IMPROVEMENTS IN TREATING AND OBTAINING PRODUCTS FROM SPENT OXIDE OF IRON WHICH HAS BEEN USED IN GAS WORKS, OR OTHER- WISE TO SEPARATE SULPTUR FROM SULPHURETTED HYDROGEN, AND IN THE PURIFICATION OF SULPHUR OBTAINED FROM SUCH OXIDE OF IRON
Year: 1868

page_text: LETTERS PATENT to Benjamin Edward Reina Newlands, F.C.S., of
4, Malvern Terrace, Charlton, in the County of Kent, for the
Invention of "IMPROVEMENTS IN TREATING AND OBTAINING PRODUCTS FROM
SPENT OXIDE OF IRON WHICH HAS BEEN USED IN GAS WORKS, OR OTHER-
WISE TO SEPARATE SULPTUR FROM SULPHURETTED HYDROGEN, AND IN THE
PURIFICATION OF SULPHUR OBTAINED FROM SUCH OXIDE OF IRON."
Sealed the 23rd June 1868, and dated the 18th March 1868.
PROVISIONAL SPECIFICATION left by the said Benjamin Edward
Reina Newlands at the Office of the Commissioners of Patents,
with his Petition, on the 18th March 1868.
I, BENJAMIN EDWARD REINA NEWLANDS, F.C.S., of 4, Malvern
Terrace, Charlton, in the County of Kent, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN TREATING AND OBTAIN
ING PRODUCTS FROM SPENT OXIDE OF IRON WHICH HAS BEEN USED IN GA
WORKS, OR OTHERWISE SEPARATE SULPHUR FROM SULPHURETTED HYDROGEN
AND IN THE PURIFICATION OF SULPHUR OBTAINED FROM SUCH OXIDE OF IRON,"
to be as follows:-

page_text: has been used in gas works, or otherwise to separate sulphur from
sulphuretted hydrogen, and in the purification of sulphur obtained
from such oxide of iron. The sulphur can be dissolved out from
spent oxide of iron by means of naptha, mineral oils, benzole, or
turpentine, but the use of such solvents generally leaves the oxide
of iron in a state unfit for use in purifying gas, or otherwise again
to separate sulphur from sulphuretted hydrogen.
According to my Invention I fit it to be so re-used by washing it
with bi-sulphide of carbon, and by this means I separate the
remaining naptha, mineral oils, benzole, or turpentine, and leave
the oxide of iron clean and fit for re-use. I recover the bi-sulphide
which the oxide absorbs by distillation. Where the oxide of iron has
been used for purifying coal gas after the sulphur has been removed
as above described, or with bi-sulphide of carbon, I wash it with
water, and so obtain a solution which I distil with lime, and I collect
the ammonia given off in an acid. Or, I add to the solution potash
or soda and evaporate so as to obtain sulpho-cyanide of potassium or
sodium, collecting the ammonia as before. The washed oxide I
further treat with lime and water, and so obtain ferrocyanide of
calcium which I either evaporate to obtain in crystals or to which
I add carbonate of potash which precipitates the lime, leaving ferro-
cyanide of potassium in solution which I afterwards crystallize out.
Or, I add to the oxide from which the sulphur has been separated
lime and water and boil, collecting the ammonia in acid, and I take the
lime solution thus obtained and add to it carbonate of potassa which
precipitates the lime as carbonate, leaving ferrocyanide of potassium
in solution which may then be obtained in crystals in the usual
way; or I precipitate Prussian blue from the lime solution by the
addition of hydrochloric. or sulphuric acids and a proto or per salt
of iron, or both; or what has the same effect I add a proto-salt of
iron and subsequently chloride of lime. This Prussian blue may
then be dried for sale, or may be converted into ferrocyanide of
potassium by the addition of caustic potassa. The oxide of iron
which remains after the lime and water treatment above described
I fit to be re-used for purifying coal gas by adding to it sulphate
of iron, which combines with the excess of lime left in the oxide.
forming oxide of iron and sulphate of lime. The oxide may be
dried if requisite. When it is not desired to re-use the spent oxide of
iron which has been used for the purification of coal gas I prepare

