Improvements relating to the Manufacture of the Aluminates, Sulphates, and Carbonates of Soda and Potash, and to the Production or Recovery of Alumina and other Bye-products.
Year: 1891

page_text: Date of Application, 10th Mar., 1891
Complete Specification Left, 10th Dec., 1891-Accepted, 10th Mar., 1892
PROVISIONAL SPECIFICATION.
Improvements relating to the Manufacture of the Aluminates,
Sulphates, and Carbonates of Soda and Potash, and to the
Production or Recovery of Alumina and other Bye-products.
.
1, CARL FRIEDRICH CLAUS, of 88 Yeldham Road, Hammersmith, in the
County of Middlesex, Chemist, do hereby declare the nature of this invention to be
as follows:-
My invention relates to the manufacture of the aluminates, sulphates and
carbonates of soda and potash, and to the production or recovery of alumina and
other bye-products.
In manufacturing aluminate of soda or of potash according to my said invention,
I proceed as follows, riz. :-I first mix alumina, bauxite or similar minerals, or
hydrate of alumina as produced or recovered in the process hereinafter described,
with sulphate of soda or sulphate of potash in approximately equal proportions; a
slight excess of alumina is, however, not detrimental. I heat this mixture in an
atmosphere of, or by hot hydrogen, water-gas or carbonic oxide. To the said
mixture, carbonaceous material may or may not be added. The heating of the said
mixture, with or without the addition of carbon, may be effected in retorts, muffle-
furnaces, revolving black ash furnaces, or other suitable apparatus. The most
suitable mode of heating for my process, is in kilns or brick-chambers like
continuous-working brick-kilns, though structures like continuous working lime-
kilns may also be used. The mixture to be heated, I prefer to mould into pieces
such as bricks or balls, before charging it into the heating apparatus, such bricks
being preferably perforated, so as to present a large surface to the action of the
gases. The heating of the mixture may be effected, at the commencement of the
process, by any ordinary method by bringing the products of combustion of solid or
gaseous fuel into direct contact with the moulded mixture. But, when the charge
has been heated in this manner to the temperature at which hydrogen, water-gas or
carbonic oxide or generator-gas will decompose the mixture, the heating by the
ordinary mode of firing must be discontinued, and hydrogen, water-gas, carbonic
oxide or generator-gas at a temperature at which the same will decompose the
mixture, must then be admitted into the charge and passed through the same until
the decomposition of the mixture is completed. This temperature varies according
to the kind of gas admitted into the charge, carbonic oxide requiring to be of a
higher temperature than either water-gas or hydrogen-gas in order to have the
same effect. Either of the gases, however, effect the decomposition much more
rapidly and at a much lower temperature than is practicable by the ordinary mode
of producing aluminate of soda. Water-gas at the temperature at which it leaves
the "producer" is suitable for the purpose of effecting the decomposition at a low
temperature; generator-gas made with or without the aid of steam can also be used.
To complete the decomposition of a charge of the said mixture, an excess of the
gases has to be used and, towards the end of an operation, when the decomposition
of the charge is nearly completed, a large quantity of the gas or gases would pass
out of the heating apparatus unused.
To provide for the utilization of these gases in my process, I employ a number
or series of furnaces, kilns or other heating apparatus, and I pass the gas from the
one charged first into the one charged next, and so on, until such gas leaves the one
charged last, as nearly as is practical, deprived of hydrogen, or carbonic oxide or
both, and converted into water or carbonic acid or both as the case may be.
Instead of kilns, high shaft furnaces may be employed for this purpose, the fresh
charges being placed on the top and the finished charges withdrawn from the
bottom, in a similar manner to the working of a lime-kiln in which the hot gases

page_text: are admitted at the bottom and the residual gases withdrawn from the top.
I prefer, however, to extend the long length of charges in a horizontal direction by
using a number or series of kilns as above described. When the decomposition of
the first charge is completed, the gas, riz.-hydrogen water-gas, or carbonic oxide
with or without steam, is shut off from the kiln containing it and turned into the
kiln or furnace charged next, and, when the decomposition in this furnace is
completed, into the next to it, and so forth through the whole of them. The
finished charge in the first kiln is now cooled by cold gases or cold air, and the heat
thus imparted to such gases or air may be utilised in the process. When the charge
is cool enough to be removed, the kiln or furnace is recharged with fresh material
and becomes now the last in the series.
