IMPROVEMENTS IN THE PRODUCTION OR SEPARATION OF SULPHUR FROM NATIVE ORES AND OTHER SUBSTANCES, AND IN THE APPARATUS FOR EFFECTING THE SAME
Year: 1879

page_text: LETTERS PATENT to Owen Charles Dalhousie Ross, of 50, Trafalgar Road,
Peckham, in the County of Surrey, Civil Engineer, for the Invention of
"IMPROVEMENTS IN THE PRODUCTION OR SEPARATION OF SULPHUR FROM
NATIVE ORES AND OTHER SUBSTANCES, AND IN THE APPARATUS FOR
EFFECTING THE SAME."
Sealed the 15th August 1879, and dated the 21st February 1879.
PROVISIONAL SPECIFICATION left by the said Owen Charles Dalhousie
Ross at the Office of the Commissioners of Patents on the 21st February
1879.
OWEN CHARLES DALHOUSIE Ross, of 50, Trafalgar Road, Peckham, in the
County of Surrey, Civil Engineer. "IMPROVEMENTS IN THE PRODUCTION OR
SEPARATION OF SULPHUR FROM NATIVE ORES AND OTHER SUBSTANCES, AND IN
THE APPARATUS FOR EFFECTING THE SAME.”
My Invention consists, first, in the application of superheated steam to the pro-
duction or separation of sulphur by volatilisation or distillation from native ores
impure or rough brimstone, spent oxide or sulphate of iron, or (Laming's mixture)
after they have been used in the purification of gas and from other bodies in
which free sulphur is met with in combination with substances foreign to it, such as
sulphate or carbonate of lime or of soda, as in the residues obtained obtained in
alkali works, &c., but it does not include the application of superheated steam to iron
or copper pyrites in which the sulphur is chemically combined with those ores.
It consists, secondly, in the means of separation of the sulphur from the steam.
It is well known that sulphur, which melts at a temperature of 239° F., or there-
abouts, can be separated from native ores by the use of steam under pressure, by
which means that temperature can be easily obtained, and that the greater part of
the sulphur will then run from the ore as a liquid, but in order to volatilise
or convert sulphur into vapour it requires to be heated to a temperature of 700°
or 800° F., or even more, and such temperature cannot be attained with safety in a
steam boiler because they would require a pressure of several hundred pounds per
square inch. I obtain this high temperature by passing the steam after it leaves
the boiler through a coil or coils of hot iron pipes or some other form of steam
superheater and then conduct it into the retort, or oven, or other vessel or chamber
containing the ores or other materials with which the sulphur is combined.

page_text: By this means the sulphur is heated to the required temperature, and the whole
or very nearly the whole of it is converted into vapour, which mixos with the steam
and is carried away in combination with the steam to the condensers.
With the view of economising superheated steam I sometimes partially heat the
chamber or oven in which the sulphur is volatilised by means of fire used externally,
or by conducting hot products of combustion or hot air through flues into the
chamber or oven, or to the outer surface of it, or I use a retort revolving in or over
a furnace, or in hot flues.
When I apply my Invention to the volatilisation or refining of impure or rough
brimstone this may sometimes be effected by passing a jet of steam, either super-
heated or under pressure only into or near to the exit from ordinary refining retorts
or pots, and from thence into the condensers.
The steam will then be partly or entirely superheated in the retorts themselves
or at the moment of mixing with the sulphur vapour, and this facilitates the distil-
lation or process of refining by acting as an exhaust and conveying the sulphur
vapour more rapidly away from the retorts or pots to the condensers, in which also
it may be so utilised as to greatly facilitate the condensation.
In order to effect the condensation or separation of the sulphur from the steam it
can either be allowed to issue into spacious chambers resembling those employed in
the ordinary process of refining sulphur, or I prefer to cause the mixed steam and
sulphur vapour to strike successively against a number of hard surfaces in one or
more tubes or chambers, or to conduct it into condensing coils, or into water, or into
one or more flues, pots, or pipes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Owen Charles Dalhousie Ross in the Great Seal Patent Office on the
21st August 1879.
