Process of Manufacture of Potassic and Sodic Hydrates and of Bye Products.
Year: 1889

page_text: Date of Application, 28th Mar., 1889
Complete Specification Left, 21st Dec., 1889-Accepted, 8th Feb., 1890
PROVISIONAL SPECIFICATION.
Process of Manufacture of Potassic and Sodic Hydrates and of Bye
Products.
I, GEORGES AUGUSTE HONORÉ GABET, of 88 rue de Richelieu, Paris, in the
Republic of France, Gentleman, do hereby declare the nature of this invention to he
as follows:-
My invention has for its object the manufacture of potassic and sodic alkalies by
the aid of phosphate of lime and of the sulphates of these bases.
The following is a description of my method of operation :-
-
I place an acid solution of phosphate of lime in an enamelled iron boiler, such
solution being more or less dilute-15 per cent. of acid phosphate being a suitable
strength. I bring and maintain the solution nearly to boiling point and gradually
add an equivalent quantity of either sulphate of potash or sulphate of soda. Soluble
phosphate of potash or phosphate of soda, and insoluble sulphate of lime are thus
formed. I separate the sulphate of lime by filtration. I then precipitate the phos-
phoric acid by milk of lime, and after having separated this new precipitate, I
concentrate the solution of potash or of soda to the desired degree in an iron vessel.
The reaction of the sulphates of potash and of soda upon the acid phosphate of
lime may be effected without heat, but I find it more advantageous to employ heat.
With a very slight increase of cost precipitated phosphate free from iron and
alumina and caustic soda of great purity may be obtained.
For this purpose it is necessary to divide the precipitation of the phosphoric acid
into two parts. First, lime is added to the acid solution of phosphate of soda until
a neutral or slight alkaline reaction takes place; half the phosphoric acid is pre-
cipitated in the form of phosphate of lime and di-sodic phosphate remains in solution.
The precipitate of phosphate of lime is separated. In cooling the di-sodic phosphate
remaining in solution crystallizes, and it is separated from the water of crystallization,
and after being dissolved in warm water the phosphoric acid it contains is precipi-
tated by the addition of the necessary quantity of lime. This second precipitate of
phosphate of lime is free from iron and alumina and the soda remaining in solutio.
is of great purity. It may further be obtained in a perfectly pure state by causing
the phosphate of soda to crystallize several times.
This process of manufacture of soda and of potash has the advantage of permitting
of the employment of the double sulphates of potash, soda and magnesia. By treating
these salts with an equivalent solution of acid phosphate of lime, on one hand acid
phosphate of magnesia and acid phosphates of potash and of soda-all of them
soluble are obtained, and on the other hand sulphate of lime which precipitates
and can be separated is obtained.
By adding to the solution of acid phosphates a sufficient quantity of lime, the
potash and soda remaining in solution may be obtained; further, a part of the
phosphoric acid of the acid phosphate of magnesia being taken up by the lime, this
acid phosphate is destroyed, and phosphate of magnesia richer in the base than the
acid phosphate, together with phosphate of lime are precipitated, and may be collected.
If it is desired to obtain the phosphate of magnesia separately, before adding the
lime. the solution is rendered alkaline by the addition of potash or soda, which takes
up a part of the phosphoric acid and causes the precipitation of the phosphate of
magnesia, which is then separated. The subsequent addition of lime will enable
the potash and the soda and a precipitate of phosphate of lime to be obtained.
The phosphoric acid might be precipitated until a neutral reaction is effected,
by the use of carbonate of magnesia, which would also cause the precipitation of
phosphate of magnesia.

