IMPROVEMENTS IN THE MANUFACTURE OF HYDRATE SULPHATE AND OTHER SALTS OF ALUMINA
Year: 1885

page_text: HUBERT RICHARDSON Paper & Chemical Manufacturer Monkton Lodge Jarrow-
on-Tyne does hereby declare the nature of bis invention for IMPROVEMENTS
IN THE MANUFACTURE OF HYDRATE SULPHATE AND OTHER SALTS OF ALUMINA
to be as follows:-
In the
The object of this invention is the manufacture of Hydrate of Alumina free from
impurities more especially from iron-The acetate sulphate or other salts of
alumina being obtained from this hydrated alumina in the usual manner.
first place I heat bauxite or other mineral containing alumina with hydrochloric
acid which dissolves the alumina iron & lime of the mineral. After settling the
insoluble from the soluble portions I heat the solution with one of the known
reducing agents for the purpose of transforming the per-chloride of iron into proto-
chloride of iron I prefer for this purpose to use hypo-sulphite of soda. I then heat
the clear solution with carbonate of lime (preferably in the form of a milk of
chalk) or a carbonate of one of the other alkaline earths when the Hydrate of
Alumina is precipitated, the iron & lime remaining in solution. The precipitated
Hydrate of Alumina is separated from the solution either by decantation or by a
filter press. The Hydrate of Alumina may be dried for use as such or dissolved in
sulphuric, acetic or other acid for the manufacture of pure sulphate or other salts
of Alumina or used for the manufacture of other preparations of Alumina.
.
11
J

page_text: other Salts of Alumina.
HUBERT RICHARDSON Paper & Chemical Manufacturer Monkton Lodge Jarrow-
on-Tyne does hereby declare the nature of his invention for IMPROVEMENTS IN THE
MANUFACTURE OF HYDRATE SULPHATE & OTHER SALTS OF ALUMINA 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 this invention, is the manufacture of Alumina & of Hydrate of
Alumina, free from impurities, more especially from iron. The Acetate Sulphate
and other Salts of Alumina being obtained from the Hydrate of Alumina or Alumina,
in the usual manner.
I treat clay bauxite, blast-furnace or other slag or other substances containing
Alumina, in a vessel of stone, or other suitable material, with hydro-chloric acid,
until as much as practicable of the Alumina, together with the iron, lime & other
bases contained in the said substance are dissolved.
After separating the insoluble from the soluble portions, by settling or filtration,
I add a sufficient quantity of any of the known reducing agents, to the clear
solution so obtained, for the purpose of reducing the per-chloride of iron, into
proto-chlorine of iron. I prefer for this purpose to use sulphite of soda, or hypo-
sulphite of soda.
I then treat the clear solution with carbonate of lime (preferably in the form of
milk of chalk) or a carbonate of any of the alkaline earths; when the Hydrate of
Alumina is precipitated, and the iron & lime remain in solution.
The precipitated Hydrate of Alumina, is then separated from the solution by
filtration or by decantation, and the Hydrate of Alumina well washed with water.
The Hydrite of Alumina may be dried for use, as such; or dissolved in Sulphuric,
Acetic or other acid, for manufacture of pure Sulphate Acetate, or other Salt of
Alumina, or used for the manufacture of other preparations of Alumina.
Having now particularly described and ascertained the nature of my said
invention, & in what manner the same is to be performed, I declare that what
I claim is:
1st The freeing Alumina, its Salts & other compounds from iron, by reducing
ferric salts of iron, to ferrous salts of iron & precipitating the alumina with a
carbonate of the alkaline earths.
Dated this 26th day of March 1886.