Process for Bleaching and Purifying Aluminium Sulphate.
Year: 1891

page_text: Date of Application, 23rd Jan., 1891
Complete Specification Left, 23rd Oct., 1891-Accepted, 28th Nov., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by LA SOCIETÉ ANONYME DES ANCIENNES SALINES
DOMANIALES DE L'EST, of Paris, France.]
Process for Bleaching and Purifying Aluminium Sulphate.
1, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention to be as follows:-
This invention relates to a new process for bleaching and purifying aluminium
sulphate.
It is known that the methods employed up to the present time for removing the
iron contained in aluminium sulphate, consisting in the use of binoxide of manganese,
or of electrolysis, give a yellow product which is unserviceable for certain industrial
processes.
This coloration of aluminium sulphate is due to the presence of foreign substances,
the composition of which has not yet been very exactly defined.
By means of the process which forms the subject of the present invention this
inconvenience is entirely obviated and a very pure product is obtained which can
be employed under very favorable conditions, in dyeing with turkey-red and in
the electrolytic extraction of aluminium.
The said process consists in heating the lyes before or during their concentration
to a temperature near to boiling point, and taking care to maintain a small quantity
of free acid. At the same time, there is added, either a sulphite, bisulphite or
hyposulphite (these salts being by preference of the soda base) or oxygenated
water, or mixtures of binoxide of barium and dilute acids. The lyes are suitably
agitated and the reaction is produced very rapidly even with a small quantity of
reagent.
Dated this 23rd day of January 1891.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process for Bleaching and Purifying Aluminium Sulphate.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Fellow of the Institute of Patent Agents 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 relates to a new process for bleaching and purifying aluminium
sulphate.
It is known that the methods employed up to the present time for removing the
iron contained in aluminium sulphate, consisting in the use of binoxide of manganese,
or of electrolyses, give a yellow product which is unserviceable for certain industrial
processes.
This coloration of aluminium sulphate is due to the presence of foreign substances,
the composition of which has not yet been very exactly defined.
By means of the process which forms the subject of the present invention this
inconvenience is entirely obviated and a very pure product is obtained which can
be employed under very favorable conditions, in particular in dyeing with turkey-
red and in the electrolytic extraction of aluminiuin.
The said process consists in heating the lyes before or during their concentration
Poiss Ad

page_text: to a temperature near to boiling point, and taking care to maintain a small quantity
of free acid. At the same time, there is added, either a sulphite, bisulphite, or
hyposulphite (these salts being by preference of the soda base) or oxygenated
water, or mixtures of binoxide of barium and dilute acids. The lyes are suitably
agitated and the reaction is produced very rapidly even with a small quantity of
reagent.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The process of purifying and decolorising aluminium sulphate consisting in the
introduction into the lyes heated either before or after- their concentration, either
sulphites, bisulphites or hyposulphites, or oxygenated water, or mixture of binoxide
of barium and dilute acids, substantially as described.
Dated this 22nd day of October 1801
ABEL & IMRAY,
Agents for the Applicant.