AN IMPROVED PROCESS AND APPARATUS FOR REDUCING ALKALINE AND EARTHY SULPHATES AND CHLORIDES TO THEIR ELEMENTS
Year: 1879

page_text: LETTERS PATENT to Henry Edward Newton, of the Office for Patents, 66,
Chancery Lane, in the County of Middlesex, Civil Engineer, for the Invention
of "AN IMPROVED PROCESS AND APPARATUS FOR REDUCING ALKALINE AND
EARTHY SULPHATES AND CHLORIDES TO THEIR ELEMENTS." A communication
from abroad by Ernest Amand Gaston Bong, of Paris, in the Republic of
France
Sealed the 2nd September 1879, and dated the 6th March 1879.
PROVISIONAL SPECIFICATION left by the said Henry Edward Newton at
the Office of the Commissioners of Patents on the 6th March 1879.
HENRY EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer. "AN IMPROVED PROCESS AND APPARATUS FOR
REDUCING ALKALINE AND EARTHY SULPHATES AND CHLORIDES TO THEIR ELEMENTS.”
[A communication from abroad by Ernest Amand Gaston Bong, of Paris, in the
Republic of France.]
This improved process has for its principal object to treat the sulphates of potash,
soda, lime, baryta, and strontia, in such a manner as to transform them into
carbonates, and incidentally the sulphates of magnesia and alumina, so as to convert.
them into oxides; the sulphur may be extracted in the state of sulphur or of
sulphurous acid, the improved process also admitting of (at one operation) converting
the alkaline chlorides into carbonates and hydro-chloric acid.
The principle of the process is to reduce the alkaline sulphates, the sulphates of
baryta, lime, and strontia, by sulphuretted hydrogen, and to produce this sulphuretted
hydrogen by the decomposition in any suitable manner by means of carbonic acid
of the sulphur obtained in the process.
The quantity of sulphuretted hydrogen obtained being insufficient to completely
reduce the sulphate there should be added a certain quantity of reducing gases
obtained from a gas generator, and containing as much as possible of the hydrogen,
so as not to introduce too great a quantity of inert gases into the sulphuretted
bydrogen. These reducing gases may be sent into the oven or apparatus either at
the same time as the carbonic acid or at any other suitable time. The reducing

page_text: gases moreover by their oxidation will produce the carbonic acid, which decomposes
a portion of the sulphur and engenders a certain quantity of carbonate.
When it is only required to treat sulphates the reducing substance may be carbon,
such as anthracite or coke, which may be mixed with the sulphate and made up
into bricks. In such cases the combustible will be burned by means of the oxygen
contained in the sulphates, thereby producing heat exactly at the place where it is
required; moreover the sulphurous gas obtained is not diluted with a quantity of
atmospheric nitrogen which would uselessly take up or absorb the heat.
If it be required to extract from the sulphates the sulphur and not the sulphurous
acid it would only be necessary to carry out (from the apparatus at convenient
points) the sulphuretted hydrogen and the sulphurous acid, and to mix them in a
heated state. By extracting the gases at certain parts of the apparatus a large
quantity of sulphur completely formed may be collected. By suitably regulating
the temperature in the chambers a large quantity of sulphur in a free state may be
collected from the final solid product.
If it be desired simply to produce sulphurets, the addition of carbonic acid must
· be avoided and foreign reducing agents employed exclusively. For treating
sulphates they are first mixed with foreign substances, and then heated by means
of any waste heat, or by heat obtained from furnaces employed for the purpose.
The sulphuretted hydrogen and reducing gases which act upon them oxydize with
the disengagement of heat which keeps up the required temperature. The sulphates
are thus converted into sulphurets, and even into carbonates, the carbonic acid
which acts on the sulphurets is then absorbed and disengages sulphuretted hydrogen,
and for this reason the gases which will finally act will become very reducing. As
regards the chlorides they may also be converted into carbonates by passing through
the intermediate state of sulphate which is effected by any suitable process. By
making use of the process for producing the alkaline sulphates (by the action of
corresponding chlorides upon the sulphates of alumnia or magnesia) there will be left
after wasting a residue of alumnia or magnesia.
The operations constituting the improved process may be carried on most con-
veniently in an apparatus specially designed for the purpose, and divided into
several separate compartments arranged so that they may be placed in communi-
cation with a space or reservoir intended to contain the gases which are to be
.employed in the process. To this end there are a number of openings arranged in
this reservoir, each of which communicates with a closed chamber. At the lower
part of each compartment are a series of small domes which communicate with each
other, and with the exit opening. The solid mass of the substance under treatment
is heaped up against these domes, and therefore the extent of surface from which
the gases may be drawn off is considerable. The gases on leaving the compartment
enter a vertical flue which is divided into two branches, and is provided with regu-
lators. By means of these devices the gases, smoke, and volatile matters may be
drawn off. The compartments are filled through openings at the upper part, and
they are provided with doors at the lower part, whereby the contents may be stirred
and withdrawn when required. The compartments are each also provided with a
fireplace for generating heat and gases which are conducted up a chimney to the
upper part of the compartment, where they escape and spread out in the compart-
ment. In order to supply hydrogen to the apparatus water in a finely divided
state or in a state of vapor is injected or it may be thrown onto incandescent carbon,
but the hydrogen may be obtained in any other manner. The carbonic acid gas
required in the process may also be obtained from any convenient source.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Edward Newton in the Great Seal Patent Office on the 5th
September 1879.
