An Improved Method of Enriching Phosphated Chalk and other Calcareous Phosphates.
Year: 1890

page_text: Date of Application, 21st Nov., 1890
Complete Specification Left, 20th Aug., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
An Improved Method of Enriching Phosphated Chalk and other
Calcareous Phosphates.
I. LÉON CHARLES DELAHAYE, of 23, Rue Leblanc, Paris, in the Republic
of France, Chemist, do hereby declare the nature of this invention to be as
follows
This invention relates to a method of enriching phosphated chalk and other
calcareous phosphates.
For suitably attacking calcareous phosphate I have heretofore first introduced it
into a furnace in order to transform the carbonate of lime which it contains into
caustic lime, then after slaking this lime to obtain it in the form of a fine powder,
I have caused it to be attacked by a solution of more or less concentrated
hydrochlorate of ammonia. In this attack the lime set free by the calcination
is dissolved in the sal-ammoniac, and the ammoniacal gasis set free. I find that
for this purpose any other ammoniacal salt especially the nitrate and acetate, can
be used, provided that the radical of acid of the ammoniacal salt employed gives
with the lime a salt which is practically soluble in water; thus ammonium
sulphate has not appeared suitable, considering the slight solubility of the sulphate
of lime.
Similar results are obtained with the compound ammonium salts, which act like
the corresponding ammoniacal salts, and which can in any case be substituted for
them. The following observations apply therefore also to ammonia compounds
In the attack of the
whatever may be its composition, and likewise to ammonia.
lime a disengagement of ammoniacal gas takes place and this gas being dissolved
in a solution of calcium chloride derived from a previous attack, I have applied
heat until the distillation of the ammonia takes place for attacking the lime; but
I find that the operation can be very well effected by the cold way, and carry out
operations as hereinafter set forth.
It is in the first place expedient to carefully slake the phosphated lime so as
to obtain it in the form of a very fine powder. For obtaining this result it is
necessary to heat the furnaces so as to produce a baking action whilst avoiding the
partial fusion of the material which would cause deposits in the furnace.
The furnaces employed are constructed for capturing the gas and are similar to
those employed in the manufacture of sugar. With these furnaces a phosphated
chalk can be obtained which when soaked with water swells very well and becomes
reduced to an impalpable powder.
This powder is caused to digest in closed bacs provided with agitators, together
with the solution of ammoniacal salt. The reaction takes place in the cold state.
Calcium chloride is formed together with caustic ammonia which remains in
solution. When the reaction is terminated the solution is decanted and passed
to filter presses or any kind of filter. The phosphate not attacked remains upon
the filter whilst the liquid which flows contains the calcium chloride and ammonia.
The filtered material is washed for removing the last traces of ammonia and
chloride and in order not to have too weak solutions it will be advantageous to
carry out methodic washing operations as well in the filters as in the apparatus for
the reaction, wherein an ammoniacal solution partly transformed into caustic
ammonia is caused to pass upon fresh lime which will enable the operation to be
hastened; and according to the same principle the lime already partly enriched is
brought in contact with solutions which are rich in ammouiacal salt.
The solution coming from the filters and containing an ammoniacal solution of
calcium chloride is subjected in a closed apparatus to a current of carbonic acid

page_text: captured upon the calcination furnaces. Carbonate of lime is then precipitated
and the original ammoniacal salt is again formed. After this filtering is effected
the cakes are washed and the solution obtained is used in the further operation.
It will be understood that any suitable apparatus may be employed for carrying
these operations into effect.
Dated this 21st day of November 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Method of Enriching Phosphated Chalk and other
Calcareous Phosphates.
I, LEON CHARLES DELAHAYE, of 23, Rue Leblanc, Paris in the Republic of
France, Chemist, 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 method of enriching phosphated chalk and other
calcareous phosphates.
For suitably attacking calcareous phosphate I have heretofore first introduced
it into a furnace in order to transform the carbonate of lime which it contains into
caustic line, then after slaking this lime to obtain it in the form of a fine powder,
I have caused it to be attacked by a solution of more or less concentrated hydro-
chlorate of ammonia. In this attack the lime set free by the calcination is
dissolved in the sal-ammoniac, and the ammoniacal gas is set free.
I find that for
this purpose any other ammoniacal salt especially the nitrate and acetate, can be
used, provided that the radical of acid of the ammoniacal salt employed gives with
the lime a salt which is practically soluble in water; thus ammonium sulphate has
not appeared suitable, considering the slight solubility of the sulphate of lime.
Similar results are obtained with the compound ammonium salts, which act like
the corresponding ammoniacal salts, and which can in any case be substituted for
them. The following observations apply therefore also to ammonia compounds
whatever may be its composition. In the attack of the lime a disengagement of
ammoniacal gas takes place this gas being dissolved in a solution of calcium
chloride derived from a previous attack. I have applied heat until the distillation
of the ammonia takes place for attacking the lime, but I find that the operation
can be very well effected by the cold way and carry out the operations as herein-
after set forth.
It is in the first place expedient to carefully slake the phosphated lime so as to
obtain it in the form of a very fine powder. For obtaining this result it is
necessary to heat the furnaces so as to produce a baking action whilst avoiding the
partial fusion of the material which would cause deposits in the furnace.
The furnaces employed are constructed for collecting the gases and are similar
to those employed in the manufacture of sugar. With these furnaces a phosphated
chalk can be obtained which when soaked with water swells very well and becomes
reduced to an impalpable powder.
This powder is caused to digest in closed backs provided with agitators, together
with the solution of ammoniacal salt. The reaction takes place in the cold state
and as a result of this reaction calcium chloride is formed together with caustic
ammonia which remains in solution, in case use is made of chlorhydrate of ammonia.
If nitrato or azotate of ammonia were used the reaction would produce nitrate or
azotate of lime which is sufficiently soluble for the operation to be practicable.
When the reaction is terminated the solution is decanted.and passed to filter-presses
or any kind of filter. The phosphate not attacked remains. upon the filter, whilst
the liquid which flows contains the calcium chloride and ammonia. The filtered
material is washed for removing the last traces of ammonia and chloride, and in
:

page_text: order not to have too weak solutions it will be advantageous to carry out methodic
washing operations as well in the filters as in the apparatus for the reaction
wherein an ammoniacal solution partly transformed into caustic ammonia is caused
to pass upon fresh lime which will enable the operation to be hastened; and
according to the same principle the lime already partly enriched is brought in
contact with solutions which are rich in ammoniacal salt.
The solution coming from the filters and containing an ammoniacal solution of
calcium chloride is subjected in a closed apparatus to a current of carbonic acid
captured upon the calcination furnaces. Carbonate of lime is then precipitated and
the original ainmoniacal salt is again formed. After this filtering is effected the
cakes are washed and the solution obtained is used in the further operation.
It will be understood that any suitable apparatus may be employed for carrying
these operations into effect.
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 :-
First. The application, for the purpose of enriching phosphated chalk transformed
into lime by calcination, of any ammonia salt.
Second. The herein described process consisting in attacking in the cold state
phosphated lime calcinated and slaked with water, by an ammonia salt giving a salt
of lime which is soluble in water.
Third. The method of recovering the ammonia salt employed by treating with
carbonic acid, the ammoniacal solution of the corresponding salt of lime.
Fourth. The substitution for the ammonia of any kind of ammonia compounds,
such as methylamines, ethylamines, whatever may be their formula and con-
stitution.
Dated this 20th day of A noust 1801
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.