If the heat inherent in the gases is not sufficient to effect the decomposition,
external heat should be applied in any convenient manner.
In heating the mixture of alumina, bauxite or hydrate of alumina as above stated,
in the presence of or by the hot gases above referred to, in the aforesaid furnaces or
kilns, sulphide of hydrogen is formed by the action of the said gases upon the
mixture. If the alumina is used in the form of hydrate which parts only with its
water of hydration at an elevated temperature, or if the gases employed contain
hydrogen or vapours of water, then sulphide of hydrogen is principally produced.
As above mentioned, the effluent gases from the first charged kiln are made to
pass into the next charged kiln, and so forth through the whole series, and thus the
sulphide of hydrogen discharged from the first charged kiln passes into the next,
more sulphide of hydrogen is there produced (by the decomposition of the mixture
therein) and this again passes to the next and so forth.
By the action of the carbonic-oxide on the charges of mixture in the series of
kilns, it becomes converted into carbonic acid. The sulphide of hydrogen produced
as above described and the carbonic acid pass out together from the last kiln. By
adding sufficient air to this sulphide of hydrogen, sulphurous acid may be produced,
and such sulphurous acid may then be made use of for converting chloride of
sodium or of potassium into sulphates by the process known as Hargreaves' process,
by adding steam and atmospheric air to these gases and passing them through these
chlorides as is well known.
I prefer to use hydrogen or water-gas for acting upon the mixture of alumina
and sulphates. In this case, sulphide of hydrogen is formed principally and one of
two methods may be adopted, cis. :-According to one method, sulphur may be
recovered from the same in the free state by admitting either cold or hot air into
one of the kilns situated between the first and the last charged kilns, in sufficient
quantities to form water with the hydrogen of the sulphide of hydrogen, whereby
free sulphur is formed which may be recovered as such by collecting it in suitable
chambers. In this case, however, as is obvious, it is no longer available for
converting the chlorides above mentioned into sulphates, and further quantities of
sulphurous acid required in the process will have to be supplied from other sources
as for instance by burning pyrites.
If it is not desired to recover the sulphur from the sulphide of hydrogen, then,
according to another method, a sufficient quantity of cold or hot air is admitted into
one or more of the kilns between the first and the last, to burn all the sulphide of
hydrogen into sulphurous acid.
Such sulphurous acid I use for converting alkaline chlorides into sulphates and
this is carried out in a series of kilns. All of these kilns I charge on starting the
process, with the alkaline sulphates mixed with the alumina. The sulphurous acid
formed by the combustion of the sulphide of hydrogen produced in the first few
kilus by means of air admitted into intermediate kilns, will be arrested in its
progress through the remainder of the kilns to form alkaline sulphates, so that, for
a time, no sulphurous acid will pass out of the last kiln of the series. It will be
retained and stored up and the kilns will be stocked with sulphurous acid in the
form of sulphates. The admission of hydrogen, water-gas or carbonic oxide into
the first kiln, or of sulphurous acid into the intermediate, kilns respectively, should

page_text: be such that no sulphurous acid passes away out of the last charged kiln. I now
begin to charge into the kiln (which has to be supplied with a fresh charge and
which has thus become the last in the series), a mixture not of alkaline sulphate,
but of the alkaline chlorides and alumina or hydrate of alumina. The alumina of
this mixture acts as a carrier for the sulphuric acid and will decompose the alkaline.
chlorides as soon as sufficient heat reaches the mixture, and will liberate hydro-
chloric acid. By using a sufficient number of kilus and regulating the supply of
hydrogen, water-gas or carbonic oxide (with or without steam) to the first charged
kiln, I am able to obtain aluminate of soda or of potash in the first charged kiln,
and to draw hydrochloric acid gas from the last one. In the course through the
kilns, the sulphide of hydrogen or the sulphurous acid travels in the direction from
the first towards the last, and the reaction upon the alkaline sulphates travels in
the direction from the last towards the first kiln, in which such sulphates are
decomposed, the gases from the last, of course being mixed with the exhausted and
used up other gases resulting from the action of the sulphates of the alkalies upon
the hydrogen, or water-gas or carbonic oxide.
