Improvements in the Electro Deposition of Aluminium.
Year: 1894

page_text: Date of Application, 1st Mar., 1894
Complete Specification Left, 30th Nov., 1894-Accepted, 5th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Electro Deposition of Aluminium..
J, ALFRED HINTON HARRIS, trading as Benjamin Harris, of 50 Albion Street,
in the City of Birmingham, Nickel Plater, do hereby declare the nature of this
invention to be as follows:-
This invention consists of the hereindescribed improvements in the electro
deposition of aluminium on other metals or alloys or on other substances.
In carrying out my invention I first prepare a nitrate of aluminium which can
conveniently be done by digesting aluminium metal with gentle heat in strong
nitric acid; or the nitrate of aluminium may be prepared in other ways. To this
nitrate of aluminium solution I add strong ammonia so long as a precipitate is
formed.
In a separate vessel I prepare a hot saturated solution of bisulphite of soda
about from thirty to forty times the bulk of the nitrate of aluminium solution
first above described.
I mix the said two solutions together slowly stirring the same and boil them for
about one hour and I allow the solution thus formed to cool and settle and then
after pouring off the upper clearer part of the liquid I add sufficient ammonia to
the remainder to turn red litmus paper blue.
I use this solution in a bath such as used for electro plating with a strong
electric current obtained from battery or dynamo and I prefer to use double
aluminium anodes so as to deposit the aluminium all round the article which is
being electro plated.
Dated this 28th day of February 1894.
JUMI LIE
DEBOLTIVATION.
Improvements in the Electro Deposition of Aluminium.
I, ALFRED HINTON HARRIS trading as Benjamin Harris, of 50 Albion Street,
in the City of Birmingham, Nickel Plater, 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 :—
This invention consists of the hereindescribed improvements in the electro
deposition of aluminium on other metals or alloys or on other substances.
In carrying out my invention I first prepare a nitrate of aluminium which can
conveniently be done by digesting aluminium metal with gentle heat in strong
nitric acid; or the nitrate of aluminium may be prepared in other ways as well
known. To this nitrate of aluminium solution I add strong ammonia so long as a
precipitate is formed.
In a separate vessel I prepare a hot saturated solution of bisulphite of soda
about from thirty to forty times the bulk of the nitrate of aluminium solution
first above described.

page_text: I mix the said two solutions together slowly stirring the same and boil them for
about one hour and I allow the solution thus formed to cool and settle and then
after pouring off the upper clearer part of the liquid I add sufficient ammonia to
the remainder to turn red litmus paper blue.
I use this solution in a bath such as used for electro plating with a strong
electric current obtained from battery or dynamo and I prefer to use double
aluminium anodes so as to deposit the aluminium all round the article which is
being electro plated, and before using the bath I find it is an advantage to add a
little cyanide of potassium thereto in the proportion of say about two or three
ounces of cyanide of potassium to a bath containing say from thirty to forty
gallons.
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 :-
1. The hereindescribed improved solution for use in the electro deposition of
aluminium the said solution being made from nitrate of aluminium, ammonia and
bisulphite of soda combined together and treated in the manner substantially as
herein set forth.
2. In the electro deposition of aluminium on metals or alloys or other substances
the employment, in combination with the aluminium anodes in an electro plating
bath, of the hereindescribed improved solution made from nitrate of aluminium,
ammonia and bisulphite of soda combined together and treated in the manner
substantially as bereinbefore described and either with or without the addition of
a little cyanide of potassium as set forth.
Dated this 29th day of November 1894.
CHARLES BOSWORTH KETLEY,
Agent for the Applicant.