page_text: it to be burnt in the manufacture of sulphuric acid by washing it
with a strong solution of sulphur in bi-sulphide of carbon; by this
means I separate tar and other impurities, which if left in the oxide
cause a large expenditure of nitre in producing sulphuric acid from
it. Also, when sulphur is separated from spent oxide of iron by
means of naptha, mineral oils, benzole, or turpentine, the
sulphur remains much contaminated with the solvent, I according to
my Invention remove this contamination by treating it with bi-sulphide
of carbon or a solution of sulphur in that liquid. When bi-sulphide
of carbon is used to dissolve sulphur out of spent oxide of iron I
separate the sulphur from the solvent by adding to the solution
naptha, mineral oils, benzole, or turpentine; the sulphur may after-
wards be washed with bi-sulphide of carbon or a solution of sulphur
in that liquid. In this case I recover the bi-sulphide of carbon by
distillation, and the same is the case whenever in the above processes
I obtain a mixture of naptha, mineral oils, benzole or turpentine and
bi-sulphide of carbon.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Benjamin Edward Reina Newlands in the Great
Seal Patent Office on the 17th September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, BENJAMIN
EDWARD REINA NEWLANDS, F.C.S., of 4, Malvern Terrace, Charlton,
in the County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of March, in the
year of our Lord One thousand eight hundred and sixty-eight, in
the thirty-first year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Benjamin Edward Reina
Newlands, Her special licence that I, the said Benjamin Edward
Reina Newlands, my executors, administrators, and assigns, or such
others, as I, the said Benjamin Edward Reina Newlands, 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

page_text: IN TREATING AND OBTAINING PRODUCTS FROM SPENT OXIDE OF IRON WHICH
HAS BEEN USED IN GAS WORKS, OR OTHERWISE TO SEPARATE SULPHUR FROM
SULPHURETTED HYDROGEN, AND IN THE PURIFICATION OP SULPHUR OBTAINED
FROM BUCH OXIDE OF IRON," upon the condition (amongst others) that I,
the said Benjamin Edward Reina Newlands, my executors or adminis-
trators, by an instrument 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 Benjamin Edward Reina Newlands,
do hereby declare the nature of the 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:
This Invention has for its object improvements in treating and
obtaining products from spent oxide of iron which has been used in
gas works, or otherwise to separate sulphur from sulphuretted hydrogen,
and in the purification of sulphur obtained from such oxide of iron.
The sulphur can be dissolved out from spent oxide of iron by means
of naptha, mineral oils, benzole, or turpentine, but the use of such
solvents generally leaves the oxide of iron in a state unfit for use in
purifying gas, or otherwise again to separate sulphur from sulphuretted
hydrogen.
According to my Invention I fit it to be so re-used by washing it
with bi-sulphide of carbon, and by this means I separate the remaining
naptha, mineral oils, benzole, or turpentine, and leave the oxide of iron
clear and fit for re-use. I recover the bi-sulphide which the oxide
absorbs by distillation. For this purpose I prefer to use a cylindrical
wrought-iron air-tight vessel about 6 feet hight and 4 feet in diameter,
provided with a false bottom a few inches from the real bottom, two
manholes, one at the top and the other on the side on a level with the
false bottom; two pipes, one leading into the top and the other into
the bottom for ingress and egress of the bi-sulphide of carbon; a steam
pipe under the false bottom for blowing steam into the vessel, and a
large pipe or still head at the top which is connected with a worm
condenser, I proceed to extract the impurities from the oxide as follows:

