Improvements in and relating to Pickling Iron and Steel Plates and other Articles Previous to Tinning or Galvanizing.
Year: 1893

page_text: Date of Application, 27th May, 1893
Complete Specification Left, 27th Feb., 1894-Accepted, 7th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Pickling Iron and Steel Plates and
other Articles Previous to Tinning or Galvanizing.
I HENRY JAMES KIRKMAN, 3 Carlton Terrace, Swansea, Glamorganshire,
Manager of Chemical Works do hereby declare the nature of this invention to be
as follows:
The object of my improvements is to hasten the pickling process when sulphuric
acid is used as the pickling agent.
This advantage is attained by the addition of a soluble chloride, or of hydro-
chloric acid in sufficient quantity to the pickling bath of sulphuric acid to ensure
sharpening or expediting the action on the plates or other articles. The free
hydrochloric acid (either produced by the decomposition of the chloride or by the
addition of hydrochloric acid) in the sulphuric acid is neutralized by the oxide or
metal of the article being pickled; thus forming a chloride of that metal, which
is then decomposed, by the sulphuric acid present, forming again free hydrochloric
acid and a sulphate of the metal, the hydrochloric acid thus set free is available for
effecting the further solution of the oxide or metal of the article being pickled.
The formation of the chloride of the metal will be continually taking place as long
as there is sufficient free sulphuric acid present to decompose the chloride as it is
formed. When all the sulphuric acid is used up or saturated a fresh pickling
solution is made and the operation carried out again as above described.
Dated this 27th day of May 1893.
JAMES STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C.,
Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Pickling Iron and Steel Plates and
other Articles Previous to Tinning or Galvanizing.
I, HENRY JAMES KIRKMAN, 3 Carlton Terrace, Swansea, Glamorganshire,
Manager of Chemical Works, 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:—
The object of my improvements is to hasten the pickling process when sulphuric
acid is used as the pickling agent.
This advantage is attained by the addition of a soluble chloride, or of hydro-
chloric acid in sufficient quantity, namely say to every 100 cub. feet of sulphuric
acid bath, add 1 to 2 ewt. common salt or its equivalent in any soluble chloride or
hydrochloric acid, to the pickling bath of sulphuric acid, to ensure sharpening or
expediting the action on the plates or other articles. The free hydrochloric acid
(either produced by the decomposition of the chloride or by the addition of hydro-
chloric acid) in the sulphuric acid is neutralized by the oxide or metal of the
article being pickled; thus forming a chloride of that metal, which is then
decomposed, by the sulphuric acid present, forming again free hydrochloric acid,
and a sulphate of the metal; the hydrochloric acid thus set free is available for
effecting the further solution of the oxide or metal of the article being pickled.
[Price 8d.1

page_text: The formation of the chloride of the metal will be continually taking place as long
as there is sufficient free sulphuric acid present to decompose the chloride as it is
formed. When all the sulphuric acid is used up or saturated, a fresh pickling
solution is made and the operation carried out again as above described.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
In pickling iron and steel plates and other articles previous to tinning or
galvanizing, the employment of a soluble chloride or of hydrochloric acid in order
to hasten the pickling process when sulphuric acid is employed as the pickling agent,
as herein set forth.
Dated this 27th day of February 1904
.
JAMES STEVENSON,
1, Furnival Street, E.C., Agent for Applicant.