page_text: The acid solution of phosphate of lime, necessary for carrying out the process
may be obtained from various substances and in various ways, of which the following
is one method:-I take ordinary phosphate of lime free as possible from iron and
alumina and treat it with the desired quantity of sulphuric acid, such quantity varying
as is well known with the different phosphates; it is then diluted with water and
after remaining six hours in contact, the soluble acid phosphate of lime is separated
from the insoluble sulphate of lime by filtration.
Further, if so desired I may add directly to the sulphate of potash and of soda
the necessary quantity of sulphuric acid to combine with the lime of the phosphate in
an insoluble combination, then dilute with water and treat the phosphate of lime for
this solution.
By acting in this manner I obtain immediately a solution of phosphate of potash
or of phosphate of soda containing phosphate of magnesia, if the double salts have
been employed, and only one filtration will be requisite.
This method also enables the advantageous employment of bisulphates; in this
as in the preceding case I add the quantity of sulphuric acid necessary to combine
with the phosphate of line and form an insoluble combination, and the operation is
This produces the advantage that the quantity of
continued as above described.
sulphuric acid required is less..
Dated this 28th day of March 1889.
ALLISON BROS.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Process of Manufacture of Potassic and Sodic Hydrates and of Bye
Products.
I, GEORGES AUGUSTE HONORÉ GABET, of 88 rue de Richelieu, Paris, in the Republic
of France, Gentleman, 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 has for its object the manufacture of potassic and sodic alkalies by
the aid of phosphate of lime and of the sulphates of these bases.
The following is a description of my method of operation :-
Soluble
1 place a solution of acid phosphate of lime in an enamelled iron boiler, such
solution being more or less dilute--15 per cent. of acid phosphate being a suitable
strength. I bring and maintain the solution nearly to boiling point and gradually add
an equivalent quantity of either sulphate of potash or sulphate of soda.
phosphate of potash or phosphate of soda, and insoluble sulphate of lime are thus
formed. I separate the sulphate of lime by filtration. I then precipitate the phos-
phoric acid by milk of lime, and after having separated this new precipitate, I
concentrate the solution of potash or of soda to the desired degree in an iron
vessel.
The reaction of the sulphates of potash and of soda upon the acid phosphate of
lime may be effected without heat, but I find it more advantageous to employ heat.
With a very slight increase of cost precipitated phosphate free from iron and alumina
and caustic soda of great purity may be obtained.
The
For this purpose it is necessary to divide the precipitation of the phosphoric acid
into two parts. First, lime is added to the solution of acid phosphate of soda until a
neutral or slight alkaline reaction takes place; half the phosphoric acid is precipitated
in the form of phosphate of lime and di-sodic phosphate remains in solution.
precipitate of phosphate of lime is separated. In cooling the di-sodic phosphate
remaining in solution' crystallizes, and it is separated from the water of crystallization,
and after being dissolved in warm water the phosphoric acid it contains is precipitated
by the addition of the necessary quantity of lime. This second precipitate of phosphate
of lime is free from iron and alumina and the soda remaining in solution is of great

page_text: purity. It may further be obtained in a perfectly pure state by causing the phosphate
of soda to crystallize several times
By
This process of manufacture of soda and of potash has the advantage of permitting
of the employment of the double sulphates of potash, soda and magnesia.
treating these salts with an equivalent solution of acid phosphate of lime, on one
hand acid phosphate of magnesia and acid phosphates of potash and of soda-all of
them soluble-are obtained, and on the other hand sulphate of lime which precipitates
and can be separated is obtained.
By adding to the solution of acid phosphates a sufficient quantity of lime, the
potash and soda remaining in solution may be obtained; further, a part of the
phosphoric acid of the acid phosphate of magnesia being taken up by the lime, this
acid phosphate is destroyed and phosphate of magnesia richer in the base than the
acid phosphate, together with phosphate of lime are precipitated, and may be collected.
If it is desired to obtain the phosphate of magnesia separately, before adding the
lime the solution is rendered alkaline by the addition of potash or soda, which takes
up a part of the phosphoric acid and causes the precipitation of the phosphate of
magnesia, which is then separated. The subsequent addition of lime will enable the
potash and the soda and a precipitate of phosphate of lime to be obtained.
The phosphoric acid might be precipitated until a neutral reaction is effected, by
the use of carbonate of magnesia, which would also cause the precipitation of phosphate
of magnesia.
The solution of acid phosphate of lime, necessary for carrying out the process may
be obtained from various substances and in various ways, of which the following is
one method I take ordinary phosphate of lime free as much as possible from iron
and alumina and treat it with the desired quantity of sulphuric acid, such quantity
varying as is well known with the different phosphates; it is then diluted with water
and after remaining six hours in contact, the soluble acid phosphate of lime is
separated from the insoluble sulphate of lime by filtration.
Further, if so desired I may add directly to the sulphates of potash and of soda the
necessary quantity of sulphuric acid to combine with the lime of the phosphate in an
insoluble combination, then diluto with water and treat the phosphate of lime with
this solution.
By acting in this manner I obtain immediately a solution of phosphate of potash
or of phosphate of soda containing phosphate of magnesia, if the double salts have
been employed, and only one filtration will be requisite.
This method also enables the advantageous employment of bisulphates; in this as in
the preceding case I add the quantity of sulphuric acid necessary to combine with the
phosphate of line and form an insoluble combination, and the operation is continued
as above described. This produces the advantage that the quantity of sulphuric acid
required is less.
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 manufacture of caustic potassic and sodic alkalies by the aid of phosphate of lime
and the sulphates or bisulphates of potash and of soda, such process enabling phosphate
of magnesia to be obtained as a bye product when double salts which contain magnesia
as one of the bases are employed.
Datal this 10th day of December 1889
ALLISON BROS.,
Agents for the Applicant.