page_text: -I place about one ton of the spent oxide from which the sulphur
has been removed into the vessel and run about twice its bulk of
bi-sulphide of carbon on to it, and allow it to digest for a short time;
I then run off the bi-sulphide into a distilling apparatus, and distil and
so recover the bi-sulphide again. The small quantity of bisulphide
adhering to the oxide I recover by blowing steam through the mass
when the bi-sulphide is volatalized and condensed in the worm condenser.
The oxide left after the above treatment, or after the sulphur has been
removed by bi-sulphide of carbon alone, contains (provided it was
originally used for purifying coal gas), sulpho-cyanide of ammonium
and other compounds of ammonia; these, according to my Invention,
I wash out with water either hot or cold, and boil the liquid so obtained
with lime in an iron or lead vessel, and pass the ammonia given off
through a pipe to the bottom of the vessel containing an acid
preferably sulphuric or hydrochloric. By this means I obtain a nearly
pure salt of ammonia. I sometimes convert the sulpho-cyanide of
ammonium contained in the water solution into sulpho-cyanide of
potassium or sodium by the addition of potash or soda instead
of lime to the solution, and I collect the ammonia given off as
before in an acid: I evaporate the solution and obtain the sulpho-
cyanide in crystals. The oxide of iron left after the above treatment
still contains cyanogen compounds, which are insoluble in water and
which I utilize as follows:-I place the oxide after it has been washed
with water in a tank having a false bottom, and add from 5% to 10% of
lime and about twice its bulk of water, and stir the mixture so as to
mix it thoroughly. I allow the mixture to stand for twelve hours and
run the clear liquid off through a hole in the bottom of the tank. In
this way I obtain a solution of ferrocyanide of calcium, which I either
crystallize out or convert into ferrocyanide of potassium by the addition
of enough carbonate of potassa to precipitate the lime in the solution
as carbonate of lime; or I add to the oxide from which the sulphur
has been removed a certain quantity of lime and water and boil; or I
drive steam through the mixture, collecting the ammonia evolved in
either case in an acid after all the ammonia is given off; I allow the
mixture to settle, and if it is not sufficiently liquid I add more water.
When the liquid has become quite clear I run it off by means of a
syphon and add enough carbonate of potassa to precipitate the lime
in solution, and so obtain a solution of ferrocyanide of potassium, which
I crystallize out by evaporation; or I add to the lime solution sulphuric

page_text: or hydrochloric acid, and a proto or per salt of iron or both; or what
has the same effect a proto-salt of iron, and subsequently chloride of
lime, in either of which cases Prussian blue is thrown down, which I
then wash and dry for sale; or I convert the Prussian blue so produced
into ferrocyanide of potassium by the addition of caustic potassa. The
oxide of iron which remains after the lime and water treatment above
described I fit to be re-used for purifying coal gas by adding to it
sulphate of iron, which combines with the excess of lime left in the
oxide, forming oxide of iron and sulphate of lime. The oxide may be
dried if requisite. When it is not desired to re-use the spent oxide of
iron which has been used for the purification of coal gas, I prepare it
to be burnt in the manufacture of sulphuric acid by washing it with a
strong solution of sulphur in bi-sulphide of carbon, using by preference
for this purpose an apparatus such as herein-before described. By this
means I separate tar and other impurities, which if left in the oxide
cause a large expenditure of nitre in producing sulphuric acid from it.
'Also, when sulphur is separated from spent oxide of iron by means of
naptha, mineral oils, benzole, or turpentine, the sulphur remains much
contaminated with the solvent, I according to my Invention remove
this contamination by treating it with bi-sulphide of carbon or a solution
of sulphur in that liquid. I recover the bi-sulphide of carbon by
distillation whenever in the above processes I obtain a mixture of
naptha, mineral oils, benzole, or turpentine and bi-sulphide of carbon.
In witness whereof, I, the said Benjamin Edward Reina Newlands,
have hereunto set my hand and seal, this Sixteenth day of
September, in the year of our Lord One thousand eight hundred
and sixty-eight.
BENJ. NEWLANDS. (L.S.)