New or Improved Processes for Converting Natural and other Phosphates into Products Assimilable by Vegetables and into Valuable Sub-products.
Year: 1887

page_text: Date of Application, 5th May, 1887
Complete Left, 24th Jan., 1888
Complete Accepted, 9th Mar., 1888
New or Improved Processes for Converting Natural and other
Phosphates into Products Assimilable by Vegetables and into
Valuable Sub-products.
I, WILLIAM LLOYD WISE of number 46 Lincoln's Inn Fields, in the County of
Middlesex, Consulting Engineer and Patent Agent do hereby declare the nature of
this invention (a communication to me from abroad by Ernest Solvay of 19 Rue du
Prince Albert, Brussels, in the Kingdom of Belgium, Manufacturer,) to be as
follows:-
The following is a description of the nature of the invention communicated to me
by my foreign correspondent.
แ Every natural or other phosphate, whatever be its richness and its composition and
whatever be the first treatments to which it is subjected must finally he converted
into a product which may be used for agricultural purposes that is to say which is
assimilable by plants. Up to the present time only two processes have been employed
for this purpose in the arts and manufactures.
One of the said processes consists in treating the phosphates by means of sulphuric
acid, so as to convert them into superphosphates, the other of the said processes consists
in treating the phosphates by means of hydrochloric acid so as finally to form
precipitated bibasic phosphate of lime.
I have endeavoured to effect other reactions and to obtain other products equally
suitable for agricultural purposes. Silica and alumina act as acids as regards the
powerful bases and they are more fixed than phosphoric acid. If they be placed in
presence of natural and other basic phosphates and if the temperature be carried
sufficiently high, they will displace partially or entirely the phosphoric acid.
I operate as follows:-I mix intimately with the phosphate which is to be decom-
posed, silica or alumina or compounds of natural or other silica and alumina and
especially those kinds having the finest grains and those most easily attacked, in such
quantities (deducting the quantity of these substances which the natural phosphate
may already contain) that the total quantity of silica and alumina will be sufficient to
take up all the bases either free or united to the phosphoric acid. I then heat the
mixture In cases where the mixture is difficult to treat I add thereto fuel to promote
decomposition.

page_text: Two cases may present themselves :—
1. If the temperature has not been carried too high and if it be supposed that the
material operated on is pure tribasic phosphate of lime mixed with pure silicic acid
there will be formed silicate of lime with two equivalents of base and metaphosphate
of lime with the other equivalent. The reaction is greatly promoted if previously
metaphosphate of lime has been added to the said mixture the fusibility of the said
metaphosphate urging on the desired reaction.
Metaphosphate of lime is soluble in citrate of ammonia and may be utilized for
agricultural purposes even in a state of mixture such as it leaves the preceding
reaction.
2. If the temperature has been carried sufficiently high the phosphoric acid is driven
off and collected separately in water or in a dry state in chambers or reservoirs.
In the first case it may be combined with lime or with residuum silicate or
aluminate of lime if it be sufficiently friable so as to obtain assimilable phosphate
of lime.
In the second case it is simply mixed in a dry state with this same residuum or with
lime and it is employed such as it is, for agricultural purposes unless it be desired to
use it as an acid for instance for the manufacture of phosphate of ammonia.
The reactions above mentioned may he combined with the decomposition of sea
salt or chloride of potassium so as to obtain finally assimilable phosphate of lime,
caustic soda or potash and chlorine or hydrochloric acid.
I add to the mixture herein before mentioned chloride of sodium or of potassium
and calcine the whole as herein before described in presence of air or steam.
Chlorine or hydrochloric acid is set free and the residuum contains a soluble
phosphate of soda or of potash. The said soluble phosphate being caustified by lime
gives precipitated bibasic phosphate and a solution of caustic soda or potash.
The reaction apparatus which I use in carrying out these operations are such as are
usually employed in the arts and manufactures and need not be described.
Still I may point out as deserving to have preference, firstly the reverberatory
furnace or the tank furnace known in Belgium under the name of "Four à bassin
used in glass works or else the revolving drum or rotatory furnace used in the manu-
facture of soda by the Leblanc process in the second place the cupola furnace used
in foundries, but after having previously agglomerated the mixture into bricks or
pieces with an intimate mixture of fuel or not.
1 use the forced insufflation of air and even Siemen's and other heat recoverers
when I wish to attain high temperatures easily. If there be phosphorous set free which
however only occurs in reducing atmospheres it is reoxidised subsequently or on
leaving the apparatus and is converted in any way into phosphoric acid."
Dated this 5th day of May 1887.