OWEN CHARLES DALHOUSIE Ross, of 50, Trafalgar Road, Peckham, in the
County of Surrey, Civil Engineer. "IMPROVEMENTS IN THE PRODUCTION OR
SEPARATION OF SULPHUR FROM NATIVE ORES AND OTHER SUBSTANCES, AND IN
THE APPARATUS FOR EFFECTING THE SAME."
My improvements relate, first, to an application of and apparatus for applying
superheated steam to the separation and recovery of sulphur by volatilisation or
sublimation from the substances commonly called spent oxides of iron, spent sul-
phates of iron and Laming's, or other similar mixtures after they have been used for
the purification of gas, and I effect this by treating the sulphur materials with
superheated steam, the temperature being so regulated as to thoroughly vaporise the
sulphur in the materials treated, and at the same time to avoid the decomposition
either of the steam or of the oxides or sulphates, which insures on the one hand the
recovery of very nearly the whole of the free sulphur contained therein, and on the
other hand leaves the oxides and sulphates so little affected in their chemical con-
dition that after the conclusion of the process of sublimation they can be rehydrated
and then used again. for the purification of gas. The separation by the use of
superheated steam of sulphur from spent oxides used in the purification of gas
so as to prepare them for revivification and subsequent use forms an important
feature in my Invention.
The apparatus which I employ for the above purpose, and which will be.
hereinafter more fully described, can be also applied in a similar manner to the
sublimation or refining of sulphur contained in native brimstone ores and impure
or rough brimstone, and to its separation from other substances in which free
sulphur is net with in combination with sulphates or carbonates, &c., of soda or of
lime, such, for instance, as the residues which are recovered in alkali works by
Mond's and other similar processes. My process however is not applicable to iron
or copper pyrites in which the sulphur is chemically combined with those metals,
and could only be separated from them by chemical decomposition, requiring the
use of extremely high temperatures, which, as above described, I avoid.
Wherever the materials upon which I operate are not already in a finely divided
state I reduce them to powder or break them up into very small pieces.
The sulphur vapour when volatilized or sublimed at the temperature above
indicated mixes with the steam; and my improvements consist, secondly, in the
means by which I condense or separate the recovered sulphur from the steam.
For the purposes of sublimation I employ very shallow vessels or shelves, which
I form of a number of plates or shelves placed one above the other or side by side,
and I surround these with an outer shell of metal or fire clay so as to form a steam
tight oven. I place the pulverized sulphur materials upon the shelves and I conduct
the steam into the interior of the oven through pipes after forcing it through a
superheater or superheaters. When the shell or oven is of a large size I carry the
steam to all parts of it so that it may play directly upon the pulverised
material and upon the aforesaid plates or shelves, and that it may come as
much as possible into direct contact with the substances from which the sulphur
is to be recovered immediately after issuing from the hot steam pipes.
The
I carefully graduate the temperature of the steam to that at which sulphur sublimes,
or thereabouts, in other words, to the temperature at which sulphur boils and is
converted into vapour, but care must be taken not much to exceed the boiling
temperature, which is usually computed and taken to be about 850° F.
temperature may however be allowed to vary between 600° F (at which some
vapour is formed) and 900° F., but it should not be allowed to exceed 1000° F.,;
or thereabouts, bearing in mind that the product which it is desired to obtain

page_text: is not any specie of gas but sulphur vapour, and that an excessive temperature
when applied to the spent oxides and sulphates would affect their chemical
composition to such an extent that besides wasting much of the sulphur it
would render them unfit for being used again for the purification of gas.
In order to conduct the operation rapidly and economically it is desirable that
the layers of spent oxide or other substances should generally not much exceed
half an inch in thickness. After the superheated steam has remained for a short
time in contact with such layers sulphur vapour is formed, and when the steam is
sufficiently charged therewith I conduct it away through steam pipes to the con-
densing apparatus; but sometimes before doing this I allow it to pass round
successively through one or more similar ovens and so economise heat, and
afterwards it goes forward to the condenser, where it is treated as hereinafter
described.