Obviously, in as far as there may be a loss in the process of the sulphur originally
introduced into it, such loss will have to be made good by the introduction of
further quantities of sulphate into the circulation. Such loss may take place by
undecomposed sulphate being carried away in the finished aluminate, or by passing
away with the hydrochloric acid and other gases from the last kiln, but the
remainder of the sulphur will remain in the series of kilns and will do duty again
and again for decomposing chlorides.
No sulphur will pass out of the process, though it is constantly used therein.
But if sulphur is to be recovered as such sulphurous acid from pyrites together with
air and steam is introduced into some of the intermediate kilns.
The finished charges of aluminate of soda or of potash, I decompose by means of
carbonic acid; the gases from a line-kiln.or other products of combustion may be
used for this purpose; and the decomposition may be carried on in the first kiln
after it has been disconnected from the rest of the kilns, by passing these gases
together with steam through the charge, and afterwards lixiviating it and separating
thus the carbonate of soda or of potash from the hydrate of alumina. Or the
finished charge may be dissolved in water in any suitable manner; and carbonie
acid from any available source may be forced through the solution. The solution
of carbonate of soda or of potash is then treated in a well known manner for the
manufacture of the soda or potash of commerce.
The hydrate of alumina obtained by this operation may be used or sold, or it
may again be mixed with alkaline sulphate or chlorides to serve in this process
again and again in the one form or the other. If the alumina is sold and not used
again, its place is filled by a fresh quantity of bauxite or like mineral.
The hydrochloric acid evolved in the process is condensed in the usual manner
and used for any well known purpose.
. 1001
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of the Aluminates,
Sulphates, and Carbonates of Soda and Potash, and to the
Production or Recovery of Alumina and other Bye-products.
I, CARL FRIEDRICH CLAUS, of 88, Yeldham Road, Hammersmith, London,
Chemist, do hereby declare the nature of this invention and in what manner the
the
same is to be performed, to be particularly described and ascertained in and by
following statement :-
The primary object of this invention is the manufacture of carbonate of potash or

page_text: of soda by the intervention of the sulphates and aluminates of potash and of soda
between the chlorides of these alkalies and their carbonates; and further the
manufacture of pure hydrate of alumina and of hydrochloric acid.
As a secondary object may be considered the production of the aluminates of
potash and of soda and the recovery of sulphur used in the process. The recovery
of the sulphur in or by the process may, however, be considered optional, that is to
say, the sulphur used in the same may either (1) be continually used again and
again for the purpose of carrying out the process, or it may (2) be obtained in the
form of pure sulphur as a bye-product. In the second case, all the sulphur required
for the purpose of carrying out the manufacture of sulphate, aluminate and carbonate
of potash or of soda will have to be supplied from external sources, as for instance
from the burning or roasting of pyrites or other suitable sulphurous ores.
In starting the process when the first of these methods is to be adopted, I first
of all intimately mix ground hydrate of alumina, such as bauxite or minerals of a
similar composition, or the hydrate of alumina recovered in a subsequent part of my
process, with sulphate of potash or of soda, I then heat the mixture in direct con-
tact in an atmosphere of hot or heated hydrogen, water-gas or carbonic oxide,
whereby aluminate of potash or of soda is formed, whilst sulphide of hydrogen gas
is liberated.
The sulphide of hydrogen so produced I mix with a suitable quantity of air, and
I ignite the mixture and burn the sulphide of hydrogen to sulphurous acid and
steam. I also add a sufficient excess of oxygen to the sulphide of hydrogen so as
to produce with the sulphurous acid, sulphuric acid when the conditions for forming
such sulphuric acid may arise during the process. The mixture of sulphurous acid,
atmospheric air and steam I now convey through a mixture of hydrate of alumina
with chloride of potassium or of sodium at a suitable temperature. By this opera-
tion, I obtain as the ultimate product sulphate of potash or of soda mixed with
hydrate of alumina, that is to say, the mixture of materials with which I started the
process. This mixture of substances I then again convert, by the action of the
above mentioned hot reducing gases, into aluminate of potash or of soda, and obtain
again sulphide of hydrogen, which, when treated as above described, will furnish
a further supply of the alkaline sulphates, so that, theoretically speaking, the
same quantity of sulphur once introduced into the process will convert an unlimited
quantity of the alkaline chlorides into sulphates.
