Manufacturing,
Year: 1886

page_text: Manufacturing, the same.
I, HERBERT JOHN. ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention which.
has been communicated to me from abroad by Walter Seldon Pierce of the City,
and State of New York, United States of America, Manufacturer, 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 the manufacture of those compounds known as
chemical fertilizers and includes, first, a novel process or mode of producing a
fertilizer from natural or mineral phosphates: second, the several steps or parts of
such process, and third, the material produced thereby. I will describe the general
nature of the invention and in what manner the same may be carried out, and how
varied or modified.
The usual method of producing fertilizers of this character is to treat the natural
phosphates of lime with sulphuric or other acid, whereby the insoluble tribasic
phosphate is converted more or less completely and according to the acid used and
other mechanical conditions, into "super" ""acid" or "monobasic" phosphate which
is soluble in water, or into "reverted" or "bibasic" phosphate, which is soluble in
a solution of citrate of ammonium.
On the other band, the mineral phosphates of aluminum and iron have been
treated in the same or in a substantially similar manner, but the product in this
case is a wet, gelatinous mass, composed chiefly of the sulphates of aluminuın and
iron, free phosphoric acid, neutral phosphates of aluminium and iron, partially
soluble in free phosphoric acid and water. Even when this wet, sticky mass has
been dried by heat, being deliquescent, it afterwards becomes wet again by
absorption of moisture from the air.
Various processes have been proposed for the treatment of these minerals to
produce a fertilizing compound in a good dry mechanical condition, among which
processes is one discovered by me and which consists in mixing with the phosphoric
a proper quantity of the sulphate of ammonium or its equivalent and treating this

page_text: °
mixture with sulphuric or other acid. The present invention, as will-hereinafter
appear, has generally the same object in view.
The invention relates particularly to the treatment of that class of phosphorites
which contain, primarily, the phosphates of the tetratomic metals, aluminum
and iron, and secondarily, the phosphates of the diatomic metals, calcium and
magnesium, or combinations, chemical or mechanical, in any proportions of two or
more of the same.
The particular objects of the invention may be stated as follows-
1st To render soluble a larger proportion of the fertilizing principle contained in
the mineral than has heretofore been done; or, in other words, to obtain from the
mineral an increased proportion of phosphoric acid in a soluble condition, as
distinguished from those conditions known in the art as " reverted or "insoluble."
2nd To obtain a product in a dry and good mechanical condition, and which, not
being deliquescent, will remain dry.
"
3rd To obtain these results by the addition of only such substances as possess in
themselves recognized valuable fertilizing principles.
The simplest, and on some accounts the best method of carrying out the
invention is as follows-
I pulverize and dry or calcine the phosphorites, if either be necessary, either to
expel an excess of moisture or in order to render more perfect the contact and
incorporation therewith of the materials afterwards used, such contact being
essential to the completeness of the subsequent chemical reactions. I then
thoroughly incorporate with a given quantity of the phosphorites a suitable
quantity of chloride of sodium or common salt, and thereafter I add a suitable
quantity of the sulphate of ammonium, either dry, or in a hot or cold solution, and
I then subject the mixture to the action of a suitable quantity of sulphuric acid of
a degree of concentration proportioned to the composition of the phosphorite to be
treated or its solubility in acid. This mixture must be stirred to form perfect
contact of the ingredients, and a consequent more complete reaction.
resulting semi-liquid mass is then heated at a temperature of about sixty degrees
centigrade, for a few hours, or until it becomes dry and in a condition to be
pulverized.
The objects of this treatment are:-
The
1st To liberate a portion of the phosphoric acid from its combination with its
original base or bases, in which combination it is insoluble, and re-combine such
liberated portion with the sodium and ammonium so as to form a salt or salts,
soluble in water.
1.
2nd To liberate another portion of the phosphoric acid from its combination with
its original base or bases as free phosphoric acid, which thereafter acts as a dis.
solvent of the remaining neutral phosphates (themselves insoluble in water) the
resulting acid solution being soluble in water.
3rd To form a new salt or salts, which takes up the base or bases set free by the
liberation of a portion of the phosphoric acid as above described.,
4th To form a new salt or new salts capable of absorbing (either mechanically, or
chemically for the necessities of crystallization) any excess of water contained in
the phosphorites or in the acid solvent or in the water of solution of the salts added
with the acid.
i
i..
There are a number of substances which I may use in this process of manufacture
as substitutes for those named, and this will now more fully appear from the stated
objects of the treatment described. For example, in lieu of adding to the pulverized
mineral, chloride of sodium; I may use in place of the. latter the oxide, nitrate
sulphate or carbonate of sodium, or the acid sulphate of sodium known as, salt
cake. On the other hand I may use the chloride of potassium or the oxide, nitrate
sulphate or carbonate of potassium; and in general; (the oxides or any salt or salts
of the alkalis sodium or potassium).
In the second place I do not limit myself to the use of sulphate of ammonium,
for in its stead I may use such equivalents therefor as the carbonate, chloride or

