IMPROVE- MENTS IN THE MANUFACTURE OF SULPHATE OF POTASH AND IN APPARATUS EMPLOYED THEREFOR.
Year: 1874

page_text: LETTERS PATENT to Charles Stuart Gorman, of Irvine, in the County
of Ayr, North Britain, Chemist, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF SULPHATE OF POTASH AND IN APPARATUS
EMPLOYED THEREFOR.'
"
Sealed the 4th August 1874, and dated the 6th June 1874.
PROVISIONAL SPECIFICATION left by the said Charles Stuart Gorman
at the Office of the Commissioners of Patents, with his Petition,
on the 6th June 1874.
I, CHARLES STUART GORMAN, of Irvine, in the County of Ayr, North
Britain, Chemist, do hereby declare the nature of the said Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE
APPARATUS EMPLOYED THEREFOR," to be as follows; that is to say :-
OF POTASH AND IN
This Invention relates to improvements in the manufacture of sulphate
of potash and in the apparatus employed therefor, whereby in de-
composing chloride of potassium by means of sulphurous acid (either
acted upon by metallic oxides or not) and along with atmospheric air:

page_text: and steam, and with or without chlorine, the said chloride is prevented
from fusing, the process of decomposition is facilitated, and the cost of
conversion into sulphate of potash is reduced. To effect these objects
there is mixed with the said chloride before subjecting it to the process
of conversion 10 per cent. of the weight of alkali or chrome waste.
Other substances may be substituted for alkali and chrome waste in
some cases with advantage, such as lime and magnesia, either separately
or in combination. Other proportions may however be used.
The Invention consists also in improvements in the said manufacture,
whereby in decomposing chloride of potassium, as aforesaid, the said
chloride is heated without the application of other than the aforesaid
gases, air, and steam, in a manner that conduces to the uniformity of
temperature of the whole mass in process of conversion; the application
of heat to the exterior of the decomposing chamber may thereby be
almost entirely dispensed with, and the chlorides are maintained in a
condition favorable to the process of conversion. To effect this object
the said sulphurous acid and other gas and vapours are introduced into
the decomposing chambers through a pipe which is carried through the
whole length of the inside of the chamber before the said gases and
vapours are allowed to mingle with the chlorides.
<6
The Invention consists further in improvements in the said manu-
facture, whereby in decomposing chloride of potassium, as aforesaid,
certain metallic oxides" unmixed with the chlorides are employed to
promote the oxidation of the sulphurous acid before it is introduced into
the chloride under conversion, and whereby the process of conversion is
facilitated. The "metallic oxides" preferred is the peroxide of iron, but
the oxide of manganese or the sesquixide of chronium may in some cir-
cumstances be substituted with advantage.
The Invention consists further in improvements in the said manu-
facture, whereby in decomposing chloride of potassium, as aforesaid, the
said gases, air, and steam are directed upon the said chloride in a manner
conducive to the diffusion of the said gases and vapours through or
amongst the said chlorides, and the process of decomposition is thereby
promoted. To effect this object the gas inlet pipe is terminated in or
about the centre of the top or bottom of the decomposing chamber
accordingly as the said pipe is led into it.