When the second or alternative method of working the process is to be adopted,
that is to say, when the sulphur introduced into the process from burning pyrites
is to be recovered as free sulphur, then the process is started and worked as
follows, viz. Chloride of potassium or of sodium is mixed with a suitable quantity
of hydrate of alumina. Into this mixture, a mixture of sulphurous acid,
atmospheric air and steam, (as practised in what is known as Hargreaves
process) is introduced in a convenient manner, the result being the formation
of a mixture of sulphate of potash or of soda with hydrate of alumina.
From the facility with which this conversion into sulphates takes place, it is
assumed that first of all sulphate of alumina is formed in the process, which
then more readily gives up its sulphuric acid to the chlorides named, decom-
posing the same thereby into sulphates. Sulphate of alumina is, in fact, found
to be formed in the intermediary stages of the process, but soon decomposed
again.
I will now describe more particularly in what manner the above mentioned
process may be carried into practice.
I. I mix, for the purpose of their conversion into sulphates and to render such
sulphates more suitable for use in the later stages of my process, chlorides of
potassium or of sodium either with native hydrate of alumina or with the hydrate
of alumina obtained as a bye-product in a subsequent part of my process (as
hereinafter described). The quantity of the hydrate of alumina so added, may
vary from say 30 per cent. to 100 per cent. of the weight of the chlorides
employed, a mixture of equal parts gave very good results. I add to this mixture,
-

page_text: a sufficient quantity of water to convert it into a stiff plastic mass, and mould the
same into bricks (preferably perforated), or balls, or pieces of other convenient
form. I then dry the moulded pieces or masses by waste heat or otherwise.
The conversion of the chloride in this mass, 1 carry out in a series of chambers
(or kilns or similar receptacles) connected together by flues in such a manner that
the gases conveyed into one of the said chambers can pass from it to the next, and
so on through the whole series. Each of the chambers should be provided with an
inlet and outlet for gases. Between every two chambers there should also be a
suitable valve (or similar arrangement) by means of which each chamber can be
put out of communication with the rest, for the purpose of charging it with fresh
material, or for discharging the finished product, without interrupting the process
going on in the remainder of the chambers.
The said chambers must further be so arranged that each chamber may in its
turn become the first, the last or an intermediate chamber of the series.
These chambers I fill with the dry moulded mixture; I then convey into and
through one of the same, a gaseous mixture of hot sulphurous acid, steam either
superheated or not, and atmospheric air, either hot or cold. From this chamber,
the said gaseous mixture passes through all the chambers connected at the time
with one another. At the beginning of the operation, the contents of the chambers
should be heated (by means of gaseous fuel or heated air) up to the temperature
favourable to the taking place of the desired reaction.
Assuming that twelve such chambers are put into operation and kept in full
normal working order, and that the said gases enter, for instance, into the second
chamber of the scries and pass from there to the chambers 3, 4, 5. &c., up to 11,
then chamber No. 1, will be discharging finished sulphate, whilst chamber No. 12
is being charged with fresh chloride mixture.
While, by the action of the said gaseous mixture upon the moulded chloride
mixture, the chloride in the same becomes ultimately converted into sulphate,
gaseous hydrochloric acid passes away (in the case under consideration) from the
chamber No. 11, from which it is conveyed, together with the residual gases
accompanying it, to the condensers.
Since each of the chambers takes in its turn the place of the chambers Nos. 2
and 11, respectively, each of the said chambers must be provided with an inlet for
the sulphurous acid and with an outlet for the hydrochloric acid gas, as well as with
connections for the conveyance of these gases.
A temperature of from 400 to 500 degrees Centigrade is suitable for the
beginning and continuance of the process above described. The reaction is most
energetic and runs its course quickly (provided there is an ample supply of the
sulphurous acid gas mixture) without any danger of the moulded chloride mass
fusing and thus becoming inactive, as is the case in the analogous Hargreaves'
process, both of which facts may be attributed to the admixture of alumina hydrate,
which, being temporarily converted into sulphate, transfers its sulphuric acid to the
alkaline chlorides.
The sulphurous acid gas mixture may, for the same reasons, be employed of
much greater richness, and the heat of the air and steam employed may, if desired,
he greater than is usual in the said Hargreaves' process.
It is, however, not desirable to allow the heat in the chambers to reach that at
which the hydrate of alumina loses its water of hydration. The sulphurous acid
gas mixture passes through each chamber from the top of the charge downwards.
