IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF ALUMINA
Year: 1879

page_text: LETTERS PATENT to Sigmund Baerlein and Maximilian Baerlein, both of
Manchester, in the County of Lancaster, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF SULPHATE OF ALUMINA." A communication from
abroad by Francis Laur, of Paris, in France.
Sealed the 18th April 1879, and dated the 15th January 1879.
PROVISIONAL SPECIFICATION left by the said Sigmund Baerlein and
Maximilian Baerlein at the Office of the Commissioners of Patents on the
15th January 1879.
SIGMUND BAERLEIN and MAXIMILIAN BAERLEIN, both of Manchester, in the
County of Lancaster. "IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE OF
ALUMINA." A communication from abroad by Francis Laur, of Paris, in France.
Our Invention relates to improvements in the manufacture of sulphato of alumina,
and has for its principal object the production of the sulphate of alumina which is
practically if not entirely free from iron and from free acid.
We attain our object by mixing aluminous earths with sulphuric acid and heating
one or both ingredients or the mixture until chemical action takes place when we cool
and dilute with water, and then act upon the solution thus obtained by introducing
a quantity of metallic zinc in any convenient form. The proportion in which the
ingredients are used may be varied considerably, but we prefer certain proportions
by which the best results are obtained; and in order to further elucidate our
Invention we proceed to describe the following process, which may however be
considerably modified and varied without departing from the leading features of our
Invention.
A quantity of diluted sulphuric acid is raised nearly to the boiling point, a quan-
tity of bauxite in the form of powder is then introduced, when chemical action
commences. Water is then added in order to cool and to keep the solution in a
Liquid state, and the whole is then allowed to stand, when the liquid portion inay
be decanted and subjected to the action of zinc for several hours or days according
to the degree of heat at which the solution may be maintained.
The zinc precipitates some or all of the iron and neutralizes all the free acid
contained in the solution. If the proportion of the aluminous matters and the
sulphuric acid be so chosen as to produce a nearly neutral solution then the zinc
will precipitate nearly all the iron contained therein. We usually employ 440lbs.
Duice ANT

page_text: avoirdupois of sulphuric acid of 50° Beaumé, and 220 to 290lbs. avoirdupois of
bauxite (hydrate of alumina), 13 to 14 gallons of water, and 6 to 12lbs. of zinc.
The best result is obtained with a solution which is absolutely neutral and from
Buch the zinc will remove all the iron, but good results may still be obtained with
this process by varying the proportions and also the various manipulations and
their successive order to a considerable extent. The process above described may
be accelerated by passing through the solution an electric current.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sigmund Baerlein and Maximilian Baerloin in the Great Seal
Patent Office on the 14th July 1879.
SIGMUND BAERLEIN and MAXIMILIAN BAERLEIN, both of Manchester, in the
County of Lancaster. "IMPROVEMENTS IN THE MANUFACTURE OF SULPHATE of
ALUMINA." A communication from abroad by Francis Laur, of Paris, in France.
Our Invention relates to improvements in the manufacture of sulphate of alumina,
and has for its principal object the production of sulphate of alumina which is
practically if not entirely free from iron and from free acid.
We attain our object by mixing aluminous earths with sulphuric acid, and heating
one or both ingredients or their mixture until chemical action takes place, when we
cool and dilute with water, and then act upon the solution thus obtained by intro-
ducing a quantity of metallic zinc in any convenient form, and which action we
assist sometimes with an electric current. The liquid is afterwards decanted and may
then be solidified. The proportion in which certain ingredients are used may be
varied considerably, but we prefer using certain proportions, to be named hereafter,
by which the best results are obtained; and in order to further elucidate our
Invention we proceed to describe the following process, which may however be
considerably modified and varied without departing from the leading features of
our Invention.
A quantity of diluted sulphuric acid is raised nearly to the boiling point, a quan-
tity of bauxite in the form of powder is then introduced, and chemical action
commences. Water is then added in order to cool and to keep the solution in a
liquid state, and the whole is then allowed to stand and settle, after which the
liquid portion may be decanted, while the remainder is refuse. Zinc, granulated
or in plates, is then thrown in and allowed to stand for hours or days, according to
the degree of heat at which the solution is kept. The zinc precipitates some or all
of the iron and neutralizes all the free acid contained in the solution, after which
the solution is again decanted, and if solid sulphate of alumina is to be produced
the liquor is concentrated by heat in any convenient manner to about 45° Beaume
(taken hot) and poured into casks. The best result is obtained if the proportion of
earthy matters to sulphuric acid is so chosen as to produce a nearly neutral solution,
in which case nearly all the iron will be precipitated. In addition to the zinc an

page_text: electric current may be passed through the solution in order to accelerate the pre-
cipitation. If after the first chemical attack the mixture is boiled up again the
settlement of the liquor afterwards is thereby hastened.
The proportions which we prefer to use are about as follows:-440 pounds
avoirdupois of sulphuric acid of 50° Beaume, and 220 to 290 pounds avoirdupois of
bauxite (hydrate of alumina), 13 to 14 gallons of water, and 6 to 12 pounds avoir-
dupois of zinc. The proportions will vary according to the quality of the bauxite
employed, which has to be ascertained if the best result is desired, since nearly the
whole of the iron is precipitated in a nearly neutral solution, but good results are
still obtained if the proportions are varied to a considerable extent, nor is the
successive order of the various manipulations of much consequence.
Having now described the nature of our Invention, and ascertained in what
manner the same may be carried out in practice, we declare that we do not limit
ourselves to the exact details given above but claim :-
The use of zinc with or without the assistance of an electric current in tho
manufacture of sulphate of alumina, substantially as set forth.
In witness whereof, I, the said Sigmund Baerlein, on behalf of myself and the
said Maximilian Baerlein, have hereunto set my hand and seal, this Twelfth
day of July, in the year of our Lord One thousand eight hundred and
seventy nine.
Witness,
A. HILDEBRANDT,
Patent Agent,
Manchester.
SIGMUND BAERLEIN. (LS)