page_text: The Invention consists further in improvements in the said manu-
facture, whereby in decomposing chloride of potassium, as aforesaid,
chlorine is employed to promote the oxidation of the sulphurous acid
used in the process of decomposition, and the process is thereby facilitated.
To effect this there is introduced into the said inlet pipe chlorine
obtained by the usual process from the hydrochloric acid evolved in the
process or otherwise.
The Invention also consists in improvements in the said manufacture,
whereby in decomposing chloride of potassium, as aforesaid, nitric acid
obtained in the ordinary way is employed to promote the oxidation of
the sulphurous acid. To effect this object nitric acid is passed into the
said inlet pipe where it mingles with the sulphurous acid.
This Invention is practised in the following manner:-Sulphurous
acid and atmospheric air and steam are, according to one modification,
subjected to the action of metallic oxides without admixture with
chloride, such as peroxide of iron, oxide of manganese, and sesquixide of
chromium, either in combination or singly (peroxide of iron being pre-
ferred), and being so subjected are employed in the manufacture of
sulphate of potash by acting with them upon chloride of potassium
mixed with alkali waste, chrome waste, and in some cases lime and
magnésia, either separately or. in combination, the proportion of
the latter admixtures being as 10 parts by weight to 100 parts of the
former.
By another modification chlorine is used with the said sulphurous
acid, atmospheric air, and steam.
By another modification nitric acid is used with the said sulphurous
acid, atmospheric air and steam. The process is carried on in an
apparatus consisting of metal chambers, so arranged that the converting
agents may be introduced into any one of them and pass on along with
the hydrochloric acid evolved into another, and from it to a third or
any larger number of chambers that may be desired so as to secure the
complete utilization of all the sulphurous acid. Each chamber is pro-
vided with an inlet pipe for the gases and an outlet pipe for the passage
of the unabsorbed gases and hydrochloric acid. The inlet pipe contains
the "metallic oxides" and is passed through the length of the cylinder
for the purpose of heating the materials in the chambers, and terminates

page_text: in the centre of the chamber at or near a point in the centre of that end
of the chamber farthest from the point at which the pipe entered it.
The hydrochloric acid evolved is used in carrying out one modification
of the Invention to furnish the chlorine required by decomposing it in
the usual method, or it can be condensed in the ordinary way. The
contents of the said decomposing chambers are maintained at or about
the melting temperature of lead, but a lower or higher temperature may
in some cases be maintained with advantage.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Stuart Gorman in the Great Seal Patent
Office on the 4th December 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
STUART GORMAN,. of Irvine, in the County of Ayr, North Britain,
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of June, in the year of our
Lord One thousand eight hundred and seventy-four, in the 37th year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Charles Stuart Gorman, Her special license that I,
the said Charles Stuart Gorman, my executors, administrators, and
assigns, or such others as I, the said Charles Stuart Gorman, my
executors, administrators, or 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 SULPHATE OF POTASH AND.IN APPARATUS
EMPLOYED THEREFOR," upon the condition (amongst others) that I, the said
Charles Stuart Gorman, 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.

page_text: NOW KNOW YE, that I, the said Charles Stuart Gorman, 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 accompanying
Drawings and to the letters and figures marked thereon, that is to
say:-
My said Invention relates to improvements in the manufacture of
sulphate of potash and in the apparatus employed therefor, whereby in
decomposing chloride of potassium by means of sulphurous acid (either
acted upon by metallic oxides or not) together with atmospheric air and
steam, the process of decomposition is facilitated and the cost of
conversion into sulphate of potash is reduced.
.
In carrying my said Invention into practice the chloride of potassium
before being subjected to the process of decomposition into sulphate of
potash is mixed with about 10 parts by weight of alkali waste or chrome
waste to every 90 parts by weight of the chloride of potassium, by which
means the said chloride is rendered more porous and is prevented from
fusing during subsequent operation. The compound or mixture of
chloride of potassium with alkali waste or chrome waste is with the
addition of a little water formed into slabs, cakes or "biscuits," and
these are placed in an oven or suitable drying chamber, which forming
no part of this Invention is not illustrated on the Drawings hereunto
appended, but in which the said slabs, cakes, or " biscuits are sub-
mitted to the action of heat and baked to the degree of hardness
necessary to fit them for introduction into the converting or decomposing
chambers wherein the chloride of potassium is converted into sulphate
of potash.'
"
In lieu of admixing the chloride of potassium with alkali or chrome
waste it may be admixed with lime or magnesia separately or with a
combination or mixture of lime and magnesia, for the purposes herein-
before set forth, the proportion of such admixture being about 100 parts
by weight of the chloride to 10 parts by weight of lime or magnesia, or
the combination or mixture of lime and magnesia. It is however pre-
ferred to employ alkali waste or chrome waste, and of these alkali waste
is found most suitable for the purposes of this Invention.
My said Invention consists also in other improvements in the manu-
facture of sulphate of potash, whereby in decomposing the chloride of