page_text: New or Improved Processes for Converting Natural and other
Phosphates into Products Assimilable by Vegetables and into
Valuable Sub-products.
I, WILLIAM LLOYD WISE of No. 46 Lincoln's Inn Fields, London, W.C., Consulting
Engineer and Patent Agent do hereby declare the nature of this invention, a com-
munication to me from abroad by Ernest Solvay of 19 Rue du Prince Albert, Brussels,
in the Kingdom of Belgium, Manufacturer, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
The following is a description of the nature of the invention communicated to me
by my Foreign Correspondent.
Every natural or other phosphate, whatever be its richness and its composition and
whatever be the first treatments to which it is subjected must finally be converted into
a product which may be used for agricultural purposes that is to say which is assimilable
by plants. Up to the present time only two processes have been employed for this
purpose in the arts and manufactures. One of the said processes consists in treating
the phosphates by means of sulphuric acid, so as to convert them into superphosphates,
the other of the said processes consists in treating the phosphates by means of hydro-
chloric acid so as finally to form precipitated bibasic phosphate of lime.
I have endeavoured to effect other reactions and to obtain other products equally
suitable for agricultural purposes.
Silica and alumina act as acids as regards the
powerful bases and they are more fixed than phosphoric acid. If they be placed in
presence of natural and other basic phosphates and if the temperature be carried
sufficiently high, they will displace partially or entirely the phosphoric acid.
1 operate as follows: I mix intimately with the phosphate which is to be decom-
posed, silica or alumina or compounds of natural or other silica and alumina and
especially those kinds having the finest grains and those most easily attacked, in such
quantities (deducting the quantity of these substances which the natural phosphato
may already contain) that the total quantity of silica and alumina will be sufficient to
take up all the bases either free or united to the phosphoric acid. I then heat the
mixture In cases where the mixture is difficult to treat I add thereto fuel to promote
decomposition.
Two cases may present themselves :
1. If the temperature has not been carried too high and if it be supposed that the
material operated on is pure tribasic phosphate of lime mixed with pure silicic acid
there will be formed silicate of lime with two equivalents of base and metaphosphate
of lime with the other equivalent. The reaction is greatly promoted if previously
metaphosphate of lime has been added to the said mixture the fusibility of the said

page_text: metaphosphate urging on the desired reactions. Metaphosphate of lime is soluble in
citrate of ammonia and may be utilized for agricultural purposes even in a state of
mixture such as it leaves the preceding reaction.
2. If the temperature has been carried sufficiently high the phosphoric acid is driven
off and collected separately in water or in a dry state in chambers or reservoirs.
In the first case it may be combined with lime or with residium silicate or aluminate
of line if it be sufficiently friable so as to obtain assimilable phosphate of lime.
In the second case it is simply mixed in a dry state with this same residium or with
lime and it is employed such as it is, for agricultural purposes unless it be desired to
use it as an acid for instance for the manufacture of phosphate of ammonia.
The reactions above mentioned may be combined with the decomposition of sea
salt or chloride of potassium so as to obtain finally assimilable phosphate of lime,
caustic soda or potash and chlorine or hydrochloric acid.
I add to the mixture hereinbefore mentioned chloride of sodium or of potassium
and I calcine the whole as hereinbefore described in presence of air or steam.
Chlorine or hydrochloric acid is set free and the residium contains a soluble
phosphate of soda or of potash. The said soluble phosphate being caustified by lime
gives precipitated bibasic phosphate and a solution of caustic soda or potash.
The reaction apparatus which I use in carrying out these operations are such as
are usually employed in the arts and manufactures and need not be described. Still
may point out as deserving to have preference, firstly the reverbatory furnace or
the tank furnace known in Belgium under the name of "Four à bassin" used in glass
works or else the revolving drum or rotatory furnace used in the manufacture of soda
by the Leblanc process-in the second place the cupola furnace used in founderies,
but after having previously agglomerated the mixture into bricks or pieces with an
intimate mixture of fuel or not.
I use the forced insufflation of air and even Siemen's and, other heat recoverers
when I wish to attain high temperatures easily. If there be phosphorous set free
which however only occurs in reducing atmospheres it is reoxidised subsequently or
on leaving the apparatus and is converted in any way into phosphoric acid.
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 industrial processes hereinbefore described for partially or totally liberating
phosphoric acid from phosphate of lime substantially as herein before described or for
partially or totally liberating phosphoric acid from phosphate of lime in combination
with the production of the sub-products herein before mentioned.
1000