OBTAINING BY AN IMPROVED METHOD CERTAIN PRODUCTS FROM MATERIALS USED IN THE MANUFACTURE OR PURIFICATION OF GAS
Year: 1858

page_text: by the Act.)
PROVISIONAL SPECIFICATION left by Samuel Boulton at the Office
of the Commissioners of Patents, with his Petition, on the 4th March
1858.
I, SAMUEL BOULTON, of Number 11, Luther Street, Everton, near Liverpool,
in' the County of Lancaster, Agent, do hereby declare the nature of the said
Invention for "OBTAINING BY AN IMPROVED METHOD CERTAIN PRODUCTS FROM
MATERIALS USED IN THE MANUFACTURE OR PURIFICATION OF GAS," to be as
follows:-
My Invention consists in obtaining chemical products from any material
containing oxide of iron, which shall have been used in purifying gas of the
kind commonly used for illuminating purposes. The products which I thus
obtain are ammonia, prussiate of potash, prussiate of soda, prussiate of iron,
(commonly called "Prussian blue") sulphur, and sulphuric acid. Instead of
placing the material in retorts or pots, and fusing the same along with potash,
or carbonate of potash, or sulphate of potash and lime (as I believe has been
attempted for the purpose of obtaining prussiate of potash), the mode I adopt
is as follows:-If the material to be operated on is mixed with wood or saw-
dust, I place the whole in water for the purpose of washing out the same;
I then prefer to grind the material, but this is not absolutely requisite ; it is
then-placed (either in-a ground state or otherwise,) in a solution of carbonate

page_text: of soda or carbonate of potash, sulphate of soda or sulphate of potash, adding
thereto a little lime, if found desirable; I prefer, however, to render the soda
or potash used in the said solution either wholly or partially caustic; I then
usually apply heat and frequent agitation, but these I do not consider
absolutely essential.
The ammonia evolved during this operation may be caught and condensed
by any of the ordinary methods for any desired purpose. When the whole
has been sufficiently operated upon, I run off the solution and allow the same
to subside. Sometimes I find it requisite to add acid (muriatic being preferred)
to throw down any sulphur which may be present in the solution; and, if
requisite, I filter the same. The residuum after being washed is laid aside to
be operated upon in manner herein-after described. The clear solution ob-
tained as above mentioned, I either proceed to crystalize for the production
of prussiate of potash or prussiate of soda, (according as either soda or potash
may have been used,) or else I add thereto a solution of iron (muriate of iron
being preferred) for the. production of prussiate of iron, commonly called
"Prussian blue," which latter may either be disposed of as such, or treated
in the ordinary known method for the production of prussiate of soda or
prussiate of potash. The residuum above mentioned after being washed as
already stated, I dry and place the same in any convenient apparatus for the
purpose of obtaining sulphur therefrom by sublimation, or apply the same in
the manufacture. of sulphuric acid.
In addition to the method above detailed, I sometimes pursue the following
course I apply to the original materials (ground or otherwise) either
muriatic or sulphuric acid, diluting the same with water, if found desirable.
By this means the ammonia is obtained in solution, which may be washed off
and treated as may be desired. This operation is facilitated by the application
of heat. The remaining mass after being washed with water, I place in the
alkaline solution, as herein-before mentioned, and further proceed to operate
thereon for the purposes and in the manner already described.