page_text: potassium in converting chambers, as aforesaid, certain metallic oxides
unmixed with the chloride are employed to promote the oxidation of the
sulphurous acid before it is introduced into or among the slabs, biscuits,
or cakes of chloride under conversion, and by which means the process
of conversion is facilitated. The metallic oxide preferred is the peroxide
of iron, but peroxide of manganese and the sesqui-oxide of chromium
may in some circumstances be substituted with advantage.
My said Invention further consists in improvements in the said manu-
facture, whereby in decomposing chloride of potassium, as aforesaid, the
chloride is or can be heated without the application of gases or vapours
other than the sulphurous acid, air, and steam, as aforesaid, and in a
manner which conduces to the uniformity of temperature of the whole
mass in process of conversion, the application of heat to the exterior of
the decomposing chambers may therefore be almost entirely or in a
great measure dispensed with, whilst the chlorides are at the same time
maintained in a condition favorable to the process of conversion. To
effect this object the sulphurous acid, air, and steam or vapour are
introduced into the decomposing chambers through pipes in which the
metallic oxide employed to promote the oxidation of the sulphurous acid
is placed, and which pipes are carried throughout cach chamber and
terminated at or about the centre of the top or bottom, or other suitable
part thereof, according as the pipes are led into the chambers from the
top, bottom, or side. By this means the gas is carried throughout
the whole length of the chambers before being allowed to mingle with the
chloride, whereby heat is imparted to the chloride, the oxidation of
the sulphurous acid is promoted, the gases are directed upon the chloride
in a manner conducive to their diffusion through or amongst them, and
the process of decomposition is by these several means facilitated.
In lieu of promoting the oxidation of the sulphurous acid employed.in
the decomposition of chloride of potassium as practised under this Inven-
tion by metallic oxides placed in the inlet pipes, as herein-before
described, the oxidation of the sulphurous acid used in the process of
decomposition may be promoted by passing chlorine or nitric acid into
the inlet pipes, and which may be obtained under the usual modes of
producing chlorine and nitric acid.
And in order that my said Invention may be properly understood, I
now proceed more particularly to set forth the arrangement of apparatus

page_text: аци 4.
As shown on the Drawings, a series of 6 chambers A. form one setting,
but any
other suitable number, greater or less, of these chambers may
constitute one set or range. The converting or decomposing chambers A
are made of metal and surrounded with brickwork B, an annular space a
being left between the inner side of the setting and the exterior of each
chamber A, as shewn, charging doorways d are formed in the tops of
cach chamber A through which the slabs, "biscuits," or cakes, com-
posed, as herein-before described, of chloride of potassium and alkali or
chrome waste, or of chloride of potassium admixed with lime or
magnesia, or with a combination of these, are charged into the interiors
of the chambers. The bottoms C of the chambers rest on brickwork
supports, D, and in the longitudinal space between these supports the
pipe E through which the sulphurous acid, gas, air, and steam is conducted
to each chamber is situated. The pipe E communicates with pyrites,
burners, in which the sulphurous acid gas is generated in the ordinary
manner, and with steam and atmospheric air pipes, and from the said
pipe E branch pipes F lead to the bottom of each chamber A, as more
particularly seen at Figure I. of the Drawings. The sulphurous acid
gas, air, and steam conducted through the branch pipes F pass into.
pipes G placed at the interiors of the chambers, and whereby the gas,
air, and steam are conducted to the upper end of each chamber before
being allowed to pass into or amongst the chloride contained therein.
In the pipes G the metallic oxide or oxides herein-before specified,
either alone or in combination, are placed (when sucli are used for
promoting the oxidation of the sulphurous acid), whereby the oxide or
oxides are kept separate from the chloride surrounding the pipes G.