The sulphurous acid employed for the above described process, I obtain, as has
already been mentioned above:-
(1.) By the combustion of the sulphide of hydrogen produced or obtained in the
second part of my process hereinafter described; or
(2.) By the burning or roasting of pyrites or other sulphurous ores.
By employing the latter method of producing the sulphurous acid gas, I am
enabled to recover, in the process, free sulphur as a bye-product in a quantity
approximately equal to that contained in the sulphurous acid employed.

page_text: II. The second part or stage of my process is as follows, viz. :-
As soon as the chloride in the mixture of alkaline chloride and alumina hydrate
in the first charged chamber has been converted into sulphate, the charge of that
chamber is withdrawn and (preferably hot as it is) charged into one of a series of
chambers which are distinct and separate from the series of chambers used for the
conversion into sulphate, and which may be similar in number and size and may be
arranged and worked in a similar manner.
Taking it for granted that the process in these chambers be in full normal and
continuous working condition, and all the chambers, not shunted out of connection
with the rest, fully charged with the mixture of alkaline sulphate and hydrate of
alumina, I convey into the chamber first charged with the said mixture, a current
of a reducing gas, for instance, hydrogen-gas, or carbonic oxide gas, or gases
containing the same, such as water-gas or other producer-gas generated with the aid
of steam, whilst such gases are nearly red hot, or are at the temperature at which
they leave the producers.
By the action of the said hot reducing gases upon the sulphate, the latter is
converted into the alkaline sulphide, which, on its part, reacts upon the alumina
hydrate, forming the corresponding alkaline aluminate, whilst the sulphur passes
away from it as sulphide of hydrogen. If the heat inherent in the reducing gases
should be found to be insufficient to effect the reduction of the sulphate, it may be
increased by admitting air (preferably heated) in such quantity to the reducing
gas (in one or more of the chambers) as to burn a small portion of the same.
The gases leaving the first charged -chamber of this series, pass from it to the
next and thence successively through the whole of the chambers connected with
one another, until they leave the last or one of the lastly charged chambers, as
much exhausted as is practically desirable, and strongly charged or mixed with
sulphide of hydrogen.
These gases strongly charged with sulphide of hydrogen may now be made use
of in two different ways:-
(a.) By mixing sufficient air thereto to convert the sulphide of hydrogen into
sulphurous acid and steam, and using this product for the conversion of further
quantities of alkaline chlorides in the above described manner, by conveying the
same to the respective chamber of the series in which part 1. of the process is
carried out, thus employing the same quantity of sulphur again and again for
the same purpose; or,
(b.) By recovering from the sulphide of hydrogen solid sulphur, which may be
effected by admitting so much air to the gases that only the hydrogen of the
sulphide of hydrogen is burnt, whereby sulphur in the form of vapour is obtained,
which is then conveyed into a suitable chamber and collected therein.
If it is desired to work the process above described under (a), then the whole
process beginning with the chloride and finishing with aluminate can be carried
out in one long series of chambers (worked in a similar manner to an annular
brick kiln) of about twice the length of that in which part I. of the process is
carried out, although, by this mode of working, the construction of the apparatus
is made more complicated. The course of the working of the whole process
comprised in parts I. and II. of the same, might be illustrated by imagining
the same to be carried out in a long channel or tube, into one end of which the
chloride mixture is continually being fed and then propelled along therein
towards the other end, whilst from the opposite end hot reducing gases are
constantly being passed through the same, and, at the same time, from about the
middle of the channel, air is being introduced for the combustion of the sulphide
of hydrogen, and the sulphurous acid formed is being conveyed towards the-end
into which the chloride mixture is being introduced. Since, by ideally or
theoretically perfect working, no part of the sulphurous acid would pass out of
the channel, the result of this proceeding would be that, at one end of the
apparatus, alkaline aluminate would be obtained, while, from the other end, only
hydrochloric acid gas would be conveyed. Thus the apparatus once stocked

page_text: with sulphur or the respective sulphurous compounds, this same quantity of sulphur
would perform its function for an unlimited time without any part of it ever
being perceptible outside the apparatus.
In my Provisional Specification, 1 described the process as commencing with
the introduction of the sulphate in order to show how the apparatus was being
supplied with the requisite working stock of sulphur.