page_text: nitrate or any other salt of ammonium, the ammoniacal liquor of gas works or an
organic body containing nitrogen. Or I may even omit altogether the sulphate of
ammonium or its equivalent and still obtain a new and highly useful result:
The particular method of mixing the salt or salts with the phosphorite is in
many respects unimportant. For example, the salt or sálts may be added either
dry or in a hot or cold solution or they may be dissolved in the acid and this
solution added to the phosphorite.
These are matters, however, well understood by those skilled the art, and
are determined by the solubility of the particular salt at different temperatures.
Further; instead of sulphuric acid I may use any acid; such as hydro-chloric or
nitric, which will set free the phosphoric acid, when the solvent acid is combined
with or applied to the material in the treatment of the same for the purpose
set forth.
I would also state that the object of heating the material as above described is
not to expel moisture and in that manner to dry the mixture, but to favor the
complete chemical reaction; whereby a new salt or new salts are formed, capable of
absorbing moisture. To obtain practically the same result, therefore; the ingredients
of the compound may be heated before mixing, in which case no subsequent heating
may be necessary.
The proportions of the several ingredients used will vary somewhat according to
circumstances. The following examples, however, will serve as illustrations.
In treating a phosphoríte consisting principally of the phosphates of iron and
alumina, such as those from the islands of Redonda and Grand Connetable; and
other similar deposits, I find the following proportions by weight to give good
results.
Dried phosphite, 2,000. Chloride of sodium dissolved in its own weight of
water, 200 to 400. Sulphate of ammonium, also dissolved in its own weight of
water, 400 to 800. Sulphuric acid of about.51 degrees, Baumé; ordinarily known'
as "chamber" acid, 1200 to 1600.
If the sulphate of ammonium be omitted, then the following proportions by weight
should be used.
Dried phosphate rock or phosphorite, 2000. Sulphate of potassium, dissolved in
its own weight of water; 600 to 900, and sulphuric acid of 51 degrees Baumé, 1200
to 1600.
In treating a phosphorite consisting principally of the phosphate of lime, but
containing also a considerable quantity of the phosphates of iron and alumina,
such as those from the island of Navassa, I should use the following proportions by
weight.
Dried phosphorite, 2000. Chloride of potassium, dissolved in its own weight
of water, 200 to 300. Sulphate of ammonium, also dissolved in its own weight of
water, 400 to 700. Sulphuric acid of 51 degrees, Baumé, 1400 to 1800.
As another example: in treating a phosphorite analyzing as follows:-Phosphoric
acid 39-44, alumina 20.93, iron oxide 8-83, lime 104, silica 1.11, water 28.52.
I should combine with 2,505 pounds of the uncalcined phosphorite, or 2,000 pounds
of the calcined phosphate rock or phosphorite, 1400 pounds of sulphuric acid,
730 pounds of sulphate of ammonium, 250 pounds of sea salt, and 978 pounds of
water.
In practice I find that my process not only gives a product in good, dry,
mechanical condition, which is not the case when the phosphate of alumina and
iron are treated with sulphuric acid alone, but that my product contains a much
larger percentage of soluble phosphoric acid than the latter.
Secondly, that my process yields a product, which, unlike the process used in
the treatment of the phosphates of lime, contains little or no phosphates in a
"reverted" form, as that term is applied to the phosphates of lime, but is almost
wholly composed of neutral phosphates in conjunction with sufficient free phos-
phoric acid to form soluble acid phosphates, although such salts cannot be isolated
in a solid or crystallized form, the remaining very small percentage of insoluble

page_text: phosphates representing the portion of phosphate rock unattacked by the sulphuric
acid. This absence of a reverted form of phosphate is not made manifest by the
usual methods of analysis applied to the phosphates of lime, owing to the precipita-
tion in the filter of a portion of neutral phosphate out of its solution in free
phosphoric acid when such acid solution is neutralized by the addition of water.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is;
:
First. The process of manufacturing fertilizing compounds from the mineral
phosphorites herein described which consists in treating or mixing the phosphorite
with an oxide or salt of sodium or potassium and an acid substantially as herein
set forth.
Second. The process of manufacturing fertilizing compounds from mineral
phosphorites which consists in treating or mixing the phosphorite with an oxide
or salt of either sodium or potassium, sulphate of ammonium or its equivalent and
acid, as herein set forth.
Third. The process of manufacturing fertilizing compounds from mineral
phosphorites which consists in combining with the mineral suitable proportions
of an oxide or salt of sodium or potassium, sulphate of ammonium, or its equivalent
and acid, and heating the mixture for a given time, substantially as and for the
purpose set forth.
Fourth. The process which consists in combining or mixing with pulverized and
dry or calcined phosphorite, chloride of sodium or its equivalent, and sulphuric or
other proper acid in the proportion specified and then heating the mixture, as
⚫herein set forth.
.
Fifth. The process which consists in combining or mixing with pulverized and
dry or calcined phosphorite, chloride of sodium or its equivalent, sulphate of
ammonium or its equivalent and sulphuric or other acid, in the proportions and
manner herein set forth.
Sixth. The process which consists in combining or mixing with pulverized and
dry or calcined phosphorite, chloride of sodium, sulphate of ammonium and
sulphuric acid or the equivalents of these in substantially the proportions set forth,
then maintaining the compound at a temperature of 60 degrees centigrade or
thereabouts for a given time to perfect the chemical reaction as set forth.
Seventh. The product resulting from the herein described process consisting of a
fertilizing compound in a dry and good mechanical condition and composed of the
ingredients herein described.