IMPROVEMENTS IN THE MEANS AND APPARATUS POR MANUFACTURING ALKALI, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO OTHER PURPOSES
Year: 1875

page_text: LETTERS PATENT to William Alexander Lyttle, of The Grove,
Hammersmith, in the County of Middlesex, Civil Engineer, for
the Invention of "IMPROVEMENTS IN THE MEANS AND APPARATUS POR
MANUFACTURING ALKALI, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO
OTHER PURPOSES."
Sealed the 13th August 1875, and dated the 20th February 1875.
PROVISIONAL SPECIFICATION left by the said William Alexander
Lyttle at the Office of the Commissioners of Patents, with his
Petition, on the 20th February 1875.
I, WILLIAM ALEXANDER, of The Grove, Hammersmith, in the County
of Middlesex, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MEANS AND APPARATUS FOR MANU-
"FACTURING ALKALI, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO OTHER PUR-
POSES," to be as follows:-
-
This process consists in the manufacture of oxide of sodium by means
of a smelting or reducing process in a peculiar blast furnace, such oxide
being produced either directly by the reduction of sulphate of sodium to

page_text: the required oxide, or indirectly by the two following modifications of
the same smelting or rather reducing process. The same process applies
equally in all respects to the manufacture of oxide of potassium.
A. To reduce the sulphate of sodium to sulphide of sodium by the
aforesaid smelting process, and then reduce such sulphide by igniting or 5
boiling it with the oxide of any metal having a stronger affinity than
sodium for the sulphur combined with the latter.
B. To produce protoxide of barium by either of the foregoing direct or
indirect methods prescribed for making oxide of sodium, and use it as the
means in the hydrated caustic or carbonated state for precipitating the 1
sulphuric acid from sulphate of soda, thus producing in solution in the
precipitating tank either caustic or carbonated soda in a perfectly pure
state ready for the market as caustic soda.
The smelting process by which the aforesaid reduction is effected is
conducted in precisely the same way and with the same apparatus as I
have described for the production of iron and steel in the Specification of
my Letters Patent, numbered 2984, of last year, entitled "Improvements
in the Manufacture of Iron and Steel," the only difference being in the
materials employed, sulphate of sodium or sulphate of barium being
substituted wholly or partly for the iron ore. The mixed materials in a
powdered state must be made into lumps as described in the aforesaid
iron and steel process, and the mode of applying the requisite reducing
heat is in all respects the same.
In carrying out the direct method of making the oxides of sodium and
barium the desired result is effected by making the lumps with a
powdered and a thoroughly incorporated mixture of sulphate of sodium
or barium, ferric oxide or iron ore, and carbonaceous matter; the con-
solidation of this mixture into firmly coherent lumps being effected by
means of clay, or raw plastic peat, or peat and clay together. The
proportion of ferric oxide employed in any form must be fully sufficient
to combine with and remove the whole of the sulphur present in the
sulphate, and the fixed carbon of the carbonaceous matter should be
sufficient in conjunction with the carbonic oxide of the flame to reduce
the ferric oxide to the metallic state.
Powdered metallic iron or copper reduced in the same way may first
be produced by means of the aforesaid iron and steel process, and by
incorporating it with well calcined sulphate of sodium and carbon in a

page_text: powdered state, and then smelting it in the same manner after con-
solidation into lumps in the aforesaid way, the same direct manufacture
of the oxides of sodium or barium may be effected. The proportions of
iron or copper and carbon employed must be gauged so as to be slightly
5 more than equivalent to the proportions of sulphur and oxygen which
these reducing agents are expected to remove from the compounded
mass of each lump. The indirect process is similar with this difference
only as regards the smelting, that ferric oxide or iron ore are omitted,
and the reduction of the sulphate to sulphide of sodium or barium is
effected by the incorporated carbon, aided by the carbonic oxide gas of
the flame.
These sulphides may be reduced to oxides by calcination or boiling in
water, with equivalent proportions of the oxides of copper, zinc, or any
other metal having a greater affinity for the sulphur of the sulphides
than that possessed by the sodium or barium under such conditions of
treatment.
When oxide of sodium or barium is produced by the foregoing direct
process, such oxides are separated in a pure state as hydrates by
lixiviation and filtration with water in any desired way. Under both
the direct and indirect processes the sulphur will be fixed by transfer to
metals, from which it can easily be recovered for the manufacture of
sulphuric acid in the manner herein-after described, or in the present
well known way of making that acid from pyrites..
In order the more economically to recover the sulphur from the ferric
sulphide produced under the before-mentioned process, and to combine
such recovery of the sulphur with the simultaneous production of
sulphate of sodium, I thoroughly mix the ferric sulphide with sodic
chloride and clay, and work the mixture into lumps in the same way as
I have herein-before described in dealing with the reduction of the
sulphates. Any relative proportions of ferric sulphide and sodic chloride
which may be found most convenient in practice can be employed, but
economy will be best consulted by having rather more sodic chloride
than will be needed in order to form sulphate of sodium with all the
sulphur of the ferric sulphide, assuming that all such sulphur should be
converted into sulphuric acid by the following treatment:-The clay
employed need not be more than will just suffice to give solidity to the
mass. The consolidated lumps of ferric sulphide, sodic chloride, and
clay, which I shall designate salt lumps, should then be charged into my