page_text: When chlorine or nitric acid is used to promote oxidation of the
sulphurous acid these are conducted into the pipes G by other branch
pipes connected thereunto, but which are not shown on the Drawings.
Supposing the chamber marked X to be the first of the series, it being
understood that any one chamber may be made the first or the last of
the range at pleasure, and also that any one or more of the chambers
may be left out of operation whilst the decomposition and conversion of
chloride of potassium into sulphate of potash is being effected in tho
others. The decomposing gases being conducted into the pipe E, and
being prevented from passing further therethrough than the flanches e
(by unscrewing the bolts at these flanches and inserting a thin diaphragm
or plate of metal between them, and thereafter again securing the
flanches together) pass upwards through the branch F and thence
through the pipe G, from whence they circulate downwards, as indicated
by the arrows, through or amongst the chloride until the bottom of
the chamber is reached, from whence the unabsorbed decomposing gases
together with the hydrochloric acid produced by the action of the
decomposing gases upon the chloride pass outwards through the pipe H
and are thereby conducted back into the pipe E, from whence they
again pass upwards through the next branch F and into the chamber A
in communication therewith, and so on until the last chamber is reached,
it being understood that the passage of the decomposing gases further
than the flanches on the pipe E at the right-hand side of each branch F
is prevented by a plate or diaphragm inserted between the flanches, as
herein-before described. From the last chamber A of the series the
hydrochloric acid produced by the action of the decomposing gases in
all the chambers passes through the pipe H and thence through the
pipe I into the flue J, and may thereafter be condensed or employed in
generating chlorine for oxidising the sulphurous acid in the pipes G
when chlorine is employed for that purpose. It is preferred that the
number of chambers employed should be sufficient to ensure the
absorption of all the sulphurous acid. Supposing the chamber Y to be
the first of the series, the chamber Z to be out of operation, and the
chamber X to be the last of the series, the sulphurous acid, air, and
steam are prevented from passing into the chambers X and Z by
diaphragms or thin metal plates inserted between the flanches of the
branch pipes F at g and f, Figure 1.
The decomposing gases after passing downwards .through or amongst
the chloride in the chamber Y, and thence with the hydrochloric acid

page_text: on through successive chambers to that at the end of the range, the
gases instead of then passing off to the flue J, as formerly described, are
prevented from passing thereinto by a diaphragm or plate inserted at /,
Figures 1 and 2, the uṇabsorbed decomposing gases together with the
hydrochloric acid therefore pass upwards into the pipe K which com-
municates with each of the branch pipes F, as shewn more particularly
at Figure 4. Communication between the branch inlet pipes F of the
chambers from Z inclusive to the right-hand end of the range is pre-
vented by plates or diaphragms inserted between their junction flanches,
as herein-before described, so that the unabsorbed decomposing gases
and the hydrochloric acid find no outlet from the pipe K until the
branch inlet F of the chamber X is reached, through which the gases
pass upwards, and after circulating downwards through or amongst the
chloride contained in the said chamber are led away to the flue J
through the pipe L, Figures 2 and 4, the exit of the gases through the
pipe H into the chamber Z being prevented by inserting a diaphragm
at the flanches 7. Similarly any other chamber than Z may be left out
of operation, and any other chambers than X and Y may be constituted
the first and last of the series, it being understood that it is preferred to
make the chamber most recently charged with chloride that through
which the weakest or last portion of the unabsorbed decomposing gases
are conducted, that is to say, the last of the series.
In operating with the apparatus now under reference the temperature
of the contents of the chambers A is maintained at or about the tem-
perature of melting lead, and should the heat generated within tho
chambers themselves, by the chemical action of the decomposing gases on
the chloride, be insufficient to maintain the contents of the chambers at
that temperature, additional external heat may be applied by conducting
heated air through the pipe N, from whence it passes into the annular
spaces a surrounding the chambers through the branch pipes m; and
after circulating around the said chambers is conducted away therefrom
through branches n into the pipe M. Cocks or valves o are provided
in the pipe m to regulato or cut off the supply of heated air to or from
the several chambers. Should the temperature within the chambers A
become too great cold air may in like manner be conducted around the
exterior thereof.
After the slabs. biscuits, or cakes of chloride of potassium admized

