Improvements in Galvanizing Iron and in Utilizing the Waste Acids therefrom.
Year: 1889

page_text: Date of Application, 12th June, 1889
Complete Specification Left, 12th Mar., 1890-Accepted, 19th Apr., 1890
PROVIDIONAL DIDIFICATION.
Improvements in Galvanizing Iron and in Utilizing the Waste
Acids therefrom.
I, ALFRED GRIFFITHS GREENWAY M.D. Walton Bury Stafford Physician do hereby
declare the nature of this invention to be as follows:-
I. The iron to be galvanized is first treated with muriatic or sulphuric acids in
order to clean its surfaces from oxides &c. A solution of ferrous chloride, or ferrous
sulphate is formed according to the acids employed respectively in a suitable
"tank."
"
II. This solution of ferrous chloride or ferrous sulphate is placed into another
suitable tank and saturated with a solution of ammonium sulphide obtained from
gas works. The ammonium sulphide combines with the ferrous chloride or ferrous
sulphate to form ammonium chloride or sulphate in solution, and ferrous sulphide
precipitated and separated if necessary.
III. The cleaned iron is then immersed in this "tank" containing a solution of
ammonium chloride or sulphate aforesaid which may remain cold or heated with
steam if thought advisable. The iron is then removed and dipped into the molten
zinc or spelter and is galvanized.
IV. The solution of ammonium chloride or sulphate and precipitated ferrous
sulphide may be separated by filtration or by any other convenient method and the
solution of ammonium chloride or sulphate evaporated to form the commercial salt
of ammonium chloride or sulphate.
Dated this 12th day of June 1889.
FREDK. WALKER & HYDE,
4, Little Moorfields, London, E.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Galvanizing Iron and in Utilizing the Waste
Acids therefrom.
I, ALFRED GRIFFITHS GREENWAY M.D. of Walton Bury in the County of Stafford,
Physician 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 relates to improvements in galvanizing iron, and has for its object
the utilization of the waste acids used in the process.
In carrying my invention into effect the iron to be galvanized is first treated with
either hydrochloric or sulphuric acid in order to clean the surface thereof from oxides
and the like. A solution of ferrous chloride, Fe Cl₂, or ferrous sulphate Fe SO, is
thus formed, according to which of the above named acids is employed, and said
solution is retained in a suitable tank or receptacle during the first part of the
process, and is then transferred to a second tank or the like, in which a solution of
ammonium sulphide NH, HS is added to saturation. This latter ingredient is the
ordinary residual product as obtained from gas works. The ammonium sulphide
combines with the ferrous chloride, or ferrous sulphate as the case may be, according
to the kind of acid used in the first part of the process, and ammonium chloride, NH, CI,
or ammonium sulphate 2 NH, SO, is thus formed, and ferrous sulphide Fe S is
precipitated, and may be separated when required.
The iron which is to be galvanized having been cleaned by the first process herein-
before described, is then immersed in the solution of ammonium chloride or sulphate

page_text: in the second tank or receptacle, and this may be heated, or may be used cold as
may be most desirable. The iron is then removed from the second tank and is
immersed in the melted zinc or spelter, and becomes thereby covered by a coating
of metal, or is galvanized, according to the general meaning of this term when used
in this sense.
The solution of ammonium chloride or sulphate in the second tank and the
precipitated ferrous sulphide may be separated by filtration, or by any other
convenient method, and said solution of ammonium chloride or sulphate may then
be evaporated to form the commercial salts of ammonium, either chloride or sulphate
according to the kind of acid used in the first process.
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:
The improved process for galvanizing iron, and for the utilization of the waste
acids and products substantially as herein described.
Dated this 10th day of March 1890.
FREDK. WALKER & HYDE,
4, Moorfields, Fore Street, London, E.C., Agents for the Applicant.