IMPROVEMENTS IN THE MANUFACTURE T man DIDINA MIAST OF CO
Year: 1870

page_text: LETTERS PATENT to William Marriott, of Huddersfield, in the County
of York, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
T
man DIDINA MIAST OF CO "
Sealed the 15th November 1870, and dated the 9th July 1870.
PROVISIONAL SPECIFICATION left by the said William Marriott at
the Office of the Commissioners of Patents, with his Petition, on
the 9th July 1870.
I, WILLIAM MARRIOTT, of Huddersfield, in the County of York, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF IRON SALTS OR COMPOUNDS, AND IN THE PURIFICATION OF
GAS," to be as follows:-
This Invention has for its object improvements in the manufacture
of iron salts or compounds, and in the purification of gas.
Heretofore the usual method of making iron alum has been to use
copperas (proto-sulphate of iron), adding thereto one equivalent of sul-

page_text: phuric acid for every two equivalents of copperas. Then the proto-
oxide of iron contained therein is converted into peroxide by the
addition of nitric acid, and to the solution of sulphate of peroxide of iron
so obtained the requisite quantity of sulphate of ammonia or sulphate of
potash to convert it into iron alum is added.
According to my Invention I take hydrated peroxide of iron in a
powdered state, either native or artificially precipitated, and add to the
same the quantity of sulphuric acid requisite to bring the iron into the
state of persulphate. I thoroughly mix the materials, and so obtain a
dry powdery product, consisting mainly of persulphate of iron. I treat
this product with water, and so obtain a liquor, to which I add sulphate
of ammonia or sulphate of potash, and then crystallize the iron alum
from the solution of the mixed salts. The dry powdery product first
obtained I employ in gas purifiers for extracting ammonia and sulphur
from coal gas, and for this purpose I mix it with breeze or sawdust, in
order that the gas may be able to pass through it more freely than it
otherwise could. The dry powdery product is also useful in dyeing,
a solution being made from it as for the manufacture of iron alum.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Marriott in the Great Seal Patent Office
on the 7th January 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MARRIOTT, of Huddersfield, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of July, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Marriott, Her special license
that I, the said William Marriott, my executors, administrators, and
assigns, or such others as I, the said William Marriott, 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

page_text: Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF IRON SALTS OR COMPOUNDS, AND IN THE PURIFICATION: OF GAS," upon
the condition (amongst others) that I, the said William Marriott, my
executors or administrators, 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 William Marriott, 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 the manufacture of
iron salts or compounds, and in the purification of gas.
Heretofore the usual method of making iron alum has been to use
copperas (protosulphate of iron), adding thereto one equivalent of
sulphuric acid for every two equivalents of copperas. Then the proto-
oxide of iron contained therein is converted into peroxide by the
addition of nitric acid, and to the solution of sulphate of peroxide of
iron so obtained the requisite quantity of sulphate of ammonia or
sulphate of potash to convert it into iron alum is added.
According to my Invention I take hydrated peroxide of iron in a
powdered state, either native or artificially precipitated, and add to the
same the quantity of sulphuric acid requisite to bring the iron into the
state of persulphate. I thoroughly mix the materials, and so obtain a
dry powdery product consisting mainly of persulphate of iron. I treat
this product with water, and so obtain a liquor, to which I add sulphate
of ammonia or sulphate of potash, and then crystallize the iron alum
from the solution of the mixed salts. The dry powdery product first
obtained I employ in gas purifiers for extracting ammonia and sulphur
from coal gas, and for this purpose I mix it with breeze or sawdust in
order that the gas may be able to pass through it more freely than it
otherwise could. The dry powdery product is also useful in dyeing, a
solution being made from it as for the manufacture of iron alum.
In order that my said Invention may be most fully understood and