HENRY EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer. "AN IMPROVED PROCESS AND APPARATUS FOR
REDUCING ALKALINE AND EARTHY SULPHATES AND CHLORIDES TO THEIR ELEMENTS."
A communication from abroad by Ernest Amand Gaston Bong, of Paris, in the
Republic of France.
This process has for its object so to treat sulphates of potash, soda, lime, baryta,
and strontia, as to transform them into carbonates, and incidentally to treat sulphates
of magnesia and alumina so as to transform them into oxides; the sulphur may be
extracted either in its pure state or as sulphurous acid, this process also admits at
one operation of transforming alkaline chlorides into carbonates and hydrochloric
acid (acide chlorydrique).
The principle of the process is to reduce alkaline sulphates, sulphates of baryta, of
lime, and of strontia, by sulphuretted hydrogen, and to produce this sulphuretted
hydrogen by the decomposition of the sulphuret itself obtained in this reduction in
all the known conditions by means of carbonic acid. All these reactions are effected
without causing the fusion of the matter under treatment.
•
The quantity of sulphuretted hydrogen being insufficient to completely reduce
the sulphate I add a certain quantity of reducing gases which will be produced in a
generator.
These reducing gases by their oxydation will further produce carbonic acid,
which will immediately decompose with heat a portion of the sulphuret, and will
directly engender, so to speak, a certain quantity of carbonate.
By employing not too reducing and suitable gaseous mixtures containing oxide of
carbon and hydrogen, an excess of carbonic acid, and a small quantity of steam, it
will happen that the sulphuret will be carbonized as it is made, and carbonates will
thus be almost immediately produced.
By this means the necessity would be avoided of passing by the intermediary of
a mass rich in sulphur, the fusion of which in the case of alkaline salts might be
feared.
When it is desired only to treat sulphates the quantity of reducing gas employed
may be diminished, and a small quantity of coal (preferably anthracite) should
previously to treatment be mixed with the sulphate.
In any case the combustible will be burned by the oxygen contained in the
sulphates, and heat will consequently be developed at those points where it is most
necessary; in addition, the sulphurous gas obtained will not be diluted by quantities
of atmospheric air, which furthermore would uselessly absorb the heat.
If it is desired to obtain from the sulphates sulphur in place of sulphurous acid it
will only be necessary to augment the reducing dose. Sulphuretted hydrogen and
sulphurous acid may also be caused to leave the furnace at suitable points, and may
be mixed together preferably with heat; it is even possible as the gases are with-
drawn from certain parts of the furnace to collect a large quantity of free sulphur.
By regulating judiciously the temperature in the chambers, that is to say, by pro-
ducing the carbonization (carbonation) at a temperature inferior to that of the
volatilization of the sulphur it would be also possible to find a large quantity of
free sulphur in the solid final product the result of the decomposition of the
polysulphurets.
If it is desired to produce simply sulphurets it will suffice to prevent the formation
of carbonic acid, and to employ exclusively foreign reducing agents, such as hydrogen
or carbonic oxide or coal, but by their mixture.
Finally in order to treat the sulphates they must be warmed first by waste heat
or by direct furnace heat after they have been mixed (if this be necessary) with

page_text: foreign substances; the sulphuretted hydrogen and the reducing gases which act
upon the sulphates become oxydized with a disengagement of heat which maintains
the desired temperature. The sulphates are thus transformed into sulphurets, and
even to a great extent into carbonates; the carbonic acid which acts upon the
sulphuret is then absorbed in disengaging the sulphuretted hydrogen.
Under parallel conditions sulphates of alumina and alums give oxydes instead of
carbonates; they may be obtained free from iron by being washed in weak acid, for
the oxide of iron which might discolor them is reduced during the operation and
becomes soluble in the acid.
Alkaline and earthy sulphates may if desired be mixed together so as to avoid in
certain cases the fusion of the one, and the too great lightness of the product given
by the others; more especially of alumina.
With regard to chlorides they may also be transformed into carbonates by passing
them through the intermediate stage of sulphates. This transformation of the
chlorides into sulphates may be effected by any of the known processes.
When producing alkaline sulphates by the action of the corresponding chlorides
on sulphates of alumina or magnesia a residue will be obtained after washing of
alumina or magnesia; thèse oxides having been submitted to the action of the
reducing gases contain iron which discolors them and which is generally in a
metallic form or as a sulphuret. By washing with a weak acid the iron will be
dissolved, and the oxydes will be eventually obtained in a pure state: In order
thus to reduce the iron the gases should be of a very reducing nature.