In order to effect the condensation or separation of the sulphur vapour from the
from the steam I use one or other of the following means which respectively form part
of my Invention:-When it is desired to recover the sulphur in the liquid form I
conduct the mixed steam and sulphur vapour to and through a worm or coil placed in
a tank or boiler in which the water is kept at the temperature of 240° F. to 250° F.,
or thereabouts, being the temperature at which sulphur melts, and keeps a good
yellow color. The sulphur vapour is by this means condensed as it passes through
the coil, and is reduced to the liquid form, and I connect with the bottom of the coil
a specie of well or reservoir in which the liquid sulphur accumulates, and from which
it is drawn off into moulds from time to time, whilst the steam after being freed
from sulphur passes off..from above the accumulated liquid and is conducted away
where it may be required. In some cases the sulphur vapour and steam may after.
having been properly cooled be conducted into a boiler containing water whose
temperature is about from 240° F. to 250° F., and the sulphur will in that case also
be separated and be deposited at the bottom of the boiler, where it is recovered by
any convenient means.
When it is desired to recover the sulphur in the solid form or as flour I conduct
the current of mixed steam and sulphur vapour to a steam tight vessel or vessels
containing a number of diaphragms, or strainers, or filters, or other obstacles which
permit the passage of the steam, but each of which retains a portion of the finely
divided sulphur as it strikes successively against them, and the diaphragms should
be sufficiently numerous to recover the whole of the sulphur before the steam passes
away from the vessel or vessels in which they are contained.
I apply that part of my Invention which relates to the recovery of sulphur from
the mixture of sulphur vapour and steam to the treatment of ordinary impure or
rough brimstone, and I proceed as follows:-I pass a jet of steam into or near to
the exit from ordinary refining retorts or pots, and from thence into the condensers
used by me. Sulphur vapour is so much heavier than air that it rises with difficulty
from the mass under treatment, and are of the effects produced by the introduction
of, a jet. of steam is in this case to facilitate the distillation by causing the steam to
act, as an exhaust, thus lessening the weight of vapour in the retort. The sulphur
vapour mixes with the steam and is more rapidly carried away from the retorts or
pots to the condensers, but the most important effect of the said jet of steam so
applied is that it allows of the application to ordinary refineries of my improved
sulphur condensing apparatus hereinbefore described. The sulphur vapours thus
obtained from the treatment of ordinary impure brimstone are by adopting my
condensing apparatus recovered better and far. more economically than by the
ordinary process.
Having described my Invention and the manner. of carrying it into effect, I
claim,―
First. The method of recovering sulphur from substances such as spent oxides of
iron or other materials containing free sulphur by heating the same with superheated
steam and condensing the sulphur vapours, substantially as described.
1. Secondly. The method of recovering sulphur from substances such as spent oxides

page_text: or other materials containing free sulphur by treating the same with superheated
steam and conducting the currents of mixed steam and vapours into chambers or
vessels where the currents impinge against diaphragms or other obstacles, and are
thereby made to deposit sulphur, substantially as hereinbefore described.
Thirdly. The separation by the aid of superbeated steam of sulphur from spent
oxides used in the purification of gas so as to prepare the oxides for revivification.
for subsequent use.
Fourthly. The application of the process of condensation to the treatment of
materials containing free sulphur or impure or rough brimstone by conducting
sulphur vapours mixed with steam either into a worm surrounded by heated water,
or into a boiler containing heated water, so as to separate and thereby recover the
sulphur.
In witness whereof, I, the said Owen Charles Dalhousie Ross, have hereunto
set my hand and seal, this Twentieth day of August, in the year of our Lord
One thousand eight hundred and seventy nine.
OWEN CHARLES DALHOUSIE ROSS. (L.S.)