page_text: ratus; nor do I claim the preparation of protoxide of manganese from its
muriate by means of lime.
As to that part of my Invention which relates to the use of the alkali
residuum, which, as I have already stated, contains sulphuret of calcium and
carbonate of lime, when this residuum is acted upon by muriatic acid, a
mixture of sulphuretted hydrogen gas and carbonic acid gas is evolved; these
mixed gases being placed in contact with another portion of alkali residuum,
the carbonic acid reacts on the sulphuret of calcium and liberates therefrom a
further quantity of sulphuretted hydrogen. Carbonic acid gas being thus
absorbed and abstracted from the mixture of gases, sulphuretted hydrogen gas
is obtained nearly free from carbonic acid gas, and in a state favorable to
undergo combustion, and thereby produce sulphurous acid. In order to
determine the action of muriatic acid on alkali residuum, I bring them in
contact. When I employ muriatic acid in a state of gas, I prefer to use the
condensing apparatus which I have herein-before referred to, as containing
siliceous pebbles, and I introduce the alkali residuum in a finely divided
state mixed with water into this apparatus, in the manner described in my
said former Specification respecting operations with such apparatus and
powdery substances. The gaseous muriatic acid becomes condensed by its
contact with the mixture of alkili residuum and water, and reacts thereon,
evolving sulphuretted hydrogen and carbonic acid gases, and producing
liquid muriate of lime. These products descend through the apparatus,
and the liquid muriate of lime flows off through the liquid passage, whilst
the gases pass off by the gas passage. When I employ liquid muriatic
acid to act on alkali residuum, I mix them together in a suitable vessel
or apparatus, furnished with a pipe or tube for conducting off the
which are evolved, and I thereby obtain liquid muriate of lime, and a mixture
of sulphuretted hydrogen and carbonic acid gases. The mixed gases, as they
pass from the pipe or tube, may at once be caused to undergo combustion,
and thus produce sulphurous acid; but I prefer to abstract carbonic acid
from such mixture by means of another portion of alkali residuum, and I
effect this by an apparatus similar to that which is employed for the purifi-
cation of coal gas by what is called " dry lime purification." This appa-
ratus consists of vessels containing a number of perforated trays or shelves,
and I place the alkali residuum in thin layers or strata upon these trays
or shelves, and then introduce the mixed gases, which percolate through the
alkali residuum, and after this percolation through one vessel are conducted to
other vessels arranged in the same manner. In purifying coal gas it is
customary to conduct this gas through a series of vessels. containing lime,
gases

page_text: which has been previously used for the same purpose, and which is impreg-
nated in different degrees with the impurities thereby abstracted, and to
provide that in passing through the last vessel the gas shall be in contact with
lime almost or altogether devoid of such impregnation. In the like manner I
arrange the apparatus containing alkali residuum, so that the mixed gases shall
pass through several vessels containing residuum which has been previously
employed for the like purpose, and acted upon in different degrees, and so
that the gases in passing through the last of such vessels shall percolate
through residuum which is either quite fresh, or but little acted upon by its
previous exposure to such gases. I thus attract from the mixed gases the
whole or the greater part of the carbonic acid gas, and obtain an increased
quantity of sulphuretted hydrogen, and the gas which remains is rendered
more suitable for combustion. It is proper to observe, that the alkali
esid uum must contain some water when exposed to the action of the mixed
gases, because if it were perfectly dry the carbonic acid gas would not react
on the sulphuret of calcium. Instead of obtaining sulphuretted hydrogen from
alkali residuum by means of muriatic acid, I sometimes used carbonic acid
gas as the agent for effecting reaction on the sulphuret of calcium, and thereby
obtaining sulphuretted hydrogen, and for this purpose I employ such an
apparatus as I have described for the application of the mixed gases to the
alkali residuum, and I effect the operation in the same manner as I have
herein-before described for such mixed gases. The gas obtained from alkali
residuum by the processes herein-before. indicated may at once be used, but I
prefer to collect it in a gasometer before I use it, and when I apply it to the
manufacture of sulphuric acid I transfer it through tubes to a suitable appa-
ratus, wherein I cause it to undergo combustion. This combustion may be
effected by means of burners, similar to those used for burning coal gas, and
the operation being conducted in an oven or furnace connected with a suitable
apparatus, the sulphurous acid produced may be converted into sulphuric
acid in the usual manner. The action of carbonic acid on sulphuret of
calcium contained in alkali residuum, as herein-before described, occasions the
production of a quantity of carbonate of lime, in addition to that previously
contained in the residuum; and I use the carbonate of lime which I obtain
from the residuum for purposes connected with the manufacture of alkali
instead of native carbonate of lime.
I do not confine myself to the use of the apparatus herein-before described
for effecting the object of that part of my Invention which relates to the use
of the alkali residuum, inasmuch as other apparatus may be employed for
such purpose; nor do I claim any privilege with respect to the use of such

page_text: apparatus. As to the whole I claim as my Invention the preparation (for the
purpose herein mentioned) of the said artificial oxide of manganese from pre-
cipitated protoxide of manganese, by causing this protoxide, whilst in the state
of hydrate, to be agitated in contact with atmospherical air, so as to absorb
oxygen therefrom, & the use of the oxide so prepared for the purpose of pro-
ducing chlorine by means of muriatic acid obtained by the decomposition of
common salt, and the use of alkali residuum for obtaining therefrom sulphu-
retted hydrogen by means of muriatic acid or carbonic acid, or the combined
use of these two acids acting on the alkali residuum, and also the use of
alkali residuum for obtaining therefrom carbonate of lime to be used in, the
manufacture of alkali..
In witness whereof, I, the said William Gossage, have hereunto set my
hand and seal, this Seventeenth day of February, in the year of our
Lord One thousand sinkt hund