These operations are conducted, by preference, in an apparatus containing a series
of chambers or ovens, and which constitutes an important part of the present
Invention, and will be presently described with reference to the accompanying
Drawing.
By the use of this apparatus transformations still more complete of the element
of the sulphates may be effected, by adapting a furnace to each chamber or oven;
for instance, the carbonate resulting from the decomposition of sulphate of lime may
be converted into lime, and by not arresting this decomposition rendered hydraulic
by the presence of a certain quantity of nondecomposed sulphate may be obtained.
Sulphates previously mixed with silica, alumina, or clay, and treated as above
described, may thus be transformed into silicates, aluminates, or cements.
Fig. 1 is an irregular longitudinal section of the apparatus taken on the line C, D,
of Fig. 2, which is a plan view partly in section taken on the line A, B, of Fig. 1.
Figures 3 and 4 aro transverse sections taken on the lines E, F, and G, H,
respectively, of Fig. 2. The chambers A, A, are two rows of chambers or ovens set
back to back which may be of any suitable form. Each chamber A has at its upper
part a number of openings B through which the chamber is charged, and at its
lower part a door C through which the contents of the chambers may be stirred
from time to time or withdrawn when required.
Between the two rows of chambers or ovens A and extending from end to end
thereof is a narrow chamber D. This chamber (which is formed in part by the
back walls of the ovens A) serves as a reservoir for the reducing gases. In the roof
of this chamber D is a series of openings E, which communicate with small chambers
Fabove the chambers D. These chambers F are severally in communication by
means of passages G with one oven in each of the rows or series, and serve to
conduct the reducing gases from the reservoir D to the ovens A.
On the bottoms of the ovens or chambers A are formed open
arched passages
which communicate with each other and with the exit opening I.
The solid mass of the substance under treatment is heaped up on these arched
passages, the result being that the extent of surface from which the gases may be
drawn off is greater than if the substances were lying on a flat surface.
H
The gas on passing through the exit passage I of one chamber rises up a vertical
passage J, and thence passes off by one or other of two branch passages K and L.
By the passage K it is led into the next adjacent chamber A with the upper part of
which that passage communicates. The passage L opens into a transverse exit

page_text: passage M provided with a regulator N, and from which the gases produced, such as
sulphurous acid or hydrochloric acid gas and the smoke are gathered by the special
passages or vent holes X, T, W.
By means of the regulator O which serves to close the passage K the communi-
cation between one chamber and another may be cut off." Sight holes P, Z, are
provided in each chamber A
The chambers or ovens A may each be provided with a furnace Q by which they
can be heated when desired. The furnace is surmounted by a chimney R which
carries the heated gases to the upper part of the chamber, from whence they
descend, distributing themselves through the whole mass under treatment.
If desired these heated gases may be caused to pass successively through two or
three chambers until they become cold.
•
The chimney R has openings at various heights by which the heating can be
regulated, and the number and position of these chimneys may be varied according
to circumstances.
The reducing gases issuing from the gas generators are impregnated with hydrogen
in any convenient manner, care however being taken that the reducing gases so
treated are free from azote.
The excess of carbonic acid which the reducing gases should generally contain
may be obtained in any convenient manner, but preferably by injecting steam into
the reducing gases.
The movement of the gas may be caused by a blower or injections of steam. In
the latter case a slight but uniform pressure may be maintained in the apparatus,
and thereby escapes of gas or the entrance of air will be avoided.
The reservoir D placed between the rows of chambers or ovens A will render the
composition and the temperature of these gases more regular. This reservoir is
closed at its extremities by thin plates which having only slight resisting force will
act as safety valves.
This apparatus will also serve for carrying out the well known process for the
conversion of chlorides into sulphates.
Having now described this Invention as communicated to me by my foreign
correspondent, and having explained the manner of carrying the same into effect, I
wish it to be understood that under the above in part recited Letters Patent I
claim,―
First. The process as herein described of transforming alkaline sulphates, the
sulphates of baryta, strontia, and lime, or sulphates produced in the apparatus itself
by means of the chlorides of these substances, the said sulphates being converted on
the one hand into carbonates, and on the other hand into sulphur or sulphurous
acid, their reduction being effected by means of the sulphuretted hydrogen obtained
from the decomposition of the sulphurets produced, the action of this gas being
assisted by suitable reducing gases which will effect the conversion into carbonates
of the materials under treatment during the reducing process.
Second. The production as accessory products of pure alumina and magnesia as
above described.
Third. The arrangement of apparatus shewn in the Drawings, whereby the
process of reducing alkaline and earthy sulphates and chlorides to their elements
may be effected as above described.
In witness whereof, I, the said Henry Edward Newton, have hereunto set
my hand and seal, the Fifth day of September, in the year of our Lord
One thousand eight hundred and seventy nine.
H. E. NEWTON. (L.S.)