Improvements in and relating to the Utilisation of Waste Pickle from Tinning and Galvanising Works where Hydrochloric Acid is Used in the Process of Pickling.
Year: 1888

page_text: Date of Application, 29th Sept., 1888
Complete Specification Left, 1st Jan., 1889
Complete Specification Accepted, 23rd Feb., 1889
Improvements in and relating to the Utilisation of Waste Pickle
from Tinning and Galvanising Works where Hydrochloric Acid
is Used in the Process of Pickling.
I, HENRY JAMES KIRKMAN of the Landore Alkali Works, Swansea, Analytical
Chemist, do hereby declare the nature of this invention to be as follows:-
In accordance with my invention, to the waste pickle (consisting of Chloride of
milk of lime "
iron and free Hydrochloric Acid) I add a sufficient quantity of
or of magnesia to neutralise the free acid and precipitate the iron in the form of
an oxide. The oxide of iron is now filtered off by any suitable means and can
then be employed either with or without sawdust for the purification of illuminating
gas; or, said oxide, of iron may be employed in the manufacture of paints, or for
any other purpose in which oxide of iron is used.
The Calcium Chloride formed by the combination of Chlorine with the lime may
be utilised in the recovery of the chlorine, by any of the usual methods.
Should magnesia be employed to precipitate the iron, the solution of chloride of
magnesium may be evaporated to dryness and ignited in a suitable furnace and
the chlorine thus recovered.
Dated this Twenty ninth day of September 1888.
JAMES STEVENSON, ·
Gray's Inn Chambers,
20, High Holborn, London, W.C.,
Agent for Applicant.

page_text: Improvements in and relating to the Utilisation of Waste Pickle
from Tinning and Galvanising Works where Hydrochloric Acid
is Used in the Process of Pickling.
I,. HENRY JAMES KIRKMAN, of the Landore Alkali Works, Swansea, Analytical
Chemist, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My Invention has reference to a cheap and efficient method of utilising the waste
pickle from tinning works where Hydrochloric acid.is used in the process of pickling,
with the object in view, of recovering the chloride of iron, in the form of an oxide,
for employment in the manufacture of pigments, the purification of illuminating gas,
and for other similar purposes.
In accordance with my Invention. I proceed as follows:-To the waste pickle
(consisting of Chloride of iron and free Hydrochloric acid) I add a sufficient quantity
of milk of lime" to neutralise the free acid, and precipitate the iron in the form of
an oxide. The oxide of iron is now filtered off by any suitable means, and can then
be employed either with or without sawdust for the purification of illuminating gas;
or, said oxide of iron may be employed in the manufacture of pigments, or for any
other purpose in which oxide of iron is used.
The Calcium Chloride, formed by the combination of Chlorine with the lime, may
be utilized to recover the Chloriue by any of the usual methods.
Having now particularly described and ascertained the nature of my said Inven.
tion, and in what manner the same is to be performed, I wish it to be understood
that with reference to the employment of magnesia (referred to in my Provisional
Specification) as an alternative medium for the precipitation of the oxide of iron,-
as I am aware it has already been proposed, prior to the date of my Invention, to
employ this substance as a means for the recovery of the Hydrochloric acid from the
liquid acid residues obtained as a bye product in cleaning iron previous to galvanising,
I make no claim in respect thereof, nor do I lay any claim to the employment of a
mixture of magnesia and lime ;. but, what I do claim, and desire to secure by Letters
Patent is
In the utilisation of waste pickle from tinning works (consisting of Chloride of
iron and free Hydrochloric acid) the employment of "milk of lime" to neutralize
the free acid and to recover the chloride of iron therefrom in the form of an oxide
for use in the manufacture of pigments, the purification of illuminating gas, or for
other purposes where oxide of iron is employed, substantially as herein set forth.
Dated this 31st day of December 1888.
JAMES STEVENSON,
20, High Holborn, London, W.C.,
Agent for Applicant.