page_text: readily carried into effect I will proceed to describe more in detail the
manner in which I prefer to conduct the operations.
I take hydrated peroxide of iron, either native or artificially produced,
such, for instance, as the Irish bog, or Northampton brown ore, or the
peroxide of iron precipitated in the reduction of copper in the wet way;
these I grind, where necessary, and pass through a sieve of about
twenty meshes to the lineal inch. I prefer ores containing not less than
fifty per cent. of peroxide.
Having made an analysis to ascertain the quantity of peroxide
contained in the ore or material, I add for every eighty pounds of per-
oxide of iron one hundred and seventy-four pounds of sulphuric acid,
S. G. 1730, or 146° Twaddle. Supposing the material is found to contain
sixty per cent. of peroxide I take four hundred pounds of the powder
and place it in the hollow of a floor made for that purpose, and add to it
five hundred and twenty pounds sulphuric acid, S. G. 1730. Two men
now intimately mix the acid with the oxide; the mass, if the ore used is
porous like the Irish bog ore, soon changes from the semi-liquid to the
solid form, swells up a little, and the temperature suddenly rises, and
after a few moments jets of vapour issue from the surface; this is
allowed to go on for a short time, when the mass is shovelled to the
heap, and finally when cold it becomes a dry powdery substance. If
the dense oxides, such as the Northampton ore, be used the action is
sluggish, and the material takes a longer time to pass into the powdery
state. When using acid S. G. 1730 the ore or material should be dried
to insure a powdery product if it contains above fifteen per cent.
moisture. I call this powder crude persulphate of iron.
For making iron alum I take the above crude persulphate and
introduce it into a cistern along with water. I blow in steam and
dissolve out the sulphate of peroxide, making a solution of about fifty
degrees Twaddle. I am careful in dissolving the crude peroxide to keep
an excess of fresh oxide to insure a perfect saturation of the acid with
the oxide. I now allow the solution to settle, then draw it into another
cistern heated with a coil of steam pipes, and evaporate until it stands
when hot seventy degrees Twaddle. I then add the equivalent pro-
portion of sulphate of ammonia or potash to convert it into iron alum.
If sulphate of ammonia be employed it should be in the proportion of
sixty-six parts to eighty parts of peroxide of iron in the solution. If

page_text: sulphate of potash be used it should be in the proportion of eighty-seven
parts. I stir well until all is dissolved, and concentrate the solution to
eighty-five degrees Twaddle, then cover over the cistern and allow the
liquor to settle until next day, and run it into vessels to crystallize.
For gas purification I take the powdery crude persulphate of oxide
of iron, and either in this state or mixed with a small quantity of
sawdust or breeze I place it in the dry lime purifiers; all the ammonia
contained in the gas is separated in passing up through the powdery per-
oxide. As soon as the acid previously in combination with the peroxide
of iron combines with ammonia the peroxide contained therein takes
up its equivalent of sulphur. The persulphate of peroxide of iron thus
fixes and separates both ammonia and sulphur from coal gas. When
the gas passing up through the material shews the presence of ammonia
it is shut off. The material when discharged from the purifiers becomes
hot on exposure to the air, revivifies, and is again converted into
hydrated peroxide of iron. To this revivified material I can again add
one hundred and seventy-four pounds sulphuric acid S. G. 1730, for
every eighty pounds peroxide contained in the material, and again
expose the mixture to the gas to abstract the ammonia therefrom. The
sulphate of ammonia can be washed out of the material and salted down
or crystallized. The peroxide left in the vats can be used again to mix
with sulphuric acid, or the oxide so left may be used without further
addition of acid for the separation of sulphuretted hydrogen.
The quantity of crude persulphate put on the sieves of the purifiers
should be so regulated as not too much to obstruct the passage of the
gas. Sawdust or breeze mixed with the persulphate will enable the gas
to pass more freely.
I also use the solution of the persulphate for dyeing, and for this
purpose take the crude persulphate of peroxide of iron, dissolve it in
water with free steam, being careful to have some ground peroxide in
excess to insure the saturation of the sulphuric acid; I then allow the
solution to settle, draw it off into another vessel, evaporate until the
solution stands when cold at from seventy-five to eighty degrees
Twaddle; in this state it is used for dyeing.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that what
I claim is,―

page_text: Third. The purification of gas, substantially as described.
In witness whereof, I, the said William Marriott, have hereunto 5
set my hand and seal, this Thirtieth day of December, in the year
of our Lord One thousand eight hundred and seventy.
WILLIAM MARRIOTT. (L.S.)