page_text: t
described, have been placed in the chambers A, and before the de-
composing gases are introduced thereinto, a stream of hot air is or may
be blown into each chamber to heat the chambers and chloride of
potassium. It is preferred to so employ the heated air at from 400
to 600 degrees Fahrenheit.
Figure 5 of the Drawings is a vertical section of one chamber; and
Figure 6 is a plan of the same on which the method of introducing the
heated air to the interior of the chamber is illustrated. A is the heated
air pipe from which the branch B provided with a cock or valve C
conducts the heated air to the upper part of the chamber, as shewn.
It is to be here understood that I do not confine myself to arrange the
apparatus employed in the manufacture of sulphate of potash under this
Invention, precisely in the manner heréin-before described and shewn
on the appended Drawings, as modifications may be effected thereon;
for example, the sulphurous acid, air, and steam in lieu of being con-
ducted into the pipe G at the lower end thereof and thereafter passing
downwards through the chloride may be led into the said pipes at their
upper ends, and from the lower ends of the said pipes be caused to pass
upwards through each decomposing chamber, in which case the pipes H
are reversed from the lower to the upper ends of the chambers, and
instead of arranging the decomposing chambers A. in a single line, as
shewn on the Drawings, the said chambers may be arranged in a double
line, square, oblong, circular, or other 'suitable figure; nor do I confine
myself to the position of the pipe G, shewn on the Drawings, nor to the
proportions of admixture of the chloride of potassium with alkali or
chrome waste, lime or magnesia, herein-before stated, in preparing the
said chloride for conversion into sulphate of potash, as other proportions
of admixture may be adopted; but I find that those already mentioned
give good results.
The sulphurous acid, air, and steam may be superheated by any
suitable means before being conducted into the pipes G.
Having now described and particularly ascertained the nature of my
said Invention, and the system, mode, or manner in or under which the
same is, or may be used, or carried out in practice, I would observe in
conclusion that I do not claim as forming part of this Invention the
oxidising of the decomposing gases by metallic oxides, otherwise than in
the manner herein-before described. What then I consider to be novel

page_text: and original and therefore- claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,-
First. Mixing the chloride of potassium with alkali waste, chrome
waste, lime, or magnesia, as and for the purposes herein-before
described.
Second. The general arrangement and construction of apparatus
illustrated on the appended Sheet of Drawings, or any mere modification
thereof, and the employment of the same in the manufacture of sulphate
of potash, substantially as herein-before described.
Third. Introducing sulphurous acid, air, and steam into the de-
composing chambers through the pipes in which the oxides are con-
tained, or into which they are passed, so that the gases and vapours are
conducted throughout the chambers and impart heat to the chloride
before being allowed to mix therewith, and whereby they are more
thoroughly diffused through the same, substantially as herein-before
described.
Fourth. The employment of metallic oxides, unmixed or out of
contact with the chloride to promote oxidation of the sulphurous acid,
as it passes through the pipes G and before it is introduced into or
amongst the chloride, substantially as herein-before described.
Fifth. The employment of chlorine to promote the oxidation of the
sulphurous acid, as and for the purpose herein-before described.
Sixth. The employment of nitric acid to promote the oxidation of the
sulphurous acid, as and for the purpose herein-before described.
In witness whereof, I, the said Charles Stuart Gorman, have here-
unto set my hand and seal, this Third day of December, One
thousand eight hundred and seventy-four.
CHARLES STUART GORMAN.. (L.S.)