IMPROVEMENTS IN THE TREATMENT OF THE IRON RESIDUES OBTAINED IN THE PURIFICATION OF COAL GAS, AND IN THE OBTAINING OF PRODUCTS THEREFROM
Year: 1876

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
THE TREATMENT OF THE IRON RESIDUES OBTAINED IN THE PURIFICATION
OF COAL GAS, AND IN THE OBTAINING OF PRODUCTS THEREFROM." A com-
munication from abroad by Hermann Gruneberg, of Kalk, near Cologne, in the
Empire of Germany.
Sealed the 3rd March 1877, and dated the 9th September 1876.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 9th September 1876
"
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. IMPROVEMENTS IN THE TREATMENT OF THE IRON RESIDUES OBTAINED>
IN THE PURIFICATION OF COAL GAS, AND IN THE OBTAINING OF PRODUCTS THERE-
FROM.' A communication from abroad by Hermann Gruneberg, of Kalk, near
Cologne, in the Empire of Germany.
"
This Invention relates to the extraction of certain products which are contained
in what is known as spent oxide of iron, the residual result of the employment of
oxide of iron in the purification of coal gas, and it consists,―
1st. In submitting the before-mentioned spent oxide of iron to the action of
water in order to separate the soluble salts or compounds of ammonia
2ndly. In submitting the before-mentioned residues to a livigating process, or to
such a process as shall by the aid of water eluninate the sawdust usually mixed
with such coal gas purifying agent.
3rd. Also in submitting the residual spent oxide of iron either in its crude or in
its washed condition, as before mentioned, to the action of a solution of a caustic
alkalı, or to the action of an alkaline earth, such, for example, as caustic lime, in
order to obtain the ammonia contained therein.
4th The separation of the solution thus obtained from the insoluble residue and
then submitting it to the action of an acid, for example, hydrochloric acid, in order
that a portion of the sulphur contained therein may be liberated and precipitated
5th. After the sulphur has been deposited the products capable of producing
colors or coloring matters are to be precipitated by the employment of a proto or
other salts or compounds of iron, either alone or in conjunction with an oxidising
agent, such, for example, as chlorido of lime.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 6th
March 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE TREATMENT OF THE IRON RESIDUES OBTAINED
IN THE PURIFICATION OF COAL GAS, AND IN THE OBTAINING OF PRODUCTS THERE-
FROM." A communication from abroad by Hermann Grunoberg, of Kalk, near
Cologne, in the Empire of Germany.
The said Invention relates to the extraction of certain products which are
contained in what is known as spent oxide or oxides of iron, the residual result of
the employment of oxide or of oxides of iron in the purification of coal gas, and it
consists,―
First. In submitting the before-mentioned spent oxide or oxides of iron to the
action of water in order to separate the soluble salts or compounds of ammonia
which have been formed and which are contained therein. The solution thus
obtained containing the salts and compounds of ammonia may then be evaporated
so as to crystallize out the same, or the ammonia may be liberated therefrom and
be obtained by distillation, as is well understood.
2ndly. In submitting to a levigating or washing process, or to such a process as
shall by the aid of water eliminate the sawdust usually mixed with such coal gas
purifying agent or agents.
3rd. In submitting the residual spent oxide or oxides of iron, either in their
crude or in their levigated or washed condition, as before mentioned, to the action
of a solution of a caustic alkali, or to the action of an alkaline earth, such, for
example, as caustic lime, in order that the sulphur contained therein may be
dissolved out and be separated thereform.
4th. Effecting the separation of the solution thus obtained from the insoluble
residue and then submitting it to the action of an acid, for example, hydrochloric
acid, in order that a portion of the sulphur contained therein may be liberated and
be precipitated.
5th. After the sulphur has been deposited the products capable of producing
colors or coloring matters which may be contained in the supernatant or clear
solution are to be precipitated by the employment of a proto or other salts or com-
pounds of iron, either alone or in conjunction with an oxidizing agent, such, for
example, as chloride of lime. Or instead of employing compounds of iron, either
alone or in conjunction with an oxidising agent, the oxidising agent may be
employed after the color compound has been precipitated, and such oxidising agent
may be either chloride of lime, nitric acid, or a mixture of sulphuric and nitric acids,
or chromate of potassium, with an acid, or chromic acid; or other oxidising agents
may be employed.
Having now described and particularly ascertained the nature of the said In-
vention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
First. Submitting what are known as spent oxide or oxides of iron obtained in
effecting the purification of coal gas, and herein referred to, to the action of water,
so as to remove any soluble salts or compounds of ammonia which may have been
separated from the impure coal gas.
Secondly. Submitting the residual mixture of oxide or of oxides of iron to a
levigating or washing process so as to separate any sawdust or other diluting
agent therefrom.
Thirdly. Submitting the spent oxide or oxides of iron either before or subsequent
to their lixiviation or washing to the action of a solution of an alkali or of a caustic

page_text: alkaline earth, such as lime, so as to remove the sulphur therefrom, and to effect the
solution of the salts or compounds capable of producing coloring matters.
Fourthly. Effecting the precipitation of a portion of the sulphur thus separated
by the employment of an acid, and collecting and utilizing the precipitated sulphur
thus obtained.
Fifthly. Precipitating and obtaining by means of compounds of iron, employed
either alone or in conjunction with oxidizing agents, those combinations or products
which with the before-mentioned compounds are capable of forming colors or
pigments.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, this Second day of March, One thousand
eight hundred and seventy-seven.
J. HENRY JOHNSON. (L.S.)