page_text: reducing iron and steel furnace, as herein-before mentioned, but the
flame employed should be of the most highly oxidizing character by
having enough free oxygen and ordinary or superheated steam injected
therewith into the furnace to fully oxidate the iron of the ferric
sulphide, and convert the liberated sulphurous acid gas into sulphuric
acid; the latter will then decompose the sodic chloride forming the
required sulphate of sodium, and setting free hydrochloric acid which
can be arrested in the usual way; in fact the free air entering the
furnace must be sufficient in quantity to calcine or roast the ferric.
sulphide, and as this is taking place the nascent sulphurous acid should
also meet with enough free oxygen and watery vapour to enable it to.
pass into sulphuric acid. The lumps of material thus treated can be
crushed on removal from the bottom of the furnace, no cooling being
needed below such bottom, and the crushed mixture can either be freed
of the clay by lixiviation with water, leaving the sulphate of sodium in
solution, or the crushed lumps may at once be incorporated with
carbonaceous matter with or without a further supply of ferric oxide for
reduction of the sulphate of sodium as already herein-before described.
Natural iron pyrites may also be mixed with chloride of sodium, and
treated in the foregoing way in order to produce therefrom sulphate of
sodium for any purpose in trade or manufacture.
Protoxide or sulphide of barium made as herein-before described is also
available for any other purpose in chemical technology where such
agents are now used.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 25
filed by the said William Alexander Lyttle in the Great Seal
Patent Office on the 13th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ALEXANDER LYTTLE, of The Grove, Hammersmith, in the County of
Middlesex, Civil Engineer, and Fellow of the Chemical Society, send 30
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of February, in the
year of our Lord One thousand cight hundred and seventy-five, in

page_text: the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said William Alexander.
Lyttle, Her special license that I, the said William Alexander Lyttle,.
my executors, administrators, and assigns, or such others as I, the said
William Alexander Lyttle, 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 "IMPROVEMENTS IN THE MEANS AND APPARATUS
FOR MANUFACTURING ALKALI, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO
OTHER PURPOSES," upon the condition (amongst others) that I, the said
William Alexander Lyttle, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be 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 Alexander Lyttle, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained.
in and by the following statement thereof, that is to say:
-
The process consists primarily of a new method for effecting the
deoxidation of the sulphates of sodium, potassium, and barium, and their
conversion thereby into sulphides upon precisely the same principles.
of reduction in a vertical blast furnace, as are laid down for the pro-
duction of iron, steel, and other metals by reduction without fusion, in
the Specification of my Letters Patent, numbered 105, entitled "Im-
provements in the Means and Apparatus for Producing or Manufacturing
Iron, Steel, and other Metals," and dated 12th January 1875. The only
essential difference between the last-mentioned metallurgical process,"
and that which I am now about to describe lies in the character of the
result, which is in the former case a metal, whilst in the latter the
immediate product of the reducing furnace is a sulphide of the required
alkaline metal or of barium. Sulphate of calcium and all other
metallic sulphates can be reduced to sulphides cheaply in the same
manner. Baric sulphide thus cheaply produced can then be converted

page_text: easily into oxide by any of the well known methods already in use for
that purpose, and the process thus furnishes the most economical means
of producing caustic alkali direct from sulphate of sodium or "salt
cake." The production by this method of cheap oxide of barium
presents a new facility of great value to the chemical technologist, for
the ready and economical removal of sulphuric acid from its various
combinations, and in this direction the process now described is
applicable to other purposes as well as the production of alkali.
In order to effect the deoxidation of any of the above-mentioned or
other metallic sulphates without removal of the sulphur, that salt is
finely crushed and mixed with carbonaceous matter and pugged into lumps
with clay or any of the other consolidating materials described in my
aforesaid Specification of my Letters Patent numbered 105. These
compounded lumps are subjected to the action of a reducing or a merely
non-oxidizing flame in a reducing furnace, as described in reference to
Figure 4 of the aforesaid Specification. In this case the product of the
reducing furnace is the sulphide of barium or of the other metal, the
sulphate of which is so treated, and this sulphide can be reduced to the
required oxide by boiling it or igniting it in one of the many well known
ways with the oxide of a metal which has a stronger affinity for sulphur
than that possessed by barium or the other metal the sulphide of which
is under treatment.
The sulphide of barium can also be converted into carbonate by
passing through its solution a current of carbonic anhydride, and this
carbonate of baryta can be reduced to protoxide of barium by mixing it
with carbonate of lime in the well known way, and calcining it at a
strong heat in a current of steam. By mixing the powdered baric
sulphide with ferric oxide and clay, or instead of clay with any of the
other consolidating ingredients mentioned in the Specification of the
aforesaid Patent, No. 105, and then subjecting the lumps of this com-
pound to the flame of the vertical blast furnace the desired effect is
produced, because the iron gives its oxygen to the barium and takes in
exchange the sulphur to form a sulphide of iron. The same plan applies
to the conversion of sulphides of alkaline metals to oxides, but with this
drawback, when clay is employed as the consolidating material for
making the mixture into lumps, that the resulting caustic alkali com-
bines with the silica and alumina of the clay to form soluble salts.
These salts can however be decomposed by passing through their

page_text: solution a current of carbonic anhydride, thus yielding the alkali as a
pure carbonate.
When hydrate of baryta is produced by the above process it will only
be necessary to add it with water to sodic or potassic sulphate in
suitable or equivalent proportion in order to convert the whole of the
sulphate into solution of pure caustic alkali with baric sulphate as a
precipitate. This precipitated baric sulphate is in the best possible
molecular condition for being most readily and economically reduced
again to sulphide, as herein-before described.