The presence in and the passage through the sulphate mixture, of sulphide of
hydrogen, aids greatly in the reduction of the alkaline sulphates.
Of the two methods above mentioned for carrying out my process, I prefer,
however, that mentioned under (b). The mode of carrying out the same has
already been pointed out in the foregoing description and can be accomplished in
two different ways.
The above mentioned gases are either, from the particular chamber in the series
in which the reducing gases have been exhausted to the greatest extent and in
which they are found to be associated with the highest percentage of sulphide
of hydrogen, conducted into an apparatus for the recovery of sulphur from
sulphide of hydrogen by the process now known as the Claus process; or the
said gases may be mixed in the last of the chambers with the required quantity
of air, and the mixture be made to pass through this chamber in a downward
direction, where, in contact with the hot contents of the said chamber, free sulphur
is produced in the form of vapour, which is conveyed into collecting chambers.
When it is found that the charge in the chamber firstly charged, has been
converted, as far as is desired, into the respective alkaline aluminate, it is
discharged therefrom and subjected to the operation which forms the third part
or stage of my process.
III. This part of my process is as. follows, that is to say, the alkaline
aluminate is now dissolved in boiling water, the solution thus obtained is separated,
by subsidence, filtration and washing, from the insoluble residue. While the
solution is still at the boiling point, I now force through the clear solution, in a
series of vessels, carbonic acid gas or gases containing carbonic acid, for instance,
gases from a lime-kiln, by means of an air-compression apparatus, or the carbonic
acid may be forced through the mixture of water and alkaline aluminate, and
the solution of alkaline carbonate separated from the insoluble residue afterwards.
For this purpose, an apparatus may be used such as is employed by Chance in
carrying out the process for obtaining sulphide of hydrogen and sulphur from
alkali waste, as described by me in the Specification of former Letters Patent
granted to me and dated 31st December 1883, No. 5958.
Under the conditions mentioned, the hydrate of alumina is obtained in a heavy,
dense form easily filtered. Any undecomposed alkaline sulphide which might still
exist in the solution, is likewise decomposed by this operation. The sulphide of
hydrogen passing away with the residual gases may be dealt with in the
well-known manner.
The solution of alkaline carbonate resulting from this third part of the process,
being fully concentrated, is or may be utilised in the usual manner.
It is obvious that the part II, of the process, as hereinbefore described, is also
applicable when the alkaline sulphate has been obtained in any well-known manner.
It is, in this case, intimately inixed with hydrate of alumina, moulded in the
manner above described and further treated (as hereinbefore described) by means
of the aforesaid reducing gases, and then by the operations forming the third part
of my process.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
First. The manufacture of carbonate of potash or of soda, by converting the
chlorides of these alkalies in admixture with hydrate of alumina, first into sulphates

page_text: and then into aluminates, and then treating such aluminates by means of carbonic
acid or gases containing the same.
Second. The production of sulphate of potash or of soda by the action of a
mixture of sulphurous acid gas, vapour of water and atmospheric air upon a
mixture of hydrate of alumina with the chlorides of the said alkalies at an elevated
temperature.
Third. The herein described process of obtaining aluminate of potash or of soda,
by acting upon sulphate of potash or of soda in admixture with hydrate of alumina,
by means of hot reducing gases, such as hydrogen, or carbonic oxide, or gases
containing the same, so as to thereby simultaneously produce sulphide of hydrogen.
Fourth. The herein described process of obtaining carbonate of potash or of soda,
by decomposing the solutions of the aluminates of the said alkalies (produced as
hereinbefore described) by means of carbonic acid or gases containing the same,
and obtaining hydrate of alumina as a bye-product.
Fifth. The use of the hydrate of alumina- obtained in the above described
process, for the treatment of further quantities of the alkaline chlorides and
sulphates, substantially as herein before described.
Sixth. In the process above described, the use of the sulphur compounds once
introduced into the apparatus, for repeatedly converting fresh quantities of the
chlorides of the alkalies into sulphates, substantially as hereinbefore described..
Seventh. The continuous or cyclical process carried out as above described in
one or more series of chambers, and by which pure hydrate of alumina,
hydrochloric acid and carbonate of potash or of soda are obtained as ultimate
products, as set forth.
Dated the 10th day of
1001
C. F. CLAUS.
D. Young & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.
C. F. CLAUS.
D. Young & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.